HomeMy WebLinkAboutAllentown Truck Reroute - FINAL Environmental Impact Statement (FEIS) (Dated 6/9/2025)" 11111.1111,
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i8dentown Truck Reroute
Project
State Environmental Policy Act Final Environmental
impact Statement
Tukwila, Washington
June 9, 2025
Cove r
Cover Letter
City of Tukwila
June 9, 2025
Dear Interested Parties, Jurisdictions, and Agencies,
The City of Tukwila (the City) is issuing this Final Environmental Impact Statement (FEIS) for the
Proposed Allentown Truck Reroute Project (the Proposed Project). The City is proposing to reroute
the freight truck traffic that uses streets in Allentown, a residential neighborhood in Tukwila, to access
BNSF Railway's South Seattle Intermodal Facility. The purpose of this EIS is to assist the City in
Selecting a Preferred Alternative that will improve safety and the quality of life in Allentown without
compromising the operations of the BNSF intermodal facility.
The FEIS has been prepared to satisfy the requirements of the Washington State Environmental Policy
Act (SEPA). The FEIS evaluates the probable significant environmental impacts from the construction
and operation of the Proposed Alternatives and their contribution to cumulative environmental
impacts. The Proposed Alternatives evaluated in the EIS are the No Action Alternative, Alternative 2,
Alternative 3B, and Alternative 4. The City will select a preferred Alternative after considering the
results of this FEIS.
The following resource areas are evaluated in the FEIS:
• Geology and Soils
• Water Resources
• Plants and Animals
• Land Use, Shoreline Use, and
Recreation
• Air Quality and Greenhouse Gas
• Transportation
ii
• Health and Safety
• Public Services and Utilities
• Cultural Resources
• Noise
• Environmental Justice
• Visual Resources and Aesthetics
The FEIS proposes mitigation to address adverse environmental impacts of the Proposed Project
Alternatives identified in the review. In some cases, the mitigation measures would reduce, but not
completely eliminate, potential adverse effects of Alternatives, and could, if selected, have the
potential to result in significant unavoidable impacts. For example, Alternative 2 has the potential to
create unavoidable significant impacts to Geology and Soils, Cultural Resources, and Visual Resources
and Aesthetics. For that reason, Alternative 2 has been determined to be unfeasible and will not be
considered for future project -level planning and design. However, because of the public support that
Alternative 2 received during project scoping, it is being included in the EIS to demonstrate that it has
been thoroughly and accurately studied, and that analysis of this alternative conforms with SEPA
guidelines and requirements.
Sincerely,
Mark Hafs
Project Director
City of Tukwila
iii
Fact S
Pr
•
p
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sed Project Tittle
Allentown Truck Reroute Project
feet
Description of Proposed Project Alternatives
The Applicant's Proposed Project is to develop an alternative route to the BNSF Intermodal Facility in
Allentown to improve livability and safety in Allentown without compromising the operations of the
intermodal facility.
Location
The Allentown neighborhood is located in the northeast portion of the City of Tukwila, King County,
Washington. Allentown's boundaries are formed by the right-of-way for a Seattle City Light transmission
corridor to the north, 1-5 and BNSF's South Seattle Intermodal Facility to the east, and the Duwamish
River to the south and west.
Applicant (Pr
I�
Irn e nt)
The City of Tukwila
Proposed Date of °impllementat'io n
To Be Determined
Lead Aelrncy
The City of Tukwila, Washington
Res
DOinsi
Dlle Official
Nora Gierloff, Director
City of Tukwila Department of Community Development
Lead A elrncy Contact Person
Mark Hafs
6200 Southcenter Boulevard
Tukwila, WA 98188
Required IPelrlmits, Licenses, and Apl
To Be Determined
DrovaVs
iv
Auth
•
IFedeirall
Tr'iball
Washington State
LocaV
rs and PriinclipeII Contributors
This document has been prepared under the direction of the City of Tukwila. All sections and appendices
have been prepared for and approved by the City of Tukwila. Key authors and principal contributors to
the analyses are listed below.
HDR, Inc.
600 University Street, Suite 500
Seattle, WA 98101
Date of Draft ZEDS Ilssuance
March 11, 2025
Topic(s)
Geology and Soils, Water Resources, Plants and
Animals; Land Use, Shoreline Use, and
Recreation; Air Quality and Green House Gas;
Transportation; Health and Safety; Public Services
and Utilities; Cultural Resources; Noise;
Environmental Justice; Visual Aesthetics;
Cumulative Impacts
Ta oIe of Contents
1 Summary 1
1.1 Introduction 1
1.2 Project Applicant 1
1.3 Project Objective 1
1.4 Project Description 1
1.4.1 Project Location 1
1.5 Public Involvement/Scoping Summary 5
1.6 Summary of Environmental Impacts and Mitigation Measures 5
1.7 Unavoidable Significant Adverse Impacts 7
2 Introduction 8
2.1 Project Overview 8
2.2 Summary of the Environmental Review Process 8
2.2.1 EIS Scoping Process 8
2.2.2 Draft EIS Preparation, Publication, and Review 9
2.2.3 Final EIS Publication 10
2.3 Document Organization 10
3 Project Objective, Project Alternatives, and No Action Alternative 11
3.1 Intro 11
3.2 Applicant's Project Objective 11
3.3 Description of the No Action Alternative 11
3.4 Description of Project Alternatives 13
3.4.1 Alternative 2: Airport Way South 13
3.4.2 Alternative 3B: Improvements to 48th Place South 17
3.4.3 Alternative 4: New Bridge from SR 900 (MLK Jr Way) to South 129th Street 20
3.5 Alternatives Removed from Further Consideration 24
3.5.1 Alternative 1: Extension of South 112th Street, East Marginal Way South to BNSF along
Utility Right -of -Way 24
3.5.2 Alternative 3A: Gateway Drive to 48th Place South 25
3.5.3 Alternative 5: 1-5 Access 25
3.6 Benefits and Disadvantages of Delaying Project Implementation 26
4 Environmental Analysis 27
vi
4.1 Geology/Soils 27
4.1.1 Affected Environment 27
4.1.2 Relevant Plans Policies and Regulations 48
4.1.3 Methodology 49
4.1.4 Impacts Analysis 50
4.1.5 Mitigation Measures 52
4.1.6 Significant Unavoidable Adverse Impacts 54
4.2 Water Resources (Floodplains, Wetlands, Water Quality, Surface Water, Groundwater) 55
4.2.1 Affected Environment 57
4.2.2 Relevant Plans Policies and Regulations 70
4.2.3 Methodology 72
4.2.4 Impacts Analysis 73
4.2.5 Mitigation Measures 90
4.2.6 Significant Unavoidable Adverse Impacts 92
4.3 Plants and Animals 93
4.3.1 Affected Environment 93
4.3.2 Relevant Plans Policies and Regulations 129
4.3.3 Methodology 131
4.3.4 Impacts Analysis 133
4.3.5 Mitigation Measures 149
4.3.6 Significant Unavoidable Adverse Impacts 153
4.4 Land Use, Shoreline Use, and Recreation 154
4.4.1 Affected Environment 154
4.4.2 Relevant Plans, Policies, and Regulations 159
4.4.3 Methodology 161
4.4.4 Impacts Analysis 161
4.4.5 Mitigation Measures 179
4.4.6 Significant Unavoidable Adverse Impacts 180
4.5 Air Quality and Greenhouse Gas 181
4.5.1 Affected Environment 181
4.5.2 Relevant Plans, Policies, and Regulations 184
4.5.3 Methodology 191
4.5.4 Impacts Analysis 192
vi i
4.5.5 Mitigation Measures 193
4.5.6 Significant Unavoidable Adverse Impacts 193
4.6 Transportation 194
4.6.1 Affected Environment 194
4.6.2 Relevant Plans Policies and Regulations 197
4.6.3 Methodology 197
4.6.4 Impacts Analysis 200
4.6.5 Mitigation Measures 210
4.7 Health and Safety 212
4.7.1 Affected Environment 212
4.7.2 Relevant Plans Policies and Regulations 222
4.7.3 Methodology 223
4.7.4 Impacts Analysis 224
4.7.5 Mitigation Measures 225
4.8 Public Services and Utilities 227
4.8.1 Affected Environment 227
4.8.2 Relevant Plans Policies and Regulations 229
4.8.3 Methodology 231
4.8.4 Impacts Analysis 231
4.8.5 Mitigation Measures 234
4.9 Cultural Resources 235
4.9.1 Affected Environment 235
4.9.2 Relevant Plans, Policies, and Regulations 244
4.9.3 Impacts 244
4.9.4 Mitigation Measures 249
4.9.5 Significant Unavoidable Adverse Impacts 250
4.10 Noise 252
4.10.1 Affected Environment 252
4.10.2 Relevant Plans Policies and Regulations 260
4.10.3 Impacts 263
4.10.4 Mitigation Measures 266
4.10.5 Significant Unavoidable Adverse Impacts 267
4.11 Environmental Justice 268
viii
4.11.1 Affected Environment 270
4.11.2 Relevant Plans, Policies, and Regulations 289
4.11.3 Methodology 289
4.11.4 Impacts Analysis 291
4.11.5 Mitigation Measures 295
4.11.6 Environmental Justice Determination 295
4.12 Visual Resources and Aesthetics 296
4.12.1 Affected Environment 296
4.12.2 Relevant Plans Policies and Regulations 318
4.12.3 Methodology 320
4.12.4 Impacts Analysis 322
4.12.5 Mitigation Measures 326
4.12.6 Significant Unavoidable Adverse Impacts 327
5 Cumulative Impacts 328
5.1 Methodology 328
5.1.1 Reasonably Foreseeable Future Actions (RFFA) 328
5.2 Cumulative Impact Analysis 330
5.2.1 Geology and Soils 330
5.2.2 Water Resources 330
5.2.3 Plants and Animals 331
5.2.4 Land Use, Shoreline Use, and Recreation 332
5.2.5 Air Quality and Greenhouse Gas 333
5.2.6 Transportation 334
5.2.7 Health and Safety 335
5.2.8 Public Services and Utilities 336
5.2.9 Cultural Resources 336
5.2.10 Noise 337
5.2.11 Environmental Justice 338
5.2.12 Visual Resources and Aesthetics 339
6 References 340
7 Appendices 353
Appendix A: Public Comments and Response to Public Comments A
Appendix B: Plan Sheets For the Alternatives B
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Appendix C: Wetland and Stream Technical Report C
Appendix D: Allentown EIS Intersection Study D
Appendix E: Precontact, Ethnographic, and Historic Context for Cultural Resources within the Study
Area E
Ta
tiles
Table 1.6-1 Potential impacts and proposed mitigation measures for each Alternative 5
Table 2.2-1 Issues Identified 8
Table 3.6-1 Benefits and Disadvantages of proposed Project Implementation Delay 26
Table 4.1-1. Regulations and Policies for Geology and Soils 48
Table 4.1-2. Impact Magnitude and Description 49
Table 4.2-1 Summary of Wetlands within the Project Study Areas 63
Table 4.2-2 Summary of Streams within the Study Area 66
Table 4.2-3 Duwamish River Section 303(d) Category 5 parameters 67
Table 4.2-4 Surface water issues in Tukwila affecting the Duwamish River 67
Table 4.2-5 Relevant Plans, Policies, and Regulations 70
Table 4.2-6 Impact magnitude and description 73
Table 4.2-7 Land Cover within Alternative 2 78
Table 4.2-8 Wetland Impacts in the Alternative 2 Study Area 79
Table 4.2-9 Landcover of Alternative 3B 84
Table 4.2-10 Direct impacts to wetlands in the Alternative 3B study area 84
Table 4.2-11 Landcover of Alternative 4 89
Table 4.2-12 Direct impacts to wetlands in Alternative 4 study area 90
Table 4.3-1 Summary of Wetlands within the Project Study Areas 100
Table 4.3-2 Summary of Streams within the Study Area 104
Table 4.3-3 Animal species of concern with potential to be in or near the action area 111
Table 4.3-4 Landcover classification of the No Action Alternative 116
Table 4.3-5 Landcover classification of Alternative 2 118
Table 4.3-6 Landcover classification of Alternative 3B 118
Table 4.3-7 Landcover classification of Alternative 4 120
Table 4.3-8 Animal species of concern with potential to be in or near the action area 124
Table 4.3-9 Vascular plant species of concern with potential to be in the action area 127
Table 4.3-10 Relevant Plans, Policies, and Regulations 130
Table 4.3-11 Terrestrial action area for a range of sound produced by construction equipment 132
Table 4.3-12 Impact Magnitude and Description 133
Table 4.3-13 Landcover for the No Action Alternative 137
Table 4.3-14 Direct long-term impacts to wetlands in Alternative 2 study area 139
Table 4.3-15 Land cover of Alternative 2 139
Table 4.3-16 Direct long-term impacts to wetlands in the Alternative 3B study area 142
Table 4.3-17 Land cover of Alternative 3B 143
Table 4.3-18 Direct long-term impacts to wetlands in Alternative 4 study area 147
Table 4.3-19 Land cover of Alternative 4 148
x
Table 4.4-1. Land Use Districts and Descriptions within the proposed Alternatives 154
Table 4.4-2. Relevant Plans, Policies, and Regulations 159
Table 4.4-3. Impact Magnitude and Description 161
Table 4.4-4. Impact Summary Table 178
Table 4.5-1 Summary of Relevant Air Quality and GHG Laws, Regulations, Plans, and Policies 184
Table 4.5-2 Federal and State Ambient Air Quality Standards 188
Table 4.6-1 Project Alternatives and Associated Intersections 195
Table 4.6-2 Regulations and Policies for Transportation 197
Table 4.6-3 Delay Performance Indicators for Intersection LOS 198
Table 4.6-4 Pavement Conditions and Associated Descriptive Terms 200
Table 4.6-5 Impact Magnitude and Description 200
Table 4.6-6 2024 Synchro LOS and Delay Results (without Detour) 202
Table 4.6-7 2045 Synchro LOS and Delay Results 202
Table 4.6-8 Results of Annual Vehicle Miles Traveled (VMT) for Alternatives 204
Table 4.6-9 Crash Data Summary 2019-2023 for Six Study Intersections 207
Table 4.6-10 Crash Data Summary 2019-2023 for Six Study Intersections by Severity 207
Table 4.6-11 Comparison of PCI between Alternatives 208
Table 4.6-12 Impact Summary Table 210
Table 4.7-1 No Action Alternative — Confirmed and Suspected Contaminated Sites within 0.5 mile 213
Table 4.7-2. Alternative 2 — Confirmed and Suspected Contaminated Sites within 0.5 mile 215
Table 4.7-3. Alternative 3B — Confirmed and Suspected Contaminated Sites within 0.5 mile 217
Table 4.7-4. Alternative 4 — Confirmed and Suspected Contaminated Sites within 0.5 mile 219
Table 4.7-5. Applicable Policies and Regulations for Health and Safety 222
Table 4.7-6. Impact Magnitude and Description 223
Table 4.8-1 Utility Services and Providers within the Study Area 227
Table 4.8-2. Applicable Policies and Regulations for Public Services and Utilities 230
Table 4.8-3. Impact Magnitude and Description 231
Table 4.9-1. Individually eligible and contributing SPAA Facility Historic District resources included in the
impact analysis and keyed to map in Figure 4.9-1 240
Table 4.9-2. Individually eligible historic property not associated with the SPAA Historic District. 242
Table 4.9-3. Proposed Alternative Study Areas and probabilities to impact present cultural resources 247
Table 4.10-1 Typical Source Noise Levels 252
Table 4.10-2 Typical Residential Noise Levels 260
Table 4.10-3 Washington Administrative Code Noise Limits 261
Table 4.10-4 King County Code Noise Limits 262
Table 4.10-5 City of Tukwila Municipal Code Noise Limits 263
Table 4.10-6 Impact Magnitude and Description 264
Table 4.11-1 Population by Race/Ethnicity (No Action Alternative) 270
Table 4.11-2 Population by Race/Ethnicity (Alternative 2: Airport Way South) 273
Table 4.11-3 Population by Race/Ethnicity (Alternative 3B: Improvements to 48th Place South) 275
Table 4.11-4 Population by Race/Ethnicity (Alternative 4: New Bridge from SR 900) 277
Table 4.11-5 Population Below Poverty Level (No Action Alternative) 280
Table 4.11-6 Population Below the Poverty Level (Alternative 2: Airport Way South) 282
Table 4.11-7 Population Below Poverty Level (Alternative 3B: Improvements to 48th Place South) 284
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Table 4.11-8 Population Below Poverty Level (Alternative 4: New Bridge from SR 900) 286
Table 4.11-9 Relevant Plans, Policies, and Regulations 289
Table 4.11-10 Magnitude of impacts 290
Table 4.12-1 Land Use Zoning within the AVE for the No Action Alternative 299
Table 4.12-2 Recreational Areas within the AVE for the No Action Alternative 300
Table 4.12-3 Land Use Zoning within the AVE for Alternative 2 303
Table 4.12-4 Recreational Areas within the AVE for Alternative 2 304
Table 4.12-5 Landcover type and percentage of the Alternative 2 Footprint 304
Table 4.12-6 Land Use Zoning within the AVE for Alternative 3B 309
Table 4.12-7 Recreational Areas within the AVE for Alternative 3B 310
Table 4.12-8 Landcover type and percentage of the Alternative 3B Footprint 310
Table 4.12-9 Land Use Zoning within the AVE for Alternative 4 316
Table 4.12-10 Recreational Areas within the AVE for Alternative 4 317
Table 4.12-11 Landcover type and percentage of the Alternative 4 Footprint 317
Table 4.12-12 Relevant Plans, Policies, and Regulations 318
Table 4.12-13 FHWA Visual Character Compatibility Matrix 321
Table 4.12-14 Impacts to Visual Quality Matrix 321
Table 4.12-15 Impact Magnitude and Description 322
Table 4.12-16 Impact Summary Table 326
Table 5.1-1 RFFAs within the Study Areas of the Analyzed Resources 329
Figures
Figure 1.4-1 Allentown Truck Reroute Project Vicinity 3
Figure 1.4-2 Allentown and Locations for Proposed Alternatives 4
Figure 3.3-1. Overview of the No Action Alternative 12
Figure 3.4-1. Overview of Alternative 2 15
Figure 3.4-2. Feature Details for Alternative 2 16
Figure 3.4-3 Overview of Alternative 3B 18
Figure 3.4-4. Feature Details for Alternative 3B 19
Figure 3.4-5. Overview of Alternative 4 21
Figure 3.4-6. Feature Details for Alternative 4, Southern Portion 22
Figure 3.4-7. Feature Details for Alternative 4, Northern Portion 23
Figure 4.1-1. Soils Mapped in for the No Action Alternative 28
Figure 4.1-2. Soils Mapped in Alternative 2 Study Area 29
Figure 4.1-3. Soils Mapped in Alternative 3B Study Area 30
Figure 4.1-4 Soils Mapped in Alternative 4 Study Area Southern Portion 31
Figure 4.1-5 Soils Mapped in Alternative 4 Study Area Northern Portion 32
Figure 4.1-6. Potential Geologic Instabilities/Landslide Hazard Areas for the No Action Alternative 35
Figure 4.1-7. Potential Geologic Instabilities/Landslide Hazard Areas for Alternative 2 36
Figure 4.1-8. Potential Geologic Instabilities/Landslide Hazard Areas for Alternative 3B 37
Figure 4.1-9. Potential Geologic Instabilities/Landslide Hazard Areas for Alternative 4, Southern Portion
38
xii
Figure 4.1-10 Potential Geologic Instabilities/Landslide Hazard Areas for Alternative 4, Northern Portion
39
Figure 4.1-11. No Action Alternative Liquefaction Susceptibility 43
Figure 4.1-12. Alternative 2 Liquefaction Susceptibility 44
Figure 4.1-13. Alternative 3B Liquefaction Susceptibility 45
Figure 4.1-14. Alternative 4 (Southern Portion) Liquefaction Susceptibility 46
Figure 4.1-15. Alternative 4 (Northern Portion) Liquefaction Susceptibility 47
Figure 4.2-1 Map of Water Resources Study Area 56
Figure 4.2-2 Flood Hazard Areas in Proximity to the Study Areas 59
Figure 4.2-3 Overview of aquatic study area for No Action Alternative and Alternatives 2, 3B, and 4 61
Figure 4.2-4 EPA impaired waterbody and NPDES permitted discharge sites (EPA n.d.) 69
Figure 4.2-5 Wetlands and Surface Waters within the No Action Alternative Study Area 74
Figure 4.2-6 Wetlands and Surface Waters within the Alternative 2 Study Area 76
Figure 4.2-7 Wetlands and Surface Waters within the Alternative 3B Study Area 81
Figure 4.2-8 Wetlands and Surface Waters within the Southern Portion of the Alternative 4 Study Area86
Figure 4.2-9 Wetlands and Surface Waters within the Northern Portion of the Alternative 4 Study Area87
Figure 4.3-1 Wetland study area for No Action Alternative 94
Figure 4.3-2 Wetland study area for Alternative 2 95
Figure 4.3-3 Wetland study area for Alternative 3B 96
Figure 4.3-4 Wetland study area for southern section of Alternative 4 97
Figure 4.3-5 Wetland study area for northern section of Alternative 4 98
Figure 4.3-6 Overview of aquatic study area for No Action Alternative and Alternatives 2, 3B, and 4 ...103
Figure 4.3-7 Aquatic study area for the No Action Alternative 106
Figure 4.3-8 Aquatic study area for Alternative 2 107
Figure 4.3-9 Aquatic study area for Alternative 3B 108
Figure 4.3-10 Aquatic study area for southern section of Alternative 4 109
Figure 4.3-11 Aquatic study area for northern section of Alternative 4 110
Figure 4.3-12 No Action Alternative land cover and terrestrial study area including 200-foot buffer115
Figure 4.3-13 Alternative 2 land cover and terrestrial study area including 200-foot buffer. 117
Figure 4.3-14 Alternative 3B land cover and terrestrial study area including 200-foot buffer. 119
Figure 4.3-15 Southern section of Alternative 4 land cover and terrestrial study area including 200-foot
buffer. 121
Figure 4.3-16 Northern section of Alternative 4 land cover and terrestrial study area including 200-foot
buffer. 122
Figure 4.3-17 Project Alternative footprints and potential terrestrial noise impact areas 123
Figure 4.4-1. Land Use for the No Action Alternative 162
Figure 4.4-2. Shoreline Designation and Recreation for the No Action Alternative 163
Figure 4.4-3. Land Use for Alternative 2 166
Figure 4.4-4. Shoreline Designation and Recreation for Alternative 2 167
Figure 4.4-5. Land Use for Alternative 3B 169
Figure 4.4-6. Shoreline Designation and Recreation for Alternative 3 170
Figure 4.4-7 Land Use for Alternative 4, Southern Portion 173
Figure 4.4-8. Shoreline Designation and Recreation for Alternative 4, Southern Portion 174
Figure 4.4-9. Land Use for Alternative 4, Northern Portion 175
Figure 4.4-10. Shoreline Designation and Recreation for Alternative 4, Northern Portion 176
Figure 4.6-1 Study Intersections and Alternative Footprints 196
Figure 4.6-2 Change in LOS and Delay Results from 2024 to 2025 for Intersection 1 through 6 203
Figure 4.6-3 Overview of Annual VMT by Alternatives 206
Figure 4.6-4 Pavement Condition Index (PCI) of the City of Tukwila 209
Figure 4.7-1. No Action Alternative- Confirmed and Suspected Contaminated Sites Mapped 214
Figure 4.7-2. Confirmed and Suspected Contaminated Sites Mapped within 0.5 mile of Alternative 2216
Figure 4.7-3. Confirmed and Suspected Contaminated Sites Mapped within 0.5 mile of Alternative 3B
218
Figure 4.7-4. Confirmed and Suspected Contaminated Sites Mapped within 0.5 mile of Alternative 4
(South) 220
Figure 4.7-5. Confirmed and Suspected Contaminated Sites Mapped within 0.5 mile of Alternative 4
(South) 221
Figure 4.9-1. Map of the recommended eligible SPAA Historic District keyed to Table 4.9-1 (Allen 2024).
241
Figure 4.9-2 Eligible S&WW/PSS/SLS&E/NP (BNSF) railroad in proximity to Alternative 2, 3B, 4, and the
No Action Alternative depicted on aerial imagery (Allen 2024). 243
Figure 4.10-1 Vicinity Map of Alternatives 254
Figure 4.10-2.Noise Study Area for the No Action Alternative
Figure 4.10-3. Noise Study Area for Alternative 2
Figure 4.10-4 Noise Study Area for Alternative 3B
Figure 4.10-5 Noise Study Area for Alternative 4 (South Portion)
Figure 4.10-6 Noise Study Area for Alternative 4 (North Portion)
Figure 4.11-1 Census Block Groups in the Study Area
Figure 4.11-2 Minority Population by Census Tracts in the No Action Alternative Study Area
Figure 4.11-3
Figure 4.11-4
Figure 4.11-5
Figure 4.11-6
Figure 4.11-7
Figure 4.11-8
Figure 4.11-9
Minority Population by Census Tracts in the Alternative 2 Study Area
Minority Population by Census Tracts in the Alternative 3B Study Area
Minority Population by Census Tracts in the Alternative 4 Study Area
Low -Income Population by Census Tracts in the No Action Alternative Study Area
Low -Income Population by Census Tracts in the Alternative 2 Study Area
Low -Income Population by Census Tracts in the Alternative 3B Study Area
Low -Income Population by Census Tracts in the Alternative 4 Study Area
Figure 4.12-1 AVE and Key View for the No Action Alternative
Figure 4.12-2 AVE and Key View for Alternative 2
Figure 4.12-3 Alternative 2 Key View (01/31/2025)
Figure 4.12-4 AVE for Alternative 3B
Figure 4.12-5 Key Views and 2D modelled approximation of Alternative 3B
Figure 4.12-6 Current Key View from Trail 1 Location (November 6, 2024)
Figure 4.12-7 AVE and Key Views for Alternative 4
Figure 4.12-8 Digital Rendering of Alternative 3B from Key View Trail 1
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Acronyms anc
A
3
oreviations
AADT
Annual Average Daily Traffic
ACS
American Community Survey
Al
Area of Impacts
Alt
Alternative
ANSI
American National Standards Institute
AQ
Air Quality
AVE
Area of Visual Effect
BCC
Bird of Conservation Concern
BCR
Bird Conservation Regions
BHC
Benzene Hexachloride
BMP
Best Management Practice
BNSF
BNSF Railway Company
BP
Before Present
CARA
Critical Aquifer Recharge Area
CE
Categorical Exclusion
CEQ
Council on Environmental Quality
CERCLA
Comprehensive Environmental Response, Compensation, and Liability Act
CFR
Code of Federal Regulations
City
City of Tukwila
CLI
Commercial Light Industrial
CWA
Clean Water Act
DAHP
Department of Archaeology and Historic Preservation
dB
Decibels
dBA
A -Weighted Decibels
DDD
Dichlorodiphenyldichloroethane
DDE
Dichlorodiphenyldichloroethylene
DDT
Dichlorodiphenyltrichloroethane
DNR
Department of Natural Resources
DPM
Diesel Particulate Matter
DPS
Distinct Population Segment
Ecology
Washington State Department of Ecology
EDNA
Environmental Designation for Noise Abatement
EEM
Estuarine Emergent
EIS
Environmental Impact Statement
EJ
Environmental Justice
EO
Executive Order
EPA
Environmental Protection Agency
ESU
Evolutionary Significant Unit
FEMA
Federal Emergency Management Association
FGDC
Federal Geographic Data Committee
FHWA
Federal Highway Administration
XV
FIRM
Flood Insurance Rate Maps
FTA
Federal Transportation Administration
FWHCA
Fish and Wildlife Habitat Conservation Areas
GHG
Greenhouse Gas
GIS
Geographic Information Systems
GMA
Growth Management Act
GPS
Global Positioning System
HAP
Hazardous Air Pollutant
HASP
Health and Safety Plan
HCM
Highway Capacity Manual
HDR
HDR, Inc.
HDR
High Density Residential
HEAL
Healthy Environment for All
HGM
Hydrogeomorphic
HI
Heavy Industrial
HPA
Hydraulic Project Approval
HTL
High Tide Line
I
Interstate
ICE
Infrastructure Carbon Estimator
KCC
King County Code
KCGWV
King County Groundwater Well Viewer
KCHPP
King County Historic Preservation Program
KCHRI
King County Historic Resource Inventory
KCLR
King County Landmarks Register
KCSPPM
King County Stormwater Pollution Prevention Manual
KOP
Key Observation Point
LDR
Low Density Residential
LEP
Limited English Proficiency
LLC
Limited Liability Company
LOS
Level of Service
LRTP
Long -Range Transportation Plan
MBTA
Migratory Bird Treaty Act
MIC/H
Manufacturing Industrial Center/ Heavy
MIDP
Monitoring and Inadvertent Discovery Plan
MLK
Martain Luther King Junior
MML
Maritime Manufacturing and Logistics
MOVES
Motor Vehicle Emissions Simulator
MPO
Metropolitan Planning Organization
MSAT
Mobile Source Air Toxic Analysis
MUO
Mixed Use Office
MVEB
Motor Vehicle Emissions Budget
N
North
NM
No Action Alternative
NAAQS
National Ambient Air Quality Standards
NB
Northbound
xvi
NETR
National Environmental Title Research
NFIP
National Flood Insurance Program
NOAA
National Oceanic and Atmospheric Association
NP
Northern Pacific Railroad
NPDES
National Pollutant Discharge Elimination System
NRCS
Natural Resources Conservation Service
NRHP
National Register of Historical Places
NWI
National Wetlands Inventory
OHWM
Ordinary High Water Mark
PCB
Polychlorinated Biphenyls
PCI
Pavement Condition Index
PEM
Palustrine Emergent
PFO
Palustrine Forested
PGIS
Pollution -Generating Impervious Surfaces
PHMSA
Pipeline and Hazardous Materials Safety Administration
PHS
Priority Habitats and Species
PM
Particulate Matter
ppm
Parts per Million
Project
Allentown Truck Reroute Project
PROS
City of Tukwila Parks, Recreation, Open Space Plan
PSCAA
Puget Sound Clean Air Agency
PSD
Prevention of Significant Deterioration
PSI
Pollution Standards Index
PSMFC
Pacific Marine Fisheries Commission
PSRC
Puget Sound Regional Council
PSS
Palustrine Scrub -Shrub
PSS
Puget Sound Shore Railroad Company
R
Residential
RCC
Residential Commercial Center
RCM
Regional Commercial Mixed use
RCW
Revised Code of Washington
RFFA
Reasonably Foreseeable Future Action
RM
Multi -family Residential
ROD
Record of Decision
ROW
Right -of -Way
RS
Single Family Residential
S
South
S&WW
Seattle and Walla Walla Railroad
SB
Southbound
SBCC
State Building Code Council
SEPA
State Environmental Policy Act
SFHA
Special Flood Hazard Areas
SHPO
State Historic Preservation Office
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SIP
State Implementation Plan
SLS&E
The Seattle, Lake Shore and Eastern Railway
SMC
Seattle Municipal Code
SMP
Shoreline Master Program
SPAA
Seattle Police Athletic Association
SPCC
Spill Prevention, Control, and Countermeasures
SPDARF
Seattle Police Department Alcoholics Rehabilitation Farm
SPDRP
Seattle Police Department Rehabilitation Program
SR
State Route
SSA
Sole Source Aquifer
STIP
Statewide Transportation Improvement Program
SWPPP
Stormwater Pollution Prevention Plan
TCP
Tukwila Comprehensive Plan
TCP
Traditional Cultural Places
TIP
Transportation Improvement Program
TMC
Tukwila Municipal Code
TMDL
Total Maximum Daily Load
TRB
Transportation Research Board
UP
Union Pacific Railroad
USACE
United States Corps of Engineers
USCB
United States Census Bureau
USDA
United States Department of Agriculture
USEPA
United States Environmental Protection Agency
USFWS
United States Fish and Wildlife Service
USGS
United States Geological Survey
VMT
Vehicle Miles Traveled
VOC
Volatile Organic Compounds
WA
Washington
WAC
Washington Administrative Code
WADNR
Washington Department of Natural Resources
WDFW
Washington Department of Fish and Wildlife
WHR
Washington Heritage Register
WISAA
Washington Information System for Architectural and Archeological Records
WOTUS
Waters of the United States
WRIA
Water Resource Inventory Area
WSDOT
Washington State Department of Transportation
WSSC
Washington Suburban Sanitary Commission
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S ul irml irml a iry
1.1 Il int roductlioin
The BNSF Railway Company's (BNSF) South Seattle Intermodal Facility in the Allentown neighborhood of
Tukwila, Washington is an important economic link to the Puget Sound Region. It serves as an inland
port, providing domestic intermodal transloading between truck and rail. Currently incoming trucks
access the BNSF intermodal facility from the South 129th Street Bridge to South 50th Place. Outgoing
trucks can use either the South 129th Street Bridge or take South 124th Street to the 42nd Avenue South
Bridge. After the planned replacement of the 42nd Avenue South Bridge, truck traffic will also be able to
access the BNSF intermodal facility by traveling south on the bridge and reach the facility via South
124th Street. To improve livability and safety in Allentown without compromising the operations of the
facility, the City is evaluating potential alternative freight truck access routes to the BNSF intermodal
facility.
The City of Tukwila (City) is the lead agency overseeing the preparation of an Environmental Impact
Statement (EIS) for the proposed Allentown Truck Reroute Project (Project) under the State
Environmental Policy Act (SEPA). Three proposed route alternatives, along with the existing truck route
(the No Action Alternative), will be analyzed in the EIS to determine their potential impacts on the built
and natural environments. These alternatives, which were developed through the scoping process, are
intended to reduce the impacts of truck traffic in residential and recreational areas. The alternatives are
described and discussed in detail in Section 3.
31_2 (Project Appllicant
The City of Tukwila (City) is the lead agency overseeing the preparation of an Environmental Impact
Statement (EIS) under the State Environmental Policy Act (SEPA) for the proposed Allentown Truck
Reroute Project (Project).
1_3 (Project Objective
The purpose and need for the Project are to develop an alternative route to the BNSF Intermodal Facility
in Allentown to improve livability and safety in Allentown without compromising the operations of the
intermodal facility.
3.A Project Descitihlptihoin
The existing truck route, which is the No Action Alternative, in addition to three proposed route
alternatives will be analyzed in the EIS to determine potential impacts on the built and natural
environment.
1.4.1 Project Location
The Allentown neighborhood is located in the northeast portion of the City of Tukwila, King County,
Washington, see Figure 1.4-1. Allentown's boundaries are formed by the right-of-way for a Seattle City
Light transmission corridor to the north, 1-5 and BNSF's South Seattle Intermodal Facility to the east, and
the Duwamish River to the south and west, see Figure 1.4-2.
Zoned for low -density residential development, land use in Allentown is primarily single-family housing,
along with several neighborhood parks, the Tukwila Community Center, and the Green River Trail.
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Natural areas include restored native habitat in the Duwamish Hill Reserve and Codiga Park, several
small wetlands, and the Duwamish River's riparian corridor. In addition to BNSF's South Seattle facility,
nearby land uses include the Gateway Corporate Center, single-family development in Tukwila's
Riverton neighborhood, and commercial development along 48th Avenue South. consisting primarily of
freight and truck -support services. Several major transportation facilities are in the vicinity of Allentown,
including 1-5 to the east and south, SR 599, Interurban Avenue and East Marginal Way to the west, and
an elevated section of Sound Transit's Link Light Rail line.
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1.5 PubIlic Onvollvement/Scoping Summary
The City held a Phase 1 formal scoping period February 14 through March 15, 2023, during which it
presented to the public several proposed truck route alternatives — three new alternatives and two
alternatives that were evaluated in the 2016 BNSF study. A Phase 2 scoping period was held May 3
through June 1, 2023, during which the City shared technical information about the proposed truck
route alternatives. After considering public comment, the City selected four truck route alternatives for
study; they are presented in this EIS.
Legal notices for both phases of scoping were published in the Seattle Times and Washington State
Environmental Policy Act (SEPA) Register. Notices of the scoping process were also distributed to select
agencies and businesses who might have an interest in the project.
1.6 Summary of Environmental impacts and (Mitigation Measures
The Project is considering four alternatives for the truck reroute design: three new proposed routes and
the No Action Alternative. Detailed descriptions of the alternatives are located in Section 3. A summary
of the potential environmental impacts and their proposed mitigation measures is presented in Table
1.6-1.
Table 1.6-1 Potential impacts and proposed mitigation measures for each Alternative
Alternative
Affected Resource and
Potential Environmental
Impact
Proposed Mitigation Measures
No Action
Alternative
Noise
Avoid impacts by selecting a different
alternative to the current operating conditions
Health and Safety
Visual Resources and
Aesthetics
5
Alternative
Affected Resource and
Potential Environmental
Impact
Proposed Mitigation Measures
Alternative 2:
Airport Way S
Visual Resources and
Aesthetics
Use directional, shaded lighting; privacy/noise
wall and landscaping
Cultural resources
Avoid impacts by selecting a different
alternative.
Consult with Indian Tribes regarding impacts to
TCPs, known place names, Tribal resources, and
U&A fishing grounds.
Design and site construction to avoid significant
impacts to cultural and Tribal resources,
including access to U&A fishing grounds.
Conduct an archaeological survey prior to
construction.
Include Tribal and archaeological monitors
during Project construction and develop a MIDP
prior to construction.
Recreation
Relocate the Seattle Police Athletic Association
training facility
Noise
Construct a noise wall and landscaping
Alternative 3B:
Improvements to
48th PI S
Water Resources
Avoid impacts to the greatest extent possible by
employing best management practices; restore
create, or enhance additional wetlands for
impact compensation
Visual Resources and
Aesthetics
Bridge design, landscaping, directional, shaded
lighting
Noise
Construct a noise wall and increase vegetative
cover with landscaping
Cultural Resources
Consult with Indian Tribes regarding impacts to
TCPs, known place names, Tribal resources, and
U&A fishing grounds.
Design and site construction to avoid significant
impacts to cultural and Tribal resources,
including access to U&A fishing grounds.
Conduct an archaeological survey prior to
construction.
Include Tribal and archaeological monitors
during Project construction and develop a MIDP
prior to construction.
6
Alternative
Affected Resource and
Potential Environmental
Impact
Proposed Mitigation Measures
Alternative 4: New
Bridge from SR
900
Land Use
Compensating property owners
Visual Resources and
Aesthetics
Directional, shaded lighting; privacy/noise wall
and landscaping
Transportation
Improve intersection at Martin Luther King Jr
Way & South 129th Street
Water Resources
Avoid impacts to the greatest extent possible by
employing best management practices; restore
create, or enhance additional wetlands for
impact compensation
Cultural Resources
Consult with Indian Tribes regarding impacts to
TCPs, known place names, Tribal resources, and
U&A fishing grounds.
Design and site construction to avoid significant
impacts to cultural and Tribal resources,
including access to U&A fishing grounds.
Conduct an archaeological survey prior to
construction.
Include Tribal and archaeological monitors
during Project construction and develop a MIDP
prior to construction.
1.7 Unavolidablle Significant Adverse Impacts
The impacts analyzed for each resource section that were determined to be significant would be
avoidable by selecting another Alternative. As there is no preferred alternative for this proposed Project,
the impacts must be weighed against each other equally rather than in relation to a "standard". Each of
the Alternatives presented in this EIS have trade-offs; they affect the resources in different ways and to
different degrees. The purpose of this Environmental Impact Statement is to find an alternate solution
to the current operating conditions of the traffic related to the BNSF facility- a solution that will reduce
truck traffic in residential and recreational areas.
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2 introduction
2 . ,3. Project Ove rvii ew
In 2015, the City of Tukwila undertook a study to find a new truck route that would reduce the impacts
of trucks in Allentown. This study, the BNSF Railway Intermodal Facility Access Study was completed at
the end of 2016. The study proposed four new alternative truck routes to the intermodal facility that
would not travel through residential streets of Allentown, and one alternative considered the impacts of
keeping the current truck route in place (City 2025). The City has held open houses where the public
provided input about the needs of their community and commented on the proposed truck route
alternatives. As a result of the BNSF access study and the public's input, the City has prepared this
Environmental Impact Statement to help the Allentown move forward in determining a solution for this
issue.
2.2 Summary of the Environmental Review Process
2.2.1 EIS Scoping Process
As a result of the scoping process discussed in Section 1.5, and through internal scoping, several issues
were documented in the scoping report (Tukwila 2023). The issues relevant to the SEPA analysis are
identified in Table 2.2-1 with the section where each issue is discussed in the EIS. Public comments and
public comment responses are provided in Appendix A.
Table 2.2--1 Issues Identified
Issues Identified During Scoping
Sections Where Issues are
Addressed
Air Quality/ Greenhouse Gas
Air quality as a serious concern for residents due to the amount of exhaust and
high levels of CO2 produced by trucks
Sections 4.5, 4.7, 4.11
Cultural Sites/ Resources
The current route, and potential route alternatives, could negatively affect resources
like the Duwamish Hill Preserve, the Duwamish River, wetlands, trails,
and the Chinook Winds mitigation project.
Sections 4.4, 4.9, 4.11
Health and Safety
Multiple comments specifically cited 6PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-
phenylenediamine) chemicals from truck tires and PAH (polycyclic aromatic
hydrocarbon) chemicals as a threat to neighborhood health.
Sections 4.2, 4.3, 4.7
Residents cited personal experiences of poor breathing and headaches due to constant
truck fumes in the neighborhood.
Sections 4.5, 4.7
Commenters noted safety concerns for neighborhood children, elderly, and other
pedestrians due to the consistent presence of large trucks.
Sections 4.4, 4.6, 4.7, 4.10
Noise
Commenters noted rumbling, reverse beeps, and general truck noise as an issue with
the current truck route and potential routes that pass through the neighborhood.
Section 4.10
Comments expressed difficulty sleeping as a direct consequence of truck noise.
Sections 4.7, 4.10
8
Issues Identified During Scoping
Sections Where Issues are
Addressed
Plants and Animals
Comments expressed concerns related to the wildlife in the area, specifically Coho
Salmon and other fish, birds, seals, otters, beavers, ducks, geese, rabbits, eagles, and
raccoons
Section 4.3
Comments noted the possible upheaval of trees for possible route alternatives as
having a negative effect on the environment.
Sections 4.3, 4.4, 4.12
A comment from the Duwamish Tribal Services Organization expressed, "While our
focus is on preserving our cultural resources, we also support and recommend the
removal of invasive species and noxious weeds and replace any proposed landscaping
with only native vegetation to increase habitat for native fish, wildlife, avian life and
pollinators."
Sections 4.3, 4.4, 4.9, 4.12
Public Services/ Utilities
Multiple comments noted poor road conditions and excessive wear and tear to
infrastructure due to consistent truck driving on residential roads.
Sections 4.6, 4.8
Social Elements and Environmental Justice
Commenters mentioned that cost played a large role in decision -making. Comments
noted that the potential cost of proposed alternative routes requiring new
infrastructure, like an additional bridge, was a negative factor
Sections 4.6, 4.8
Commenters emphasized the diversity of the neighborhood and stated that thorough
engagement is needed to communicate with everyone effected by the current, and
potentially new, truck route
Section 4.11
Traffic
Comments expressed frustration with the current use of roads by large trucks, which
block traffic in the neighborhood due to size and possible breakdowns.
Sections 4.6, 4.7, 4.8,
Commenters expressed concern that some alternatives may be confusing for truck and
residential drivers alike, which could create more traffic.
Section 4.6
A commenter suggested a thorough analysis of traffic impacts. Comment noted that
travel time and reliability are important criteria for truck freight performance.
Section 4.6
2.2.2 Draft EIS Preparation, Publication, and Review
This Draft EIS was prepared with the information and comments generated from the scoping process.
Several alternatives were analyzed for their feasibility; a final set of alternatives were determined to be
feasible actions, and some alternatives were eliminated from further analysis for reasons of
environmental, financial, or logistical unfeasibility. The Draft EIS discussed the final set of alternatives
that were brough forth for analysis. Each alternative was described, and the environmental and resource
impacts for each of the alternatives was thoroughly discussed. Along with the discussion of the impacts,
the impact intensity was be evaluated, and mitigation efforts were described.
The Draft EIS was available for public and agency review for 30 days to comment. Notice of review and
comment period was published on the city website at: https://www.tukwilawa.gov/departments/public-
works/construction-projects-and-transportation-impacts/allentown-truck-reroute-project/ . Public
meetings were held to inform the public of the Project, answer questions, and provide information
regarding how to comment. Public comments received during the public comment period for the Draft
EIS were reviewed, compiled, and responded to. Responses to these comments are provided as
Appendix A to this Final EIS.
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2.2.3 Final EIS Publication
The Final EIS will be available for review for 30 days following the publication of a Notice of Availability
for the Final EIS. The City will review all comments received on the Final EIS during the availability
period, and if the comments have merit, such as identifying significant new circumstances relevant to
environmental concerns from the Proposed Action or Selected Alternative, the City will determine
whether to supplement the EIS or if minor changes can be made to the existing EIS. The City will address
all comments received on the Final EIS on the ROD (Record of Decision). Following the 30-day availability
period and review of comments, a ROD will be issued. The Final EIS/ROD will cite the conclusions
regarding the environmental effects and appropriate mitigation measures for the Selected Alternative.
2.3 Document Organization
This Draft EIS is organized into four main components. Sections 1 and 2 present a summary,
introduction, and overview of the purpose, objective, issues, and potential impacts of the Project and
Alternatives.
Section 3 describes the four alternatives for the Project. Illustrations and descriptions of the three new
alternatives and the No Action Alternative are provided first. According to the State of Washing SEPA
requirements, EISs need analyze only the reasonable alternatives (WAC 197-11-402). In the
development of the alternatives for this proposed Project, several potential alternatives were presented
for, or were generated through, the scoping process. The alternatives that were removed from further
consideration are also provided in this EIS, along with a rationale as to why these alternatives were
rejected. Also in Section 3 is a discussion regarding the benefits or disadvantages of delaying the
Allentown Truck Reroute Project.
Section 4 is the largest section of the Draft EIS. This section presents the environmental analysis of each
of the affected resources that were identified as present and important for consideration for this
Project. Analysis is performed by resource, with a comparison of impacts as it pertains to each
alternative. Along with an evaluation of the impacts on each resource per alternative, proposed
mitigation measures will also be provided. Section 4 of the Draft EIS will also describe the significant
unavoidable adverse impacts that each alternative may have on each resource.
The final analytical section of the EIS, Section 5, will present the cumulative impacts. Impacts will be
discussed as they relate to present, past, and reasonably foreseeable future actions within the resource
study areas. Impacts will be defined by magnitude, and then can be compared quantitatively and
quantitatively (where possible). This comparative analysis of the cumulative impacts will assist in the
selection of a Preferred Alternative.
10
3 Piroject O o„pectilve, Piroject A teirnatilves, and No Action Alternative
3.3. Onto
The City has worked with the residents of Allentown for more than 20 years to find a truck access route
for the BNSF intermodal facility. The access route to the facility is along the southern edge of the
community and truck traffic increases commensurate with rail traffic increases.
3.2 Applicant's Project Objective
The objective of the project is to reroute existing truck traffic accessing the BNSF intermodal facility in
the Allentown neighborhood of Tukwila.
3.3 Description of the No Action Aiternative
Under the No Action Alternative, the development of an alternate trucking access route for the BNSF
South Seattle Hub would not be authorized, and the City would not conduct any construction for the
proposed Project. Modifications or improvements to the trucking route and the BNSF hub would not
occur, and activities would occur under the current operating conditions and authorizations.
In 2021, the 42nd Avenue South bridge was damaged by an oversized truck striking a bridge span, which
made the bridge unsafe for vehicular use (Lindblom 2021). As a result, the truck traffic to the BNSF
intermodal facility has been following a long-term detour. The 42nd Avenue South bridge is currently
under plan for being rebuilt, and upon its completion, truck traffic to the BNSF intermodal facility will
resume using this bridge. Truck traffic will resume travel along Interurban Avenue South, across the 42nd
Avenue South bridge, and along 42nd Avenue South and South 124th Street to the BNSF intermodal
facility. This resumed route will be the No Action Alternative, see Figure 3.3-1.
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3A Description of Project Alternatives
3.4.1 Alternative 2: Airport Way South
3.4.1.1 Feasibility Considerations of Alternative
Alternative 2 proposes a new entrance to the BNSF South Seattle Multimodal Facility -located on a
major thoroughfare and close to 1-5 on and off -ramps - which would allow freight trucks accessing the
BNSF facility to bypass the Allentown neighborhood without shifting the effects of that traffic to other
nearby areas that are similarly incompatible with freight truck traffic. As a result, Alternative 2 was
broadly supported by the public during the scoping process and was selected for analysis in the EIS.
Analysis of the Alternative 2 conceptual design prepared for the DEIS revealed several major challenges
which are detailed in this section. They include:
• The proposed entrance to the BNSF facility - on the north end of the facility, from Boeing Access
road - would require a substantial reorganization of the facility with trucking entrance and exit
functions being relocated to the area that is currently used for production.
• Avoiding conflict between these uses would entail acquiring property from the Seattle Police
Athletic Association (SPAA) - adjacent to the BNSF facility - to accommodate relocated entrance
and exit functions.
• The area in the SPAA property to which entrance and exit functions would be relocated includes
extensive steep slopes. Site preparation would require large-scale earthwork, including
excavation, hauling and disposing of substantial volumes of rock and soil, and grading.
• Earthwork -related disturbances would adversely affect several cultural resources including
structures that are part of the SPAA Historic District that are eligible for inclusion in the National
Register for Historic Places. It would also require partial removal of the rocky outcrop bordering
the BNSF facility's northwest end, which is an important part of the southern Puget Sound Salish
oral tradition and is considered culturally significant (personal communication, January 17,
2024).
• Extensive reorganization of the BNSF facility required by Alternative 2 would be a major
disruption to BNSF operations over an extended period. As a result, BNSF does not support this
alternative.
• The conceptual -level cost estimate for Alternative 2 ranges between 164 and 193 million dollars.
Even with support from state and federal grants, it is unlikely that the City of Tukwila would be
able to commit to that level of funding.
For the above -stated reasons, Alternative 2 has been determined to be unfeasible, and will not be
included for future consideration project -level planning and design. However, because of the broad
public support that Alternative 2 received during project scoping, it is being included in this EIS to
demonstrate that it has been thoroughly and accurately studied, and that analysis of this alternative
conforms with SEPA guidelines and requirements.
13
3.4.1.2 Description of the Alternative 2 Conceptual Design
The City of Tukwila is re-evaluating access to the rail operations yard at the north end of the BNSF
Intermodal Facility, see Figure 3.4-1. This alternative access would connect the northern end of the BNSF
intermodal facility to Airport Way South. A new, bi-directional two-lane roadway would be constructed
parallel to the existing railroad maintenance road that would provide ingress and egress to the BNSF
intermodal facility. A new signalized intersection would be constructed at Airport Way South and the
access road. To make this this alternative logistically practical, BNSF would need to construct the new
railroad facility entrance buildings and entrance security infrastructure at the new entrance location; the
existing facilities at the southern end of the facility would be removed. The intermodal site would need
to have additional logistical revisions made to best utilize the space and revised traffic flow patterns
entering and exiting the site. Additional properties would need to be acquired from the adjacent Seattle
Police Athletic Association (SPAA) facility to accommodate the expanded yard operations area. Plan
sheets for this alternative can be found in Appendix B, Sheet 1.
Due to geometric constraints and the alignments of Airport Way South and the new access road, access
to the BNSF intermodal facility is only feasible to and from the north at the new intersection on Airport
Way. Trucks entering the facility would do so from southbound Airport Way South, and trucks leaving
the facility would make a right turn onto northbound Airport Way South. Considering these restrictions,
circulation to access 1-5 would be via South Norfolk Street, East Marginal Way South, and South Boeing
Access Road.
The proposed access road would have a design speed of 35 miles per hour, and would include two 12-
foot-wide travel lanes (one northbound, one southbound) and five -foot -wide shoulders. The proposed
profile is designed to minimize both the amount of required earthwork and the number of vertical
curves. Four -to -one ratio (4:1) side slopes are proposed to tie into the existing ground on the western
side of the roadway, and there is a need for a retaining wall on the eastern side to mitigate the impact
on existing wetlands and existing BNSF rail tracks.
This alternative would require building a tunnel under the existing bridge on South Boeing Access Road
(see Figure 3.4-2); the exact location of tunnel will need to be determined based on further surveys in
order to avoid conflict with existing structure and to allow for future track expansion. With further
analysis and survey information, there is also a possibility of relocating this roadway to the vacant area
in front of the bridge abutment or on Boeing Access Road coupled with modifications to the structural
abutment slope. Possible road relocation for Alternative 2 is not yet verifiable at the current level of
design. Additionally, the proposed roadway profile may require cut to meet minimum vertical clearance
for the existing Sound Transit Light Rail bridge.
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This proposed alternative provides many benefits. The proposed alignment would be entirely within an
industrial area, which would result in the facility entrance being relocated out of the residential
neighborhood of Allentown. Another benefit would be the streamlined access to 1-5 for trucks to enter
and exit the facility. This option would not require any 1-5 on/off ramp realignment, and multiple bridges
would not need to be constructed.
The drawbacks of this alternative include the financial investments needed to relocate the check-
in/check-out facility, and to construct truck queuing lanes, an operations and administrative building,
chassis parking area and a truck storage access road along the western edge of the facility. This new
road and relocated facilities cannot be fully built within the existing BNSF parcel, so new rights -of -way
would be required to relocate these facilities. The area proposed for the location of these facilities is
currently the site of the Seattle Police Athletic Association firearms training facility, a historic and
popular location for both law enforcement and civilian members.
Another drawback is the cost associated with building a new tunnel under South Boeing Access Road.
Some portions of the widened access road may impact an existing wetland in the vicinity which would
also require the construction of retaining walls to mitigate that impact; remaining impacts would need
to be mitigated off -site. Further delineation of wetland boundaries would need to be completed before
environmental impacts can be confirmed.
As previously mentioned, Alternative 2 has been determined to be unfeasible, and will not be included
for future consideration project -level planning and design.
3.4.2 Alternative 3B: Improvements to 48th Place South
This alternative would connect to the southern end of the BNSF intermodal facility. A new, bi-directional
roadway would be constructed to the east of where 15th Avenue ends, extending along the BNSF
property boundary, and would cross the Duwamish River and Green River trail on a new bridge, see
Figure 3.4-3. The new roadway would connect at grade to Railroad Avenue South, and would provide
ingress and egress to the BNSF intermodal facility under the existing South 129th Street bridge. A new
signalized intersection would be constructed at the new roadway and Railroad Avenue. The railroad
facility entrance security infrastructure would be constructed at the new entrance location, existing
facilities would be removed, and their former areas would be repurposed as part of the new layout. The
intermodal site would have additional logistical revisions made to best utilize the space and would have
revised traffic flow patterns entering and exiting the site. Entrance station can be shifted further into the
yard to provide more space for trucks queuing, but it will result in further loss of capacity. Plan sheets
for this alternative can be found in Appendix B, Sheet 4.
17
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This proposed alternative provides many benefits. The proposed alignment would be completely within
an industrial area of Allentown. Truck traffic would not be traveling along residential streets; Alternative
3B would provide streamlined access to 1-5 for trucks entering and exiting the facility. Alternative 3B
would connect to the southern end of the BNSF intermodal facility which would make the cost
associated with relocation of the check in/out facility much lower and logistically more achievable.
The drawbacks of this alternative include costs associated with relocating the check-in/check-out facility,
constructing truck queuing lanes. This new road and the relocated facilities cannot be fully built within
the existing city right-of-way, so new rights -of -way would need to be acquired. Another drawback is the
cost associated with the structural components needed for this alternative, including building a new
bridge and retaining walls. Moreover, this alternative could present an impact to the river by adding a
new crossing.
3.4.3 Alternative 4: New Bridge from SR 900 (MLK Jr Way) to South 129th Street
This alternative would widen the South 129th Street bridge over 1-5 and would construct a new roadway
connecting SR 900 (Martin Luther King Junior Way) to South 129th Street. A new roadway would be
constructed on BNSF property to provide direct truck access from South 129th Street to the new check
in/check out location that would be moved to the south end of the BNSF intermodal facility. See Figure
3.4-5. To mitigate potential noise pollution, a noise wall would be installed between the new truck
access road and 51sY Place South. Truck traffic to northbound 1-5 from the South 129th Street bridge
would use the existing ramp from SR 900 (Martin Luther King Jr Way) to access the interstate. Revisions
to the exit from the 1-5 northbound/Boeing Access Road off ramp include shifting the roadway east to
accommodate a new connection to the existing southbound on ramp from the Boeing Access Road
Intersection, allowing for truck traffic to access 1-5 in both directions. The shifting of SR 900 east would
require a tall retaining wall to be constructed to support the hillside. For a detailed overview of the
proposed alternative, refer to Appendix B, Sheet 5.
The 51sY Place South roadway would have a design speed of 25 miles per hour, and would include two
12-foot-wide travel lanes and two 5-foot-wide shoulders. The widened South 129th Street bridge would
have a design speed of 35 miles per hour, and would include three 12-foot-wide travel lanes (two
uphill/southbound, one downhill/northbound), two five -foot -wide sidewalks, and curbing and gutters on
both sides of the bridge. The existing bridge profile meets the minimum clearance requirements over 1-5
and the BNSF rail lines and runs at a grade of 8% (based on lidar information available). A detail of the
southern portion of Alternative 4 is shown in Figure 3.4-6.
The proposed truck ramps from 1-5 to Boeing Access Road would have variable design speeds, as it is
anticipated that traffic will decelerate to the posted speed limits once vehicles exit the interstate. The
roadway would shift toward the east from the existing alignment by using a 713-foot radius curve with a
6% superelevated curve designed for 35 miles per hour. A left exit from the shifted roadway would
connect traffic to the existing on ramp from Boeing Access Road to 1-5; this exit would use a 134-foot
radius curve with an 8% super elevation and would have a design speed of 25 miles per hour. The outer
lane would continue towards Boeing Access Road using reverse curves to tie into the existing
intersection. Signalized intersections are proposed at the 51sY Place South/South 129th Street, South
129th Street/New Bridge, and New Bridge/SR 900 (Martin Luther King Jr Way) intersections. A detail of
the northern portion of Alternative 4 is shown in Figure 3.4-7.
20
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The proposed alternative presents several benefits including structural upgrades to the existing South
129th Street bridge and reconstructing poor condition segments. This resolves a future maintenance
/replacement issue that the City and WSDOT would need to address. It improves the connection
between SR 900 and South 129th Street, reducing congestion at the existing South 129th Street/MLK Jr
Way South intersection. This alternative provides direct on -ramps to 1-5 and moves the major truck
movements to MLK Jr Way South. The cost associated with relocating the check in/out facility will be
less in comparison to Alternative 2 since it relocates it to the southern part of the facility.
The drawbacks of this alternative include the increase of weaving traffic, especially trucks, at the SR
900/1-5 on -ramp and I-5/Boeing Access Road off -ramp. The reduction in design speed to facilitate the on
ramp could present safety or operational issues and may require a deviation approval. Given the steep
grade on the 129th Street bridge, adding a traffic signal at the bottom of the bridge may cause safety
issues, especially in inclement weather. Construction to replace a section of the existing bridge and
widen the bridge over the BNSF yard and rail lines would be disruptive to BNSF operations and would
require significant coordination.
3.5 Alternatives Removed from Further Consideration
In accordance with 40 CFR 1502.14(a), agencies are required to describe the alternatives considered but
eliminated from detailed study and to provide a brief rationale for eliminating the alternative.
Alternatives should be explored and objectively evaluated in the EIS. The Council on Environmental
Quality (CEQ) defines reasonable alternatives as 'those that are practical or feasible from the technical
and economic standpoint and using common sense, rather than simple desirable from the standpoint of
the applicant" (CEQ 1986).
Similarly, the Washington State SEPA handbook and regulations require alternatives to be considered,
and as potential alternatives are identified, they should be measures against certain criteria for viability:
1) Do they feasibly attain or approximate the proposal's objectives?; and 2) Do they provide a lower
environmental cost or decreased level of environmental degradation than the proposal? Alternatives
may be selected or eliminated based on their ability to meet the SEPA criteria.
Potential alternatives were reviewed to determine if they were consistent with the following criteria: 1)
Consistent with the Purpose and Need, 2)Technically Practical and Feasible, 3) Economically Practical
and Feasible, and 4) Environmentally Reasonable. In addition to the Preferred Alternative, as required
by regulation (40 CFR Part 1502.14 (c )), the No Action Alternative is included in the document as an
alternative carried through for full analysis. In addition, Alternatives 2, 3B, and 4 have been included as
action alternatives and have been analyzed. There were three additional alternatives that were
considered but were dismissed from detailed analysis: Alternatives 1, 3A, and 5.
3.5.1 Alternative 1: Extension of South 112th Street, East Marginal Way South to BNSF along
Utility Right -of -Way
Under this proposed alternative, South 112th Street would be extended west of East Marginal Way South
to the BNSF South Seattle Intermodal Facility. The proposed access route would be approximately one-
third of a mile long and would require a new intersection at East Marginal Way South. This route was
proposed because truck traffic would avoid driving through areas that are zoned for residential use;
traffic would be confined to 1-5 and roadways in industrial areas.
24
This alternative would create new ground disturbance within the right-of-way for Seattle Public Utilities
and Seattle City Light. While the proposed route may be short in length, the construction and operation
of this route could result in damage, outages, and significant disruptions in service for public utilities.
Utilities such as water, sewer, telecommunications, and electric are both buried and carried overhead
through this right-of-way. Daily heavy vehicle traffic could compact soils which could damage pipelines
and buried utilities, and oversized or wide -turning vehicles within a limited right-of-way could damage
poles, lines, and other infrastructures that support overhead utilities.
Because of the high potential of damage and disruption to essential public utilities, and of the potential
physical and health hazards to the community as a result of those damages or outages, this alternative
was eliminated from further consideration.
3.5.2 Alternative 3A: Gateway Drive to 48th Place South
Under this proposed alternative, truck traffic would follow a similar route described for Alternative 3B
(Section 3.3.2) except that truck traffic routed along 48th Place South, a two-lane road with businesses
and a hotel. This route was proposed because there would be a short distance between 1-5 and the BNSF
facility, and heavy vehicle traffic would travel primarily within a commercially zoned area.
This proposed access route would require the construction of widened and improved roadways, new
fencing and noise walls, and a new bridge over the Duwamish River. Large vehicles operating along this
route would have a greater presence along the popular recreation areas of Codiga Park and the Green
River Trail. The bridge approach for this proposed alternative would need to be 10 feet above the
existing grade in order to adequately clear other existing roadways and infrastructures. Large vehicles
also require a wide turning radius and would require the acquisition of new or expanded rights -of -way
or easements. Furthermore, the short distance between the southbound 1-5 off ramp and 48th Place
South would also require engineering features to create safe stopping distances for heavy vehicles.
Because of initial impact evaluation to environmental, recreation, and right-of-way resources, this
alternative was eliminated from further consideration.
3.5.3 Alternative 5: 1-5 Access
Under this proposed alternative, truck traffic would follow a similar route described for Alternative 4
(Section 3.4.3) except that a new bridge connecting South 129th Street and SR 900 would be constructed
over 1-5 and the BNSF rail yard and lines rather than being built farther to the east and the truck route
using the existing South 129th Street overpass. This route was proposed because the route would be
located primarily within highway rights -of -way, commercial or industrial -zoned areas, or within BNSF
property.
This proposed access route would require the construction of a new noise wall along Codiga Park, a new
dedicated truck access bridge connecting South 129th Street and SR 900, and new ramps along 1-5, SR
900, and from South 129th Street to the BNSF facility. The new ramps that would tie directly into 1-5
would have a sharp turning radius, thereby requiring slow speeds. Trucks entering the flow of traffic on
Interstate 5 at slow speeds would result in safety issues and congestion. The construction of ramps for
access onto SR 900 would require the acquisition of new or expanded rights -of -way or easements.
Because of initial impact evaluation to highway safety and right-of-way resources, this alternative was
eliminated from further consideration.
25
3.6 Benefits and Disadvantages of Delaying Project llimmplleimmentatlion
Washington State SEPA (WAC 197-11-440 5b(vii)) requires environmental documents to include
discussion of the benefits and disadvantages of reserving for some future time the implementation of
the proposal, as compared with possible approval at this time. The perspective of the Proponent should
be that of a trustee of the environment for succeeding generations, and particular attention should be
given to the possibility of foreclosing future options be implementing the Proposed Action.
Delaying the implementation of this project would result in the conditions described under the No
Action Alternative (Section 3.4). The benefits and disadvantages of delaying Project implementation are
presented in Table 3.6-1.
Table .3.6-1 Benefits and Disadvantages of proposed Project Implementation Delay
Resource
Financial
Noise, Air
Quality, Health
and Safety
Recreation
Plants and
Animals
Water Resources
Benefits
• The City of Tukwila will not need
to allocate expenditures for the
proposed Project at this time
• Commuters and residents will
not experience delays and noise
from construction until a later
time
• Recreational areas such as
Codiga Park and the Green River
Trail will not be impacted by
construction until a later date
• Plants and animals will not
have habitat altered and will
not be disturbed by
construction or operation.
• Depending on the route
selected, water resources in
the area will not be impacted
by potential pollution or
disturbance from construction
or operation.
26
Disadvantages
• As construction costs rise,
waiting until later to
implement the proposed
Project will result in a greater
expense
• The community of Allentown
be exposed to heavy truck
traffic, noise, and exhaust in
residential areas for a longer
period of time
• The Tukwila Community
Center will continue to
experience a high level of
heavy vehicle traffic
• Delaying the Project delays
the implementation of new
stormwater infrastructure
which could have a positive
impact on plants and animals
affected by stormwater
runoff, specifically listed fish
species.
• Delaying the Project delays
the implementation of new
stormwater infrastructure
which could have a positive
impact on water resources.
4 lrnvi r nim lnita Ana ysils
.1. Geollo /Solills
This section discusses the existing geology and soils in the study area and potential impacts resulting
from the construction and operation of Alternatives 2, 3B, 4, and the No Action Alternative.
The potential for the proposed project to result in long-term operational effects was assessed based on
geologic processes and geologic hazards that could affect slope stability, soil structure, and ground
motion. The potential for geologic hazards to alter or damage the proposed project was determined
based on the proposed project's proximity to the hazard and the existing geologic features that would
influence the relative risk.
This section also identifies proposed mitigation measures for potential impacts.
4.1.1 Affected Environment
The study area for geology and soils includes the footprint for Alternatives 2, 3B, and 4. and the general
vicinity of the No Action Alternative.
4.1.1.1 Regional Geology and Topography
The proposed Project is located within the Duwamish River valley, situated within the Puget Lowland
Geologic Province, which lies between the Cascade Mountain Range to the east and the Olympic
Mountains to the west. The area has been affected by episodic glaciation throughout the past 2.4
million years and tectonic deformation associated with the Cascadia Subduction Zone. The landscape
has been largely formed by repeated cycles of glacial scouring and deposition as well as tectonic activity.
The Puget Lowland Geologic Province has also been modified by landslides, stream erosion and
deposition, and human activity. Geologic units in the area generally consist of Quaternary glacial
deposits (Washington Department of Natural Resources [WADNR] 2024a).
4.1.1.2 Soils
4 1 1 2.1. No Action Alternative
Per the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) soil
survey map, soils in the study area for the No Action Alternative are mainly Urban Land. Per the USDA
Urban Soils Fact Sheet (2019), the term urban soil refers to soils in areas of high population density in
the largely built environment. These soils can be significantly changed human -transported materials,
human -altered materials, or minimally altered or intact "native" soils. Soils in urban areas exhibit a wide
variety of conditions and properties and may have impervious surfaces, such as buildings and pavement.
These soils are not considered prime farmland. Figure 4.1-1 includes the soils mapped within the No
Action Alternative.
4 1 1 2.2 Alternative 2.
Per the NRCS soil survey map, soils in the study area for Alternative 2 are mainly Urban Land. Figure
4.1-2 includes the soils mapped within the Alternative 2 study area.
27
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Per the NRCS soil survey map, soils in the study area for Alternative 3B are mapped as Urban Land 0 to
5-percent slopes and Urban Land-Alderwood complex, 12 to 35-percent slopes (Figure 4.1-3). None of
these soils are mapped as prime farmland.
4 1 1 2..4 Alternative 4
Per the NRCS soil survey map, soils in the study area for Alternative 4 are mapped as Alderwood-Everett-
Urban land complex, Urban land, Urban land-Alderwood complex, and Urban land Beausite complex.
None of these soils are mapped as prime farmland. Figure 4.1-4 and Figure 4.1-5 show the soils mapped
for the Alternative 4 study area.
4.1.1.3 Geologic Hazards
4 1 1 3.1. Mines
Per City of Tukwila Municipal Code (TMC) 18.06.101, mine hazards are defined as those areas directly
underlain by, adjacent to, or affected by mine workings such as adits, tunnels, drifts, or air shafts. King
County Code (KCC) defines mine hazards as an area underlain or directly affected by operative or
abandoned subsurface coal mine workings (KCC 21A.06.200). Per KCC 21A.24.205, King County utilizes
the following three classifications for Coal Mine Hazard Areas:
• Declassified coal mine areas are those areas where the risk of catastrophic collapse is not
significant and that the hazard assessment report has determined do not require special
engineering or architectural recommendations to prevent significant risks of property damage.
Declassified coal mine areas typically include, but are not limited to, areas underlain or directly
affected by coal mines at depths of more than three hundred feet as measured from the
surface.
• Moderate coal mine hazard areas are those areas that pose significant risks of property damage
that can be mitigated by implementing special engineering or architectural recommendations.
Moderate coal mine hazard areas typically include, but are not limited to, areas underlain or
directly affected by abandoned coal mine workings from a depth of zero, which is the surface of
the land, to three hundred feet or with overburden -cover -to -seam thickness ratios of less than
ten to one depending on the inclination of the seam.
• Severe coal mine hazard areas are those areas that pose a significant risk of catastrophic ground
surface collapse. Severe coal mine hazard areas typically include, but are not limited to, areas
characterized by unmitigated openings such as entries, portals, adits, mine shafts, air shafts,
timber shafts, sinkholes, improperly filled sinkholes and other areas of past or significant
probability for catastrophic ground surface collapse; or areas characterized by, overland
surfaces underlain or directly affected by abandoned coal mine workings from a depth of zero,
which is the surface of the land, to one hundred fifty feet.
No mines are mapped by the City of Tukwila (2024a), King County (2024a) or DNR (2024b) within the
study area for the Project.
33
4 1 1 3.2. Areas of potential Geologic Instabilities/Landslide Hazard Areas
Disturbances can cause mass movements of soil, rock, or debris known as landslides when slopes are
not stable. The occurrence of a landslide depends on multiple factors, including but not limited to slope
steepness, soil profile, slope shape, frequency of extreme weather events or earthquakes, and the
density of vegetation in a given area.
The City of Tukwila regulates areas of potential geologic instability. TMC 18.45.120 defines these areas
as the following:
• Class 2 are areas that have a slope between 15 percent and 40 percent and are underlain by
relatively permeable soils.
• Class 3 areas include areas sloping between 15 percent and 40 percent, which are underlain by
relatively impermeable soils or by bedrock and also include all areas sloping more steeply than
40 percent.
• Class 4 areas include sloping areas with mappable zones of groundwater seepage, and which
also include existing mappable landslide deposits regardless of slope.
The No Action Alternative transects areas mapped as both Class 2 and Class 3 landslide hazard areas
(Figure 4.1-6).
As illustrated in Figure 4.1-7, Alternative 2 transects mapped areas of both Class 2 and 3 potential
geologic instabilities near the center of the alignment and the at the southern extent of the alternative.
Alternative 3B transects mapped areas of Class 2 and 3 potential geologic instabilities near South 129th
Street and Railroad Avenue as well as where the Alternative crosses the Green River Trail (Figure 4.1-8).
Alternative 4 also transects Class 2 and Class 3 potential geologic instabilities in the portion of the
Alternative located within the City of Tukwila (Figure 4.1-9 and Figure 4.1-10).
34
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King County defines Landslide Hazard Areas as those areas at severe risk of landslide. KCC 21A.06.680
defines these areas as the following:
• An area with a combination of:
o Slopes steeper than fifteen percent of inclination
o Impermeable soils, such as silt and clay, frequently interbedded with granular soils such as
sand and gravel
o Springs or ground water seepage;
• An area that has shown movement during the Holocene epoch (10,000 years ago to the present)
or that is underlain by mass wastage debris from that epoch;
• Any area potentially unstable as a result of rapid stream incision, stream bank erosion, or
undercutting by wave action;
• An area that shows evidence of, or is at risk from, snow avalanches;
• An area located on an alluvial fan, presently or potentially subject to inundation by debris flows
or deposition of stream -transported sediments.
No landslide hazards are mapped for the portion of Alternative 4, which is the only alternative that
includes a portion of the alignment within unincorporated King County (Figure 4.1-9 and Figure 4.1-10).
The City of Seattle defines the following as landslide prone areas under Seattle Municipal Code (SMC
25.09.012 as the following:
• Known landslide areas identified by documented history, or areas that have shown significant
movement during the last 10,000 years or are underlain by mass wastage debris deposited
during this period;
• Those areas that are described as potential slide areas in "Seattle Landslide Study" (Shannon &
Wilson 2000, 2003);
• Areas with indications of past landslide activity, such as landslide headscarps and sidescarps,
hummocky terrain, areas with geologic conditions that can promote earth movement, and areas
with signs of potential landsliding, such as springs, groundwater seepage, and bowed or
backtilted trees;
• Areas with topographic expression of runout zones, such as fans and colluvial deposition at the
toes of hillsides;
• Setbacks at the top of very steep slopes or bluffs, depending on soil conditions;
• Slopes with an incline of 40 percent or more within a vertical elevation change of at least 10
feet. For the purpose of this definition, a slope is measured by establishing its toe and top and
averaging the inclination over at least 10 feet of elevation difference;
40
• Areas that would be regulated under one of subsections 25.09.012.A.3.b.2 through
25.09.012.A.3.b.5, but where the topography has been previously modified through the
provision of retaining walls or non -engineered cut and fill operations;
• Any slope area potentially unstable as a result of rapid stream incision or stream bank erosion;
• Steep slope erosion hazard areas. Steep slope erosion hazard areas are areas with a slope
described in subsection 25.09.012.A.3.b.5;
• Peat settlement -prone areas. Peat settlement -prone areas consist of Category I and Category II
peat settlement -prone areas that are delineated on Maps Al through A26, Peat Settlement -
prone Area Boundaries Maps, codified at the end of SMC Chapter 25.09.
The northern portion of Alternative 2, which is the only alternative partially located within the City of
Seattle, is not mapped as located within a landslide prone area (Figure 4.1-7).
4 1 1 3.3 Fra.sian Hazard Areas
Per TMC 18.45, the City of Tukwila does not regulate Erosion Hazard Areas as part of its critical areas
ordinance. Per SMC 25.09.12(A)(4), steep slope erosion hazards are areas with an incline of 40 percent
or more within a vertical elevation change of at least 10 feet. King County defines erosion hazard areas
as those soils in King County that may experience severe to very severe erosion when disturbed per the
1973 USDA Soil Conservation King County Soil Survey (KCC 21A.06.415). These include the following soils
when they occur on slopes of 15 percent or more:
• Alderwood gravely sandy loam
• Alderwood and Kitsap soils
• Beausite gravely sandy loam
• Kitsap silt loam
• Ovall gravely loam
• Ragnar fine sandy loam
• Ragnar-Indianola Association.
As shown on Figure 4.1-9 and Figure 4.1-10, soils subject to severe erosion located on slopes of at least
15 percent are not mapped near Alternative 4, which is the only alternative that includes a portion of
the alignment within unincorporated King County (King County 2024a). No erosion hazard areas are
mapped for the portion of Alternative 2 located within the City of Seattle (Figure 4.1-7).
4 1 1 3.4 Seismic Hazard Areas
The level of seismic hazards in the Pacific Northwest varies from low to high depending on the location
within the region, as indicated by historical seismicity, regional geological, geophysical, and tectonic
data. A discussion of the types of seismic hazards are detailed below.
4.1.1.3.4.1 Fault Rupture
Faults are features in the Earth's crust where rock periodically breaks and moves, releasing seismic
energy and creating an earthquake. The initial motion along a fault (fault rupture) causes compressional
seismic waves that release strong jolts of energy on the surface. Fault rupture can lead to structural
damage of nearby buildings, bridges, and other infrastructure. If infrastructure is located directly on top
of a fault that ruptures, damage can be significant.
41
Earthquake hazards in the Pacific Northwest are primarily related to the convergence of the North
American and Juan de Fuca tectonic plates, which forms the subduction zone known as the Cascadia
Subduction Zone, which runs along the Pacific coast shoreline from northern California to British
Columbia. This is the largest fault in Washington. Subduction of the Juan de Fuca plate below the North
American continent is capable of producing earthquakes affecting all of Washington (and the entire
Pacific Northwest). Earthquakes related to the Cascadia Subduction Zone are believed to have a
recurrence interval of between 200 and 700 years, with an average time of 535 years between
earthquakes. The last the Cascadia Subduction Zone earthquake was recorded in 1700 (DNR 2024c).
The Seattle Fault Zone is a network of shallow faults that transect the Puget Sound's lowlands from east
to west and could produce earthquakes in the upper 18 miles of the Earth's crust. As a larger shallow
fault, the Seattle Fault could produce earthquakes up to magnitude 7.5 that could last 20 to 60 seconds,
with shaking localized to the general area of the fault. The Seattle Fault last ruptured approximately
1,100 years ago. Per DNR, frequency of Seattle Fault ruptures is unknown (DNR 2024d). The Seattle Fault
is located approximately 0.53 mile north of Alternative 2.
4.1.1.3.4.2 Ground Motion/Shaking
Following an initial fault rupture, seismic waves cause shaking of the ground surface. The ground shaking
that occurs during an earthquake is generally what causes damage to overlying structures, especially
when the shaking lasts for more than a minute. Earthquake damage from ground motion at a given
location depends on the properties of the arriving seismic waves, properties of the soil at the site, and
the structures involved. The amount of ground motion that may occur during an earthquake can be
predicted based on the rock and soil properties in a given area.
Some geologic areas are more susceptible to ground shaking than others during a seismic event. The
structures of certain soils can amplify shaking and create an increased hazard. Site classes are
established and categorized by the National Earthquake Hazards Reduction Program to evaluate this
risk. Categories are defined as B through F, where site class "B" represents geologic areas that do not
dampen or amplify shaking; site classes "C-E" are areas that amplify shaking; and site class "F" are areas
that have unusual soil conditions that need to be evaluated in person. The soils in the study area for
Alternatives 2, 3B, and 4 are generally categorized as site class "D-E", suggesting they have a high
potential to amplify ground shaking during an earthquake event (DNR 2024b). Locations east of 1-5
associated with Alternative 4 are generally categorized as site class B, meaning the geologic area would
not dampen or amplify shaking.
4.1.1.3.4.3 Soil Liquefaction
Soil liquefaction can occur from shaking during a seismic event when loose, water -saturated soils, or
artificial fills behave like a liquid. Per DNR's Soil Liquefaction Susceptibility Map for King County,
Washington most of the study area for each alternative is mapped as having a moderate to high
liquefaction susceptibility (DNR 2024b), with some areas mapped as either very low or not susceptible to
liquefaction due to bed rock. Figure 4.1-11 through Figure 4.1-15 illustrate the liquefaction susceptibility
for the No Action Alternative and Alternatives 2, 3B, and 4.
42
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During a seismic event, a large amount of water can be displaced triggering a tsunami. None of the
Alternatives are mapped as being located within a tsunami inundation zone per modeling conducted for
Cascadia Subduction Zone and Seattle Fault Zone (Dolcimascolo et al. 2022a, 2022b).
4 1 1 3.5 Volcanic Hazards
Impacts to any of the Alternatives from volcanic activity could result from ashfall caused by the eruption
of Mount Rainier. Impacts from ashfall could include ash accumulation on infrastructure and suspension
of fine particles in the air. However, there is between 0.1 and 0.2 percent probability that a damaging
eruption would occur in any given year (USGS 2013). Although the impacts could be significant if an
eruption did occur, this analysis takes the probability that an impact could occur into account.
Therefore, due to the infrequency of eruptions, the probability of an impact from either ashfall or lahars
is low. None of the alternatives are mapped within a lahar inundation zone (King County 2010).
4.1.2 Relevant Plans Policies and Regulations
Relevant policies and regulations related to geology and soils are summarized in Table 4.1-1.
Table 4.1-1. Regulations and Policies for Geology and Soils
Law and Regulation
Description
State
Growth Management Act (GMA)
Requires all cities and counties in Washington to adopt
development regulations that protect critical areas,
including geologically hazardous areas.
Washington State Building Code Council
(SBCC)
The State Building Code Council was created to advise the
Legislature on building code issues and to develop the
building codes used in Washington state. These codes
help to ensure buildings and facilities constructed in the
state are safe and healthy
Local
King County Critical Areas Ordinance (King
County Code [KCC] 21A.24)
This ordinance was developed under the directives of the
GMA to designate and protect critical areas and to assist
in conserving the value of property, safeguarding the
public welfare, and providing protection for these areas.
Geologic critical areas defined in KCC 21A.24E include
volcanic, landslide, seismic, mine, and erosion hazard
areas.
48
l aw and Regulation
Description
City of Tukwila Environmentally Critical Areas
TMC 18.45
The purpose of TMC Chapter 18.45 is to protect the
environment, human life and property; to designate and
classify ecologically critical areas including but not limited
to regulated wetlands and watercourses and geologically
hazardous areas and to protect these critical areas and
their functions while also allowing for reasonable use of
public and private property. These regulations are
prepared to comply with the Growth Management Act.
Geologic critical areas as defined by TMC 18.45 include
coal mine hazard areas, areas of potential geologic
instability (areas subject to potential landslide and/or
seismic instabilities)
City of Seattle Environmentally Critical Areas
SMC 25.09
The purpose of Chapter 25.09 to provide for and promote
the health, safety and welfare of the general public, and
to not create or otherwise establish or designate any
particular person, or class, or group of persons who will
or should be especially protected or assisted by the terms
or provisions. Geologic and steep slope hazards as
defined by SMC 25.09 include landslide -prone areas, peat
settlement -prone areas, seismic hazards areas, and
volcanic hazard areas
City of Tukwila Grading TMC 16.54
Regulates grading activities including excavation, fill,
grading, earthwork construction and structural preloads.
King County Clearing and Grading
Clearing and grading permits regulate clearing and
removal of vegetation, excavation, grading and earthwork
construction within unincorporated King County.
City of Seattle Grading SMC 22.170
Regulates all grading and other land disturbing activity,
including addition and replacement of hard surface,
within the City of Seattle; to the maintenance and
protection of grades, slopes, and soil stability; and to the
correction of hazards related to any of the foregoing.
4.1.3 Methodology
The effects of alternatives on soils and geology were determined based on locations of build alternative
footprints, soil types, and topographic features. Potential impacts are discussed in qualitative terms and
are evaluated based on the definitions listed in Table 4.1-2.
Table 4.1-2. Impact Magnitude and Description
Magnitude of Impact
Description
No Impact
The project would not result in any impacts to earth/ soil resources. Geologic
hazards would not impact the project.
Minor
The project would result in short-term impacts to earth/soil resources. Geologic
hazards may result in minimal impacts the project.
Moderate
The project either would result in permanent impacts to earth/soil resources or is
at risk from a geologic hazard that have been mitigated to be less than significant.
49
Magnitude of Impact
Description
Significant
The proposed Project would result in significant permanent impacts to earth /soil
resources or be subject to geologic hazards that could cause severe damage that
cannot be mitigated for.
Impacts to the No Action Alternative were determined based on the existing infrastructure's location to
geologic hazards.
The potential for alternatives to result in long-term operational effects was assessed based on geologic
processes and geologic hazards that could affect slope stability, soil structure, and ground motion. The
potential for geologic hazards to alter or damage alternatives was determined based on the project's
proximity to the hazard and the existing geologic features that would influence the relative risk.
An unavoidable significant adverse impact would occur if regulatory requirements, design measures, or
mitigation measures would not address the potential impacts.
4.1.4 Impacts Analysis
4.1..4 1 1 Construction Dmpacts
4.1.4.1.1.1 No Action Alternative
Under the No Action Alternative, the construction of the proposed project would not occur. Existing
conditions regarding the potential for geologic hazards including earthquakes, soil liquefaction, and
volcanic hazards would continue under the No Action Alternative.
4.1.4.1.1.2 Alternatives 2, 3B, and 4
This section includes the general impacts that would be common to Alternatives 2, 3B, and 4.
Construction would result in moderate impacts from alterations to the surface geology, topography, and
soils. Soil removal, grading, and clearing necessary to complete construction of the proposed
alternatives would cause permanent alterations. Construction impacts would include short-term ground
disturbance.
Clearing and excavation during construction could result in short-term minor impacts from erosion as
bare soils become exposed to wind, rainfall, or vehicle activity within the proposed project site;
however, erosion and sediment control measures would be put in place to stabilize slopes and control
construction stormwater runoff.
The topography of the proposed project locations would be altered during construction. Because much
of the study areas have already been altered by past development, the changes from the proposed site
development and soil grading would be minor and consistent with surrounding development and would
not substantially alter the natural landscape.
Prior to construction, the City of Tukwila would be required to comply with Washington State
Department of Ecology (Ecology) Stormwater Quality Regulations by obtaining coverage under the
National Pollutant Discharge Elimination System (NPDES) through a Construction Stormwater General
Permit to help control runoff and reduce water pollution from the construction site. The City would be
required to develop a Stormwater Pollution Prevention Plan (SWPPP) (in conformance with
50
requirements in the City of Tukwila Stormwater Management Program Plan and the Infrastructure
Design and Construction Standards, the King County Surface Water Design Manual and City of Seattle
Stormwater Manual), implement sediment erosion and pollution prevention control measures, and
receive an approved permit under the NPDES program.
Construction of the Project would result in permanent impacts from alterations to the surface geology,
topography, and soils. Impacts would be moderate with the implementation of mitigation measures
listed in Section 4.1.4.
4.1..4.1..2. Operations Dmpacts
4.1.4.1.2.1 No Action Alternative
Under the No Action Alternative, the BNSF truck route would continue operating under current
conditions and no impacts to earth or soil resources would occur. Existing conditions regarding the
potential for geologic hazards including earthquakes and soil liquefaction would continue under the No
Action Alternative, resulting in the potential for moderate impacts from a seismic event. Ashfall
associated with an eruption of Mount Rainier could result in minor impacts to the existing operating
conditions.
4.1.4.1.2.2 Alternatives 2, 3B, and 4
Following construction, additional impervious surfaces may increase the amount of stormwater runoff
generated in the selected project area, leading to the increased potential of erosion of receiving water
bodies. No additional excavation or disturbance of ground surfaces would be required during the
operation of the Project. Therefore, no additional impacts to geology or soils are anticipated from the
Project.
4.1.4.1.2.3 Impacts from Geologic Hazards
The alternatives would not alter the risk of geologic hazards in the study area, but these hazards could
affect construction and operation of the proposed Project. Hazards that could occur during construction
and operation include an earthquake resulting in ground motion/shaking or soil liquefaction, and
volcanic hazards. These hazards are discussed below.
4.1.4.1.2.3.1 Volcanic Hazards
As discussed in Section 4.1.1.3.5, impacts on the proposed Project from volcanic activity could result
from ashfall caused by the eruption of Mount Rainier. None of the alternatives are mapped within the
modeled lahar inundation zone associated with Mount Rainier; therefore, no impacts from lahars are
anticipated. Therefore, minor impacts are anticipated from volcanic hazards.
4.1.4.1.2.3.2 Areas of Potential Geologic Instabilities/Landslides
As noted above, all build alternatives transect mapped areas of City of Tukwila Class 2 and 3 areas of
potential geologic instabilities and may requiring slope stabilization. Per TMC 18.45.130, development
within a Class 2 or 3 area requires a geotechnical report prepared by a qualified geotechnical engineer
showing that either there is no evidence of past instability in vicinity of the proposed development, that
areas of potential geologic instability can be modified, or the Project can be designed so that any
potential impact to the Project or surrounding properties can be eliminated. The City would implement
appropriate slope stabilization measures determined during design, per the requirements of TMC 18.45.
In addition, clearing and grading activities would be subject to a stormwater water quality and quantity
51
control plan, including preparation of temporary erosion and sediment control plans, and drainage plans
per TMC 18.45.130(C)(4).
Therefore, minor impacts from areas of potential geologic instabilities or landslides are anticipated.
4.1.4.1.2.3.3 Seismic Hazards
There is the potential for earthquakes to occur in the study area. Prolonged earthquake -related ground
shaking has the potential to disrupt construction activities and damage buildings and utilities. The
potential for ground motion to damage infrastructure depends on the type and strength of seismic
motion and the ground/soil conditions. Some soils in the study area for each alternative are mapped as
having a moderate -to -high susceptibility for liquefaction in the event of an earthquake, and liquefaction -
induced settlement may occur during a strong seismic event. Seismic design parameters would be
incorporated into the design of the Project to minimize potential damage in conformance with the
standards set forth in in the Washington State Building Code, Seattle Building Code, and the King County
Building Code. If these design standards are implemented, the risk of severe structural damage or failure
of Project infrastructure from shaking as a result of ground motion associated with earthquakes from
the Cascadia Subduction Zone or the Seattle fault would be minimized. However, risk is never
eliminated, irrespective of design, and is considered a moderate impact to the Project.
4.1.4.1.2.3.4 Mines
No impacts are anticipated because no mines are mapped within the study area for any of the build
alternatives.
4.1.5 Mitigation Measures
Below is a description of the mitigation measures that would be available to minimize or avoid impacts
to geology and soils from construction and operations of the proposed Project. Mitigation measures
would be common to Alternatives 2, 3B, and 4.
4.1.5.1 Construction Impacts Mitigation
Construction would impact surface geology, topography, and soils. Soil removal, grading, and clearing
necessary to complete construction of the project would cause permanent alterations. The mitigation
measures described below would minimize the construction -related impacts.
• Soil erosion shall be minimized to the maximum extent possible through
implementation/incorporation of all applicable Best Management Practices (BMPs) during
construction and may include the following:
o The City shall implement a Construction Stormwater Pollution Prevention Plan (SWPPP) that
will satisfy the requirements of the National Pollutant Discharge Elimination System General
Permit for Stormwater Discharges Associated with Construction Activities.
o The Construction SWPPP will include measures for temporary erosion and sedimentation
control and would identify a regular inspection and maintenance schedule for all erosion
control structures. The SWPPP shall include descriptions of all BMPs to be implemented
during construction to minimize erosion and sediment entering surface waters.
52
o Erosion and sedimentation control measures shall be implemented at the beginning of the
construction process and maintained throughout all phases of construction. Measures may
include, but are not limited to, installation of a stabilized construction entrance, a wheel
wash, silt fences, seeding, mulching, and dust control, and all other BMPs as recommended
by a licensed civil engineer.
o Additional erosion control supplies, including sandbags and channel -lining materials, shall be
stored on -site for emergency use.
o The project area shall be monitored for erosion on a weekly basis and after large rainfall
events, and corrective action would be taken as needed. Soil stockpiles shall be stabilized
and protected from erosion and soils shall also be stabilized before a holiday or weekend if
needed, based on forecasts of precipitation.
• Site planning shall implement low impact development principles to the maximum extent
feasible in order to minimize impacts to soils and geological resources.
4.1.5.2 Operational Impacts Mitigation
During operation, no additional excavation or disturbance of ground surfaces would be required.
However, additional impervious surfaces would increase the amount of stormwater runoff generated,
leading to the increased potential of erosion of receiving water bodies. Additionally, sources of runoff
discharged from the site through storm water conveyance systems could cause erosion or earth
movement if inappropriately designed or placed. However, all stormwater systems would be designed in
accordance with Tukwila Stormwater Management Program Plan and the Infrastructure Design and
Construction Standards, as well as the King County Surface Water Design Manual and Seattle
Stormwater Manual. Therefore, the impact to soils and geology during operations is considered
moderate.
4.1.5.3 Mitigation Measures Related to Geologic Hazards
Hazards that could occur during construction and operation include an earthquake resulting in ground
motion/shaking or soil liquefaction, erosion and sedimentation hazards, geologic instability, and volcanic
hazards. The mitigation measures described below would minimize the impacts related to geologic
hazards identified in the impacts analysis. The proposed Project designs shall include all reasonable
measures to reduce the risk of damage from geologic hazards present in the proposed Project area.
These measures would be in accordance with City of Tukwila, City of Seattle, and King County critical
areas ordinance and building code, as well as the specific geologic requirements of the site.
Site planning principles shall acknowledge and account for the risks associated with seismic risks and
areas of potential geologic instabilities. During site development permitting, the City shall provide a
written geological hazards narrative from a qualified engineer demonstrating to the satisfaction of the
City of Tukwila, City of Seattle, and King County, that all efforts are made to avoid, minimize, and reduce
geological hazard impacts to the site development and implementation of all BMPs and compliance with
mitigation described and outlined herein.
The following BMPs would be instituted to mitigate seismic and geologic instability hazards:
53
1. An emergency management plan shall be put in place during construction for use in the event of
an earthquake.
2. A geotechnical engineer licensed in Washington State shall be retained to review and approve
plans prior to construction to assist in reducing liquefaction risks from and to the Project. The
licensed engineer of record shall determine the appropriate foundation, footing, and structural
design to conform to the International Building Code standards for seismic protection.
3. A geotechnical engineer licensed in Washington State shall be retained to conduct detailed
slope stability evaluations for the Project, including the development and use of slope
stabilization methods to be utilized and may include retaining walls or slope stabilization.
4.1.6 Significant Unavoidable Adverse Impacts
The construction and operation of the Project would not result in any unavoidable adverse impacts on
earth resources. Permanent changes to the geology at the Project site would result from the
construction of the proposed project. These changes would be limited to the soil and underlying
sediment in the areas of construction where excavation, fill, and soil amendments would be needed to
meet design requirements.
If a major earthquake were to occur near the project area, unavoidable adverse impacts could result
from the liquefaction of susceptible soils underlying elements of the Project. However, the Project
would comply with City of Tukwila, City of Seattle, and King County regulatory requirements (building
codes, engineering best practices for temporary sedimentation and erosion control and compliance with
Critical Area Ordinances) site -specific geotechnical assessment, implementation of stormwater controls,
and design and implementation of site -specific BMPs to minimize and mitigate adverse impacts on earth
resources or resulting from geological processes. With the implementation of these mitigation
measures, the impacts on earth resources would be reduced to a level of non -significance.
54
4.2 Water Resources (Fboodpbab s, Wetlands, Water Quabbty, Surface Water,
Groundwater)
Water is a beneficial resource essential to agriculture, industry, recreation, and human and ecological
health. Water resources are typically subdivided into two types: surface water and groundwater. Surface
water resources area essential to maintaining human health, fish and wildlife habitat, and vegetation.
Groundwater resources serve as the underground storage of fresh water that can be used for drinking,
irrigation, recharge areas, and general water supply. Floodplains are related water resource areas where
surface water inundates low-lying groundwater during flood events. Floodplains provide essential
habitat for wildlife, act as sedimentation and filtering areas for improving water quality and
groundwater recharge, and protect communities against flooding and erosion.
The objective of the Allentown Truck Reroute Project (Project) is to develop an alternative route to the
BNSF Intermodal Facility in the Allentown neighborhood located in Tukwila, Washington. The Project will
improve livability and safety in Allentown without compromising the operations of the BNSF intermodal
facility. There are four alternatives considered within the study area (No Action Alternative, Alternative
2, Alternative 3B, and Alternative 4). The existing truck route, which is the No Action Alternative, in
addition to three proposed route alternatives will be analyzed in this section to determine potential
impacts on water resources (Figure 4.2-1). Additional details regarding the Project description and
proposed alternatives can be found in Section 1 and Section 2.
55
.5
4.2.1 Affected Environment
The affected environment section describes the existing water resources in the study areas of the No
Action Alternative, Alternative 2, Alternative 3B, and Alternative 4. Water Resources include floodplains,
surface waters (wetlands, streams, rivers, lakes, and ponds), water quality, and groundwater.
4.2.1.1 Regional Hydrology
The City of Tukwila is located in the Green-Duwamish Watershed. According to Tukwila Municipal Code
(TMC) 14.30.030, a watershed is defined as the "geographic region within which water drains into a
particular river, stream, or water body (waterbody defined as a creek, stream, pond, wetland, lake or
river) and is numbered by the State of Washington Water Resource Inventory Area (WRIA) as defined in
the Washington Administrative Code."
The City of Tukwila is divided into nine drainage basins. The study area of the proposed Project is
located within the Green/Duwamish River Mainstem drainage basin. All surface water identified within
the proposed Project area drains into the Green-Duwamish River (CHM2Hill 2013).
The Green-Duwamish Watershed is divided into four subwatersheds, with the City of Tukwila straddling
two: the Lower Green River subwatershed and the Duwamish Estuary subwatershed. The proposed
Project vicinity is located entirely within the Duwamish Estuary subwatershed, and is located near the
boundary of the two subwatersheds. All surface and ground water within the Green-Duwamish
Watershed comes from either precipitation as rain or snowmelt (Ecology 1995).
The headwaters of the Green-Duwamish River are located in the Cascade Mountains, where the river
travels northwest for 93 miles before emptying into Elliot Bay (Herrera 2005; Kerwin and Nelson 2000).
The Green-Duwamish River is the largest freshwater component in the WRIA 9 (Ecology 2022a). The
river is known as the Green River from river mile (RM) 93 to RM 10, and as the Duwamish River from RM
10 until it reaches Elliot Bay. The Duwamish River flows along the western and southern boundary of the
study area; the general Project vicinity is located between RM 5.6 and RM 9. Historically, three major
tributaries fed the Green-Duwamish River: the White River, the Cedar River, and the Black River. These
three rivers have been rechanneled out of the Green-Duwamish River over the last 120 years, reducing
the normal river flow of the Green-Duwamish River by a third (KCBR 2008).
The Duwamish River valley, which includes the study area, is less than 20 feet above sea level and is
prone to flooding during high tides, extreme rainfall, and high streamflow (WWSC 2023). In a typical
year, the study area receives approximately 32 to 38 inches of precipitation (CHM2Hill 2013), primarily
in the form of rainfall in the winter months (Ecology 2022a).
4.2.1.2 Floodplains
The study area for floodplains and water quality includes the Duwamish River and its floodplain. The
geography and topography of Tukwila is heavily influenced by the Green-Duwamish River and its
associated floodplains (CHM2Hill 2013). The Project vicinity is dominated by steep valley walls along the
1-5 corridor and relatively flat and poorly drained floodplains adjacent to the river. Tukwila Municipal
Code (TMC) 16.51.030 defines a floodplain as "any land area susceptible to being inundated by water
from any source." Flooding is generally considered temporary in condition and may include partial or
57
complete inundation of normally dry land. Sources of flooding include the overflow of inland or tidal
waters, the unusual and rapid accumulation of surface waters, mudslides, the collapse of land into a
body of water, and abnormal tidal surges (TMC 16.51.030).
The Project vicinity is located east/northeast of the Duwamish River between RM 5.6 and RM 9 (Figure
4.2-1). The Duwamish River has been extensively channelized and diked. Within the proposed Project
vicinity, there are several levees and revetments. Levees prevent flooding to surrounding areas and
revetments protect the riverbanks from impact.
The Federal Emergency Management Agency (FEMA) manages flood maps and risk assessments under
the National Flood Insurance Program (NFIP). The NFIP prohibits development that encroaches the
regulatory floodway unless it can be proven that the 100-year flood level will not increase. A No -Rise
Certification must be documented through both hydrologic and hydraulic analyses. Flood Insurance Rate
Maps (FIRM) are the official map of a community on which special flood hazard areas (SFHA) have been
delineated (TMC 16.51.030). SFHAs are within the 100-year floodplain, meaning there is a 1% chance of
a flood event occurring. SFHAs are indicated on FIRMs as zone A, AO, AH, A1-30, AE, A99, AR (V, VO, V1-
30, VE). The SFHAs were reviewed to determine the presence of floodplains in the Project vicinity
(Figure 4.2-2). The study area is located within FEMA FIRMs 53033C0645G, 53033C0957G, and
53033C0960G.
The Duwamish River is classified as a regulatory floodway (Zone AE). Development in Zone AE requires a
Floodplain Development Permit because projects located in floodplains are at risk for increased
frequency and severity of flooding caused by obstruction of flood flows or filled floodplain storage
(WSDOT 2024a).
58
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4. 2.1.3 Surface Waters
According to TMC 14.30, surface waters are "the portion of precipitation that does not naturally
percolate into the ground or evaporate, but flows via overland flow, interflow channels, or pipes into a
natural drainage system, a surface water conveyance system, or into a constructed surface water
facility." Tukwila's wetlands have been defined using the Washington State definition [RCW
36.70A.030(48)] and Tukwila's watercourse classifications are consistent with the Washington State
Department of Natural Resources (DNR)'s stream typing system.
Surface waters generally include wetlands, streams, rivers, lakes, and ponds. Twelve wetlands (Wetlands
1 to 12; Table 4.2-1) and two streams (Duwamish River and Stream 1; Table 4.2-2) are found within the
study area (Figure 4.2-3). There are no lakes or ponds. HDR prepared a technical memorandum, Wetland
and Streams Technical Memorandum (Appendix C) that identified and documented existing wetlands
and streams along and near the existing truck route, the No Action Alternative, and Alternatives 2, 3B,
and 4. The wetland and stream study objectives, study area, methods, regulatory requirements, and
findings are included in the Technical Memorandum. Wetland rating forms and site photographs are
included in the Technical Memorandum in Attachments A and B, respectively. The following subsection
discusses the hydrologic and hydraulic features of wetlands and streams. Additional information
regarding wetlands and streams in or near plant and animal habitat can be found in Section 4.3 Plants
and Animals.
4.213.1. Wetlands
The study area for wetlands encompasses the area within 300 feet of the edges of the long-term
proposed Project footprint, which is defined as the physical footprint of the truck access routes that
would result in permanent impacts on wetlands. This distance was selected to match the typical largest
applicable potential buffer width for wetlands within the City of Tukwila, the City of Seattle, and
unincorporated King County. Wetlands evaluated in this EIS include wetlands that are wholly or partly
within the study area.
60
5 ;5
5 5
00
According to TMC 18.06.922, a wetland is an "area that is inundated or saturated by groundwater or
surface water at a frequency and duration sufficient to support, and that under normal circumstances
do support, a prevalence of vegetation typically adapted for life in saturated soil conditions." While
wetlands include natural features such as bogs, swamps, marshes, ponds, lakes, and similar areas, they
do not include artificial wetlands intentionally created from upland sites including irrigation and
drainage ditches, grass -lined swales, canals, detention facilities, wastewater treatment facilities, farm
ponds, landscape amenities, or wetlands created after July 1, 1990, that were unintentionally created as
a result of the construction of a road, street, or highway. Artificial wetlands intentionally created from
non -wetland areas as a form of wetland mitigation as permitted by the City shall be considered
wetlands (TMC 18.06.922).
Qualified HDR biologists conducted the wetland and stream field reconnaissance for the study area on
May 22, 2024. Biologists documented and recorded vegetation, soil, and hydrology conditions as
necessary at representative wetland and upland areas using methods outlined in the Corps of Engineers
Wetlands Delineation Manual (Environmental Laboratory 1987 in Appendix C) and the Regional
Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and
Coast Region Version 2.0 (USACE 2010 in Appendix C). Each wetland identified in the study area received
a unique identifier that was tracked in a geographic information system (GIS) database. Estimated
wetland boundaries that were documented at sites accessed during the field reconnaissance were
mapped in the field using a global positioning system (GPS). Wetlands that were not accessible during
field reconnaissance surveys were mapped based on documentation and surveys from other projects or
sources, field observation, aerial imagery, and best professional judgement.
Following the field reconnaissance, all wetlands identified in the study area were rated and the
hydrogeomorphic (HGM) (Brinson 1993) classification was determined using the Washington State
Wetland Rating System for Western Washington — 2014 Update Version 2.0 (Hruby and Yahnke 2023).
Wetland habitats in the study area were classified using the system outlined by the USFWS in
Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al. 1979; FGDC
2013), typically referred to as the Cowardin system. The Cowardin system classifies wetlands based on
the dominant vegetation structure and water regime.
62
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4.2.1.3.1.1 Wetlands Descriptions
Wetland 1 is a narrow tidal fringe wetland located on the east bank of the Duwamish River. NWI maps
the Duwamish River as a permanently flooded tidal riverine wetland with an unconsolidated bottom
(USFWS 2024 in Appendix C). Wetlands 1 and 8 are contiguous on both banks of the Duwamish River
and are separated by an unvegetated channel wider than 50 feet, so these wetlands were treated as
separate wetland rating units and received unique identifiers. Wetland 1 was determined to be a
Category II wetland that met estuarine special characteristics.
Wetland 2 is a tidal fringe wetland located within Codiga Park. This wetland is not mapped by NWI, the
City of Tukwila, or King County, but it is a partially -restored wetland that has been improved through
channel modification, wetland plantings, riparian habitat plantings, and habitat installations (USFWS
2024; City of Tukwila 2024; and King County 2024 in Appendix C). The City of Tukwila (2024) maps this
area as below the OHWM of the Duwamish River. Wetland 2 was determined to be a Category I wetland
that met estuarine special characteristics.
Wetland 3 is a depressional wetland that is located in a low spot between two BNSF operations yard
storage areas and north of South 129th Street. This wetland is not mapped by NWI, City of Tukwila, or
King County, but it was observed from the South 129th Street elevated street surface (City of Tukwila
2024, King County 2024, USFWS 2024 in Appendix C). This wetland is largely supported by high
groundwater and surface runoff from the surrounding developments and is located where the City of
Tukwila (2024) maps a Type Ns stream. The wetland drains from the north to the south, and a culvert
outlet was observed that discharges directly to the Duwamish River approximately 110 feet to the
south. Wetland 3 was determined to be a Category II wetland with high water quality and hydrologic
functions.
Wetland 4a is a depressional wetland bordered by road and railroad prisms and a steep hillslope. The
wetland was observed to be deeply ponded with areas of open water and was assumed to have no
outlet. Wetland 4 was determined to be a Category II wetland with high water quality and hydrologic
functions.
Wetland 4b is a depressional wetland bordered by road and railroad prisms and a steep hillslope. The
wetland was observed to be deeply ponded with areas of open water and was assumed to have no
outlet. Wetland 4 was determined to be a Category III wetland with high water quality and hydrologic
functions.
Wetland 5 is a depressional wetland that is in a topographic depression bordered by Airport Way South,
South Boeing Access Road, and the BNSF operations yard. The wetland was observed to be deeply
ponded with areas of open water. No outlet was observed; however, an outlet was assumed based on
the stream that was mapped by USGS and DNR which drains this wetland area to the Duwamish River
approximately 1,200 feet to the west (DNR 2024a). There was no evidence of a bed or bank within
Wetland 5. Wetland 5 was determined to be a Category II wetland with high water quality and
hydrologic functions
Wetland 6 is a depressional wetland located on the City of Seattle Finance and Administrative Services
property. It was not observed in the field , but based on a previous delineation (Watershed 2023 in
Appendix C), it is vegetated by facultative grasses. Wetland 6 was determined to be a Category III
wetland with moderate water quality and hydrologic functions.
64
Wetland 7 is a depressional wetland located on the Seattle City Light transmission ROW. It was not
observed in the field, but it was delineated by Watershed (Watershed 2023 in Appendix C) and is
mapped by the city of Tukwila. Aerial imagery shows construction activities and the placement of fill
material within Wetland 7 in 2013, with potential compensatory mitigation occurring in 2017. Surface
water appears to extend off site under mature trees adjacent to the BNSF operations yard. There is no
assumed outlet as determined by using available topography. Wetland 7 was determined to be a
Category II wetland with high water quality and hydrologic functions.
Wetland 8 is a narrow tidal fringe wetland located on the east bank of the Duwamish River. NWI maps
the Duwamish River as a permanently flooded tidal riverine wetland with an unconsolidated bottom
(USFWS 2024 in Appendix C). It is similar to, and shares the same description and functions as, Wetland
1. Wetlands 1 and 8 are contiguous on both banks of the Duwamish River and are separated by an
unvegetated channel greater than 50 feet. Wetland 8 was determined to be a Category II wetland that
met estuarine special characteristics
Wetland 9 is a depressional wetland and is assumed to be hydrologically connected to Wetland 5.
Wetland 9 is separated from the Project and Wetland 5 by the approximately 200-foot-wide BNSF
operations yard. No outlet was observed; however, an outlet was assumed based on the stream
mapped by USGS and DNR that drains this wetland area to Wetland 5 and eventually Duwamish River
(DNR 2024a). There was no evidence of a bed or bank within Wetland 9. Wetland 9 was determined to
be a Category II wetland with high water quality and hydrologic functions.
Wetland 10 is a large slope and depressional wetland with some riverine components that is located
within a drainage that slopes from the northeast to the southwest toward 1-5. An overhead utility line
and service road is also located within the drainage. This wetland was delineated by Wet.Iand (2022)
and is mapped by the City of Tukwila (City of Tukwila 2024 in Appendix C) but is not mapped by NWI,
King County, or WDFW (USFWS 2024, King County 2024; WDFW 2024b in Appendix C). Surface water
near the bottom of the drainage was observed adjacent to 1-5 road prism. Based on this observation,
scientists assume that there is no outlet or hydric soils. Wetland 10 was determined to be a Category III
wetland with moderate water quality and hydrologic functions.
Wetland 11 is a small slope wetland that is located to the south of Stream 1 and Wetlands 12a and 12b.
This wetland was estimated by Wet.Iand (2022), but is not mapped by NWI, King County, or WDFW
(USFWS 2024, King County 2024, WDFW 2024b in Appendix C). Wetland 11 is hydrologically supported
by a high groundwater table. It was determined to be a Category III wetland with moderate water
quality and hydrologic functions.
Wetland 12a is a riverine wetland associated with Stream 1, a Type Np water. This wetland was
delineated by Wet.Iand, but is not mapped by NWI, King County, or WDFW (USFWS 2024, King County
2024, WDFW 2024b in Appendix C). Wetland 12a is mapped within a ravine that slopes from the east to
west. Wetland 12a was determined to be a Category II wetland with high water quality and moderate
hydrologic functions.
Wetland 12b is a riverine wetland associated with Stream 1, a Type Np water. This wetland was
delineated by Wet.Iand, but is not mapped by NWI, King County, or WDFW (USFWS 2024, King County
2024, WDFW 2024b in Appendix C). Wetland 12b is mapped within a ravine that slopes from the east to
65
west. Wetland 12b was determined to be a Category II wetland with high water quality and moderate
hydrologic functions.
4.11 3.1. Streams
Streams are referred to as waterbodies and aquatic areas by the City of Tukwila and the unincorporated
County, and as fish and wildlife habitat conservation areas (FWHCAs) by the City of Seattle. The study
area of streams encompasses the area within 200 feet of the edges of the long-term Project footprint.
This distance was selected to match the largest applicable potential buffer width for streams within the
City of Seattle and unincorporated County and to match the buffer for shorelines and streams within the
City of Tukwila. Streams evaluated in this EIS include streams that are wholly or partly within the study
area.
A stream is defined by the U.S. Army Corps of Engineers (USACE) as, "A body of water flowing in a
definite natural or manmade course that has the potential to flood. The term 'stream' refers to rivers,
streams, creeks, brooks, etc., and includes intermittent streams that are subject to flooding."
Table 4.2-2 Summary of Streams within the Study Area
Stream
Na me
Duwamish
River
Stream 1
WAC 222-16-030
'TMC 18.44.040
TMC 18.45.100.0
Water Type' Jurisdiction
Ci
Buffer width (feet)
.y°ofTukwila 50b (Shoreline Residential)/
100b (Urban Conservancy withou
City of Tukwila
Levees)
..............................................................................:..........................................:.............................................
100c
Design Alternative
with Potential Direct
or Buffer Impacts
NAA, 3B, 4
4.2.1.4 Water Quality
Per TMC 14.30, and as outlined in the 2024 Tukwila Stormwater Management Program, the City of
Tukwila adopted the Washington Department of Ecology (Ecology) approved 2021 King County
Stormwater Pollution Prevention Manual (KCSPPM) in 2022. The KCSPPM complies with the
requirements of the Federal Clean Water Act- National Pollutant Discharge Elimination System (NPDES)
Program and the State Puget Sound Water Quality Management Plan-Stormwater Program (KCSPPM
2021).
Water quality standards exist to protect surface water and groundwater quality for their designated
uses by providing minimum requirements for reducing and controlling the discharge of contaminants
(KCC 9.12.005). Water quality criteria may be numeric or narrative and addresses standards for
pollutants such as oils, greases, and fuels; metals; sediments; oxygen -demanding substances; nutrients;
toxic organic compounds; fecal bacteria levels; and pH (KCSPPM 2021). In 2003, water use -based
classification for state surface waters were adopted by Ecology that determined the water quality
standards applicable for that water body (RCW 173-201A-600(1)). The Duwamish River was classified as
Salmonid Rearing/ Migration Only and Second Contact Recreation.
The Duwamish River is listed as a Clean Water Act (CWA) Section 303(d) Category 5, impaired waterbody
(EPA n.d.) for 10 different parameters including temperature, pH, polychlorinated biphenyls (PCBs), and
66
other industrial pollutants (Table 4.2-3; EPA n.d.; Ecology 2024a). The Duwamish River has an approved
Total Maximum Daily Load (TMDL) for Ammonia (Ecology 2024b). In 2001, the U.S. EPA declared the
lower five miles of the Duwamish River a Superfund site; however, the Superfund site is located
downriver from, and completely outside of, the proposed Project vicinity. Contaminated sites within the
Project vicinity are discussed in Section 4.7 Health and Safety.
Table 4.2-.3 Duwamish River Section .30.3(d) Category 5 parameters
Parameter
Testing Medium
Temperature
Water
pH
Water
Bacteria - Fecal coliform
Water
4,4'-DDT
Tissue
4,4'-DDD
Tissue
4,4-DDE
Tissue
Alpha-BHC
Tissue
Polychlorinated biphenyls (PCBs)
Tissue
Bacteria — Escherichia coli
Water
Mercury
Water
The Duwamish River faces nine identified surface water issues involving drainage, water quality, and
aquatic habitat (Table 4.2-4; CH2M Hill 2013). The primary cause of drainage issues arises from lack of
storm drainage systems, damaged or poorly maintained conveyance systems, and inadequate hydraulic
capacity of conveyance systems. Numerous NPDES-permitted outfalls drain into the Duwamish River
with close proximity to the Project vicinity (Figure 4.2-3). Water quality issues are caused by untreated
runoff from arterial streets with intensive traffic usage, areas of dense commercial development,
parking lots in the Tukwila International Boulevard corridor and Westfield Mall area, and Interstates 5
and 405. the primary cause for the reduction in aquatic habitat development and loss of riparian buffer
areas is. There are nine identified locations of surface water issues (Figure 4.2-4); however, they issues
do not coincide with the footprints of any of the alternatives for this proposed Project.
Table 4.2-4 Surface water issues in Tukwila affecting the Duwamish River
ID
Issue Type
Problem Description
Location
1
Water
quality
Outfalls discharge directly to receiving
water, no treatment
All outfalls are potential candidates; 48th Ave
S and S 122nd are two top candidates
2
Drainage
Ponding in low spot, possible ponding on
the east side of road
49th Ave S and S Hazel Street
3
Water
quality
Dumping
S 114th St and 49th Ave S
4
Habitat
Lack of off -channel salmon habitat along
lower Duwamish
Duwamish River near light rail crossing
5
Drainage
E Marginal Way S Stormwater Outfall
North end of Tukwila, along east shore of
Duwamish River; 4 outfalls proximate to S
87th Place
6
Water
quality
Duwamish River riverbank at S 104th St is
eroding, causing failure of road shoulder
and habitat degradation
Duwamish River right (east) bank at S. 104th
St
67
ID
Issue Type
Problem Description
Location
7
Water
quality
Duwamish River riverbank at S 115th St is
eroding, causing failure of road shoulder
and habitat degradation
Duwamish River right (east) bank adjacent to
S 115th St between 42nd Ave S and E
Marginal Way S and adjacent to 42nd Ave S
from S 115 St to Interurban Ave S.
8
Drainage
53rd Ave S storm drain system has
inadequate capacity
53rd Ave S near S 139th
9
Drainage
S 143rd St has no drainage system
S 143rd St, east of Interurban Ave; S 144th St,
S 143rd Place, S 143rd S, east of Interurban
Ave S between Interurban and Duwamish
River, W. of Duwamish, near Black River
convergence
Source: Appendix DTable D-1 in CH2MHill 2013
Pollution -generating surfaces are considered a significant source of pollutants in stormwater runoff and
include both pervious and impervious surfaces. The Washington Administrative Code (WAC) 173-218-
030 describes pollution -generating surfaces as including surfaces that involve regular vehicle use or
industrial activities like those found in the Project study areas. Pollution generating surfaces that are
relevant to the Project include roads, unvegetated road shoulders, bike lanes within the traveled lane of
a roadway, driveways, parking lots, and vehicular equipment storage yards.
Stormwater runoff from pollution -generating impervious surfaces (PGIS) has the potential to affect fish
species, degrade habitat, and decrease water quality. An increase in PGIS potentially increases
stormwater runoff rates, volume, and pollutant loads because PGIS do not absorb stormwater runoff.
Trash, chemicals, dirt, sediment, and other harmful pollutants can be transported through stormwater
runoff events (EPA n.d.).
68
Lu Ff, 0 H 1-- rr
1
4.2.1.5 Groundwater
The study area for groundwater includes the footprint for Alternatives 2, 3B, and 4, and the general
vicinity of the No Action Alternative. According to KCC 9.04.020, groundwater is defined as "all water
found in the soil and stratum beneath the land surface or beneath the bed of any surface water."
Susceptibility to ground water contamination occurs where there is a combination of permeable soils,
permeable subsurface geology, and ground water close to the ground surface. Groundwater direction
and flow are not well understood in the Project vicinity (Senter et al. 2020).
The King County Groundwater Well Viewer database and the Ecology Well Construction and Licensing
database were reviewed for potential wells in the Project vicinity. Wells collect various data about
groundwater including but not limited to levels and flow conditions. No wells were identified within the
Alternative footprints (KCGWV n.d.; Ecology n.d.a).
The EPA Sole Source Aquifer (SSA) and King County Critical Aquifer Recharge Area (CARA) GIS layers
were used to determine if there were any SSAs or CARAs near the Project vicinity (SSA n.d.; CARA n.d.).
An SSA is designated by the EPA as the sole or principal source of drinking water for an area. According
to KCC 21A.06.253C, a CARA is an area that has a high susceptibility to groundwater contamination or an
area of medium susceptibility to ground water contamination that is located within an SSA. A CARA may
also be considered a wellhead protection area for a municipal or district drinking water system (246-290
WAC). The databases indicated that there were no SSAs or CARAs within the Project vicinity. The
Washington State Department of Ecology (Ecology) Groundwater Map Search was used to determine if
there were any wellhead protection zones or other areas of importance within the Project vicinity. The
Ecology Groundwater Map Search database did not identify any wellhead protection zones or areas of
importance (Ecology n.d.b).
4.2.2 Relevant Plans Policies and Regulations
The relevant plans, policies, regulations, and guidance consulted when analyzing the potential impacts
of the proposed Alternatives are described in Table 4.2-5.
Table 4.2-5 Relevant Plans, Policies, and Regulations
Law and Regulation
Description
Federal
Sections 10, 303, 401, 404, and 408 of the
Clean Water Act
Required for projects proposing in -water
work related to fill and/or water quality
impacts in Waters of the United States
(WOTUS)
Federal Emergency Management Agency
(FEMA) National Flood Insurance Program
(NFIP)
Any development in a floodplain, defined as
man-made change to improved or
unimproved real estate, requires a permit
Flood Control Management Act of 1935, RCW
86.16
Established statewide authority for floodplain
management.
70
a
and Regulation
Description
Presidential Executive Order 11988,
Floodplain Management (FEMA 1977)
Requires executive departments and
agencies (agencies) to avoid, to the extent
possible, the long- and short-term adverse
impacts associated with the occupancy and
modification of floodplains and to avoid
direct or indirect support of floodplain
development wherever there is a practicable
alternative.
The National Flood Insurance Act of 1968
Led to creation of the National Flood
Insurance Program (NFIP). The NFIP aims to
share the risk of flood losses through
insurance and reduce flood damages by
restricting floodplain development.
Flood Disaster Protection Act of 1973 (FEMA
1997)
Requires individuals, businesses and others
buying, building or improving property
located in identified areas of special flood
hazards within participating communities to
purchase flood insurance
State
Growth Management Act
Requires all cities and counties in Washington
to adopt development regulations that
protect critical areas
Shoreline Management Act of 1971 Chapter
90.58 RCW
Permitted uses in the shorelines of the state
shall be designed and conducted in a manner
to minimize, insofar as practical, any
resultant damage to the ecology and
environment of the shoreline area and any
interference with the public's use of the
water.
Section 401 of the Clean Water Act
The EPA delegated authority to Ecology to
review and certify Section 401 permits for
projects with in -water work in WOTUS
Water Quality Standards for Surface Waters
for the State of Washington Chapter 173-
201A WAC
Establishes water quality standards for
surface waters of the state of Washington
Chapter 77.55 RCW Construction Projects in
State Waters
Requires any hydraulic project in state waters
to adequately protect fish and their aquatic
habitats.
Chapter 90.44 RCW Regulation of public
groundwaters
Regulates and controls groundwaters of the
state
Chapter 90.48 RCW Water Pollution Control
Prevents and controls the pollution of the
waters of the state. Ecology has been
designated as the state water pollution
control agency
Chapter 90.54 RCW Water Resources Act of
1971
Protects water resources of the state, while
ensuring they are fully utilized.
Washington State Department of Fish and
Wildlife (WDFW) Hydraulic Project Approval
Ensures that construction in or near state
waters is done in such a way as to protect
fish and their aquatic habitats.
71
Law and Regulation
Description
Local
King County Critical Areas Ordinance (King
County Code [KCC] 21A.24)
This ordinance was developed under the
directives of the GMA to designate and
protect critical areas and to assist in
conserving the value of property,
safeguarding the public welfare, and
providing protection for these areas.
King County Public Water System Rules and
Regulations, Chapter 12 (12.24.010) — King
County.
Provides drinking water source protection
including protecting drinking water from
possible contaminants
Surface Water Runoff Policy in Chapter 9.04—
King County
Stormwater runoff and surface water and
erosion control.
City of Tukwila Environmentally Critical Areas
TMC 18.45
The purpose of TMC Chapter 18.45 is to
protect the environment, human life and
property; to designate and classify
ecologically critical areas including but not
limited to regulated wetlands and
watercourses and geologically hazardous
areas and to protect these critical areas and
their functions while also allowing for
reasonable use of public and private
property. These regulations are prepared to
comply with the Growth Management Act.
City of Tukwila Surface Water Management
TMC 14.30
The purpose of TMC Chapter 14.30 is to
regulate development activities that could
affect stormwater and non-stormwater
discharges to the stormwater drainage
system to the maximum extent practicable as
required by federal and state law
City of Tukwila Flood Plain Management TMC
16.52
This chapter ensures development activities
taking place in special flood hazard areas
promote the public health, safety, and
general welfare of residents.
City of Tukwila Grading TMC 16.54
The purpose of this chapter is to Prevent
damage to life, public and private property,
surface waters, sensitive areas and
associated buffers; regulate grading activities,
including excavation, fill, grading, earthwork
construction, and structural preloads; and
prevent erosion and control sedimentation.
4.2.3 Methodology
Project impacts are discussed as direct or indirect impacts that occur during construction or operation of
the proposed Project. Direct impacts are caused by the Project, and occur at the same time and place as
the Project. Indirect impacts are caused by the Project, and are later in time or farther removed in
distance from the Project, but are still reasonably foreseeable (40 CFR 1508.8). Construction impacts
occur during the construction, or building, of the Project, while operation impacts result from the
operations, or the utilization and maintenance of the Project, post -construction.
72
The potential impacts of construction and operation of each alternative on water resources were
evaluated based on the applicable federal, state, and local regulatory requirements. Potential impacts to
floodplains, surface waters, water quality, and groundwater were evaluated within their respective
study areas. Potential impacts were determined by the location of the footprint of the alternative as
well as impacts that extend beyond the area of the project footprint (e.g. stormwater pollution).
Where information is available, potential impacts to water resources are discussed quantitatively (e.g.
area of impervious surfaces created), and are otherwise discussed qualitatively. Impacts to the No
Action Alternative were determined based on the existing infrastructure's location to water resources.
The potential impacts to floodplains, surface waters, water quality, and groundwater are evaluated by
using the definitions in Table 4.2-6.
Table 4.2-6 Impact magnitude and description
Magnitude of Impact
Description
No Impact
The proposed Project would be fully consistent with the intent of applicable
plans and policies for floodplains, surface waters, water quality, and
groundwater.
Minor
The proposed Project would result in short-term temporary impacts, or minimal
long-term impacts to floodplains, surface waters, water quality, and
groundwater.
Moderate
The proposed Project would result in long-term or permanent impacts to
floodplains, surface waters, water quality, and groundwater, but mitigation can
be applied to reduce the impact to be less than significant.
Significant
The proposed Project would cause long-term, permanent, or irreversible
inconsistencies with applicable plans and policies or the zoning codes pertaining
to floodplains, surface waters, water quality, and groundwater.
4.2.4 Impacts Analysis
4.2.4.1 No Action Alternative
A detailed description of the No Action Alternative components and routes are provided in Section 3.3.
As shown in Figure 4.2-5, no wetlands were identified within the No Action Alternative, and one
watercourse, the Duwamish River, was identified within the No Action Alternative. Refer to Figure 4.2-2
for flood hazard zones of all Alternatives.
73
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4.2.4 1 1 Construction Dmpacts Associated with the No Action Alternative
Not Applicable. The No Action Alternative requires no construction, the truck route would remain along
its current course. There would be no impacts to floodplains, wetlands, streams, water quality, or
groundwater as a result of construction activities.
4.2..4.1.2. Operations Dmpacts Associated with the No Action Alternative
4.2.4.1.2.1 Floodplains
No impact. The No Action Alternative requires no construction. As such, there will be no impacts to
floodplains.
4.2.4.1.2.2 Wetlands
No impact. A buffer was not considered for the No Action Alternative because there is no new
construction. Current operating impacts will apply. As such, there will be no new impacts to wetlands
because of the No Action Alternative.
4.2.4.1.2.3 Streams
No impact. The current course of the No Action Alternative routes trucks over the Duwamish River via
the South 42nd Street Bridge and will not create any additional impact on the waterway that differ from
current operational conditions.
4.2.4.1.2.4 Water Quality
Minor impact. Increased truck traffic increases the potential for pollution, especially for contaminants
such as 6PPD-quinone. It is unclear what existing stormwater infrastructure is in place for the No Action
Alternative. New construction for Alternatives 2, 3B, and 4 will be required to abide by the most current
stormwater protections; however, the No Action Alternative will not construct anything new. Any
stormwater systems that are not up to date with the most current regulations will remain as -is.
4.2.4.1.2.5 Groundwater
No impact. No Action Alternative requires no construction. As such, groundwater flow will not be
affected.
4.2.4.2 Alternative 2: Airport Way South
A detailed description of this proposed Alternative's components and routes are provided in Section 3.4.
The Duwamish River is not within the study area of Alternative 2. Figure 4.2-7 shows the five wetlands
identified within the Alternative 2 study area: Wetlands 4 (4a and 4b), 5, 6, 7, and 9. The wetlands are
described as depressional with moderate levels of habitat functions. Two of these wetlands were
identified as Priority Habitat by the PHS viewer (WDFW n.d.c). Habitat scores range from 3 to 5
(Appendix C; Hruby and Yahnke 2023). The description of the wetlands can be found in Section 4.3.1.1.1;
refer to Figure 4.2-4 for flood hazard zones.
75
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4.2.4.2.1 Construction Dmpacts Associated with Alternative 2.
4.2.4.2.1.1 Floodplains
No Impact. Alternative 2 is not within the 100-year floodplain; therefore, no direct impacts are
anticipated from construction.
4.2.4.2.1.2 Wetlands
Moderate impact. Temporary impacts on wetlands, streams, and their respective buffers resulting from
construction may result from staging areas, temporary work areas, access roads, stream relocations,
cofferdams, clearing, stockpiles, or erosion and sediment controls. Dewatering may temporarily impact
groundwater discharge to wetlands. Other temporary impacts to wetlands and wetland buffers include
soil compaction, accidental spills of hazardous substances, noise and other disturbances, sedimentation,
and the introduction of invasive species.
Due to lack of construction details, it is assumed that a wetland will be filled wherever an alternative
footprint intersects with the wetland. Filling or excavating wetlands for means of construction will result
in loss of wetland area, alteration of surface or subsurface water flow, and changes in vegetation,
degrading the overall wetland functions. Affected wetland functions and values could include the
wetland's ability to provide floodway storage, detain stormwater, filter pollutants, protect streambanks,
and provide fish and wildlife habitat. Impacts to wetlands that affect plants and animals are discussed in
Section 4.3 Plants and Animals.
The type of wetland and vegetation present may affect the length of impact. Wetlands with emergent
vegetation are likely to recover faster than wetlands with woody vegetation due to the time it takes for
the respective vegetation to achieve pre -construction size and stature. All construction activities would
be performed using best management practices (BMPs) to minimize the disturbance that construction
may cause to the five wetlands within Alternative 2.
4.2.4.2.1.3 Streams
No Impact. There are no streams within Alternative 2.
4.2.4.2.1.4 Water Quality
Minor impacts. Construction activities of Alternative 2 would result in direct impacts to water quality
and would be temporary in duration. Activities such as vegetation clearing, grading, or excavating may
erode soil when exposed to wind, rainfall, or vehicle activity. Construction stormwater runoff could carry
these soils into waterways, creating water quality issues including turbidity, sedimentation, and the
transport of pollutants. Impacts and mitigation measures to soils are discussed in Section 4.1
Geology/Soils. There is potential for hazardous chemicals to spill, leading to surface water or
groundwater contamination through runoff. The impacts and mitigation measures for hazardous
chemicals are discussed in Section 4.7 Health and Safety.
Any selected alternative of the proposed Project would be developed in accordance with the current
stormwater management standards in the King County Surface Water Design Manual, and appropriate
mitigation measures and BMPs will be followed minimizing or avoiding most of the impacts of
stormwater runoff. With the implementation of mitigation measures and BMPS, temporary impacts to
water quality from vegetation clearing, grading, erosion, sedimentation, and pollutants can be avoided.
77
4.2.4.2.1.5 Groundwater
Minor Impacts. Temporary impacts on groundwater resulting from construction may result from
temporary land conversion to impervious surfaces not included within the alternative footprint including
staging areas, temporary work areas, clearing, stockpiles, and access roads. Other potential construction
activities that could affect local hydrology include stream relocations and dewatering of wetlands which
may temporarily impact groundwater discharge.
4.2.4.2.2 Operations Dmpacts A.s.sociated with Alternative 2.
4.2.4.2.2.1 Floodplains
Minor Impact. Indirect impacts could result from the addition of impervious surfaces. An increase in
impervious surfaces could increase surface water runoff and affect hydrology by altering base or peak
flows within the floodplain. Existing conditions within the Alternative 2 footprint are currently covered
with grass/low-lying vegetation or tree canopy. Impervious surfaces currently occupy 2.98 acres, or
10.6%, of the Alternative 2 footprint. The completed infrastructure of proposed Alternative 2 would
increase the area of impervious surfaces to approximately 28.18 acres, which is an additional 25.2 acres
of new impervious surfaces.
Table 4.7.7 Land Cover within Alternative 2
Landcover Class
Area within Project Footprint (acres)
Bare Soil
2.23
Grass/Low-Lying Vegetation
11.84
Impervious Surfaces
2.98
Open Water
0.15
Tree Canopy
10.75
Unclassified (Unincorporated King County)
0.23
Total
28.18
Drainage issues were listed as one of the primary surface water problems faced by the Duwamish River
(Figure 4.2-4; CH2M Hill 2013). The primary cause of drainage issues arises from lack of storm drainage
systems, damaged or poorly maintained conveyance systems, and inadequate hydraulic capacity of
conveyance systems. Potential mitigation measures for these issues are discussed in Section 4.1.5.1.
4.2.4.2.2.2 Wetlands and Streams
Mitigated Significant Impact. Alternative 2 does not intersect with a stream or stream buffer. Therefore,
there are no impacts to streams or stream buffers. Of the proposed alternatives, Alternative 2 has the
greatest extent of direct impact on wetlands and wetland buffers based on acres of area affected. Four
wetlands, three with moderate levels of habitat functions and one with low levels of habitat function,
totaling 1.42 acres would be permanently impacted by this alternative. The wetland buffers associated
with this impact would total 5.7 acres (Table 4.2-8).
78
Table 4.2 8 Wetland Impacts in the Alternative 2 Study Area
Wetland Name
Wetland Area Impacted by Project
footprint (acres)
Wetland Buffer Area Impacted by
Project footprint (acres)
Total Area Impacted by Project
footprint (acres)
4a
0.32
1.17
1.50
4b
0.11
0.67
0.77
5
0.54
0.67
1.21
6
0.03
0.82
0.85
7
0.42
2.37
2.79
9
0.00
0.00
0.00
Total
1.42
5.7
7.12
Following construction, there would be an increase in the amount of stormwater runoff generated due
to the presence of additional impervious surfaces. This additional runoff increases the potential for
contamination of receiving waterbodies. Additionally, increased impervious surfaces alter hydrology by
decreasing the percolation of surface water. This effect results in lower base flows as well as higher peak
flows which can result in scour or deposition downstream. Assuming BMPs and mitigation measures are
put in place, those impacts should be minimal. Mitigation measures are discussed in Section 4.1.5.2
4.2.4.2.2.3 Water Quality
Moderate impacts. Potential operation impacts to water quality could result from the permanent loss of
wetlands, buffers, and their associated functions, and to changes to hydrologic conditions. Operations
impacts to water quality have the potential to be substantial if not effectively mitigated. An increase in
stormwater runoff due to an increase in impervious surfaces could result in elevated pollutant loads in
local waterways. Mitigation measures for potential impacts to water quality are discussed in Section
4.2.5.3.
4.2.4.2.2.4 Groundwater
Minor impacts. There would be long-term impacts to groundwater within the study area due to the
post -construction conditions of proposed Alternative 2. Land cover conversion to impervious surfaces
would alter the infiltration and percolation of surface water into the ground potentially affecting
groundwater recharge (See Table 4.2-7).
Alternative 2 would have the greatest construction of new impervious surfaces. Impervious surfaces
currently comprise 2.98 acres (10.6% of the proposed Alternative 2 footprint). If Alternative 2 is
constructed the entire footprint, 28.18 acres, would be converted to impervious ones.
4.2.4..E Alternative 3B: Improvements to 48th Place South
A detailed description of this proposed Alternative's components and routes are provided in Section
3.3.2. Figure 4.2-8 shows the Duwamish River and four wetlands identified within the Alternative 3B
study area: Wetlands 1, 2, 3, and 8. Three of these wetlands were classified as tidal fringe, and one was
classified as depressional. Habitat scores range from 5 to 6 (Appendix C; Hruby and Yahnke 2023). The
description of the wetlands can be found in Section 4.2.1.3.1.
One waterway, the Duwamish River, is found within the Alternative 3B study area Figure 4.2-7; Table
4.2-2). The Duwamish River is classified as a Type S stream. According to King County Code (K.C.C.)
79
21A.24.345, Type S waters include all aquatic areas inventoried as "shorelines of the state" under the
King County's Shoreline Master Program. The stretch of Duwamish River adjacent to the Alternative 3B
study area is located within the Duwamish Estuary, which includes the extent of tidal influence from the
mouth to river mile 12 (King County et.al. 2001). The Duwamish River was historically, and is regularly
dredged, to maintain a navigable waterway. This action, paired with the tidally influenced water levels,
have resulted in steep and unvegetated banks. Both banks are armored with riprap within the study
area and contain patches of unvegetated and subtidal substrates.
Refer to Figure 4.2-2 for flood hazard zones for this alternative.
80
Altern,tive 3B
< Lt
0
R., h
111 I I 1111
01.10,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,,m •
0110000010000000000000000000000000000000000000000000001 111111
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Mdd
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4.2.4.3.1 Construction Dmpacts Associated with Alternative 3B
4.2.4.3.1.1 Floodplains
No impact or Minor impact. Depending upon the final design of the proposed bridge, Alternative 3B
construction element may be within 100-year floodplain. If Alternative 3B occurs within the floodplain, a
Special Flood Hazard Area (SFHA) permit will be required. Alternative 3B intersects two revetments
where it spans the Duwamish River between RM 8.6 and RM 8.7. Levees are located between RM 7.9
and RM 8.3 to the east of the proposed Alternative 3B footprint. Alternative 3B is approximately 200
feet east of an additional SFHA located in Codiga Park.
This alternative has the potential to impact the Duwamish River and its associated floodplain.
Alternative 3B would construct a bridge that would cross the Duwamish and likely include in -water
work. Impacts to the floodplain will be mitigated through issuance of the SFHA permit which requires
that development in the floodplain will be reasonably safe from flooding.
4.2.4.3.1.2 Wetlands and Streams
Moderate impact. Construction of proposed Alternative 3B may result in temporary impacts on
wetlands, streams, and their respective buffers due to staging areas, temporary work areas, access
roads, stream relocations, cofferdams, clearing, stockpiles, or erosion and sediment controls.
Dewatering may temporarily impact groundwater discharge to wetlands. Other temporary impacts to
wetlands and wetland buffers include soil compaction, accidental spills of hazardous substances, noise
and other disturbances, sedimentation, and the introduction of invasive species.
Due to lack of construction details, it is assumed that a wetland will be filled wherever an alternative
footprint intersects with the wetland. Filling or excavating wetlands for means of construction will result
in loss of wetland area, alteration of surface or subsurface water flow, and changes in vegetation,
degrading the overall wetland functions. Affected wetland functions and values could include the
wetland's ability to floodway storage, detain stormwater, filter pollutants, protect streambanks, and
provide fish and wildlife habitat. Impacts to wetlands that affect plants and animals are discussed in
Section 4.3 Plants and Animals.
The type of wetland and vegetation present may affect the length of impact. Wetlands with emergent
vegetation are likely to recover faster than wetlands with woody vegetation due to the time it takes for
the respective vegetation to achieve pre -construction size and stature. Potential mitigation of
construction impacts on wetlands is discussed in Section 4.2.5.2.
Moderate Impact. This alternative has the potential to impact the Duwamish River. Construction of
Alternative 3B would include a bridge that would cross the Duwamish and in -water work would likely
occur. The bridge that would cross the Duwamish River has not yet been designed, so exact impacts are
unknown. However, in 2022 Trantech Engineering LLC designed a bridge for a previous alternative that
has since been dismissed (Trantech 2022). This design was used to inform assumptions about the bridge
that would be constructed for Alternative 3B including:
1. The preferred bridge alignment is a three -span steel plate girder with six feet of freeboard which
would be above the 100-year flood zone
2. In -water construction will include a temporary falsework bent for steel erection and would include
work platforms near the shoreline that extend into the river below HTL. The bent would require pile
driving
82
3. The piers supporting the bridge would be below HTL
Potential mitigation of construction impacts on streams is discussed in Section 4.2.5.2.
4.2.4.3.1.3 Water Quality
Minor impacts. Construction activities of Alternative 3B would result in direct impacts to water quality
and would be temporary in duration. Activities such as vegetation clearing, grading, or excavating may
erode soil when exposed to wind, rainfall, or vehicle activity. Construction stormwater runoff could carry
these soils into waterways, creating water quality issues including turbidity, sedimentation, and the
transport of pollutants. Impacts and mitigation measures to soils are discussed in Section 4.1
Geology/Soils. There is potential for hazardous chemicals to spill, leading to surface water or
groundwater contamination through runoff. The impacts and mitigation measures for hazardous
chemicals are discussed in Section 4.7 Health and Safety.
Any selected alternative of the proposed Project would be developed in accordance with the current
stormwater management standards in the King County Surface Water Design Manual and appropriate
mitigation measures and BMPs will be followed minimizing or avoiding most of the impacts of
stormwater runoff. With the implementation of mitigation measures and BMPS, temporary impacts to
water quality from vegetation clearing, grading, erosion, sedimentation, and pollutants can be avoided.
4.2.4.3.1.4 Groundwater
Minor Impacts. Temporary impacts on groundwater resulting from construction may result from
temporary land conversion to impervious surfaces not included within the alternative footprint including
staging areas, temporary work areas, clearing, stockpiles, and access roads. Other potential construction
activities that could affect local hydrology include stream relocations and dewatering of wetlands which
may temporarily impact groundwater discharge.
4.2..4.3.2. Operations Dmpacts A.s.sociated with Alternative 3B
4.2.4.3.2.1 Floodplains
No or Minor Impact. Alternative 3B would be located within the 100-year floodplain due to the
construction of the bridge over the Duwamish River, a regulatory floodway. The NFIP prohibits
development that encroaches the regulatory floodway unless it can be proven that the 100- year flood
level will not increase. A No -Rise Certification must be documented through both hydrologic and
hydraulic analyses. The current level of design of the proposed Project precludes a meaningful analysis
of the impact Alternative 3B may have on the 100-year floodplain; however, it is assumed the bridge
design will follow the NFIP criteria and would not increase the 100-year flood level. Therefore, it is
unlikely that Alternative 3B would result in direct impacts to the 100-year floodplain.
Indirect impacts could result from the addition of impervious surfaces. An increase in impervious
surfaces could increase surface water runoff and affect hydrology by altering base or peak flows within
the floodplain. Existing conditions within the Alternative 3B footprint have very little vegetation.
Impervious surfaces currently occupy 2.19 acres, or 73.49%, of the proposed alternative footprint.
Alternative 3B would increase the area of impervious surfaces to approximately 2.87 acres which is an
additional 0.68 acres of new impervious surfaces.
83
Table 4.2-9 Landcover of Alternative .3B
Landcover Class
Area within Project Footprint (acres)
Bare Soil
0.02
Grass/Low-Lying Vegetation
0.14
Impervious Surfaces
2.19
Open Water
0.11
Tree Canopy
0.41
Unclassified (Unincorporated King County)
0.00
Total
2.87
4.2.4.3.2.2 Wetlands and Streams
Mitigated Significant Impact. Alternative 3B has the least amount of impact on wetlands and wetland
buffers based on acres of area affected. Four wetlands totaling 0.11 acres would be permanently
impacted by this alternative. The wetland buffers associated with this impact would total 0.65 acres.
This alternative would require a bridge crossing the Duwamish River with five feet of minimum
freeboard above the river. In order to achieve the required clearances above the river, Railroad Avenue
would need to be raised to align with the new grade changes. This elevation adjustment would require
the construction of retaining walls along the eastern edge of Railroad Avenue to support the new grade
change. Elevated structures have the potential to impact vegetation; however, the quality and density of
existing vegetation is unknown. If this alternative is chosen as the Preferred Alternative, vegetation
surveys would need to be conducted to assess the impact on wetlands.
Table 4.2-10 Direct impacts to wetlands in the Alternative .3B study area
Wetland
Name
Wetland Area Impacted by
Project footprint (acres)
Wetland Buffer Area Impacted
by Project footprint (acres)
2 0.00 0.00
0.10 0.27w`
8 0.01 0.19
Total 0.11 0.65
Total Area Impacted by
Project footprint (acres)
0.00
0.37
0.19
0.76___.__
Following construction, there would be an increase in the amount of stormwater runoff generated due
to the addition of impervious surfaces. This additional runoff increases the potential for contamination
of receiving waterbodies. Additionally, increased impervious surfaces alter hydrology by decreasing the
percolation of surface water. This effect results in lower base flows as well as higher peak flows which
can result in scour or deposition downstream. Assuming BMPs and mitigation measures are put in place,
those impacts should be minimal. Mitigation measures are discussed in Section 4.2.5.2.
4.2.4.3.2.3 Water Quality
Moderate impacts. Potential operation impacts to water quality could result from the permanent loss of
wetlands, buffers, and their associated functions, and to changes to hydrologic conditions. Operations
impacts to water quality have the potential to be substantial if not effectively mitigated. An increase in
stormwater runoff due to an increase in impervious surfaces could result in elevated pollutant loads in
84
local waterways. Mitigation measures for potential impacts to water quality are discussed in Section
4.2.5.3.
4.2.4.3.2.4 Groundwater
Minor impacts. There would be long-term impacts to groundwater within the study area due to the
post -construction conditions of proposed Alternative 3B. Land cover conversion to impervious surfaces
would alter the infiltration and percolation of surface water into the ground potentially affecting
groundwater recharge (See Table 4.2-9).
Alternative 3B would increase the area of impervious surfaces to approximately 2.87 acres which is an
additional 0.68 acres of new impervious surfaces. If Alternative 3B were constructed, the percentage of
impervious surfaces in this footprint area would increase from 73.49%, to 100%.
4.2.4.4 Alternative 4: New Bridge from SR 900 (MLK Jr Way) to South 129th Street
A detailed description of this proposed Alternative's components and routes are provided in Section
3.3.3. Figure 4.2-8 shows the Duwamish River and four wetlands identified within the southern portion
of the Alternative 4 study area: Wetlands 1, 2, 3, and 8. Figure 4.2-9 shows Stream 1 and three wetlands
identified within the northern portion of the Alternative 4 study area: Wetlands 10, 11, and 12.
Wetlands 1, 2, and 8 met special estuarine characteristics. Wetland 3 has high water quality and
hydrologic functions. Wetlands 10 and 11 have moderate water quality and hydrologic functions.
Wetland 12 has high water quality and moderate hydrologic functions. Habitat scores range from 5 to 6
(Appendix C; Hruby and Yahnke 2023). The description of the wetlands can be found in Section 4.2.1.3.1.
Two waterways, the Duwamish River and Stream 1, are found within the Alternative 4 study area. The
Duwamish River is described in detail in Section 4.2.4.3. Stream 1 is mapped by the City of Tukwila (City
of Tukwila 2024 in Appendix C) as a Type F stream which is defined as a perennial stream that is known
to be used by fish or has the potential to be used by fish. This stream was not accessed during field
reconnaissance. The mapped stream flows through a narrow ravine with a mature broadleaf maple
canopy before flowing to Martin Luther King Jr Way South. Inlet protection for a potential culvert or
pipe was observed from the roadway in this area. Stream 1 has an unknown outlet and is assumed to
discharge to the large wetland complex to downslope and in between 1-5 and the BNSF operations yard.
Stream 1 was assumed to support an associated wetland (Wetland 12). There is no documented fish use
(WDFW 2024a, 2024b, 2024c).
Refer to Figure 4.2-2 for flood hazard zones of Alternative 4.
85
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1 110
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42.4.4.1 [onctruction|mpacts Associated with Alternative 4
4.2.4/411 F|oodp|ains
No Impact. Proposed Alternative 4 would not be located within the 100-year floodplain despite its close
proximity to the Duwamish River. Alternative 4 is approximately 40-100 feet east of the same
revetments as Alternative 313, and Alternative 4 is approximately 150 feet to the east the SFHA in Codiga
Park.
4.2.4/412 Wetlands and Streams
Moderate lnnpecL Construction ofproposed Alternative 4could result in temporary impacts on
wetlands, streams, and their respective buffers from staging areas, temporary work areas, access roads,
stream relocations, cofferdams, clearing, stockpiles, orerosion and sediment controls. Devvaterin0 may
temporarily impact groundwater discharge to wetlands. Other temporary impacts to wetlands and
wetland buffers could include soil compaction, accidental spills ofhazardous substances, noise and
other disturbances, sedimentation, and the introduction of invasive species.
Due tolack ofconstruction details, itisassumed that awetland will befilled wherever analternative
footprint intersects with the wetland. Filling orexcavating wetlands for means ofconstruction will result
in loss of wetland area, alteration of surface or subsurface water flow, and changes in vegetation,
degrading the overall wetland functions. Affected wetland functions and values could include the
wetland's ability tof|oodw/aystorage, detain stormw/ater, filter pollutants, protect streambanks, and
provide fish and wildlife habitat. Impacts towetlands that affect plants and animals are discussed in
Section4.] Plants and Animals.
The type of wetland and vegetation present may affect the length of impact. Wetlands with emergent
vegetation are likely to recover faster than wetlands with woody vegetation due to the time it takes for
the respective vegetation to achieve pre -construction size and stature. Potential mitigation of
construction impacts on wetlands is discussed in Section 4I5.2Water Quality
4.2.4/413 Water Quality
Minor impacts. Construction activities ofAlternative 4would result indirect impacts towater quality
and would be temporary in duration. Activities such as vegetation clearing, grading, or excavating may
erode soil when exposed to wind, rainfall, or vehicle activity. Construction stormw/ater runoff could carry
these soils into waterways, creating water quality issues including turbidity, sedimentation, and the
transport of pollutants. Impacts and mitigation measures to soils are discussed in Section 4.1
Geology/Soils. There is potential for hazardous chemicals to spill, leading to surface water or
groundwater contamination through runoff. The impacts and mitigation measures for hazardous
chemicals are discussed inSection 47Health and Safety.
Any selected alternative of the proposed Project would be developed in accordance with the current
stormwater management standards in the King County Surface Water Design Manual and appropriate
mitigation measures and BMPs will be followed minimizing or avoiding most of the impacts of
stormvvater runoff. With the implementation of mitigation measures and BMPS, temporary impacts to
water quality from vegetation clearing, grading, erosion, sedimentation, and pollutants can be avoided.
88
4.2.4.4.1.4 Groundwater
Minor Impacts. Temporary impacts on groundwater resulting from construction may result from
temporary land conversion to impervious surfaces not included within the alternative footprint including
staging areas, temporary work areas, clearing, stockpiles, and access roads. Other potential construction
activities that could affect local hydrology include stream relocations and dewatering of wetlands which
may temporarily impact groundwater discharge.
4.2.4.4.2 Operations Dmpacts A.s.sociated with Alternative 4
4.2.4.4.2.1 Floodplains
Minor Impact. Indirect impacts could result from the addition of impervious surfaces. An increase in
impervious surfaces could increase surface water runoff and can affect hydrology by altering base or
peak flows within the floodplain. Existing conditions within the Alternative 4 footprint are a mix of
unclassified land cover, tree canopy, and impervious surfaces. Impervious surfaces currently occupy 1.73
acres, or 26.25%, of the proposed alternative footprint. Alternative 4 would increase the area of
impervious surfaces to approximately 6.59 acres which is an additional 4.86 acres of new impervious
surfaces (or 100% of the Alternative 4 footprint).
Table 4.2-11 Landcover of Alternative 4
Landcover Class
Area within Project Footprint (acres)
Bare Soil
0.03
Grass/Low-Lying Vegetation
0.53
Impervious Surfaces
1.73
Open Water
0.00
Tree Canopy
1.84
Unclassified (Unincorporated King County)
2.46
Total
6.59
4.2.4.4.2.2 Wetlands and Streams
Mitigated Significant Impact Alternative 4 has slightly more impact than Alternative 3B on wetlands and
wetland buffers based on affected acreage. Three wetlands with low to moderate levels of habitat
functions totaling 0.18 acres would be permanently impacted by Alternative 4. The wetland buffers
associated with this impact would total 0.74 acres. The quality of wetlands affected are marginally lower
quality than Alternatives 2 and 3B.
This alternative will require a noise wall that would be installed between the new truck access road and
51st Place South, and would require a tall retaining wall to be constructed to support the hillside.
Elevated structures have the potential to impact vegetation; however, the quality and density of existing
vegetation is unknown at this time. If this Alternative is chosen as the Preferred Alternative, vegetation
surveys would need to be conducted to assess the impact on wetlands.
89
Table 4.2-12 Direct impacts to wetlands in Alternative 4 study area
Wetland
Name
2
8
0
11
12a
12b
Total
Wetland Area Impacted by Project
footprint (acres)
0.00
0.00
0.03
0.01
0.00
0.18
Wetland Buffer Area
Impacted by Project
footprint (acres)
0.00 0.00
0.00 0.00
Total Area Impacted by Project
footprint (acres)
0.00 0.00
026
0.27 0.30
0.17
0.00 0.00
0.74_._._w 092
Following construction, there would be an increase in the amount of stormwater runoff generated due
to additional impervious surfaces. This additional runoff would increase the potential for contamination
of receiving waterbodies. Additionally, increased impervious surfaces alter hydrology by decreasing the
percolation of surface water. This effect results in lower base flows as well as higher peak flows which
can result in scour or deposition downstream. Assuming BMPs and mitigation measures are put in place,
those impacts should be minimal. Mitigation measures are discussed in Section 4.2.5.
4.2.4.4.2.3 Water Quality
Moderate impacts. Potential operation impacts to water quality could result from the permanent loss of
wetlands, buffers, and their associated functions and changes to hydrologic conditions. Operations
impacts to water quality have the potential to be substantial if not effectively mitigated. An increase in
stormwater runoff due to an increase in impervious surfaces could result in elevated pollutant loads in
local waterways. Mitigation measures for potential impacts to water quality are discussed in Section
4.2.5.3.
4.2.4.4.2.4 Groundwater
Minor impacts. There would be long-term impacts to groundwater within the study area due to the
post -construction conditions of proposed Alternative 4. Land cover conversion to impervious surfaces
would alter the infiltration and percolation of surface water into the ground potentially affecting
groundwater recharge (See TableTable 4.2-11)
Alternative 4 would increase the area of impervious surfaces to approximately 6.59 acres which is an
additional 4.86 acres of new impervious surfaces. If Alternative 4 were constructed, the percentage of
impervious surfaces in this footprint area would increase from 26.3% to 100%.
4.2.5 Mitigation Measures
This section describes mitigation measures that may be implemented to avoid or minimize construction
and operation impacts on water resources during the proposed Project.
90
4.2.5.1 Floodplains
Impacts from the addition of impervious surfaces for Alternatives 2, 3B, and 4 will be mitigated by
stormwater infrastructure. The proposed Project design does not currently include stormwater facilities,
but when they are integrated into the design of the Project the construction of new or replacement of
old stormwater infrastructure will likely provide a long-term minor positive impact on the 100-year
floodplain by reducing surface water run-off.
For Alternative 3B, a No -Rise Certification must be documented through both hydrologic and hydraulic
analyses which will negate any long-term impacts the Alternative 3B bridge will have on the 100-year
floodplain.
4.2.5.2 Wetlands and Streams
Current hydrology sources need to be identified and maintained in order to preserve on -site wetland
hydroperiods.
All adverse effects to wetlands must be mitigated in accordance with the State of Washington's
Governor's Executive Order (EO) 89-10. State and federal E0s and regulations require mitigation, and
the preferred mitigation sequencing requires the applicant to:
1. Avoid impacts to wetlands and other aquatic resources.
2. Minimize unavoidable impacts to the greatest extent feasible.
3. Compensate for unavoidable impacts through required compensatory mitigation.
Guidance for selecting a compensatory mitigation option can be found in the Final Rule on
Compensatory Mitigation for Losses of Aquatic Resources (73 FR 19594). Compensatory mitigation
would be implemented in accordance with applicable federal, state, and local requirements and
guidelines. Mitigation sites would be identified close to impacts and compensate for lost values in -kind
to the maximum extent possible.
Mitigation sequencing must be applied prior to developing a compensatory mitigation plan. Once an
alternative is selected, the applicant would develop a conceptual mitigation plan and would work with
Ecology to refine the plan. Compensatory mitigation options include:
1. Wetland mitigation banking: The wetland mitigation bank is a site where wetlands are restored,
created, or enhanced with the intention to sell credits. The permittee would purchase credits from a
wetland mitigation bank to offset the unavoidable impacts of the proposed project.
2. In -lieu fee mitigation: The permittee would pay a fee to a third party in lieu of conducting project -
specific mitigation or buying credits from a mitigation bank.
3. Advance permittee-responsible mitigation: Prior to the project impacting wetlands, the permittee
would implement a compensatory mitigation plan that would generate credits over time.
All construction activities would be performed using best management practices (BMPs) to minimize the
disturbance that construction may cause to the wetlands within each alternative.
91
4.2.5..E Water (:Quality
In order to minimize the effects on water quality, prior to construction the applicant would be required
to obtain coverage under the National Pollutant Discharge Elimination System (NPDES) through a
Construction Stormwater General Permit to help control runoff and reduce water pollution from the
construction site. The Stormwater Pollution Prevention Plan (SWPPP) (in conformance with
requirements in the City of Tukwila Stormwater Management Program Plan and the Infrastructure
Design and Construction Standards, the King County Surface Water Design Manual and City of Seattle
Stormwater Manual). The SWPPP would include the following plans:
• Spill prevention, control, and countermeasures (SPCCP) to outline requirements for and
implementation of spill prevention, inspection protocols, equipment, material containment
measures, and spill response procedures.
• Temporary erosion and sediment plan to identify, reduce, eliminate, or prevent sediment and
erosion problems.
• Concrete containment and disposal plan to outline the management, containment, and disposal
of concrete debris, slurry, and dust
• Dewatering plan that outlines procedures for pumping groundwater away from the construction
area and for storing, testing, treating, and discharging or disposing the water, as necessary.
Stormwater systems, including water quality treatment, are not available for Alternative 2, 3B, or 4, and
will not be designed until a Preferred Alternative is selected. All stormwater systems would be designed
in accordance with the Tukwila Stormwater Management Program Plan and the Infrastructure Design
and Construction Standards, as well as the King County Surface Water Design Manual and Seattle
Stormwater Manual.
4.2.5.4 Groundwater
Surface and groundwater hydrology monitoring would be conducted prior to impacts to all onsite
wetlands to determine hydroperiods in order to develop effective plans to preserve current hydrology
4.2.6 Significant Unavoidable Adverse Impacts
The construction and operation of the proposed Project would not result in any unavoidable adverse
impacts on water resources. Permanent changes to the wetlands in the proposed Project footprint
would result from the construction of the proposed project which would alter hydrology within the
Project vicinity; however, mitigation is required and would lessen the impact. Additionally, the
footprints of the Alternatives and area of water resources impacted are generally small compared to the
size of the watershed and would have little impact on a larger scale.
92
4.3 IPllaints and Aniimalls
This section provides an analysis of potential impacts to plant and animal communities and their
available habitat resulting from the construction and operation of proposed Alternatives 2, 3B, and 4, as
well as the No Action Alternative. This section also identifies proposed mitigation measures for potential
impacts.
4.3.1 Affected Environment
The Project vicinity, or general area surrounding where the selected alternative of the Project would
take place, includes a range of habitats that support both aquatic and terrestrial species. Plants and
animals present in the Project vicinity were divided into three study areas: wetlands, aquatic species and
habitat, and terrestrial species and habitat. Each study area includes the footprint for the respective
alternative (No Action Alternative, Alternative 2, Alternative 3B, or Alternative 4) and for the specified
adjacent areas that could be affected by Project activities.
4.3.1.1 Wetlands
The wetland study areas for the proposed Alternatives include wetlands that are within 300 feet of the
edges of the long-term proposed Alternative footprints, which are defined as the physical footprint of
the existing truck route (Figure 4.3-1) and the areas that would need to be constructed and the truck
access routes, of the No Action Alternative, Alternatives 2 (Figure 4.3-2), 3B (Figure 4.3-3), and 4 (Figure
4.3-4 and Figure 4.3-5).
No Action Alternative: No wetlands were identified in the No Action Alternative study area.
Alternative 2: Five depressional wetlands (Wetland 4 through Wetland 7 and Wetland 9) were identified
within the Alternative 2 study area with moderate levels of habitat functions, see Figure 4.3-2. Wetlands
4, 5, and 9 were identified as Priority Habitat by the Priority Habitats and Species (PHS) viewer (WDFW
n.d.a). Habitat scores range from 3 to 5 (Appendix C).
Alternative 3B: Four wetlands (Wetland 1 through Wetland 3 and Wetland 8) were identified within
Alternative 3B with moderate levels of habitat functions, see Figure 4.3-3. Three of these wetlands were
classified as tidal fringe, and one was classified as depressional. Habitat scores range from 5 to 6
(Appendix C).
Alternative 4: Seven wetlands (Wetland 1 through Wetland 3, Wetland 8, and Wetland 10 through
Wetland 12) were identified within Alternative 4 (Figure 4.3-4 and Figure 4.3-5) with moderate levels of
habitat functions. Habitat scores range from 5 to 6 (Appendix C).
Twelve existing wetlands were identified and documented along or near the existing truck route (the No
Action Alternative) and Alternatives 2, 3B, and 4, see Table 4.3-1. Three wetlands were accessed during
field reconnaissance surveys to collect wetland hydrology, soils, and vegetation data. This section briefly
describes each of the wetlands and their habitat functions, and Section 4.2Water Resources describes
their water quality and hydrologic features. Detailed descriptions of the wetlands are available in the
report prepared by HDR (Appendix C). Detailed wetland determination data forms and wetland rating
forms are provided in Appendix C.
93
La
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4.3.1.1.1 Wetland Descriptions
Wetland 1 is a narrow tidal fringe wetland located on the east bank of the Duwamish River. It was
observed from Railroad Avenue and was observed to contain palustrine scrub -shrub and estuarine
intertidal emergent habitats. The palustrine scrub -shrub was densely vegetated by Himalayan blackberry
(Rubus armeniacus) and willow. The herbaceous stratum was vegetated by reed canarygrass (Phalaris
arundinacea), and the high tide during the field reconnaissance covered other potential herbaceous
species.
Wetland 2 is a tidal fringe wetland located within Codiga Park. It was observed to contain palustrine
forested and scrub -shrub habitats, and estuarine intertidal emergent habitats were observed from
Codiga Park's public trail. The palustrine forested habitat was vegetated by black cottonwood (Populus
balsamifera) and red alder (Alnus rubra), with the scrub -shrub habitat consisting of willow species. The
estuarine intertidal emergent habitat included Lyngbye's sedge (Carex lyngbyei) and slough sedge (C.
obnupta).
Wetland 3 is a depressional wetland that is located in a low spot between two BNSF operations yard
storage areas and north of South 129th Street. Wetland 3 was observed to have palustrine forested and
scrub -shrub habitats comprised of black cottonwood, red alder, and Himalayan blackberry. The wetland
drains from the north to the south, and a culvert outlet was observed that discharges directly to the
Duwamish River approximately 110 feet to the south.
Wetland 4a is a depressional wetland bordered by road and railroad prisms and a steep hillslope. It was
observed to have palustrine forested, scrub -shrub, and emergent habitats. The forested habitat was
dominated by black cottonwood and willow (Salix sp.). The scrub -shrub habitat included red osier
dogwood (Cornussericea), salmonberry (Rubusspectabilis), and willow species. The herbaceous stratum
included reed canarygrass, other unidentified grasses, and climbing nightshade (Solanum dulcamara)
occurring as woody vines.
Wetland 4b is a depressional wetland bordered by road and railroad prisms and a steep hillslope. It was
observed to have palustrine forested, scrub -shrub, and emergent habitats. The forested habitat was
dominated by black cottonwood and red alder. The scrub -shrub habitat included red osier dogwood and
Himalayan blackberry. The herbaceous stratum included climbing nightshade occurring as woody vines.
Wetland 5 is a depressional wetland that is in a topographic depression bordered by Airport Way South,
South Boeing Access Road, and the BNSF operations yard. The wetland was observed to have palustrine
forested, scrub -shrub, and emergent habitats. The forested habitat was dominated by black
cottonwood, willow, and red alder. The scrub -shrub habitat included red osier dogwood, rose spirea
(Spiraea douglasii), and willow species. The herbaceous stratum included broadleaf cattail (Typha
latifolia), reed canarygrass, and other unidentified grasses.
99
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EEM = estuarine emergent; PEM = palustrine emergent; PFO = palustrine forested; PSS = palustrine scrub -shrub.
Wetland 6 is a depressional wetland located on the SPAA property within the shooting range bordered
by a sand embankment. The wetland could not be viewed from public ROW. Based on the delineation
(Watershed 2023 in Appendix C) the wetland is a palustrine emergent wetland vegetated by reed
canarygrass, creeping buttercup (Ranunculus repens), and other facultative grasses. The wetland is
supported by seasonally high-water table and saturation.
Wetland 7 is a depressional wetland located on the Seattle City Light transmission ROW and was not
observed in the field. This wetland includes palustrine scrub -shrub and emergent habitats within the
Project study area and off -site palustrine forested habitat. 2013 aerial imagery shows construction
activities and the placement of fill material within Wetland 7, with potential compensatory mitigation
occurring in 2017. The potential compensatory mitigation is evidenced by the installation of
microtopography, large wood material, and sapling plantings. Surface water appears to extend off site
under mature trees adjacent to the BNSF operations yard.
Wetland 8 is a narrow tidal fringe wetland located on the right bank of the Duwamish River. It is similar
to, and shares the same description and functions as, Wetland 1. Wetlands 1 and 8 are contiguous on
both banks of the Duwamish River and are separated by an unvegetated channel greater than 50 feet.
Wetland 9 is a depressional wetland and assumed to be hydrologically connected to Wetland 5. Wetland
9 is separated from the Project and Wetland 5 by the approximately 200-foot-wide BNSF operations
yard. The east, west, and southern boundaries of Wetland 9 are marked by the steep fill prisms
associated with the operations yard, South Boeing Access Road, and uplands associated with 1-5.
Wetland 9 could extend offsite to the north. The wetland was observed to have palustrine forested,
scrub -shrub, and emergent habitats with vegetation similar to that of Wetland 5. The forested habitat
was dominated by willow and red alder. The scrub -shrub habitat included red osier dogwood, rose
spirea, and willow species. The herbaceous stratum included broadleaf cattail and reed canarygrass.
Wetland 10 is a depressional wetland that is located within a drainage that slopes from the northeast to
the southwest toward 1-5. Observed wetland vegetation includes willow, black cottonwood, and
Himalayan blackberry. This wetland was partially delineated (Wet.Iand 2022 in Appendix C) and was
described as having Oregon ash, English hawthorn (Crataegus monogyna), salmonberry, and English Ivy.
Surface water near the bottom of the drainage was observed adjacent to the 1-5 road prism.
Wetland 11 is a small slope wetland that is located to the south of Stream 1 and Wetlands 12a and 12b.
Wetland 11 is described as having palustrine forested, scrub -shrub, and emergent habitats vegetated by
black cottonwood, Pacific willow (Salix lucida), cascara (Frangula purshiana), English hawthorn,
salmonberry, rose spiraea, lady fern, and stinging nettle (Urtica dioica) (Wet.Iand 2022, in Appendix C).
Wetlands 12a and 12b are riverine wetlands associated with Stream 1, a Type F water. Wetland 12 is
mapped within a ravine that slopes from the east to west beneath a mature broadleaf maple (Acer
macrophyllum) canopy. Wet.Iand (2022, in Appendix C) describes the vegetation of Wetlands 12a and
12b as being dominated by black cottonwood, red osier dogwood, vine maple (Acer circinatum),
salmonberry, lady fern (Athyrium cyclosorum), and piggyback plant (Tolmiea menziesii).
4.3.1.2 Aquatic Species and Habitat
The aquatic study area (Figure 4.3-6):
101
• Extends 100 feet upstream and 300 feet downstream of each stream where the stream crosses
the footprint of the No Action Alternative, Alternatives 2, 3B, or 4.
• Includes the entire stretch of any stream paralleling the footprint of No Action Alternative,
Alternative 2, 3B, or 4 or stream habitat features within 200 feet of the edge of the footprint.
• Includes the segment of stream in which sound could travel in water (i.e. to the first bend in the
channel) for streams with habitat for ESA -listed species.
102
* ENE
Ari0'0
Alternative 3B is the only alternative with proposed in -water work. The aquatic study area for
Alternative 3B extends approximately 900 feet downstream and 670 feet upstream from where the
Alternative 3B Project footprint would cross the Duwamish River.
Sedimentation, turbidity, and pollution are additional impacts in the aquatic environment that would
extend out of the immediate project footprint. The aquatic study area for the No Action Alternative
(Figure 4.3-7) and for Alternatives 2 (Figure 4.3-8), 3B (Figure 4.3-9), and 4 (Figure 4.3-10 and Figure
4.3-11) do not account for pollutants such as 6PPD, microplastics, PBTs, and PAHs, among others, that
persist in the water column past anticipated distances for sediments to settle out.
A field reconnaissance survey was conducted to identify, map, and describe streams within the study
area. Two streams were identified within the 300-foot study areas of the Project design alternatives, see
Table 4.3-2.
Table 4.3-2 Burr nary of Streams within the Study Area
Stream
Name
Duwamish;
River
Stream 1
...............................................
a WAC 222-16-030
b TM C 18.44.040
`TMC 18.45.100.0
Type F
Water Typea Jurisdiction
of Tukwila
City of Tukwila
Buffer width (feet)
50b (Shoreline Residential)/
100b (Urban Conservancy without
Levees)
80`
No Action Alternative: The No Action Alternative includes the Duwamish River.
Design
Alternative with
Potential Direct
or Buffer Impacts
4
Alternative 2: Alternative 2 would not include any streams or the Duwamish River, see Figure 4.3-8.
Alternative 3B: The Duwamish River intersects the Project vicinity at Alternative 3B (Appendix C; WDFW
n.d.a). The aquatic study area for Alternative 3B extends approximately 900 feet downstream and 670
feet upstream from where the Alternative 3B Project footprint would cross the Duwamish River (Figure
4.3-9).
Alternative 4: Alternative 4 would intersect Stream 1 and the 200-foot buffer of the Duwamish River
(Figure 4.3-10 and Figure 4.3-11). Alternative 4 parallels the Duwamish River, but would not include in -
water work. The aquatic study area for Alternative 4 includes the section of the Duwamish River within
200 feet of the Alternative 4 footprint.
4.3.1.2.1 Stream and River Descriptions
Stream 1 is mapped by the City of Tukwila (City of Tukwila 2024 in Appendix C) as a Type F stream which
is defined as a perennial, fish bearing or a potentially fish bearing stream. This stream was not accessed
during field reconnaissance. The mapped stream flows through a narrow ravine with a mature broadleaf
maple canopy before flowing to Martin Luther King Jr Way South.
104
The Duwamish River is a Type S stream. Type S waters include all aquatic areas inventoried as
"shorelines of the state" under the County's Shoreline Master Program. The stretch of Duwamish River
adjacent to the Alternative 3B study area is located within the Duwamish Estuary, which includes the
extent of tidal influence from the mouth to river mile 12 (King County et.al. 2001). The Duwamish River
was historically, and is regularly, dredged to maintain a navigable waterway. This action, paired with the
tidally influenced water levels, have resulted in steep and unvegetated banks. Both banks are armored
with riprap within the study area and contain patches of unvegetated and subtidal substrates.
The Duwamish River is categorized as "Salmonid Rearing and Migration Only Habitat". Fourteen Priority
Species of fish are documented as occurring within the Duwamish River (WDFW n.d.a). Eight species of
anadromous salmonids have been noted in the Duwamish Estuary: Chinook salmon (Oncorhynchus
tshawytscha), coho salmon (O. kisutch), chum salmon (O. keta), and steelhead (O. mykiss) are common;
pink salmon (O. gorbuscha), sockeye salmon (O. nerka), sea -run cutthroat trout (O. clarkii clarkii), and
bull trout (Saivelinus confluentus) are rare (Williams et al. 2001). Bull trout, steelhead, and chinook are
federally threatened (WDFW n.d.a).
105
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4.3.1.2.2 Riparian Vegetation
The Natural Resource Conservation Service (NRCS) Ecological Site Characterization identified the Project
vicinity and surrounding areas as Puget Lowlands Forest or Puget Lowlands Wet Forest. Characteristic
riparian vegetation of Puget Sound Lowlands includes western hemlock (Tsuga heterophylla), Douglas fir
(Pseudotsuga menziesii), western red cedar (Thuja plicata), cottonwood (Populus balsamifera), willow
(Salixspp.), Pacific madrone (Arbutus menziesii), ocean spray (Holodiscus discolor), Oregon grape
(Mahonia spp.), Indian plum (Oemleria cerasiformis), and sword ferns (Polystichum munitum). In areas
with disturbance, minimal soil development, and a local seed source, red alder, big leaf maple (Acer
macrophylla), and vine maple (Acer circinatum) are present (Brennan 2007; USACE 2016).
Invasive species such as Himalayan blackberry, butterfly bush (Buddleja davidii), reed canarygrass, and
Japanese knotweed (Polygonum spp.) are common in disturbed areas (USACE 2016).
4.3.1.2.3 Aquatic Species
King County is home to approximately 50 species of freshwater fish (20 introduced), 12 species of
amphibians (one introduced), and eight reptiles (two introduced) (KCBR 2008). Of these species, 10
receive some type of federal or state protection due to being endangered, threatened, sensitive, a
candidate species, or some other official designation (USFWS 2024a; WDFW 2024d). Of the 10 species
listed under federal and/ or state protection (USFWS 2024b; WDFW 2024d), only the bull trout, chinook
salmon, and Puget Sound steelhead (Oncorhynchus mykiss) have designated critical habitat in the
Project vicinity (Figure 4.3-6; USFWS 2024a; NOAA 2024). Additionally, under the Magnuson Stevens
Act, the Duwamish River is Essential Fish Habitat (EFH) for groundfish, chinook, coho, and pink salmon
(NOAA 2024).
Table 4..3-.3 Animal species of concern with potential to be in or near the action area
Species
ESA Designation
Critical Habitat in
Project vicinity (Y/N)
State Status
Other
Designation
Reptiles
Northwestern pond
turtle
(Actinemys marmorata)
Proposed
Threatened
No
Endangered
None
Amphibians
Larch mountain
salamander (Plethodon
larselli)
None
No
Sensitive
None
Oregon spotted frog
(Rana pretiosa)
Threatened
No
Endangered
None
Western toad
(Anaxyrus boreas)
None
No
Candidate
None
Fishes
Bull trout
(Salvelinus confluentus)
Threatened
Yes
None
None
Puget Sound chinook
salmon (Oncorhynchus
tshawytscha)
Threatened
Yes
None
None
111
Species
ESA Designation
Critical Habitat in '
Project vicinity (Y/N)
State Status
Other
Designation
Puget Sound steelhead
(Oncorhynchus mykiss)
Threatened
Yes
None
None
River lamprey
(Lampetra ayresii)
None
No
Candidate
None
Olympic mudminnow
(Novumbra hubbsi)
None
No
Sensitive
None
Pygmy whitefish
(Prosopium coulteri)
None
No
Sensitive
None
4.3.1.2.3.1 Bull Trout
Bull trout (Saivelinus confluentus) in the conterminous United States were listed as threatened under
the ESA (64 FR 58910) in 1999. A final rule establishing critical habitat for bull trout was published in
2010 (75 FR 63898) and includes the Duwamish River in the proposed Project vicinity (Figure 4.3-6).
Historically, bull trout are known to occur in the Duwamish River; however, recent recorded
observations are limited (USFWS 2004).
Bull trout have multiple life history strategies and complex habitat requirements compared to other
salmonids (Rieman and McIntyre 1993). Their life history strategies include stream resident populations
(lives life in small headwater streams), fluvial populations (lives adult life in large rivers and spawns in
small tributary streams), lacustrine-adfluvial populations (lives adult life in lakes and spawns in small
tributary streams), and anadromous populations (lives adult life in marine waters and spawns in
freshwater) (McPhail and Baxter 1996). The Puget Sound Region supports a mix of all four life history
forms with the anadromous life history form being unique to the region (USFWS 2015).
StreamNet identifies the portion of the Duwamish within the aquatic study area as "migration only"
habitat for bull trout (PSMFC 2024). Bull trout have been identified in the Green River as far upriver as
RM 41, and it is presumed they utilize the river up to RM 61 before reaching a barrier that blocks further
passage. They have also been documented in the Duwamish River in recent decades (three occurrences
in April -May and two occurrences in August -September) as far downriver as RM 1 (USFWS 2004).
Despite these occurrences, it is likely the Duwamish does not provide suitable habitat for bull trout.
Lack of complex habitat and elevated temperatures are likely to limit bull trout presence in the study
area. Bull trout require habitats with cold water temperatures and tributary connectivity and
complexity. Bull trout spawn from August through November, often in waters below 9°C (48.2°F)
(McPhail and Baxter 1996). Bull trout require complex forms of cover such as large woody debris,
undercut banks, boulders and pools, for all life history stages (USFWS 2004). Habitat degradation has
affected not only bull trout, but also important prey species such as juvenile salmon, surf smelt
(Hypomesus pretiosus), sandlance (Ammodytes hexapterus), and herring (Clupea pallasii). Puget Sound's
shoreline has been grossly altered, and nearly 100% of the Duwamish estuary has been modified by
some type of armoring (USFWS 2015). The U.S. Geological Survey Duwamish River gage at the Golf
Course in Tukwila (Station ID: 12113390), approximately 1.7 miles upstream of Alternative 3B, has
recorded temperatures from as low as 3.62C (38.482F) to as high as 18.72C (65.662F) between August
2016 and June 2017 (USGS 2024).
112
4.3.1.2.3.2 Steelhead
The Puget Sound Distinct Population Segment (DPS) of steelhead (Oncorhynchus mykiss) was listed as
threatened under the ESA in 2007 (72 FR 26722) and includes the population that inhabits the
Duwamish River. Critical habitat was designated for Puget Sound steelhead in 2016 (81 FR 9251) and
includes the section of the Duwamish River in the Project vicinity.
The Green/Duwamish River supports both winter and summer run types of steelhead. StreamNet
identifies the portion of the Duwamish within the aquatic study area as "migration only" habitat for
both winter and summer steelhead (PSMFC 2024). Winter run steelhead, also known as ocean -maturing
steelhead, are naturally produced. Summer run steelhead, also known as stream maturing steelhead,
are of hatchery origin (Kerwin and Nelson 2000). While winter steelhead can remain in freshwater as a
resident rainbow trout or migrate to sea, the majority of juvenile winter steelhead migrate to saltwater.
Steelhead in the Duwamish/Green River typically spend two years in freshwater, but may spend one to
three years (Kerwin and Nelson 2000).
The key difference between winter and summer run steelhead is their level of sexual maturation prior to
entering freshwater entry (Burgner et al. 1992, Smith 1969). Winter steelhead typically enter the river in
December in a mature reproductive state and spawn from February through May. Summer steelhead
enter freshwater at an earlier stage of maturation. They generally run May through October and spawn
February through April, although exact timing is unknown (Kerwin and Nelson 2000).
4.3.1.2.3.3 Chinook
The Puget Sound Evolutionary Significant Unit (ESU) of Chinook salmon (Oncorhynchus tshawytscha)
was listed as threatened under the ESA in 1999 (64 FR 14308) for the first time and reaffirmed in 2005
(70 FR 37160). Critical habitat was designated in 2005 (70 FR 52629) and includes the Duwamish River in
the Project vicinity (Figure 4.3-6). Historically, spring Chinook and summer/fall Chinook inhabited the
Duwamish/Green River. Spring Chinook either return in numbers so low they are not detectable, or they
have been extirpated from the site (Kerwin and Nelson 2000). Therefore, summer/fall Chinook are the
only run -type currently found in the Duwamish/Green River.
While some Chinook salmon may reside in freshwater for an entire year after emerging, Puget Sound
Chinook typically leave the freshwater environment within the first year, favoring the protected estuary
and nearshore habitats (Kerwin and Nelson 2000). It is unknown how long the outmigration of Chinook
salmon fry takes, but they may inhabit the shallow side margins, side channels, and side sloughs for up
to two months. Chinook from the Duwamish/Green River commonly spend two to four years at sea;
however, they may spend anywhere from one to six years at sea (Kerwin and Nelson 2000).
Summer/fall Chinook spawn September through December primarily between RM 24.0 and RM 61.0 of
the Green River. It is estimated they migrate through the Duwamish River from mid -June through
October. Like all salmonid species, Chinook salmon need adequate flow and water quality, spawning
riffles and pools, a functional riparian zone, and stable upland conditions (Kerwin and Nelson 2000).
Chinook typically spawn in higher velocity areas with larger gravels than areas used by other salmon
species.
StreamNet identifies the portion of the Duwamish within the aquatic study area as "rearing and
migration" habitat for fall chinook (PSMFC 2024). This reach of the Duwamish is tidally influenced and is
brackish. Additionally, from RM 11 to RM 5.2 of the Duwamish, which includes this study area, the
113
shoreline is heavily modified and hardened, consisting of bulkheads, riprap, and docks, thereby making
it unsuitable habitat for spawning chinook.
4.3.1.3 Terrestrial species and Habitat
The terrestrial study area includes the Project footprint of each alternative plus a 200-foot buffer of the
Project footprint (Figure 4.3-12, Figure 4.3-13, Figure 4.3-14, Figure 4.3-15, and Figure 4.3-16). The
buffer accounts for Project activities that could affect vegetation cover and habitat quality for terrestrial
wildlife outside of the Project footprint. Most impacts to terrestrial species and habitat would take place
within the 200-foot buffer. However, the farthest -reaching impact of the Project to terrestrial wildlife is
the in -air noise caused by construction of the selected Alternative. Because the Project is still in early
planning stages, it is unknown what methods of construction will occur or what equipment will be used.
To be conservative, the area of in- air noise impact was calculated for a range of construction equipment
(Table 4.3-11). In -air noise impacts in the terrestrial environment were considered outward 2.38 miles
from the Project vicinity (Figure 4.3-17).
Terrestrial habitat is limited within the proposed Project vicinity due to the effects of development. The
Project vicinity is surrounded by industrial, commercial, and residential buildings and is in the vicinity of
Interstate 5 and SR 599. Most terrestrial habitat within the Project vicinity is located in fragmented
segments adjoining roads and rivers or in public open spaces. In 2017, the landscape of the city of
Tukwila was comprised of 23% tree canopy (20% overhanging impervious surfaces), 20% non -canopy
vegetation, 5% soil/dry vegetation, 48% impervious surfaces, and 5% water (City 2018). Based on the
2020 US Census, the city of Tukwila has an estimated population of 21,135 people with an average
population density of 2,373 people per square mile (USCB 2023a) making the average daytime
background noise levels exclusive of traffic equal to 50 dBA. The average background noise for the city
ranges between 57-67 dB (Noise Map 2024). The area surrounding the proposed Project vicinity consists
of primarily impervious surfaces making it a "hard site", meaning it does not provide noise attenuation
(WSDOT 2023).
4.3.1..3.1. Na Action Alternative
There are no terrestrial Priority Habitats or species (WDFW n.d.a) or Environmentally Critical Areas (TMC
18.45) located within this alternative. Existing conditions within the Alternative 2 footprint are currently
primarily covered with grass/low-lying vegetation and trees. Impervious surfaces occupy 74.37 acres, or
52.42%, of the Project footprint. The No Action Alternative would not increase the coverage of
impervious surfaces because there is no new construction for this alternative.
114
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The 200-foot buffer surrounding the No Action Alternative footprint is comprised of primarily
impervious surfaces (74.37 acres) followed by a combination of grass/low-lying vegetation (34.56 acres)
and trees (22.24 acres) (Table 4.3-4). The No Action Alternative does not have a project area footprint
because it is already constructed.
Table 4.3-4 Landcover classification of the No Action Alternative
Landcover Class
Area within Project
Footprint (acres)
Area within 200'
buffer (acres)
Total Area (acres)
Bare Soil
-
6.31
6.31
Grass/Low-Lying Vegetation
-
34.56
34.56
Impervious Surfaces
-
74.37
74.37
Open Water
-
4.38
4.38
Tree Canopy
-
22.24
22.24
Unclassified
(Unincorporated King
County)
-
-
-
Total
-
141.86
141.86
4.3.1..3.2. Alternative 2.
Aside from the wetlands mentioned in Section 4.3.1.1, there are no terrestrial Priority Habitats and
Species (WDFW n.d.a) or Environmentally Critical Areas (TMC 18.45) located within this alternative.
Existing conditions within the Alternative 2 footprint are currently primarily covered with grass/low-lying
vegetation and trees. Impervious surfaces occupy 2.98 acres, or 10.6%, of the Project footprint.
Alternative 2 would increase the coverage of impervious surfaces to approximately 28.18 acres, which is
an additional 25.2 acres of new impervious surfaces.
116
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acres) followed by a combination of grass/low-lying vegetation (9.79 acres) and trees (8.13 acres) (Table
4.3-5). The buffer surrounding the alternative footprint is not expected to be converted to impervious
surfaces based on current Project details; however, it could be impacted during construction activities.
Table 4..3-5 Landcover classification of Alternative 2
Landcover Class
Area within Project
Footprint (acres)
Area within 200'
buffer (acres)
Total Area (acres)
Bare Soil
2.23
3.19
5.42
Grass/Low-Lying Vegetation
11.84
9.79
21.64
Impervious Surfaces
2.98
20.21
23.20
Open Water
0.15
0.00
0.15
Tree Canopy
10.75
8.13
18.88
Unclassified
(Unincorporated King
County)
0.23
1.55
1.78
Total
28.18
42.88
71.06
4.3.1..3.3 Alternative 3B
There are no terrestrial Priority Habitats and Species (WDFW n.d.a) or Environmentally Critical Areas
(TMC 18.45) located within this alternative. Existing conditions within the Alternative 3B footprint have
very little vegetation. Impervious surfaces occupy 2.19 acres, or 73.49%, of the Project footprint.
Alternative 3B would increase the coverage of impervious surfaces to approximately 2.87 acres which is
an additional 0.68 acres of new impervious surfaces.
The 200-foot buffer surrounding the Alternative 3B footprint is primarily impervious surfaces (18.64
acres) followed by a combination of trees (4.73 acres) and open water (3.59 acres) (Table 4.3-6). The
buffer surrounding the alternative footprint is not expected to be converted to impervious surfaces
based on current Project details; however, it could be impacted during construction activities.
Table 4..3-6 Landcover classification of Alternative .3B
Landcover Class
Area within Project
Footprint (acres)
Area within 200'
buffer (acres)
Total Area (acres)
Bare Soil
0.02
0.10
0.12
Grass/Low-Lying Vegetation
0.14
2.96
3.10
Impervious Surfaces
2.19
18.64
20.83
Open Water
0.11
3.59
3.71
Tree Canopy
0.41
4.73
5.14
Unclassified
(Unincorporated King
County)
0.00
0.00
0.00
Total
2.87
30.03
32.89
118
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4.3.1..3.4 Alternative 4
The PHS web mapper identified a biodiversity area and corridor that intersects with the proposed
alternative vicinity. The East Duwamish Greenbelt -Seattle would intersect the northern section of
Alternative 4. The greenbelt offers steep, west facing slopes and is composed of stands of deciduous and
mixed conifer -deciduous trees with diameters ranging from five to 20 inches. Wetlands, seeps, snags,
downed logs, talus, and shrubs are also present. Osprey have been observed nesting in the area near
Martin Luther King Way (WDFW n.d.a).
Existing conditions within the Alternative 4 footprint are a mix of unclassified land cover, tree canopy,
and impervious surfaces. Impervious surfaces occupy 1.73 acres, or 26.25%, of the Project footprint
(Table 4.3-7). Alternative 4 would increase the coverage of impervious surfaces to approximately 6.59
acres which is an additional 4.86 acres of new impervious surfaces.
The 200-foot buffer surrounding the Alternative 4 footprint is primarily impervious surfaces (18.37
acres) followed by a combination of trees (11.89 acres), grass/low-lying vegetation (7.63 acres), and
unclassified land (9.58 acres). The buffer surrounding the alternative footprint is not expected to be
converted to impervious surfaces based on current Project details; however, it could be impacted during
construction activities.
Table 4..3-7 Landcover classification of Alternative 4
Landcover Class
Area within Project
Footprint (acres)
Area within 200'
buffer (acres)
Total Area (acres)
Bare Soil
0.03
1.00
1.03
Grass/Low-Lying Vegetation
0.53
7.63
8.15
Impervious Surfaces
1.73
18.37
20.10
Open Water
0.00
1.79
1.79
Tree Canopy
1.84
11.89
13.72
Unclassified
(Unincorporated King
County)
2.46
9.58
12.05
Total
6.59
50.25
56.84
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4.3.1.3.5 Terrestrial Fauna
In addition to abundant plant life, King County is also home to approximately 221 species of birds (five
introduced), and 69 species of mammals (eight introduced) (KCBR 2008). Of these species, 35 receive
some type of federal or state protection due to being endangered, threatened, sensitive, a candidate
species, or some other official designation (USFWS 2024a; WDFW 2024d). Of the 34 terrestrial species
listed under federal and/ or state protection (USFWS 2024a; WDFW 2024d), none have designated
critical habitat in the Project vicinity (USFWS 2024a).
Table 4..3-8 Animal species of concern with potential to be in or near the action area
Species
ESA Designation
Critical Habitat in
Project vicinity (Y/N)
State Status
Other
Designation
Mammals
Wolverine
(Gulo gulo luscus)
Threatened
No
Candidate
None
Townsend's Big -eared
Bat
(Corynorhinus
townsendii)
None
No
Candidate
None
Cascade Red Fox
(Vulpes vulpes
cascadensis)
None
No
Endangered
None
Fisher
(Pekania pennanti)
None
No
Endangered
None
Birds
Marbled Murrelet
(Brachyramphus
marmoratus)
Threatened
No
Endangered
None
Yellow -billed Cuckoo
(Coccyzus americanus)
Threatened
No
Endangered
None
Bald Eagle (Haliaeetus
leucaocephalus)
None
No
None
Eagle Act;
Migratory
Golden Eagle
(Aquila chrysaetos)
None
No
None
Eagle Act;
Migratory
Ancient Murrelet
(Synthliboramphus
antiquus)
None
No
None
BCC;
Migratory
Black Swift
(Cypseloides niger)
None
No
None
BCC;
Migratory
Black Turnstone
(Arenaria
melanocephala)
None
No
None
BCC;
Migratory
California Gull
(Larus californicus)
None
No
None
BCC;
Migratory
Clark's Grebe
(Aechmophorus clarkia)
None
No
None
BCC;
Migratory
124
Species
ESA Designation
Critical Habitat in
Project vicinity (Y/N)
State Status
Other
Designation
Evening Grosbeak
(Coccothraustes
vespertinus)
None
No
None
BCC;
Migratory
Lesser Yellowlegs
(Tringa flavipes)
None
No
None
BCC;
Migratory
Marbled Godwit
(Limosa fedoa)
None
No
None
BCC;
Migratory
Olive -sided Flycatcher
(Contopus cooperi)
None
No
None
BCC;
Migratory
Oregon Vesper Sparrow
(Pooecetes gramineus
affinis)
None
No
None
BCC-BCR;
Migratory
Chestnut -backed
Chickadee (Poecile
rufescens rufescens)
None
No
None
BCC-BCR;
Migratory
Rufous Hummingbird
(Selasphorus rufus)
None
No
None
BCC;
Migratory
Short -billed Dowitcher
(Limnodromus griseus)
None
No
None
BCC;
Migratory
Western Grebe
(Aechmophorus
occidentalis)
None
No
Candidate
BCC;
Migratory
Common Loon
(Gavia immer)
None
No
Sensitive
None
Northern Goshawk
(Accipiter gentilis)
None
No
Candidate
None
Northern Spotted Owl
(Strix occidentalis
caurina)
Threatened
No
Endangered
None
Black -backed
Woodpecker
(Picoides arcticus)
None
No
Candidate
None
Invertebrates
Blue -gray Taildropper
(Prophysaon coeruleum)
None
No
Candidate
None
Monarch Butterfly
(Danaus plexippus)
Candidate
No
None
None
Pacific Clubtail
(Phanogomphus kurilis)
None
No
Candidate
None
Beller's Ground Beetle
(Agonum belleri)
None
No
Candidate
None
Hatch's Click Beetle
(Eanus hatchii)
None
No
Candidate
None
Western Bumble Bee
(Bombus occidentalis)
Candidate
No
Candidate
None
125
Species
ESA Designation
Critical Habitat in
Project vicinity (Y/N)
State Status
Other
Designation
Johnson's Hairstreak
(Callophrys johnsonii)
None
No
Candidate
None
Valley Silverspot
(Argynnis zerene
bremnerii)
None
No
Candidate
None
BCC: Bird of Conservation Concern throughout its range
BCC-BCR: Bird of Conservation Concern in particular Bird Conservation Regions
The amount of development and human interaction in and around the Project vicinity has decreased the
likelihood of many federally and state -protected species residing in the area. The species listed in Table
4.3-8 have been identified as occurring or potentially occurring in King County. However, review of state
agency databases (WDFW n.d.a) indicate the following species do not occur and/or suitable habitat does
not occur in the Project vicinity: wolverine (Gulo gulo Iuscus), fisher (Pekania pennanti), Cascade red fox
(Vulpes vulpes cascadensis), northwestern pond turtle (Actinemys marmorata), Oregon spotted frog
(Rana pretiosa), and northern spotted owl (Strix occidentalis caurina).
Federal and state endangered and threatened species that are most likely to occur in the project study
area will be discussed further in this document; however, candidate and sensitive species will not be
discussed further.
4.3.1.3.5.1 Oregon Vesper Sparrow
The Oregon vesper sparrow (Pooecetes gramineus affinis) was listed as endangered in the state of
Washington in February 2021 (Altman et.al. 2020). This species is located in Washington primarily from
April through late September. In the winter, they migrate to central and southern California. The
Washington population of the Oregon vesper sparrow is estimated to be 300 birds with 90% of those
birds residing in the Puget lowlands, mostly on Joint Base Lewis McCord (JBLM). Outside of JBLM there
are small populations located on Tenalquot Prairie Preserve, private pastureland between Tenalquot
Prairie and JBLM, San Juan Island, Sanderson Field/Shelton Airport, Mima Mounds Natural Area
Preserve, and on islands in the Columbia River (Altman et.al. 2020).
Vesper sparrows are a large, ground nesting sparrow that breed in herbaceous -dominated, open upland
landscapes. Common breeding areas include prairie, savannahs, pastures, airfields, Christmas tree
farms, and vegetated dredged -material sites (Altman et.al. 2020). Vesper sparrows tend to avoid wet
areas and sites with tall, dense herbaceous vegetation. They eat a wide variety of insects supplemented
with seeds and prefer to forage on a mix of bare ground and in short vegetation (WDFW n.d.b).
The Project vicinity, which encompasses each of the Project alternative footprints and the surrounding
area, largely consists of unforested, developed land, and there are no records of Oregon vesper
sparrows in the area (WDFW n.d.b). The remaining breeding population is primarily found in Thurston
and Pierce counties in prairies and around airports, especially on Joint -Base Lewis McChord.
It is unlikely the Oregon vesper sparrow is present in the Project vicinity. Alternative 2 is the alternative
that would most likely contain suitable habitat for the Oregon vesper sparrow. It contains 11.84 acres of
low-lying vegetation and/or grass that could provide suitable habitat for the Oregon vesper sparrow;
however, there is an active gun range within the proposed Alternative 2 footprint, and the footprint
abuts the current BNSF intermodal facility. The amount of human disturbance in Alternative 2 would
126
make the area unsuitable habitat. Alternative 3B and Alternative 4 do not contain suitable habitat for
the Oregon vesper sparrow. There is very little contiguous open space or vegetation. The existing
vegetation is primarily comprised of tall trees, which are not preferred by the Oregon vesper sparrow.
Because none of the alternatives meet the habitat requirements for this species and the species is not
known to occur in King County, it will not be considered further in this document.
4.3.1.3.5.2 Marbled Murrelet
The marbled murrelet (Brachyramphus marmoratus) was listed as threatened under the ESA in 1992 (57
FR 45328) and by the Washington Fish and Wildlife Commission in 1993 (Desimone 2016). Critical
habitat was designated for the marbled murrelet in 1996 (FR 26256) and revised in 2011 (76 FR 61599).
The Project vicinity is not located within designated critical habitat; however, designated critical habitat
occurs within King County approximately 30 miles east of the Project vicinity in the forested areas of the
central Cascade Mountain range and Olympic Mountains. Marbled murrelets are not a common species
in Washington, but Puget Sound and Strait of Juan de Fuca are home to the greatest number of marbled
murrelets in the state (WDFW n.d.c).
Marbled murrelets are a small, diving seabird that forage in marine waters and nest in old growth
forests. The marbled murrelet spends approximately 90% of its time on the ocean in waters less than
100 feet deep resting and feeding on a variety of marine prey such as crustaceans and small schooling
fish (USFWS 2024a). Marbled murrelets typically nest in old growth forests, preferring large
unfragmented stands with large trees such as western hemlock, Sitka spruce, Douglas fir, and western
redcedar trees. During breeding season, from April to mid -September, marbled murrelets in Washington
commute an average of 32 miles (range 10.4-90.2 miles) between their nests and foraging habitat
(Lorenz et al. 2016).
The Project vicinity largely consists of unforested, developed land and there are no records of marbled
murrelets in the area (WDFW n.d.c). The Project vicinity does not contain suitable nesting habitat for the
marbled murrelet and is approximately five miles east of marine habitat that is suitable for foraging.
Marbled murrelets are not known to occur in the Project vicinity; however, a marbled murrelet could fly
through the area due to their tendency to transit long distances between their nesting sites and foraging
grounds.
4.3.1.3.6 Terrestrial Vegetation
There are approximately 1,249 (383 introduced) vascular plants in King County (KCBR 2008). Of these
species, 34 are listed as a species of concern at either the state or federal level (Table 4.3-9).
Table 4..3-9 Vascular plant species of concern with potential to be in the action area
Species
Common Name
State Status
Federal Status
Actaea elata var. elata
Tall bugbane
Sensitive
None
Arenaria paludicola
Swamp sandwort
Extirpated
Endangered
Botrychium ascendens
Triangular -lobed
moonwort
Sensitive
None
Botrychium hesperium
Western moonwort
Sensitive
None
Botrychium pedunculosum
Stalked moonwort
Threatened
None
Brodiaea rosea ssp. rosea
Harvest brodiaea
Sensitive
None
Campanula lasiocarpa
Alaska harebell
Sensitive
None
127
Species
Common Name
State Status
Federal Status
Carex pauciflora
Few -flowered sedge
Sensitive
None
Carexrostrata (sensustricto)
Northern beaked sedge
Sensitive
None
Carexstylosa
Long -styled sedge
Sensitive
None
Cassiope lycopodioides
Clubmoss mountain-
heather
Sensitive
None
Castilleja levisecta
Golden paintbrush
Threatened
Threatened
(Proposed
Delisting)
Chrysolepis chrysophylla var.
chrysophylla
Golden chinquapin
Sensitive
None
Cirsium remotifolium var.
remotifolium
Weak thistle
Endangered
None
Coptis asplenifolia
Spleenwort-leaved
goldthread
Sensitive
None
Dendrolycopodium dendroideum
Tree clubmoss
Sensitive
None
Eutrochium maculatum var. bruneri
Spotted Joe-pye weed
Sensitive
None
Fritillaria camschatcensis
Kamchatka fritillary
Sensitive
None
Gentiana douglasiana
Swamp gentian
Sensitive
None
Heterotheca oregona
Oregon goldenweed
Sensitive
None
Hypericum majus
Large St. Johns' -wort
Sensitive
None
Lathyrus vestitus var. ochropetalus
Pacific peavine
Endangered
None
Lobelia dortmanna
Water lobelia
Sensitive
None
Lycopodiella inundata
Northern bog clubmoss
Sensitive
None
Lycopodium lagopus
One -cone clubmoss
Sensitive
None
Meconella oregano
White meconella
Endangered
None
Montia diffusa
Branched montia
Sensitive
None
Nuttallanthus canadensis
Old field blue toadflax
Sensitive
None
Nuttallanthus texanus
Texas blue toadflax
Sensitive
None
Pellaea breweri
Brewer's cliffbrake
Sensitive
None
Pinus albicaulis
Whitebark pine
Sensitive
Proposed
Threatened
Platanthera chorisiana
Choriso's bog -orchid
Sensitive
None
Sericocarpus rigidus
Columbia white -topped
aster
Sensitive
None
Utricularia intermedia
Flat -leaved bladderwort
Sensitive
None
The amount of development and human interaction in and around the Project vicinity has decreased the
likelihood of many federally and state -protected plant species residing in the area. Endangered and
threatened species will be discussed further in this document; however, candidate and sensitive species
will not be discussed further.
4.3.1.3.6.1 Swamp sandwort
The last record of swamp sandwort (Arenaria paludicola) in Washington state was in Tacoma at "Flett's
Creek" in 1896 (Fertig 2024). Development and competition with invasive plants, such as reed canary
128
grass , have significantly reduced the amount of available habitat (Fertig 2024). Due to its status as
"extirpated", this plant will not be considered further.
4.3.1.3.6.2 Stalked moonwort
Stalked moonwort (Botrychium pedunculosum) is typically found in moist or dry meadows, springs,
coniferous forests, and forest edges at elevations between 500-1325 m (1640-4340 ft). It is commonly
found in association with lodgepole pine (Pinus contorta), Engelmann spruce (Picea engelmannii), red
cedar (Thuja plicata), mosses, and other moonworts (Botrychium spp.). The Project vicinity does not
meet the habitat requirements for this plant, so it will not be considered further in this document (Fertig
2021).
4.3.1.3.6.3 Golden paintbrush
Golden paintbrush (Castilleja Ievisecta) populations are found in open, undulating remnant prairies
dominated by Roemer's fescue (Festuca roemeri) and Red fescue (F. rubra) on gravelly or clayey
outwash (Fertig 2021). While extant populations exist in Washington, it is considered extirpated in King
County (Fertig 2021). Therefore, it will not be considered further in this document.
4.3.1.3.6.4 Weak Thistle
Weak Thistle (Cirsium remotifolium var. remotifolium) can be found in moist meadows, streamsides,
rock outcrops, prairies, and transition zones between forests and meadows. It is typically found at
elevations between 15-915 m (50-3000 ft). Historical populations were found in the Puget Trough
Ecoregion in King County, but it is likely those populations are now extirpated (Fertig 2021). Therefore, it
will not be considered further in this document.
4.3.1.3.6.5 Pacific peavine
Pacific peavine (Lathyrus vestitus var. ochropetalus) is known to occur in King County. It is typically
found in dry, open to wooded areas, forest edges, and roadsides, or near or within historical prairies at
elevations between 75-170 m (250-565 ft). It is commonly found with young Douglas -fir (Pseudotsuga
menziesii), black raspberry (Rubus Ieucodermis), and garden vetch (Vicia sativa) (Fertig 2021).
4.3.1.3.6.6 White meconella
White meconella (Meconella oregano) is typically found in open grassland, but is sometimes found
within a mosaic of forest and grassland. It can be found on gradual to 100% slopes at elevations that
range between 20-90 meters (60-620 feet). There has not been a documented occurrence in King
County in over 40 years (Fertig 2021).
4.3.1.3.6.7 Whitebark pine
Whitebark pine (Pinus albicaulis) is rarely found at lower elevations. In Washington, it is primarily found
in subalpine areas of higher mountains at elevations between 1280-2430 meters (4200-7975 feet). It is
often associated with Engelmann spruce (Picea engelmannii) and subalpine fir (Abies Iasiocarpa). The
Project vicinity does not meet the habitat requirements for this plant, so it will not be considered further
in this document (Fertig 2021).
4.3.2 Relevant Plans Policies and Regulations
The relevant plans, policies, regulations, and guidance consulted when analyzing the potential impacts
of the proposed Alternatives are described in Table 4.3-10.
129
Laws and Ftegulatioris
Description,
Federal
Endangered Species Act (ESA,l6USCl5]let
seq.)
Ensures that the proposed action ionot likely to
jeopardize existence ofany listed threatened or
endangered animal species orresult inadverse
modification ofdesignated critical habitat.
Magnuson -Stevens Fishery Conservation and
Management Act, asamended bythe Sustainable
Fisheries Act oflyy6(Public Law lO4'267)
The primary law that governs marine fisheries
management inU.S.federal waters.
Migratory Bird Treaty Act (MBl7\)
Ensures ouotainabiUtyofpopulations of all
protected migratory bird species. Prohibits the
take (including killing, capturing, selling, trading,
and transport) of protected migratory bird
species without prior authorization bythe
Department ofInterior U.S. Fish and Wildlife
Service.
Bald and Golden Eagle Protection Act (BGEPA)
Ensures the protection of bald and golden eagles
including their parts (feathers), nests, and eggs.
Clean Water Act
The principal statute for water quality protection.
Provides standards for the propagation and
protection offish, shellfish, and wildlife.
State
Washington State Growth Management Act (RCVV
]6.70A)
Requires all cities and counties to designate
natural resources lands and critical areas and
identify steps to preserve them, including fish and
wildlife habitat conservation areas.
Washington State Shoreline Management Act
(RCVVyO.5O)
Requires all counties and most towns and cities
with shorelines to develop and implement
Shoreline Master Programs. One intention of the
Act is to protect shoreline natural resources
against adverse environmental impacts, including
wildlife and aquatic habitats.
Washington State Water Pollution Control Act
(90.48 RCVV)
Ensures the purity ofall waters ofthe state is
consistent with public health and public
enjoyment including the propagation and
protection ofwild life, birds, game, fish and other
aquatic life.
Washington State Department of Fish and
Wildlife Hydraulic Permit Approval (VVAC22O'
660)
The Hydraulic Permit Approval (HAA) is intended
toensure construction ofwork that uses, diverts,
obstructs, orchanges the natural flow orbed of
any salt orfresh waters ofthe state isdone ina
manner that protects fish life.
Washington State Department ofEcology NPDES
Permit Program
Covers discharge to surface waters.
Salmon Recovery Act (RCVV 77.85)
Provides a planning and implementation process
that iofocused onfish habitat.
130
Laws and Regulations
Description
RCW 77.55 Construction Projects in State Waters
Requires a Hydraulic Project Approval (HPA)
Permit to ensure fish protection during hydraulic
projects.
Local
City of Tukwila Comprehensive Plan
Tukwila's Comprehensive Plan is a long-term
guiding document or "blueprint" that explains
the community's values and priorities to guide
growth and development.
Tukwila Municipal Code (TMC) Chapter 18.45
The purpose of TMC Chapter 18.45 is to protect
the environment, human life and property; to
designate and classify ecologically critical areas
including but not limited to regulated wetlands
and watercourses and geologically hazardous
areas and to protect these critical areas and their
functions while also allowing for reasonable use
of public and private property
King County Critical Areas Ordinance (King County
Code [KCC] 21A.24)
This ordinance was developed under the
directives of the GMA to designate and protect
critical areas and to assist in conserving the value
of property, safeguarding the public welfare, and
providing protection for these areas.
4.3.3 Methodology
A desktop review was conducted using available information on existing and historic plant and animal
species and their habitat in the Project vicinity and surrounding area. Impacts to plants and animals from
the proposed Project development have been evaluated and weighed to determine whether the
proposed Project would have significant impacts affecting on -site wildlife habitat, native plant
communities, priority species, designated locally important species, or listed species (federal and state).
Critical areas and their buffers, defined by T.M.0 18.06.182 were given special consideration and
identified using the Tukwila iMap tool. Critical areas defined as "wetlands, watercourses, areas of
potential geologic instability (other than Class I areas), abandoned coal mine areas, fish, and wildlife
habitat conservation areas, and special flood hazard areas" and their buffers, defined as "an area lying
adjacent to, but outside a critical area whose function is to protect, critical areas from the potential
adverse impacts of development, land use, or other activities. A wetland or watercourse critical area
buffer also provides critical habitat value, bank stabilization, or water overflow area functions."
HDR conducted field reconnaissance and prepared a technical memorandum, Wetland and Streams
Technical Memorandum (Appendix C) that identified and documented existing wetlands and streams
along and near the No Action Alternative, and Alternatives 2, 3B, and 4. This report informs the wetland
section of this chapter.
The Washington Department of Fish and Wildlife (WDFW) manages the Priority Habitats and Species
Program (PHS)(WDFW n.d.a) which is a tool to inform landowners, local governments and other
stakeholders of important fish and wildlife information from resource experts. The PHS Web Application
131
was also used to determine which priority habitat and species are likely to be found in the Project
vicinity (WDFW n.d.a).
The PHS Statewide List and Distribution by County and the Washington Natural Heritage Program list of
vascular plant species of conservation concern were used to determine plant and animal state -listed
species of concern in King County that may have potential to be in the study area (Table 4.3-8 and Table
4.3-9; WDFW n.d.d; DNR 2024e).
The US Fish and Wildlife Service (USFWS) Information for Planning and Consultation (IPaC) tool and the
National Oceanic Atmospheric administration (NOAA) Fisheries Species and Habitat App were used to
determine which species and habitat in the Project vicinity receive federal protection (Table 4.3-8;
USFWS 2024b; NOAA 2024).
4.3.3.1 Noise Assessment Methodology
The effects of noise were also considered for their potential impacts to aquatic and terrestrial species.
Due to the uncertainty of equipment used, terrestrial action areas were calculated for a range of
construction equipment that could potentially be used for the Project. Values for specific equipment can
be found in the Washington Department of Transportation Biological Assessment Preparation Manual
Chapter 7, Table 7-4. To determine the distance the noise generated by construction equipment
attenuates, the following equation is used:
Equation 4.3-1
Construction Noise —Background Noise in dBA
D=Do x10' a
Where D = the distance from the noise source
Do = the reference measurement difference (50 feet)
Construction Noise = varies between 60-105 dB
Background noise = 57 (range of 57-67 dB)
a = 20 for hard sites. For point source noise, a spherical spreading loss model is used. These
alpha (a) values assume a 6.0 dBA reduction per doubling distance over hard ground.
If multiple pieces of equipment are used simultaneously, these values need to be re-evaluated.
Additionally, if a nest site or other special site is discovered, the values will be to be adjusted based on
distance to the special site.
Table 4..3-11 Terrestrial action area for a range of sound produced by construction equipment
Construction Equipment
(dB)
Action Area
(feet)
Action Area
(miles)
60
71
0.01
70
223
0.04
80
706
0.13
90
2233
0.42
97
5000
0.95
132
Construction Equipment
(dB)
Action Area
(feet)
Action Area
(miles)
100
7063
1.34
105
12559
2.38
Potential noise impacts affect both the aquatic and terrestrial environment. Noise impacts have the
potential to affect threatened and endangered species including the marbled murrelet. They could also
impact other sensitive species that may be found in the area including eagles and migratory birds. If a
bald eagle nest is observed, USFWS will review construction activities within a 660-foot buffer
management zone.
4.3.3.2 Impact Descriptions
The impacts of each alternative on plants and animals were determined by the location of the
permanent footprint of the alternative as well as impacts that extended beyond the project footprint
including noise, turbidity, and pollution. Potential impacts to plants and animals are discussed
quantitatively where information is available (e.g. acreage of wetlands affected or area of new
impervious surfaces), but are otherwise discussed qualitatively. The potential impacts to Wetlands,
Aquatic Species and Habitat, and Terrestrial Species and Habitat are evaluated by using the definitions in
Table 4.3-12.
Table 4..3-12 Impact Magnitude and Description
Magnitude of Impact
Description
No Impact
The proposed Project would be fully consistent with the intent of applicable
plans and policies for wetlands, aquatic species and habitat, or terrestrial
species and habitat plans.
Minor
The proposed Project would result in short-term temporary impacts, or minimal
long-term impacts to wetlands, aquatic species and habitat, or terrestrial
species and habitat.
Moderate
The proposed Project would result in long-term or permanent impacts to
wetlands, aquatic species and habitat, or terrestrial species and habitat, but
mitigation can be applied to reduce the impact to be less than significant.
Significant
The proposed Project would cause long-term, permanent, or irreversible
inconsistencies with applicable plans and policies or the zoning codes pertaining
to wetlands, aquatic species and habitat, or terrestrial species and habitat.
An unavoidable significant adverse impact would occur if regulatory requirements, design measures, or
mitigation measures would not address the potential impacts. The temporary and long-term
construction impacts and operation impacts are analyzed in the following subsections.
4.3.4 Impacts Analysis
This subsection addresses temporary and long-term impacts from construction and operation of each
alternative on wetlands and wetland buffers, aquatic species and habitats, and terrestrial species and
habitats. The location and final design of the preferred alternative, construction footprint and methods,
and Best Management Practices (BMPs) utilized during construction will determine the actual impacts to
resources and their buffers.
133
Wetlands
Construction impacts to wetlands will occur where features such as roads overlap with wetlands or
wetland buffers. Construction activities that fill, excavate, or clear vegetation in wetlands or wetland
buffers diminish wetland functions through loss of area, hydrologic changes, or long-term vegetation
changes. Elevated structures may limit the amount of sunlight and precipitation reaching vegetation
which has the potential to affect the long-term composition and density of vegetation. The replacement
of vegetation with pollution generating impervious surfaces (PGIS) also has the potential to permanently
impact wetland hydrology.
Because construction details, including means and methods, have not been determined for this analysis,
it is assumed that wherever the Project Alternative footprint intersects a wetland, that area will be
filled. It is unclear what mitigation strategy will take place for the Project Alternatives, but it is assumed
that the impacts will be mitigated according to local, state, and federal regulations regarding wetlands
and wetland buffers.
Aquatic Species and Habitats
The location and final design of the preferred alternative, construction footprint and methods and BMPs
utilized during construction will determine the actual impacts to aquatic species and aquatic habitat. At
this time, construction and design details are unavailable. Following the selection of a Preferred
Alternative, compliance with the ESA would be assessed and documented through a no -effect
memorandum, Biological Assessment, or other ESA documentation. The assessment would also include
a review of potential effects on essential fish habitat, as required by the Magnuson -Stevens Fishery
Conservation and Management Act.
Potential impacts to aquatic species and habitat include in -stream habitat alteration and changes to fish
passage through vegetation removal, the addition of nighttime lighting and daytime shading, and
changes to water quality and quantity.
Temporary construction -related impacts on aquatic species and habitat would occur where in -water
work produces noise, sedimentation, and turbidity and where vegetation is cleared within the stream
buffer. Temporary impacts will also occur where streams are rerouted to accommodate Project
features.
Noise resulting from in -water construction activities has the potential to cause adverse physiological
effects on fish including hearing loss, tissue damage, and behavioral responses. Noise can also
temporarily degrade critical habitat. Primary avoidance and minimization measures include an
underwater sound control and abatement plan and operating during a designated work window that
avoids the timing of aggregated fish use, such as migration. If the appropriate avoidance and mitigation
measures are put in place, impacts to aquatic species and habitat are expected to be temporary.
In -water construction activities have the potential to mobilize disturbed sediments and could increase
turbidity downstream. A Construction Stormwater General Permit will be acquired before construction
begins. A site -specific SWPPP with temporary erosion and sediment controls will be implemented before
construction begins and will be maintained during the duration of the Project. Mitigation and
minimization measures are discussed in detail in Section 4.3.5.
134
Vegetation clearing within the stream buffer will have differing levels of impact depending on the
existing vegetation in the area. Removal of vegetation that is woody in nature, such as a tree or shrub,
would result in a longer -term impact than if an herbaceous plant, such as a grass, was removed due to
the amount of time it would take for each respective plant to achieve the size and stature of pre -
construction conditions. If invasive vegetation is removed and replaced with native vegetation, the
impact on riparian function might improve. Currently only the area of riparian vegetation is known for
each alternative. Once a Preferred Alternative is selected, additional measures will be taken to establish
what the existing vegetation is and how it can be restored or improved upon post -construction.
The main distinction between operational impacts for the respective alternatives is due to the differing
areas of land conversion, especially to impervious surfaces. Following construction, there will be an
increase in the amount of stormwater runoff generated due to additional impervious surfaces. This
additional runoff increases the potential for contamination of receiving waterbodies. Additionally,
increased impervious surfaces alter hydrology by decreasing the percolation of surface water. This effect
results in lower base flows as well as higher peak flows which can result in scour or deposition
downstream. Impacts to surface water runoff are further discussed in Section 4.2 Water Resources.
Assuming BMPs and mitigation measures are put in place, the impacts resulting from the addition of
impervious surfaces should be minimal.
Terrestrial Species and Habitats
The Project alternatives exist in highly developed areas with relatively disturbed habitats compared to
less developed, rural areas. Despite the lack of contiguous, undisturbed habitat, there are still
fragmented patches of natural vegetation that may provide suitable habitat or travel corridors for some
wildlife populations. The location and final design of the preferred alternative, footprint, methods, and
BMPs utilized during construction will determine the actual impacts to terrestrial species and terrestrial
habitat. At this time, construction and design details are unavailable.
The marbled murrelet and Pacific peavine are the only ESA -listed terrestrial species with potential to be
in the Project vicinity. Following the selection of a Preferred Alternative, compliance with the ESA would
be assessed and documented through a no -effect memorandum, Biological Assessment, or other ESA
documentation.
The only priority habitats known or expected to be in the study area are a biological corridor, riparian
areas, and wetlands. Potential direct long-term impacts to terrestrial species and terrestrial habitat
could occur where project construction converts vegetation or other wildlife features to roads or
bridges.
Existing vegetation in the Project footprint would be removed and replaced with PGIS. General impacts
associated with vegetation removal or clearing activities include: removal of trees or other vegetation
which provide suitable habitat, introduction of noxious weeds or exotic species, ground or soil
disturbance or compaction, increased bank or soil erosion, sedimentation, noise impacts, human
presence or activity impacts, or impacts on prey species. Elevated structures may limit the amount of
sunlight and precipitation reaching vegetation which has the potential to affect the long-term
composition and density of vegetation.
135
No plant surveys have been conducted in the Project vicinity. The only protected plant species with
potential to be in the action area is Pacific pea vine. If vegetation is cleared during the construction
phase of the project and Pacific pea vine is located on the site, there would be potential impact to the
plant. Alternatives with the most land conversion from vegetated to non -vegetated have the greatest
potential to impact Pacific pea vine.
The severity of impact for each study area is largely determined by the affected landcover type. In much
of the study areas, replacement of existing PGIS would have minor impact on ecological functions. The
greatest impacts would occur where native vegetation or structurally complex vegetative communities
are replaced by PGIS.
Clearing of trees, snags, and understory vegetation could impact sensitive species located in the Project
vicinity. Vegetation clearing could destroy suitable foraging or nesting habitat for bird species. Under the
Migratory Bird Treaty Act (MBTA), it is illegal to remove an active nest, but nest activity is defined as
being actively used (e.g. eggs or young in the nests). If construction activities occur outside of the
nesting period, this impact will be mitigated. Vegetation clearing can also eliminate potential roosting
sites for bats as well as cover for small mammals. Mitigation and minimization measures are further
discussed in Section 4.3.5.
4.3.4.1 No Action Alternative
A detailed description of the No Action Alternative components and routes are provided in Section 3.3.
Figure 4.3-1 shows the wetland study area, Figure 4.3-7 shows the aquatic study area, and Figure 4.3-12
shows the landcover and terrestrial study area for the No Action Alternative.
4.3.4.1.1 Construction Ilmpacts for the No Action Alternative
Not applicable Construction is not required for the No Action Alternative; therefore, construction
impacts are not applicable for this alternative.
4.3.4.1.2 Operations Ilmpacts for the No Action Alternative
4.3.4.1.2.1 Wetlands
No Impact Under the No Action Alternative, existing conditions for wetlands would continue. No
wetlands are identified in the wetland study area because the No Action Alternative is already
constructed and will not have additional impacts on the existing wetlands. The landcover types within
the No Action Alternative are detailed in Table 4.3-13.
136
Table 4.3-1.3 I.andcov
Landcover Class
Bare Soil
Grass/Low-Lying Vegetation
Impervious Surfaces
Open Water
Tree Canopy
Unclassified (Unincorporated King County)
or th
No Action Alternative
Total
Area within NAA Footprint
2.23
11.84
2.98
0.15
10.75
0.23
28.18
Area within 200' buffer
3.19
9.79
20.21
0.00
8.13
1.55
42.88
Total Area
5.42
21.64
23.20
0.15
18.88
1.78
71.06
Aquatic Species and Habitat
No Impact Under the No Action Alternative, existing conditions for aquatic species and habitat would
continue. The No Action Alternative crosses the Duwamish River, but would not create additional
impacts based on current operating conditions.
4.3.4.1.2.2 Terrestrial Species and Habitat
No to Minor Impact Potential operational impacts to terrestrial species and terrestrial habitat could
occur where operational -related noise, light, and human activity exceeds existing conditions.
The Project vicinity is bordered by Seattle City Light transmission corridor to the north, 1-5 and BNSF's
South Seattle Intermodal Facility to the east, and the Duwamish River to the south and west. Generally
speaking, this alternative is within an area with high levels of development and human disturbance.
Wildlife that uses habitat in or near the project alternatives are regularly exposed to human activity,
noise, and light.
Noise from human activity has the potential to disrupt wildlife behavior (e.g. foraging activities and
calling). It is not expected that operational noise resulting from the No Action Alternative will noticeably
exceed current sound levels in the Project vicinity. Artificial lighting at night has the potential to affect
foraging, circadian rhythms, and dispersal movements. Effects from artificial lighting should be
minimized by compliance with applicable local lighting standards and BMPs. The land conversion of
suitable habitat is limited in area. As such, it is not expected that the continued operation of this
alternative will have an effect on regional populations of wildlife.
4.3.4.2 Alternative 2: Airport Way South
A detailed description of this proposed Alternative's components and routes are provided in Section
3.4.1. Figure 4.3-2 shows the wetland study area, Figure 4.3-8 shows the aquatic study area, and Figure
4.3-13 shows the landcover and terrestrial study area for Alternative 2.
4.3.4.2.1 Construction Impacts
4.3.4.2.1.1 Wetlands
Temporary impacts on wetlands and wetland buffers resulting from construction of Alternative 2 may
result from staging areas, temporary work areas, access roads, clearing, stockpiles, or erosion and
137
sediment controls. Dewatering may temporarily impact groundwater discharge to wetlands. Other
temporary impacts to wetlands and wetland buffers include soil compaction, accidental spills of
hazardous substances, noise and other disturbances, sedimentation, and the introduction of invasive
species.
The type of wetland and vegetation present may affect the length of impact. Wetlands with emergent
vegetation are likely to recover faster than wetlands with woody vegetation due to the time it takes for
the respective vegetation to achieve pre -construction size and stature.
Minor to Moderate Impact for Alternative 2 is expected depending on construction means and
methods.
4.3.4.2.1.2 Aquatic Species and Habitat
No Impact There are no anticipated construction impacts to aquatic species and habitat under
Alternative 2 because the construction of the proposed project would not occur in or near aquatic
habitat. Existing conditions for aquatic species and habitat would continue under Alternative 2.
4.3.4.2.1.3 Terrestrial Species and Habitat
Minor Impact The loudest noise generating activities in the terrestrial environment for Alternative 2 is
likely to be vegetation clearing and the creation and/or replacement of concrete and pavement
(concrete grinder= 97 dB). Based on the results of Equation 4.3-1, the action area for terrestrial noise -
related effects extending spherically in all directions from the Project vicinity is estimated to be 5,000
feet (0.95 miles) for Alternative 2.
There are no known nesting birds in the area, and Alternative 2 would be located in an area currently
used as a firearms training facility. Alternative 2 should be surveyed for active nests prior to
construction. This alternative will require extensive vegetation removal; however, the quality and
density of existing vegetation is unknown at this time. If this Alternative is chosen as the Preferred
Alternative, vegetation surveys would need to be conducted to assess the impact on terrestrial species
and habitat. Table 4.3-13 details the area of land converted from vegetation to impervious surfaces.
4.3.4.2.2 Operations lImpacts
4.3.4.2.2.1 Wetlands
4.3.4.2.2.1.1 Wetlands- Direct Impacts
Mitigated Significant Impact Alternative 2 has the greatest extent of impact on wetlands and wetland
buffers based on acres of area affected. Four wetlands with moderate levels of habitat functions totaling
1.42 acres would be permanently impacted by this alternative. The wetland buffers associated with this
impact would total 5.7 acres.
The quality of wetlands affected In Alternative 2 are similar to Alternative 3B and marginally higher
quality than Alternative 4.
138
Table 4..3-14 Direct long
Wetland
Name
4a
4b
erm impacts to wetlands in Alternative 2 study area
HGM
Classification
Depressional
.......................................................................
Depressional
Depressional
Depressional
Depressional
........................................................................
Depressional
Cowardin
Classification
PFO/PSS/PEM
..............................................................................
PFO/PSS/PEM
PFO/PSS/PEM
..............................................................................
PEM
PFO/PSS/PEM
..............................................................................
PSS/PEM
Wetland
Rating
I; habitat
score of 6
.......................................................................
III; habitat
score of 5
II; habitat
score of 6
.......................................................................
II; habitat
score of 4
II; habitat
_.__..
score of 4
.......................................................................
II; habitat
score of 5
Wetland Area
Impacted by
Alternative 2
footprint (acres)
0.32
0.
0.54
0.03
0.42
0.00
Total 1,42
Wetland Buffer
Area Impacted by
Alternative 2
footprint (acres)
1.17
Total Area Impacted
by Alternative 2
footprint (acres)
4.3.4.2.2.1.2 Wetlands- Indirect Impact
Moderate Impact Indirect operational impacts could result from the addition of impervious surfaces.
Existing conditions within the Alternative 2 footprint are currently covered with primarily grass/low-lying
vegetation or tree canopy. Impervious surfaces occupy 2.98 acres, or 10.6%, of the Project footprint.
Alternative 2 would increase the area of impervious surfaces to approximately 28.18 acres which is an
additional 25.2 acres of new impervious surfaces (Table 4.3-15). Alternative 2 would create more new
impervious surfaces than Alternative 3B or 4, resulting in altered surface water hydrology. Stormwater
systems are expected to mitigate the impacts of surface water runoff, as discussed in Section 4.3.5.
The increase in impervious surfaces, removal of vegetation, and increase in truck traffic will elevate
noise levels in the area. Increased noise levels have the potential to disturb wildlife that utilize wetland
habitat. The quality of wetlands affected are similar to Alternative 3B and marginally higher quality than
Alternative 4. Because Alternative 2 has the greatest amount of land conversion, it is also likely to have
the greatest change in baseline noise levels.
Table 4..3-15 Land cover of Alternative 2
Landcover Class
Bare Soil
Grass/Low-Lying Vegetation
Impervious Surfaces
Open Water
Tree Canopy
2.23
11.84
2.98
0.15
10.75
139
Area within Alt 2 200'
buffer
3.19
9.79
20.21
0.00
8.13
Total
Area
5.42
21.64
23.20
0.15
18.88
Landcover Class
Unclassified (Unincorporated King
County)
Total
Area within Alt 2 Footprint
0.23
28.18
Area within Alt 2 200'
buffer
1.55
42.88
Total
Area
1.78
71.06
4.3.4.2.2.2 Aquatic Species and Habitat
4.3.4.2.2.2.1 Aquatic Species and Habitat- Direct Impact
No Impact Alternative 2 does not intersect with a stream or stream buffer. Therefore, in -stream habitat
alteration, changes to fish passage, vegetation removal, nighttime lighting, and shading for Alternative 2
for expected to result in no impact.
4.3.4.2.2.2.2 Aquatic Species and Habitat- Indirect Impacts
Minor Impact The conversion of land to PGIS (discussed under wetlands impacts) will impact aquatic
species and habitat if not properly mitigated by altering water quality and quantity. Increased
stormwater runoff would increase pollutants such as 6PPD-q which would potentially have lethal
impacts on aquatic species in receiving waterbodies. Impacts to water quality and quantity are discussed
in Section 4.2 Water Resources.
4.3.4.2.2.3 Terrestrial Species and Habitat
Minor Impact Potential operational impacts to terrestrial species and terrestrial habitat could occur
where operational -related noise, light, and human activity exceeds existing conditions.
Proposed Alternative 2 is bordered by Seattle City Light transmission corridor to the north, 1-5 and
BNSF's South Seattle Intermodal Facility to the east, and the Duwamish River to the south and west.
Generally speaking, this alternative is within an area with high levels of development and human
disturbance. Wildlife that uses habitat in or near the project alternatives are regularly exposed to human
activity, noise, and light.
Alternative 2 would require extensive ground clearing; however, the quality and density of existing
vegetation is unknown at this time. If this alternative is chosen as the Preferred Alternative, vegetation
surveys would need to be conducted to fully assess the impact on wetlands
Noise from human activity has the potential to disrupt wildlife behavior (e.g. foraging activities and
calling). It is not expected that operational noise resulting from Alternative 2 would noticeably exceed
current sound levels in the Project vicinity. Artificial lighting at night has the potential to affect foraging,
circadian rhythms, and dispersal movements. Effects from artificial lighting should be minimized by
compliance with applicable local lighting standards and BMPs. The land conversion of suitable habitat is
limited in area. As such, it is not expected that operation of Alternative 2 would have an effect on
regional populations of wildlife.
4.3.4.3 Alternative 3B: Improvements to 48th Place South
A detailed description of this proposed Alternative's components and routes are provided in Section
3.4.2. Figure 4.3-3 shows the wetland study area, Figure 4.3-9 shows the aquatic study area, and Figure
4.3-14 shows the Landcover and terrestrial study area for Alternative 3B.
140
4.3.4.3.1 Construction lImpacts
4.3.4.3.1.1 Wetlands
Temporary impacts on wetlands and wetland buffers resulting from construction of Alternative 3B may
result from staging areas, temporary work areas, access roads, stream relocations, cofferdams, clearing,
stockpiles, or erosion and sediment controls. Dewatering may temporarily impact groundwater
discharge to wetlands. Other temporary impacts to wetlands and wetland buffers include soil
compaction, accidental spills of hazardous substances, noise and other disturbances, sedimentation, and
the introduction of invasive species.
The type of wetland and vegetation present may affect the length of impact. Wetlands with emergent
vegetation are likely to recover faster than wetlands with woody vegetation due to the time it takes for
the respective vegetation to achieve pre -construction size and stature.
Minor to Moderate Impact for Alternative 3B is expected depending on construction means and
methods.
4.3.4.3.1.2 Aquatic Species and Habitat
Moderate Impact There would be temporary impacts to aquatic species and habitat in the Duwamish
River during construction for Alternative 3B; however, the extent of impacts will not be made clear until
construction means and methods are decided. Mitigation measures, including fish exclusion, would
minimize the impact.
Potential temporary construction impacts from Alternative 3B include:
• Temporary degradation of habitat from sedimentation, removal of riparian vegetation, and
disturbance to stream banks
• Physical modifications to migration and rearing habitat during in -water work including
temporary loss of physical habitat from dewatering
• Temporary degradation of water quality (increased temperature and turbidity) due to
vegetation removal and in -water construction
Alternative 3B is the only alternative that may include in -water work. The noise generated for this work
could potentially affect aquatic species, including three federally listed fish. The extent of noise
propagation in a river system is determined with a line -of -sight rule meaning the noise may propagate
into any area that is within the line -of -sight of the noise source (WSDOT 2023). The sinuosity of rivers
limits the propagation of noise, and it is unlikely that noise will propagate where a river bends (WSDOT
2023). Based on this methodology, the aquatic action area for Alternative 3B extends approximately
1,110 upriver and 900 downriver. While mitigation measures and BMPs will be followed for noise and
vibration impacts, it is not likely that all impacts will be avoided. Mitigation and minimization measures
are discussed in Section 4.3.5.
4.3.4.3.1.3 Terrestrial Species and Habitat
Minor Impact It is assumed vibratory, or impact, hammers (105dB) would be used for building the
bridge for proposed Alternative 3B, which will likely be the loudest construction equipment used for that
alternative. Based on Equation 4.3-1, the action area for terrestrial noise -related effects extending
spherically in all directions from the Project vicinity is estimated to be 12,559 feet (2.38 miles) for
Alternative 3B.
141
There are no known nesting birds in the area. Alternative 3B should be surveyed for active nests prior to
construction. Table 4.3-17 details the area of land converted from vegetation to impervious surfaces.
This alternative would require a bridge crossing the Duwamish River with five feet of minimum
freeboard above the river. In order to achieve the required clearances above the river, Railroad Avenue
would need to be raised to align with the new grade changes. This elevation adjustment would require
the construction of retaining walls along the eastern edge of Railroad Avenue to support the new grade
change. Elevated structures have the potential to impact vegetation; however, the quality and density of
existing vegetation is unknown at this time. If this Alternative is chosen as the Preferred Alternative,
vegetation surveys would need to be conducted to assess the impact on terrestrial habitat.
4.3.4.3.2 Operations Ilmpacts
4.3.4.3.2.1 Wetlands
4.3.4.3.2.1.1 Wetlands- Direct Impact
Mitigated Significant Impact Alternative 3B would have the least amount of impact on wetlands and
wetland buffers after the No Action Alternative based on acres of area affected. Three wetlands with
moderate levels of habitat functions totaling 0.14 acres would be permanently impacted by this
alternative. The wetland buffers associated with this impact would total 0.65 acres (Table 4.3-16). The
quality of wetlands affected are similar to Alternative 2 and marginally higher quality than Alternative 4.
Alternative 3B would require a bridge crossing the Duwamish River with five feet of minimum freeboard
above the river. Elevated structures have the potential to impact vegetation by casting shade; however,
the quality and density of existing vegetation is unknown. If this alternative is chosen as the Preferred
Alternative, vegetation surveys would need to be conducted to assess the impact on wetlands.
Table 4..3-16 Direct long• -term impacts to wetlands in the Alternative .3B study area
Wetland
Name
HGM Cowardin
Classification Classification
Tidal Fringe
Tidal Fringe
Depressional
Depressional
PSS/PEM
.....................................................................
PFO/PSS/EEM
PFO/PSS
.....................................................................
PSS/PEM
Note: Numbers may not sum due to rounding
Wetland Rating
II (based on
estuarine special
characteristic);
habitat score of 6
.........................................................................................
I (Based on
estuarine special
characteristic);
habitat score of 6
II; habitat score
of 5
II (Based on
estuarine special
characteristic);
habitat score of 6
Total
Wetland Area
Impacted by Alt 3B
footprint (acres)
0.00
0.00
0.10
0.01
0.11
Wetland Buffer
Area Impacted by
Alt 3B footprint
(acres)
0.19
0.00
0.27
0.19
0.65
Total Area
Impacted by Alt 3B
footprint (acres)
0.20
0.00
0.37
0.19
0.76
4.3.4.3.2.1.2 Wetlands- Indirect Impact
Moderate Impact Indirect operational impacts could result from the addition of impervious surfaces.
Existing conditions within the Alternative 3B footprint have very little vegetation. Impervious surfaces
142
occupy 2.19 acres, or 73.49%, of the Project footprint. Alternative 3B would increase the coverage of
impervious surfaces to approximately 2.87 acres which is an additional 0.68 acres of new impervious
surfaces (Table 4.3-17). Alternative 3B will create the least amount of new, impervious surfaces
compared to the other build alternatives (Alternatives 2 and 4), resulting in altered surface water
hydrology. Stormwater systems are expected to mitigate the impacts of surface water runoff. Mitigation
measures are further discussed in Section 4.3.5.
The increase in impervious surfaces, removal of vegetation, and increase in truck traffic will elevate
noise levels in the area. Increased noise levels have the potential to disturb wildlife that utilize wetland
habitat. The quality of wetlands affected are similar to Alternative 2 and are marginally higher in quality
than Alternative 4. Alternative 3B involves building a bridge that will cross the Duwamish River,
elevating noise levels in the area to an unknown extent.
Table 4..3•-..1.7 Land cover of Alternative .3B
Landcover Class
Bare Soil
Grass/Low-Lying Vegetation
Impervious Surfaces
Open Water
Tree Canopy
Unclassified (Unincorporated King County)
Total
Area within Alt 3B Footprint
0.02
0.14
2.19
0.11
0.41
0.00
2.87
4.3.4.3.2.2 Aquatic Species and Habitat
4.3.4.3.2.2.1 Aquatic Species and Habitat- Direct Impacts
Avoidable Significant Impact
Area within Alt 3B 200'
buffer
0.10
2.96
18.64
3.59
4.73
0.00
30.03
Total Area
0.12
3.10
20.83
3.71
5.14
0.00
32.89
In -stream habitat alteration: This alternative has the potential to impact the Duwamish River.
Alternative 3B would construct a bridge that would cross the Duwamish River and would likely include
in -water work. The bridge that would cross the Duwamish River has not yet been designed, so exact
impacts are unknown. However, in 2022 Trantech Engineering LLC designed a bridge for a previous
alternative that has since been dismissed (Trantech 2022). This design was used to inform assumptions
about the bridge that would be constructed for Alternative 3B including:
1. The preferred bridge alignment is a three -span steel plate girder with five to six feet of
freeboard, which is above the 100-year flood zone.
2. In -water construction will include a temporary falsework bent for steel erection and work
platforms near the shoreline that extend into the river below High Tide Line (HTL). The bent will
require pile driving.
3. The piers supporting the bridge will be below HTL.
143
Due to in -water work below the HTL, fourteen Priority Species including three federally threatened fish
species, and federally designated Critical Habitat would be impacted by this alternative. Any work below
the HTL in the study area would be conducted in accordance with the terms of the Hydraulic Project
Approval (HPA) and other applicable permits obtained for this project. Any in -water work would be
required to occur during preferred "work windows," which are periods of the year when fish would be
minimally impacted.
Fish passage: The Duwamish River is classified as "migration only" habitat for bull trout and steelhead,
and as "migration and rearing" habitat for fall -run chinook (PSMFC 2024). Spawning habitat has not
been identified in or near the Alternative 3B study area. This section of the Duwamish River is heavily
modified, and the water is tidally influenced and brackish, making it unsuitable for spawning fish.
Therefore, Alternative 3B will not affect spawning. Physical modifications to migration and rearing
habitat will occur permanently where the piers supporting the bridge reach below HTL. Mitigation
measures, including fish exclusion, would minimize the impact; mitigation measures are discussed in
greater detail in Section 4.3.5.
Vegetation removal and habitat alteration: The ecological functions of a stream's riparian buffer are
diminished where the project footprint intersects with the buffer. Elevated structures with a clearance
of less than 15 feet could preclude vegetation regrowth due to shading effects. Replacing riparian
vegetation with impervious surfaces (road or bridge) or vegetation lacking similar structural or
compositional diversity increases the level of impact. Riparian vegetation provides numerous ecosystem
functions including fish and wildlife habitat; food chain support; water temperature maintenance;
infiltration; groundwater recharge and discharge; sediment delivery, transport, and storage; organic
matter input; nutrient and pathogen removal; and stream channel formation and maintenance. The
majority of riparian functions, including water quality protection, channel maintenance, detrital input
(Fischer and Fischenich 2000) and large woody debris recruitment (Murphy and Koski 1989; McDade
et.al. 1990; McKinley 1997; Martin et al. 1998), occurs within the first 100 feet of a stream's buffer.
Vegetation clearing near the Duwamish River would increase the risk of erosion and decrease the
available shade in the river. Decreased shading can contribute to increased water temperatures which
could have a negative impact on fish species, including three federally protected species. Approximately
0.10 acres of riparian vegetation would be removed for proposed Alternative 3B; however, it is unclear
what the composition of is the vegetation communities are.
Nighttime Lighting: Bridge luminaries would be within 50 feet of the Duwamish River which will increase
nighttime illumination of the river. Nighttime illumination of surface waters has the potential to increase
predation on juvenile salmonids. This impact can be avoided or mitigated by selecting a luminary that is
shielded and directs light away from the water's surface. Alternative 3B would construct a bridge that
crosses the Duwamish River that is approximately 150 feet in length. The bridge would be illuminated;
however, it is unknown what type of illumination would be included.
Shading: Elevated segments of roadway or bridges over or near surface flowing streams have the
potential to increase shade in surface flowing waters affecting the behavior of fish. One study found out -
migrating juvenile salmonids paused upstream of shaded surface water, moved upstream to avoid
shaded water, and moved more slowly through dark water than light water, resulting in an increased
predation risk (Kemp and Williams 2008). Additionally, artificial shade can reduce foraging success of
salmonids by decreasing underwater visibility (Munsch et al. 2015) and by inhibiting the success of
144
invertebrate prey species (Cordell et.al. 2017). Affected in -stream habitat includes the length of the
surface -flowing stream within the study area. Approximately 0.17 acres of stream area would be shaded
by the footprint of the bridge for Alternative 3B.
4.3.4.3.2.2.2 Aquatic Species and Habitat- Indirect Impacts
Moderate Impact The conversion of land to PGIS, discussed under wetlands impacts, would impact
aquatic species and habitat by altering water quality and quantity if not properly mitigated. Increased
stormwater runoff would alter hydrology and increase pollutants such as 6PPD-q which would
potentially have lethal impacts on aquatic species in receiving waterbodies.
4.3.4.3.2.3 Terrestrial Species and Habitat
Minor Impact Potential operational impacts to terrestrial species and terrestrial habitat could occur
where operational -related noise, light, and human activity exceeds existing conditions.
Alternative 3B is bordered by Seattle City Light transmission corridor to the north, 1-5 and BNSF's South
Seattle Intermodal Facility to the east, and the Duwamish River to the south and west. Generally
speaking, this alternative is within an area with high levels of development and human disturbance.
Wildlife that uses habitat in or near the proposed alternative are regularly exposed to human activity,
noise, and light.
Noise from human activity has the potential to disrupt wildlife behavior (e.g. foraging activities and
calling). It is not expected that operational noise resulting from the Project will noticeably exceed
current sound levels in the Project vicinity. Artificial lighting at night has the potential to affect foraging,
circadian rhythms, and dispersal movements. Effects from artificial lighting should be minimized by
compliance with applicable local lighting standards and BMPs. The land conversion of suitable habitat is
limited in area. As such, it is not expected that operation of Alternative 3B would have an effect on
regional populations of wildlife.
4.3.4.4 Alternative 4: New Bridge from SR-900 to South 129th Street
A detailed description of this proposed Alternative's components and routes are provided in Section
3.4.3. Figure 4.3-4 and Figure 4.3-5 show the wetland study areas, Figure 4.3-10 and Figure 4.3-11 show
the aquatic study areas, and Figure 4.3-15 and Figure 4.3-16 show the landcover and terrestrial study
areas for Alternative 4.
4.3.4.4.1 Construction Ilmpacts
4.3.4.4.1.1 Wetlands
Temporary impacts on wetlands and wetland buffers resulting from construction of Alternative 4 may
result from staging areas, temporary work areas, access roads, stream relocations, cofferdams, clearing,
stockpiles, or erosion and sediment controls. Dewatering may temporarily impact groundwater
discharge to wetlands. Other temporary impacts to wetlands and wetland buffers include soil
compaction, accidental spills of hazardous substances, noise and other disturbances, sedimentation, and
the introduction of invasive species.
The type of wetland and vegetation present may affect the length of impact. Wetlands with emergent
vegetation are likely to recover faster than wetlands with woody vegetation due to the time it takes for
the respective vegetation to achieve pre -construction size and stature.
145
Minor to Moderate Impact for Alternative 4 is expected depending on construction means and
methods.
4.3.4.4.1.2 Aquatic Species and Habitat
Minor to Moderate Impact There would be temporary impacts to aquatic species and habitat in Stream
1 during construction for Alternative 4; however, the extent of impacts will not be made clear until
construction means and methods are decided. Stream 1 is a potentially fish -bearing stream that has an
unknown outlet. It is assumed to discharge to a large wetland complex downslope.
Potential temporary construction impacts from Alternative 4 include:
• Temporary degradation of habitat from sedimentation, removal of riparian vegetation, and
disturbance to stream banks
• Temporary degradation of water quality (increased temperature and turbidity) due to
vegetation removal and near -by construction
• Temporary loss of physical habitat from dewatering or rerouting
There would potentially be noise related impacts in the aquatic environment for Alternative 4. Stream 1
is a non -fish -bearing stream; however, other species that utilize it as aquatic habitat may be affected by
in -water noise. Due to its proximity to the Duwamish River, if an impact or vibratory hammers are used
during construction, aquatic noise impacts will need to be reevaluated.
4.3.4.4.1.3 Terrestrial Species and Habitat
Minor Impact The loudest noise generating activities in the terrestrial environment for Alternative 4
would likely be vegetation clearing and the creation and/or replacement of concrete and pavement
(concrete grinder= 97 dB). Based on the results of Equation 4.3-1, the action area for terrestrial noise -
related effects extending spherically in all directions from the Project vicinity is estimated to be 5,000
feet (0.95 miles) for Alternative 4.
An osprey nest found was found near Alternative 4. This nest would be impacted if construction occurs
within the nesting window. Alternative 4 should be surveyed for active nests prior to construction, if this
is selected as the Preferred Alternative. The East Duwamish Greenbelt -Seattle area, a biodiversity area
and corridor identified as PHS, intersects the northern section of Alternative 4. Terrestrial species that
utilize the biodiversity area and corridor may avoid the area during construction or may be displaced by
the conversion of habitat.
This alternative would require a noise wall that would be installed between the new truck access road
and 51st Place South, and a tall retaining wall would be constructed to support the hillside. Elevated
structures have the potential to impact vegetation; however, the quality and density of existing
vegetation is unknown at this time. Table 4.3-19 details the area of land that would be converted from
vegetation to impervious surfaces for Alternative 4. Vegetation clearing near the Duwamish River would
increase the risk of erosion and would decrease the available shade in the river. If this Alternative is
chosen as the Preferred Alternative, vegetation surveys would need to be conducted to assess the
impact on terrestrial habitat.
146
4.3.4.4.2 Operations Ilmpacts
4.3.4.4.2.1 Wetlands
4.3.4.4.2.1.1 Wetlands- Direct Impact
Mitigated Significant Impact Alternative 4 would have slightly more impact than Alternative 3B on
wetlands and wetland buffers based on acres of area affected. Three wetlands with low to moderate
levels of habitat functions, totaling 0.18 acres, would be permanently impacted by this alternative. The
wetland buffers associated with this impact would total 0.74 acres (Table 4.3-18). The quality of
wetlands affected are marginally lower quality than the other build alternatives (Alternatives 2 and 3B).
Alternative 4 would require a noise wall that would be installed between the new truck access road and
51st Place South and would need a tall retaining wall to be constructed to support the hillside. Elevated
structures have the potential to impact vegetation; however, the quality and density of existing
vegetation is unknown at this time. If this Alternative is chosen as the Preferred Alternative, vegetation
surveys would need to be conducted to assess the impact on wetlands.
Table 4..3-18 Direct long• -term impacts to wetlands in Alternative 4 study area
Wetland
Name
HGM Cowardin Wetland Rating
Classification Classification
Tidal Fringe
PSS/PEM
Tidal Fringe PFO/PSS/EEM
Depressional PFO/PSS
Depressional
10 Depressiona
11 Slope
II (based on
estuarine special
characteristic);
habitat score of
6
.......................................................
I (Based on
estuarine special
characteristic);
habitat score of
6
11; habitat score
of 5
Wetland Area
Impacted by Alt 4
footprint (acres)
0.00
0.00
0.03
PSS/PEM II (Based on 0.00
estuarine special
characteristic);
habitat score of
PEM
PSS
12a Riverine/ PFO/PSS
Slope
12b Riverine/ PFO
Slope
I; habitat score
of 6
.................................................................................
III; habitat score
of 6
II; habitat score
of 6
II; Habitat Score
of 6
Total
147
0.00
0.03
Wetland Buffer
Area Impacted by
Alt 4 footprint
(acres)
0.00
ww,w�,w,w,w,w,w,
0.00
0.46
0.00
0.26
0.27
Total Area
Impacted by Alt 4
footprint (acres)
0.00
0.00
0.49
0.00
0.26
0.30
4.3.4.4.2.1.2 Wetlands- Indirect Impact
Minor Impact Indirect operational impacts could result from the addition of impervious surfaces.
Existing conditions within the Alternative 4 footprint are a mix of unclassified land cover, tree canopy,
and impervious surfaces. Impervious surfaces occupy 1.73 acres, or 26.25%, of the proposed Alternative
footprint. Alternative 4 would increase the coverage of impervious surfaces to approximately 6.59 acres,
which is an additional 4.86 acres of new impervious surfaces (Table 4.3-19). Alternative 4 would create
more new, impervious surfaces than Alternative 3B, but less than Alternative 2, resulting in altered
surface water hydrology. Stormwater systems are expected to mitigate the impacts of surface water
runoff.
The increase in impervious surfaces, removal of vegetation, and increase in truck traffic would elevate
noise levels in the area. Increased noise levels have the potential to disturb wildlife that utilize wetland
habitat. The quality of wetlands that would be affected in Alternative 4 are marginally lower quality than
for Alternatives 2 and 3B. This alternative would require a noise wall that would be installed between
the new truck access road and 51st Place South, and would require a tall retaining wall to be
constructed to support the hillside, resulting in lower noise impacts than Alternatives 2 and 3B.
Table 4..3-19 Land cover of Alternative 4
Landcover Class
Bare Soil
Grass/Low-Lying Vegetation
Impervious Surfaces
Open Water
Tree Canopy
Unclassified (Unincorporated King County)
Total
Area within Alt 4 Footprint
0.03
0.53
1.73
0.00
1.84
2.46
6.59
Area within Alt 4 200'
buffer
1.00
7.63
18.37
1.79
11.89
9.58
50.25
Total Area
1.03
8.15
20.10
1.79
13.72
12.05
56.84
4.3.4.4.2.2 Aquatic Species and Habitat
4.3.4.4.2.2.1 Aquatic Species and Habitat- Direct Impacts
Avoidable Significant Impact Alternative 4 would intersect Stream 1 which has the potential for
anadromous fish. Therefore, in -stream habitat alteration and fish passage are not expected to be
impacted for this alternative.
Vegetation removal: Approximately 0.003 acres of riparian vegetation around Stream 1 would be
removed for Alternative 4; however, it is unclear what the composition of this vegetation is.
Nighttime lighting: Alternative 4 would be within 50 feet of the Duwamish River for a segment of
approximately 180 feet, which is in close enough proximity to illuminate the river at night.
Shading: Approximately 0.004 acres of stream area would be potentially shaded by the footprint of
Alternative 4, depending on how it is constructed. Potential construction activities that would require
148
further analysis include, but are not limited to, stream relocation, dewatering, or enclosing the stream in
a pipe.
Water Quality and Quantity: The conversion of land to PGIS, discussed under the wetlands impacts
would impact aquatic species and habitat. If not properly mitigated, the increase in PGIS could have a
significant impact on aquatic species and habitat.
4.3.4.4.2.2.2 Aquatic Species and Habitat- Indirect Impacts
Moderate Impact The conversion of land to PGIS, discussed under wetlands impacts, would impact
aquatic species and habitat by altering water quality and quantity if not properly mitigated. Increased
stormwater runoff would alter hydrology and increase pollutants such as 6PPD-q which would
potentially have lethal impacts on aquatic species in receiving waterbodies.
4.3.4.4.2.3 Terrestrial Species and Habitat
Minor Impact Potential operational impacts to terrestrial species and terrestrial habitat could occur
where operational -related noise, light, and human activity exceeds existing conditions.
The Alternative 4 vicinity is bordered by Seattle City Light transmission corridor to the north, 1-5 and
BNSF's South Seattle Intermodal Facility to the east, and the Duwamish River to the south and west.
Generally speaking, this alternative is within an area with high levels of development and human
disturbance. Wildlife that uses habitat in or near proposed Alternative 4 are regularly exposed to human
activity, noise, and light.
Noise from human activity has the potential to disrupt wildlife behavior (e.g. foraging activities and
calling). It is not expected that operational noise resulting from Alternative 4 would noticeably exceed
current sound levels in the Project vicinity. Artificial lighting at night has the potential to affect foraging,
circadian rhythms, and dispersal movements. Effects from artificial lighting should be minimized by
compliance with applicable local lighting standards and BMPs. The land conversion of suitable habitat is
limited in area. As such, it is not expected that operation of Alternative 4 would have an effect on
regional populations of wildlife.
4.3.5 Mitigation Measures
The mitigation measures identified in this section are common measures for the construction activities
identified within the scope of the project. Once an alternative is selected as the preferred alternative,
specific mitigation measures and best management practices will be determined.
4.3.5.1 Stormwater
The City's stormwater permitting process involves review of all stormwater site plans for proposed
development activities. Tukwila administers and reviews site engineering plans and permits to address
clearing, grading, paving, stormwater management system, roadway, and right-of-way activities. Tukwila
adopted the 2021 King County surface water Design Manual (KCSWDM) which achieves equivalency
with Ecology's Stormwater Management Manual for Western Washington. Per the Tukwila Stormwater
Management Plan, the following local regulations, rules, and standards must be followed:
• TMC 14.30: Tukwila Surface and Stormwater Management Code, including adoption of the most
current KCSWDM.
• TMC 8.45: Code Enforcement
• TMC 18.45: Zoning Environmentally Sensitive Areas
149
• Tukwila Infrastructure Design and Construction Standards
4.3.5.2 Aquatic area buffers
• Contractor staging areas should not be within 200 feet of potentially suitable wetland, stream,
estuarine, river or marine drainage, unless site specific review completed indicates that no
impacts to the sensitive resource areas will occur due to topography or other factors.
• Temporary material storage piles consisting of erosive materials should be placed outside the
100-year floodplain during the rainy season (October 1 through June 1). Such temporary storage
piles should be stabilized with plastic sheeting, straw bales, or other BMPs, to prevent sediment
delivery to these waterbodies.
• All excavated materials should be removed to an upland location where they cannot enter the
water body.
4.3.5.3 Vegetation removal
• Where riparian vegetation has been removed from aquatic resources, disturbed areas will be
isolated using erosion control features (such as silt fencing or hay bales) until disturbed areas
are stabilized or revegetated
• Disturbed areas should be replanted with native vegetation or hydroseeded to prevent soil
erosion
• Vegetation should be cut at the ground surface rather than grubbed, which removes the roots.
Vegetation should only be grubbed from areas undergoing permanent alteration. No grubbing
should occur in areas slated for temporary impacts.
• Removal of riparian vegetation should be minimized and replanted where feasible. Replanting
may not be possible in permanent impact areas, the roadway clear zone, or adjacent to or under
bridges. However, potential replanting of riparian vegetation near the site should be evaluated.
• Disturbance to riparian vegetation from the operation of heavy equipment should be minimized
as practicable by straddling it with heavy equipment or by pruning it without damaging the
roots. Existing riparian vegetation outside of the work area should not be removed or disturbed.
4.3.5.4 In -water work
• All work below the HTL level should be conducted during the approved work windows for fish
species that may occur in the Project vicinity (Error! Reference source not found.).
• Streamflow should be diverted during in -water work to minimize turbidity.
• Work should be performed during low flow or dry conditions, or during dry weather.
• The area of in -water work should be isolated from the water body to minimize sediment
impacts (using cofferdams, silt fencing, hay bales, or water sausages), and sediment -laden
waters should be pumped to an infiltration or treatment site.
• The work area should be isolated to avoid impacts on listed fish species, and fish should be
removed from the area if necessary (using seining, netting, and as a last resort, electrofishing).
• Debris or sediments should be disposed of outside the floodplain.
• The activity site should be cleaned after construction to prevent an influx of sediments to
streams after the first large storm event.
• Impacts should be minimized on stream banks and riparian vegetation
• Seasonal restrictions should be applied to work conducted within or below the HTL, should
follow requirements within the HPA issued by the Washington Department of Fish and Wildlife,
150
and Water Quality Standards for Surface Waters of the State of Washington (Chapter 173-201A
WAC). In -water work duration should be minimized as practicable.
• Construction equipment should not enter any water body without authorization from the
USACE, USFWS, NMFS, Ecology, and Washington Department of Fish and Wildlife. Equipment
should be operated as far from the water's edge as possible.
• Listed fish species, including their forage fish, should be removed from the work area prior to
any in -water work activities, unless removal would affect the individuals more than leaving them
on -site. Fish exclusion activities should follow the most recent WSDOT protocol that has been
approved by the NMFS and USFWS.
• Water pumped out of the isolated Project vicinity should be discharged to a temporary storage
and treatment site or to upland areas and filtered through vegetation prior to reentering the
stream channel.
• All intake pumps within fish bearing streams should have a fish screen installed, operated and
maintained. Screening techniques must utilize the specifications in the HPA and be in
compliance with RCW 77.55.010, RCW 77.57.040 and RCW 77.57.070 or the specifications in the
NMFS Anadromous Salmonid Passage Facility Design manual (2011) and NMFS Fish Screening
Criteria for Anadromous Salmonids (1997), whichever is more restrictive.
• Temporary diversion structures should be non -erosive (e.g., sandbags filled with clean gravel
and covered with plastic sheeting, portable bladder dam).
• Temporary bypass systems should utilize non -erosive techniques, such as pipe or a plastic lined
channel that will accommodate the predicted peak flow rate during construction.
• Temporary bypass structures should have energy dissipaters at the outflow to prevent erosion.
• WSDOT Fish Exclusion Protocols and Standards should be followed to conduct work area
isolation, fish capture and removal, and dewatering/rewatering. Flows shall be gradually
reintroduced to the isolated work area, to prevent channel bed or bank instability, excessive
scour, or turbidity and sedimentation.
• Upon completion of all in -water work, all stream diversion devices, equipment, pipe, and
conduits should be removed and disturbed soil should be restored after diversions are removed.
Streambank plantings may occur at a later date during the planting season.
• Projects will not inhibit passage of any listed fish species life stage following completion. When
feasible, a bypass system will be installed during construction to permit both upstream and
downstream passage of listed fish and their prey.
4.3.5.5 Revegetation and slope stability
• Erodible earth not being worked, whether at final grade or not, should be covered. From
October 1 through April 30 erodible earth may be exposed without cover for a 2-day maximum
and from May 1 to September 30 for a 7-day maximum.
• Temporarily disturbed areas should be restored to pre -work conditions to the extent possible,
including protecting existing root systems and allowing re -sprouting of herbaceous and woody
plants. Native trees and shrubs should be used that are endemic to the project vicinity or region
of the State where the activity is occurring.
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4.3.5.6 Pollutant protection
• The contractor should use BMPs, as stated in their Spill Prevention Control and
Countermeasures Plan, to ensure that no foreign material such as oil or fuel from construction
equipment will enter any wetlands, flowing or standing water.
• All equipment should be fueled and maintained more than 200 feet from the nearest wetland,
ditches, flowing or standing water.
• Equipment should be checked daily for leaks and should be well maintained to prevent
lubricants and any other deleterious materials from entering waters of the State. Prior to
entering the water or below the HTL, all equipment should be free of any external petroleum
products, hydraulic fluid, coolants, and other deleterious materials. Wash water should not be
discharged to any water body without pre-treatment.
• All equipment entering waters that may be used by listed fish species and/or if the waters are
critical habitat, should use vegetable oil or other biodegradable acceptable hydraulic fluid
substitute.
4.3.5.7 Concrete work
• Concrete truck chute cleanout areas should be established to properly contain wet concrete and
wash water and prevent it from entering wetlands and other waterbodies.
• The contractor will protect all inlets and catchments from stormwater runoff from fresh
concrete, tackifier, paving, or paint striping if inclement weather unexpectedly occurs.
• All concrete should be poured in the dry, or within confined waters not being dewatered to
surface waters, and should be allowed to cure a minimum of 7 days before contact with surface
water
4.3.5.8 Bridge work
• Bridge construction will take place from the adjacent streambanks, existing bridges, barges, or
temporary work bridges. Some work may be allowed within a dewatered channel or on a dry
gravel bar with WDFW, NMFS and USFWS approval, but no equipment or vehicle staging should
be allowed in these areas.
• New stream crossing structures, including channel -spanning bridges, should not reduce the
existing stream width.
4.3.5.9 Bank protection
• If site -specific conditions allow, fish habitat should be improved by incorporating large woody
debris into bank protection projects.
• Installation of riprap and other materials should occur from the banks or outside the wetted
perimeter as much as possible.
• Project vicinities with existing riprap should be allowed to increase the lineal distance of the
riprapped area below the HTL by an additional 5 percent.
• All materials, such as riprap or gravel, placed within the water should be free of rock fines, silt,
soil, or other extraneous material.
4.3.5.10 Cutting and filling
• Fill material should only be placed in specified and permitted locations. Fill placement may be
permanent or temporary and should be located in a way that minimizes impacts to sensitive
areas.
152
• Temporary fills should be entirely removed and the site restored to pre-existing contours.
4.3.5.11 Pile installation and removal
• Installation of steel piles with an impact hammer in -water requires the use of a bubble curtain
or other approved sound attenuation method(s) to minimize impacts within waterbodies that
may be used by listed species, including marine mammals
• In tidally influenced areas, piles should be driven during slack tides whenever practicable.
• Sound pressure should be monitored per the approved WSDOT Hydroacoustic Monitoring
Protocol for in -water pile driving to determine ambient conditions and the sound pressure
generated during in -water impact pile driving of steel piles, including H-piles, and sheet piles.
Sound pressure monitoring will occur for in -water work where listed fish species may be
present.
4.3.6 Significant Unavoidable Adverse Impacts
Permanent loss of habitat would occur, similar to any major development project on a partially
undeveloped site. However, with the implementation of the required/proposed mitigation measures
listed above, no significant unavoidable adverse impacts to plants and animals would be anticipated.
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4. II...and Use, Shoirellir a Use, and Recreation
4.4.1 Affected Environment
For this section of the EIS, the affected environment for the Land Use, Shoreline Use, and Recreation
resources is defined as the footprint, the truck traffic routes (excluding highways), and a 200-foot buffer
for each of the proposed Alternatives to evaluate impacts to adjacent properties. Land Use and
Recreation resources are typically analyzed by evaluating the parcels of land they occupy and their
adjacent properties; Shoreline Use is typically analyzed using a 200-foot buffer as outlined in the
Washington State Shoreline Management Act. For analysis of this section, a 200-foot buffer was applied
to Land Use, Shoreline Use, and Reaction evenly to evaluate adjacent properties in a standard fashion.
The affected environment for each of the four proposed Alternatives are shown in detailed figures
under each Alternative.
4.4.1.1 Land Use
The Tukwila Comprehensive Plan (TCP) (City 2024e) identifies the values of the City by stating that:
We seek to protect our shoreline, streams, and other natural amenities such as trees and historical
landmarks. We seek to create a natural environment, a physical infrastructure, and community image
that prompts people to respect and care for each other and which attracts newcomers to live, do
business, shop in, visit, and enjoy the special features of the City.
Land Use Districts within the study area Alternatives and truck routes have been defined by the City of
Tukwila Municipal Code (TMC) (18.08.010) (City 2024b), City of Burien Municipal Code (Title 19) (Burien
2019), and King County Code (KCC) (21A) (King County 2024b) and have been delineated through county
and city official zoning maps. There are 15 Land Use Districts within a 200- foot buffer of the proposed
Alternatives and truck routes; they are listed and described in Table 4.1-1 .
Table 4.4-1. Land Use Districts and Descriptions within the proposed Alternatives
Land Use Zone
Description
City of Tukwila
Low Density Residential
(LDR)
This district is intended to provide low -density family residential areas
together with a full range of urban infrastructure services in order to
maintain stable residential neighborhoods, and to prevent intrusions by
incompatible land uses.
High Density Residential
(HDR)
This district is intended to provide a high -density, multiple -family district
which is also compatible with commercial office areas.
Manufacturing Industrial
Center/ Heavy (MIC/H)
This district is intended to provide a major employment area containing
heavy or bulk manufacturing and industrial uses, distributive and light
manufacturing and industrial uses, and other uses that support those
industries.
Manufacturing Industrial
Center/ Light (MIC/L)
This district is intended to provide a major employment area containing
distributive light manufacturing and industrial uses and other uses that
support those industries.
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i and Use Zone
Description
Heavy Industrial (HI)
This district is intended to provide areas characterized by heavy or bulk
manufacturing uses and distributive and light manufacturing uses, with
supportive commercial and office uses. The development standards are the
minimum necessary to assure safe, functional, efficient, and
environmentally sound development.
Light Industrial (LI)
This district is intended to provide areas characterized by distributive and
light manufacturing uses, with supportive commercial and office uses.
Commercial Light Industrial
(CLI)
This district is intended to provide for areas characterized by a mix of
commercial, office, or light industrial uses. The standards are intended to
promote viable and attractive commercial and industrial areas.
Regional Commercial Mixed
Use (RCM)
This district is intended to provide for areas characterized by commercial
services, offices, lodging, entertainment, and retail activities with
associated warehousing, and accessory light industrial uses, along
a transportation corridor and intended for high -intensity regional
uses. Residential uses mixed with certain commercial uses are
allowed at second story or above. The zone's standards are
intended to promote attractive development, an open and pleasant
street appearance, and compatibility with adjacent residential
areas.
Residential Commercial
Center (RCC)
This district is intended to create and maintain pedestrian -friendly
commercial areas characterized and scaled to serve a local neighborhood,
with a diverse mix of residential, retail, service, office, recreational and
community facility uses.
City of Seattle
Industrial and Maritime
MML U/65
MML U/65 is an industrial and maritime zone, which generally allows only
industrial and certain commercial uses with some zones in this class
providing limited opportunities for workforce housing that supports
industrial uses.
Industrial and Maritime
MML U/85
MML U/85 is an industrial and maritime zone, which generally allows only
industrial and certain commercial uses with some zones in this class
providing limited opportunities for workforce housing that supports
industrial uses.
City of Burien
RS-7,200
Single family residential zone. The purpose of these zones is to establish
areas in which a wide range of single-family housing opportunities can be
provided, while preserving the character of the surrounding neighborhood
and protecting environmentally sensitive areas. The intent is to provide a
variety of attractive, well -designed housing choices that meet the needs of
existing and future City residents.
RM-18
Multi -family residential zone. The purpose of these zones is to establish
areas in which a wide range of single-family and multi -family housing
opportunities can be provided, which are compatible with adjacent lower
density single-family housing, and which protect environmentally sensitive
areas. The intent is to provide a variety of stable and attractive, well -
designed housing choices that are located near transit, employment,
shopping and recreational facilities, and meet the needs of existing and
future City residents. Redevelopment of existing housing complexes is
encouraged.
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i and Use Zone
Description
King County
Urban Residential R-6
The purpose of the urban residential zone (R) is to implement
comprehensive plan goals and policies for housing quality, diversity and
affordability, and to efficiently use urban residential land, public services
and energy.
Urban Residential R-24
The purpose of the urban residential zone (R) is to implement
comprehensive plan goals and policies for housing quality, diversity and
affordability, and to efficiently use urban residential land, public services
and energy.
4.4 1 1 1 Future V..and Use
The Growth Management Act (GMA) (WSL 2024a) requires comprehensive plans to identify areas of use
to accommodate the building intensities and the future population targets of the City. Recreation, open
space, and public facilities are all considered during planning of future land use. The affected
environments of the proposed Alternatives are not within areas identified in the City's Comprehensive
Plan that will have changes to zoning, shorelines use designations, or recreation. The future land use
environments for the proposed Alternatives are consistent with current uses and designations.
4.4.1.2 Shoreline Use
The Shoreline Management Act (Chapter 90.58 RCW) (WSL 2024b) is implemented at the local through
local jurisdictions' Shoreline Master Programs (SMPs) (City 2020). Local governments develop SMPs
based on the act and state guidance, and the state ensures that local SMPs consider statewide public
interests. The SMP Shoreline Management Act generally applies shorelines and the upland areas within
200 feet of the shoreline. The Duwamish River is a shoreline, and Tukwila SMP provides policies and
regulations for activities within shoreline jurisdiction.
Shoreline environment designations are classification of shoreline areas that reflect local shoreline
conditions, including ecological functions and shoreline development (City 2020). Environment
designations provide "the framework for implementing shoreline policies and regulatory measures
specific to the environmental designation" [WAC 173-26-191(1)(d)]. Tukwila's SMP (City 2020) identifies
two shoreline designations within a 200-foot buffer of the proposed Project Alternatives and their
associated truck routes:
• Shoreline Residential- Zoned for Residential Uses and land use is currently
predominantly residential or developable land;
• Urban Conservancy- Zoned for Open Space or has a high proportion of undevelopable
land such as wetlands, steep slopes, or large parks.
According to the Tukwila Shoreline Master Program (City 2020), the purpose of the Shoreline Residential
environment is to accommodate urban density residential development, appurtenant structures, public
access, and recreational activities. The purpose of the Urban Conservancy environment is to protect
ecological functions where they exist in urban and developed settings, and restore ecological functions
where they have been previously degraded, while allowing a variety of compatible uses.
4.4.1.3 Recreation
Public recreational areas included in this EIS are open spaces designated as parks, trails, preserves, sites,
natural areas, and greenways. There is one non-public recreational facility discussed in this section, the
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Seattle Police Athletic Association is a non-profit, membership -based organization that is entirely
separate from, and independent of, the Seattle Police Department and the City of Seattle (SPAA 2024).
Below are the goals of the City of Tukwila Parks, Recreation, and Open Space Plan (PROS)(City 2019):
1. Parks, recreation, and open spaces are part of a convenient and connected System
2. The parks and recreation system builds a sense of community
3. Parks, recreation opportunities, and public services offer opportunities for all regardless of age,
abilities, and cultures
4. Parks and facilities are well maintained, clean, safe, inviting, and affordable
5. Parks, recreation opportunities, and open spaces promote healthy, active lifestyles, are
designed and managed to engage and enhance the natural environment and the local
economy.
The City of Tukwila maintains green spaces and organizes environmental programs and volunteer
opportunities through the parks system to maintain a connected and healthy community. The City has
partnered with the Green Cities Partnership, a collaboration of Puget Sound cities working to steward
natural open spaces; Tukwila's program is called the Green Tukwila Partnership (City 2024c). The seven
recreational areas listed below (and shown in Figure 4.4-2, Figure 4.4-4, Figure 4.4-6, Figure 4.4-8, and
Figure 4.4-10) may occur within a 200-foot buffer of one of more of proposed Project Alternatives and
their associated truck routes:
4.4.1..3.1. Duwamish River
The Duwamish River is a central feature in the Allentown neighborhood for both recreational and
environmental reasons. Tukwila residents have a strong connection with the river and desire expanded
choices to access and enjoy the river (City 2024d). River access includes all of the places where people
can physically access or view the river, including boat launches and docks, water access points, and
fishing areas. Each of the proposed Alternatives include buffers that overlap with views of, or access to,
the Duwamish River.
In addition to individual recreational opportunities, there are organizations and clubs that provide group
and community engagement focused on the Duwamish River, such as the Duwamish Rowing Club and
the Duwamish Alive! Coalition. These organizations welcome people of all ages and skill level to learn
about and participate in activities such as rowing, canoeing, kayaking, boating, and fishing.
4.4.1..3.2. Duwamish Hill Preserve
Duwamish Hill Preserve is located on South 115th Street, at the north end of the BNSF Intermodal
Facility, and is adjacent to the Duwamish River. This 10.5-acre park is on land that is of historical,
cultural, and ecological significance in Tukwila (City 2024d). Due to its elevated position above the
Duwamish River, the hill offered a vantage point from which Native Americans could watch for incoming
groups and communicate with fellow tribe members along the Duwamish River Valley (City 2024d). The
preserve includes an outdoor classroom area, the Cultural Garden, and enhanced trail system.
Duwamish Hill Preserve is managed as a public open space preserve dedicated to the conservation and
enhancement of its rich Native American cultural history, ecological importance, and community impact
(City 2024d).
157
4.4.1..3.3 Green River Trail
The Green River Trail is an extensive, paved regional trail that lies on the west and south banks of the
Duwamish River throughout much of the Allentown neighborhood. Not only does the Green River Trail
offer opportunities for recreation, but it is also a commuting corridor for many of the workers in the
local business parks. Users of the trail can take advantage of multiple locations to launch small
watercraft, fish, and view wildlife. As part of the King County Regional Trails System, it increases mobility
and access for residents to connect to other communities and to commercial areas (King County 2024c).
4.4.1..3.4 Seattle Police Athletic Association
The Seattle Police Athletic Association (SPAA) is a non-profit, membership -based organization that is
entirely separate from, and independent of, the Seattle Police Department and the City of Seattle (SPAA
2024). Since 1943, the SPAA has maintained an approximately 30-acre outdoor firearm training facility
at the northwest end of the BNSF Intermodal Facility. This recreation and training facility is zoned as
heavy Manufacturing or Industrial Center due to inherent noise and safety reasons of the firearms
training center. Although the SPAA is private and is not zoned as a park or public recreation area, it is
being considered in the EIS as a recreation location because it maintains a green space and attracts
visitors to this special attraction within the city.
4.4.1..3.5 Tukwila Community Center
The Tukwila Community Center is located near the corner of 42nd Avenue South and South 124th
Street. The community center is on a parcel that is approximately 12.3 acres with approximately 1,050
feet of frontage along the Duwamish River (City 2024d). The Tukwila Community Center is easily
accessible by public transportation and has indoor and outdoor facilities. Indoor facilities include
meeting rooms, classrooms, a banquet facility with a commercial kitchen, a gym and fitness center,
locker rooms, and showers. Outdoor facilities include a picnic shelter, picnic tables and grills, a
playground, basketball hoops, ball fields, an open playfield, a skate park, a spray park, a restroom, and
walking paths. The Community Center is the hub for community events hosting community play days,
organized sports, clubs, and classes. The Center also organizes trips, holiday celebrations, and health
and social programs.
4.4.1..3.6 Codiga Park
Codiga Park is located at the south end of the BNSF Intermodal facility between 50th Place South and the
Duwamish River. This park is located on a bend in the Duwamish River; it is a partially restored tidal
wetland that was previously a dairy farm (City 2024d). This 6.75-acre park provides public amenities
such as access to the river and the Green River Trail, and has a picnic shelter and picnic tables. Through
the Shoreline Master Program (2020) the City of Tukwila identifies Codiga Park as a fish and wildlife
habitat conservation area that requires a 100-foot buffer from development along the shoreline of the
park boundary.
4.4.1..3.7 West Skyway Natural Area
The West Skyway Natural Area is an unimproved, vacant, 3.2-acre parcel of land managed by King
County. This natural, densely vegetated area is at the south end of the BNSF Intermodal Facility and is
bordered by 1-5, the BNSF ROW, South 129th Street, and Beacon Coal Mine Road. This area is not a
formal park or recreational area, but provides natural landscape and a buffer to the interstate and rail
traffic to the residents along South 129th Street (King County 2022a).
158
4.42 Relevant Plans, Policies, and Regulations
The relevant plans, policies, regulations, and guidance consulted when analyzing the potential impacts
of the proposed Alternatives are described in Table 4.4-2.
Toble 4.4 2. Relevant Nuns, Policies, ond Regulations
State
Growth Management Act (GyWA)
Requires all cities and counties inWashington toadopt
development regulations that protect critical areas,
including shorelines.
Shoreline Management Act of1971Chapter
90.58RCVV
Permitted uses inthe shorelines ofthe state shall be
designed and conducted inumanner tominimize, insofar
as practical, any resultant damage tothe ecology and
environment ofthe shoreline area and any interference
with the public's use ofthe water.
Washington State Shoreline Master Program.
VVAC 173'26'191
Shoreline master programs are both planning and
regulatory tools. Master programs balance and integrate
the objectives and interests oflocal citizens, they address
the full variety ofconditions onthe shoreline, and they
consider and, where necessary toachieve the objectives
ofchapter 9O.58RCVV influence planning and regulatory
measures for adjacent land. Master programs address
conditions and opportunities ofspecific shoreline
segments byclassifying the shorelines into "environment
designations" usdescribed inVVAC173'26'211.
Local
City ofTukwila Comprehensive Plan (2O15)
Acomprehensive plan isubroad statement ofcommunity
goals and policies that direct the orderly and coordinated
physical development ofucity into the future. |treflects
current community goals and needs, anticipates change,
and provides specific guidance for future legislative and
administrative actions. |treflects the results ofpublic
involvement, technical analysis, and the judgment of
decision makers.
King County Critical Areas Ordinance (King
County Code [KCC]21A)
This ordinance was developed under the directives ofthe
GyWAtodesignate and protect critical areas and toassist
inconserving the value ofproperty, safeguarding the
public welfare, and providing protection for these areas.
King County Open Space Plan (2O22b)
This plan provides uframework guiding King County in
the planning, development, stewardship, and
management ofits complex system of2OOparks, 175
miles ofregional trails, and 2O6OOOacres ofopen space.
King County Zoning Code Title 21AKCC
This code encourages land use decision making, promotes
orderly development, provides adequate public facilities
and services, promotes public safety by regulating
development oflands containing physical hazards, and
minimizes adverse environmental impacts of
development.
159
l aw, Regulation, or Guidance
Description
City of Tukwila Environmentally Critical Areas
TMC 18.45
The purpose of TMC Chapter 18.45 is to protect the
environment, human life and property; to designate and
classify ecologically critical areas including but not limited
to regulated wetlands and watercourses and geologically
hazardous areas and to protect these critical areas and
their functions while also allowing for reasonable use of
public and private property. These regulations are
prepared to comply with the Growth Management Act.
Tukwila Zoning Code Title 18 TMC
This code encourages land use decision making, promotes
orderly development, provides adequate public facilities
and services, promotes public safety by regulating
development of lands containing physical hazards, and
minimizes adverse environmental impacts of
development.
City of Seattle Environmentally Critical Areas
SMC 25.09
The purpose of Chapter 25.09 to provide for and promote
the health, safety and welfare of the general public, and
to not create or otherwise establish or designate any
particular person, or class, or group of persons who will
or should be especially protected or assisted by the terms
or provisions.
Seattle Zoning Code Title 23 SMC
This code encourages land use decision making, promotes
orderly development, provides adequate public facilities
and services, promotes public safety by regulating
development of lands containing physical hazards, and
minimizes adverse environmental impacts of
development.
City of Tukwila Parks, Recreation, and Open
Space Plan (2019)
The Parks, Recreation and Open Space (PROS) Plan
provides a comprehensive guide for the parks, recreation
and open space system, and plays a major role in
supporting the citywide vision of Tukwila's Strategic
Plan.
City of Tukwila Ordinance 2625: Critical Areas
Regulations (2020)
Regulations that protect the functions of sensitive areas,
including wetlands, watercourse, fish and habitat
conservation areas, and areas of potential geological
instability
City of Tukwila Ordinance 2626: Tukwila
Shoreline Master Program (SMP) (2020)
The SMP is intended to guide new shoreline
development, redevelopment, and promote
reestablishment of natural shoreline functions, where
possible.
Zoning, City of Burien Municipal Code (BMC)
Title 19
This code encourages land use decision making, promotes
orderly development, provides adequate public facilities
and services, promotes public safety by regulating
development of lands containing physical hazards, and
minimizes adverse environmental impacts of
development.
160
4.4.3 Methodology
In this Section of the EIS, the potential impacts of the proposed Project on the land and shoreline use
and recreation resources are analyzed and evaluated under the guidelines of the City's values and the
City's, County's, and State's management plans, ordinances, acts, and laws. The proposed Alternatives
and their associated traffic routes (excluding highways), plus a 200-foot buffer, were used in analyzing
the potential impacts of the Alternatives on the space that they would occupy and their effect on
adjacent properties.
Impacts to land use were evaluated by analyzing how the proposed Project would fit within existing
zoning codes, and how, and to what extent, the proposed Project Alternatives could impact the City's
future plans for the land use. Shoreline use was analyzed by examining the current shoreline
designations and the types of development or redevelopment may be permittable in those locations.
The proposed Project Alternatives were also analyzed for their potential impacts to recreation; this
resource was evaluated qualitatively based on the goals of the City of Tukwila PROS Plan.
4.4.4 Impacts Analysis
In this sub -section, the proposed Alternatives are analyzed in turn in respect to the resources of Land
Use, Shoreline Use, and Recreation. The impacts for Land Use, Shoreline Use, and Recreation are
evaluated by using the definitions listed in Table 4.4-3.
Table 4.4-.3. Impact Magnitude and Description
Magnitude of Impact
Description
No Impact
The proposed Project would be fully consistent with the intent of applicable
land use, shoreline use, or recreation plans and policies.
Minor
The proposed Project would result in short-term temporary impacts, or minimal
long-term impacts to land use, shoreline use, or recreation resources.
Moderate
The proposed Project would result in long-term or permanent impacts to
recreation, land use, or shoreline use, but mitigation can be applied to reduce
the impact to be less than significant.
Significant
The proposed Project would cause long-term, permanent, or irreversible
inconsistencies with applicable land use or recreation plans and policies or the
zoning codes.
The impacts from both construction and operations for these resources are analyzed, and a summary of
the magnitude of impacts is presented at the end of Section 4.4.4 in Table 4.4-4.
4.4.4.1 No Action Alternative
A detailed description of the No Action Alternative components and routes are provided in Section 3.4.
Figure 4.4-1 shows zoning, and Figure 4.4-2 shows shoreline designation, parks, trails, and recreational
facilities within and adjacent to the No Action Alternative.
161
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4.4.4 1 1 Land Use
4.4.4.1.1.1 No Action Construction Impacts to Land Use
Construction impact analysis is not applicable because the No Action Alternative is the current operating
condition of the BNSF Intermodal Facility and the truck transportation route.
4.4.4.1.1.2 No Action Operations Impacts to Land Use
The truck route for the No Action Alternative includes travel along Interurban Avenue South where the
adjacent properties are zoned as Commercial Light Industrial (CLI) (City 2024a). Continued use of this
roadway and ramps onto 1-5 would be consistent with current zoning, and therefore, would have No
Impact on Land Use.
However, the truck route for the No Action Alternative travels along 42nd Avenue South and South 124th
Street. The route and adjacent properties are zoned as Low Density Residential (LDR), Residential
Commercial Center (RCC), and Regional Commercial Mixed Use (RCM); refer to Table 4.4-1 for Land Use
District descriptions. The continued heavy truck traffic throughout the LDR and RCC zoned areas create a
Significant impact because residential areas are not zoned for industrial -level traffic. The No Action
Alternative is not consistent with current land use plan TMC 18.60.060, and it would cause long-term or
irreversible inconsistencies with LDR zoning which is intended to maintain stable residential
neighborhoods and to prevent intrusions by incompatible land uses such as for industrial or
manufacturing purposes.
4.4.4.1.2. Shoreline Use
4.4.4.1.2.1 No Action Construction Impacts to Shoreline Use
Construction impact analysis is not applicable because the No Action Alternative is the current operating
condition of the BNSF Intermodal Facility and the truck transportation route.
4.4.4.1.2.2 No Action Operation Impacts to Shoreline Use
Shoreline Use within and adjacent to the truck route for the No Action Alternative is designated as
Urban Conservancy and Shoreline Residential (City 2024a). The impacts to Urban Conservancy shoreline
would be No Impact as this designation allows for multiple uses. The impacts to the Shoreline
Residential designation would be Moderate because continuing trucking operations would disrupt the
intent of the Shoreline Management Act which states that Shoreline Residential areas are to
accommodate residential development and structures and to support recreation, not to support
industrial activities such as heavy trucking. Mitigation could be implemented to reduce the impact to a
minor level.
4.4.4.1..3 Recreation
4.4.4.1.3.1 No Action Construction Impacts to Recreation
Construction impact analysis is not applicable because the No Action Alternative is the current operating
condition of the BNSF Intermodal Facility and the truck transportation route.
4.4.4.1.3.2 No Action Operation Impacts to Recreation
The truck route for the No Action Alternative passes over the Green River Trail on an existing vehicle
bridge; this alternative would have a Minor impact to recreation along the trail.
164
The No Action truck route also follows 42nd Avenue South and South 124th Street; it impacts the majority
of pedestrian and vehicle access points to the Tukwila Community Center (Figure 4.4-2). The continued
operation of this alternative does not follow the City's Parks, Recreation, and Open Space Plan because
the heavy trucking traffic impedes convenient and connected access, it disrupts a sense of community,
and it does not promote safe and inviting access to this recreation facility. Impacts of the No Action
Alternative on Recreation would be Significant.
4.4.4.2 Alternative 2: Airport Way South
A detailed description of this proposed Alternative's components and routes are provided in Section
3.3.1. Figure 4.4-3 shows the zoning, and Figure 4.4-4 shows the shoreline designation, parks, and
recreational facilities within and adjacent Alternative 2.
4.4.4.2..1. Land Use
4.4.4.2.1.1 Alternative 2 Construction Impacts to Land Use
The proposed construction area for Alternative 2 is zoned as Manufacturing Industrial Center/ Heavy
(MICH/H) within the City of Tukwila (City 2024a), as Industrial (MML U/85, MML U/65) within the City of
Seattle (SDCI 2024), and as Residential (Rs-7,200, RM-18) in the City of Burien (Burien 2019); refer to
Table 4.4-1 for Land Use District descriptions. The truck entrance and operations yard for Alternative 2
would be located on City of Seattle government owned parcels. The current Police Athletic Association
training facility would need to be relocated for construction of Alternative 2 to occur. While the land use
of parcels 032304-9030 and 032304-9099 would change from a members -only recreation facility in an
industrial area to a private, restricted access industrial facility, these parcels would not require rezoning
for the Project. Construction of new access and an operations yard for the BNSF Intermodal Facility in
this area would be consistent with zoning regulations and future land use designations. Therefore, the
construction of Alternative 2 would have No Impact on Land Use.
4.4.4.2.1.2 Alternative 2 Operations Impacts to Land Use
The proposed truck travel route for Alternative 2 would not occur in residential areas; heavy vehicles would be
routed through MIC/H, Manufacturing Industrial Center/ Light (MIC/L), and Light Industrial (LI) zones and
along Interstate, State Road, and access road rights -of -way (City 2024a). Operation of new access and an
operations yard for the BNSF Intermodal Facility in this area would be consistent with current and
planned zoning regulations. Therefore, the construction of Alternative 2 would have No Impact on Land
Use.
4.4.4.2..2. Shoreline Use
4.4.4.2.2.1 Alternative 2 Construction Impacts to Shoreline Use
The construction area for Alternative 2 does not overlap with a Shoreline Use Area or buffer. Analysis of
impacts from construction on Shoreline designations in not applicable.
4.4.4.2.2.2 Alternative 2 Operations Impacts to Shoreline Use
The truck route for Alternative 2 would travel along East Marginal Way South, Tukwila International
Boulevard, and SR 99 which overlap, in parts, with Urban Conservancy shoreline (City 2024a). There
would be No Impact to Urban Conservancy shoreline as the truck route would follow an existing, high -
traffic road that carries heavy trucks to and from multiple industrial destinations.
165
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4.4.4.2.3.1 Alternative 2 Construction Impacts to Recreation
The truck entrance and operations yard for proposed Alternative 2 would be located on city owned
lands that has hosted Seattle Police Athletic Association (SPAA) for over 80 years, see Figure 4.4-4. The
removal of the SPAA to accommodate a new BNSF operations yard would be a Significant impact
because this popular, historic recreational facility would be permanently removed, affecting both
civilian and law enforcement users. Potential mitigation for this impact is described in Section 4.4.5.
Impacts to Noise from the potential replacement of this firearms recreation facility with the BNSF
intermodal facility operations yard are discussed in Section 4.10.
4.4.4.2.3.2 Alternative 2 Operations Impacts to Recreation
The northern border of the Duwamish Hill Preserve is not within the 200-foot buffer of Alternative 2, see
Figure 4.4-4. Although the operations of Alternative 2 would not directly impact the Preserve, it could
potentially impact the sense of open space and could detract from the sense of a natural environment
to visitors to the Preserve. As a result, operations impact to the Duwamish Hill Preserve could be Minor,
rather than 'none' or 'not applicable'. Potential mitigation for this impact is described in Section 4.4.5.
The Green River Trail would be adjacent to the truck route for Alternative 2 for approximately 350 feet
as both the truck traffic and trail would use the Tukwila International Boulevard bridge to cross the
Duwamish River, see Figure 4.4-4. The proposed truck route would cross over the Green River Trail on
the south bank of the Duwamish River via the Tukwila International Boulevard bridge. Operations
Impacts to the Green River Trail would be Minor because the truck traffic would be travelling along an
existing high -volume roadway and would not alter the existing means or ability to access this
recreational area. Potential mitigation for this impact is described in Section 4.4.5.
4.4.4..E Alternative 3B: Improvements to 48th Place South
A detailed description of this proposed Alternative's components and routes are provided in Section
3.4.2. Figure 4.4-5 shows the zoning, and Figure 4.4-6 shows the shoreline designation, parks, and
recreational facilities within and adjacent to Alternative 3B.
168
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4.4.4.3.1.1 Alternative 3B Construction Impacts to Land Use
The proposed construction area for Alternative 3B is zoned as Manufacturing Industrial Center/ Light
(MIC/H), Commercial Light Industrial (CLI), and Low Density Residential (LDR) (City 2024a); refer to Table
4.4-1 for Land Use District descriptions. The truck entrance for Alternative 3B would be located on BNSF
parcels, and the access ramps and other new construction for this alternative would occur within the
Gateway Corporate Center and along the road right-of-way of Railroad Avenue. The majority of
construction for this alternative would occur within MIC/H and CLI designated areas which would result
in No Impact to Land Use in those areas. However, the western access ramp along Railroad Avenue
would be constructed within a Low -Density Residential area, which would result in Minor impacts to
Land Use during the construction phase of this proposed Alternative.
4.4.4.3.1.2 Alternative 3B Operations Impacts to Land Use
The proposed truck travel route for Alternative 3B would not occur in residential areas; heavy vehicles
would be routed through CLI and RCM zones and along Interstate, State Road, and access road rights -of -
way. The western ramp that is proposed for the access intersection on Railroad Avenue will be for
residential traffic only for east -west travel along Railroad Avenue; this ramp that extends into LDR-zoned
land will not be used by truck traffic to enter or exit the BNSF South Seattle Facility.
The Land Use during operations for Alternative 3B would be consistent with current land uses within the
CLI, MIC/HI zones, and Recreational Area. During operations, there would be no impact to land use in
the MIC/HI zone. Truck traffic would increase in the CLI designated area which could result in Moderate
impacts to land use, as the truck traffic associated with the BNSF facility would not be characterized as
light industrial. Potential mitigation for this impact is described in Section 4.4.5.
4.4.4.3.2. Shoreline Use
4.4.4.3.2.1 Alternative 3B Construction Impacts to Shoreline Use
The construction of Alternative 3B would occur within the buffers of Urban Conservancy and Residential
Shoreline designations (City 2024a). The impacts to Urban Conservancy and Residential Shoreline would
be Moderate because construction would introduce new infrastructure to the Urban Conservancy
shoreline. Vehicle bridges are permitted under the Urban Conservancy and Shoreline Residential
designations only if the bridge connects public right-of-way (TMC 18.44); therefore, the new bridge
would be consistent with shoreline use, but would create new disturbance. With mitigation, these
impacts could be reduced to the Minor level. Potential mitigation for this impact is described in Section
4.4.5.
4.4.4.3.2.2 Alternative 3B Operations Impacts to Shoreline Use
Proposed Alternative 3B would span the Duwamish River. The main ramps, retaining walls, and new
bridge abutments for the dedicated truck entrance/exit from the BNSF Intermodal Facility would be
located within and over Urban Conservancy shoreline and buffer areas. A retaining wall and ramp from
the new intersection of the truck access with Railroad Avenue would be located within the Residential
Shoreline designation and buffer. Because the purpose of Urban Conservancy is to protect and restore
ecological functions of open space while allowing for multiple uses, operations of Alternative 3B would
introduce new bridge infrastructure to the shoreline areas instead of restoring ecological functions.
171
While building a new vehicle bridge over water that connects public right-of-way is permittable by the
Tukwila Municipal code and the Tukwila Shoreline Master Program, the operation of Alternative 3B
would have long term impacts to Shoreline Use due to the presence of new infrastructure. Therefore,
there would be a Moderate impact on Shoreline Use for the operations of Alternative 3B. With
mitigation, these impacts could be reduced to the Minor level; potential mitigation for this impact is
described in Section 4.4.5.
4.4.4.3.3 Recreation
4.4.4.3.3.1 Alternative 3B Construction Impacts to Recreation
The truck access and redesigned Railroad Avenue intersection for proposed Alternative 3B would occur
within the recreational areas of the Duwamish River, Green River Trail, and Codiga Park. Impacts to
these recreational areas during construction would be Moderate as recreationists and commuters along
the trail would be detoured or deterred for this phase of the proposed Project. With mitigation, these
impacts could be reduced to the Minor level; potential mitigation for this impact is described in Section
4.4.5.
4.4.4.3.3.2 Alternative 3B Operations Impacts to Recreation
Impacts to public of the Duwamish River, Green River Trail, and Codiga Park would be No Impact to
Minor as features of the new bridge might alter the landscape of the Duwamish River, Green River Trail,
and Codiga Park, but they would meet the goals of the City of Tukwila Parks, Recreation, and Open
Space Plan to have a connected System and to engage the local economy. The new bridge and
redesigned roadways would be constructed with sidewalks; residents would be able to more easily
access the Green River Trail from Codiga Park by crossing the Duwamish River via the new bridge for
proposed Alternative 3B.
4.4.4.4 Alternative 4: New Bridge from SR 900 (MLK Jr Way) to South 129th Street
A detailed description of this proposed Alternative's components and routes are provided in Section
3.4.3. Figure 4.4-7 and Figure 4.4-9 show the zoning, and Figure 4.4-8 and Figure 4.4-10 show shoreline
designation, and parks and recreational facilities within and adjacent to Alternative 4.
172
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4.4.4.4.1. Land Use
4.4.4.4.1.1 Alternative 4 Construction Impacts to Land Use
The proposed construction areas for Alternative 4 are zoned as Low Density Residential (LDR), High
Density Residential (HDR), Manufacturing Industrial Center/ Heavy (MIC/H), Commercial Light Industrial
(CLI), and Heavy Industrial(HI) (City 2024a).The southern portion of proposed Alternative 4 is located in
Skyway -West Hill and Tukwila. Skyway -West Hill is an urban unincorporated area in King County
southeast of Seattle, northeast of Tukwila, and northwest of Renton, Washington (King County 2022a).
The parcels of land in Alternative 4 that are in Skyway -West Hill (King County) are zoned as Urban
Residential (R-6 and R-24). Refer to Table 4.4-1 for Land Use District descriptions.
The truck entrance for proposed Alternative 4 would be located on BNSF parcels zoned as MIC/H, and
on land zoned as, and currently occupied by residential housing. Six parcels on the east side of 51"
Street Place South would need to be rezoned from LDR to MIC/H. Five of the parcels are owned by
BNSF, and parcel 0179002255 is a privately owned 5-bedroom, 2.5-bathroom residence (King County
2024d). The residents of this home would be directly displaced by the construction of Alternative 4. The
parcels of privately -owned lands in Skyway -West Hill are vacant, however, and residents would not be
displaced by the acquisition of these parcels for the construction of the new connecting access road
from SR 900 to South 129th Street within a new right-of-way or easement for Alternative 4. Additionally,
two vacant parcels in the northern portion of proposed Alternative 4 are zoned as LDR and HDR. These
parcels would need to be acquired partially or in full to construct the access road improvements for
trucks to enter and exit SR 900.
Because the proposed Project would need to acquire full or partial parcels of privately -owned lands, and
change the land use zoning on those parcels from Residential to Industrial, Alternative 4 would have
Significant impacts to Land Use.
4.4.4.4.1.2 Alternative 4 Operations Impacts to Land Use
The impacts to Land Use from the operation of Alternative 4 would be identical to the construction
impacts. Because the proposed Project would need to acquire full or partial parcels of privately -owned
lands, and change the land use zoning on those parcels from Residential to Industrial, Alternative 4
would have Significant impacts to Land Use.
4.4.4.4.2. Shoreline Use
4.4.4.4.2.1 Alternative 4 Construction Impacts to Shoreline Use
The construction of Alternative 4 would occur within Urban Conservancy shoreline and buffer area, and
within the buffer area for Residential Shoreline (City 2024a). The impacts to Urban Conservancy and
Residential Shoreline would be Moderate because construction would introduce new infrastructure to
the Urban Conservancy shoreline with the construction of the BNSF facility ingress/egress ramps and the
widening of the South 129th Street bridge. With mitigation, these impacts could be reduced to the Minor
level. Potential mitigation for this impact is described in Section 4.4.5.
4.4.4.4.2.2 Alternative 4 Operations Impacts to Shoreline Use
Proposed Alternative 4 would be located within Urban Conservancy shoreline and buffer area, and
within the buffer area for Residential Shoreline. There is existing roadways and infrastructure in the
proposed locations, and the operation of proposed Alternative 4 would not be inconsistent with the
177
current or planned use of these shoreline designations. Therefore, after construction, impacts on
Shoreline Use for the operations of Alternative 4 would be Minor. Potential mitigation for this impact is
described in Section 4.4.5.
4.4.4.4.3 Recreation
4.4.4.4.3.1 Alternative 4 Construction Impacts to Recreation
The 200-foot buffer for Alternative 4 overlaps with the West Skyway Natural Area. Construction will not
disturb this natural area; there will be No Impact to recreation for this location.
The right-of-way for 50th Place South overlaps with the boundaries of Codiga Park. Construction for
proposed Alternative 4 would require making improvements to this road in the vicinity of the proposed
entrance to the BNSF facility. Impacts to recreation at Codiga Park during construction would be Minor
as recreationists and would be detoured or delayed from using the park's east entrance due to
construction activities for this phase of the proposed Project.
4.4.4.4.3.2 Alternative 4 Operations Impacts to Recreation
The West Skyway Natural Area is within the 200-foot buffer for Alternative 4. No part of the proposed
Alternative will fall within the natural area. This location is an undeveloped green space with no
recreational facilities. Alternative 4 would not result in ground disturbance to this green space, and the
West Skyway Natural Area would continue to provide green space and environmental enjoyment.
Alternative 4 would have No Impact on the West Skyway Natural Area.
Heavy vehicle traffic for BNSF intermodal facility would not be using 50th Place South as an access route.
The entrances to the Codiga Park are not within the truck route, and visitors to the park would not need
to cross in front of truck traffic to access the park. Once the construction phase is complete for proposed
Alternative 4, impacts to recreation at Codiga Park would be Minor as there would be increased traffic
to the area which may intermittently affect enjoyment of the natural environment. Potential mitigation
for this impact is described in Section 4.4.5.
4.4.4.5 Summary of Impacts per Alternative
A summary of the impacts for Land Use, Shoreline Use, and Recreation for the proposed Project
Alternatives is presented in Table 4.4-4.
Table 4.4•-4. Impact Summary Table
Magnitude of Impacts'
Alternative
Phase
Land Use
Shoreline Use
Recreation
No Action
Construction
N/A
N/A
N/A
Operation
Significant
Moderate
Significant
2
Construction
No Impact
N/A
Significant
Operation
No Impact
No Impact
Minor
3B
Construction
Minor
Moderate
Moderate
Operation
Moderate
Moderate
Minor
4
Construction
Significant
Moderate
Minor
Operation
Significant
Minor
Minor
1 If a resource has more than one magnitude, the highest level is used in this chart for conservative comparison
178
4.4.5 Mitigation Measures
As part of the SEPA process, if an Alternative is determined to have negative impacts, possible mitigation
measures must be presented to support minimizing the impacts to the greatest extent (WAC 197-11-768).
4.4.5.1 No Action Alternative
The No Action Alternative represents the current operating conditions of the BNSF -related heavy
vehicle traffic through the Allentown neighborhood of Tukwila. Feasible mitigation measures are
presented in this EIS as Alternatives 2, 3B, and 4.
4.4.5.2 Alternative 2: Airport Way South
Alterative 2 would not have an impact on Land Use or Shoreline designations.
Recreation would be significantly impacted by the removal of the Seattle Police Athletic Association
facility. Mitigation for this impact could include relocating the recreational facility to another suitable
location within the City of Tukwila.
The impacts to Duwamish Hill Preserve would be minor and would not directly affect access to or the
nature of the Preserve. However, mitigation for the possible impacts of the BNSF operations yard could
include constructing a decorative and noise -reducing wall or mound and/or installing attractive and
disguising landscaping at the south end of the new operations yard.
Similarly, there would be no direct impacts to the Green River Trail from implementing Alternative 2, but
mitigation measures can be put into effect to enhance the user experience. Barriers between the
sidewalk and the traffic lanes on the Tukwila International Boulevard bridge could be visually and
structurally improved, and hazard awareness signage for pedestrians and vehicles alike could be
installed.
4.4.5..E Alternative 3B: Improvements to 48th Place South
The Moderate impacts to Land Use from implementing Alternative 3B would stem from the presence of
an increased volume of industrial truck traffic in Gateway Corporate Park and the interaction of this new
traffic element in an office and light industrial area. This impact could be mitigated by including
additional traffic control engineering. Mitigation could include improved pedestrian crossings and
signage, installing a green strip and setting back the sidewalks from the street, and/or redesigning the
parking lot entrance of the office building at 13075 Gateway Drive South. If one of the entrances to this
office building is relocated to Gateway Drive from 57th Avenue South, there would be fewer impacts of
heavy vehicle traffic on land use of the business park.
The new bridge across the Duwamish River would result in Moderate impacts to Shoreline Use and
Recreation. The impact to open space and natural environment can be mitigated in the following ways:
• Minimization of impact: During construction, new ground disturbance would be kept to a
minimum within a clearly defined and monitored limit of disturbance. Best Management
Practices will be used to minimize erosion and compaction. The construction teams would
follow spill control and Stormwater Pollution Prevention plans.
• Rectification of impact: After construction, the area of construction can be rehabilitated to
restore riparian vegetation and aquatic habitats.
179
• Compensation for impact: Instead of constructing a purely utilitarian bridge, the bridge could be
designed to be an attractive local feature or an architectural landmark for the City. This kind of
infrastructure adds visual interest to commuters and recreationists and can become a defining
feature. Like many cities with well -designed and recognizable bridges, beautiful design can
enhance the city's culture and identity.
• Reduction of impact: The impact of the new bridge on Recreation can be reduced by including it
in part of the recreation trails and systems. Instead of detracting or subtracting from the
established recreational facilities, the bridge can be included as part of the trail system. The
pedestrian sidewalks along the bridge can be made without steps so that cyclists can travel from
the Green River Trail to Codiga Park without needing to dismount. New signs can direct trail and
park users of the new route. As with the barriers and safeguards along the Tukwila International
Boulevard bridge, the new bridge across the Duwamish could include pedestrian and cyclist
safety features.
4.4.5.4 Alternative 4: New Bridge from SR 900 (MLK Jr Way) to South 129th Street
The impacts to Land Use for Alternative 4 would be significant. Potential mitigation for this impact
would be monetary compensation and/or assistance with relocation for displaced residents.
4.4.6 Significant Unavoidable Adverse Impacts
The impacts analyzed for the Land Use, Shoreline Use, and Recreation section that were determined to
be Significant would be avoidable by selecting another Alternative. As there is no preferred alternative
for this analysis, the impacts must be weighed against each other equally rather than in relation to a
"standard". Each of the Alternatives presented in this analysis have trade-offs; they affect the resources
in different ways and to different degrees. The purpose of this Environmental Impact Statement is to
find an alternate solution to the current operating conditions of the traffic related to the BNSF facility- a
solution that will reduce truck traffic in residential and recreational areas.
180
4.5 Air QuaDhty and Greenhouse Gas
4.5.1 Affected Environment
Ambient "air quality" refers to the condition of the outdoor air within our environment. Good ambient
air quality pertains to the degree to which the air is clean, clear, and free from pollutants such as smoke,
dust, and gaseous impurities in the air. Air quality is determined by the concentration of various
pollutants in the atmosphere. The main pollutants of concern are called criteria pollutants and toxic air
pollutants. The criteria pollutants that are regulated nationwide via National Ambient Air Quality
Standards (NAAQS) consist of carbon dioxide (CO), ozone (03), nitrogen dioxide (NO2), sulfur dioxide
(SO2), lead (Pb), and particulate matter including particulate matter less than 10 microns in diameter
(PM10) and less than 2.5 microns in diameter (PM25). The regulated toxic pollutants are from a list of 187
chemical compounds designated by the United States Environmental Protection Agency (EPA) and over
400 toxic pollutants designated by the state and local air quality agency as posing cancer or other
human health risks. EPA identified nine compounds with significant contributions from mobile sources
that are among the national and regional -scale cancer risk drivers or contributors and non -cancer hazard
contributors from the 2011 National Air Toxics Assessment. These priority air toxics are 1,3-butadiene,
acetaldehyde, acrolein, benzene, diesel particulate matter, ethylbenzene, formaldehyde, naphthalene,
and polycyclic organic matter, which are a subset within what is called Mobile Source Air Toxics (MSAT).
While the Federal Highway Administration (FHWA) considers these the priority MSAT, the list is subject
to change and may be adjusted in consideration of future EPA rules.
4.5.1.1 Study Area
The study area for evaluating impacts on air quality is within and near the Project site that could be
affected by construction and operation activities on the Project site. The Project site is in the Allentown
district of the City of Tukwila, Washington within King County. Allentown is bounded by the right-of-way
for a Seattle City Light transmission corridor to the north, 1-5 and BNSF's South Seattle Intermodal
Facility to the east, and the Duwamish River to the south and west. Land use in Allentown is mainly
zoned for low -density residential development, primarily single-family housing, along with several
neighborhood parks, the Tukwila Community Center, and the Green River Trail. Natural areas include
restored habitat in the Duwamish Hill Reserve, several small wetlands, and the Duwamish River's
riparian corridor. In addition to BNSF's South Seattle facility, nearby land uses include the Gateway
Corporate Center, single-family development in the Riverton neighborhood, and commercial
development along 48th Avenue South, consisting primarily of freight and truck -related services. Several
major transportation routes are in the vicinity of Allentown, including 1-5 to the east and south; and to
the west, SR 599, Interurban Avenue, East Marginal Way, and an elevated section of Sound Transit's Link
Light Rail line. The BNSF property is approximately 2.6 miles northeast of Seattle -Tacoma International
Airport.
For the evaluation of climate and greenhouse gases, the study area is discussed in terms of regional air
quality, as changes in climate are realized more broadly. Immediately adjacent properties to the BNSF
facility are a sliver of undeveloped land and Interstate 1-5 to the east; rail lines, overpass roads, and
undeveloped land to the north; a shooting range, residential and commercial property to the west; and
181
rail lines, overpass roads and the Duwamish River to the south. The closest schools from the location of
Alternative 3b and 4 construction areas are two schools located approximately 0.6 miles to the
northeast (Rainier View Elementary School) and another school located approximately 0.7 miles east
(Campbell Hill Elementary School). Duwamish Hill Preserve, i.e. park land, is located near to Alternative 2
and 4 construction areas, approximately 0.4 miles south and 0.3 miles southeast, respectively.
At the time of drafting this Environmental Impact Statement, no preferred alternative has been
selected. As a result, the travel demand model for the preferred alternative, which provides essential
inputs for the quantitative MOVES assessment is not yet available. Therefore, this air quality section will
discuss relevant federal and state regulations and outline how the project should proceed once that
information becomes available.
4.5 1 1 1 Area Air Quality Environment
Air quality in and around the study area, i.e., King County, has generally been good for approximately 59
percent of the year, with some moderate air quality for approximately 39 percent of the year and less
than 2 percent with unhealthy air for sensitive groups or others (PSCAA 2023). Air quality in this area is
regulated and enforced by the USEPA, Washington Department of Ecology, and the Puget Sound Clean
Air Agency (PSCAA).
One of the ambient air monitors located in King County, and considered representative of air quality at
the Allentown site, is located at 11675 44th Avenue South, Tukwila, Washington. This monitoring station
monitors for PM2.5 concentrations. The PM25design values, i.e. annual arithmetic mean concentrations
averaged over three years for demonstrating compliance, from this monitoring station for 2022 and
2023 have shown the ambient annual mean PM2.5 concentrations have been 7.2 micrograms per cubic
meter (µg/m3) and 7.3 µg/m3 compared to the current standard of 9 µg/m3. These values are
approximately 80 to 81 percent of the current standard and 60 to 61 percent of the previous standard
of 12 µg/m3. The 24-hour PM2.5 98th percentile concentration from this station for 2023 was 24 µg/m3
which is approximately 69 percent of the ambient standard; 35 µg/m3 (EPA 2025a).
4.51.12 Climate and Greenhouse Gasses (GFIG.$) Environment
"Climate" is the average weather conditions over time for a particular region, usually taken over a
period of 30 years or more. While the topic of climate can be global in nature, changes in climate for this
EIS are discussed with respect to potential impacts on regional air quality in Washington for the
proposed Project. Atmospheric warming associated with climate change has the potential to increase
ground -level ozone in many regions, which may present challenges for compliance with the ozone
standards in the future. The impact of climate change on other air pollutants, such as particulate matter,
is less certain, but research is underway to address these uncertainties.
The region around the Project site experiences a maritime climate with winters that are cool and very
wet with high temperatures averaging in the mid- to upper 40s Fahrenheit and lows near freezing. Snow
is not very common, with occurrences typically only on a few days each year. Spring has less rain and
milder temperatures, with highs regularly in the mid-50s to around 60°F. Summers are warm and dry
with highs in the 70s on most days, with some days reaching the 80s and occasionally the 90s. Summer
thunderstorms occur occasionally but are mostly isolated and rarely severe. These storms typically
originate from the Cascade Mountains and are from warm moist air from monsoonal flow in the
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southwest U.S. By fall, temperatures start to drop, and precipitation increases. The average rainfall in
the months of October to March is 4.7 to 7.9 inches per month, with the lowest rainfall between May
and September averaging between 0.7 and 2.3 inches per month. The wind direction is most often from
the north between early July and early September and most often from the south between early
September through early July. The average of the mean hourly wind speed does not vary significantly
throughout the year and varies between 2.9 to 5.4 mph (Weather Spark 2024).
Gases that trap heat in the atmosphere are referred to as greenhouse gasses (GHGs) because they
capture heat radiated from the earth that would otherwise be lost to space. While the physical
mechanism of this heat capture is different than for a greenhouse, it has the same effect of keeping
surface temperatures warmer, and so these gases are referred to as GHGs. The accumulation of GHGs
contributes to temperature increases and global climate change. Regulated GHGs include CO2, methane
(CH4), nitrous oxide (N2O), sulfur hexafluoride (SF6), perfluorocarbons (PFCs), and hydrofluorocarbons
(HFCs). Carbon dioxide, methane, and nitrous oxide are commonly emitted from sources of fuel
combustion (e.g., stationary boilers, heaters, engines, and mobile sources such as construction
equipment and on -road vehicles). Methane is also commonly emitted from agricultural practices such as
livestock and crop farming. PFCs and HFCs can be found contained within industrial processes, electrical
equipment, and building cooling systems as coolants/refrigerants, although sometimes these systems
leak into the atmosphere. GHGs have long atmospheric lifetimes that vary from one year to thousands
of years and have significantly varying potentials to trap heat that are described as their global warming
potential. According to EPA's GHG emission factors hub, on a 100-year time horizon, CH4 is estimated to
be 28 times as potent as CO2 at trapping heat, N2O is estimated to be 265 times as potent as CO2, while
SF6 is 23,500 times more potent than CO2. GHG emissions are typically reported as CO2 equivalents (CO2-
e), which convert the quantities of non-0O2 emissions into an equivalent amount of CO2 to report
emissions as a single quantity, usually in metric tons.'
In 2021, the state of Washington produced approximately 96 million gross metric tons of CO2-e. The
transportation industry is the largest source, at 40 percent of the state's GHG emissions, followed by
industrial, residential, and commercial energy use at 19, 6, and 5 percent, respectively, and electricity
consumption (both in state and out of state) at 19 percent. The sources of the remaining 10 percent of
emissions are agriculture and waste management processes (Ecology 2021a).
Some of the effects of climate change over the last 50 to 100+ years in Washington State include the
following, as presented in a special report issued by the Intergovernmental Panel on Climate Change (PSI
2021):
• Average snowpack has declined by approximately 30 percent from 1955 to 2016.
• The total area occupied by glaciers in the North Cascades has declined by more than 56 percent
since 1900.
• Sea level has risen in northern Puget Sound by as much as four inches, with other increases
elsewhere.
' Criteria pollutants and toxic pollutants are typically reported in units of short tons (English units).
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• Peak stream flow is occurring earlier in the year by as much as 20 days when comparing 1948
data to 2002 data for the most snow-covered areas near Puget Sound.
• Coastal waters have warmed between 0.9°F and 1.8°F between 1990 and 2012, with the Pacific
Ocean and Puget Sound shifting to slightly less alkaline conditions.
4.5.2 Relevant Plans, Policies, and Regulations
The relevant federal, state, and local laws, regulations, Executive Orders, plans, and policies that
establish the regulatory framework regarding air quality and greenhouse gases (GHGs) are provided
below in Table 4.5-1.
Table 4.5-.1 Summary of Relevant Air Quality and GHQ Laws Regulations, Plans, and Policies
Lanus, Regulations, Plans, and Policies
Description
Federal Level
Clean Air Act and Amendments
(https://www.epa.gov/clean-air-act-
Enacted in 1970, as amended in 1977 and 1990, requires
the USEPA to develop and enforce regulations to protect
the public from air pollutants and their health impacts.
overview/evolution-clean-air-act)
National Ambient Air Quality Standards (NAAQS)
(https://www.epa.gov/criteria-air-
Established by USEPA. Specifies the maximum acceptable
ambient air concentrations for seven criteria air
pollutants: carbon monoxide (CO), ozone, nitrogen
dioxide (NO2), sulfur dioxide (SO2), lead, and particulate
matter (PM2.5 and PM10)• Primary NAAQS set limits to
protect public health, and secondary NAAQS set limits to
protect public welfare. Geographic areas where
concentrations of a given criteria pollutant violate the
NAAQS are classified as nonattainment areas for that
pollutant; maintenance areas have reduced pollution to
achieve standards but have long-term requirements to
ensure that they maintain attainment.
pollutants/naafis-table)
Transportation Conformity (40 Code of Federal
Regulations [CFR] 93, Subpart A)
https://www.epa.gov/state-and-local-
transportation/project-level-conformity-and-hot-
spot -analyses
Required under the Clean Air Act, transportation
conformity ensures that federally supported highway and
transit projects are consistent with a state's air quality
goals. It applies to areas that do not meet or previously
did not meet the NAAQS for ozone, carbon monoxide, or
particulate matter. Conformity determinations are
required for transportation plans, programs, and projects
to ensure they do not worsen air quality.
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Lanus, Regulations, Plans, and Policies
Description
Updated Interim Guidance on Mobile Source Air
Toxic (MSAT) Analysis in National Environmental
Policy Act (NEPA) Documents
https://www.fhwa.dot.gov/ENVIRONMENT/
USEPA identified nine compounds with significant
contributions from mobile sources that are among the
national and regional -scale cancer risk drivers or
contributors and non -cancer hazard contributors from the
2011 National Air Toxics Assessment. These are 1,3-
butadiene, acetaldehyde, acrolein, benzene, diesel
particulate matter, ethylbenzene, formaldehyde,
naphthalene, and polycyclic organic matter.
FHWA established the framework to evaluate MSAT
impacts in NEPA documents using a tiered approach: (1)
No analysis for projects with no meaningful MSAT effects,
such as categorical exclusions; (2) Qualitative analysis for
projects with low potential effects, like minor widenings
or new interchanges with AADT below 140,000-150,000;
and (3) Quantitative analysis for projects with higher
potential effects, such as major freight facilities or
highways exceeding 140,000-150,000 AADT. For
applicable projects, all nine priority MSATs are
considered, and mitigation strategies are explored if
emissions differences among alternatives are significant.
air quality/air toxics/policy and guidance/msat/
GHG Reporting Program Rule (40 CFR 98)
The GHG Reporting Program requires reporting of GHG
data and other relevant information from large GHG
stationary emission sources, fuel and industrial gas
suppliers, and CO2 injection sites in the United States. The
numeric reporting threshold is 25,000 metric tons per
year of GHGs in terms of CO2 equivalent emissions.
GHG Emissions and Fuel Efficiency Standards for
Medium- and Heavy -Duty Engines and Vehicles
(numerous parts under 40 CFR and 49 CFR)
The USEPA and the Department of Transportation's
National Highway Traffic Safety Administration jointly
finalized standards for medium- and heavy-duty vehicles
that would improve fuel efficiency and cut carbon
pollution to reduce the impacts of climate change.
State Level
Washington State General Regulations for Air
Pollution Sources (WAC 173-400); Washington
State Clean Air Act (RCW 70.94)
Establishes the rules and procedures to control or prevent
the emissions of air pollutants; provides the regulatory
authority to control emissions from stationary sources,
reporting requirements, emissions standards, permitting
programs, and the control of air toxic emissions.
Washington State Department of Transportation
(WSDOT) Air Quality and Greenhouse Gas
Guidance
(https://wsdot.wa.gov/engineering-
Outlines requirements for evaluating air quality, MSATs,
GHG emissions, and energy impacts in WSDOT projects.
Ensures compliance with NEPA, SEPA, and federal and
state conformity regulations. Provides a tiered analysis
framework, decision trees, and mitigation strategies for
transportation projects, including the use of MOVES and
ICE for emissions inventory modeling.
standards/environmental-guidance/air-quality-
energy -greenhouse -gas -emissions)
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Lanus, Regulations, Plans, and Policies
Description
Washington State Ambient Air Quality Standards
(WAC 173-476)
Establishes maximum acceptable levels in the ambient air
for particulate matter, lead, SO2, NO2, ozone, and CO;
Washington adopts current federal NAAQS in state
regulations.
Washington State Greenhouse Gas Reporting
Regulation (WAC 173-441)
Requires specific emissions source categories or other
facilities to annually report their greenhouse gas
emissions; 10,000 metric tons per year is the numeric
threshold.
Washington State Controls for New Sources of
Toxic Air Pollutants (WAC 173-460)
Establishes controls for new and modified sources of toxic
air pollutants.
Limiting Greenhouse Gas Emissions (RCW 70.235)
Requires state to reduce overall GHG emissions as
compared to a 1990 baseline and to report emissions to
the governor biannually.
Local Level
Puget Sound Clean Air Agency Regulations
(Regulations I through III, activated by RCW
70.94)
Regulate stationary sources of air pollution in Pierce, King,
Snohomish, and Kitsap counties. Include emissions
standards and permitting, evaluating toxic air
contaminant impacts, and SEPA requirements.
King County Comprehensive Plan
The King County Comprehensive Plan (King County 2024g)
outlines strategies and policies for environmental
protection,
conservation, restoration, and sustainability, which
include improving air quality and reducing greenhouse gas
emissions with reduction goals for 2020 through 2050,
and preparing for climate change effects.
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l aws, Regulations, Plans, and Policies
Description
City of Tukwila Comprehensive Plan
The City of Tukwila Comprehensive Plan 2024 Update
(City 2024e) outlines strategies and policies for protecting
clean air and the climate for present and future
generations through reduction of greenhouse gas
emissions and promotion of efficient and effective
solutions for transportation, clean industries, and
development. Policies/goals with direct impact to this
project include:
Policy T-1.4 . Work with BNSF to mitigate impacts
associated with rail and intermodal yard operations within
Tukwila's residential neighborhoods.
Goal T-5: Environment - Plan, design, and construct
transportation projects that reduce greenhouse gas
emissions, improve community health, and protect the
natural environment.
Policy T-5.1. Collaborate with King County, the Port of
Seattle, and BNSF to ensure that King County
International Airport, SeaTac International Airport, and
BNSF railway operations and development:
• Enhance Tukwila goals and policies;
• Incorporate Tukwila land use plans and
regulation;
• Minimize adverse impacts to Tukwila residents;
and,
• Are not encroached upon by incompatible land
uses.
Sources: www.epa.gov; Rulemaking - Washington State Department of Ecology, King County 2024g, City 2024a
4.5.2.1 Descriptions of Federal, State, and Local Standards
The 1970 Federal Clean Air Act and subsequent amendments required the EPA to establish regulations
for controlling the nations' air quality. These regulations set criteria for the National Ambient Air Quality
Standards (NAAQS). The primary NAAQS are protective of public health. The secondary NAAQS are
protective of public welfare and the environment. Both primary and secondary standards specify
ambient air concentration limits, with a safety margin, for pollutants to avoid adverse health and
environmental effects. These standards are designed to protect the most susceptible public populations
such as those with respiratory illnesses, the very young, the elderly, and those engaging in strenuous
work or exercise.
The EPA identified seven pervasive criteria air pollutants and established health -based ambient air
quality standards for them. Ozone (03), carbon monoxide (CO), particulate matter (PM), nitrogen
dioxide (NO2), sulfur dioxide (SO2), and lead (Pb) were the initial criteria pollutants followed by PM10
(particulate matter less than or equal to 10 microns in diameter) and PM2.5 (particulate matter less than
or equal to 2.5 microns in diameter), which are subsets of particulate matter and more commonly
regulated. Ozone is a pollutant that is not typically directly emitted, but it forms in the lower
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atmosphere from direct emissions of NOx and volatile organic compounds (VOC) and their
photochemical reactions with sunlight.
Geographic areas of the United States that do not meet the NAAQS for any one or more of the criteria
pollutants are designated by the USEPA as nonattainment areas. Areas that were once designated
nonattainment but are now achieving the NAAQS are termed maintenance areas. Areas that have
pollutant levels below the NAAQS are termed attainment areas. In nonattainment areas, states must
develop plans to reduce emissions and bring the area back into attainment with NAAQS. Maintenance
areas have requirements that last for at least 20 years to ensure that they stay in attainment. The
Allentown proposed Project is in King County, Washington, which is classified as in attainment with the
NAAQS for all criteria pollutants.
As of May 14, 2021, King County went from maintenance status to attainment status for PM10 as the 20-
year maintenance period lapsed on that date. As of October 11, 2016, and November 25, 2016, King
County went from maintenance status to attainment status for CO and one -hour Ozone as the 20-year
maintenance period lapsed on those dates, respectively (EPA 2025a). As such, there will be no
requirement for quantitative CO or PM hot -spot analysis for transportation conformity purposes for this
project. The Metropolitan Planning Organization (MPO), Puget Sound Regional Council (PSRC), is
responsible for demonstrating the regional conformity via long-range transportation plans (LRTPs)
and/or Transportation Improvement Programs (TIPs) by showing that projected emissions remain within
the State Implementation Plan (SIP) motor vehicle emissions budgets (MVEBs). Project -level hot -spot
analysis is not required for ozone, but non-exempt projects must be included in a conforming TIP and
LRTP. Conformity must be redetermined at least every four years or when significant changes occur,
with interagency consultation involving USEPA, FHWA, Federal Transportation Administration (FTA),
state air agencies, and MPOs.
Table 4.5-2 identifies the primary and secondary NAAQS for the criteria pollutants under federal and
Washington State law. Washington has adopted the federal primary and secondary standards.
Table 4.5-2 Federal and State Ambient Air Quality Standards
Pollutant
Averaging
Time
Primary Standard
Secondary Standards
Form
Ozone
8 hours
0.070 ppm'
0.070 ppm
Annual 4th-highest
daily max. 8-hour
concentration,
averaged over 3 years
Carbon
monoxide
(CO)
1 hour
35 ppm
No applicable standard
Not to be exceeded
more than once/year
8 hours
9 ppm
No applicable standard
Nitrogen
dioxide (NO2)
1 hour
0.100 ppm (100 ppb)
No applicable standard
98th percentile of 1-
hour daily maximum
concentrations,
averaged over 3 years
Annually
0.053 ppm (53 ppb)
0.053 ppm (53 ppb)
Annual mean
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Pollutant
Averaging
Time
Primary Standard
Secondary Standards
Form
Sulfur dioxide
(S02)
1 hour
0.075 ppm
No applicable standard
99th percentile of 1-
hour daily maximum
concentrations,
averaged over 3 years
3 hours
0.5 ppm for state, no
applicable standard for
federal
0.5 ppm
Not to be exceeded
more than once/year
Annually
0.02 ppm for state, no
applicable standard for
federal
No applicable standard
Not to be exceeded
24 hours
0.14 ppm for state, no
applicable standard for
federal b
No applicable standard
Not to be exceeded
more than once/year
Particulate
matter
(PM10)
24 hours
150 µg/m3c
150 µg/m3
Not to be exceeded
more than once/year
on average over 3 years
Fine
particulate
matter
(PM2.5)
24 hours
35 µg/mad
35 µg/m3
98th percentile,
averaged over 3 years
Annually
9 µg/m3e
15 µg/m3
Annual mean, averaged
over 3 years
Lead
Rolling 3-
month
average
0.15 µg/m3
0.15 µg/m3
Not to be exceeded
Sources: EPA 2025b; WAC Chapter 173-476
a This 2015 NAAQS is the most stringent NAAQS still in effect for ozone. A 2008 8-hour ozone standard of 0.075 ppm also
remains in effect. The 2015 8-hour ozone standard is attained when the 3-year average of the fourth highest daily
concentration is 0.070 ppm or less.
b The 24-hour average concentration for sulfur oxides in the ambient air must not exceed 0.14 ppm by volume more than once
per calendar year (WAC 173-476-130).
c The 24-hour PM10 standard is attained when the 3-year average of the 99th percentile of monitored concentrations is less
than the standard.
d The 24-hour PM2.5 standard is attained when the 3-year average of the 98th percentile is less than the standard.
Note: ppm: parts per million; µg/m3: micrograms per cubic meter.
e On March 6, 2024, the USEPA promulgated a final rule that changed this standard to 9 ug/m3 effective on May 5, 2024. While
there may be activity in 2025 by the Trump Administration to attempt to revert back to the previous 12 µg/m3 standard, that
would require legal court decisions and regulatory changes that have not been reached and completed at this time.
The USEPA General Conformity Rule (40 Code of Federal Regulations [CFR] 51 and 93, Subpart B) applies
to federal actions or federally funded actions (non -transportation agency actions) occurring in
nonattainment or maintenance areas when the total direct and indirect emissions of nonattainment
pollutants (or their precursors) exceed specified thresholds. The emissions thresholds that trigger
requirements for a conformity analysis are called de minimis levels. De minimis levels (in tons per year
[tpy]) vary by pollutant and depend on the severity of the nonattainment status for the air quality
management area in question. These de minimis levels represent the quantity of emissions above which
the need for a conformity assessment with the State Implementation Plan (SIP) is required. The SIP is
the state's plan for meeting and maintaining the NAAQS, which must be approved by the USEPA,
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including revisions. The USEPA General Conformity rule does not apply in King County; therefore, it
doesn't apply to the Allentown proposed Project.
The USEPA Transportation Conformity Rule (40 CFR 93, Subpart A) applies to federal actions or federally
funded actions (transportation agency actions) occurring in nonattainment or maintenance areas. King
County is not part of a nonattainment or maintenance area. However, PSRC, which is the MPO
responsible for demonstrating regional conformity in the area that includes King County, is still issuing a
TIP due to the maintenance status of Pierce County. Therefore, transportation conformity
demonstration is still in place for projects inside King County. The project must also follow WSDOT
guidance for compliance with the Regional Transportation Improvement Plan, which is discussed further
below in Section 4.5.3.1 Impacts Methodology.
The Clean Air Act identifies 187 compounds that are known to cause cancer or serious health effects.
This group of compounds is called air toxics or hazardous air pollutants (HAPs). The USEPA has identified
21 HAPs emitted from mobile sources, referred to as MSAT, within a few final rules: Control of Emissions
of Hazardous Air Pollutants from Mobile Sources (40 CFR 80, 85, 86). These rules mainly regulate fuel
and vehicle manufacturers. The USEPA designated nine priority MSAT due to their potential for causing
cancer and serious health effects when exposures are long enough and at sufficient concentrations:
acetaldehyde, acrolein, benzene, ethylbenzene, formaldehyde, diesel particulate matter (DPM)/diesel
exhaust organic gases, naphthalene, polycyclic organic matter, and 1,3-butadiene. These priority MSAT
are to be analyzed in this EIS regarding operational emissions from truck hauling to and from the BNSF
South Seattle Intermodal Facility. Per WSDOT and FHWA's MSAT guidance, this project would be
changing the traffic pattern near the major intermodal freight facility which has the potential to
concentrate high levels of diesel particulate matter in a single location. Additionally, the guidance
indicates a project involving a significant number of diesel vehicles as a new project or accommodating
with a significant increase in the number of diesel vehicles for an expansion project near populated area,
is considered a Project with Higher Potential MSAT Effects per FHWA guidelines. A quantitative MSAT
analysis is required for this type of project.
The Washington State Department of Ecology (Ecology) provides protection of public health and the
environment by establishing and enforcing rules to prevent and reduce air pollution and approve
emissions with limitations. Enforcement of most of the Clean Air Act requirements has been delegated
by the USEPA to Ecology and seven clean air agencies with local authority in the state. Ecology works to
improve air quality throughout the state by overseeing the development and conformity of the SIP.
Ecology oversees the statewide air monitoring network and ensures that the monitoring data meets the
federal requirements of 40 CFR 58. Ecology also requires facilities that have applicable emissions source
categories (e.g., stationary fuel combustion, electricity generation, specific types of manufacturers,
petroleum industry sources) and emit at least 10,000 metric tons of CO2 equivalents annually to report
their greenhouse gas emissions annually (WAC Chapter 173-441).
The Puget Sound Clean Air Agency (PSCAA) regulates air quality within the counties of Pierce, King,
Snohomish, and Kitsap. PSCAA has local authority for setting regulations and permitting of stationary
emissions sources and construction emissions.
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4.5.3 Methodology
This EIS is providing only a qualitative analysis for air quality, MSAT, and GHG emissions. The qualitative
analysis for operational activities indicates a potential for air quality and GHG impacts; however, after a
preferred alternative is chosen and a full traffic study/analysis is completed, it will support a quantitative
analysis of operational activities to confirm expected air quality, GHG and climate change impacts. In a
similar manner, construction activity impacts are only provided qualitatively. The evaluation of potential
impacts on air quality and GHG from a quantitative analysis will consist of conducting the following
tasks:
• Select the appropriate study area for the travel demand model that includes the baseline and
horizon year for both the no action condition and the preferred alternative.
• Develop the travel demand model for the no action condition and the preferred alternative,
once selected over the design year. The study will assess heavy vehicle traffic within the
designated roadway network, including truck movements entering and exiting the BNSF
Intermodal Facility and routes to/from the nearest highway.
• Using the results of the full traffic study/analysis, develop a quantitative assessment of the
levels of direct and indirect criteria pollutants, MSAT, and GHG emissions from the Project
operational activities for the no action condition and the preferred alternative.
• Within the study area, select the appropriate roadway links that would experience ±5% AADT
between the no action condition and the preferred alternative in the baseline year and/or
horizon year.
• The county level MOVES analysis will be based on the results of the travel demand model that
include vehicle classification, road type VMT distribution, fuel mix, alternative vehicle fuel type,
speed distribution, and vehicle population data along with traffic route information and county
level information to generate emission factors (in g/VMT) in the USEPA MOVES5 model .The
criteria air pollutant, MSAT and GHG emission factors will be multiplied by the network vehicle
miles traveled for heavy vehicle traffic under the No Action condition and the Preferred
Alternative to calculate the annual emissions burden.
• For the construction activity quantitative GHG analysis, refer to the FHWA Infrastructure Carbon
Estimator Tool (ICE) that will be used to estimate energy related GHG emissions based on
general construction characteristics in accordance with the WSDOT Air Quality and GHG
Emissions Guidance. Criteria pollutant emissions estimation is not required because the project
is not located in a nonattainment or maintenance area.
4.5.3 1 1 Characterization of Air Quality Impacts
The proposed Project is located in an area designated as attainment for all criteria air pollutants under
the NAAQS. Given the attainment status and the lapsed of maintenance period for all criteria air
pollutants, this project does not require a quantitative hot -spot analysis for CO or PM under
transportation conformity regulations per WSDOT Air Quality and Greenhouse Gas Guidance. As a
result, the proposed project is not anticipated to contribute to or exacerbate any violations of the
NAAQS, and no significant impacts to criteria air pollutants are expected. However, to be consistent with
transportation conformity, the emissions induced by this project will need to be reflected in the Puget
Sound Regional Council latest Regional Transportation Improvement Plan.
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4.5.3.1..2. Characterization of MSAT Dmpacts
The project site is located in the Allentown district of Tukwila, Washington, near major transportation
corridors, including 1-5, SR 599, and the BNSF South Seattle Intermodal Facility, which contribute to
elevated emissions of diesel particulate matter (DPM) and other MSAT. The proximity of residential
areas, schools, parks, and natural habitats to the project site increases the potential for human exposure
to air toxics.
Per FHWA and WSDOT MSAT guidance, this project involves changes in traffic patterns near a major
intermodal freight facility and has the potential to concentrate high levels of DPM due to the significant
presence of diesel vehicles. Given the project's characteristics and its location near a populated area, it
qualifies as a Project with Higher Potential MSAT Effects. The quantitative MSAT analysis to assess
operational emissions will be conducted when the preferred alternative is chosen.
4.5.3.1..3 Characterization of GHG Dmpacts
GHG emissions from transportation projects are typically assessed using the MOVES model for
operational emissions estimate and the FHWA Infrastructure Carbon Estimator (ICE) tool for
construction -related emissions, as recommended in the WSDOT Air Quality, Greenhouse Gas, and
Energy Guidance (WSDOT 2024b).
At the time of this EIS draft, no preferred alternative has been selected. As a result, the travel demand
model required to quantify project -specific vehicle miles traveled (VMT), speed distribution, and other
key inputs for the MOVES -based GHG analysis is not yet available. WSDOT guidance indicates that a
quantitative GHG analysis should be conducted using the MOVES modeling. Given the absence of
essential traffic data, a quantitative GHG emissions analysis could not be performed at this time.
Once the preferred alternative is identified, the analysis should incorporate the latest planning
assumptions, methodologies consistent with WSDOT and federal guidance, and an evaluation of both
operational and construction -phase emissions. Per WSDOT guidance, the MOVES model should be used
to estimate tailpipe emissions, while the ICE tool should be applied to estimate emissions from material
production, construction equipment, and worksite activities.
4.5.4 Impacts Analysis
4.5.4 1 1 Construction Dmpacts
Construction activities generating air pollutant emissions include fuel combustion within the internal
combustion engines of non -road construction equipment. This could include graders, bulldozers,
backhoes, loaders, skid steers, excavators, rollers, cranes, high lifts, dump trucks, concrete trucks, paving
equipment, street sweepers, and water trucks. In addition, particulate fugitive dust emissions would be
generated from land clearing disturbances and soil excavations and movements, and passenger and
truck delivery traffic on unpaved and paved roads. Asphalt paving of roads and parking areas would
generate minor VOC emissions. The construction workers commuting in vehicles would also generate
some combustion emissions; however, based on the size of the construction and low level of workers
for any alternative, those commuting emissions would be minimal. As stated previously, construction
activity GHG impacts will be further analyzed quantitatively when the construction energy analysis is
completed using the ICE model.
Construction activities will operate in compliance with PSCAA Regulation I, Section 9.15 — Fugitive Dust
Control Measures, which include minimizing fugitive dust through control methods such as wet or
192
chemical suppression techniques, reducing vehicle speeds, cleaning vehicle undercarriages or wheels,
and covering or wetting truckloads of soils or loose materials. The construction activities will also comply
with PSCAA Regulation I, Section 9.03 — Emission of Air Contaminant: Visual Standard, which includes a
20 percent opacity standard.
The following BMPs would be implemented during construction to minimize potential for air quality
impacts during construction in accordance with King County Comprehensive Plan development policies
and goals, and Puget Sound Clean Air Agency Regulation 1, Section 9.15:
• Apply dust suppression materials on exposed soil areas and construction paths/roadways and/or
water during dust -generating construction activities to limit fugitive dust emissions.
• Require mobile construction equipment and any stationary engines be powered by USEPA-
certified engines that meet applicable USEPA emission standards.
• Implement and enforce a 10- to 15-mile-per-hour speed limit for construction vehicles while
moving on site.
• Provide a wheel washing and/or vehicle undercarriage cleaning system for trucks leaving the
Project construction site.
• Require all loose material truck loads to have covers and/or use wetting agents to minimize
escape of dust.
4.5.4.1..2. Operations Dmpacts
The qualitative analysis for operational activities indicates a potential for adverse air quality and GHG
impacts, including MSAT impacts; however, after a preferred alternative is chosen and a full traffic
study/analysis is completed, it will support a quantitative analysis of operational activities to determine
the expected air quality, GHG and climate change impacts.
4.5.5 Mitigation Measures
The determination of whether a significant air quality or GHG impact from Project operations emissions
is expected has not been made at this time; therefore, the need for mitigation measures is also not
determined at this time. After a full traffic study/analysis is completed and a quantitative air quality and
GHG analysis is completed, that determination will be made and documented. Implementation of
fugitive dust best management practices described above under Construction Impacts would minimize
construction activity emissions.
4.5.6 Significant Unavoidable Adverse Impacts
The determination of whether a significant air quality or GHG impact from Project operations emissions
is expected has not been made at this time; therefore, this section will not be completed until after a
preferred alternative is chosen, a full traffic study/analysis is completed, and a quantitative air quality
and GHG analysis is completed.
193
4.6 Transportation
This section provides an analysis of potential impacts of truck routes on the existing transportation
network.
4.6.1 Affected Environment
The study area encompasses routes with key roadways and intersections that connects the local
freeway network to the BNSF facility. The proposed alternatives in this study (No Action Alternative,
Alternative 2, Alternative 3B, and Alternative 4) are reconfigurations of the existing BNSF yard, which
would also modify the existing truck routes currently used by trucks to travel to the facility.
The study area includes a few different routes:
• The existing truck route without detour* ("No Action Alternative").
o *An existing temporary detour route is being used due to structural damage to the 42nd
Avenue South bridge. The detour route was excluded from this EIS analysis. Freeways
were also excluded from the EIS analysis.
• Three truck routes associated with proposed Alternatives 2, 3B, and 4.
Six study intersections from the traffic study conducted for this project are identified as critical
connections between the local road network, regional freeways, and the BNSF facility. These
intersections overlap with truck routes that serve the existing BNSF facility (temporary detour route)
and the proposed alternative truck routes which includes the No Action Alternative, Alternative 2,
Alternative 3B, and Alternative 4.
All analyses in this transportation section are presented by study intersections instead of truck routes to
be consistent with the traffic study conducted for the project, except pavement conditions data.
Pavement conditions data is provided by the City of Tukwila (City) and analyzed by roadways that
overlap with truck routes instead of study intersections.
The list of six2 study intersections and their identifiers are as follows and shown in Figure 4.6-1. These
identifiers are not associated with a particular order:
• Intersection 1: Southbound (SB) I-5 off -ramp & South Boeing Access Road
• Intersection 2: Interurban Avenue South & Gateway Drive (N)
• Intersection 3: Interurban Avenue South & Gateway Drive (S)/South 133rd Street
• Intersection 4: Interurban Avenue South & SB I-5 off -ramp
• Intersection 5: Interurban Avenue South & Northbound (NB) I-5 on -ramp
• Intersection 6: Martin Luther King Jr Way South & South 129th Street
Table 4.6-1 lists the alternatives and the corresponding study intersections along the truck routes, as
presented in the traffic study completed for this project. A figure of the alternatives, alternatives truck
routes and intersections are shown in Figure 4.6-1.
2 E Marginal Way South & South 115th Street was included in the Allentown EIS Intersection Study (Appendix D),
but will not be included in this analysis because it does not overlap with any of the project's alternatives.
194
Table 4.6-1 Project Alternatives and Associated Intersections
Alternatives
Associated Intersections
No Action Alternative
Interurban Ave S & Gateway Dr (N)
Interurban Ave S & Gateway Dr (S)/S 133rd St
Interurban Ave S & SB I-5 off -ramp
Interurban Ave S & NB I-5 on -ramp
Alternative 2
SB I-5 off -ramp & S Boeing Access Rd
Alternative 3B
Interurban Ave S & Gateway Dr (S)/S 133rd St
Interurban Ave S & SB I-5 off -ramp
Interurban Ave S & NB I-5 on -ramp
Alternative 4
Martin Luther King Jr Way S & S 129th St.*
*Note: Martin Luther King Jr Way S & S 129th St is the closest intersection to Alternative 4 that had data available.
195
- tlanerneanGerra
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artin Luther King Jr Way S &
S 129th St
bP '
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Figure 4.6-1 Study Intersections and Alternative Footprints
196
t",.I"FY ()F TUKWILA
ikLLEIN TOWN IE IS
TRANSPORTATION
OverOew
• Anatazed
Irdossetaion
General Project
Alt ernatilve Study Areas
Ataternative 2
'-"'"' Footprint
arat Allornattes 3B
erenG Fe one ri ni
No Actium Truett
Routes
. . •
Seattle
Bellevue.
' 1
I
Renton
1"
Kent
1 000 Feet
4.6.2 Relevant Plans Policies and Regulations
Relevant policies and regulations related to transportation are summarized in Table 4.6-2.
Table 4.6-2 Regulations and Policies for Transportation
Laws and Regulations
Description
Federal
Highway Safety Act and the Federal Railroad
Safety Act
Gives the Federal Highway Administration (FHWA) and
Federal Railroad Administration (FRA) regulatory
jurisdiction over safety at federal highway/rail grade
crossings.
Manual on Uniform Traffic Control Devices
(23 U.S.C. 109(d))
Provides standards and guidelines for traffic control
devices.
State
Transportation System Policy Goals (RCW
47.04.280)
Establishes the following goals for the transportation
system in Washington State: economic vitality,
preservation, safety, mobility, environment, and
stewardship.
Motor Vehicles — Rules of the Road (RCW
46.61)
Establishes rules of the road for vehicle and rail
crossings.
City Streets as Part of State Highways (RCW
47.24)
Regulates the maintenance and jurisdictional control
for city streets that are part of state highways.
Local
Traffic Regulations (Tukwila Municipal Code
Title 9)
Establishes regulations for vehicle traffic in the City of
Tukwila.
City of Tukwila Comprehensive Plan —
Transportation Element
The Transportation Element (Element 13) of the
Tukwila Comprehensive Plan establishes Tukwila's
transportation goals and policies for the 20-year
planning period.
City of Tukwila Infrastructure Design and
Construction Standards
Establishes design and construction requirements,
criteria, and specifications for construction projects in
the City of Tukwila.
4.6.3 Methodology
The Allentown EIS Intersection Study (Appendix D) conducted for this project involved the collection and
analysis of various transportation variables at six study intersections: turning movement counts (TMCs),
level of service (LOS) and delay, Annual Average Daily Traffic (AADT), and crash data. Pavement
conditions data for roadways were provided from the City. Results from the traffic analysis would drive
the impacts analysis in Section 4.6.4.
4.6.3.1 LOS and Delay
Vehicle turning movement count (TMC) data was collected to produce the LOS and Delay measures.
TMCs provide insights into traffic volumes, peak hour flows, and directional distributions among
197
motorized vehicles, heavy vehicles, and pedestrians/bicycles. TMC data was collected on April 23, 2024,
during the PM Peak hours from 4:00 PM to 6:00 PM, by All Traffic Data Services, and consists of truck
turns and passenger vehicle turns. Video camera counts were used instead of tube counts at these
intersections, as cameras are easier to install and are more effective in capturing traffic counts for
different movements. TMC data for four intersections along the Interurban Ave South were balanced3,
as these intersections are adjacent to each other. Google Earth was used to collect geometric data of
the seven intersections to ensure the accurate representation of existing lane configurations.
The quantitative data analysis of traffic operations at the intersections for the Project was conducted
using Synchro 11. Synchro 11 is a traffic analysis tool that assists engineers and planners in designing,
modeling, optimizing, and simulating intersection networks. This software was used to calculate LOS and
delay at all the intersections identified in Section 4.6.1. LOS and delay measures provide insight into the
quality of traffic at the intersections. The average of the delays experienced by all vehicles at each
intersection (due to red lights, stop signs, or other control features) are determined, and each of these
average delays are assigned a letter grade referred to as LOS, ranging from LOS A (least congested) to
LOS F (worst congested).
The grading scale for LOS is based on the guidelines from the 6th edition of the Highway Capacity
Manual (HCM) (Cubic Trafficware 2019; Transportation Research Board (TRB) (TRB 2016). The HCM is a
transportation manual widely accepted and used by the U.S. Department of Transportation (USDOT) and
Federal Highway Administration (FHWA). Table 4.6-3 shows the HCM peak hour delay performance
indicators for signalized and unsignalized intersections.
Table 4.6-.3 Delay Performance Indicators for Intersection LOS
LOS
Description
A No congestion; nearly all drivers experience little to no delay
Average Delay Range
(seconds/vehicle)
Signalized Unsignalized
0 to 10.0 0 to 10.0
B No congestion; most drivers experience little to no delay
10.1 to 20.0 10.1 to 15.0
C Light congestion; most drivers experience minor delay
20.1 to 35.0 15.1 to 25.0
D Moderate congestion; individual movements with high delay
35.1 to 55.0 25.1 to 35.0
E Heavy congestion, with high delays on multiple movements
55.1 to 80.0 35.1 to 50.0
Extensive delays due to cycle failures at signals or sparse
opportunities to make desired movements at unsignalized
intersections
Source: TRB 2016; Cubic Trafficware 2019.
80.1 or more 50.1 or
more
The HCM delay performance indicators are used to assign LOS to the Synchro delay results, and the
methodology for measuring intersection vehicle delays in the Synchro 11 model is the same as
methodology used in the 6th edition of the HCM.
Generally, LOS D is considered to have moderate congestion but is considered the worst acceptable
condition for peak hour intersection traffic operations. LOS E is often characterized by having heavy
3 "Balance" in traffic analyses refers to the process of distributing traffic volumes equally across intersections.
Balancing ensures accuracy, consistency, reduces errors and ensures an efficient allocation of data.
198
congested conditions, with unstable flow and high delays. At LOS F, the intersection is overcapacity and
likely experiences congestion periods of 15 to 60 minutes per day.
According to the Transportation Element in the City of Tukwila Comprehensive Plan, the acceptable
Level of Service (LOS) standard is LOS E or better. Therefore, the City of Tukwila standard of acceptability
for intersection LOS (E or better) is applied for PM peak hour conditions in this project.
In addition to assessing existing conditions of LOS and delay in year 2024, future traffic conditions in
year 2045 were also projected. In accordance with traffic studies conducted by the City of Tukwila, an
annual growth rate of 1% was calculated to calculate traffic operations in the Synchro model for the year
2045. This analysis is critical for planning and implementing necessary improvements to accommodate
future traffic demand.
4.6.3.2 Vehicle Miles Traveled (VMT)
Vehicle Miles Traveled (VMT) was calculated using the Average Annual Daily Traffic (AADT) collected
from the Washington State Department of Transportation (WSDOT), and segment lengths measured
between the six intersections under study using Google Maps. Total VMT provides a metric for
evaluating traffic patterns and roadway usage in the area. Quantifying VMT offers insights into the
extent of vehicle travel across these segments, informing decisions on congestion management,
roadway maintenance needs, and potential environmental impacts, such as emissions and air quality.
The annual truck VMT would be used to analyze and compare between alternatives. Due to limited data
availability for these routes, some engineering judgment and assumptions were applied. For example,
AADT volume from related highways, such as 1-5 and SR 599, was used to estimate a more accurate
truck percentage for each route.
4.6.3.3 Crash Analysis
Crash data for six study intersections were requested for a five-year period, from January 1, 2019, to
December 31, 2023, through the WSDOT Public Disclosure Request Center. WSDOT crash data were
examined with respect to severity and year, both in terms of raw crash counts and, in the case of
intersections, the intersection crash rate. The intersection crash rate was calculated based on crash
records and estimated daily entering vehicle volumes.
4.6.3.4 Pavement Analysis
The project would increase truck traffic on public streets near the site; this is anticipated to have
impacts to existing pavement. To assess and compare the impact the increase truck traffic will have on
the roadway pavement, current PCI ratings, truck VMT and total pavement area was calculated for the
No Build and each Build alternative. Pavement conditions were analyzed to determine the potential
impact of trucks on remaining pavement service life. City of Tukwila Public Works Department has
updated data for the City's asphalt roadway inventory in 2024. This inventory includes existing
pavement conditions on city streets, and calculations of the Pavement Condition Index (PCI) ratings for
all roadways within the City.
To evaluate the existing pavement conditions within the study area, City streets that overlap with truck
routes for the alternatives were selected to provide PCI ratings. According to the City, PCI is a numerical
rating of the pavement condition based on the type and severity of distresses observed on the
pavement surface. The PCI value of the pavement condition is represented by a numerical index
199
between 0 and 100, where 0 is rated as "Very Poor" condition and 100 is rated as "Excellent" conditions.
Table 4.6-4 shows the ratings and associated descriptive terms outlined by the City below.
Table 4.6-4 Pavement Conditions and Associated Descriptive Terms
Pavement Condition
Index (PCI)
Descriptive Term
0 to 25
Very Poor
25 to 40
Poor
40 to 50
Marginal
50 to 60
Fair
60 to 70
Good
70 to 85
Very Good
85 to 100
Excellent
The square feet (sq. ft.) of roadway areas for each alternative would be reported to measure the
impacts of each alternative's truck route on existing pavement. If an alternative truck route impacts a
larger roadway surface area, this implies an increase in degradation of existing pavement, which
indicates that the pavement may require maintenance sooner. Degradation of existing pavements may
have implications on the City's operations and maintenance funding.
4.6.4 Impacts Analysis
The impacts analysis includes results from the transportation analyses and variables considered in
Section 4.6.3. Impacts are evaluated using the impact magnitude definitions listed in Table 4.6-5, and
comparisons are made between the proposed alternatives.
Table 4.6-•> Impact Magnitude and Description
Magnitude of Impact
Description
Little or No Impact
Proposed Project's truck routes would not adversely impact existing and future
projected roadway and intersection conditions.
Minor
There may be short-term or minor adverse impacts to existing and future
projected roadway and intersection conditions.
Moderate
There may be long-term or permanent adverse impacts to existing and future
projected roadway and intersections.
Significant
The proposed Project would cause long-term and adverse impacts to existing
and future projected roadways and intersections.
Similar routes are anticipated to be used during construction and operations. Hence, construction and
operations impacts are anticipated to be similar. For construction impacts, the study area consists of the
roads and intersections that construction vehicles would use to access the proposed Project site. For
operational impacts, the study area consists of roads and intersections used by trucks moving to and
from the BNSF facility to access the proposed alternative footprints (Figure 4.6-1).
4.6.4.1 LOS and Delay Results based on Turning Movement Counts (TMC)
As mentioned in Section 4.6.3.1, existing and future TMCs (2024 and 2045) at the intersections were
collected, and used to generate the LOS and delays standards at each intersection and their respective
200
directions. LOS and delay results by intersection would be used for the impact analysis in this EIS. Table
4.6-6 and Table 4.6-7 show the 2024 and 2045 LOS and delay results respectively, and Figure 4.6-2
shows the change between the 2024 and 2045 LOS and delay results. As mentioned in Table 4.6-3,
intersections with an LOS of A is generally the least congested, and intersections with an LOS of F is
generally the most congested.
201
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Study Intersections LOS/ Delay (s/veh)
Intersection 1: SB 1-5 off -ramp & S Boeing Access Rd
Intersection 2: Interurban Ave S & Gateway Dr (N)
Intersection 3: Interurban Ave S & Gateway Dr (S)/S 133rd St
Intersection 4: Interurban Ave S & SB 1-5 off -ramp
Intersection 5: Interurban Ave S & NB 1-5 on -ramp
Intersection 6: Martin Luther King Jr Way S & S 129th St
Q
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Intersection 1: SB 1-5 off -ramp & S Boeing Access Rd
Intersection 2: Interurban Ave S & Gateway Dr (N)
Intersection 3: Interurban Ave S & Gateway Dr (S)/S 133rd St
Intersection 4: Interurban Ave S & SB 1-5 off -ramp
Intersection 5: Interurban Ave S & NB 1-5 on -ramp
Intersection 6: Martin Luther King Jr Way S & S 129th St
v
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Figure 4.6-2 Change in LOS and Delay Results from 2024 to 2025 for Intersection .1 through 6
203
C I TY OFTUKW [ILA
AL ILENdkOWN EIS
"TRANSPORTATION
intersection
Levell Serviice (L0E0
Geserai Projed
Alternall ye Study Areas
C:731 Al tem allne 2 Footprint
Alternative 313
Idopyrrira
Alternative 4 Footarita
No Action Puck RouWAk
404, Balrectlonall
4Ada Skialtaddranal
Truck Routes Serviing
AJternafives
Alternative 2
11361.(eCti3Onal
tdpirarerainkkal
tdd 6,602065
860 Feet
4.6.4 1 1 No Action Alternative: Construction and Operations Impacts to LOS and Delay at Inter.sections
The No Action Alternative overlaps with four study intersections (Intersection 2, 3, 4, and 5).
Intersections overlapping with the No Action Alternative truck routes are anticipated to have a future
(2045) projected LOS and delay standard of B, which overall meets the City of Tukwila's standard of
acceptability for intersection LOS (E or better). Impacts are anticipated to range from little or no
impacts to minor impacts for the No Action Alternative.
4.6.4.1..2. Alternative 2.: Construction and Operations Impacts to LOS and Delay at Intersections
Alternative 2 overlaps with one study intersection (Intersection 1). Alternative 2 is anticipated to have
an existing (2024) or future (2045) projected LOS and delay standard of B, which meets the City of
Tukwila's standard of acceptability for intersection LOS (E or better). Impacts are anticipated to range
from little or no impacts to minor impacts for Alternative 2.
4.6.4.1..3 Alternative 3B: Construction and Operations Impacts to LOS and Delay at Intersections
Alternative 3B overlaps with three study intersections (Intersection 3, 4, and 5). Alternative 3B has an
existing (2024) or future (2045) projected LOS and delay standard of B, which meets the City of Tukwila's
standard of acceptability for intersection LOS (E or better). Impacts are anticipated to range from little
or no impacts to minor impacts for Alternative 3B.
4.6.4.1..4 Alternative 4 Construction and Operations Impacts to LOS and Delay at Intersections
Alternative 4 overlaps with one study intersection (Intersection 6). This intersection is outside of City of
Tukwila's jurisdiction. Alternative 4 is anticipated to have a future (2045) projected LOS and delay
standard of F, which is higher than King County's Level of Service standard of LOS E or better. Moderate
to significant impacts are anticipated from Alternative 4.
4.6.4.2 Vehicle Miles Traveled (VMT) Results
Truck VMT was calculated by multiplying the vehicle AADT, truck percentage, segment length for each
alternative, and total days in a year. Table 4.6-8 summarizes the annual truck VMT for each alternative.
All alternatives use different truck travel routes and have varying VMTs. A higher VMT could indicate
increased traffic congestion; increased collisions; result in greater vehicle emissions and adverse air
quality impacts; and signify an increase in roadway maintenance needs.
Table 4.6.8 Results of Annual Vehicle Miles Traveled (VMT) for Alternatives
Alternative Scenarios
Length (miles)
Site Truck AADT
(veh/day)
VMT (Annual)
Truck VMT for no action travel route
15.80
900
5,190,000
Truck VMT for travel route alternative 2
15.40
900
5,059,000
Truck VMT for travel route alternative 3B
11.10
900
3,646,000
Truck VMT for travel route alternative 4
26.40
900
8,672,000
As shown in Table 4.6-8, the highest annual VMT among the alternatives is 8.7 million; and the lowest
annual VMT is 3.6 million. Alternative 4 would have the highest annual VMT among the alternatives at
8.7 million, followed by the No Action Alternative and Alternative 2 at 5.2 and 5.1 million respectively.
Alternative 3B would have the lowest annual VMT at 3.6 million.
204
4.5.42.1 NoAction A|ternative: Annual VKXTResults
The No Action Alternative is anticipated to have an annual VIVIT of 5.2 million. In comparison with other
alternatives, this calculated VIVITisinthe middle range. The NoAction Alternative isanticipated to have
minor impacts to roadway conditions based on the calculated VMT.
4.5.422 Alternative 2: Annual VKXTResults
Alternative 2 is anticipated to have an annual VIVIT of 5.1 million. In comparison with other alternatives,
this calculated VIVIT is in the middle range. Alternative 2 is anticipated to have minor impacts to
roadway conditions based onthe calculated VMT
4.5.423 Alternative 313: Annual VMT Results
Alternative 3B is anticipated to have an annual VIVIT of 3.6 million. In comparison with other
alternatives, this calculated VIVITisinthe lowest range. Alternative ]B is anticipated to range from little
to no impacts to minor impacts to roadway conditions based on the calculated VMT.
4.5.42.4 Alternative 4: Annual VKXTResults
Alternative 4 is anticipated to have an annual VIVIT of 8.7 million. In comparison with other alternatives,
this calculated VIVIT is in the highest range. Alternative 4 is anticipated to range from minor to moderate
205
S Boein Access Road
AADT 33711
4 K-Factor: 10
GO
(,)
1
1A'' filN:PP '
rev a ralis hon
SB 1-5 off -ramp &
S Boeing Access Rd
AADT: 9860
K-Factor: 10
flifiriirN
f
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1-5 SB Off Ramp &
interurban Ave
AADT: 4935
K-Factor: 12
% Incralf aria gin
(Arc
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Martin Luther King Jr Way S &
BNSF S 129th St
intermodat
Rail Yard AADT: 25541
K-Factor: 10
40 lia
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ov
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1, ffau riff AADT: 5596 '0
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6 ° K-Factor: 9 ,
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Routes,
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°
Renton
Kent
Federal Way
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Date: 676/20
0 1.050 Feet
Figure 4.6-.3 Overview of Annual VMT by Alternatives
206
4.6.4..E Crash Analysis Results
Crash data for six study intersections was requested through the WSDOT Public Disclosure Request
Center. Data for 2019 to 2023 is shown in Table 4.6-9 and Table 4.6-10. The data shows a total of 138
crashes, with Martin Luther King Jr. Way South & 129th Street having the highest number of recorded
crashes. No fatalities were recorded in the data that was provided.
Table 4.6-9 Crash Data Summary 20.19..202.3 for Six Study Intersections
Intersection
2019
2020
2021
2022
2023
Total
SB I-5 off -ramp & S Boeing Access Rd
6
3
10
12
15
46
Interurban Ave S & Gateway Dr (N)
1
1
0
0
0
2
Interurban Ave S & Gateway Dr (S)/S
133rd St
1
2
5
4
3
15
Interurban Ave S & SB I-5 off -ramp
1
1
3
0
1
6
Interurban Ave S & NB I-5 on -ramp
1
1
0
1
4
7
Martin Luther King Way & S 129th St
13
15
13
12
9
62
Total by Year
25
24
31
31
33
138
Table 4.6-10 Crash Data Summary 20.19..202.:3for Six Study Intersections by Severity
Intersection
Fatal
Serious
Injury
Minor
Injury
Possible
Injury
No Injury
Total
SB I-5 off -ramp & S Boeing Access Rd
0
2
5
9
30
46
Interurban Ave S & Gateway Dr (N)
0
0
0
1
1
2
Interurban Ave S & Gateway Dr (S)/S
133rd St
0
0
7
0
8
15
Interurban Ave S & SB I-5 off -ramp
0
1
0
0
5
6
Interurban Ave S & NB I-5 on -ramp
0
0
3
0
4
7
Martin Luther King Way & S 129th St
0
0
7
17
38
62
Total by Severity
0
4
24
27
89
138
The intersection with the highest recorded total crashes is Martin Luther King Way & South 129th Street
at 62 total recorded crashes over the five-year period, which is the closest intersection to Alternative 4.
This intersection also has the highest number of severe crashes, with four crashes classified as "serious
injury" and 24 classified as "minor injury". The intersection with the lowest recorded total crashes is
Interurban Ave South/Gateway Dr (N) at two total recorded crashes over the five-year period, which
overlaps with the No Action Alternative. These two crashes are also classified as "possible injury" or "no
injury", which are the least severe type of crashes.
The overall calculated crash rate for all study intersections ranges between 0.5 to 0.7, which is lower
than the Washington state average of 1.0 to 1.5. This indicates that the crash rates for all study
intersections are low across the board. Therefore, there would be no further crash rate analyses beyond
data presented in the tables above.
207
4.6.4.4 Pavement Conditions Results
Pavement Conditions Index (PCI) data, Truck VMT, and roadway area for the alternatives' truck routes
were gathered from the City of Tukwila Public Works Department and calculated. Data is shown in Table
20 below. The PCI along each truck route varies for each alternative and is shown to provide a baseline
for existing pavement conditions. Truck VMT and the total roadway area for each alternative also varies
significantly.
Table 4.6-11 Comparison of PCI between Alternatives
Alternative
Lowest and Highest PCI
Rating
Truck VMT (annual)
Roadway Areas (sq. ft.)
No Action Alternative
Lowest PCI Rating: 41.2
(Marginal)
Highest PCI Rating: 89.3
(Excellent)
5,190,000
2,002,200
Alternative 2
Lowest PCI Rating: 36.2
(Poor)
Highest PCI Rating: 88
(Excellent)
5,059,000
1,951,500
Alternative 3B
Lowest PCI Rating: 52.7
(Fair)
Highest PCI Rating: 89.3
(Excellent)
3,646,000
1,406,600
Alternative 4
Lowest PCI Rating: 57.3
(Fair)
Highest PCI Rating: 64.6
(Good)
8,672,000
3,345,400
Figure 4.6-4 shows the PCI for all roadway segments in the City and the alternative footprints.
208
(IL /11111111
re )11 gory
001!INP?
?
( 11 11 !
ill f!
k toinii ,))1 Ili i iliiitit'
iql '
L'orkwo,
;18 fttlii485-4,
offirifin4604. 10, j j 11171111111"'"'"ic ,
4,882,442.8., rtri,
Figure 4.6-4 Pavement Condition Index (PCI) of the City of Tukwila
.41,412„„
209
CITY OF" TUKWILA
ALLENTOWN ELS
TRANSPORTATION
Pavement
Conditi,on
Atternative Project
ootpOoto
Tekvville City Lirrettt
Pavement Condittort
Index PCrit)
82,882. 0 to 25 - Vttry fil0tot
25 to 40 - Pooi
nen— 10 to 50 tolotyinal
be to GO • Hair
8,0 to 70 - Good
titintex 78 to 85 - y Geed
met- 85 to 100 - Excellent
Dale: 6/642025
620 Feet
Comparing the truck VMT and total square footage of pavement for each build alternative, Alternative 4
would have the greatest impact to the existing roadway condition due to the largest truck VMT and total
pavement square footage, resulting in an increase pavement degradation compared to the No Action
alternative. This can be attributed to the total length of the truck route being the greatest for all
alternatives.
Alternative 2 and Alternative 3B both result in a smaller truck VMT and pavement area compared to the
No Action. This can be attributed to the shorter length of truck route compared to the No Action
alternative. This may result in prolonging the service life of portions of exiting pavement along the
roadway segments that will see a reduction in truck VMT compared to the No Action alternative.
4.6.4.5 Summary of Impacts by Alternative
A summary of the construction and operational impacts for the variables considered including LOS,
AADT, crash data, and PCI data for the proposed project alternatives are presented in Table 4.6-12.
Construction and operational impacts are similar, as the routes being used during these two phases are
assumed to be similar.
Table 4.6.12 Impact Summary Table
Magnitude of Impacts for Variables in the Transportation Analysis'
Alternative
Level of Service
(LOS)
Vehicle Miles Traveled
(VMT)
Pavement
Conditions
No Action
Minor
Minor
Minor
2
Minor
Minor
Minor
3B
Minor
Minor
Minor
4
Significant
Moderate
Minor
1 If a resource has more than one magnitude of impact (i.e. a range of impacts), the highest level is
used in this chart for conservative comparison.
4.6.5 Mitigation Measures
The proposed Project would not result in operational degradation of the transportation system within
the study area. Future decline in LOS for the year 2045 is due to an assumed 1% annual increase in
natural traffic volume growth. LOS and Delay results for 2045 indicate that, without improvements,
several intersections will experience severe congestion. Martin Luther King Jr Way South/South 129th
Street (Alternative 4) is expected to continue facing substantial delays, resulting in LOS F with delays
exceeding 300 seconds per vehicle. General measures such as retiming and coordinating traffic signals
would improve the LOS.
In the long term, opportunities for multimodal integration should be explored to reduce dependency on
vehicular traffic to reduce AADT. Enhancing pedestrian and bicycle facilities, as well as planning phased
infrastructure investments, would help accommodate incremental traffic growth while minimizing
210
disruptions during construction. Finally, engaging local stakeholders, including residents and businesses,
will be critical to addressing community concerns related to traffic impacts and environmental
considerations. Collaboration with the WSDOT would help to align local improvements with regional
transportation goals, fostering a cohesive and sustainable transportation network for Tukwila.
For pavement conditions, the City has designated various treatment conditions for the pavements as
corresponding to the pavement scores. Preventative maintenance or surface treatment strategies are
recommended for areas with a PCI rating of 70 to 100, overlays (thin, moderate, thick) are
recommended for pavements with PCI ratings of 40 to 70, and reconstruction (base or surface) is
recommended for pavements with PCI ratings of 0 to 40. Pavements in the study area are mostly rated
'Good' which indicates that overlays are recommended. Specific mitigation strategies related to the
project would have to be proposed by the City, if needed.
Short-term Traffic Mitigation Recommendations:
• Implement signal timing adjustments at key intersections, particularly at Martin Luther King Jr
Way South/ South 129th Street, to alleviate congestion and improve overall traffic flow.
• Enhance safety features at high -crash locations, such as improved signage, road markings, and
dedicated turn lanes to reduce the likelihood of collisions and improve safety for all road users.
Long-term Traffic Mitigation Recommendations:
• Pursue capacity enhancements at critical intersections, including the addition of lanes or
advanced signal optimization, to address projected traffic growth and mitigate future
congestion.
• Implementing Alternative 3B may help balance the distribution of traffic volumes and minimize
delays across the network. This alternative may also offer environmental benefits by reducing
truck VMT compared to other options.
• Consider multimodal integration opportunities, such as enhancing pedestrian and bicycle
facilities, to reduce vehicular dependency and promote sustainable transportation options.
211
4.7 Health and Safety
This section describes the potential environmental health and safety hazards that may result from
construction and operation of the proposed Project's Alternatives 2, 3B, and 4 as well as from the No
Action Alternative. Risks to environmental health and safety could occur during construction or during
operations. The risks may include fire or explosion; electrical and mechanical hazards; inadvertent
release of hazardous materials; and exposure to existing hazardous materials sites. The potential
exposure to such risks by the public, construction workers, and employees during operations are
evaluated. Potential mitigation measures are also identified in this section.
Health and safety concerns relating to pedestrians and vehicle traffic are discussed in Section 4.6.
4.7.1 Affected Environment
The study area for the environmental health and safety analysis is a 0.5-mile radius from the footprint of
each alternative. A 0.5-mile search radius was used to match the ASTM-defined search radius for state -
listed contaminated sites. Known hazardous materials sites and hazardous materials cleanup sites within
0.5 mile from each alternative are identified below. Natural hazards, such as flooding or volcanic
eruptions are addressed in their respective resource sections (Section 4.1 and Section 4.2).
4.7.1.1 Hazardous Materials and Sites
Hazardous materials are materials that, because of their chemical, physical, or biological properties,
pose a potential risk to life, health, the environment, or property when not properly contained.
A survey of known contaminated sites within the study area was conducted using the Washington State
Department of Ecology's (Ecology's) online system (Ecology 2024a). In total, 58 sites were mapped
within the 0.5-mile study areas of Alternatives 2, 3B, and 4 and the No Action Alternative. Of these sites,
22 were identified as either awaiting cleanup or have had cleanup activities started. The remaining sites
were excluded from further analysis based on regulatory status. It is important to note that due to the
long-term history of development and heavy industrial use in the area, including rail operations at the
BNSF South Seattle Intermodal Facility, hazardous materials may be present in soil and groundwater
that have not been identified by the Ecology database.
In addition to the confirmed or suspected contaminated sites listed below for each alternative, all of the
alternatives are located within the mapped Tacoma Smelter Plume (Ecology 2024b). Alternatives 2 and 4
are mapped as an area with less than 20 parts per million (ppm) predicted arsenic concentrations in soil.
Predicted arsenic concentrations range from 20 to 40 ppm for Alternative 3B and the No Action
Alternative. Model Toxic Controls Act Method A cleanup levels for arsenic is 20 ppm (Ecology 2024b).
Table 4.7-1 through Table 4.7-4 summarize the confirmed and suspected contaminated sites within 0.5
mile of each alternative. Due to each alternative's relatively close proximity to each other, the same
confirmed or suspected contaminated site may be listed under one or more alternative. Figure 4.7-1
through Figure 4.7-5 show the locations of each site in relation to each alternative.
212
Affected Media and Contaminants Confirmed
and Suspected above Cleanup Levels
Metals priority pollutants, non -halogenated
solvents, lead, benzene, petroleum products
confirmed in soil and groundwater
Petroleum products confirmed in soil and
groundwater
Arsenic and metals priority pollutants
confirmed in soil; arsenic confirmed in
groundwater
Benzene, petroleum products confirmed in
soils and groundwater
Beneze and petroleum products confirmed in
soil and groundwater
Benzene and petroleum hydrocarbons
confirmed in groundwater; petroleum
products confirmed in soils
Address
12677E Marginal Way S
4105 S 139th St
4501 S 134th St
12100 12200 E Marginal Way S
13310 Interurban Ave S
13138 Interurban Ave S
Site Status
Cleanup
Started
Awaiting
Cleanup
Cleanup
Started
Cleanup
Started
Cleanup
Started
Cleanup
Started
Cleanup
Site Id
0
N
m
m
.--1
N
0
N
Ln
N
01
L
Site Name
C & D Wells LLC
Crowell Residence
Fostoria Gardens
King County Metro Transit South
Base
Peterson Tukwila 76
Shell 120598
0
N
N
Affected Media and Contaminants Confirmed and Suspected
above Cleanup Levels
Metals priority pollutants, non -halogenated solvents,
Polycyclic Aromatic Hydrocarbons (PAHs), and petroleum
products suspected in soils. Metals priority pollutants, non -
halogenated solvents, PAHs, and petroleum products
confirmed or suspected in soils.
Confirmed petroleum products in soil; suspected in
groundwater
Benzene, non -halogenated solvents, petroleum products
confirmed in soils and groundwater
Confirmed PCBs in soils; suspected in groundwater
Confirmed halogenated pesticides, lead, metals -other,
petroleum products, PCBs, and PAHs in soil. Petroleum
products and PAHs confirmed in groundwater.
Benzene, petroleum products confirmed in soil and
groundwater
Halogenated organics, non -halogenated solvents, petroleum
hydrocarbons confirmed in groundwater, and confirmed and
suspected in soil
Confirmed benzene and petroleum products in soil; suspected
in groundwater
Confirmed metals in groundwater, confirmed PAHs and
petroleum products in soil
Suspected and confirmed halogenated organics, metals, non -
halogenated solvents, PCBs, and petroleum products in soil
and groundwater
Confirmed arsenic, lead, petroleum products and PAHs in soils
Confirmed or suspected arsenic, metals priority pollutants,
and petroleum products in soil and groundwater
Address
9802 Martin Luther King Jr Way S
S Norfolk St & Airport Way S
10805 Tukwila International Blvd
10002E Marginal Way S
11244 Tukwila International Blvd
9834 9840 Martin Luther King Jr
Way S
3301 S Norfolk St
10710 E Marginal S & 10650 27th S
2724 S 112TH St
10230E Marginal Way S
11030E Marginal Way S
11210 Tukwila International Blvd
Site Status
Awaiting
Cleanup
Cleanup
Started
Cleanup
Started
Cleanup
Started
Awaiting
Cleanup
Cleanup
Started
Cleanup
Started
Cleanup
Started
Cleanup
Started
Cleanup
Started
Awaiting
Cleanup
Awaiting
Cleanup
Cleanup
Site Id
OO^
12904
�f1
lD
N
CO
00
16604
W
Site Name
Affordable Auto Wrecking
BNSF Locomotive Spill
Boeing Field Chevron
Boeing Military Flight Center
Chinook Wind
Easteys ARCO
Emerald Gateway
McConkey Property
North Winds Weir Intertidal
Restoration
Northwest Auto Wrecking
Seattle Police Athletic
Association
Triad Machinery Inc Tukwila
N
N
y
vvv—
Affected Media and Contaminants
Confirmed and Suspected above Cleanup
Levels
Confirmed benzene, lead, methyl tertiary -
butyl ether, non -halogenated solvents, and
petroleum hydrocarbons in soils and
groundwater
Arsenic and metals priority pollutants
confirmed in soil; arsenic confirmed in
groundwater
Arsenic, benzene, lead, petroleum products
confirmed or suspected in groundwater;
benzene, petroleum products confirmed or
suspected in soils
Arsenic, benzene, lead, petroleum products
confirmed or suspected in groundwater;
benzene, petroleum products confirmed or
suspected in soils
Beneze and petroleum products confirmed
in soil and groundwater
Benzene and petroleum hydrocarbons
confirmed in groundwater; petroleum
products confirmed in soils
Address
12911 Martin Luther King Jr Way
S
4501 S 134th St
12840 48th Ave S
12840 48th Ave S
13310 Interurban Ave S
13138 Interurban Ave S
Site Status
Cleanup
Started
Cleanup
Started
Cleanup
Started
Cleanup
Started
Cleanup
Started
Cleanup
Started
Cleanup
Site Id
,—IN
d-
01
.--1
N
N
N
00
N
N
00
d-
i.f1
N
m
01
L
Site Name
Exxon 72894
Fostoria Gardens
Penske Truck Leasing 1990
Penske Truck Leasing 1994
Peterson Tukwila 76
Shell 120598
uu
Affected Media and Contaminants
Confirmed and Suspected above Cleanup
Levels
Metals priority pollutants, non -halogenated
solvents, PAHs, and petroleum products
suspected in groundwater. Metals priority
pollutants, non -halogenated solvents, PAHs,
and petroleum hydrocarbons confirmed or
suspected in soils.
Suspected petroleum products in soil and
groundwater
Benzene, petroleum hydrocarbons
confirmed in soil and groundwater
Confirmed benzene, lead, methyl tertiary -
butyl ether, non -halogenated solvents, and
petroleum hydrocarbons in soils and
groundwater
Arsenic, benzene lead, petroleum products
confirmed or suspected in groundwater;
benzene, petroleum hydrocarbons
confirmed or suspected in soils
Benzene and petroleum products confirmed
in soil and groundwater
Confirmed arsenic, lead, metals, petroleum
products, and PAHs above cleanup levels in
soil
Benzene and petroleum products confirmed
in groundwater; petroleum products
confirmed in soils
Address
9802 Martin Luther King Jr Way S
13001 Martin Luther King Jr Way
S
9834 9840 Martin Luther King Jr
Way S
12911 Martin Luther King Jr Way
S
12840 48th Ave S
13310 Interurban Ave S
11030E Marginal Way S
13138 Interurban Ave S
Site Status
bI Q
v
< 0
Awaiting
Cleanup
Cleanup
Started
Cleanup
Started
Cleanup
Started
Cleanup
Started
Awaiting
Cleanup
Cleanup
Started
Cleanup
Site Id
co
lD
m
Ln
,--I
cn
n
co
d-
N
16604
m
Ln
Site Name
Affordable Auto Wrecking
Building Busters
Easteys ARCO
Exxon 72894
Penske Truck Leasing 1990
Peterson Tukwila 76
Seattle Police Athletic
Association
Shell 120598
Li
1/1
E
4.7.2 Relevant Plans Policies and Regulations
This section summarizes federal, state, and local regulations related tohealth and safety that are applicable
to the proposed Project. Relevant policies and regulations related to health and safety are summarized in
Table 47'5.
Table 4.7 5. Applicable Policies ond Regulationsfor Hea/t/,7 ond Safety
Federal
Pipeline and Hazardous Materials Safety
Administmtion(PHyWSA)
(49CFR105-11land 171-180'19O'195)
Regulates the movement ofhazardous materials.
Limits onLiability (33USC27O4)
Establishes limits onliability ofuresponsible party to
incur costsfromcertain types ofincidents.
Hazardous Materials Transportation Act
(49USC51)
Authorizing Act for all aspects ofhazardous materials
packaging, handling, and transportation for vessel,
truck, and rail. Requirements enforced byPHyWSA(listed
above).
Comprehensive Environmental Response,
Compensation and Liability Act (40CFR300'
302)
response
hazardous substance releases tothe environment and
liability forresponsib|eparties for response actions
and damage tonatural resources.
Occupational Safety and Health (29CFR
1904,1910)
Regulates emergency planning and response,
indudinguircontaminant exposure limits for
workers.
SuperfundAmendment and
Reauthorization Act (40CFR302)
Amended CERCLAand requires reporting for emergency
response, emergency release, and hazardous and toxic
chemical releases.
Federal Resource Conservation and Recovery
Act (42USC6901etseqJ
Governs the generation, storage, and transportation of
hazardous waste and waste management activities for
hazardous waste treatment, storage, and disposal
facilities. This isudelegated Washington State program
under the Washington HuzurdousVVusteManagement
Act.
Toxic Substances Control Act
(15 USC26O1—Z629)
Tracks industrial chemicals inthe United States
and regulates intrastate and interstate commerce.
Department ofTransportation Hazardous
Materials Regulations
(49CFR100-185)
Protect against the risks to life, property, and the
environmentundapply toall interstate, intrastate, and
foreign transport ofhazardous materials incommerce.
State: Washington
Pollution Prevention Plan Requirements
(VVAC173'3O7)
Requirements for Pollution Prevention Plans
associated with hazardous substance users and
waste generators.
Washington Industrial Health and Safety Act
(RCVV49.17)
Regulates emergency planning and response, inc|udinguir
contaminant exposure limits forworkers.
222
Laws and Regulations
Description
Model Toxics Control Act and its
implementing regulations
(RCW 70.105D and WAC 173 340)
Requires potentially liable persons to assume
responsibility for cleaning up contaminated sites.
Requires reporting hazardous substance releases if they
constitute a threat to human health or the environment.
Washington Administrative Code (WAC
173 340 300)
Requires reporting hazardous substance releases if they
constitute a threat to human health or the
environment.
General Occupational Health Standards
(WAC 296-62)
Protect the health of employees and help create a
healthy work place by establishing requirements to
control health hazards including chemical hazard
communication and exposure programs.
Local
TMC Title 21 Environmental Regulations
Code 17.02
City environmental policy adheres to State SEPA policy
and Ecology rules and regulations.
King County Code, Chapter 20.44.085
King County is required under RCW 43.21C.120 to
adopt rules pertaining to the integration of the
policies and procedures ofthe State SEPA into
programs within King County'sjurisdiction.
King County rules are consistent those of the Ecology,
Chapter 197-11 WAC.
City of Seattle Municipal Code 25.05
City environmental policy adheres to State SEPA
policy and Ecology rules and regulations.
4.7.3 Methodology
Potential impacts on environmental health and safety were evaluated based on the applicable federal,
state, and local regulatory frameworks, as well as health and safety related to construction and
operation of the proposed Project Alternatives.
Potential impacts are discussed in qualitative terms and are evaluated based on the definitions listed in
Table 4.7-6.
Table 4.7-6. Impact Magnitude and Description
Magnitude of Impact
Description
No Impact
The proposed Project would not result in any impacts to health and safety.
Minor
The proposed Project would result in temporary impacts to health and safety
Moderate
The proposed Project either would result in permanent impacts to health and
safety that have been mitigated to be less than significant
Significant
The proposed Project would result in significant permanent impacts that cannot be
mitigated to be less than significant.
223
4.7.4 Impacts Analysis
4.7.4.1 No Action Alternative
Moderate Impact. The No Action Alternative would not result in the potential for release of
contaminants. However, any existing health and safety hazards, including contaminated soils and
groundwater would remain within the study area. In addition, the potential for spills or release during
transport and operations would continue, resulting in potential impacts to the public and employees.
These potential impacts would be minor due to requirements that if a release of hazardous materials
were to occur, emergency response and cleanup measures would be implemented as mandated by
federal and state laws, including Washington State regulations under Revised Code of Washington
(RCW) 90.56.The transport of hazardous materials during operations will comply with applicable federal
and state regulations identified in Table 4.7-1 under the No Action Alternative.
4.7.4.2 Impacts Common to All Build Alternatives
4.7.4.2..1. Construction Hazards
Moderate Impact. Various site preparation activities are proposed, including, but not limited to,
clearing, grading, and roadway construction. During construction of proposed Alternatives 2, 3B, or 4,
construction workers could experience typical construction hazards including trips, slips, and falls;
electrical or mechanical hazards; overhead hazards from cranes or excavators; and risk of blunt force
trauma from accidents with machinery.
Hazardous materials likely to be transported through the proposed Project site during construction
include materials typical of construction projects and would generally be used and handled in relatively
small quantities. Impacts from releases would likely be localized and short term in nature, although fuel
spills could reach and affect the Duwamish River. Any spills that occur would require reporting and
response as required by federal and state laws. The transport of hazardous materials would be
compliant with applicable federal and state regulations such as the Resource Conservation and Recovery
Act, U.S. Department of Transportation Hazardous Materials Regulations, and other regulations
identified in the Regulatory Framework in Table 4.7-5.
Construction workers could also be exposed to inadvertent release of hazardous materials. Hazardous
materials likely to be present during construction would include materials typical of construction
projects, which are generally handled and used in relatively small quantities and include fuels and
lubricant oils for construction vehicles and equipment. Diesel fuel is the primary potentially hazardous
substance that could be used in a significant quantity during construction. Construction of the proposed
Project could expose hazardous materials in the proposed Project site that pose risks to human health
and the environment through contact with contaminated soil, contaminated groundwater, and
inhalation of toxic vapors. The selected contractor should be required to provide an emergency response
plan and practice proper hazardous material storage, handling, and emergency procedures including spill
notification and response requirements in accordance with RCW 49.17 and WAC 173-303.
Contractors would be required develop a Project Health and Safety Plan (HASP) prior to construction for
all phases of the proposed Project, which would mitigate risks to construction workers as required by
Washington Administrative Code 296-800-100. The HASP would be implemented to manage and control
224
safety risks, as well as to guide responses in the case of emergency situations during construction,
including evacuation plans.
Based on these considerations, public and occupational health and safety risks during construction of
the proposed Project include the potential exposure to electrical and mechanical hazards for
construction workers, inadvertent release of hazardous materials, and exposure to existing hazardous
materials sites. A moderate impact, from implementation of the proposed Project, is anticipated.
4.7.4.2..2. Operations impacts
4.7.4.2.2.1 Inadvertent Release of Hazardous Materials
Moderate Impact. Hazardous materials may be transported to the BNSF intermodal facility. Petroleum
products, such as fuel used in truck transport or hazardous materials transported to the BNSF
intermodal facility, are potentially hazardous if accidentally released to the environment. These
products could threaten plant and animal species, particularly aquatic life, such as that found in the
Duwamish River. Spills of these products during truck transport could impact the public, soil,
groundwater, surface waters, plants, and animals. If a release of hazardous materials were to occur,
emergency response and cleanup measures would be implemented as required by federal and state
laws, including Washington State regulations under Revised Code of Washington (RCW) 90.56. Similar to
the No Action Alternative, any spills that could occur would require reporting and responding as
required by federal, state, and local laws. The transport of hazardous materials during operations would
be in compliance with the applicable federal and state regulations identified in Table 4.7-5. The
proposed Project would not result in a change to BNSF operations or volume of hazardous materials
transported to its facility. Therefore, the impact from the inadvertent release of hazardous materials
during the operation of the proposed Project would be the same moderate impact as the No Action
Alternative.
4.7.5 Mitigation Measures
Below is a description of the mitigation measures that would be available to minimize or avoid impacts
health and safety from construction and operations of the proposed Project. Mitigation measures would
be common to Alternatives 2, 3B, and 4.
A. HS-1: Prepare a Project Health and Safety Plan. In accordance with RCW 49.17, in order to
ensure worker safety on site during construction, the selected Contractor should be
required develop a HASP prior to construction of the Project. The HASP would be
implemented to manage and control safety risks as well as to guide responses in the case of
emergency situations during construction. The HASP should be provided to the permitting
agency prior to permit issuance.
B. HS-2: Prepare Emergency Response Plan. The selected Contractor should be required to
provide an emergency response plan and practice proper hazardous material storage,
handling, and emergency procedures including spill notification and response requirements
in accordance with RCW 49.17 and WAC 173-303. The emergency response plan should be
provided to the permitting agency prior to permit issuance. Best Management Practices
(BMPs) would be in place to minimize impacts on environmental health. Implementation of
appropriate spill prevention and control measures would ensure that the risk of an
225
accidental release of hazardous materials remains low throughout construction of the
Project.
C. HS-3: Comply with Model Toxics Control Act Regulations for Unexpected Encounter with
Hazardous Materials. The permitting agency would be required to inform the City and
contractors that they are instructed to immediately stop subsurface activities if potentially
hazardous materials are encountered, or significantly stained soil is found, during
construction. Contractors would be instructed to follow applicable regulations including the
Model Toxics Control Act and its implementing regulations (RCW 70.105D and WAC 173-
340) regarding discovery and response for hazardous materials encountered during the
construction process.
D. HS-4: Comply with Washington Industrial Safety and Health Act (WISHA) Rules. The
permitting agency would be required to inform the City and contractors that they are
required to comply with WISHA rules that protect workers from hazardous job conditions.
WISHA regulates an array of occupational hazards in WAC 296 (Safety Standards for
Construction Work) such as safety standards for construction work (WAC 296-155), general
safety and health standards (WAC 296-24), and general occupational health standards (WAC
296-62).
226
.4.8 Pullsiic Services and Uthiitiies
This section describes the potential impacts to public services (fire, police, and medical) and utilities
(water, sewer, and stormwater; natural gas; electrical facilities; and solid waste services) that may result
from construction and operation of the proposed Project. Potential mitigation measures are also
identified in this section.
4.8.1 Affected Environment
The study area for the public services and utilities analysis is the service areas of the public service
agencies and utility providers in relation to proposed Project build alternatives and the No Action
Alternative. Table 4.8-1 lists the existing utilities services and providers for each Alternative
Table 4.8-1 Utility Services and Providers within the Study Area
Service
Provider
Police/Sheriff
City of Tukwila, Seattle Police Department, King County Sheriff's Department,
Washington State Patrol
Fire
Puget Sound Regional Fire Authority; King County Fire Protection District No. 20,
Seattle Fire Department
Medical
St. Anne Medical Center in Burien and Valley Medical Center
Domestic Water
Skyway Water and Sewer District, City of Tukwila, Seattle Public Utilities
Stormwater
King County Department of Natural Resources and Parks — Stormwater Services
Section, Seattle Public Utilities, City of Tukwila Public Works Department
Electrical Facilities
Seattle City Light
Solid Waste
Recology, City of Seattle, Waste Management
4.8.1.1 Police and Sheriff Services
The City of Tukwila Police Department, Seattle Police Department, King County Sherriff's Department,
and the Washington State Patrol provide law enforcement services to the jurisdictions that include the
Alternatives of the proposed Project.
The Tukwila Police Department employs approximately 77 commissioned officers. The law enforcement
services provided include patrol, traffic units, K-9 units, marine unit, and administrative (City 2022a). The
nearest Tukwila Police Department is located approximately 1.5 miles southwest of Alternative 3B.
The King County Sheriff's Office employs over 1,000 uniformed and professional staff and provides air
support, search and rescue, marine rescue, and patrol. King County Sheriff's Office also provides services
to Muckleshoot Tribal Lands, Metro Transit, King County International Airport (Boeing Field), and 12
cities (King County 2024e).
The Seattle Police Department is the largest municipal law enforcement agency in Washington state,
with 1,200 authorized sworn officers and 631 civilian employees. Law enforcement services include foot,
car, and bike patrols; harbor patrol of 59 square miles of waterway; traffic and parking enforcement;
and K-9 units (City of Seattle 2024b).
227
The Washington State Patrol provides traffic law enforcement on state highways and drug law
enforcement, Hazardous Materials Team oversight, and incident response services. The Washington
State Patrol Field Operations Bureau oversees eight districts within the state. District 2 serves King
County, and the field office for District 2 is located in Bellevue, WA (WSP 2020).
4.8.1.2 Fire Services
Fire services for the proposed Project Alternatives and the surrounding area are provided by the Puget
Sound Regional Fire Authority, King County Fire District 20, and the Seattle Fire Department (Station 33).
The City of Tukwila contracts out fire and EMS services to the Puget Sound Regional Fire Authority. The
Puget Sound Fire Authority employs 345 uniformed personnel and provides emergency and non -
emergency services to the communities of Covington, Kent, Maple Valley, SeaTac, and parts of
unincorporated King County, in addition to the City of Tukwila. Puget Sound Regional Fire Authority has
17 fire stations to provide services to an approximately 120 square mile area (Puget Sound Regional Fire
Authority 2024).
King County Fire Protection District No. 20 provides emergency services to an approximately three -
square -mile service area in the West Hill Community of King County.
In total, the Seattle Fire Department has 995 uniformed personnel, including firefighters, emergency
medical technicians, and chiefs. The department also employs 85 civilian personnel (Seattle Fire
Department 2023).
4.8.1.3 Medical
Two hospitals are located near the study area: St. Anne Medical Center in Burien, and Valley Medical
Center located in Renton, which is part of University of Washington Medicine. Both are full -service
hospitals with emergency rooms. St. Anne Medical Center is located approximately four miles southwest
of Alternative 3B. Valley Medical Center is located approximately 3.7 miles southeast of Alternative 4.
4.8.1.4 Domestic Water
The water supply for the proposed Project Alternatives and the surrounding service area is provided by a
combination of the City of Tukwila's Public Works Department, Skyway Water and Sewer District, and
Seattle Public Utilities. The City of Tukwila's water service area covers approximately 8.6 square miles,
and per the 2015 Comprehensive Plan, includes approximately 45 miles of transmission and distribution
pipelines. The City of Tukwila's drinking water comes from the Cedar River Watershed, which is owned
and maintained by Seattle Public Utilities. The City is a member of the Cascade Water Alliance, which is a
group of seven municipalities that collectively purchase water from Seattle Public Utilities (City 2022b).
The Skyway Water and Sewer District service area is approximately 1.8 square miles for water (serving
3,400 customers). The Skyway Water and Sewer District maintains approximately 40 miles of water
mains.
Seattle Public Utilities water supply comes from one of two watersheds: approximately 30 to 40 percent
of the water supply comes from the Tolt River Watershed, and the remaining 60 to 70 percent of the
water supply come from Cedar River Watershed. In total, Seattle Public Utilities provides water to 1.6
million people in the greater Seattle area (Seattle Public Utilities 2024).
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4.8.1.5 Stormwater
Stormwater within and adjacent to the proposed Project Alternatives is managed by King County
Department of Natural Resources and Parks — Stormwater Services Section, Seattle Public Utilities, and
City of Tukwila Public Works Department. These municipalities regulate stormwater discharges via
Tukwila Municipal Code (TMC) 14.30, Seattle Municipal Code (SMC) 22.800, and Title 9 of King County
Code (KCC).
4.8.1.6 Sewer
Sewer collection service within the study area is provided by the Skyway Water and Sewer District,
Seattle Public Utilities, and the City of Tukwila. These three jurisdictions own and operate independent
collection systems, which include pipelines and pump stations to collect and carry wastewater flows in
their service area, which then flow to King County's regional system for treatment and disposal. King
County owns and operates the regional treatment plants, pipelines, pump stations, and other related
facilities. The Skyway Water and Sewer District service area is approximately 2.7 square miles for sewer
(serving 4,100 customers). The District maintains approximately 48 miles of sewer system piping. The
SPU system collects residential, commercial, and industrial sewage and delivers it to interceptor lines
operated by the regional sewage treatment agency (King County). The City of Tukwila's sewer system is
comprised of approximately of approximately 37 miles of gravity sewer main and the operation and
maintenance of 12 lift stations and force mains.
4.8.1.7 Electrical Facilities
Electrical service in the study area is provided by Seattle City Light. Seattle City Light is one of the
nation's largest municipally owned utilities serving more than 420,000 homes and 49,000 businesses
throughout Seattle, Shoreline, Lake Forest Park, Burien, Renton, Tukwila, SeaTac, Normandy Park, and
Unincorporated King County. Hydroelectric plants generate approximately 88 percent of Seattle City
Light's electricity. Remaining electrical service is generated by wind, nuclear, biogas, and other
unspecified sources.
4.8.1.8 Solid Waste
Starting in 2023, solid waste services within the City of Tukwila are provided by Recology, with the City
signing a 10-year contract with the company. Recology provides both residential and business solid
waste services. The City of Seattle provides solid waste services for the portion of Alternative 2 located
within that jurisdiction. Domestic and commercial solid waste services are provided by private providers
within unincorporated King County. For the portion of Alternative 4 located in King County, solid waste
services are provided by Waste Management. Solid waste in the study area is ultimately taken to King
County's Cedar Hill Landfill for disposal.
4.8.2 Relevant Plans Policies and Regulations
This section summarizes state and local regulations related to public services and utilities that are
applicable to the proposed Project. There are no federal regulations applicable to the proposed Project.
Relevant policies and regulations related to public services and utilities are summarized in Table 4.8-2.
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Toble 4.8 2. Applicoble Policies ond Regulationsfor Public Services ond Utilities
Policies and 116itilaticins
bescriptio'n'
State
Washington Administrative Code
The Washington Administrative Code (VVAC)includes water quality
standards that are implemented utthe local municipality level. Relevant
standards that guide stormmmtermanagement and site development
manuals, include:
* Chapter 173'2OOofthe VVAC Water Quality Standards for
Groundwutenofthe State ofWashington
* Chapter 173'201AVVAC Water Quality Standards for Surface Waters
ofthe State ofWashington
* Chapter 173'2O4VVAC Sediment Management Standards.
Washington State Growth
Management Act (GyWA)
Under the GyWA(Revised Code ofWashington 36JUA),certain counties and
cities must create and regularly update comprehensive plans toidentify
where growth will occur and toplan for housing, transportation, water,
sewer, natural gas, electrical lines, and other necessary facilities.
Jurisdictions under the GyWAare required tohave ucapital facilities' plan
element within their comprehensive plans. The capital facilities element
requires u forecast of future needs, expansions or new facilities, locations,
and capacities of expanded or new facilities and a 6-year plan for financing.
The land use element, capital facilities element, and financing plan must all
becoordinated and consistent.
Washington Department of
Ecology StormmmterWater
Quality Regulations
Ecology has the authority to issue stormmmterpermits guided by both the
federal water pollution permit program, known usthe National Pollutant
Discharge System (NPDES), and also state water quality laws. Stormmmter
permits vary from water quality general for releasing treated stormwuteror
wastewater discharge toeither surface orgroundwater; Construction
StormwuterGeneral Permit tocontrol and reduce water pollution during
construction; and Municipal Stormwuter NPDES.
Local
City ofTukwila Comprehensive
Plan, Utilities Element
The City ofTukwila Comprehensive Plan includes uchapter that identifies
goals and policies for utilities. The City of Tukwila Comprehensive Plan has
goals and policies inthe Utilities Element that address public services and
utilities, including:
* Policy 12.1.7: Participate in the regulation of all water, sewer and surface
water utility services within the City'seventual boundaries.
* Policy 12l10: Establish and maintain franchises and working agreements
with sewer and water utilities currently operating within the City limits,
toensure that the level ofservice provided isconsistent with the Cit/s
requirements and neighborhood revitalization plans.
City ofSeattle Comprehensive
Plan
The City ofSeattle Comprehensive Plan includes uchapter that identifies
goals and policies for public services and utilities, including:
* Goal UG5Work with non -City utilities topromote the Cit/soverall goals
for utility service and coordinated construction within the right*f+muy
* Policy U 5.1 Provide affected non -City utilities with timely and effective
notices ofplanned road and right*f+muytrenching, maintenance, and
upgrade activities.
King County Comprehensive Plan
King County Comprehensive Plan includes uchapter that identifies goals and
policies for utilities, including:
* F-1O1King County, the cities, special purpose districts orlocal service
providers shall plan uspartners.
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Policies and Regulations
Description
• F-102 King County shall work with cities, special purpose districts, other
local service providers and residents to identify and distinguish local,
countywide and regional services.
• F-204 King County should work with the cities, special purpose districts
and other service providers to define regional and local services and to
determine the appropriate providers of those services.
City of Tukwila Code
Tukwila Municipal Code (TMC) 14.30, regulates development activities that
could affect stormwater and non-stormwater discharges to the stormwater
drainage system, including establishing the methods for controlling the
introduction of pollutants into the stormwater drainage system.
City of Seattle Code
The City of Seattle regulates stormwater under SMC 22.800, which is also
referred to as the Stormwater Manual. Part of the purpose of this code is to
meet the requirements of state and federal law and the City of Seattle's
municipal stormwater NPDES permit and to protect the public drainage
system from loss, injury and damage.
King County Code
Title 9 of KCC is the Surface Wate, Stormwater, and Groundwater
Management Manual. The purpose of this Chapter is to promote the public
health, safety and welfare by providing for the comprehensive management
of stormwater runoff and surface water and erosion control.
4.8.3 Methodology
The public services and utilities analysis evaluates the proposed Project's potential to result in conflicts
and/or plan inconsistencies that would result in significant impacts on public services and utilities. The
section was written following review of publicly available plan information from the affected public
service and utility providers. This section also evaluates the proposed Project's potential to introduce
facilities or components that could result in localized public service and utility conflicts or plan
inconsistencies. If the proposed Project is determined to be inconsistent with the provision of public
services or utilities, or inconsistent with plans for serving the area as future development occurs, an
impact would occur. A significant impact would occur if the proposed Project would result in irreversible
interruptions to public services and utilities in the area that cannot be addressed via mitigation or would
be inconsistent with local growth and demand for services that cannot be addressed via mitigation.
4.8.4 Impacts Analysis
This section describes the potential environmental impacts related to public services and utilities as a
result of Project implementation. Potential impacts are discussed in qualitative terms are evaluated
based on the definitions listed in Table 4.8-3.
Table 4.8-..3. Impact Magnitude and Description
Magnitude of Impact
Description
No Impact
The project would not result in any impacts to public services.
Minor
The project would result in temporary impacts to public services.
Moderate
The project would result in permanent impacts to public services that can be
mitigated for.
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Magnitude of Impact
Description
Significant
The proposed Project would result in significant permanent impacts to public
services that cannot be mitigated for.
4.8.4.1 No Action Alternative
No Impact. Under the No Action Alternative, the truck traffic traveling to and from the BNSF intermodal
facility would continue under current operating conditions. No changes to existing public services or
utilities would occur as a result of Project activities, and no additional impacts would occur with the
continued operation of this alternative.
4.8.4.2 Construction Impacts
This section includes the general impacts that would be common to Alternatives 2, 3B, and 4.
4.8.4.2..1 police and Sheriff Services
Minor Impact. During construction, police services would be provided by the City of Tukwila, Seattle
Police Department, and/or King County Sheriff's Department. These jurisdictions may provide traffic
control services for City or County right-of-way (ROW) if construction would necessitate law
enforcement traffic control services by a uniformed officer(s).
Construction activities would result in increased traffic to and from the proposed Project and an
increased presence of construction materials and equipment. Emergency response times may increase
due to increased traffic. The addition of construction equipment may lead to service calls for property
crimes such as theft or vandalism.
Minor impacts to police and sheriff services from increased traffic, construction activities, and traffic
control would be intermittent and temporary, occurring over the construction period, which may create
a need for services from police and sheriff services during that time. However, the increased need would
not be at a level that would permanently interfere with or cause a decreased level of service for City of
Tukwila, Seattle Police Department, or King County Sheriff's Department; therefore, impacts would be
minor.
4.8.4.2..2. Fire Services
Minor Impact. Puget Sound Regional Fire Authority, Seattle Fire Department, and/or King County Fire
Protection District would provide fire services to the proposed Project during construction. The
increased presence of construction equipment, physical property, and vehicles may result in inadvertent
traffic delays that may affect emergency service and fire protection response times. Increased traffic
from construction could also result in a higher potential for motor vehicle collisions, which could also
require emergency services. Further, emergencies related to construction at the proposed Project site
could lead to the need for fire and emergency services, such as medical emergencies, construction
accidents, fires, and emergencies related to natural disasters that could occur in and affect the proposed
Project site.
Impacts to fire services from increased traffic, construction activities, and traffic control would be
intermittent and temporary, occurring over the construction period, which could create a need for
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emergency and fire services during that time. However, the increased need would not be at a level that
would permanently interfere with or cause a decreased level of service for fire service providers in the
study area; therefore, impacts would be minor.
4.8.4.2.3 Domestic Water
Minor Impact. Project construction would require the use of locally available water supplies that are
distributed by City of Tukwila (via the Cascade Water Alliance), Seattle Public Utilities, and/or the
Skyway Water and Sewer District. During construction, water would be required for various activities,
such as controlling dust, compacting soil, and mixing concrete. The proposed Project's construction
water demand would be minor, short-term, and temporary.
Construction of the proposed Project would be constrained to the proposed Project site and long-term
interruption of water services to adjacent parcels is not anticipated. No temporary shutoffs are
anticipated as a result of Project construction. Adjacent parcels could experience interruptions if an
unanticipated large-scale main break were to occur; however, temporary impacts would be minor.
4.8.4.2..4 Stormwater
Moderate Impact. Construction would result in ground -disturbing activities that could change drainage
patterns on site and in the immediate vicinity of the proposed Project. Prior to construction, the
Applicant would be required to comply with Ecology Stormwater Quality Regulations, obtain coverage
under the National Pollutant Discharge System through a Construction Stormwater General Permit to
help control runoff, and reduce water pollution from the construction site. Prior to construction, the
Applicant would be required to develop a SWPPP in conformance with requirements in TMC 14.30, SMC
22.800, and/or Title 9 of KCC; implement sediment erosion and pollution prevention control measures;
and receive an approved permit under the NPDES program. Therefore, impacts to stormwater are
anticipated to be Moderate.
4.8.4.2.5 Sewer
Minor Impact. Wastewater produced during construction would be minimal and would be discharged to
the municipal sewer system or hauled off site and the waste disposed of at an appropriate facility in
accordance with appropriate regulations. As such, construction of the proposed Project would not
impact sewer capacity outside of normal impacts expected during and after temporary construction
projects.
Sewer utility relocations are not anticipated for construction. However, adjacent parcels could
experience interruptions if an unanticipated large-scale main break were to occur. However, since a
main break is unlikely, impacts would be minor.
4.8.4.2.6 Electricity
Minor Impact. The proposed Project is located in a developed areas of the City of Tukwila, City of
Seattle, and King County which has existing infrastructure for electric power provided by Seattle City
Light. Construction related activities of the proposed Project would result in fuel consumption from
the use of construction tools and equipment, as well as transport of workers and materials to or from
the construction site. Electricity is not expected to be consumed in large quantities during
construction -related activities, as construction equipment is expected to be fueled with diesel,
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gasoline, or electricity. It is possible that short-term interruptions could occur during installation of
street lighting as part of construction the proposed Project. However, any service interruption would
be temporary in nature. Temporary connections to utility customers would typically be established
before planned service interruptions to minimize impacts. However, inadvertent damage to
underground utilities could occur if utility locations are uncertain or misidentified. Therefore, impacts
to electricity are anticipated to be minor.
4.8.4.2.7 Solid Waste Services
Minor Impact. Construction of the proposed Project would be limited to the proposed Project site and
would not impact or interrupt solid waste services to adjacent parcels. Construction activities would
result in an increase in solid waste services in the proposed Project site during construction; however,
no interruptions to service are anticipated. Therefore, impacts to solid waste services are anticipated to
be minor.
4.8.4..E Operations Impacts
Moderate Impact. The proposed Project is not anticipated to result in changes to BNFS's overall
operations or staffing. Therefore, with the exception of stormwater and electrical facilities, no additional
utility connections or demands are anticipated for operation of the proposed Project. Since no
additional truck or employee trips are anticipated as a result of operations, an increased need for
emergency services is not anticipated. Impacts to stormwater and electrical utilities from operation are
described below.
All of the build alternatives would result in an increase of impervious surface and therefore the amount
of surface water runoff is anticipated to increase with proposed Project operations. Onsite stormwater
would be collected and treated in accordance with the City of Tukwila, Seattle, and/or King County
guidelines and the Ecology Stormwater Management Manual for Western Washington.
Additional electrical utilities would be required for new street lighting associated with road
improvements but would not result in additional strain on existing infrastructure and would not affect
infrastructure or electricity on adjacent properties. Further, the Applicant would be required to submit
service applications to Seattle City Light to ensure adequate supply for electrical service availability;
therefore, impacts would be moderate.
4.8.5 Mitigation Measures
Below is a description of the mitigation measures that would be available to minimize or avoid impacts
public services from construction and operations of the proposed Project. Mitigation measures would be
common to Alternatives 2, 3B, and 4.
• PS-1: Utility Surveys. The applicant would conduct potholing and pre -construction surveys to
identify utility locations. The utility locations would reduce the likelihood of inadvertent service
disruptions from a main break.
• PS-2: Emergency Services Coordination. The applicant would notify and coordinate with
emergency service providers prior to the start of construction to ensure reliable emergency
access or alternative routes to minimize delays in response times.
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4.9 Cullturall Resources
This section describes the affected environment in the context of cultural resources, provides analysis of
the alternatives for potential impacts to those resources, and discusses potential mitigation. The term
cultural resources refers to the broad range of resources that represent or convey a place's heritage or
help tell the story of a region's past. Cultural resources include archaeological resources, historic built -
environment resources, and traditional cultural places (TCP). A cultural resource can be any building,
structure, object, site, landscape, or district associated with human activity or use of the environment.
Additionally, this section also describes known Tribal resources, analyzes potential impacts to such
resources, and presents potential mitigation.
Archaeological resources encompass sites, objects, features, and deposits located on or below the
ground surface that are evidence of prior human occupation or use in a particular area. Historic built -
environment resources include human -made objects, buildings, structures, sites, and districts that are
over 45 years in age and not in ruin. TCPs are sites or locations considered culturally important to the
history of a group of people or are locations where culturally important events or practices are known to
have occurred or are occurring. Additionally, ethnographic place names that although are not
documented as TCPs, potentially have significant meaning to Indian Tribes. Tribal resources include
Tribally significant plants, animals, and natural resources that are contemporaneously used by Tribal
people; some of these areas may also be documented cultural resources (i.e., TCPs and archaeological
sites). Additionally, Tribal resources include reserved treaty rights including access to usual and
accustomed fishing areas and right to take fish from these areas.
4.9.1 Affected Environment
The affected environment for cultural resources consists of the footprint for Alternatives 2, 3B, and 4,
and surrounding areas that would be affected by construction of the proposed action (Study Area).
Information about the affected environment was obtained from the technical report, Cultural Resources
Inventory Report for BNSF Allentown Truck Re -Route Project EIS (Allen et al. 2024).
4.9.1.1 Cultural Setting
4.9 1 1 1 Precontact Context
The temporal time frames used in the following discussion include regional -specific labels that represent
shifts in subsistence strategies, sociopolitical organization, settlement and land use, and material culture
within the environment of the Puget Sound region, adapted within the broader phase categories used
for many regions across the Pacific Northwest. The phases are divided into three sections based on
archaeological data and are discussed below, as follows: the Paleo-Indian, Archaic, and Pacific periods.
4.9 1 1 2. Paleo-Indian Period (Before 1.)a500 Years BP)
Much of the late Pleistocene terrain in the Puget Sound Region was uninhabitable because of glaciers,
and the lands that were occupied at this time were predominantly coastal reaches. Sites from this
period are rare, as Paleo-Indian populations were small and highly mobile, and much of the land during
this time was covered by glaciers. The earliest occupants in present-day western Washington at this
time are known as Paleo-Indians, who were highly mobile hunter -gatherers living in small groups. These
occupations are characterized by the presence of large, fluted projectile points (Ames and Maschner
1999; Carlson 1990). Paleo-Indians were also thought to be maritime -oriented and therefore occupied
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coastal reaches that are now submerged because of relative sea -level rise following glacial retreat
(Carlson 1990; Dixon 1993; Fedje and Christensen 1999; Fladmark 1979). Ocean levels rose and
submerged many of these coastal sites with the commencement of the warming Holocene epoch.
4.9 1 1 3 Archaic Period (1.2.,500--6,400 Years BP)
Sites from the Archaic period, which dates from 12,500 to 6,400 years BP, are also sparse within the
archaeological record (Ames and Maschner 1999; Carlson 1990). Similar to the Paleo-Indians,
populations during the Archaic period were small, highly mobile, and generally concentrated along the
coast and major waterways. Sea -level changes, erosion, and dense vegetation have obscured much of
the evidence of coastal occupation during this time; however, as the climate continued to warm, glaciers
retreated over larger areas and provided opportunity for inland expansion (Ames and Maschner 1999).
Archaic sites are identifiable by the presence of large, lanceolate projectile points and bifaces, with the
addition of microblades, in Pacific Northwest Archaic tool assemblages (Ames and Maschner 1999).
4.9 1 1 4 Pacific Period (circa 6,400---2.50 Years BP)
The Early Pacific period (6,400 to 3,800 years BP) saw an increase in the use of marine resources as well
as the appearance of human burials in middens and cemeteries, more diversity in subsistence activities,
and the increased use of bone, antler, and ground stone tools. Microblade technology disappeared;
however, ground stone tools (e.g., celts and adze blades) appeared in the toolkit, along with
diversification of chipped -stone tool forms and an increase in ornamental pieces, which appear in
human burial sites and cemeteries. This shift likely represented an expansion of contact and trade with
neighboring groups (Kirk and Daugherty 2007).
The Middle Pacific period (3,800 to 1,500 years BP) is marked by the appearance of long-term
settlements and plank houses, intensification of salmon harvesting, and a variegation in tool form and
style including fishing technologies (e.g., wooden fishing weirs and girdled/drilled net sinkers) (Ames and
Maschner 1999).
The Late Pacific period (1,500 to 250 years BP) saw an increase in the use of larger woodworking tools, a
decline in the use of chipped -stone tools, and an increase in funerary ritual and burial activities.
Stabilizing sea levels during this period mean that the Middle and Late Pacific periods are the most
visible in the coastal archaeological record (Ames and Maschner 1999). The end of the Pacific period is
marked by the introduction of smallpox to the region (Ames and Maschner 1999).
Many of the precontact occupation sites along the Duwamish River have been dated to the Pacific
Period (Campbell 1981). Site 45K100023 (The Duwamish No. 1 site/ ha?apus) is approximately 4.4 miles
downriver from the Study Area. This site was originally recorded in 1975, and subsequent archaeological
investigations documented midden features, hearths, postholes and the remains of structures, and a
limited amount of bone and stone tools (Campbell 1981; Lorenz 1976). Dating of organic material shows
occupation of the site from 2,030 to 226 years BP (Robbins et al. 1998).
4.9 1 1 5 Ethnographic Context and Treaty of Point Elliot
The Study Area is located within the traditional territory of the Duwamish (Dxwdaw?abs) people, a Puget
Salish- or Lushootseed-speaking group that historically inhabited the Duwamish Valley and the shoreline
of Elliot Bay (Cummings 2020; Duwamish Tribal Services Organization 2021). The Duwamish people were
closely tied through intermarriage and a blend of coastal and riverine subsistence strategies with the
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Suquamish people, who occupied the west side of the Puget Sound near Agate Pass (Haeberlin and
Gunther 1930). The Green River and Upper White River (Smulkamish) groups, now known as the
Muckleshoot, traditionally inhabited the Duwamish Valley southeast in areas around modern-day
Auburn including the upper White and Green Rivers (Cummings 2020) (see Appendix E [Allen et al. 2024]
for detailed ethnographic context).
In 1855, the Duwamish, Suquamish, and numerous other Tribes signed the Treaty of Point Elliott with
the federal government. It was signed by Se'alth of the Duwamish and other indigenous leaders selected
to represent their people by the U.S government, including Ts'huahntl, Now-a-chais, and Ha-seh-doo-an,
all of the Duwamish Tribe (Treaty of Point Elliot 1855). Reservations were regionally established
including the Tulalip, Port Madison, Swinomish, and Lummi Reservations, which became the new home
for much of the local indigenous populations. Following the Battle of Seattle in January 1856, the
Muckleshoot Reservation was established for the bands on the White and Green Rivers (Sodt 2004); it
was subsequently enlarged in 1874 to accommodate Native people who had not received a reservation
base (Iverson et al. 2000). The Study Area is located 13.3 miles north of the Muckleshoot Reservation,
and 19.4 miles east of the Port Madison (Suquamish) Reservation.
The Treaty of Point Elliott explicitly reserves hunting and fishing rights on land and in waters within and
outside of the jurisdiction of reservations. Fishing areas that are located off -reservation are referred to
as usual and accustomed (U&A) fishing grounds and stations. The reserved rights of the Tribes to gather,
hunt, and fish are both cultural and economic in nature.
The Duwamish people were assigned to the Port Madison and Muckleshoot reservations in exchange for
ceding 54,000 acres to the U.S government (Celmer 1995, Cummings 2020; Lane 1988). However, some
Duwamish, especially those living upriver, refused to recognize the treaty as legitimate and continued to
live in their traditional lands along the White, Green, and Black Rivers. As early as 1867, the Duwamish
sought to establish a reservation at the confluence of the Black and Cedar Rivers (Celmer 1995;
Cummings 2020; Lane 1988). The Duwamish Tribal Services Organization is still pursuing federal
recognition through the U.S Department of the Interior (Duwamish Tribe 2018b21b). The Duwamish
Longhouse sits on the opposite bank of the Duwamish River from the Study Area and serves as a hub for
the Duwamish people and houses Duwamish Tribal Services Organization, a non-profit dedicated to
promoting Duwamish heritage and ensuring that the needs of Duwamish members are met.
4.9 1 1 6 Historic Context
4.9.1.1.6.1 Allentown
The Allentown neighborhood was platted in the early 1900s by the Allen and the Hillman families
(Reinartz 1991:155-157). By 1940, parcels along the bank of the Duwamish River in both the Hillman and
Allen plats had been developed, and most were further subdivided and improved upon between 1940
and 1964 (NETR 2024). In 1966, the Archie Codiga Bridge was built over the Northern Pacific Railroad
(NP) right-of-way (ROW), and in 1967, 1-5 was completed through Allentown between State Route 900
and the NP ROW. In 1970, Burlington Northern Railroad (BN) widened the railroad ROW and constructed
its Intermodal Facility (BNSF 2010, 2024; NETR 2024). On the west bank of the Duwamish, the peninsula
began to develop into a light industrial area in about 1968. By 1969, a large trucking business had been
constructed along 1-5, and by 1977, the south half of the peninsula had been developed. By 1980,
Tukwila Commerce Park had been completed at the north end of the peninsula (King County 2024f;
237
NETR 2024). Gateway Corporate Center was in development by 1986 and completed by 1991 (Nicola
Wealth 2024). The BECU building was completed in 1990 (King County 2024f).
4.9.1.1.6.2 Seattle Police Athletic Association
The Seattle Police Athletic Association (SPAA) in the north end of Allentown was established during
World War II as a marksmanship and physical fitness facility for Seattle Police Department (SPD) officers
(SPAA 2024). Beginning in 1943, the SPD utilized prisoner labor from the city of Seattle's jail to help with
site construction. In 1947, The SPAA donated 32 acres of land to the City of Seattle for use as a
rehabilitation facility with the agreement that the City would maintain the SPAA's Rifle and Pistol Ranges
located there. An additional 19 acres of land were leased from the NP, and six additional acres were
purchased for a total of 57 acres. The SPD Rehabilitation Program (SPDRP) opened on the SPAA parcels
in August 1948 with 50 inmates (called "patients"), and by 1953, the capacity had been increased to 100.
The patients constructed all the buildings on the property (Burr 1959).
4.9.1.2 Cultural Resources Within the Study Area
There are no listed or designated National Register of Historic Places (NRHP)-, Washington Heritage
Register (WHR), and King County Landmarks Register (KCLR)-historic properties located within,
overlapping, or adjacent to the Study Area.
A district comprised of 13 contributing resources that is potentially eligible to the NRHP, WHR, or KCLR
was identified within the Study Area. Eight of the district's contributing resources are also individually
eligible for the NRHP, WHR, and KCLR. One additional resource within the Study Area that was not
associated with the potential historic district was previously determined eligible for the NRHP by DAHP
and is also eligible for the WHR and KCLR.
There is one historic archaeological site within the Study Area (45K100538 [Columbia and Puget Sound
Railroad]); however, this site was previously determined not eligible for the NRHP. The Columbia and
Puget Sound Railroad Grade intersects proposed Alternative Area 4 as it passes under a bridge along
South 129th Street. The DAHP determined that 45K100538 is not eligible for listing in the NRHP on
January 10, 2021. The Project will not impact this recorded archaeological feature, which does not
require further consideration under the Revised Code of Washington (RCW). There are no additional
known archaeological resources present within the Study Area. However, there is one recently
documented archaeological resource (45K101785 [precontact site]) adjacent to the Alternative 3B Study
Area. Site 45K101785 has not been evaluated for NRHP-eligibility.
The City is not aware of any TCPs within the Study Area. However, the City understands that Duwamish
River is a culturally significant landscape for Tribes. There are known ethnographic place names
associated with oral traditions that intersect the Study Area (Ballard 1929; Waterman et al. 2001). These
place names have not been formally recorded in WISAARD as TCPs. Alternative 2 overlaps an important
part of the southern Puget Sound Salish oral tradition and is considered culturally significant.
According to commenters on the Draft EIS, the segment of the Duwamish River within the Alternative 3B
Study Area is contemporarily used by Tribes and has cultural connections. The City is not aware of
specific Tribal use of the Study Area; however, it is consulting with the Muckleshoot Indian Tribe,
Snoqualmie Indian Tribe, Suquamish Tribe, and Confederated Tribes and Bands of the Yakama Nation
regarding Tribal U&A fishing areas. The City is also coordinating with the Duwamish Tribal Services
Organization regarding its cultural connection of the area.
238
4.9.1..2..1. Seattle Police Athletic Association Historic District
The potentially eligible historic district (SPAA Historic District) is included in Table 4.9-1 and a map of the
district is provided in Figure 4.9-1. The district's proposed boundary encompasses two King County Tax
Parcels (Nos. 0323049099 and 0323049057) as well as portion of two additional parcels (Nos.
0323049030 and 0323049138) and is located within Alternative 2. Historic built -environment resources
surveyed for this analysis are listed in Table 4.9-1 by Property ID and depicted in Figure 4.9-1.
Alternative 2 is anticipated to impact the eligible historic district and the eight individually eligible
properties within its boundary.
The eligible SPAA Historic District contains buildings, structures, and landscapes associated with the
SPAA, the SPDRP, and Seattle Police Department Alcoholics Rehabilitation Farm (SPDARF) (see Appendix
E [Allen et al. 2024] for historic context of the SPDRP and SPDARF). The potential Historic District is
eligible for listing in the NRHP under Criterion A in the Areas of Social History and Recreation for its
association with the SPAA, SPDRP, and SPDARF, and under Criterion C in the area of Architecture as a
distinguishable cluster of post -World War II buildings and structures associated with the SPDRP. Under
Criterion A, the character -defining features of the site include the buildings and structures constructed
by SPD inmates, shooting ranges and training areas, the central lawn with surrounding driveway, and
the general site layout. The potential district's period of significance is 1943-1976, corresponding with
the beginning of SPAA's ownership of the site (1943) and the date the last historic -age building was
completed (1976). Under Criterion C, the character -defining features of the district are the buildings,
structures, and landscapes constructed during the SPDRP and SPDARF era including the Picnic Shelter
(1947), SPDRP Dormitory (1948), Duplex (1950), the Pavilion (1953), the Pistol Range and Sheds (ca.
1959), and the Range Office (1960), as well as the central lawn, driveway, general site plan, and
circulation pattern between the buildings. Under Criterion C, the period of significance is 1943-1960,
corresponding with the dates of construction of the first and last SPDRP/SPDARF buildings. The potential
SPAA Facility Historic District is also eligible for listing in the WHR and KCLR.
239
Historic District Status
Recommended eligible for the NRHP,
WHR, and KCLR.
Contributes to SPAA Facility Historic
District
Contributes to SPAA Facility Historic
District
Contributes to SPAA Facility Historic
District
Contributes to SPAA Facility Historic
District
Contributes to SPAA Facility Historic
District
Contributes to SPAA Facility Historic
District.
Contributes to SPAA Facility Historic
District
Contributes to SPAA Facility Historic
District
Contributes to SPAA Facility Historic
District
Contributes to SPAA Facility Historic
District
Contributes to SPAA Facility Historic
District
Contributes to SPAA Facility Historic
District
Contributes to SPAA Facility Historic
District
Note: DAHP has not made determinations of eligibility for these 13 historic built -environment resources.
Register Listing (Individual Level)
a
z
Not Individually Eligible for the NRHP,
WHR, or KCLR
Assumed Individually Eligible for the
NRHP, WHR, and KCLR
Not Individually Eligible for the NRHP,
WHR, or KCLR
Not Individually Eligible for the NRHP,
WHR, or KCLR
Individually Eligible for the NRHP,
WHR, and KCLR
Assumed Individually Eligible for the
NRHP, WHR, and KCLR
Individually Eligible for the NRHP,
WHR, and KCLR
Individually Eligible for the NRHP,
WHR, and KCLR
Individually Eligible for the NRHP,
WHR, and KCLR
Not Individually Eligible for the NRHP,
WHR, and KCLR
Not Individually Eligible for the NRHP,
WHR, and KCLR
Individually Eligible for the NRHP,
WHR, and KCLR
Not Individually Eligible for the NRHP,
WHR, and KCLR
4,
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Ca. 1943-76
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Historic Name
Seattle Police Athletic Association
(SPAA) Historic District
Garage -
Seattle Police Athletic Association
Seattle Police Department
Rehabilitation Program Dormitory-
SPAA Facility
K-9 Building -
Seattle Police Athletic Association
Pistol Range Sheds -
Seattle Police Athletic Association
Duplex -
Seattle Police Athletic Association
Classroom -
Seattle Police Athletic Association
Picnic Shelter -
Seattle Police Athletic Association
Range Office -
Seattle Police Athletic Association
Pavilion -
Seattle Police Athletic Association
Rifle Range Shed -
Seattle Police Athletic Association
Combat Range No. 2 Range Shed -
Seattle Police Athletic Association
Munitions Storage Shed -
Seattle Police Athletic Association
Gate House -
Seattle Police Athletic Association
Property
ID
a
z
734859
734860
734861
734863
734864
734865
734867
734868
734870
734871
734873
734874
734875
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to
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4.9.1.2..2. Seattle & Walla Walla Railroad/Puget Sound Shore Railroad Company/Seattle, Lake Shore &
Eastern Railroad/Northern Pacific Railway Black River -Junction to the Lake Washington Ship
Canal
One NRHP-, WHR-, and KCLR- eligible resource not affiliated with the historic district (Seattle & Walla
Walla Railroad/Puget Sound Shore Railroad Company/Seattle, Lake Shore & Eastern Railroad/Northern
Pacific Railway Black River Junction to the Lake Washington Ship Canal [S&WW/PSS/SLS&E/NP]) is
shown in Table 4.9-2 and depicted in Figure 4.9-2. This historic property was previously determined
eligible for the NRHP by DAHP in 2017. It is located adjacent to Alternatives 2, 3B, 4, and the No Action
Alternative; however, it is not anticipated to be permanently impacted by the Project.
Table 4.9-2. Individually eligible historic property not associated with the SPAA Historic District.
Property ID
Historic Name
Year
Built
Register Listing
(Individual Level)
Historic District
Status
708606
Seattle & Walla Walla Railroad/Puget
Sound Shore Railroad
Company/Seattle, Lake Shore &
Eastern Railroad/Northern Pacific
Railway Black River Junction to the
Lake Washington Ship Canal
(S&WW/PSS/SLS&E/NP)
Ca.
1883-
1905
Previously
Determined
Individually Eligible
for the NRHP.
Recommended
eligible for the WHR
and KCLR.
N/A
242
a
H., H., 01,11SISSIIIC
4.9.2 Relevant Plans, Policies, and Regulations
The Project is within King County and must comply with the King County Code (KCC), as well as the RCW.
Chapter 20.62 of the KCC outlines procedures and regulations for the identification and protection of
historic and archaeological resources significant to the history of King County. Historic or archaeological
resources that are of significance to King County are defined under KCC 20.62.040, and the procedures
for nomination of locally significant resources to the King County Landmarks Register (KCLR) are defined
under KCC 20.62.050. In accordance with KCC 20.62.150, any resources identified in the King County
Historic Resource Inventory (KCHRI) shall not be altered, demolished, or relocated as a consequence of
any development proposal without prior review from the appointed King County landmarks commission.
Precontact archaeological sites and historic archaeological resources are protected by several
Washington State regulations on both public and private lands. RCW 27.44 (Indian Graves and Records)
and RCW 27.53 (Archaeological Sites and Resources) require that a person obtain a permit from DAHP
before excavating, removing, or altering Native American human remains or archaeological resources in
Washington. Chapters 25-48 of the Washington Administrative Code outline the requirements of the
Archaeological Excavation and Removal Permit. Failure to obtain a permit is punishable by civil fines and
penalties under RCW 27.53.095 and criminal prosecution under RCW 27.53.090.
4.9.3 Impacts
4.9.3.1 Methodology
Information about identification and evaluation methods is described in the technical report, Cultural
Resources Inventory Report for BNSFAIIentown Truck Re -Route Project EIS (Appendix E; Allen et al.
2024). The City's consultant, HDR, performed cultural resources background review and a
reconnaissance -level historic built -environment survey within the Study Area (Allen, et al. 2024). The
cultural resources background review was performed using the Washington Information System for
Architectural and Archeological Records Data (WISAARD), historic maps and imagery, and publicly
available documents to assess the potential for archaeological and ethnographic resources, TCPs, and
known place names in the Study Area. There is one previously recorded historic archaeological site
within the Study Area (45K100538); however, it was previously not eligible for the NRHP. There are no
additional archaeological resources within the Study Area, and thus, no impacts were assessed for these
resources.
HDR performed a reconnaissance -level historic built -environment survey of Alternatives 2, 3B, and 4 in
accordance with the Washington State Standards for Cultural Resources Reporting (DAHP 2023). The
reconnaissance -level historic built -environment survey involved extensive photographic and written
documentation of all resources 35 years old and older within the proposed Study Area. Prior to
fieldwork, HDR conducted research through the King County Assessor's online database and
HistoricAerials.com to identify all parcels within the Study Area that contain historic -age built -
environment resources.
Adverse impacts to cultural resources occur when a project action diminishes the characteristics of a
cultural resource that qualify it for listing the NRHP, WHR, and/or KCLR. The integrity of a cultural
resource is assessed through the characteristics that define its location, design, setting, materials,
workmanship, feeling, and association. Most of the characteristics of these seven qualities must be
244
present for a resource to convey its significance. Project effects are based on the potential for significant
impacts to a cultural resource's integrity and divided into three categories:
• No effect: no change to the integrity of a resource.
• Less -than -significant: temporary or reversible impacts that may diminish a resource's integrity,
but the resource retains the characteristics that qualify it for listing in the NRHP, WHR, and
KCLR, and do not diminish the recourse's ability to convey its significance.
• Significant: permanent direct or indirect effects, per 36 CFR Part 800.5, that diminish the
characteristics that qualify it for listing in the NRHP, WHR, and KCLR and its integrity such that it
is no longer able to convey its significance.
Impacts to cultural resources could occur during both construction and operation. These impacts are
defined by their effect on a resources' integrity:
• Minor impacts are those caused by temporary project -related construction and operation
activities such as increase in noise and vibration, increased dust, increased traffic or traffic
congestion, temporary changes to access, and the presence of construction equipment. These
impacts are temporary and minimal and do not permanently diminish the integrity of a
resource.
• Moderate impacts are those that result in diminished integrity and may or may not diminish the
resource's ability to convey its significance and its eligibility for the NRHP, WHR, and KCLR. These
could include alterations to a resource that diminish its integrity such that it may no longer be
individually eligible for the NRHP, WHR, and KCLR, but retains enough integrity to contribute to
a historic district.
• Significant impacts may include destruction, damage to, or alteration of a resource; removal of a
resource from its original location; changes to the use or physical features of a resource; and the
introduction of permanent visual, atmospheric, or audible elements that permanently diminish
the integrity of the resource such that it is no longer able to convey its significance.
The City assessed impacts to Tribal resources using publicly available information and in consultation
with the Muckleshoot Indian Tribe, Snoqualmie Indian Tribe, Suquamish Tribe, and Confederated Tribes
and Bands of the Yakama Nation. The City is also coordinating with the Duwamish Tribal Services
Organization regarding potential impacts. Impacts were analyzed based on the following and are also
described in Section 4.11 as well:
• No impact: no change to a Tribal resource, U&A fishing grounds and stations, and access to U&A
areas.
• Minor and Moderate: temporary or reversible impacts to a Tribal resource; temporary access
change or detour to U&A areas.
• Significant: permanent impact to a Tribal resource; permanent change or lack of access to U&A
access.
4.9.3.2 Impacts Analysis
Table 4.9-3 lists the documented archaeological resources and historic built -environment resources
(both eligible and non -eligible) that would be impacted in each proposed Alternative Study Area. The
City is not aware of any TCPs within the Study Area. However, Alternative 2 overlaps an important part
245
of the southern Puget Sound Salish oral tradition and is considered culturally significant. Furthermore,
Alternative 3B Study Area is contemporarily used by Tribes and has cultural connections.
A total of 37 historic -age built -environment resources were surveyed. One of those was previously
determined eligible for the NRHP by DAHP and fourteen resources are recommended eligible for the
NRHP, WHR, and KCLR, and thus, are considered significant for the purposes of this EIS. Impacts were
assessed for those 15 historic properties. Archaeological survey could not be performed due to lack of
access to private property; however, background review indicates only a single historic archaeological
site within Alternative 4. This site was previously determined not eligible for the NRHP and as such, does
not require assessment for Project impacts. There are no additional known archaeological resources
present within the Study Area. Although there is a precontact site adjacent to Alternative 3B, it would be
avoided by construction and operations.
Alternative Study Area 2 has a very high likelihood to impact multiple historic built -environment
resources that are either eligible for the NRHP individually or contribute to the potential SPAA Historic
District. While both Alternative Study Area 3B and 4 will impact the S&WW/PSS/SLS&E/NP (Property ID
708606, these impacts would be temporary and not have the potential to impact the character -defining
features of the railway segment.
246
0
10
10
10
0
C
10
Present Non- Eligible Historic Built -
Environment Resources
• Boeing Access Road Bridge
• West Boeing Access Road Bridge
• 10836 East Marginal Way South
• BNSF South Seattle Intermodal Facility Historic
District
• Combat Range No. 1— SPAA Facility
• Butler Building — SPAA Facility
• SPAA Office — SPAA Facility
• BNSF South Seattle Intermodal Facility Historic
District
• Gateway Corporate Center Historic District
• UPRR-OWR&N Segment
• Green River Trail
• 13123 Interurban Avenue
• Building 5 — Gateway Corporate Center; 12806
Gateway Drive South
• Building 6 — Gateway Corporate Center; 12761
Gateway Drive South
• State Route 900
• UPRR-OWR&N Segment
• Archie Codiga Bridge (South 129th Street Bridge)
• 5510 South 129th Street
• 12529 51st Place South
• 12537 51st Place South
Present Eligible Historic Built -Environment
Resources
• Seattle & Walla Walla Railroad/Puget Sound Shore
Railroad Company/Seattle, Lake Shore & Eastern
Railroad/Northern Pacific Railway Black River
Junction to the Lake Washington Ship Canal
(S&WW/PSS/SLS&E/NP)
• SPAA Facility Historic District
• Garage — SPAA Facility
• Seattle Police Department Rehabilitation Program
Dormitory — SPAA Facility
• K-9 Building — SPAA Facility
• Pistol Range Sheds — SPAA Facility
• Duplex — SPAA Facility
• Classroom — SPAA Facility
• Picnic Shelter — SPAA Facility
• Range Office — SPAA Facility
• Pavilion — SPAA Facility
• Rifle Range Shed — SPAA Facility
• Combat Range No. 2 Range Shed — SPAA Facility
• Munitions Storage Shed — SPAA Facility
• Gate House — SPAA Facility
• Seattle & Walla Walla Railroad/Puget Sound Shore
Railroad Company/Seattle, Lake Shore & Eastern
Railroad/Northern Pacific Railway Black River
Junction to the Lake Washington Ship Canal
• Seattle & Walla Walla Railroad/Puget Sound Shore
Railroad Company/Seattle, Lake Shore & Eastern
Railroad/Northern Pacific Railway Black River
Junction to the Lake Washington Ship Canal
(S&WW/PSS/SLS&E/NP)
Present
Archaeological
Resources
O
Q
T
O
= O
O
=
O O
Z o
O
Q
C
o
O
Y
O
E
O
c
=
O
Z
Columbia and
Puget Sound
Railroad Grade
(45KI00538; not
eligible)'
Present Tribal
Resources/
TCP
O
O
O
0)
O
T
12
O
2
U co
Z'
O
O
O_ O
n
E =
O
O =
O H
None known
Probability
0
O)
i
O
E
O
2J
0
Alternative
Study Area
N
CO
V
i Site 45KI00538 was previously determined not eligible for listing in the NRHP and therefore does not require further consideration under the RCW.
4.9.3.2..1. Construction Impacts
Construction activities could impact archaeological resources, TCPs, or Tribal resources that may be
present within the Study Area through physical damage, burial, relocation, vibration, noise, traffic
congestion, increased traffic, or viewshed changes. However, there is only a single historic
archaeological site within the Alternative 4 Study Area, which was previously determined not eligible for
the NRHP and as such, does not require assessment for Project impacts. There are no additional known
archaeological resources present within any of the alternatives Study Area. Accordingly, none of the
alternatives would impact known archaeological resources.
The City is not aware of any documented TCPs within the Study Area. However, Alternative 2 overlaps a
Tribal resource and the Alternative 3B Study Area is contemporarily used by Tribes and has cultural
connections. Short-term construction activities would result in temporary and minor to moderate
impacts on these Tribal resources due to noise, dust, traffic congestions, increased truck traffic, and
viewshed changes. Long-term construction impacts to wetlands would be minor to moderate depending
on the nature of the impact (i.e., filling, dewatering, spill, etc.). Impacts associated with plants and
animals that provide important subsistence and medicinal resources to Tribal people could potentially
result in minor to significant impacts on Tribes; however, these impacts would be mitigated through
BMPs and mitigation, as described above in Section 4.3 and below in Section 4.9.4. There would be no
restrictions to accessing U&A fishing grounds.
Alternative 4 would result in temporary and minor impacts to nearby Tribal resources due to increased
truck traffic and traffic congestion, as well as potential sedimentation to Stream 1, which is a potentially
fish -bearing stream that has an unknown outlet. Alternative 4 would not result in access restrictions on
U&A fishing grounds.
Short-term construction impacts include a temporary increase in noise and vibration, as well as more
truck traffic, traffic congestion, temporary changes to access, and increased dust in the setting of
historic built environment resources that are eligible for the NRHP (i.e., historic properties). The
presence of construction equipment could result in short-term, minor, visual changes to the setting of
historic properties. These construction activities would likely result in minor impacts to the eligible
segment of S&WW/PSS/SLS&E/NP railroad. Construction activities associated with Alternatives 2, 3B,
and 4 in the vicinity of the segment and the presence of Project -related construction equipment within
the BNSF ROW could result in short-term, minor, visual changes to its setting.
Project activities would not cause physical destruction or damage to any part of the segment, and no
alterations would occur to the segment that would be inconsistent with the Secretary of the Interior's
standards for the treatment of historic properties (36 CFR Part 68) and applicable guidelines. No part of
the segment would be removed from its current location, and no changes would occur to the character
of the segment's use or to physical features within the segment's setting that contribute to its historic
significance. No visual, atmospheric, or audible elements would be introduced that would diminish the
integrity of the segment's significant historic features. No neglect would occur to the segment, and the
segment's ownership would not be impacted. None of the project activities associated with Alternatives
2, 3B, and 4 would have the potential to impact the character -defining features of the segment. In
addition, all impacts related to construction activity would be temporary and minimal.
248
4.9.3.2..2. Operations Impacts
There is a single historic archaeological site within Alternative 4, which was previously determined not
eligible for the NRHP and as such, does not require assessment for Project impacts. There are no
additional known archaeological resources in the Study Area. Accordingly, none of the alternatives
would impact known archaeological resources.
The City is not aware of any documented TCPs within the Study Area. However, Alternatives 2 and 3B
overlap Tribal resources, and Alternative 4 is in proximity to these resources. As described under Section
4.3.4.2.2.1 (Wetlands), there would be mitigated significant impacts to wetlands due to filling and
increase of impervious surfaces, and potentially to vegetation due to shading created by the elevated
structure. Impacts associated with plants and animals that provide important subsistence and medicinal
resources to Tribal peoples could potentially result in minor to moderate impacts on Tribes. If
Alternative 3B is selected, a vegetated study would be necessary, which would include consideration of
tribally significant plant species. Additionally, Alternative 4 would intersect Stream 1 which has the
potential for anadromous fish, but in -stream habitat alteration and fish passage are not expected to be
impacted for this alternative. If a spill were to occur during operation under any action alternative, it
could result in minor to moderate impacts to Tribal resources and U&A areas, as described under
Section 4.11.4.2.
Long-term impacts relating to project operation and maintenance will be similar to the short-term
impacts to historic built environment resources on a more permanent basis. These include an increase in
noise and vibration, as well as more truck traffic, traffic congestion, temporary changes to access, and
increased dust. These would likely result in permanent minor impacts to the eligible segment of
S&WW/PSS/SLS&E/NP. Operation and maintenance activities associated with Alternatives 2, 3B, and 4
in the vicinity of the segment and the presence of Project -related construction equipment within the
BNSF ROW could result in permanent, minor, visual changes to its setting.
Project activities would not cause physical destruction or damage to any part of the segment, and no
alterations would occur to the segment that would be inconsistent with the Secretary of the Interior's
standards for the treatment of historic properties (36 CFR Part 68) and applicable guidelines. No part of
the segment would be removed from its current location, and no changes would occur to the character
of the segment's use or to physical features within the segment's setting that contribute to its historic
significance. No visual, atmospheric, or audible elements would be introduced that would diminish the
integrity of the segment's significant historic features. No neglect would occur to the segment, and the
segment's ownership would not be impacted. None of the project activities associated with Alternatives
2, 3B, and 4 would have the potential to impact the character -defining features of the segment.
4.9.4 Mitigation Measures
Based on the background review and survey results presented in the technical report (Appendix E; Allen,
et al. 2024), the three proposed alternative areas have variable potential for containing archaeological
resources and historic built -environment resources. There are no known TCPs within any of the
proposed alternatives. However, Alternatives 2 and 3B overlap Tribal resources and Alternative 4 is in
proximity to these resources.
Alternative 2 (as currently described) would result in probable significant adverse impacts to the SPAA
Historic District and its contributing resources that are recommended eligible to the NRHP, WHR, and
249
KCLR. HDR recommends that Alternative 2 be avoided. If Alternative 2 is selected, additional
documentation, evaluation, and consultation with DAHP, the King County Historic Preservation Program,
and affected Indian Tribes to mitigate significant adverse impacts will be required.
The following additional measures implemented during construction and operation may help avoid,
minimize, reduce, or monitor for the potential for impacts identified in impacts analysis (WAC 197-11-
768):
• If Alternative 2 is selected, perform an intensive -level survey of the potential SPAA Historic
District to determine the location of cultural resources relative to the specific areas of ground
disturbance and building, structure, and landscape alteration and demolition.
• Conduct an archaeological survey of the selected Alternative area prior to construction.
• Consult with Indian Tribes regarding impacts to TCPs, known place names, Tribal resources, and
U&A fishing grounds for the selected alternative. Consultation to include the development of
appropriate mitigation measures.
• Design and site construction to avoid significant impacts to cultural and Tribal resources,
including access to U&A fishing grounds.
• Include Tribal and archaeological monitors during Project construction and develop a
Monitoring and Inadvertent Discovery Plan (MIDP) prior to construction.
4.9.5 Significant Unavoidable Adverse Impacts
Significant unavoidable adverse impacts are those that diminish a cultural resource's integrity of
location, design, setting, materials, workmanship, feeling, and association such that it is no longer able
to convey its significance and no longer eligible for the NRHP, WHR, and/or KCRL. This could be as a
result of alteration, demolition, removal, or change -in -use.
Alternative 2 has a high probability for significant unavoidable adverse impacts as the potential SPAA
Historic District is located within the proposed area of disturbance. According to the proposed project
description for Alternative 2, most of the northern parcel would be graded and leveled to accommodate
construction of the BNSF Intermodal Facility's entrance gates, laydown yard, chassis storage, and trailer
storage, and to allow large vehicles to maneuver throughout the site. The proposed project description
includes demolition and new, permanent construction within the northern parcel; however, plans do
not specifically depict where features would be placed within the northern parcel, and specific areas for
demolition and new construction within the northern parcel have not been identified at this stage of
high-level conceptual modeling. The area for disturbance within the northern parcel was delineated
based on the square footage needs of the existing BNSF facilities that would be moved to the site and
could potentially be expanded or redesigned. The southwestern SPAA parcel, containing the Duplex,
Picnic Shelter, Pavilion, and Range Office is not currently planned to have any physical disturbance.
Based on the project description, proposed Project activities within the northern parcel could cause
physical destruction or damage to the potential SPAA Historic District's buildings and structures, and
alterations could occur to the potential SPAA Historic District that would be inconsistent with the SOI's
standards for the treatment of historic properties (36 CFR Part 68) and applicable guidelines. The
potential SPAA Historic District's buildings and structures within and adjacent to the proposed
disturbance area could be removed from their current location, and changes could occur to the
character of the potential SPAA Historic District's use or to physical features within the SPAA Facility's
250
setting that contribute to its historic significance. Visual, atmospheric, or audible elements could be
introduced that would diminish the integrity of the potential SPAA Historic District's significant historic
features both within and adjacent to the proposed disturbance area. Changes to the potential SPAA
Historic District's ownership could also occur.
In addition, proposed Project -related construction activities in the vicinity of the potential SPAA Historic
District could result in temporary increases in noise and vibration, as well as more truck traffic, traffic
congestion, temporary changes to access, and increased dust. The presence of Project -related
construction equipment within the potential SPAA Historic District parcels could result in short-term,
minor, visual changes to the setting.
Based on the project description, proposed Alternative 2 activities within the SPAA parcels would have
the potential to impact the character -defining features of the potential SPAA Historic District and its
individual historic properties.
251
4.10 Noise
4.10.1 Affected Environment
4.10.1.1 Characteristics of Noise
Sound is made up of tiny fluctuations in air pressure and is characterized by its amplitude (how loud it
is), frequency (or pitch), and duration. Within the range of human hearing, sound can vary in amplitude
by over one million units. Therefore, a logarithmic scale, known as the decibel (dB) scale, is used to
quantify sound intensity and to compress the scale to a more manageable range. Noise is simply defined
as unwanted sound; the terms noise and sound are often used interchangeably. Noise of sufficient
strength might pose health concerns such as hearing loss or sleep disturbances. Noise impacts are
somewhat variable and often depend on land uses. For example, areas where people sleep tend to be
more sensitive to noise compared with places where people congregate during the day, such as parks or
schools. This section describes basic acoustical concepts; how noise is regulated at the municipal,
county, and state level; and existing noise levels in the study area. This section also includes estimates of
noise associated with the proposed project alternatives and a discussion of appropriate mitigation to
reduce noise impacts.
The human ear does not hear all frequencies equally. In fact, the human hearing organs of the inner ear
de-emphasize low and very high frequencies. The A -weighting scale is the most common weighting scale
used to reflect this selective sensitivity of human hearing. It puts more emphasis or "weight" on the
frequencies we hear efficiently, and less weight on frequencies we do not hear efficiently. A -weighted
decibels are noted using the abbreviation dBA. Table 4.10-1 lists noise levels for typical sources.
Table 4.10-1 Typical Source Noise Levels
Sound Pressure
Level, dBA
Typical Sources
100
Jet flyover at 1000 feet
90
Gas lawn mower at 3 feet
85
Food blender at 5 feet
75
Shouting at 3 feet
70
Vacuum Cleaner at 10 feet
60
Conversational speech
50
Quiet urban daytime
40
Quiet urban nighttime
35
Quiet suburban nighttime
30
Quiet bedroom at night
20
Quiet rural nighttime
0
Approximate threshold of hearing
Source: MPCA 2015, adapted
Most sounds are made up of a wide range of frequencies and are termed broadband sounds. Sounds
that are focused within a particular frequency range are tonal sounds. Sound sources can be constant or
time varying. Environmental sound levels are often expressed over periods of time, thereby allowing
252
time -varying signals to be represented by sound levels averaged over intervals (for example, a one -hour
period). One metric used to describe environmental sound is the equivalent average sound level (Leq),
which represents a constant sound that, over the specified time period, has the same acoustic energy as
the time -varying signal. It is a mean average noise level over a one -hour period.
4.10.1.2 Noise Study Area
The BNSF South Seattle Hub (SSH) in the Allentown neighborhood of Tukwila, Washington is an
important economic link to the Puget Sound Region. It serves as an inland port, providing domestic
intermodal transloading between truck and rail. In order to improve livability and safety in Allentown
without compromising the operations of the BNSF intermodal facility, the City of Tukwila (City) is
evaluating new potential truck access routes to the facility.
The City is the lead agency overseeing the preparation of an Environmental Impact Statement (EIS)
under the State Environmental Policy Act (SEPA) for the proposed Allentown Truck Reroute Project
(Project). The existing truck route and No Action Alternative, in addition to three proposed route
alternatives are analyzed in the EIS to determine potential impacts on the built and natural
environment. The Alternatives were brought forth through the scoping process and present changes
that minimize truck traffic interface with residential and recreational areas. These routes are shown in
Figure 4.10-1 below.
Noise related to operation of the proposed project will originate from trucks operating along the
selected new route. The distribution of truck operations within the existing facility may change due to
the Project; however, the quantity of trucks operating within the facility will not change as a result of
the Project.
The noise study area for construction and operational noise is an area extending 500 feet from the No -
Action truck route and the route alternatives, as shown in Figure 4.10-2 through Figure 4.10-6. This
corresponds to the typical study area extents of a Federal Highway Administration (FHWA) traffic noise
study.
253
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4.10.1.3 Existing Noise Environment
The dominant features of the soundscape in the study area are noises from transportation corridors
close to the area. All project alternatives are near Interstate 5, an eight -lane highway. The existing truck
route is near State Route 599, a four -lane divided highway. The existing BNSF intermodal facility and the
railway adjacent to it are also sources of noise in the area. Near the north end of the BNSF intermodal
facility, the Seattle Police Athletic Association (SPAA) operates a shooting range that is a source of noise
for residents along South 113th Street during its daily operating hours of 9:00 AM — 4:30 PM.
Noise -sensitive land uses along the existing truck route include residences along South 124th Street and
the Tukwila Community Center. Trucks accessing the BNSF intermodal facility along this route comprise
a large proportion of the truck traffic in this area, and thus represent a large proportion of the noise that
residents near the route are exposed to.
Noise -sensitive land uses near Alternative 2 include Duwamish Hill Preserve and residences along South
113th Street. Noise -sensitive land uses along Alternatives 3B and 4 include residences along 51st Place
South and Codiga Farm Park.
Table 4.10-2 contains typical A -weighted noise levels for residential areas.
Table 4.10-2 Typical Residential Noise Levels
Residential Land Use
Category
Daytime Sound
Pressure Level, dBA
Nighttime Sound Pressure Level, dBA
Very noisy urban
66
58
Noisy urban
61
54
Urban and noisy
suburban
55
49
Quiet urban and
normal suburban
50
44
Quiet suburban
45
39
Very quiet suburban
and rural
40
34
Source: ANSI/ASA 2013
4.10.2 Relevant Plans Policies and Regulations
Noise is addressed in the City of Tukwila and King County noise ordinances, and the Washington
Administrative Code (WAC).
4.10. 2.1 Washington Administrative Code - Chapter 173-60
The State of Washington has a robust environmental noise control program. It regulates maximum
allowable noise levels using different limits for receiving lands of differing noise sensitivity. Chapter 173-
60-040 of the WAC establishes different noise limits, depending upon the environmental designation for
noise abatement (EDNA) or area or zone (environment) of the property from which the noise originates
and the property where the noise is received.
260
EDNA Class A represents lands where people reside and sleep. Typically, Class A EDNA includes the
following types of property used for human habitation: residential, multiple family living
accommodations, recreational and entertainment (such as camps, parks, camping facilities, and resorts),
and community service (such as orphanages, homes for the aged, hospitals, and health and correctional
facilities).
EDNA Class B represents lands with uses requiring protection against noise interference with speech.
Typically Class B EDNA includes the following types of property: commercial living accommodations;
commercial dining establishments; motor vehicle services; retail services; banks and office buildings;
miscellaneous commercial services properties not used for human habitation; recreation and
entertainment property not used for human habitation (such as theaters, stadiums, fairgrounds, and
amusement parks); and community services property not used for human habitation (such as
educational, religious, governmental, cultural, and recreational facilities).
EDNA Class C represents lands with economic activities of such a nature that higher noise levels than
experienced in other areas is normally anticipated. People working in these areas are normally covered
by noise control regulations of the department of labor and industries. Uses typical of Class A EDNA are
generally not permitted within such areas. Typically, Class C EDNA includes the following types of
property: storage, warehouse, and distribution facilities; industrial property used for the production and
fabrication of durable and nondurable man-made goods; and agricultural and silvicultural property used
to produce crops, wood products, or livestock.
Under the WAC, no person may cause or permit noise that exceeds the maximum permissible noise
levels listed in Table 4.10-3 to intrude into the property of another person. Between 10:00 PM and
7:00 AM, the noise limitations presented in Table 4.10-3 are reduced by 10 dBA for receiving property
within Class A EDNAs. At any hour of the day or night, those noise limitations may be exceeded for any
receiving property by no more than:
• 5 dBA for a total of 15 minutes in any one -hour period; or
• 10 dBA for a total of 5 minutes in any one -hour period; or
• 15 dBA for a total of 1.5 minutes in any one -hour period.
Table 4.10 .3 Washington Administrative Code Noise Limits
EDNA of Noise Source
EDNA of Receiving Property
Class A
Class B
Class C
Class A
55 dBA
57 dBA
60 dBA
Class B
57 dBA
60 dBA
65 dBA
Class C
60 dBA
65 dBA
70 dBA
Source: Washington Administrative Code 173-60-040
Noise emissions from motor vehicles on public highways are exempt4. Therefore, only noise from
vehicles using non-public sections of the proposed roadways would be subject to these noise limits. The
4 WAC 173-62-020 defines "public highway" as the entire width between the boundary lines of every way publicly
maintained by the department of highways or any county or city when any part thereof is generally open to the
use of the public for purposes of vehicular travel as a matter of right.
261
assessment of potential project impacts on noise considers the study area to be an industrial land use
(EDNA Class C), and surrounding noise -sensitive land uses are primarily residential neighborhoods
(EDNA Class A). Therefore, the maximum allowable operational noise level at residences surrounding
the study area is 50 dBA during the night and 60 dBA during the day. That limit can be exceeded for brief
durations as explained above.
Construction noise is specifically addressed and is exempt from regulation unless it occurs during
nighttime hours (10:00 PM to 7:00 AM), when it is subject to the numeric limits. If construction occurs
during nighttime hours, it is subject to the maximum permissible noise levels in Chapter 173-60-040. The
assessment of potential project impacts on noise considers the study area to be an industrial land use
(EDNA Class C) adjacent to a residential neighborhood (EDNA Class A). Therefore, the maximum
allowable nighttime construction noise level at residences surrounding the study area is 50 dBA (60 dBA
reduced by 10 dB, as explained in the preceding paragraph for nighttime hours). That limit can be
exceeded for brief durations as explained above.
4.10.2.2 King County Code — Chapter 17.8E Noise
The King County Code (KCC) Chapter 12.86 regulates maximum allowable noise levels using different
limits for receiving lands of differing noise sensitivity. These limits are shown in Table 4.10-4. Between
10:00 PM and 7:00 AM on weekdays and between 10:00 PM and 9:00 AM on weekends, the noise
limitations presented in Table 4.10-4 are reduced by 10 dBA for rural and residential receiving
properties. These limits are based on the Leq during a specified measurement interval. The maximum
sound level (Lmax) during this interval may not exceed the specified limits by more than 15 dBA.
Table 4.10-4 King County Code Noise Limits
Sound Source District
Receiving Property District
Rural
Residential
Commercial
Industrial
Rural
49 dBA
52 dBA
55 dBA
57 dBA
Residential
52 dBA
55 dBA
57 dBA
60 dBA
Commercial
55 dBA
57 dBA
60 dBA
65 dBA
Industrial
57 dBA
60 dBA
65 dBA
70 dBA
Source: King County Code 12.86.110
Noise emissions from motor vehicles on public highways are exempt.' Therefore, only noise from
vehicles using non-public sections of the proposed roadways would be subject to these limits. The
assessment of potential project impacts on noise considers the study area to be an industrial land use,
with nearby residential areas. Therefore, the maximum allowable operational noise level at residences
surrounding the study area is 50 dBA during the night and 60 dBA during the day. The maximum
allowable Lmax from individual vehicles on the non-public routes would be 65 dBA during the night and
75 dBA during the day.
Per KCC section 12.86.520, "normal and usual" construction noise is restricted to specified operation
times based on equipment type but is exempt from sound level requirements. Operating hours for
heavy equipment are between 7:00 AM and 7:00 PM on weekdays and between 9:00 AM and 7:00 PM
5 KCC 12.86.030 (P) defines "public highway" as the entire width between the boundary lines of every way publicly
maintained by the Washington state Department of Transportation or any county or city when any part thereof is
generally open to the use of the public for purposes of vehicular travel as a matter of right
262
on weekends. Operating hours for impact -noise -generating equipment are between 8:00 AM and 5:00
PM on weekdays and between 9:00 AM and 5:00 PM on weekends. Operating hours for all other
construction activities are between 7:00 AM and 10:00 PM on weekdays and between 9:00 AM and 8:00
PM on weekends.
4.10.2.3 City of Tukwila Municipal Code — Chapter 8.22
The City of Tukwila regulates environmental noise using the limits shown in Table 4.10-5. These are
essentially the same as the limits in WAC 173-60-040. The same specifications as in WAC apply regarding
durations of exceedances. Daytime is defined as 7:00 AM-10:00 PM Monday through Friday, and
8:00 AM-10:00 PM on Saturday, Sunday, and State -recognized holidays.
Table 4.10-5 City of Tukwila Municipal Code Noise Limits
Sound Source District
Receiving Property District
Residential,
Daytime
Residential,
Nighttime
Commercial
Industrial
Residential
55 dBA
45 dBA
57 dBA
60 dBA
Commercial
57 dBA
47 dBA
60 dBA
65 dBA
Industrial
60 dBA
50 dBA
65 dBA
70 dBA
Source: Tukwila Municipal Code 8.22.050
The code also specifies that no sound is permitted that is plainly audible on a receiving property in a
residential district at a distance of at least 50 feet from the sound -producing source, including sounds
created by any motor vehicle operated off public highways6. This would apply to vehicle noise on non -
publicly accessible Project roadways. Noise from motor vehicles on public highways is exempt from the
above limits.
The operation of equipment or facilities of surface carriers engaged in commerce by railroad is exempt.
Construction noise is exempt during daytime hours as defined above.
4.10.3 Impacts
4.10.3.1 Methodology
Noise impacts are evaluated using the definitions listed in Table 4.10-6.
6 TMC Section 8.22.020 defines "Public highway" as the entire width between the boundary lines of every way
publicly maintained by the Washington State Department of Transportation (WSDOT) or any county or city, when
any part thereof is generally for the use of the public for vehicular travel or a matter of right.
263
Table 4.10-6 Impact Magnitude and Description
Magnitude of Impact
Description
No Impact
The proposed Project would not cause an exceedance of
applicable noise limits and would not result in an increase in noise
levels at any noise -sensitive area.
Minor
The proposed Project would cause a temporary increase in noise
levels at noise -sensitive areas but would not exceed applicable
noise limits.
Moderate
The proposed Project would temporarily exceed applicable noise
limits and/or would cause a long-term increase in noise levels at
noise -sensitive areas.
Significant
The proposed Project would exceed applicable noise limits and/or
would cause a disruptive increase in existing noise levels; these
exceedances/increases would be long-term and unable to be
mitigated.
Noise impacts are primarily defined as exceedances of regulatory thresholds identified in section 1.10.2
at the locations where those limits apply. Noise from trucks on publicly accessible roadways constructed
as part of the Project would be exempt from regulatory limits. Noise from trucks on the facility site
would be subject to the limits, however, the Project will not result in an increase in truck volumes on the
site, and therefore will not result in an increase in overall noise levels from the site, though it may affect
the distribution of noise within the site. Since operational noise from the project would be either
exempt from regulatory limits or would not pose a change to existing noise levels, a quantitative noise
analysis was not performed. However, a qualitative discussion of potential noise effects is undertaken.
Similarly, noise from daytime construction activities is exempt and not subject to limitation under each
of the local and state environmental noise ordinances and requirements. Construction activities would
occur during daytime hours only, as defined by applicable ordinances, and would thus be exempt from
regulatory limits. However, annoyance due to increased noise levels during construction is still possible.
4.10.3.2 Impacts Analysis
4.10.3.2.1 Construction Impacts
Construction activities would occur during exempted hours only, and would thus not be subject to
regulation by state and local noise ordinances. Each of the applicable ordinances has a slightly different
definition of what constitutes exempted hours. The most restrictive hours are found in the King County
code, which would satisfy the requirements of all applicable ordinances if followed. Exempted hours are
as follows:
• Equipment excluding impact sources and heavy equipment: 7:00 AM — 10:00 PM weekdays, 9:00
AM — 8:00 PM weekends.
• Equipment excluding impact sources: 7:00 AM — 7:00 PM weekdays, 9:00 AM — 7:00 PM
weekends.
• All construction equipment: 8:00 AM — 5:00 PM weekdays, 9:00 AM — 5:00 PM weekends.
264
Even though it would not be subject to regulation, construction noise could still result in temporary
increases in noise near noise -sensitive areas such as residences and parks, which could interfere with
activities like speech and recreation, resulting in annoyance.
No construction would take place as part of the No Action Alternative; therefore, no noise impacts due
to construction would occur.
Under Alternative 2, the noise -sensitive areas most likely to be affected by construction noise are homes
along South 113th Street and the Duwamish Hill Preserve.
Under Alternative 3B, the noise -sensitive areas most likely to be affected by construction noise are
Codiga Park and homes along 50th Place South and 51" Place South.
Under Alternative 4, the noise -sensitive areas most likely to be affected by construction noise are homes
along 50th Place South, the south end of 51" Place South, the south end of 56th Place South, the Foster
Commons Apartments, and Codiga Park. The driveway construction on 51sY Place South could affect
nearby homes on 51" Place South and South 124th Street, but that construction activity would be of
especially short duration. Construction for the northern area of Alternative 4 may affect the
southernmost home on 47th Avenue South.
All impacts related to construction noise are expected to be minor since they would be temporary and
not subject to limitation from noise ordinances, provided they occur during allowable times.
4.1.0.3.2..2. Operations Impacts
Truck traffic along publicly accessible sections of roadway, including those constructed as part of this
project, would be exempt from noise limits. However, noise from trucks associated with the project may
still cause annoyance if increases in noise are experienced in noise -sensitive areas.
In each of the proposed alternatives, truck traffic would be rerouted. Once the project is completed,
trucks will no longer have to use neighborhood streets to access the BNSF intermodal facility, reducing
the existing noise along that route. In general, truck traffic along the new routes would comprise a small
proportion of overall traffic on pre-existing roadways that are part of the routes, and thus would only
provide a minimal increase in noise. The largest changes in noise associated with the Project would be
along roadways that are newly constructed as part of the Project, as well as any existing roadways
where trucks accessing the BNSF facility comprise a substantial portion of traffic.
The highest noise levels would occur immediately adjacent to the truck routes, so the highest noise
levels at noise -sensitive receptors would be expected in areas where the proposed route passes
especially close.
In the No -Action Alternative, trucks would continue to travel along South 124th Street, causing
significant noise levels for residents on that street as well as for the Tukwila Community Center.
In Alternative 2, truck routes do not pass adjacent to any noise -sensitive areas. Activity on the north end
of the BNSF facility could increase, potentially affecting the homes along 113th Avenue South and
Duwamish Hill Preserve. Based on the distance to those areas, the increase in noise is expected to be
minor. Alternative 2 would also require the closure of the SPAA shooting range, eliminating it as a
source of noise in the area. However, since the character of truck noise and shooting range noise is
substantially different, the presence of added truck noise may still be perceived as an increase in noise
265
even if overall noise levels decrease. Additionally, the increase in noise could be more pronounced
during hours when the shooting range was not in operation.
In Alternative 3B, the new access to the BNSF facility would be near residences on 51st Place South,
increasing noise levels not only on the new roadway, but also on the southern end of the facility, where
all truck traffic would now have to pass through. This increase could correspond to a moderate impact.
In Alternative 4, the proposed access to the BNSF facility is immediately adjacent to residences along
51st Place South. This increase in noise would likely be significant if not mitigated. The new route on the
north end of Alternative 4 would not be particularly close to residences and would not be expected to
cause any noise impacts.
4.10.4 Mitigation Measures
No significant adverse impacts are expected during construction or operation of the project. However,
some mitigation measures are proposed where noise could cause particular annoyance.
For Alternative 2, minimizing operations in the parts of the new area of the BNSF facility that are nearest
to the homes along 113th Avenue South and Duwamish Hill Preserve is recommended to keep the
increase in noise levels minimal in those areas, particularly during nighttime hours.
For Alterative 3B, a noise wall may be constructed along the south side of the new access road,
extending into the BNSF facility, to shield homes on 51st Place South from increased noise due to new
truck traffic. The noise wall should have a top height of at least 12 feet above pavement level, so that
elevated truck exhausts are blocked by the wall.
A noise wall is proposed as part of Alternative 4 to reduce noise from the access road to the BNSF facility
that would pass close to residences on 51st Place South. The noise wall is proposed along the west side
of the access road, extending north along the edge of the facility where trucks would be coming in. The
noise wall should have a top height of at least 12 feet above pavement level, so that elevated truck
exhausts are blocked by the wall.
To reduce the potential for construction noise to cause annoyance, best practices for construction noise
management should be followed. These may include the following (FTA 2019):
• Construct noise barriers, such as temporary walls or piles of excavated material, between noisy
activities and noise -sensitive receivers.
• Re-route truck traffic away from residential streets. Select streets with the fewest homes if no
alternatives are available.
• Site equipment on the construction lot as far away from noise -sensitive sites as possible.
• Construct walled enclosures around especially noisy activities or clusters of noisy equipment.
• Combine noisy operations to occur in the same time period. The total noise level produced will
not be substantially greater than the level produced if the operations were performed
separately.
• Avoid impact pile -driving where possible in noise -sensitive areas.
o Drilled piles or the use of a sonic/vibratory pile driver or push pile driver are quieter
alternatives where the geological conditions permit their use.
• Use specially quieted equipment, such as quieted and enclosed air compressors and properly
working mufflers on all engines.
266
4.10.5 Significant Unavoidable Adverse Impacts
A significant unavoidable adverse impact for noise would be an area where new heavy truck traffic
occurs at a location immediately adjacent to a noise -sensitive area, where factors prevent the
construction of a noise wall or other mitigation. No such areas have been identified, therefore no
significant unavoidable adverse impacts for noise are expected as part of this project.
267
4.11 IEnvironimentell Justice
This section provides an environmental justice (EJ) analysis of project impacts to surrounding
communities and addresses any disproportionate environmental and health impacts on minority and
low-income communities in the City of Tukwila (City) (WSDOT 2024a).
Environmental justice is defined under the HEAL Act (Chapter 70A.02 RCW) as "The fair treatment and
meaningful involvement of all people regardless of race, color, national origin, or income with respect to
the development, implementation, and enforcement of environmental laws, rules, and policies".
Minority is defined by Washington State Department of Transportation (WSDOT 2024a) as an individual
who is a member of the following group(s):
• Black (a person having origins in any of the black racial groups of Africa).
• Hispanic (a person of Mexican, Puerto Rican, Cuban, Central or South American, or the Spanish
culture or origin, regardless of race).
• Asian/Pacific Islander (a person having origins in the Far East, Southeast Asia or the Indian
subcontinent).
• Pacific Islander (a person having origins in any of the Pacific Islands).
• American Indian or Alaskan Native (any of the original peoples of North America, and who
maintains cultural identification through tribal affiliation or community recognition).
Tribal communities and populations are included under the definition of "minority". A summary of Tribal
communities and populations is provided in this chapter; however, detailed analysis and impacts would
be provided in Section 4.9 — Cultural Resources of this EIS.
Low-income is defined by the U.S. Census Bureau as having a household income that is at or below the
federally designated poverty level for a household of four; based on the annual statistical poverty
thresholds from the U.S. Census Bureau (USCB 2023b).
EJ analysis also seeks to provide equal access and participation in the public involvement process for
people who may have limited English proficiency (LEP). Limited English proficiency (LEP) is defined as
individuals who do not speak English as their primary language and who have a limited ability to read,
speak, write, or understand English (WSDOT 2024a). LEP populations will be evaluated through the
public participation plan for this project and not through this EJ section of the EIS.
268
• 4p
14.
. [I • ............ „„
Figure 4.11-1 Census Block Groups in the Study Area
269
CITY OF ILIKWIL.A
AiLLENTOWN EIS
ENVIRONMENTAL
JUSTICE
MEMORANDUM
Projject
Genera° PrOrd
Alternalit ye Study Areas
Alternative 2
Footprint
Alternative 313
"Iiti Footprint
, Alternative .1
FOCarinnt
Ns. Action Truck.
Percentage of Mtputity
Popullaifion
=I Mitt 20%
I=j 2irrnir, 40'Yo.
40% I[CJ 6CF%
80%
BO% 0:C., 1 OCrio
111111111111B
.0 in etre;
4.11.1 Affected Environment
To determine the presence of EJ populations in the affected environment, a 0.5-mile radius was applied
to the No Action Alternative', Alternative 2, Alternative 3B, and Alternative 4 to form study areas for
each of the alternative. The 0.5 mi radius was determined by recommended guidance from WSDOT
(2014).
Census tracts were used to analyze the presence of EJ populations in the alternatives' study areas. Tract
data was selected because it provides a stable set of geographic units for the presentation of statistical
data, and they contain a larger population size compared to other statistical boundaries used by the U.S.
Census Bureau (USCB 2022).
The U.S. Census Bureau was used to pull census tract level percentages of minority and low-income
populations. Percentages for City of Tukwila and King County were also listed for comparison. The
American Community Survey (ACS) five-year, 2018-2022 dataset was used for this analysis. Minority
data was pulled from the Race and Ethnicity ACS Demographic and Housing Estimates table (Table ID:
DP05), and low-income data was pulled from the Poverty Status in the Past 12 Months table (Table ID:
S1701). For the purposes of this analysis, an alternative or census tract is classified as having EJ
populations if their minority and low-income population percentages are equal to or higher than the
City of Tukwila and King County.
4.11.1.1 Minority Populations
This section identifies minority populations in the Alternative 2, Alternative 3B, and Alternative 4, and
No Action Alternative study areas.
4 11 1 1 1 Minority Populations within the No Action Alternative Study Area
Table 4.11-1 shows minority populations in the No Action Alternative study area compared to minority
populations in the City of Tukwila and King County. The No Action Alternative study area overlaps with
nine census tracts: Census Tract 119.01, Census Tract 261.01, Census Tract 261.02, Census Tract 262,
Census Tract 263, Census Tract 2828, Census Tract 273, Census Tract 271, Census Tract 272.
Table 4.11-1 Population by Race/Ethnicity (No Action Alternative)
Race/Ethnicity
No Action Alternative
Study Area*
City of Tukwila**
King County***
Population
Percentage
Population
Percentage
Population
Percentage
Non -Hispanic
White Alone
11,319
29%
6,195
29%
1,260,271
56%
'The existing truck route without detour is the "No Action Alternative". An existing temporary detour route is
being used due to structural damage to the 42nd Ave S bridge. The detour route was excluded from this EIS
analysis. Freeways were also excluded from the EIS analysis.
8 Census Tract 282 was included as it overlaps with the 0.5-mi buffer in the No Action Alternative study area. This
tract extends further from the immediate study area and truck routes, but the entirety of the tract would need to
be included as census tracts are predetermined geographical boundaries by the U.S. Census Bureau.
270
Race/Ethnicity
No Action Alternative
Study Area*
City of Tukwila**
King County***
Population
Percentage
Population
Percentage
Population
Percentage
Black or
African
American
alone
7,128
18%
3,675
17%
144,187
6%
American
Indian or
Alaskan Native
alone
292
1%
182
<1%
10,019
<1%
Asian alone
10,326
26%
5,225
24%
435,379
19%
Native
Hawaiian or
Pacific Islander
alone
738
2%
711
3%
16,415
<1%
Two or More
Races'
1,813
5%
665
3%
147,298
7%
Some Other
Race'
403
1%
123
<1%
11,929
<1%
Hispanic or
Latino (of any
race)
7,433
19%
4,793
22%
228,873
10%
Total
Minority2
28,133
71%
15,374
71%
994,100
44%
Total
Population
39,452
100%
21,569
100%
2,254,371
100%
SOURCE: *(USCB 2024a), **(USCB 2024b), ***(USCB 2024c)
1 "Two or More Races and "Some Other Race" does not include Hispanic or Latino populations (US Census Bureau 2024).
Hispanic or Latino (of any race) is in a separate row.
2 "Total Minority" in includes Black or African American, American Indian or Alaskan Native, Asian, Native Hawaiian or Pacific
Islander, Two or More Races, Some Other Race and Hispanic or Latino of any race as defined by WSDOT Environmental Manual
(2024a).
The total minority population in the No Action Alternative study area (71 percent) is the same as the
minority population in the City of Tukwila (71 percent) and greater than the minority percentages in
King County (44 percent). See Figure 4.11-2 for a visual representation of minority population in the No
Action Alternative study area by individual census tracts.
271
1
410
Sq o co m
ina r..J0
Arpolt.
„1"
...AL.., „..
Aittaitli
11
Figure 4.11-2 Minority Population by Census Tracts in the No Action Alternative Study Area
272
11,0ITY Or TUKWILA
ALLENTOWN El
ENVIRONMENTAL
JUSTICE
M EMORAIN 0:UM
No: Acliffn
fluff
0 5 NArle
Percentage: of MOroority
Poptdation
6,0% to NON,
Fol)R 6/6/2025
4 11 1 1 2. Minority Populations within the Alternative 2. Study Area
Table 4.11-2 displays minority populations in the Alternative 2 study area compared to minority
populations in the City of Tukwila and King County. Alternative 2 study area overlaps with four census
tracts: Census Tract 117, Census Tract 263, Census Tract 264, and Census Tract 272.
Table 4.11-2 Population by Race/Ethnicity (Alternative 2: Airport Way South)
Race/Ethnicity
Alternative 2 Study
Area*
City of Tukwila**
King County***
Population
Percentage
Population
Percentage
Population
Percentage
Non -Hispanic
White Alone
4,863
30%
6,195
29%
1,260,271
56%
Black or
African
American
alone
2,323
14%
3,675
17%
144,187
6%
American
Indian or
Alaskan Native
alone
175
1%
182
<1%
10,019
<1%
Asian alone
4,366
27%
5,225
24%
435,379
19%
Native
Hawaiian or
Pacific Islander
alone
213
1%
711
3%
16,415
<1%
Two or More
Races1
465
3%
665
3%
147,298
7%
Some Other
Race'
193
1%
123
<1%
11,929
<1%
Hispanic or
Latino (of any
race)
3,715
23%
4,793
22%
228,873
10%
Total
Minority2
11,450
70%
15,374
71%
994,100
44%
Total
Population
16,313
100%
21,569
100%
2,254,371
100%
SOURCE: *(USCB 2024a), **(USCB 2024b), ***(USCB 2024c)
1 "Two or More Races and "Some Other Race" does not include Hispanic or Latino populations (US Census Bureau 2024).
Hispanic or Latino (of any race) is in a separate row.
2 "Total Minority" in includes Black or African American, American Indian or Alaskan Native, Asian, Native Hawaiian or Pacific
Islander, Two or More Races, Some Other Race and Hispanic or Latino of any race as defined by WSDOT Environmental Manual
(2024a).
The minority population in the Alternative 2 study area (70 percent) is lower than the minority
population in the City of Tukwila (71 percent), but higher than the minority percentage in King County
(44 percent). See Figure 4.11-3 for a visual representation of minority population in the Alternative 2
study area by individual census tracts.
273
While
Cents:if
, ore, 4'110
,
',11ou,ft y
o
pn,
111111lIteta,
0,000000010000u10000000.0
r • .,0400tt00-0,00.00,1000000Nom00000 oo 0000
„ootpoilmo$4,t00 00000000001100001000 001 000000
" 00' 4it' 10101100001101oo
?,00 -00.100.0„„„„000001000010000
.•• 0000000,0„„„„„„„00,,,,,,,",„,,,,,00,000,10000.00,
00000000l000l
u11111111111111
Figure 4.11-.3 Minority Population by Census Tracts in the Alternative 2 Study Area
274
cnY OP Di 1.11KWIL.
AL.L.EN'R:1VVIA E111S
ENVIRONMENTA.L
JusTicE
MEMORANDUM
Alternative 2
Genyral Project Study
Areas
pesisi Alltematise 2
-11 Enderlin.
0.5 Proped
Puffer
Percenrage of Minority
Population
11,11111
1111111111111111111
4(111% 6Olttt
rArit, fret 8011%
FAIDtlt to "MUM,
NoUon
\°•0:00.'01.:00000,,,,;°00000000,000,00,000,000-00,0
°°°°°°',Eri.,,0 0,00,000!,00,00,0)0.00.0,000.000,0000,00
..0000'°0,0000,00•'00000000000000000000000/00000000000000000000•0
••••••••0t:000000000000
Dale: 6/6112021111
tt tkles
4 11 1 1 3 Minority Populations within the Alternative 3B Study Area
Table 4.11-3 displays minority populations in the Alternative 3B study area compared to minority
populations in the City of Tukwila and King County. Alternative 3B study area overlaps with six census
tracts: Census Tract 262, Census Tract 119.01, Census Tract 261.01, Census Tract 261.02, Census Tract
272, Census Tract 263.
Table 4.11-.3 Population by Race/Ethnicity (Alternative .3B: Improvements to 48th Place South)
Race/Ethnicity
Alternative 3B Study
Area*
City of Tukwila**
King County***
Population
Percentage
Population
Percentage
Population
Percentage
Non -Hispanic
White Alone
6,459
27%
6,195
29%
1,260,271
56%
Black or
African
American
alone
4,413
19%
3,675
17%
144,187
6%
American
Indian or
Alaskan Native
alone
292
1%
182
<1%
10,019
<1%
Asian alone
6,335
27%
5,225
24%
435,379
19%
Native
Hawaiian or
Pacific Islander
alone
298
1%
711
3%
16,415
<1%
Two or More
Races1
1,432
6%
665
3%
147,298
7%
Some Other
Race'
377
2%
123
<1%
11,929
<1%
Hispanic or
Latino (of any
race)
4,026
17%
4,793
22%
228,873
10%
Total
Minority2
17,173
73%
15,374
71%
994,100
44%
Total
Population
23,632
100%
21,569
100%
2,254,371
100%
SOURCE: *(USCB 2024a), **(USCB 2024b), ***(USCB 2024c)
1 "Two or More Races and "Some Other Race" does not include Hispanic or Latino populations (US Census Bureau 2024).
Hispanic or Latino (of any race) is in a separate row.
2 "Total Minority" in includes Black or African American, American Indian or Alaskan Native, Asian, Native Hawaiian or Pacific
Islander, Two or More Races, Some Other Race and Hispanic or Latino of any race as defined by WSDOT Environmental Manual
(2024a).
The minority population in the Alternative 3B study area (73 percent) is higher than the minority
population in the City of Tukwila (71 percent) and King County (44 percent). See Figure 4.11-4 for a
visual representation of minority population in the Alternative 3B study area by individual census tracts.
275
CITY OF TUKWILA
ALL ENTOVVN
ENVIRONMENTAL
JUSTICE
ME MORAINDUM
Allerhative38
General Project Study
Areas
Allen-10We 3B
- FooturinI
0 5 410 Study
Buffer
Percentage of Minority
Population
50% to 80%
Date': 5/6[20.25
0 4 Miles
Figure 4.114 Minority Population by Census Tracts in the Alternative .3B Study Area
276
4 11 1 1 4 Minority Populations within the Alternative 4 Study Area
Table 4.11-4 displays minority populations in the Alternative 4 study area compared to minority
populations in the City of Tukwila and King County. Alternative 4 study area overlaps with seven census
tracts: Census Tract 262, Census Tract 119.01, Census Tract 261.01, Census Tract 117, Census Tract
261.02, Census Tract 272, Census Tract 263.
Table 4.11-4 Population by Race/Ethnicity (Alternative 4: New 8ridgefrom SR 900)
Race/Ethnicity
Alternative 4 Study
Area*
City of Tukwila**
King County***
Population
Percentage
Population
Percentage
Population
Percentage
Non -Hispanic
White Alone
7,539
26%
6,195
29%
1,260,271
56%
Black or
African
American
alone
5,451
19%
3,675
17%
144,187
6%
American
Indian or
Alaskan Native
alone
333
1 %
182
<1%
10,019
<1%
Asian alone
9,136
31%
5,225
24%
435,379
19%
Native
Hawaiian or
Pacific Islander
alone
298
1%
711
3%
16,415
<1%
Two or More
Races1
1,575
5%
665
3%
147,298
7%
Some Other
Race'
414
1%
123
<1%
11,929
<1%
Hispanic or
Latino (of any
race)
4,605
16%
4,793
22%
228,873
10%
Total
Minority2
21,812
74%
15,374
71%
994,100
44%
Total
Population
29,351
100%
21,569
100%
2,254,371
100%
SOURCE: *(USCB 2024a), **(USCB 2024b), ***(USCB 2024c)
1 "Two or More Races and "Some Other Race" does not include Hispanic or Latino populations (US Census Bureau 2024).
Hispanic or Latino (of any race) is in a separate row.
2 "Total Minority" in includes Black or African American, American Indian or Alaskan Native, Asian, Native Hawaiian or Pacific
Islander, Two or More Races, Some Other Race and Hispanic or Latino of any race as defined by WSDOT Environmental Manual
(2024a).
The minority population in the study area (74 percent) is higher than the minority population in the City
of Tukwila (71 percent) and King County (44 percent). See Figure 4.11-5 for a visual representation of
minority population in the Alternative 3B study area by individual census tracts.
277
Ot
C1.1,t(lay
tt tt1 hal
tarata'
\ 111111!111
Sop so
04
not .r1,11
11111111111111111111111111111111111111
laaaajaala man; ;mamma.
81
IBIA,tn Mawr
i itiO
T°On1301/ t
k stoioMitS t
't14*
1' I
1
)\\
Figure 4.11-5 Minority Population by Census Tracts in the Alternative 4 Study Area
278
C ITY "1" U KW I L.A.
ALLENTOWN E. 1St
E N VIRON M ENrA L.
JU ST IC E
MEMORANDUM
A Hem attve 4:
Geller& Project Sturdy
Areas
Ailerriativt, 4
0,5 WIle Project
Ettuft'tn
Percentage MirmHty
1111111111111111
IllM4/4 SC.444
SIIIPtaa to "Ierittt,
d
,4trJRLfL
„ 1
ratalte: 6/6/2025
4 11 1 1 5 Summary of Minority Populations of the Study Areas
Between all alternatives, Alternative 4 study area has the highest minority percentage at 74 percent,
followed by Alternative 3B at 73 percent, the No Action Alternative at 71 percent, and Alternative 2 at
70 percent.
Both Alternative 3B and Alternative 4 have a higher percentage of minority population than the City of
Tukwila, whereas Alternative 2 has a minority population at 70 percent, which is 1 percent lower than
the City of Tukwila. The No Action Alternative has the same percentage of minority population as the
City of Tukwila. All alternatives have a higher percentage of minority population than King County (44
percent).
4.11.1.2 Low Income Populations
This section identifies low-income populations in the study area based on the census tract data across
Alternative 2, Alternative 3B, Alternative 4, and the No Action Alternative. "Population below poverty
level" by the U.S. Census Bureau will be used interchangeably with "low-income populations".
Population for whom poverty status is determined was compiled from the U.S. Census 2022: ACS five -
Year Estimates Data Profiles (ACS Poverty Status in the Past 12 Months, Table ID: S1701) for the
respective study areas. The same information was compiled for King County and the City of Tukwila for
comparison.
4.11.1.2..1 Low-income Populations within the No Action Alternative Study Area
Table 4.11-5 displays the presence of low-income populations (in percentages) in the No Action
Alternative study area compared to low-income populations in the City of Tukwila and King County as a
whole. The No Action Alternative study area overlaps with nine census tracts: Census Tract 119.01,
Census Tract 261.01, Census Tract 261.02, Census Tract 262, Census Tract 263, Census Tract 282, Census
Tract 273, Census Tract 271, Census Tract 272.
279
Table 4.11-5 Population Below Poverty Level (No Action Alternative)
Census Tract (King County,
Washington)
Population*
Number Below the
Poverty Level
Percent Below
Poverty Level
Census Tract 119.01
4,571
388
9%
Census Tract 261.01
3,747
520
14%
Census Tract 261.02
4,364
1,066
24%
Census Tract 262
6,013
472
8%
Census Tract 263
1,781
72
4%
Census Tract 271
3,950
942
24%
Census Tract 272
2,938
481
16%
Census Tract 273
6,542
1,121
17%
Census Tract 282
5,135
649
13%
Study Area Total
39,041
5,711
15%
City of Tukwila
21,200
2,821
13%
King County
2,223,603
187,794
8%
SOURCE: (USCB 2024d)
*The poverty universe estimates are not the same as the population estimates from the Census Bureau's Population Estimates
Program. They include group quarters populations only for noninstitutionalized group quarters; and excludes populations in
residents of college dormitories, military housing, all institutional group quarters, and children under age 15 not related to a
reference person within the household (U.S. Census Bureau 2021). Source: https://www.census.gov/programs-
surveys/saipe/guidance/model-input-data/denominators/poverty.html
The population below poverty level in the No Action Alternative study area (15 percent) is higher than
the population below poverty level in the City of Tukwila (13 percent) and King County (8 percent). See
Figure 4.11-6 for a visual representation of low-income population in the No Action Alternative study
area by individual census tracts.
280
nOevand
park
MI 01 [In ant),
Hrll
itelmtxt ,
'4. V
,$‘\/
Oot
tOtt Qt
14! y
) 4 FEN
Itil0
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tt,
ax4a7t2
/ U3(35
tc,u),lc Lo,cou
oc coo
Bt
coPP:tt'
1
Bryn Mawr
Figure 4.11-6 Low -Income Population by Census Tracts in the No Action Alternative Study Area
281
nu 0 TY OF TUKN. OLA
ALLE.w-OVUN EIS
ENVIRONMENTAL,
JUSTICE
MEMORANDUM
Po Action
GenetaI Project Study
Au
Irby Acton Truck
IRoutes
ILE Vile, I:Bore:rt.
1Puller
PoptdatIon Below
Poverty Lever
TBD 20td,
20% to 4.0%
/
Alt 38
6/6/2025
4.1.1..1..2..2. Low-income Populations within the Alternative 2. Study Area
Table 4.11-6displays the presence of low-income population percentages in the Alternative 2 study area
compared to low-income populations in the City of Tukwila and King County. Alternative 2 study area
overlaps with four census tracts: Census Tract 117, Census Tract 263, Census Tract 264, and Census Tract
272.
Table 4.11-6 Population Below the Poverty Level (Alternative 2: Airport Way South)
Census Tract (King County,
Washington)
Population*
Number Below the
Poverty Level
Percent Below
Poverty Level
Census Tract 117
5,696
889
16%
Census Tract 263
1,781
72
4%
Census Tract 264
5,820
1,506
26%
Census Tract 272
2,938
481
16%
Study Area Total*
16,235
2,948
18%
City of Tukwila
21,200
2,821
13%
King County
2,223,603
187,794
8%
SOURCE: (USCB 2024d)
*The poverty universe estimates are not the same as the population estimates from the Census Bureau's Population Estimates
Program. They include group quarters populations only for noninstitutionalized group quarters; and excludes populations in
residents of college dormitories, military housing, all institutional group quarters, and children under age 15 not related to a
reference person within the household (U.S. Census Bureau 2021). Source: https://www.census.gov/programs-
surveys/saipe/guidance/model-input-data/denominators/poverty.html
The population below poverty level in the Alternative 2 study area (18 percent) is higher than the
population below poverty level in the City of Tukwila (13 percent) and King County (8 percent). See
Figure 4.11-7 for a visual representation of low-income population in the Alternative 2 study area by
census tracts.
282
rh.a
port
hiLe
Center
VitY0 INV L.
'.1..urnalf...1
Figure 4.11-7 Low -Income Population by Census Tracts in the Alternative 2 Study Area
283
CITY OF TUKWILA
ALLENTOWN EIS
ENVIRONMENTAL
JUSTICE
MEMORANDUM
AlternatIve .2
General Project SLudy
Areas
fr—...1 Alternative 2
Footprint
0.5 f2de Project
Buffer
Percentage Populaton
Below IPoverty Level
0% to 20%
.222,
aate: 0/612025
0 3 Miles
4.1.1..1..2..3 Low-income Populations within the Alternative 3B Study Area
Table 4.11-7 displays the presence of low-income populations in the Alternative 3B study area compared
to low-income populations in the City of Tukwila and King County. Alternative 3B study area overlaps
with six census tracts: Census Tract 119.01, Census Tract 261.01, Census Tract 261.02, Census Tract 262,
Census Tract 263, Census Tract 272.
Table 4.11-7 Population Below Poverty Level (Alternative .3B: Improvements to 48th Place South)
Census Tract (King County,
Washington)
Population*
Number Below the
Poverty Level
Percent Below
Poverty Level
Census Tract 119.01
4,571
388
9%
Census Tract 261.01
3,747
520
14%
Census Tract 261.02
4,364
1,066
24%
Census Tract 262
6,013
472
8%
Census Tract 263
1,781
72
4%
Census Tract 272
2,938
481
16%
Study Area Total*
23,414
2,999
13%
City of Tukwila
21,200
2,821
13%
King County
2,223,603
187,794
8%
SOURCE: (USCB 2024d)
*The poverty universe estimates are not the same as the population estimates from the Census Bureau's Population Estimates
Program. They include group quarters populations only for noninstitutionalized group quarters; and excludes populations in
residents of college dormitories, military housing, all institutional group quarters, and children under age 15 not related to a
reference person within the household (U.S. Census Bureau 2021). Source: https://www.census.gov/programs-
surveys/saipe/guidance/model-input-data/denominators/poverty.html
The population below poverty level in the Alternative 3B study area (13 percent) is same as the
population below poverty level in the City of Tukwila (13 percent), but higher than King County (8
percent). See Figure 4.11-8 for a visual representation of low-income population in the Alternative 3B
study area by census tracts.
284
1'11 11,11 0).1'0
T ,ct63
CITY OF TuKW[1....A
AtilltENTEAVNI EIS
ENVIRONMENTAL
JUSTICE
MEMORANDUM
Alternattve 3113
Gems Project Study
Areas
Ann, Alternative 3B
Fordo' int
0.5 NSItit Enalest
Buffer
Population Bellow
Poverty Irtevel
Lad Oritt to 20%
• Enra, St CO%
Ii.5,W2025
0.1
Figure 4.11-8 Low -Income Population by Census Tracts in the Alternative .38 Study Area
285
4.1.1..1..2..4 Low-income Populations within the Alternative 4 Study Area
Table 4.11-8 displays the presence of low-income populations (in percentages) in the Alternative 4 study
area compared to minority populations in the City of Tukwila and King County as a whole. Alternative 4
study area overlaps with seven census tracts: Census Tract 117, Census Tract 119.01, Census Tract
261.01, Census Tract 261.02, Census Tract 262, Census Tract 263, Census Tract 272.
Table 4.11-8 Population Below Poverty Level (Alternative 4: New Bridge from SR 900)
Census Tract (King County,
Washington)
Population*
Number Below the
Poverty Level
Percent Below
Poverty Level
Census Tract 117
5,696
889
16%
Census Tract 119.01
4,571
388
9%
Census Tract 261.01
3,747
520
14%
Census Tract 261.02
4,364
1,066
24%
Census Tract 262
6,013
472
8%
Census Tract 263
1,781
72
4%
Census Tract 272
2,938
481
16%
Study Area Total*
29,110
3,888
13%
City of Tukwila
21,200
2,821
13%
King County
2,223,603
187,794
8%
SOURCE: (USCB 2024d)
*The poverty universe estimates are not the same as the population estimates from the Census Bureau's Population Estimates
Program. They include group quarters populations only for noninstitutionalized group quarters; and excludes populations in
residents of college dormitories, military housing, all institutional group quarters, and children under age 15 not related to a
reference person within the household (U.S. Census Bureau 2021). Source: https://www.census.gov/programs-
surveys/saipe/guidance/model-input-data/denominators/poverty.html
The population below poverty level in the Alternative 4 study area (13 percent) is same as the
population below poverty level in the City of Tukwila (13 percent) and higher than King County (8
percent). See Figure 4.11-9 for a visual representation of low-income population in the Alternative 4
study area by census tracts.
286
K unLv
KalKOnal
inv
items%
41(26 i
SeaTa c
Dryn Mawr
ok
f/Va5bing
Figure 4.11-9 Low -Income Population by Census Tracts in the Alternative 4 Study Area
287
C1T"Y OF "INKVVVLA
AL LENTOVVN
ENVIRONMENTAL.
JUISTIICE
MEMORA.NDUM
Ant, V4t 4
Gonerr, 0 Project Study
Areas
ABievviativk::!
Foutp
IVHIrJ FKrojKKI
Buffet
Pop o Darien Below
POVerty LeVei
ItiOrk
2t:St Jr) 40'SJ
F)1 DidU,;
I) 4 IK4i:IIKK
4.1.1..1..2..5 Summary of Low -Income Populations of the Study Areas
Between all alternatives, Alternative 2 has the highest percentage of populations below poverty level at
18 percent, followed by the No Action Alternative at 15 percent, and Alternative 3B and Alternative 4
both at 13 percent.
Both Alternative 2 and the No Action Alternative have a higher percentage of populations below poverty
level than the City of Tukwila, and Alternative 3B and Alternative 4 have a minority population at 13
percent, which is the same as City of Tukwila. All alternatives have a higher percentage of populations
below poverty level than King County (8 percent).
4.11.1.3 Tribal Communities and Populations
The Washington Territory was organized on behalf of the United States in 1853 and the Treaty of Point
Elliott, ratified in 1859, was signed by the Duwamish, Suquamish, Snoqualmie, Snohomish, Lummi,
Skagit, Swinomish and other tribes on January 22, 1855. One of the Snoqualmie Indian chiefs signed in
the name of the Stillaguamish, Snohomish, and Snoqualmie Indians (12 Stat. 971). The Treaty of Point
Elliot resulted in the Indian Tribes ceding thousands of acres of lands to the federal government in
exchange for reservations and guaranteed perpetual access to ancestral fishing, hunting, and gathering
sites, referred to as usual and accustomed areas (U&A).
During the 1960s and 1970s, State laws attempted to limit Indian fishing to only reservation lands. In
response, Indian fishers organized a movement grounded in "fish -ins" and public education to challenge
these continued threats to their treaty fishing rights. The fishers were faced with harassment, violence,
and arrest, events that are referred to as the Fish Wars. These Fish Wars were pivotal in enforcing rights
for treaty -reserved fish and shellfish resources within U&A areas.
The Tribes' reserved rights were reaffirmed in 1974 (and upheld in 1979) during a United States vs.
Washington court case that became known as the Boldt Decision, named for trial court judge, George
Hugo Boldt. This case reaffirmed the right of the Indian tribes in Washington State to co -manage salmon
and other fish within the state and to also continue harvesting fish in accordance with the various
treaties. Today, the Indian Tribes in Washington State co -manage salmon and other fish with the state
and to also continue harvesting fish in accordance with the various treaties (384 F. Supp. 312, W. Dist.
WA, [1974]).
The Muckleshoot Indian Tribe and Suquamish Tribe hold adjudicated fishing rights in the Duwamish
Waterway and Elliot Bay, among other areas. For purposes of the Treaty, the term "fish" includes both
anadromous fish and naturally occurring shellfish beds. Fish and shellfish have always played a very
important role in Indian tribal economy and culture since time immemorial, including both subsistence
and ceremonial practice. Tribes have historically harvested, currently harvest, and intend to harvest fish
and shellfish in the future within their U&A fishing grounds.
Additionally, the Duwamish Tribal Organization headquarters is directly across from the Study Area
(Duwamish Tribal Services Organization 2018). The Duwamish Tribal Organization is not federally
recognized; however, many Duwamish people have chosen to move to the Port Madison Indian
Reservation or enroll in the Muckleshoot Indian Reservation, while other Duwamish people continue to
seek independent Duwamish tribal status (Suquamish 2023).
288
There are no Tribal lands within the Study Area.
4.11.2 Relevant Plans, Policies, and Regulations
There are currently no legally binding requirements for environmental justice analysis for SEPA (WSDOT
2023). Additionally, SEPA EIS requirements in Chapter 197-11 WAC does not list environmental justice as
a required element of the environment. Environmental justice is analyzed in this SEPA DEIS due to the
presence of high minority and low-income populations in the City, as well as comments received during
the scoping process.
Applicable plans and guiding documents that assist with making an informed EJ analysis for this project
are listed in Table 4.11-9
Table 4.1.1-9 Relevant Plans, Policies, and Regulations
Laws and Regulations
Description
Federal
Due to the revocation of Executive Orders 12898 and 14098, there are currently no federal
regulations and documents applicable to the Project.
State
Washington State Department of
Transportation (WSDOT), Environmental
Manual
The WSDOT Environmental Manual M 31-11 is a
compilation of environmental policies and processes
that is to be used as a guidance resource for the
Washington State Department of Transportation
(WSDOT) and its environmental consultants. The
manual includes a chapter on Environmental Justice
(Chapter 460), which provides direction necessary for
project teams to meet federal and state
environmental justice (EJ) requirements during the
environmental review process for transportation
improvement projects.
Local
There are no local regulations applicable to the Project
4.11.3 Methodology
In order to determine the ways in which the No Action Alternative, Alternative 2, Alternative 3B, and
Alternative 4 could disproportionately impact environmental justice populations, this analysis reviewed
the effects analyses presented in Sections 4.1 through 4.11 (the Environmental Analysis resource
sections) of this EIS to identify the overall effects from the proposed Project. When adverse impacts
were identified in the discipline reports for the other elements of the environment, these impact
determinations were assessed for the potential for environmental impacts to disproportionately affect
environmental justice populations of interest. Where mitigation measures that could avoid, minimize, or
reduce the identified impact below the level of significance were identified, these were also considered.
289
In order to determine the ways in which the Proposed Action and Alternative 1 could potentially impact
environmental justice populations, the City first reviewed the effects analyses presented in Sections 4.1
through 4.11 of this EIS to identify the overall effects from the Project. After identifying adverse effects,
project effects that could affect people differently were isolated. For example, the City examined the
effects of construction air quality on environmental justice populations, because environmental justice
populations living or working closer to project construction could be affected more than people living
farther away. In other words, the City evaluated whether low-income or minority populations would
experience disproportionately high and adverse effects as a result of the proposed Project.
The term "disproportionately high and adverse effects" is used to encompass both human health and
environmental effects. This analysis considers both short-term (construction) and long-term (operation)
effects specific to populations that could experience disproportionate effects as a result of the proposed
Project.
A significant impact would occur if the Project would cause an irreversible disproportionate adverse
effect on environmental justice populations.
A majority of the construction impacts would occur within the immediate project area. Operational
impacts would include new alternative routes to the BNSF Intermodal Facility in Allentown. Impacts with
the potential to affect environmental justice communities could occur with respect to air quality, noise,
transportation, water resources, public services and utilities, cultural resources, visual resources and
aesthetics, and health and safety and are discussed further below.
Any adverse construction impacts related to geology and soils, water resources, plants and animals
would be anticipated to be localized to the project site or not have the potential to impact people
directly, so no environmental justice community impacts are anticipated. Hence, the impacts in Section
4.11.4 would not discuss any of these environmental impacts.
The subsections below provide an analysis of whether the construction and operational impacts
identified in the respective chapters would disproportionality affect environmental justice populations.
To determine the magnitude of impacts, the following categories are defined in Table 4.11-10:
Table 4.11-10 Ma0nitude of impacts
Magnitude of
Disproportionate
Impact
Description
No Impact
The proposed Project would not have disproportionate impacts to
environmental justice populations in the study area or census tract.
Minor
The proposed Project would have temporary and minor disproportionate
impacts to environmental justice populations in the study area or census
tract, and mitigation measures would help restore environment to pre-
existing conditions.
Moderate
The proposed Project would have temporary and long-term
disproportionate impacts to environmental justice populations in the
study area or census tract, but mitigation actions can be applied to
reduce the impact to a minor level.
290
Magnitude of
Disproportionate
Impact
Description
Significant
The proposed Project would cause long-term or irreversible
disproportionate impacts to environmental justice populations study
area or census tract. No mitigation measures could be applied.
4.11.4 Impacts Analysis
4.11.4.1 Construction Impacts
4 11 4 1 1 No Action Alternative
Under the No Action Alternative, impacts from construction are not applicable because the No Action
Alternative is the existing truck route to the BNSF Intermodal facility; truck traffic would continue under
current operating conditions.
4 11 4.1..2. Alternative 2., Alternative 3B, and Alternative 4
4.11.4.1.2.1 Land Use, Shoreline Use, and Recreation
For land use, construction for Alternative 2 would be consistent with zoning regulations and future land
use designations. Alternative 3B may have minor and temporary construction impacts to a low -density
residential area along Railroad Avenue. Alternative 4 construction may require parcel rezoning or
acquisitions, and residents in affected parcel 0179002255 could be displaced. No disproportionate
construction land use or displacement impacts are anticipated to environmental justice populations in
Alternative 3B and 4, as impacts would be commonly felt among all populations within the community.
For shoreline use, Alternative 2 does not overlap with shoreline use areas or buffers. Construction
activities for Alternative 3B and 4 would occur within the shoreline designations Urban Conservancy and
Residential Shoreline along with their buffer areas. Alternative 3B would introduce a new bridge, and
Alternative 4 would have construction activities within existing roadways in these shoreline designated
areas. No disproportionate shoreline use impacts are anticipated to environmental justice populations in
Alternative 3B and 4, as impacts would be commonly felt among all populations.
For recreation, construction activities for Alternative 2 would displace the Seattle Police Athletic
Association (SPAA), a popular and historic recreational facility. Construction activities for Alternative 3B
would temporarily impact public access to the Duwamish River, Green River Trail, and Codiga Park; and
Alternative 4 would temporarily impact public access to the east entrance of Codiga Park. No
disproportionate recreation impacts are anticipated to environmental justice populations across all
alternatives during construction, as recreational impacts would be commonly felt among all populations
in the area.
Proposed mitigation measures are described in Section 4.4.5.
4.11.4.1.2.2 Air Quality and Greenhouse Gases
As discussed in Section 4.5, impacts to air quality and greenhouse gases will consist of emissions from
fuel combustion in engines of construction equipment, fugitive dust from land disturbance activities as
well as vehicle traffic on unpaved roads, minor VOCs would be generated from paving activities, and
minor commuting emissions from workers traveling to the site. Standard BMPs would be implemented
291
to reduce impacts, including dust suppression measures, speed limits, wheel washing, load covering, and
engine emission compliance.
Construction impacts to air quality and greenhouse gases would primarily be localized to each
alternative, proportionate to the impact size. For example, greater surface disturbance alternatives have
greater impacts and alternatives that have longer construction duration and/or more equipment
requirements have greater impacts. Alternatives with more pavement area will have increased VOC
impacts. Worker commuting is assumed to be similar among the construction alternatives. None of
these impacts are anticipated to disproportionately affect EJ populations.
4.11.4.1.2.3 Transportation
Similar routes are anticipated to be used during construction and operations; hence, impacts are
anticipated to be similar. During construction, construction vehicles would be used to access the
proposed Project site. Alternative 2 and 3B routes have similar impacts, where minor impacts are
anticipated towards level of service (LOS) and vehicle miles traveled (VMT) on existing roads due to
construction.
4.11.4.1.2.4 Health and Safety
As mentioned in Section 4.7, if the inadvertent release and exposure of hazardous materials were to
occur, the impacts would be felt by all populations, including environmental justice populations;
therefore, the project would not cause any disproportionate health and safety impacts on specific
populations during construction. Proposed mitigation measures would be carried out by the selected
contractor in accordance with RCW 49.17 and WAC 173-303 as outlined in Section 4.7.5.
4.11.4.1.2.5 Public Services and Utilities
For all three build alternatives, there may be a need for police and sheriff, fire and emergency, sewer,
electricity, solid waste and water services at the construction site. If accidents were to occur, there may
be an increased need for emergency services; however, the increased need would not cause a
decreased level of service in the City. Hence, no disproportionate impacts to environmental justice
populations are anticipated. Stormwater runoff from ground disturbing activities could occur during
construction, and the Applicant would be required to comply with state and local stormwater pollution
prevention measures as per Section 4.8.4.2.4.
4.11.4.1.2.6 Cultural Resources
Project development could have disproportionate impacts on Tribes and Tribal communities.
Construction activities for Alternative 2, Alternative 3B, and Alternative 4 will directly alter traffic during
construction, which could impact Tribal access to U&A areas and Tribal resources; however, these
impacts would be temporary and moderate. These temporary impacts may include lane closures, traffic
re-routing, and traffic delays. Additional temporary impacts may include increased noise, vibration, and
dust during construction activities. If a spill were to occur during construction, it could result in minor to
moderate impacts to Tribal resources and U&A areas. Impacts associated with plants and animals that
provide important subsistence and medicinal resources to Tribal communities could potentially result in
minor to moderate impacts on Tribal communities.
4.11.4.1.2.7 Noise
As described in Section 4.10, construction activities for Alternative 2, Alternative 3B, and Alternative 4
could temporarily increase noise levels, which would interfere with activities like speech and recreation
292
in noise -sensitive areas, resulting in annoyance. Temporary construction noise from the project would
be felt by all populations, including environmental justice populations; therefore, the Project would not
cause any disproportionate noise impacts on specific populations during construction. Mitigation
measures are proposed in Section 4.10.4.
4.11.4.1.2.8 Visual Resources and Aesthetics
As described in Section 4.12, construction of the three build alternatives would result in negative
impacts to visual resources and aesthetics to all populations who view them, including environmental
justice populations. Of the three build alternatives, Alternative 2 will have the least impact on
environmental justice populations because it is zoned as a heavy manufacturing and industrial center,
and would not infringe on residentially zoned areas. Alternative 3B and Alternative 4 have mixed zoning
requirements, but construction would impact residential areas for both alternatives. The construction
impacts for Alternative 3B are less than that of Alternative 4.
4.11.4.2 Operations Impacts
Once operational, impacts with the potential to affect environmental justice communities could include
land use, shoreline use, and recreation; noise; transportation; health and safety; and public services and
utilities. Any adverse operational impacts related to geology and soils, water resources, plants and
animals, air quality, and cultural resources would be anticipated to be localized to the project site or not
have the potential to impact people directly, so no environmental justice community impacts are
anticipated.
4 11 4.2.1. No Action Alternative
The No Action truck route extends through residential and commercial streets such as 42nd Avenue
South and South 124th Street. Heavy truck traffic could bring adverse land use, shoreline and recreation,
noise, and health and safety impacts as these streets are not meant for industrial level traffic, and
impacts could be felt by the local residents and community.
4 11 4.2..2. Alternative 2., Alternative 3B, and Alternative 4
4.11.4.2.2.1 Land Use, Shoreline Use, and Recreation
For land use, operations of Alternative 2 and Alternative 3B truck routes would not impact residential or
community areas as routes are only adjacent to manufacturing and light industrial zones. However,
Alternative 4 operational impacts would be identical to construction, where acquisitions and rezoning
may may displace residents. No disproportionate operational land use or displacement impacts are
anticipated to environmental justice populations in Alternative 4.
For shoreline use, Alternative 2 and 4 would be consistent current or planned use of shoreline
designations during operations. The presence of a new bridge in the shoreline use area for Alternative
3B may have long term impacts to shoreline use and ecological functions. No disproportionate
operational shoreline use impacts are anticipated to environmental justice populations in Alternative
3B, as if any ecological function impacts were to occur and affect the public, it would be commonly felt
among all populations.
For recreation, Alternative 2 and 4 would not directly alter or impact recreational areas during
operations. The new bridge in Alternative 3B, as mentioned in Section4.4, would be constructed with
sidewalks; and residents would be able to more easily access the Green River Trail from Codiga Park by
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crossing the Duwamish River via the new bridge. No disproportionate recreational impacts are
anticipated during operations to environmental justice populations.
Proposed mitigation measures are described in Section 4.4.5.
4.11.4.2.2.2 Air Quality and Greenhouse Gases
Operational impacts to air quality and greenhouse gases are primarily related to the change in vehicle
miles traveled at this stage of analysis. Table 4.6-8 details the calculations for each alternative, with
Alternative 2 being the lowest and Alternative 4 being the highest. No disproportionate air quality or
greenhouse gas emissions impacts to EJ populations are anticipated from operation of the alternatives.
4.11.4.2.2.3 Transportation
Operations of the proposed alternatives will have no disproportionate impacts on Environmental Justice
(EJ) populations. While minor impacts may occur in terms of level of service (LOS) and vehicle miles
traveled (VMT) on existing roads, these impacts are expected to be minimal and similar across all
alternatives, as well as across minority and low-income populations.
4.11.4.2.2.4 Health and Safety
For all truck routes, hazardous materials such as petroleum products may be transported to the BNSF
intermodal facility. If a spill were to occur, this could adversely impact soils, groundwater, surface
waters and is potentially hazardous to the public. The project would not cause any disproportionate
health and safety impacts on specific populations; and any adverse impacts would be felt by all
populations, including environmental justice populations.
4.11.4.2.2.5 Public Services and Utilities
No additional utility connections or emergency response services are anticipated for operations of the
project. However, all the alternatives would result in increase of impervious surface and therefore the
amount of surface water runoff is anticipated to increase with truck operations on the routes. Onsite
stormwater would be collected and treated as per city, state and federal guidelines. Additional electrical
utilities would be required for new street lighting associated with road improvements but would not
affect infrastructure or electricity on adjacent properties. Overall, the project would not cause any
disproportionate public services and utilities impacts on environmental justice populations.
4.11.4.2.2.6 Cultural Resources
Project operation could have disproportionate impacts on Tribes and Tribal communities. Operation of
the facility would result in minor impacts to Tribal resources or U&A areas. Visual changes would result
in viewshed impacts; however, the setting is urban and industrial so the impact would be considered
minor. Operational noise may result in minor impacts to Tribal resources and U&A areas. Hazardous
materials such as petroleum products may be transported to the BNSF intermodal facility on all truck
routes. If a spill were to occur during operation, it could result in minor to moderate impacts to Tribal
resources and U&A areas. Impacts associated with plants and animals that provide important
subsistence and medicinal resources to Tribal communities could potentially result in minor to moderate
impacts on Tribes and communities.
4.11.4.2.2.7 Noise
If a build Alternative is selected, trucks will no longer have to use neighborhood streets to access the
multimodal facility, reducing the existing noise along routes near noise -sensitive areas. During
294
operations, the highest noise levels for Alternative 2, Alternative 3B and Alternative 4 would be
expected in areas immediately adjacent to the proposed alternatives' truck routes as described in
Section 4.10. Operational noise impacts would be felt by all populations, including environmental justice
populations; therefore, the Project would not cause any disproportionate noise impacts on specific
populations during operations for all alternatives.
4.11.4.2.2.8 Visual Resources and Aesthetics
As described in Section 4.12, operation of the three build alternatives would result in negative impacts
to visual resources and aesthetics to all populations who view them, including environmental justice
populations. Of the three build alternatives, Alternative 2 will have the least impact on environmental
justice populations because it is zoned as a heavy manufacturing and industrial center, and would not
infringe on residentially zoned areas. Alternative 3B and Alternative 4 have mixed zoning requirements,
but operations would impact residential areas for both alternatives. Operation impacts for Alternative
3B would be substantially less than Alternative 4 if mitigation measures are applied. Alternative 4 would
have the greatest impact on visual resources of the three build alternatives; however, adverse impacts
would not be disproportionately high for environmental justice populations.
4.11.5 Mitigation Measures
There would be no disproportionately high and adverse impacts on environmental justice populations
during construction and operations. Mitigation and standard BMPs would be implemented and would
reduce the likelihood and magnitude of identified adverse impacts. These impacts, however, would not
be absorbed disproportionately by minority or low-income populations, but rather by all populations
within the study area.
4.11.6 Environmental Justice Determination
There are no significant unavoidable adverse impacts associated with environmental justice populations.
295
4.12 VisulaD Resources and Aesthetics
4.12.1 Affected Environment
For this section of the EIS, the affected environment, or area of visual effect (AVE), for Visual Resources
and Aesthetics is generally defined as the limit of disturbance of proposed construction and the truck
route for each alternative plus a half -mile buffer. The AVE was determined by physical constraints of the
environment, the level of existing urban and industrial or commercial development, and the
physiological limits of human sight. More information about the AVE determination is in Section 4.12.3:
Methodology.
The general landscape and visual environment is considered an urban setting. Depending on the
Alternative, the composition and ratio of residential areas to recreational, commercial, and industrial
areas varies. The AVE for each of the four proposed alternatives are shown in detailed figures under
each alternative; the AVEs overlap and share many features in common. The urban soils, vegetation, and
climate are consistent across the alternatives.
4.12.1.1 Visual Character of Land Use and Landform Common to All Alternatives
The landform of the alternatives is relatively low and flat along the Duwamish River valley, with hills
sloping upwards to higher ground to the northeast and southwest. I-5 and SR 599 function as visual
markers of this landscape unit that divide the low-lying areas from the uplands.
4.12.1.2 Visual Character of the Natural Environment Common to All Alternatives
The central ecological feature for alternatives is the Duwamish River which generally transects the AVEs
from the south east to the north. The Duwamish River banks, and Green River Trail, parks, open spaces,
and residential areas are widely treed and vegetated with a mix of native and cultivated species of both
deciduous and evergreen variety, offering multi -season visual variety that softens the texture and
geometry of commercial, industrial, and other adjacent highly developed areas. Except for entrance
areas, the full length of the western boundary of the BNSF facility is obscured from view by a variety of
dense vegetation including mature coniferous and deciduous trees, shrubs, vines, and herbaceous
plants.
The AVEs for the alternatives do not include any priority habitat for threatened or endangered species
(refer to Section 4.3). Wildlife is present within AVEs of the alternatives, but not in great abundance
considering the extensive development and level of human activity. Vegetation in residential areas,
parks, and open spaces offer some habitat and refugia to birds and small to medium-sized mammals
that are accustomed to human presence and activities. These animals may congregate on or near the
river and in areas with greater proportions of vegetative cover.
4.12.1..E Visual Character of the Community, Social, and Cultural Environments common to All
Alternatives
Buildings within the AVE of the alternatives vary in their age, architectural style, and function. Industrial
buildings typically have a plain facade and are one to two stories tall and have limited windows.
Commercial and office buildings in this area are designed to have more visual appeal to viewers and
comfort for the users of the building. Commercial and office buildings' architecture and design include
many large windows and landscaping around the buildings, parking lots, and other spaces that enhance
visual appeal. Commercial and office buildings are the tallest structures in the No Action Alternative
296
AVE; they range from one to six stories. Residential structures in this area are a mix of ages and styles.
Buildings within Low Density Residential zoning are typically single stand-alone structures one to two
stories tall, and building types within Medium and High -Density Residential areas can include building
types like townhomes, condominiums, and apartment buildings. These buildings can be one to four
stories tall. Vegetation in residential areas is inconsistent in density, height, and type, as the natural
environment tends to reflect the style, needs, and preferences of the property owners.
Other structures that shape the community visual character of the alternatives include bridges across
the Duwamish River. The South 102nd Street bridge is a two-lane concrete and steel bridge supported by
piers placed within the Duwamish River. At South 112th Street, the Green River Trail crosses the
Duwamish River via a pedestrian bridge. This bridge is constructed of steel and concrete and is
supported by in -water piers towards either bank of the river. The Tukwila International Boulevard bridge
is a five lane, concrete and steel bridge that spans the width of the Duwamish River without using in -
water piers. The Seattle light rail is elevated on concrete platform supported tracks as high as three
stories in places within the Alternative 2 AVE. The light rail crosses the Duwamish River alongside the
East Marginal Way South bridge. The East Marginal Way South bridge is a three -lane, concrete and steel
structure. Both the light rail bridge and the East Marginal Way South bridge span the Duwamish River
without in -water piers. At South 119th Street, a wooden pedestrian bridge crosses the Duwamish. This
bridge is supported by in -water piers, and is only for use by pedestrians and cyclists. The Allentown
Bridge is a two lane, steel girder bridge that crosses the river at 42nd Avenue South. I-5 crosses the
Duwamish river using two four -lane concrete and steel bridges, one bridge for northbound traffic and
one bridge for southbound.
Infrastructure within the alternatives includes the BNSF rail lines and intermodal facility, highways and
Interstate 5, the Sound Transit Link light rail, cellular towers, and overhead transmission and fiberoptic
lines (Sound Transit 2025). The west boundary of the BNSF intermodal facility is densely vegetated along
the security fence with a variety of mature trees, shrubs, and other plants, which acts as a visual buffer
of the industrial facility from the adjacent residential areas. Furthermore, the BNSF facility is subject to a
special height limitation which serves to reduce the visibility of the of the industrial area from residential
areas.
The Seattle light rail is elevated on concrete platform supported tracks as high as three stories in places
within the alternatives. The light rail, industrial rail, and highways are generally oriented southeast to
northwest, following the path of the Duwamish River and the topography of the river valley.
4.12.1.4 No Action Alternative
The affected environment of the No Action Alternative consists of the current BNSF truck route and a
half -mile buffer, Figure 4.12-1. The half -mile buffer was used for visual analysis because this distance
falls within the FHWA's `foreground' range. There would be no new construction for this alternative. A
detailed description of the No Action Alternative components and routes are provided in Section 3.3.
297
AVINVA»ve,
4.12..1.4.1 Visual Character of Land Use and Landform for the No Action Alternative
The study area for the No Action Alternative is comprised of industrial, residential, infrastructure, and
commercial areas interspersed with green spaces such as parks, and trails. The area is highly developed
with infrastructure such as highways and train tracks, with the central portion of the AVE located within
a Commercial/Light Industrial zone and major industrial areas are towards the north and the east of the
AVE. Much of the land use in AVE for the No Action Alternative consists of residential zoning located in
the cities of Tukwila and Seattle, and unincorporated King County. Detailed descriptions of the affected
areas of land use, recreational areas, and shoreline use are provided in Section 4.4.
The AVE for the No Action Alternative overlaps with the land use zoning areas listed in Table 4.12-1.
Table 4.12-1 Land Use Zoning within the AVE for the No Action Alternative
Municipality
Land Use Zoning
City of Tukwila
•
Heavy Industrial (HI)
•
Light Industrial (LI)
•
Manufacturing Industrial Center/ Heavy (MIC/H)
•
Manufacturing Industrial Center/ Light (MIC/L)
•
Commercial Light Industrial (CLI)
•
Residential Commercial Center (RCC)
•
Regional Commercial Mixed Use (RCM)
•
Mixed Use Office (MUO)
•
Regional Commercial (RC)
•
Office (0)
•
Neighborhood Commercial Center (NCC)
•
High Density Residential (HDR)
•
Medium Density Residential (MDR)
•
Low Density Residential (LDR)
City of Seattle
•
Neighborhood Residential (NR1)
•
Mixed Zone Residential/Commercial (NC1-40
(M))
King County
•
Industrial with Special District Overlay (1-SO)
•
Neighborhood Business with Property -specific
development standards (NB-P)
•
Urban Residential (R-6), (R-8), (R-24)
•
Urban Residential with Property -specific
development standards (R-12-P), (R-24-P), (R-48-
P)
•
Urban Residential with Property -specific
development standards and Special District
Overlay (R-48-P-SO)
Sources: (King County 2024a; King County 2025b; City 2024b; City of Seattle 2024a)
Because the No Action Alternative is located in a river valley bordered by slopes and hills, the
topography limits the viewshed to the 'foreground' distance.
4.12..1.4.2. Visual Character of the Natural Environment for the No Action Alternative
The AVE for the No Action Alternative overlaps with the green spaces and recreational areas listed in
Table 4.12-2.
299
Table 4.12-7 Recreational Areas within the AVfor the No Action Alternative
Municipality
Recreational Areas
City of Tukwila
•
Duwamish River
•
Green River Trail
•
Tukwila Community Center
•
Duwamish Park
•
Codiga Park
•
Riverton Park
•
Riverton Mini Park
•
Southgate Park
•
Tukwila Pool
•
Macadam Wetlands and Winter Garden
•
Joseph Foster Memorial Park/ Lee Philips Park
•
Foster Golf Links
•
57th Avenue South Mini Park
•
Pamela Drive Open Space
King County
•
Skyway Farms
•
West Skyway Natural Area
Sources: (City 2024d; King County 2022b)
The soils in the footprint of the No Action Alternative are classified as Urban Land that has been
significantly changed from native soils and contains numerous impervious surfaces such as buildings and
pavement. No prime farmland was identified in this AVE. In-depth information regarding geology and
soils of the No Action Alternative can be found in Section 4.1.
4.12..1.4.3 Visual Character of the Community, Social, and Cultural Environments for the No Action
Alternative
The visual character of the community, social, and cultural environments of the No Action Alternative
viewshed is based on the human use and development of the landscape. The truck route for the No
Action Alternative passes through the residential neighborhood of Allentown, and borders the Tukwila
Community Center on the north and west. The Tukwila Community Center is an important gathering
place for social and recreational activities.
4.1.2..1..4.4 No Action Alternative Key View
The Key View for the No Action Alternative is located on South 124th Street. Although there are higher
vantage points within the AVE from which it may be possible to get a wider view, this Key View was
determined because of the truck route's proximity to residential structures and the Tukwila Community
Center, which is an important social and community fixture. This Key View was intended to simulate a
static view from a pedestrian standing on the sidewalk outside of the Tukwila Community Center (see
Figure 4.12-1).
4.12.1.5 Alternative 2: Airport Way South
The study area of Alternative 2 consists of the proposed Alternative 2 footprint, the truck route for this
alternative, and a half -mile buffer, Figure 4.12-2. The half -mile buffer was used for visual analysis
because this distance falls within the FHWA's 'foreground' range. Alternative 2 would entail constructing
roads and a new truck yard for the BNSF intermodal facility. A detailed description of the Alternative 2
300
components and routes are provided in Section 3.4, and detailed descriptions of the affected areas of
land use, recreational areas, and shoreline use are provided in Section 4.4.
301
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4.1.2..1..5.1. Visual Character of Land Use and Landform for Alternative 2.
The AVE for Alternative 2 is comprised of industrial, residential, infrastructure, and commercial areas
interspersed with green spaces such as parks, and trails. The land use in the northern portion of the AVE
is dominated by commercial and industrial zones within the City of Tukwila. The area is highly developed
with infrastructure such as highways and train tracks, with the central portion of the AVE located within
a heavy manufacturing Industrial center zone. Allentown residential areas in the south-central portion of
the AVE, and residential areas in Burien, Seattle, and King County.
The AVE for Alternative 2 overlaps with the land use zoning areas listed in Table 4.12-3.
Table 4.12-.3 Land Use Zoning within the AVE for Alternative 2
Municipality
Land Use Zoning
City of Tukwila
•
Heavy Industrial (HI)
•
Light Industrial (LI)
•
Manufacturing Industrial Center/ Heavy (MIC/H)
•
Manufacturing Industrial Center/ Light (MIC/L)
•
Commercial Light Industrial (CLI)
•
Residential Commercial Center (RCC)
•
Office (0)
•
High Density Residential (HDR)
•
Medium Density Residential (MDR)
•
Low Density Residential (LDR)
City of Seattle
•
Industrial and Maritime Zone (MML U/65),
(MML U/85)
•
Neighborhood Residential (NR1), (NR2), (NR3)
•
Multi -family Residential (LR1 (M))
•
Mixed Zone Residential/Commercial (C2-75 (M))
•
Mixed Zone Residential/Commercial (NCI-40
(M))
City of Burien
•
Community Commercial (CC-1), (CC-2)
•
Residential Multi -Family (RM-12), (RM-18), (RM-
24),(RM-48)
•
Residential Single Family (RS-7,200)
King County
•
Urban Residential (R-6), (R-8), (R-18)
Sources: (King County 2024a; King County 2024b, City 2024a; City 2024b; City of Seattle 2024a; Burien 2019)
A key landform centrally located in the AVE of proposed Alternative 2 is Duwamish Hill. Duwamish Hill is
a glacial remnant (Forterra 2025). Due to its elevated position above the Duwamish River, the hill offers
an excellent vantage point within the valley (City 2024d). There is a smaller hill north of Duwamish Hill
that is within the Seattle Police Athletic Association (SPAA) firearms training facility. This feature has
been altered from its natural form to support the activities within this industrial -zoned area, such as
using the hill as a target range backstop or as source of gravel for creating berms within the facility.
4.1.2..1..5.2. Visual Character of the Natural Environment for Alternative 2.
The central ecological features for Alternative 2 are the Duwamish River, which transects the AVE from
the south to northwest, and Duwamish Hill. Tukwila Residential areas located in a south-central corridor
of the Alternative 2 AVE from South 113th Street to South 125th Street. This residential corridor includes
Duwamish Hill Preserve at the north, the Duwamish River, the Green River Trail, parks, and open spaces.
303
Within the industrially zoned areas, there are two parks that face each other across the Duwamish River
(Cecil Moses Memorial Park and North Winds Weir), and the SPAA firearms training facility.
The AVE for Alternative 2 overlaps with the green spaces and recreational areas listed in Table 4.12-4.
Table 4.12 4 Recreational Areas within the AVE for Alternative 2
Municipality
Recreational Areas
City of Tukwila
•
Cecil Moses Memorial Park
•
North Winds Weir
•
Duwamish River
•
Green River Trail
•
Tukwila Community Center
•
Duwamish Park
•
Codiga Park
City of Seattle
•
East Duwamish Greenbelt
•
Benefit Playground
City of Burien
•
Rainier Golf & Country Club
•
Hilltop Park
King County
•
N/A
Sources: (City 2024d; King County 2022b)
The soils in the footprint of Alternative 2 are classified as Urban Land that has been significantly changed
from native soils. No prime farmland was identified in this AVE. In-depth information regarding geology
and soils of Alternative 2 can be found in Section 4.1.
The footprint of Alternative 2 has the highest percentage of vegetative landcover compared to the other
alternatives because the area of the proposed truck yard would be constructed on the grounds of the
current SPAA which is primarily open space. The SPAA grounds have a mix of landscaped and maintained
vegetation and natural tree, shrub, and grass growth. The landcover classes for Alternative 2 are
described in Table 4.12-5.
Table 4.12-5 Landcover type and percentage of the Alternative 2 Footprint
Landcover Class
Area within Project
Footprint (acres)
Percentage of
Alternative footprint
Bare Soil
2.23
7.9%
Grass/Low-Lying Vegetation
11.84
42.0%
Impervious Surfaces
2.98
10.6%
Open Water [Duwamish River]
0.15
0.5%
Tree Canopy
10.75
38.2%
Unclassified (Unincorporated King County)
0.23
0.8%
Total
28.18
100
Refer to Section 4.2 for full landcover context
4.12..1.5.3 Visual Character of the Community, Social, and Cultural Environments for Alternative 2.
The visual character of the community, social, and cultural environments of the Alternative 2 viewshed
is based on the human use and development of the landscape. The truck traffic for Alternative 2 would
be routed through industrial, commercial, and manufacturing zones. The proposed truck yard for
Alternative 2, however, would be constructed approximately 200 feet north of the Duwamish Hill
304
Preserve. The Duwamish Hill Preserve is an important cultural area in Tukwila. Duwamish Hill Preserve is
managed as a public open space preserve dedicated to the conservation and enhancement of its rich
Native American cultural history, ecological importance and community impact (City 2024d).
Additionally, the hill is associated with the southern Puget Sound Salish oral tradition in the stories
collectively known as the "Epic of the Winds" (Forterra 2025).
4.1.2..1..5.4 Alternative 2. Key View
The Key View for Alternative 2 is located on the north face of Duwamish Hill at approximately 140 feet in
elevation overlooking the SPAA where the truck yard would be built for this alternative. This Key View
was chosen for two main reasons. First, this location and bearing was chosen because of its elevation
which offers a significant vantage point of the proposed alternative footprint area. Secondly,
recreational, cultural, and community users of the preserve would be the most impacted by the changes
to the viewshed that would result from Alternative 2. This Key View intends to simulate a static view
from a pedestrian standing on the closest overlook to the proposed truck yard of Alternative 2 (see
Figure 4.12-3).
305
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4.12.1.66 Alternative 3B: Improvements to 48th Place South
The affected environment of the Alternative 3B consists of the proposed Alternative 3B footprint, the
truck route for this alternative, and a half -mile buffer, Figure 4.12-4. The half -mile buffer was used for
visual analysis because this distance falls within the FHWA's 'foreground' range. Alternative 3B would
entail constructing a bridge across the Duwamish River and a new truck entrance to the BNSF
intermodal facility. A detailed description of the Alternative 3B components and routes are provided in
Section 3.4, and detailed descriptions of the affected areas of land use, recreational areas, and shoreline
use are provided in Section 4.4.
307
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4.1.2..1..6.1. Visual Character of Land Use and Landform for Alternative 3B
The AVE for Alternative 3B is comprised of residential, industrial, infrastructure, office, and commercial
areas interspersed with green spaces such as parks, and trails. Compared to the other alternatives, the
AVE for Alternative 3B has the least overlap with heavy industrial or heavy manufacturing zones. The
land use in the AVE is strongly characterized as residential; however, the proposed construction would
primarily occur in Commercial Light Industrial and Heavy Manufacturing Industrial Centers. The truck
traffic for this alternative would not be routed through residential areas; it would be relegated to light
industrial areas, highways, and interstates.
The AVE for Alternative 3B overlaps with the land use zoning areas listed in Table 4.12-6.
Table 4..12-6 Land Use Zoning within the AVE for Alternative .3B
Municipality
Land Use Zoning
City of Tukwila
•
Heavy Industrial (HI)
•
Light Industrial (LI)
•
Manufacturing Industrial Center/ Heavy (MIC/H)
•
Manufacturing Industrial Center/ Light (MIC/L)
•
Commercial Light Industrial (CLI)
•
Residential Commercial Center (RCC)
•
Regional Commercial Mixed Use (RCM)
•
Mixed Use Office (MUO)
•
Regional Commercial (RC)
•
Office (0)
•
Neighborhood Commercial Center (NCC)
•
High Density Residential (HDR)
•
Medium Density Residential (MDR)
•
Low Density Residential (LDR)
King County
•
Neighborhood Business with Property -specific
development standards (NB-P)
•
Urban Residential (R-6), (R-24)
•
Urban Residential with Property -specific
development standards (R-24-P)
Sources: (King County 2024a; King County 2024b, City 2024b; City 2024a)
4.1.2..1..6.2. Visual Character of the Natural Environment for Alternative 3B
The central ecological features for Alternative 3B are the Duwamish River, which transects the AVE from
the southeast to north, and Codiga Park. Codiga Park is located on a bend of the Duwamish River and
would be adjacent to the new bridge for proposed Alternative 3B. The Duwamish River is a destination
for local sport fishers, and Codiga Park offers convenient river access for this activity. The park is a
partially restored tidal wetland that provides shelter and food for wildlife like ospreys, great blue
herons, bald eagles, and juvenile salmon (City 2024d).The AVE for Alternative 3B overlaps with the green
spaces and recreational areas listed in Table 4.12-7.
309
Table 4..12-7 Recreational Areas within the AV
Municipality
Recreational Areas
City of Tukwila
•
Duwamish River
•
Green River Trail
•
Tukwila Community Center
•
Codiga Park
•
Riverton Park
•
Riverton Mini Park
•
Southgate Park
•
Tukwila Pool
•
Macadam Wetlands and Winter Garden
•
Joseph Foster Memorial Park/ Lee Philips Park
•
Foster Golf Links
•
57' Avenue South Mini Park
•
Pamela Drive Open Space
King County
•
West Skyway Natural Area
Sources: (City 2024d; King County 2022b)
The soils in the footprint of Alternative 3B are classified as Urban Land and Urban Land-Alderwood
complex (12-35 percent slopes) that have been significantly changed from native soils and contain
numerous impervious surfaces such as buildings and pavement. No prime farmland was identified in this
AVE. In-depth information regarding geology and soils of Alternative 3B can be found in Section 4.1.
The footprint of Alternative 3B would be primarily within areas of existing disturbance and impervious
surfaces (Table 4.12-8).
Table 4..12.8 Landcover type and percentage of the Alternative .3B Footprint
Landcover Class
Area within Project
Footprint (acres)
Percentage of
Alternative footprint
Bare Soil
0.02
0.7%
Grass/Low-Lying Vegetation
0.14
4.9%
Impervious Surfaces
2.19
76.3%
Open Water [Duwamish River]
0.11
3.8%
Tree Canopy
0.41
14.3%
Unclassified (Unincorporated King County)
0
0.0%
Total
2.87
100
Refer to Section 4.2 for full landcover context
4.1.2..1..6.3 Visual Character of the Community, Social, and Cultural Environments for Alternative 3B
The visual character of the community, social, and cultural environments of the Alternative 3B viewshed
is based on the human use and development of the landscape. The truck traffic for Alternative 3B would
be routed through Commercial Light Industrial and Manufacturing Industrial Center/ Heavy zoned areas.
While the truck traffic would not be physically within residential areas, it would be visible from locations
along the Green River Trail and from the southeast side of Codiga Park. The Green River Trail is adjacent
to commercial and light industrial activities throughout most of Alternative 3B with views across the
river of residential and recreational areas.
310
4.1.2..1..6.4 Alternative 3B Key View
Several Key Views were considered for Alternative 3B, as shown in Figure 4.12-5. The view from Trail 1
was selected as the Key View for this alternative because of its proximity to the proposed construction
of Alternative 3B and for the wider viewshed that this position and bearing permitted compared to the
other locations. The 'Trail 1' location was also selected to be the Key View for this alternative because
the viewshed of users of the Green River Trail would be most affected by the proposed bridge. Figure
4.12-6 represents the vantage of the Alternative 3B Key View; this image intends to simulate a static
view from a pedestrian approaching the proposed bridge.
311
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4.12.1.7 Alternative 4: New Bridge from SR 900 (MLK.Jr Way) to South 129th Street
The affected environment of the Alternative 4 consists of the proposed Alternative 4 footprint, the truck
route for this alternative, and a half -mile buffer, Figure 4.12-7. The half -mile buffer was used for visual
analysis because this distance falls within the FHWA's 'foreground' range. Alternative 4 would entail
constructing new truck entrance at the south end of the BNSF intermodal facility, new access roads
connecting SR 900 to South 129th Street at the south end of the alternative, and connecting SR 900 to 1-5
towards the north end of the alternative. A detailed description of the Alternative 4 components and
routes are provided in Section 3.4, and detailed descriptions of the affected areas of land use,
recreational areas, and shoreline use are provided in Section 4.4.
314
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4.12..1.7.1 Visual Character of Land Use and Landform for Alternative 4
The AVE for Alternative 4 is comprised of residential, industrial, infrastructure, office, commercial, and
mixed -use areas interspersed with green spaces such as parks, and trails. The southwest side of
proposed Alternative 4's truck route primarily borders Manufacturing Industrial Center/ Heavy zones;
whereas the northeast side of the truck route primarily borders residential areas. Truck traffic for
proposed Alternative 4 would be routed through industrial, commercial, and manufacturing zones, and
through residential zones and green spaces. The proposed footprint for the Alternative 4 truck access
into the BNSF facility would be constructed on land currently zoned as low density residential where
there is an occupied residence.
The AVE for Alternative 4 overlaps with the land use zoning areas listed in Table 4.12-9.
Table 4.12-9 Land Use Zoning within the AVE for Alternative 4
Municipality
Land Use Zoning
City of Tukwila
•
Heavy Industrial (HI)
•
Light Industrial (LI)
•
Manufacturing Industrial Center/ Heavy (MIC/H)
•
Manufacturing Industrial Center/ Light (MIC/L)
•
Commercial Light Industrial (CLI)
•
Residential Commercial Center (RCC)
•
Office (0)
•
High Density Residential (HDR)
•
Medium Density Residential (MDR)
•
Low Density Residential (LDR)
•
Regional Commercial Mixed Use (RCM)
City of Seattle
•
Industrial and Maritime Zone (MML U/65)
•
Neighborhood Residential (NR1), (NR2), (NR3)
•
Multi -family Residential (LR1 (M))
•
Mixed Zone Residential/Commercial (NCI-40
(M))
King County
•
Neighborhood Business (NB)
•
Neighborhood Business with Property -specific
development standards (NB-P)
•
Urban Residential (R-6), (R-8), (R-12), (R-24)
•
Urban Residential with Property -specific
development standards (R-12-P), (R-24-P), (R-48-
P)
•
Urban Residential with Property -specific
development standards and Special District
Overlay (R-48-P-SO)
Sources: (King County 2024a; King County 2024b; City of Seattle 2024a; City 2024a; City 2024b)
4.12..1.7.2. Visual Character of the Natural Environment for Alternative 4
The portion of the AVE within the city of Tukwila is heavily developed for industrial and commercial
uses. The central ecological features for Alternative 4 are Duwamish River, which transects the AVE from
the south to northwest, and the green space areas on the east and northeast side of the proposed new
access roads. Heavy industrial/ manufacturing and commercial zones run through the core of Alternative
4's AVE, following the direction of the Duwamish River valley. Residential areas include the
316
neighborhood of Allentown in the west -central area of the AVE, and the majority of the AVE to the
south, east, and northeast of Alternative 4's proposed truck route.
The proposed access area for Alternative 4 is adjacent to Codiga Park and the West Skyway Natural
Area. Other green spaces and recreational areas that overlap with the AVE for Alternative 4 are listed in
Table 4.12-10.
Table 4.12-10 Recreational Areas within the AVE
`iv
4
Municipality
Recreational Areas
City of Tukwila
•
Duwamish River
•
Green River Trail
•
Tukwila Community Center
•
Duwamish Park
•
Codiga Park
•
Foster Golf Links
•
57' Avenue South Mini Park
•
Pamela Drive Open Space
King County
•
Skyway Farms
•
West Skyway Natural Area
Sources: (City 2024d; King County 2022b)
The soils in the footprint of Alternative 4 are classified as Alderwood-Everett-Urban Land complex,
Urban Land, Urban Land-Alderwood complex, and Urban Land-Beausite complex. No prime farmland
was identified in this AVE. In-depth information regarding geology and soils of Alternative 4 can be
found in Section 4.1.
The footprint of Alternative 4 would be both within areas of existing disturbance and areas that would
require ground disturbance in treed or vegetated areas (Table 4.12-11).
Table 4.12-11 Landcover type and percentage of the Alternative 4 Footprint
Landcover Class
Area within Project
Footprint (acres)
Percentage of Alternative
footprint
Bare Soil
0.03
0.5%
Grass/Low-Lying Vegetation
0.53
8.0%
Impervious Surfaces
1.73
26.3%
Open Water
0.00
0.0%
Tree Canopy
1.84
28.0%
Unclassified (Unincorporated King County)
2.46
37.4%
Total
6.59
100.2
Note: Total percentage is greater than 100% due to rounding individual percentages. Refer to Section 4.2.forfull
landcover context
4.12..1.7.3 Visual Character of the Community, Social, and Cultural Environments for Alternative 4
The visual character of the community, social, and cultural environments of the Alternative 4 viewshed
is based on the human use and development of the landscape. Along with Codiga Park and the
Duwamish River/Green River Trail, the Tukwila Community Center is an important gathering place for
social and recreational activities.
317
4.12..1.7.4 Alternative 4 Key Views
Proposed Alternative 4 has two Key Views, one in the south portion, and one in the north. Key View A is
located on 51" Street Place South, with a northern bearing which viewshed includes the area of the
proposed new truck entrance area. Key View B is on Martin Luther King Jr. Way South, on the overpass
that crosses 1-5. The bearing for this Key View is east towards the area of the proposed new truck access
road. These Key Views were chosen because they would have the best vantage points of new
construction area, where construction and operation impacts would have the most effect on visual
resources. Both Key Views for Alternative 4 are analyzed as static Key Views ; Key View A simulates the
standing view of a pedestrian, and Key View B is a static position on an elevated roadway looking
towards a vegetated hill where construction would occur (Figure 4.12-7).
4.12.2 Relevant Plans Policies and Regulations
The relevant plans, policies, regulations, and guidance consulted when analyzing the potential impacts
of the proposed Alternatives are described in Table 4.12-12:
Table 4..12-.12 Relevant Plans, Policies, and Regulations
I aw, Regulation, or Guidance
Description
Federal
NEPA 23 CFR 771
According to the CEQ implementing regulations,
environmental analysis is to consider impacts on urban
quality, historic and cultural resources, and the design of
the built environment.
Guidelines for the Visual Impact Assessment of
Highway Projects (FHWA-HEP-15-029)
These guidelines respond to NEPA and other federal
requirements related to the visual character of lands.
Section 4(f) of the Department of
Transportation Act of 1966. Chapters 400, 455,
and 457.
This act declared the national policy to make special
effort to preserve the natural beauty of the countryside
and public park and recreation sites, wildlife and
waterfowl refuges, and historic sites.
Section 106 of the National Historic
Preservation Act (1976)
This act requires the definition of criteria of adverse
effects to include analysis of the introduction of visual,
atmospheric, or audible elements that diminish the
integrity of the property's significant historic features.
State
State Environmental Policy Act (SEPA) WAC
197-11 and WAC 468-12
SEPA requires that all major actions sponsored, funded,
permitted, or approved by state and/or local agencies
undergo planning to ensure environmental
considerations such as impacts related to aesthetics and
visual quality are given due weight in decision making.
Growth Management Act (GMA)
Requires all cities and counties in Washington to adopt
development regulations that protect critical areas,
including shorelines and their visual access.
318
Law, Regulation, or Guidance
Description
Washington State Shoreline Master Program.
WAC 173-26-191
Shoreline master programs are both planning and
regulatory tools. Master programs balance and integrate
the objectives and interests of local citizens, they address
the full variety of conditions on the shoreline, and they
consider and, where necessary to achieve the objectives
of chapter 90.58 RCW, influence planning and regulatory
measures for adjacent land. Master programs address
conditions and opportunities of specific shoreline
segments by classifying the shorelines into "environment
designations" as described in WAC 173-26-211.
Local
City of Tukwila Comprehensive Plan (2015)
A comprehensive plan is a broad statement of community
goals and policies that direct the orderly and coordinated
physical development of a city into the future. It reflects
current community goals and needs, anticipates change,
and provides specific guidance for future legislative and
administrative actions. It reflects the results of public
involvement, technical analysis, and the judgment of
decision makers.
King County Critical Areas Ordinance (King
County Code [KCC] 21A)
This ordinance was developed under the directives of the
GMA to designate and protect critical areas and to assist
in conserving the value of property, safeguarding the
public welfare, and providing protection for these areas.
King County Open Space Plan (2022)
This plan provides a framework guiding King County in
the planning, development, stewardship, and
management of its complex system of 200 parks, 175
miles of regional trails, and 206,000 acres of open space.
City of Tukwila Environmentally Critical Areas
TMC 18.45
The purpose of TMC Chapter 18.45 is to protect the
environment, human life and property; to designate and
classify ecologically critical areas including but not limited
to regulated wetlands and watercourses and geologically
hazardous areas and to protect these critical areas and
their functions while also allowing for reasonable use of
public and private property. These regulations are
prepared to comply with the Growth Management Act.
Tukwila Zoning Code Title 18 TMC
This code encourages land use decision making, promotes
orderly development, provides adequate public facilities
and services, promotes public safety by regulating
development of lands containing physical hazards, and
minimizes adverse environmental impacts of
development.
City of Seattle Environmentally Critical Areas
SMC 25.09
The purpose of Chapter 25.09 to provide for and promote
the health, safety and welfare of the general public, and
to not create or otherwise establish or designate any
particular person, or class, or group of persons who will
or should be especially protected or assisted by the terms
or provisions.
319
l aw, Regulation, or Guidance
Description
Seattle Zoning Code Title 23 SMC
This code encourages land use decision making, promotes
orderly development, provides adequate public facilities
and services, promotes public safety by regulating
development of lands containing physical hazards, and
minimizes adverse environmental impacts of
development.
Zoning, City of Burien Municipal Code (BMC)
This code encourages land use decision making, promotes
Title 19
orderly development, provides adequate public facilities
and services, promotes public safety by regulating
development of lands containing physical hazards, and
minimizes adverse environmental impacts of
development.
4.12.3 Methodology
The area of visual effect (AVE) is determined by the physical constraints of the environment and the
physiological limits of human sight (FHWA 2015). The common constraints when determining the visual
analysis for the alternatives of the proposed Project are landform, land cover, location (topographic
position), proximity, and light.
Landform provides perspective for a viewer, and it obscures views. Land cover is critical for determining
the physical constraints of the environment. Vegetation and structures can become obstacles obscuring
views, and the level of regional development and human activities in the area inform the perceived
impact of new construction. In addition to physical constraints of the environment, location, proximity
and light are instrumental in defining the physiological limits of what viewers can see.
Location is defined as the topographic position. Key Views are usually selected for a project because
they are either critical or representative of the visual character of either the environment or the project.
Description of the Key Views for each alternative are found under the Affected Environment, Section
4.12.1. Proximity of the viewer to an object is defined using three distinct distance zones: foreground,
middle ground, or background. Because of the topography, extensive level of development in the study
areas, and because the engineering designs for the proposed alternatives are only preliminary and for
conceptual purposes, the areas of visual effects have been defined as a half -mile buffer around each
alternative and its proposed truck route. The FHWA defines the foreground as being 0.25 to 0.5 mile
away from the viewer (FHWA 2015); Key View locations and bearings were selected for each proposed
alternative to be within the foreground proximity, and to be in a position where the landform and land
cover would provide the best vantage point for critical analysis of the proposed actions.
Light is another factor that can alter viewer perception of objects. For this proposed Project, the largest
perception shift for the alternatives would be between night and day, and the analysis for each
alternative considers the visual concerns that may shift with the level of natural light. The nearest
certified International Dark Sky Park to the proposed Project would be Cottonwood Canyon State Park in
Oregon (DarkSky 2024). Because this designated Dark Sky Park is approximately 165 miles from the
proposed Project, the alternatives will not be analyzed for their effect on Dark Sky resources.
There are three types of viewsheds that could be considered for viewshed analysis: static, dynamic, and
restricted. Static viewsheds are based only on landform, and land cover plays a major role in restricting
320
viewsheds. Dynamic viewsheds are more complicated and are based on what travelers on a road may
see. Due to the preliminary nature of the engineering designs and the landform, land cover, and
extensive development of the study areas, only static or restricted viewsheds will be discussed in this
analysis.
For the proposed Project, character compatibility and sensitivity are used to determine the degree of
impacts to aesthetics and visual resource. The FHWA's Visual Character Compatibility Matrix will be used
to determine the compatibility of impact for each alternative; the matrix is summarized below in Table
4.12-13.
Table 4.12-1.:3 F'HWA Visual Character Compatibility Matrix
AVE Visual Character
Natural Environment Cultural Environment Project Environment
Project Visual Character
Project Scale
Is the project scale compatible or incompatible with the visual character of the
natural, cultural, and project environments? Will the project scale contrast or not
contrast with these environments?
Project Form
Is the project form compatible or incompatible with the visual character of the
natural, cultural, and project environments? Will the project form contrast or not
contrast with these environments?
Project Materials
Are the project materials compatible or incompatible with the visual character of
the natural cultural and project environments? Will the project materials contrast or
not contrast with these environments?
Project Visual Character
In summary, will the project's visual character be compatible or incompatible with
the visual character of the existing natural, cultural, and project environments? Will
the project's visual character contrast or not contrast with these environments? Has
the memorability or vividness of the landscape or project area been altered? How
has it changed?
Source: (FHWA 2015)
Additionally, viewer sensitivity is analyzed for each proposed alternative by using the FHWA's Impacts to
Visual Quality Matrix (Table 4.12-14):
Table 4.12-.14 Impacts to Visual Quality Matrix
Viewer Sensitivity
Exposure Awareness
Impacts to Visual Compatibility
Natural Harmony
How have changes in exposure and awareness affected the experience of natural
harmony in the AVE? Have changes caused by the project been adverse, beneficial,
or neutral to the experience of natural harmony in the AVE?
Cultural Order
How have changes in exposure and awareness affected the experience of cultural
order in the AVE? Have the changes caused by the project been adverse, beneficial,
or neutral to the experience of cultural order in the AVE?
Project Coherence
How have changes in exposure and awareness affected the experience of project
coherence in the AVE? Have the changes caused by the project been adverse,
beneficial, or neutral to the experience of project coherence in the AVE?
Visual Quality
How have changes in exposure and awareness affected the experience of overall
visual quality in the AVE? Have the changes caused by the project been adverse,
beneficial, or neutral to the experience of the overall visual quality in the AVE?
Source: FHWA 2015)
321
The visual attributes of the proposed Project's major structures and common features are described and
documented below in relation to the criteria outlined in this methodology.
4.12.4 Impacts Analysis
In this subsection, the proposed Alternatives are analyzed in turn in respect to Visual Resources and
Aesthetics. The impacts are evaluated by using the definitions listed in Table 4.12-15.
Table 4.12-15 Impact Magnitude and Description
Magnitude of Impact
Description
No Impact
The proposed Project would be fully consistent with the intent of applicable visual
resources and aesthetics plans and policies.
Minor
The proposed Project would result in short-term temporary impacts, or minimal long-
term impacts to visual resources and aesthetics.
Moderate
The proposed Project would result in long-term or permanent impacts to aesthetics or
visual resources, but mitigation can be applied to reduce the impact to be less than
significant.
Significant
The proposed Project would cause long-term, permanent, or irreversible inconsistencies
with applicable aesthetics or visual resources plans and policies, or to the natural,
cultural, or community visual character of the AVE .
4.12..4.1 No Action Alternative
4.12..4.1.1 Construction Impacts
Construction impact analysis is not applicable because the No Action Alternative is the current
operating condition of the BNSF Intermodal Facility and the truck transportation route.
4.1.2..4.1..2. Operations Impacts
The continuing operation of the No Action Alternative would have a moderate impact on visual
resources. In terms of project scale and visual character, the presence of an industrial zone is not
consistent with the visual character of the cultural environment along South 124th Street which is zoned
for residential and recreational areas. Residents have frequent exposure to the sight of large trucks
along South 124th Street which disrupts the natural harmony of the visual characteristics of the
residential and recreational aspects of the AVE. Headlights from frequent truck traffic at night would
continue to have a negative impact to residents along South 124th Street. The frequent exposure of
heavy vehicles in this area has a negative impact on the overall visual quality in the No Action
Alternative.
4.12..4.2. Alternative 2: Airport Way South
4.12..4.2.1 Construction Impacts
Construction of proposed Alternative 2 would create moderate negative changes in visual contrast and
scenic quality in the AVE. Construction would require leveling and other groundwork which entails
removing local vegetation to build roadways, an overpass with abutments, and an approximately 26-
acre, paved, truck staging area for the BNSF facility. Temporary infringements to the current aesthetics
would include fugitive light from portable sources, particularly at night. Potential mitigation for this
impact is described in Section 4.12.5. The land where Alternative 2 would be built is zoned as a heavy
manufacturing and industrial center. The project scale and form are visually compatible with the zoned
land use, but construction would negatively impact the current visual character of the landform and
natural environment.
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4.1.2..4.2..2. Operations Impacts
Alternative 2 would have a significant negative impact on the visual character of the AVE. The greatest
visual changes for Alternative 2 would result from the alteration of the landform from a hill to a level
area for truck use. Structures associated with the new BNSF access roads and truck yard, such as the
tunnel and abutment, retaining walls, and the one-story entrance building within the proposed BNSF
truck yard would be built, removing topography and vegetation and replacing it with paved surfaces.
The proposed Project would change the form, line, color and texture elements of the current visual
resources.
The proposed Alternative 2 would be located on land that has been zoned as Manufacturing Industrial
Center/ Heavy (MIC/H) which allows for widescale development. The area where the truck yard for the
BNSF facility would be sites is currently used as a firearms training center for the SPAA. Even though the
area is zoned as heavy industrial, the SPAA facility grounds are landscaped, and the shooting ranges are
bordered by a mix of native and cultivated trees and shrubs that create wind breaks and visual
screening. The current visual characteristics has park -like qualities such as a barbeque pavilion, a
horseshoe pit, and open spaces. Alternative 2 would create a strong contrast to the current visual
character of the AVE during the day and possibly at night. The design of the proposed truck yard is still in
the conceptual stages, but parking lot or safety lighting, if included in the design, could create a strong
nighttime contrast to the current viewshed.
Potential mitigation for impacts relating to Alternative 2 are described in Section 4.12.5.
4.12..4.3 Alternative 3B: Improvements to 48th Place South
4.12..4.3.1 Construction Impacts
Construction of proposed Alternative 3B would create minor negative changes in visual contrast and
scenic quality in the AVE. Construction for this alternative would be temporary and infringements to the
current aesthetics would include disturbance of some existing vegetation and the generation of fugitive
light from portable sources, particularly at night. Potential mitigation for this impact is described in
Section 4.12.5.
4.1.2..4.3.2. Operations Impacts
Alternative 3B would have a moderate negative impact on the visual character of the AVE that, through
mitigation, could be reduced to minor impacts. The greatest visual changes for Alternative 3B would
result from the presence of a new bridge crossing the Duwamish River, connecting the Gateway
Business Center to the south end of the BNSF intermodal facility. Figure 4.12-8 is a digital rendering of
how the Alternative 3B bridge could appear to viewers from the Key View on the Green River Trail. The
"Beach" view in Figure 4.12-5 was not used as the Key View for Alternative 3B because field teams
determined that the new bridge would not be visible from that location in the bend of the river. Because
a preferred alternative has not yet been selected for the proposed Project, the design and specifications
of the bridge shown in Figure 4.12-8 are not based on detailed engineering plans; the rendering is for
conceptual purposes only.
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1U
From the digital rendering, the scale of the proposed bridge is compatible with the visual character of
the Project Environment. The bridge design and size would be consistent with other bridges within the
Alternative 3B AVE, and would be consistent with the visual character of commercial and industrial
areas. The Allentown Bridge also spans the Green River Trail and Duwamish River and truck traffic
travels adjacent to a cultural resource: the Tukwila Community Center, a popular hub for recreation and
community activities. The bridge proposed for Alternative 3B would fit similar characteristics to the
Allentown Bridge. However, unlike the Allentown Bridge and the Tukwila Community Center, the bridge
for Alternative 3B would provide a physical separation of truck traffic from user access to Codiga Park.
At this early stage of design, lighting needs on or under the bridge for safety on the Green River Trail is
unknown. New lighting at this location could have a negative effect on the nighttime aesthetics.
Potential mitigation for impacts relating to Alternative 3B are described in Section 4.12.5.
4.12..4.4 Alternative 4: New Bridge from SR 900 (MLKJr Way) to South 129th Street
4.12..4.4.1 Construction Impacts
Construction of proposed Alternative 4 would create moderate negative changes in visual contrast and
scenic quality in the AVE. Construction would require leveling, retaining walls, and other ground work
which entails removing local vegetation to build roadways. Temporary infringements to the current
aesthetics would include fugitive light from portable sources, particularly at night. Potential mitigation
for this impact is described in Section 4.12.5. The land where Alternative 4 would be built is zoned as a
high and low -density residential and green space (West Skyway Natural Area). The project scale and
form are not visually compatible with the zoned land use, and construction would negatively impact the
current visual character of the landform and natural environment.
4.1.2..4.4.2. Operations Impacts
Alternative 4 would have a significant negative impact on the visual character of the AVE. The greatest
visual changes for Alternative 4 would result from the alteration of the land use and of the landform in
the northern portion of the alternative. Structures associated with the new BNSF access roads and truck
access, such as road exit/enter ramps, retaining walls, and the one-story entrance building within the
proposed BNSF truck access area would be built, removing topography and vegetation and replacing it
with paved surfaces or cut -back areas. The proposed Project would change the form, line, color and
texture elements of the current visual resources.
The southern portion of proposed Alternative 4 would be located on land that has been zoned as low -
density residential and green space. The area where the truck yard for the BNSF facility would be sited is
currently the location of an occupied residence. Removing the residence to construct and operate a new
truck entrance and noise wall would create a strong visual contrast to the current visual character of the
AVE during the day and possibly at night. The design of the proposed truck entrance is still in the
conceptual stages, but parking lot or safety lighting, if included in the design, could create a strong
nighttime contrast to the current viewshed.
Potential mitigation for impacts relating to Alternative 4 are described in Section 4.12.5.
412.4.5 Summary of Operational Impacts per Alternative
A summary of the impacts for Visual Resources and Aesthetics for the proposed Project Alternatives is
presented in Table 4.12-16.
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Table 4..12 ..1.6 Impact Summary Table
Alternative
Phase
Magnitude of Impact to
Visual Resources
No Action
Construction
N/A
Operation
Moderate
2
Construction
Moderate
Operation
Significant
3B
Construction
Minor
Operation
Moderate
4
Construction
Moderate
Operation
Significant
4.12.5 Mitigation Measures
4.12..5.1 No Action Alternative
The No Action Alternative represents the current operating conditions of the BNSF-related heavy vehicle
traffic through the Allentown neighborhood of Tukwila. Feasible mitigation measures are presented in
this EIS as Alternatives 2, 3B, and 4.
4.12..5.2. Alternative 2: Airport Way South
Alternative 2 would have adverse impacts on the landform, visual experience, and likely nighttime
lighting. Possible mitigation could include minimization measures such as using downward
directional/shaded lighting during construction and operation. For parking lot lighting, further
minimization could be accomplished by using motion -activated lights so that illumination is not
constant.
The views of the proposed truck yard from the Key View could be minimized by including an attractive
security wall on the south and west sides of the truck yard, combined with tall and dense vegetation
that would obscure the view of the truck yard from the Key View. For additional minimization, berms
can be formed around the outside of the south and west sides of the truck yard that mimic natural hills.
Tall and dense landscaping on these features would result in greater minimization of negative impacts to
the viewshed.
4.12..5.3 Alternative 3B: Improvements to 48tt' Place South
The Moderate impacts to Visual Resources from implementing Alternative 3B would occur as a result of
constructing a new bridge across the Duwamish River. This impact could be mitigated with
compensation such as designing a more aesthetically pleasing structure with enhanced design rather
than using a more utilitarian design. An attractive bridge design could become an architectural landmark
for the City that adds visual interest rather than detracts from the surroundings.
Negative visual impacts can also be mitigated with minimization measures such as replacing vegetation
that was removed with new shrubs and trees that would obscure views of the bridge from the Green
River Trail and from Codiga Park. If lighting is part of the new bridge design, nighttime visual impacts can
be mitigated with the use of downward, shaded, and motion -activated lighting.
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4.12..5.4 Alternative 4: New Bridge from SR 900 (MLK.Jr Way) to South 129th Street
The impacts to Visual Resources for Alternative 4 would be significant. Potential mitigation for the
impacts could include minimization measures such as constructing attractive, rather than solely
utilitarian, noise walls and retaining walls, establishing landscaping that obscures constructed features,
and by using downward and shaded nighttime lighting.
4.12.6 Significant Unavoidable Adverse Impacts
The impacts analyzed for the Visual Resources and aesthetics section that were determined to be
Significant would be avoidable by selecting another Alternative. As there is no preferred alternative for
this analysis, the impacts must be weighed against each other equally rather than in relation to a
"standard". Each of the Alternatives presented in this analysis have trade-offs; they affect the resources
in different ways and to different degrees. The purpose of this Environmental Impact Statement is to
find an alternate solution to the current operating conditions of the traffic related to the BNSF facility. A
solution that will reduce truck traffic in residential and recreational areas could have potential impacts
on visual resources in other areas within Allentown.
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5 Culnul
at ve
n pacts
This section analyzes potential impacts from past, present, and reasonably foreseeable future actions
(RFFAs) combined with the Proposed Alternatives. A Preferred Action has not yet been decided upon for
the Allentown Truck Re-route Project, and as a result, the level of engineering design for the alternatives
reflects a conceptual stage. Thus, cumulative impacts to most resources are discussed qualitatively.
5.1 Methodollogy
The boundaries of the study areas vary by resource. Cumulative effects should be evaluated in terms of
the specific resource, ecosystem, and human community being impacted. To determine the size of the
study area, each environmental resource was analyzed to determine the extent to which the
environmental effect from the proposed alternatives could be reasonably detected and the geographic
area impacted was defined. The study areas boundaries are applied equally within each resource for
each of the proposed Alternatives.
Past, present, and RFFAs were identified within each study area as projects that could potentially
interact or have a close causal relationship with the proposed Alternatives. Present actions that are
considered include those that have existing and/or ongoing disturbance. Past and present actions are
included in the affected environment descriptions as they are part of the existing environment. RFFAs
are those actions that are scheduled for development within the Resource study areas from February
2025 through 2028.
5.1.1 Reasonably Foreseeable Future Actions (RFFA)
RFFAs identified within the resource study areas that were evaluated for their potential to affect the
cumulative impacts of the proposed Project are described in Table 5.1-1. The RFFAs described in Table
5.1-1 would all occur on previously developed land and would be located within existing road or utility
rights -of -way (ROW), and/or are in areas zoned for Industrial use (WSDOT 2025). Furthermore, all of the
RFFAs in Table 5.1 1 are actions that have been determined to fall under environmental Categorical
Exclusions (CE) (WSDOT 2025). In Washington, categorical exclusions are actions that federal agencies
have determined do not have significant adverse environmental impacts. These exclusions are defined
under 40 CFR 1508.4 and 23 CFR 771.117.
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5.2 Cumulative Impact Analysis
5.2.1 Geology and Soils
5.2.1.1 StudyArea Description
The study area for geology and soils includes the footprint for Alternatives 2, 3B, and 4. and the general
vicinity of the No Action Alternative.
5.2.1.2 Past, Present, and Reasonably Foreseeable Future Actions
The study area for geology and soils is highly developed from past and present actions and is primarily
comprised of Urban Soils and impermeable surfaces. The RFFAs within this study area have been
determined to not have any significant environmental impacts to geology and soils.
5.2.1.3 Cumulative Effects
5.2 1 3.1. No Action Alternative
Under the No Action Alternative, the proposed Project would not be developed and the associated
impacts to geology and soil resources would not occur. Because there would be no construction or new
disturbance of land, cumulative impacts to geology and soil resources under the No Action Alternative
would be less than those under the other alternatives. Cumulative impacts to this study area from past,
present, and RFFAs, including the 42nd Avenue South bridge replacement (TUK-62) are anticipated to be
minor, long-term, and localized.
5.2 1 3.2. Alternative 2.
Under Alternative 2, there would be moderate impacts from alterations to the surface geology,
topography, and soils. None of the RFFAs in Table 5.1 1 would occur within the Alternative 2 study area
for geology and soils. Therefore, cumulative impacts to the geology and soils study area from the past,
present, and RFFAs, combined with the actions proposed for Alternative 2, would be moderate,
permanent, and localized.
5.2 1 3.3 Alternative 3B
Under Alternative 3B, there would be moderate impacts from alterations to the surface geology,
topography, and soils. None of the RFFAs in Table 5.1 1 would occur within the Alternative 3B study area
for geology and soils. Therefore, cumulative impacts to the geology and soils study area from the past,
present, and RFFAs, combined with the actions proposed for Alternative 3B, would be moderate,
permanent, and localized.
5.2 1 3.4 Alternative 4
Under Alternative 4, there would be moderate impacts from alterations to the surface geology,
topography, and soils. None of the RFFAs in Table 5.1 1 would occur within the Alternative 4 study area
for geology and soils. Therefore, cumulative impacts to the geology and soils study area from the past,
present, and RFFAs, combined with the actions proposed for Alternative 4, would be moderate,
permanent, and localized.
5.2.2 Water Resources
5.2.2.1 StudyArea Description
The study area for water resources encompasses the area within 300 feet of the edges of the long-term
proposed Project footprint, which is defined as the physical footprint of the truck access routes that
330
would result in permanent impacts on water resources. This distance was selected to match the typical
largest applicable potential buffer width for wetlands within the City of Tukwila, the City of Seattle, and
unincorporated King County.
5.2.2.2 Past, Present, and Reasonably Foreseeable Future Actions
The study area for water resources is highly developed from past and present actions. The RFFAs within
this study area have been determined to not have any significant environmental impacts to water
resources.
5.2.2.3 Cumulative Effects
5.2..2..3.1. No Action Alternative
Under the No Action Alternative, the proposed Project would not be developed and the associated
impacts to water resources would not occur. Because there would be no construction or new
disturbance of wetlands, groundwater, or surface water, cumulative impacts to water resources under
the No Action Alternative would be less than those under the other alternatives. Cumulative impacts to
this study area from past, present, and RFFAs, including the 42nd Avenue South bridge replacement
(TUK-62) are anticipated to be minor, temporary, and localized.
5.2..2..3.2. Alternative 2.
Under Alternative 2, there would be significant impacts to wetlands, moderate impacts to water quality,
and minor impacts to groundwater and floodplains. Therefore, cumulative impacts to the water
resources study area from the past, present, and RFFAs, combined with the actions proposed for
Alternative 2, would be significant, permanent, and localized.
5.2..2..3.3 Alternative 3B
Under Alternative 3B, there would be significant impacts to streams, moderate impacts to water quality,
and minor impacts to groundwater and floodplains. Therefore, cumulative impacts to the water
resources study area from the past, present, and RFFAs, combined with the actions proposed for
Alternative 3B, would be moderate to significant, permanent, and localized.
5.2..2..3.4 Alternative 4
Under Alternative 4, there would be moderate impacts to wetlands and water quality, and minor
impacts to floodplains and groundwater. Therefore, cumulative impacts to the water resources study
area from the past, present, and RFFAs, combined with the actions proposed for Alternative 4, would be
moderate, permanent, and localized.
5.2.3 Plants and Animals
5.2.3.1 Study Area Description
Plants and animals present in the Project vicinity were divided into three study areas: wetlands, aquatic
species and habitat, and terrestrial species and habitat. Each study area includes the footprint for the
respective alternative (No Action Alternative, Alternative 2, Alternative 3B, or Alternative 4) and for the
specified adjacent areas that could be affected by Project activities.
5.2.3.2 Past, Present, and Reasonably Foreseeable Future Actions
The study area for the plant and animal resources is highly developed from past and present actions; the
land uses in this area are primarily zoned as residential, commercial, and industrial interspersed with
331
urban parks and green spaces. The RFFAs within this study area have been determined to not have any
significant environmental impacts to plant and animal resources.
5.2.3.3 Cumulative Effects
5.2..3.3.1. No Action Alternative
Under the No Action Alternative, the proposed Project would not be developed and the associated
impacts to plant and animal resources would not occur. Because there would be no construction or new
disturbance of land, cumulative impacts to plant and animal resources under the No Action Alternative
would be less than those under the other alternatives. Cumulative impacts to this study area from past,
present, and RFFAs, including the 42nd Avenue South bridge replacement (TUK-62) are anticipated to be
minor, temporary, and localized.
5.2..3.3.2. Alternative 2.
Under Alternative 2, there would be minor to moderate impacts to plant and animal resources from
construction activities. Operational activities for Alternative 2 would have no to minor impacts to plant
and animal resources. Therefore, cumulative impacts to the geology and soils study area from the past,
present, and RFFAs, combined with the actions proposed for Alternative 2, would be moderate,
permanent, and localized
5.2..3.3.3 Alternative 3B
Under Alternative 3B, there would be minor to moderate impacts to plant and animal resources during
the construction phase, and there would be moderate to mitigated significant impacts to wetlands and
aquatic habitats for plant and animal resources. Therefore, cumulative impacts to the plant and animal
study area from the past, present, and RFFAs, combined with the actions proposed for Alternative 3B,
would be moderate to mitigated significant, permanent, and localized.
5.2..3.3.4 Alternative 4
Under Alternative 4, there would be minor moderate impacts to plant and animal resources during the
construction phase, and there would be moderate to mitigated significant impacts to wetlands and
aquatic habitats for plant and animal resources. Therefore, cumulative impacts to the plants and animals
study area from the past, present, and RFFAs, combined with the actions proposed for Alternative 4,
would be moderate to mitigated significant, permanent, and localized.
5.2.4 Land Use, Shoreline Use, and Recreation
5.2.4.1 Study Area Description
The study area for the Land Use, Shoreline Use, and Recreation resources is defined as the footprint, the
truck traffic routes (excluding highways), and a 200-foot buffer for each of the proposed Alternatives to
evaluate impacts to adjacent properties.
5.2.4.2 Past, Present, and Reasonably Foreseeable Future Actions
The study area for land use, shoreline use, and recreation is highly developed from past and present
actions and is primarily comprised commercial, industrial, and residential areas interspersed with urban
parks and green spaces. The RFFAs within this study area have been determined to not have any
significant environmental impacts to land use, shoreline use, and recreation.
332
5.2.4.3 Cumulative Effects
5.2..4.3.1. No Action Alternative
Under the No Action Alternative, the proposed Project would not be developed and the associated
impacts to land use, shoreline use, and recreation resources would be based upon the current operating
conditions of the current truck route. The No Action Alternative routes truck traffic through residential
areas, and is adjacent to recreational areas, resulting in significant impacts that are the impetus of this
EIS. Cumulative impacts to this study area from past, present, and RFFAs, are anticipated to be
significant, long-term, and localized.
5.2.4.3.2. Alternative 2.
Under Alternative 2, there would be significant impacts on recreation resources during the construction
phase, but no impacts to shoreline use or general land use. After construction and applied mitigation,
however, operational impacts to study area would be reduced to minor or no impact. Therefore,
cumulative impacts to the land use, shoreline use, and recreation study area from the past, present, and
RFFAs, combined with the actions proposed for Alternative 2, would be minor to moderate, permanent,
and localized
5.2..4.3.3 Alternative 3B
Under Alternative 3B, there would be moderate impacts on land use, shoreline use, and recreation
during both the construction and operational phases. The completion of the new bridge and the
connectivity it could bring to recreational areas would result in a minor beneficial impact. Therefore,
cumulative impacts to the study area from the past, present, and RFFAs, combined with the actions
proposed for Alternative 3B, would be minor to moderate, permanent, and localized.
5.2..4.3.4 Alternative 4
Under Alternative 4, there would be significant impacts to land use as residentially zoned parcels would
be razed and would need to be rezoned as industrial. Impacts to shoreline use and recreation minor to
moderate and temporary under Alternative 4. Due to the magnitude of the proposed alternative,
cumulative impacts to the land use study area from the past, present, and RFFAs, combined with the
actions proposed for Alternative 4, would be significant, permanent, and localized.
5.2.5 Air Quality and Greenhouse Gas
5.2.5.1 Study Area Description
The study area for evaluating impacts on air quality is within and near the Project site that could be
affected by construction and operation activities on the Project site. The Project site is in the Allentown
district of the City of Tukwila, Washington within King County. For the evaluation of climate and
greenhouse gases, the study area is discussed in terms of regional air quality, as changes in climate are
realized more broadly. Immediately adjacent properties to the BNSF facility are a sliver of undeveloped
land and Interstate 1-5 to the east; rail lines, overpass roads, and undeveloped land to the north; a
shooting range, residential and commercial property to the west; and rail lines, overpass roads and the
Duwamish River to the south.
5.2.5.E Past, Present, and Reasonably Foreseeable Future Actions
The study area for air quality and greenhouse gases is highly developed from past and present actions.
There is considerable existing roadway traffic in the study area. The RFFAs within this study area have
been determined to not have any significant environmental impacts to air quality and greenhouse gases.
333
5.2.5.3 Cumulative Effects
5.2..5.3.1. No Action Alternative
Under the No Action Alternative, the proposed current BNSF truck route would continue operating
under current conditions. Because there would be no construction or new disturbance of land which
could result in minor, temporary air quality impacts, No Action Alternative would have fewer impacts to
air quality than the other alternatives. However, construction activities unrelated to this alternative
would still occur as planned and permitted within the study area. Therefore, cumulative impacts to the
air quality and greenhouse gas study area from past, present, and RFFAs are anticipated to be minor,
temporary, and localized.
5.2.5.3.2 Alternative 2., Alternative 3B, and Alternative 4
Under Alternatives 2, 3B, and 4, there would be minor, temporary impacts to air quality during
construction. Once an alternative is selected as the preferred alternative and the project design is
formalized, additional studies would be required to determine quantitatively, not just qualitatively, the
magnitude of impacts the preferred alternative would have on air quality resources. Therefore,
cumulative impacts to the air quality study area from the past, present, and RFFAs, cannot be fully
assessed at this conceptual level of project design. Qualitative analysis indicates that there is a potential
for adverse effects to air quality resources, however, until a full traffic study is completed the
cumulative effects cannot be appropriately quantified.
5.2.6 Transportation
5.2.66.1 Study Area Description
The study area encompasses routes with key roadways and intersections that connects the local
freeway network to the BNSF facility. The proposed alternatives in this study (No Action Alternative,
Alternative 2, Alternative 3B and Alternative 4) are reconfigurations of the existing BNSF yard, which
would also modify the existing truck routes currently used by trucks to travel to the facility. For
construction impacts, the study area consists of the roads and intersections that construction vehicles
would use to access the proposed Project site. For operational impacts, the study area consists of roads
and intersections used by trucks moving to and from the BNSF facility to access the proposed alternative
footprints.
5.2.66.2 Past, Present, and Reasonably Foreseeable Future Actions
The study area for transportation resources is highly developed from past and present actions. The
RFFAs within this study area have been determined to not have any significant environmental impacts to
transportation resources.
5.2.66.3 Cumulative Effects
5.2..6.3.1. No Action Alternative
Under the No Action Alternative, the proposed the BNSF truck route would continue to operate under
current conditions. The community population and traffic volume would continue to grow at its current
rate, and level of service, vehicle miles traveled, and pavement condition would be impacted
proportionately to that usage. Cumulative impacts to this study area from past, present, and RFFAs are
anticipated to be minor, long-term, and localized.
334
5.2..6.3.2. Alternative 2.
Under Alternative 2, there would be minor impacts to level of service, vehicle miles traveled, and
pavement condition during the operational phase. As the community continues to grow, cumulative
impacts to the transportation study area from the past, present, and RFFAs, combined with the actions
proposed for Alternative 2, would be minor, long-term, and localized.
5.2..6.3.3 Alternative 3B
Under Alternative 3B, there would be minor impacts to level of service, vehicle miles traveled, and
pavement condition during the operational phase. As the community continues to grow, cumulative
impacts to the transportation study area from the past, present, and RFFAs, combined with the actions
proposed for Alternative 3B, would be minor, long-term, and localized.
5.2..6.3.4 Alternative 4
Under Alternative 4, there would be significant impacts to level of service, moderate impacts to vehicle
miles traveled, and minor impacts to pavement condition during the operational phase. As the
community continues to grow, cumulative impacts to the transportation study area from the past,
present, and RFFAs, combined with the actions proposed for Alternative 4, would be moderate to
significant, long-term, and localized.
5.2.7 Health and Safety
5.2.7.1 Study Area Description
The study area for the environmental health and safety analysis is a 0.5-mile radius from the footprint of
each alternative. A 0.5-mile search radius was used to match the ASTM-defined search radius for state -
listed contaminated sites.
5.2.7.2 Past, Present, and Reasonably Foreseeable Future Actions
The study area for Health and Safety is highly developed from past and present actions. The RFFAs
within this study area have been determined to not have any significant environmental impacts to
health and safety.
5.2.7.3 Cumulative Effects
5.2..7.3.1 No Action Alternative
Under the No Action Alternative, the proposed the BNSF truck route would continue to operate under
current conditions. The No Action Alternative routes truck traffic through residential area, and is
adjacent to recreational areas resulting in moderate impacts. Cumulative impacts to this study area from
past, present, and RFFAs, are anticipated to be moderate, long-term, and localized.
5.2..7.3.2. Alternative 2., Alternative 3B, and Alternative 4
Under Alternatives 2, 3B, and 4, there would be moderate impacts to health and safety during both the
construction phase and the operational phase of the selected alternative. Cumulative impacts to the
health and safety study area from the past, present, and RFFAs, combined with the actions proposed for
the selected alternative, would be moderate, long-term, and localized.
335
5.2.8 Public Services and Utilities
5.2.8.1 StudyArea Description
The study area for the public services and utilities analysis is the service areas of the public service
agencies and utility providers in relation to proposed Project build alternatives and the No Action
Alternative.
5.2.8.2 Past, Present, and Reasonably Foreseeable Future Actions
The study area for public services and utilities is highly developed from past and present actions. The
RFFAs within this study area have been determined to not have any significant environmental impacts to
these resources.
5.2.8..E Cumulative Effects
5.2..8.3.1. No Action Alternative
Under the No Action Alternative, the proposed the BNSF truck route would continue to operate under
current conditions. There would be no construction or change in route, conditions, or current level of
impact on public services and utilities. No impact is anticipated for cumulative effects to this study area
from past, present, and RFFAs.
5.2..8.3.2. Alternative 2., Alternative 3B, and Alternative 4
Under Alternatives 2, 3B, and 4, there would be moderate impacts to stormwater during both the
construction phase and the operational phase of the selected alternative. Impacts to public services and
utilities such as police and sheriff, fire, domestic water, sewer, electricity, and solid waste are
anticipated to be minor for the construction phase and moderate during the operational phase of the
selected alternative. Cumulative impacts to the public services and utilities study area from the past,
present, and RFFAs, combined with the actions proposed for the selected alternative, would be
moderate, long-term, and localized.
5.2.9 Cultural Resources
5.2.9.1 StudyArea Description
The study area for cultural resources consists of the footprint for Alternatives 2, 3B, and 4, and
surrounding areas that would be affected by construction of the proposed action.
5.2.9.2 Past, Present, and Reasonably Foreseeable Future Actions
The study area for cultural resources is highly developed from past and present actions. The RFFAs
within this study area have been determined to not have any significant environmental impacts to these
resources.
5.2.9..E Cumulative Effects
5.2..9.3.1. No Action Alternative
Under the No Action Alternative, the BNSF truck rout would continue to operate under current
conditions. Because there would be no construction or new disturbance of land, cumulative impacts to
cultural resources under the No Action Alternative would be less than those under the other
alternatives. There are no anticipated cumulative impacts to this study area from past, present, and
RFFAs.
336
5.2..9.3.2. Alternative 2.
Alternative Study Area 2 has a very high likelihood to impact multiple historic built -environment
resources that are either eligible for the NRHP individually or contribute to the potential SPAA Historic
District. Cumulative impacts to the cultural resources study area from the past, present, and RFFAs,
combined with the actions proposed for Alternative 2, would be significant, permanent, and localized.
5.2..9.3.3 Alternative 3B
Under Alternative 3B there is a potential for adverse impacts to S&WW/PSS/SLS&E/NP (Property ID
708606). These impacts would be temporary and not have the potential to impact the character -
defining features of the railway segment. Cumulative impacts to the cultural resources study area from
the past, present, and RFFAs, combined with the actions proposed for Alternative 3B, would be minor,
temporary, and localized.
5.2..9.3.4 Alternative 4
Under Alternative 4 there is a potential for adverse impacts to S&WW/PSS/SLS&E/NP (Property ID
708606). These impacts would be temporary and not have the potential to impact the character -
defining features of the railway segment. Cumulative impacts to the cultural resources study area from
the past, present, and RFFAs, combined with the actions proposed for Alternative 4, would be minor,
temporary, and localized.
5.2.10 Noise
5.2.10.1 Study Area Description
The noise study area for construction and operational noise is an area extending 500 feet from the No -
Action truck route and the route alternatives. This corresponds to the typical study area extents of a
Federal Highway Administration (FHWA) traffic noise study.
5.2.10.2 Past, Present, and Reasonably Foreseeable Future Actions
The study area for Noise is highly developed from past and present actions. The RFFAs within this study
area have been determined to not have any significant environmental impacts to this resource.
5.2.10.3 Cumulative Effects
5.2.10.3.1 No Action Alternative
Under the No Action Alternative, the proposed Project would not be developed, and the associated
impacts of noise would be based upon the current operating conditions of the current truck route. The
No Action Alternative routes truck traffic through residential areas, and is adjacent to recreational areas
resulting in significant impacts that are the impetus of this EIS. Cumulative impacts to this study area
from past, present, and RFFAs, are anticipated to be significant, long-term, and localized.
5.2.1.0.3.2. Alternative 2.
Under Alternative 2, there would be mitigated moderate impacts from noise. The area where
Alternative 2 would be is currently police training gun range which generates noise as well. At this time,
it is not clear how the noise generated from the BNSF facility would differ from the current noise
impacts, but cumulative impacts from the past, present, and RFFAs, combined with the actions
proposed for Alternative 2, are anticipated to be mitigated moderate, long-term, and localized.
337
5.2.1.0.3.3 Alternative 3B
Under Alternative 3B, there would be moderate impacts from noise on neighboring residential and
commercial areas. Cumulative impacts from the past, present, and RFFAs, combined with the actions
proposed for Alternative 3B, are anticipated to be moderate, long-term, and localized.
5.2.1.0.3.4 Alternative 4
Under Alternative 4, there would be significant impacts from noise on neighboring residential areas. The
entrance area to the BNSF facility would be moved farther to the south, closer to residential structures.
Cumulative impacts from the past, present, and RFFAs, combined with the actions proposed for
Alternative 3B, are anticipated to be significant, long-term, and localized.
5.2.11 Environmental Justice
5.2.11.1 Study Area Description
To determine the presence of EJ populations in the affected environment, a 0.5-mile radius was applied
to the No Action Alternative, Alternative 2, Alternative 3B, and Alternative 4 to form study areas for
each of the alternative. The 0.5 mi radius was determined by recommended guidance from WSDOT
(2014).
Census tracts were used to analyze the presence of EJ populations in the alternatives' study areas. Tract
data was selected because it provides a stable set of geographic units for the presentation of statistical
data, and they contain a larger population size compared to other statistical boundaries used by the U.S.
Census Bureau (USCB 2022).
The U.S. Census Bureau was used to pull census tract level percentages of minority and low-income
populations. Percentages for City of Tukwila and King County were also listed for comparison. The
American Community Survey (ACS) five-year, 2018-2022 dataset was used for this analysis. Minority
data was pulled from the Race and Ethnicity ACS Demographic and Housing Estimates table (Table ID:
DP05), and low-income data was pulled from the Poverty Status in the Past 12 Months table (Table ID:
S1701). For the purposes of this analysis, an alternative or census tract is classified as having EJ
populations if their minority and low-income population percentages are equal to or higher than the
City of Tukwila and King County.
5.2.11.2 Past, Present, and Reasonably Foreseeable Future Actions
The study area for Environmental Justice is relatively uniform in terms of minority populations and
resident income level between all four alternatives. The RFFAs within this study area have been
determined to not have any significant environmental impacts to minority or low-income communities
in the Environmental Justice study area.
5.2.11.3 Cumulative Effects
5.2 11 3.1 No Action Alternative, Alternative 2., Alternative 3, and Alternative 4
There would be no disproportionately high and adverse impacts on environmental justice populations
during construction and operations of any selected alternative for this proposed Project. Mitigation and
standard BMPs would be implemented and would reduce the likelihood and magnitude of identified
adverse impacts. These impacts, however, would not be absorbed disproportionately by minority or
low-income populations, but rather by all populations within the study. There are no additional
cumulative impacts from the past, present, or RFFAs that would disproportionately affect minority or
low-income populations.
338
5.2.12 Visual Resources and Aesthetics
5.2.12.1 Study Area Description
The study area for visual resources and aesthetics, or area of visual effect (AVE), is generally defined as
the limit of disturbance of proposed construction and the truck route for each alternative plus a half -
mile buffer. The AVE was determined by physical constraints of the environment, the level of existing
urban and industrial or commercial development, and the physiological limits of human sight.
5.2.12.2 Past, Present, and Reasonably Foreseeable Future Actions
The study area for visual resources and aesthetics is highly developed from past and present actions.
The study area is considered to have an urban landscape. The RFFAs within this study area have been
determined to not have any significant environmental impacts to visual resources and aesthetics.
5.2.12.3 Cumulative Effects
5.2.. t2..3.1. No Action Alternative
Under the No Action Alternative, the proposed Project would not be developed and the associated
impacts to visual resources would continue under current conditions. Because the AVE of this
alternative is within residential areas, the operation of this alternative has a moderate impact on visual
resources. Cumulative impacts to this study area from past, present, and RFFAs are anticipated to be
moderate, long-term, and localized.
5.2.. t2..3.2. Alternative 2.
Under Alternative 2, there would be moderate impacts to visual resources during the construction
phase, and significant impacts during the operation phase from alterations to the topography and
landcover. Cumulative impacts to the visual resources AVE from the past, present, and RFFAs, combined
with the actions proposed for Alternative 2, would be significant, permanent, and localized.
5.2.1.2..3.3 Alternative 3B
Under Alternative 3B, there would be minor impacts to visual resources during the construction phase,
and moderate impacts during the operation phase from alterations landcover and the addition of the
proposed bridge as a new infrastructure feature. Cumulative impacts to the visual resources AVE from
the past, present, and RFFAs, combined with the actions proposed for Alternative 3B, would be
moderate, permanent, and localized.
5.2.1.2..3.4 Alternative 4
Under Alternative 4, there would be moderate impacts to visual resources during the construction
phase, and significant impacts during the operation phase from alterations to land use, landcover,
topography, and the addition of a new infrastructure such as industrial buildings and noise walls.
Cumulative impacts to the visual resources AVE from the past, present, and RFFAs, combined with the
actions proposed for Alternative 4, would be significant, permanent, and localized.
339
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7 A
opendices
353
Appendix A: Public Comments and Response to Public Comments
Appendix IR:: Plan Sheets For the Alternatives
Appendix C: Wetlla nd and Stream Techln call Report
c
Appendix D:: Allentown EDS intersection Study
.Appendix IF: Precontact, Ethnographic, and Historic Context for Cultural Resources within
the Study Area
E