HomeMy WebLinkAboutPermit L92-0009 - KING COUNTY - METRO PUMP STATION ENVIRONMENTAL IMPACT STATEMENT (EIS)l92-0009 13980 interurban avenue south
king county metro pump station alki transfer cso metro
ENVIRONMENTAL IMPACT STATEMENT (EIS)
Final SEPA
Supplemental Environmental Impact Statement.
and
NEPA Environmental Assessmen
RECEIVE
SEP 0.9 1992
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DEVELOPMENT
Clean Water - A Sound Investment
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RECEIVED
SEP 0 91992
COMMUNITY
DEVELOPMENT
Final SEPA
Supplemental
Environmental Impact Statement
and
NEPA Environmental
Assessment
on the
Alki Transfer /CSO
Facilities Project
Municipality of Metropolitan Seattle
April 1992
Prepared in compliance with the State Environmental Policy Act (SEPA) (RCW 43.21 C) the SEPA Rules
(WAC 197 -11) and Metro Resolutions 4480 and 4925 implementing SEPA in Metro procedures
This document is also intended to satisfy Environmental Protection Agency requirements under
the National Environmental Policy Act (NEPA) (42 U.S.C. 4321 gt. deg. and applicable agency regulations
RECEIVED
SEP 0 9 1992
COMMUNITY
DEVELOPMENT
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TO: Recipients of Final Supplemental EIS
Alki Transfer /CSO Facilities Project
This final environmental impact statement compares alternative methods for transfering
Alki service area wastewater flows to another treatment plant operated by Metro for
secondary treatment. The EIS also evaluates the conversion of the existing Alki primary
treatment plant to intermittent operation to treat wastewater flows during extremely wet
weather. This final EIS supplements the final and final supplemental environmental impact
statements on the Plan For Secondary Treatment Facilities and Combined Sewer Overflow
Control (Metro, 1985, 1986).
Four alternatives are evaluated in this EIS. Each alternative would transfer flows from the
Alki service area to Metro's West Point Treatment Plant for secondary treatment. The
West Point plant does not have the capacity to treat the Alki flows, particularly during
peak storm events. As a result, all four alternatives also include a transfer of equivalent
flows from Metro's south Seattle service area to Metro's treatment plant at Renton. Three
different systems are evaluated for the southern transfer to the plant in Renton. Capacity
is available at the plant at Renton to treat the additional flows.
Metro's preferred alternative is Alternative 2 (Small Diameter Tunnel, through West
Seattle), the Alki stormweather plant, combined with the Allentown /Interurban Avenue
southern transfer to Metro's treatment plant at Renton. The southern transfer incorporates
Metro's plans for improving the trunk sewer system serving the Val Vue Sewer District and
City of Tukwila (Interurban Sewer System Improvement Project). This alternative includes
the conversion of the existing Alki plant to intermittent operation.
Alternative 1 (Around Duwamish Head) includes converting the existing Alki Treatment
Plant to intermittent operation, and transfering Alki service area base flows (up to 19
million gallons per day (mgd)) to Metro's West Point collection system. A new pumping
station would be constructed at the Alki plant site and a pipeline would be constructed
from the pumping station along Alki Avenue Southwest and Harbor Avenue Southwest,
into the Duwamish industrial area then west under the Duwamish River connecting to
Metro's Elliott Bay Interceptor (EBI).
Alternative 2 and 3 are both tunneling alternatives that include a transfer of flows from
Metro's existing 63rd Avenue pumping station to a tunnel that would be constructed along
an alignment generally under Southwest Hanford Street. A pumping station would be
constructed at the east tunnel portal, located near Harbor Avenue Southwest, to transport
flows into the Duwamish industrial area and to the EBI, along the same alignment as
Alternative 1. No new facilities would be constructed at the Alki plant site.
Alternative 4, Underwater Alki to West Point, includes the intermittent plant at Alki, a
pumping station at the Alki plant site, and a pipeline that proceeds north from the pumping
station offshore and under Elliott Bay directly to the West Point plant at the south beach of
West Point.
The following southern transfer alternatives are evaluated in the EIS and would combine
with a West Point transfer alternative to complete the Alki transfer system.
The Norfolk Street /Railroad southern transfer alternative starts from an area near the
Interstate 5 and South Norfolk Street, and would consist of a pipeline system that
proceeds south along Burlington Northern /Union Pacific railroad right -of -way to the
Metro treatment plant at Renton.
1 The East Marginal Way /Interurban Avenue southern transfer alternative starts from the
same location at South Norfolk Street, and includes a pipeline that proceeds south
along East Marginal Way through Tukwila across the Duwamish River to Interurban
Avenue South, and then south along Interurban Avenue South and across the
Duwamish River, at Fort Dent Park, to the Metro treatment plant in Renton.
1 The Allentown /Interurban Avenue alternative is Metro's preferred alternative for
accomplishing the southern transfer. The system begins from Metro's Henderson Trunk
in South Seattle. The pipeline would proceed south along Airport Way South, railroad
right -of -way, and through Allentown in street right -of -way and under the Duwamish
River to Interurban Avenue South.
Once on Interurban Avenue South, the system is designed to carry flows from both the
Alki southern transfer and Metro's Interurban Sewer System Improvement Project. The
pipeline would then follow the same alignment to the Metro treatment plant at Renton
described for the East Marginal Way/ Interurban Alternative.
Environmental issues: The Alki project would cause short -term construction and long -term
operation impacts. Construction would affect local residences, the Bar S Playfield, and
local streets, producing increased noise levels, increased truck traffic and dust. By
reducing the plant to intermittent operation, discharges of treated effluent will be
significantly reduced producing an overall improvement in the quality of the receiving
waters. With secondary treatment of base flows at the West Point plant a greater
quantity of pollutants will be removed from wastewater prior to discharge to Puget Sound.
Alternative 1 would produce temporary construction impacts (traffic congestion and
access restrictions, noise and dust) to recreational areas along Alki Avenue Southwest and
Harbor Avenue Southwest.
The tunneling alternatives (2 and 3) would concentrate construction impacts at the tunnel
portals. The tunnel would be constructed from east to west to minimize impact to West
Seattle neighborhoods. The majority of the truck traffic would be associated with
removing tunnel spoils at the east tunnel portal.
Alternative 4 would produce some loss and temporary displacement of benthic organisms
in intertidal areas. Also some quantity of eelgrass at Alki Beach and the south beach at
West Point would be lost in the construction corridor.
Construction of the transfer to the treatment plant at Renton could impact wetlands
located along the railroad right -of -way, and construction in street right -of -way through
Tukwila or Allentown would produce temporary increases in truck traffic, noise levels, and
dust levels. Recreational resources in Fort Dent Park would also be temporarily impacted
by construction activities.
Metro Council decision: In 1986, the Metro Council adopted Resolution 4780, which
amended the comprehensive plan and included the decision to transfer Alki service area
base flows and convert the existing Alki treatment plant to stormweather operation.
This supplemental EIS includes the environmental review for the amendment of Metro's
comprehensive plan addressing the Alki plan, as required by Resolution 4780. Resolution
4780 requires a comprehensive plan amendment when the decision is made on the Alki
transfer.
Project funding: The capital cost of the alternatives range from $80 million to $177 million
(1991 dollars). Metro is proposing to fund the project construction costs through a
combination of local funding and a federal grant. The amount of grant funding would be
about $35 -40 million, with the remaining project costs paid by all Metro ratepayers.
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FACT SHEET
Name of Proposal Alki Transfer /CSO Facilities Project
Description of Proposal Metro is proposing to provide secondary treatment to wastewater
collected from the Alki service area.
Location of Proposal
ALKIFACT
In 1986, the Metro Council adopted a comprehensive plan for
upgrading the Metro system so that secondary treatment would be
provided to all sewage in the region. At that time, Metro evaluated
two alternatives for the Alki service area, which covers much of West
Seattle: (1) upgrade the plant to include secondary treatment, or
(2) transfer the sewage to another plant for secondary treatment and
retain the existing plant to treat high flows that occur during storms.
The council decided to pursue the second option, with transfer of Alki
flows to another Metro plant for secondary treatment. Conversion of
the Alki plant to a storm - weather treatment facility would not involve
expanding the existing Alki facilities.
Metro has determined that the most cost - effective way to transfer
Alki flows to another treatment plant is to build a transfer line from
Alki to the West Point Treatment Plant or to the major collection
system leading to it.
Capacity is not available at the West Point plant to treat the Alki
flows, particularly during peak storm events. As a result, it will be
necessary to transfer an equivalent amount of flow from the West
Point service area to Metro's regional treatment plant at Renton.
Capacity is available at the Renton plant to treat the additional flows.
This part of the proposal is known as the Southern Transfer.
This final EIS evaluates three alternatives that transfer up to 19 million
gallons per day to the West Point Treatment Plant, and one alternative
that transfers all Alki service area flows to the West Point Treatment
Plant. The alternative that provides for transfer of all flows from the
Alki service area would not include construction of the stormweather
plant at Alki. The Southern Transfer would operate at all times
conveying up to 19 mgd peak flows to Metro's regional treatment
plant at Renton. The EIS evaluates the impact of transferring Alki
flows, the impacts of construction and operation of conveyance
systems, and the impacts of construction and operation of the
stormweather plant at Alki. It also includes the environmental review
for the amendment of Metro's Comprehensive Water Pollution
Abatement Plan.
Construction would begin in 1993 and is anticipated to be completed
in 1996.
Elements of the project would be located within the cities of Seattle,
Tukwila, King County and Renton. The proposed project involves
facilities at or near the Alki Treatment Plant (3350 Beach Drive
Southwest) and a conveyance pipeline extending from the Alki
Treatment Plant area to either the West Point Plant (4215 36th
Avenue West) or to Metro's Elliott Bay interceptor in the Duwamish
Valley. The southern segment of the project would involve a
conveyance pipeline extending southward from a proposed pumping
station in the vicinity of Interstate 5 and South Norfolk Street to
Metro's regional treatment plant at Renton.
Proponent /Lead Agency Municipality of Metropolitan Seattle (Metro). Metro is cooperating
with federal agencies, including the U.S. Environmental Protection
Agency (EPA) in preparing this document.
Responsible Official Gregory M. Bush, Manager of Environmental Compliance
Municipality of Metropolitan Seattle
821 Second Ave., M.S. 120
Seattle, WA 98104 - 1598
Contact Person Ellis K. McCoy
(206) 684 -6779
Preparers and
Contributors Metro staff
CWC - HDR, Inc. (Engineering)
Adolfson Associates, Inc. (Environmental Analysis)
CTS Engineers, Inc. (Environmental, Traffic Analysis)
CH2M Hill, Inc. (Environmental Cumulative Analysis)
Converse Consultants N.W. (Geotechnical Analysis)
Beak Consultants, Inc. (Marine Biology)
Permits Depending upon the alternative selected, permits may include:
Washington Department of Ecology
NPDES permit
Water quality certifications
Certification of consistency with coastal zone management
program
Washington Department of Fisheries
Hydraulic project approvals
Washington Department of Natural Resources
Tidelands lease
Dredge disposal permit
Duwamish River easement
Washington Department of Transportation
Highway Crossing permit
ALKIFACT ii
Permits (cont.)
Date Draft EIS Issued
Date of Public Hearing(s)
ALKIFACT iii
U.S. Army Corps of Engineers
Permit for work in navigable waters (Section 10)
Permit for filling waters of U.S. or adjacent wetlands (Section
404)
U.S. Coast Guard
Authorization for Disruption of Maritime Traffic
King County
Shoreline Substantial Development permit
Grading permits
City of Seattle
Shoreline substantial development permits
Council Conditional -Use Approval
Street -Use permits
Grading permit
Utility permits
Building permit
City of Tukwila
Shoreline Substantial Development permit
Excavation permit
Street -Use permit
City of Renton
Shoreline Substantial Development permit
Street -Use permit
Burlington Northern Railroad and Union Pacific Railroad
Pipeline permits
Pipeline crossing permits
Road crossing permits
Puget Sound Air Pollution Control Agency
Notice of construction and application for approval
December 23, 1991
January 21, 1992
7:00 p.m.
Magnolia Community Center
2550 34th Avenue West
Seattle
January 23, 1992
7:00 p.m.
Hiawatha Recreation Center
2700 California Avenue SW
Seattle
January 22, 1992
7:00 p.m.
Foster Golf Links
13500 Interurban Avenue South
Tukwila
End of Comment Period
Address Written
Comments to
Public Meetings
Date Final EIS Issued
Planned Action by
Metro Council
Subsequent Environ-
mental Review
January 29, 1992
Gregory M. Bush, Manager, Environmental Compliance Division
METRO
821 Second Ave., M.S. 120
Seattle, WA 98104 -1598
January 18, 1992
10 a.m.- 2 p.m. (Open House)
Alki Treatment Plant
3380 Beach Drive SW
Seattle
January 22, 1992
5:00 p.m.
Foster Golf Links
13500 Interurban Avenue S.
Tukwila
April 27, 1992
ALKIFACT iv
January 21, 1992
5 p.m.
Magnolia Community Center
2550 34th Avenue West
Seattle
January 23, 1992
5:00 p.m.
Hiawatha Recreation Center
2700 California Avenue SW
Seattle
Following issuance of this final EIS, the Metro Council will select an
alternative and amend the Comprehensive Water Pollution Abatement
Plan to implement that alternative. Based on the selected alternative,
the Metro Council will award contracts for construction. The Council
anticipates awarding contracts for the project in 1994.
This supplemental EIS is part of a "phased" environmental review
process. This final supplemental EIS satisfies Metro's commitment to
provide site- specific, project -level environmental information on the
Alki Transfer /CSO Facilities Project. The EIS has been revised to
reflect issues raised during the public comment period. Supplements
or addenda to this final EIS may be issued if warranted by project
changes or new information.
This final supplemental EIS has been prepared in accordance with
WAC 197 -11 -460 and Metro's SEPA rules. It will be circulated to all
recipients of the December 1991 Draft Supplemental EIS on the Alki
Transfer /CSO Facilities Project. No comment period is required for the
final EIS but readers should call Metro if they have questions. Metro
will not act on this proposal prior to seven (7) days after issuance of
this final EIS.
Pursuant to Metro Resolution 4480 implementing SEPA in Metro
procedures, you may appeal this environmental . document to Richard
K. Sandaas, Executive Director, at Metro - 821 Second Avenue,
Seattle, Washington 98104. Appeals must be filed within fifteen (15)
days of issuance of this final EIS.
Metro will be seeking federal funding for this project from the
Environmental Protection Agency (EPA). Prior to providing funding,
EPA must satisfy the environmental review requirements of the
L
is
ti
i
Documents Incorporated
by Reference
Availability of Final EIS
ALKIFACT V
National Environmental Policy Act (NEPA) (42 U.S.C. 4321 et. sea.),
and EPA's implementing regulations (40 C.F.R. Part 6). This SEPA
document will also serve as EPA's final environmental assessment
under NEPA.
Current and previous EISs for Metro's Comprehensive Water Pollution
Abatement Plan and Amendments, as well as technical reports,
background data and supporting documents are available at the Metro
Library, Ninth Floor, 821 Second Ave., Seattle. Incorporated by
reference in this EIS are: final and final supplemental EIS, Plan for
Secondary Treatment Facilities and Combined Sewer Overflow Control
and associated technical appendices, (Metro 1985, 1986); final EIS,
Wastewater Management Plan for the Lake Washington /Green River
Basins (EPA, 1981); final supplemental EIS on the Puget Sound
Facilities Engineering Report (Metro, 1983); final supplemental EIS,
Renton Effluent Transfer System for the Wastewater Management
Plan, Lake Washington /Green River Basins (Metro, 1984); final EIS -
Municipality of Metropolitan Seattle Sludge Management Plan (EPA,
1983); final EIS - Duwamish 201 Facility Configuration and Metro
CSO Control Program (EPA, 1979); final supplemental EIS, West Point
Secondary Treatment Facilities (Metro 1988); final supplemental EIS;
Metro Treatment Plant at Renton Phase III Enlargement (Metro 1991);
environmental checklist for Interurban Sewer System Improvement
Project (Metro, 1991); and all documents incorporated by reference in
those EISs.
The Alki Transfer /CSO Facilities Project EIS is available at no cost to
interested citizens. Copies may be obtained from Metro's
Environmental Compliance Division, 12th Floor, Exchange Building,
821 Second Ave., Seattle, WA 98104 -1598. One copy will be
provided to each individual.
11141111 Ms imasi
TABLE OF CONTENTS
Cover Memo
Fact Sheet
Table of Contents vii
List of Tables viii
List of Figures ix
Chapter 1: Summary
Proposal and Objectives 1 -1
Purpose and Need 1 -2
Potential Benefits of Project 1 -2
Public and Agency Review 1 -2
Scope of this Supplemental EIS 1 -3
Changes Made After Draft EIS was Issued 1 -3
Stormweather Treatment Plant 1 -4
Alki to West Point Transfer 1 -4
Southern Transfer 1 -7
Impacts and Mitigation Measures 1 -8
Significant Adverse Impacts that Cannot be Mitigated 1 -8
Significant Areas of Controversy and Uncertainty and Issues to be Resolved 1 -8
Chapter '2: Background
Relationship to Metro System 2 -1
Secondary Treatment Planning Process 2 -1
Existing Alki System 2 -5
Other Elements of the Metro System 2 -8
Chapter 3: Alternatives
Introduction 3 -1
Stormweather Treatment Plant 3 -2
Alki to West Point Transfer 3 -3
Southern Transfer 3 -8
Project Schedule 3 -15
Other Alternatives Considered 3 -18
Benefits and Disadvantages of Delaying Action 3 -22
Chapter 4: Description of Affected Environment
Introduction 4 -1
Natural Environment
Earth Resources 4 -1
Air Resources /Odor 4 -7
Water Resources 4 -10
Biological Resources 4 -14
Energy 4 -26
Built Environment
Land and Shoreline Use 4 -27
Noise 4 -35
Environmental Health 4 -39
Recreation 4 -41
Aesthetics 4 -45
Transportation 4 -49
Historical /Archaeological Resources 4 -58
Utilities 4 -60
v i
TABLE OF CONTENTS (cont.)
Chapter 5: Environmental Impacts and Mitigation Measures
Introduction 5 -1
Natural Environment
Earth Resources 5 -3
Air Resources /Odor 5 -9
Water Resources 5 -13
Biological Resources 5 -19
Energy 5 -25
Built Environment
Land and Shoreline Use 5 -26
Noise 5 -30
Environmental Health 5 -38
Recreation 5 -39
Aesthetics 5 -44
Transportation 5 -46
Historical /Archaeological Resources 5 -58
Utilities 5 -59
Chapter 6: Public Participation
Chapter 7: Public Comments and Metro Responses
Distribution List
SEPA Elements of the Environment
Glossary
References
Appendices:
A - Plan Level Permit Conditions
B - Eliminated Transfer Alignments
C - Land Use consistency
vii
LIST OF TABLES
Table No. Title Page No.
1 -1 Elements of Alternatives 1 -5
1 -2 Comparison of Alternatives 1 -11
2 -1 Characteristics of CSO Discharges - Alki Service Area 2 -6
3 -1 Capital and Present Worth Cost Comparison (1991 dollars) 3 -17
4 -1 Summary of Odor Concentrations Associated with Sewage Treatment Process ....4 -9
4 -2 Washington State Water Quality Standards 4 -13
4 -3 Seattle - Maximum Permissible Sound Levels (dBA) 4 -37
4 -4 Summary of Surface Street Characteristics (Alki /Duwamish Area) 4 -51
4 -5 Summary of Surface Street Characteristics (Southern Transfer Corridor) 4 -56
5 -1 Projected Energy Usage for Alternatives 5 -26
5 -2 Typical Construction Equipment Noise (dBA) 5 -31
5 -3 Stormweather Plant Projected Construction Traffic Volumes and
Average Weekday Traffic on Principal Arterials 5 -47
5 -4 Estimated One -Way Trips (Truck Trips) 5 -48
5 -5 Levels -of- Service (Alternative 1) 5 -49
5 -6 Levels -of Service (Alternatives 2 & 3) 5 -52
5 -7 Levels -of- Service (Southern Transfer) 5 -53
viii
LIST OF FIGURES
Fig. No. Title Page No.
1 -1 Metro Preferred Alternative 1 -10
2 -1 Metro Service Area 2 -2
2 -2 Alki Service Area 2 -7
3 -1 Proposed Alki Stormweather Treatment Plant 3 -4
3 -2 West Point Transfer 3 -9
3 -3 Profile Tunnel Alignment 3 -10
3 -4 Profile Underwater, Alki to West Point 3 -11
3 -5 Southern Transfer 3 -12
3 -6 Proposed Norfolk Pumping Station Site 3 -13
3 -7 Project Schedule 3 -16
3 -8 Other Transfer Alignments Considered 3 -23
4 -1 Marine Resources of Alki Beach 4 -16
4 -2 Marine Resources Off West Point 4 -17
4 -3 Timing of Salmon Fresh -water Life Phases in Green - Duwamish Basin 4 -19
4 -4 Commercial Salmon Fishing Reporting Areas 4 -20
4 -5 Bald Eagle Nest, Perch, and Roost Locations in Discovery Park 4 -24
4 -6 Wetland Areas (visual surveys) 4 -25
4 -7 Land Use: Transfer to West Point 4 -28
4 -8 Shoreline Environments - Alki /Duwamish (Title 23) 4 -29
4 -9 Shoreline Environments - West Point (Title 23) 4 -30
4 -10 Land Use: Southern Transfer Corridor 4 -33
4 -11 Existing Noise Levels at Alki Treatment Plant 4 -40
4 -12 Parks and Recreation Locations: Alki Point and Vicinity 4 -46
4 -13 Parks and Recreation Locations: West Point /Magnolia 4 -47
4 -14 Parks and Recreation Locations: Southern Transfer Corridor 4 -50
4 -15 AWDT Volumes Existing Conditions Alki & Duwamish Areas 4 -52
4 -16 Key Intersections and Existing Levels -of- Service Alki & Duwamish Areas 4 -53
4 -17 Southern Transfer Corridor: Traffic Volume 4 -57
5 -1 Nearshore Environment of West Point South Beach 5 -2
5 -2 Fort Dent Park Crossing Alternatives 5 -43
5 -3 Construction Traffic Distribution (West Point Transfer) 5 -51
5 -4 Construction Traffic Distribution (Southern Transfer) 5 -54
ix
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Proposal and Objectives
CHAPTER 1
SUMMARY
Metro's proposed Alki Transfer /CSO Facilities Project would provide secondary treatment to
wastewater collected from the Alki service area. Metro currently provides primary treatment
at the existing Alki treatment plant. Secondary treatment removes substantially more
pollutants from wastewater than does primary treatment. This means that with secondary
treatment a smaller quantity of pollutants would be discharged to Puget Sound from
wastewater generated in the Alki service area. This would in turn improve water quality,
thus enhancing marine habitat and opportunities for fishing, swimming and boating.
In 1986, the Metro Council adopted a comprehensive plan for upgrading the Metro system
so that secondary treatment would be provided to all flows in the region. At that time, two
alternatives were evaluated for the Alki service area, which covers much of West Seattle: 1)
upgrading the Alki plant to include secondary treatment; or 2) transferring flows to another
plant for secondary treatment, and retaining the existing plant to treat high flows that occur
during storms. The Metro Council decided to pursue the second option, with transfer of
Alki flows to another Metro plant for secondary treatment. Conversion of the plant to a
stormweather treatment facility would not involve expansion of the existing Alki facilities.
Since 1986, Metro has evaluated possible methods to accomplish these objectives.
Analysis showed that the most cost - effective way to transfer Alki flows to another
treatment plant is to build a transfer line from Alki to Metro's West Point Treatment Plant or
to build a transfer line from Alki to Metro's major collection system leading to the West
Point plant. However, capacity is not available at the West Point plant to treat the Alki
flows, particularly during peak storm events. As a result, it will be necessary to transfer an
equivalent amount of flow from the West Point service area to Metro's regional treatment
plant at Renton. Capacity will be available at the plant in Renton to treat the additional
flows.
Each alternative considered in the EIS has three elements:
a transfer line between Alki and Metro's West Point plant or West Point collection
system trunk line (Alki to West Point Transfer);
a transfer line between Metro's Henderson trunk in south Seattle and Metro's regional
plant at Renton (Southern Transfer);
a stormweather plant at Alki (except Alternative 3- see below).
Under the proposed project, the transfer system from Alki will always pump a base non -
storm flow of about 8 million gallons per day (mgd) to West Point. As flows to the Alki
plant increase during storms, the increased flows would also be pumped, until the Alki
transfer system capacity of 19 mgd is reached. At that point, flows above 19 mgd would
be directed to the Alki stormweather plant.
The Southern Transfer system would operate at all times, conveying about 8 mgd during
average conditions, and up to 19 mgd peak flows, to the regional plant at Renton.
ALKI1
1 -1
This final supplemental EIS compares and evaluates the environmental impacts of
construction and operation of the alternative flow transfer systems. The EIS also evaluates
the environmental impacts of converting the existing Alki Treatment Plant to stormweather
operation.
Purpose and Need
Metro is under order by the Washington State Department of Ecology to provide secondary
treatment for its service area. Secondary treatment of Alki base flows would improve the
quality of that effluent which now receives only primary treatment before it is discharged
from an outfall off Alki point. This project would improve the overall quality of effluent
discharged to Puget Sound and reduce the frequency of effluent discharges at the Alki
outfall.
Potential Benefits of the Project
By transferring the base flow from Alki to West Point, additional capacity for storm flows
would be provided in the Alki system. As a result, discharges of CSO's at the 63rd Avenue
pumping station would be reduced during storms. All flows would be treated either at the
West Point plant or at the Alki stormweather plant. CSO's would be reduced in accordance
with Department Ecology guidelines.
As a result of building these transfer systems, Metro is avoiding the need to add secondary
treatment facilities at the Alki plant site. This means that the existing plant would continue
in use as a primary plant, operating intermittently during heavy storms, but additional
treatment facilities would not be needed. Because solids processing would no longer occur
at the Alki plant, sludge truck traffic to and from the plant would be eliminated. Operation
impacts of the stormweather plant would be reduced from current levels due to intermittent
rather than full -time operation of the plant.
By transferring most flows away from the Alki area, discharges of treated effluent off West
Seattle would be substantially decreased from existing conditions. Most flows from the Alki
area would receive secondary treatment, an improvement from the existing primary
treatment level, and would be discharged to Puget Sound at West Point. Improvement in
water quality in the vicinity of the Alki outfall is expected.
Public and Agency Review
The Alki Transfer /CSO Facilities predesign study began in the summer of 1988. Metro
issued a determination of significance for the proposed project, following the State
Environmental Policy Act (WAC 197 -11 -360), and as a result, Metro conducted an
environmental scoping process in July 1988 to determine the issues to be addressed in the
supplemental EIS for this project.
This draft supplemental EIS was circulated to all agencies with jurisdiction, affected tribes,
and interested groups and individual citizens for a 37 -day review period. A two week
extension was granted to seven respondents. Metro held three public hearings during the
comment period. Chapter 6, Public Participation, discusses the public involvement process
in more detail.
ALKI1 1 -2
Southern Transfer Alternative
Tunneling Alignment (Alternatives 2 and 3)
ALKI1
The final EIS has been revised in response to written comments during the comment period
and testimony given at the public hearing. Chapter 7 includes copies of comment letters, the
public hearing transcript and Metro's responses to comments.
This SEPA document is also intended to satisfy federal requirements under the National
Environmental Policy Act (42 U.S.C. 4321 et. sea.), and applicable agency regulations. The
final supplemental EIS will serve as EPA's final environmental assessment under NEPA.
Changes and Refinements Made After Draft EIS was Issued
An addendum to the draft supplemental EIS, issued on January 16, 1992, described a third
alignment (Allentown /Interurban Avenue) and transfer system that could be used to
accomplish the transfer of flows to Metro's treatment plant at Renton ( "Southern Transfer ").
This alternative combines Metro's proposed Interurban sewer system improvement project
with the Alki southern transfer. An environmental checklist and SEPA Determination of
Nonsignificance was issued for the Interurban project in August 1991. The description of
the alignment and the evaluation of impacts is incorporated into the text of the final EIS.
In the draft EIS, the representative site considered for the west portal of the tunnel was at
the intersection of 59th Avenue Southwest and Southwest Admiral Way. Based on analysis
conducted since that time, Metro is now considering the intersection of 61st Avenue South
and Southwest Spokane Street as the west portal construction site. Further analysis by
Metro and its design consultants has shown that this location (approximately 3 blocks
southeast of the site previously considered) will result in lower construction costs and less
impacts to traffic during construction. Written comments and public testimony received on
the project demonstrated a concern for potential impacts to traffic at the intersection of
Southwest Admiral at 59th Avenue Southwest.
Because of the change in location for the west portal, the tunnel alignment has been
changed to follow Southwest Spokane Street right -of -way west and through Schmitz Park,
1 -3
intersecting the Southwest Hanford Street right -of -way further east near the northeast
corner of Schmitz Park.
Designation of a Preferred Alternative
On March 19, 1992, the Metro Council adopted Resolution 6335, which identifies
Alternative 2 as Metro's preferred alternative for the final EIS. Alternative 2 includes: the
stormweather plant at Alki, the small diameter tunnel through West Seattle, together with
the Allentown /Interurban Avenue alignment (combined Southern Transfer /Interurban project)
for the southern transfer to the Renton plant. This action was taken after review of written
comments and public testimony on the draft supplemental EIS on the Alki Transfer /CSO
Facilities Project, and was made pursuant to Metro Council Resolution 4480 (sections 4E &
7E), adopting policies and procedures implementing the State Environmental Policy Act.
Alternative 2 would avoid the potential destruction of important marine habitat (eelgrass,
geoducks, and other benthic organisms) which would occur under Alternative 4. Alternative
2 also avoids significant adverse impacts to recreational activities and resources along Alki
Avenue Southwest and Harbor Avenue Southwest under Alternative 1. The combined
Southern /Interurban project will minimize construction and operation costs and minimize
environmental impacts associated with construction through the Tukwila area.
Stormweather Treatment Plant
In 1988, the City of Seattle granted Metro a Plan Shoreline Permit for the conversion of the
existing Alki treatment plant to a stormweather facility. The permit was granted with
conditions limiting the size of the facility and imposing strict requirements for noise and odor
control, traffic and visual mitigation, and community improvements.
Under Alternatives 1, 2 and 4 (see below), Metro would convert the existing primary
treatment plant to a stormweather facility that would operate only intermittently during
extremely wet weather. The stormweather facility would provide temporary storage of
flows to be transferred for secondary treatment and primary treatment and disinfection of
excess flows discharged to Puget Sound.
The stormweather plant would operate about sixty times a year, generally in the winter
months. About half of the time, treated effluent would be discharged from the plant; on the
remaining days, the plant would only store the storm flows until capacity becomes available
in the transfer line. At times, the plant may operate for several days; at other times, it may
operate for only a few hours.
Plant operation would be automated. Operations staff would be able to monitor the
operation of the plant from Metro's regional treatment plant at Renton. A detailed
discussion of the proposed stormweather treatment facility and stormweather treatment
technologies is included in Chapter 3.
Alternatives
There are four alternatives presented for comparison in the EIS. The alternatives are
numbered and named for the alternative alignments which provide for the Alki to West Point
Transfer. There are three alternative alignments for the Southern Transfer. The Southern
Transfer is an element of each of the four alternatives for transfer to West Point. The
stormweather treatment plant at Alki is an element of three of the alternatives. Table 1 -1
shows the essential elements for each alternative.
ALKI1 1 -4
Alternatives 1, 2 and 3 involve transporting Alki base flows in a pipe across West Seattle.
All three alternatives would proceed through the Duwamish industrial area crossing
Longfellow Creek and across the Duwamish River, and placing flows into a major trunk line
in the West Point collection system, the Elliott Bay Interceptor (EBI). Alternative 4 would
transport Alki flows in a pipeline under Elliott Bay, tying directly to the West Point plant.
As discussed above, all four alternatives include the Southern Transfer. Three alternative
pipeline routes are considered from south Seattle that travel south through areas within the
City of Tukwila to Metro's treatment plant at Renton. This southern transfer system will
relieve the West Point system of the added flows from Alki thus minimizing the possibility of
increasing combined sewer overflows (CSO) or exceeding treatment capacity at the West
Point plant.
A detailed description of the alternatives and figures showing the location of transfer
alignments are included in Chapter 3. The location of pumping stations and pipeline
alignments for each alternative are subject to refinement in final design. The locations as
described provide general corridors for the purpose of environmental review. A summary of
other alternatives that were considered but eliminated from further evaluation are also
presented in Chapter 3. Each alternative is briefly described below.
TABLE 1 -1
Elements of Alternatives
ELEMENTS
Stormweather Plant
Transfer to West Point
Around Duwamish Head
Small Tunnel
Large Tunnel
Underwater to West Point
Southern Transfer
>; >'A LTERNATIV
1
X
X
X
2
X
X
X
3
(a)
4
X
X
X
(a) Demolition of existing Alki plant.
Alki to West Point Transfer
Alternative 1: Around Duwamish Head
Alternative 1 includes the stormweather plant at Alki with a new transfer pumping station
located at the northwest corner of the plant site. The force main would be constructed in
street right -of -way from the transfer pumping station northeast along Alki Avenue
Southwest, around Duwamish Head, southeast in Harbor Avenue right -of -way into the
Duwamish industrial area and then west under the Duwamish River connecting to the West
Point System at the EBI.
ALKI1
1 -5
Alternative 2: Small Diameter Tunnel
Alternative 2 is Metro's preferred alternative for accomplishing the Alki to West Point
transfer. This alternative together with the Allentown /Interurban Avenue southern transfer
system (see be /ow) completes Metro's preferred alternative for the Alki Transfer /CSO
Facilities Project. The alignments and elements of Metro's preferred alternative are shown in
Figure 1 -1.
This alternative includes the stormweather treatment plant at Alki but there would be no
new pumping station at the Alki site. A force main or gravity line would be constructed in
street right -of -way from the existing 63rd Avenue Pumping Station. A 6 -foot diameter
(inside dimension) tunnel would be constructed through West Seattle Hill along an alignment
below Southwest Spokane Street, Schmitz Park and Southwest Hanford Street. The tunnel
would end at the east portal near Harbor Avenue Southwest where a transfer pumping
station (Harbor Avenue Pumping Station) would be constructed. The pumping station could
be located on the east or west side of Harbor Avenue Southwest. The exact location will be
determined during final design.
From the new Harbor Avenue pumping station at the east tunnel portal, a force main would
be constructed in street right -of -way to West Marginal Way Southwest. From West
Marginal Way Southwest the balance of this alignment is identical to the previous
alternative.
If in the future a treatment plant was located in the Duwamish industrial area, this
alternative would allow for the abandonment of existing facilities at the Alki site. There
would be no permanent structure constructed at the Alki site and the 6 -foot diameter tunnel
is sized for potential transfer of all flows from the Alki service area.
Alternative 3: Large Diameter Tunnel
Under Alternative 3, the existing 63rd Avenue Pumping Station would be converted to a
diversion structure and a new gravity sewer would be constructed following the alignment
to the west portal, as described in Alternative 2, the small diameter tunnel. Alternative 3
includes a 25 -foot inside diameter tunnel constructed along the same alignment as
Alternative 2 and includes the new Harbor Avenue pumping station constructed at the east
portal of the tunnel.
Under this alternative, sufficient capacity would be provided in the tunnel so that storm
flows could be stored until it was possible to send them to the EBI. As a result, it would
not be necessary to have the stormweather plant at Alki, and the plant could be abandoned
and demolished.
Alternative 4: Underwater, Alki to West Point
As in Alternative 1, a transfer pumping station would be located at the stormweather plant
site. The force main would be constructed in street right -of -way north across Alki Avenue
Southwest and north offshore under Elliott Bay and Puget Sound to the West Point
Treatment Plant.
ALKI1 1-6
Southern Transfer
Because the West Point plant would not have capacity to treat the Alki flows, all alternatives
require a transfer of equivalent flows to the treatment plant at Renton, where there would
be capacity to treat the additional flows. This Southern Transfer would also offset increases
in combined sewer overflow (CSO) in the West Point system (e.g. along Duwamish
Waterway, EBI) that would otherwise occur as a result of the transfer of Alki flows to West
Point. One of the following alignments is required to complete each alternative.
Norfolk Street /Railroad
A force main would be constructed in street right -of -way from a new pumping station
(Norfolk pumping station) on the east side of the Duwamish River in the vicinity of Interstate
5 and South Norfolk Street, west to the railroad right -of -way, and south in railroad right -of-
way to Metro's regional treatment plant at Renton.
East Marginal Way /Interurban Avenue
A force main would be constructed in street right -of -way from the Norfolk pumping station
described under the Norfolk /Railroad alternative, west along Norfolk Street under 1 -5, south
along East Marginal Way South tunneling under the Duwamish River or bridging across to
Interurban Ave South, then aligned south along Interurban Avenue mainly in City Light right -
of -way, and east bridging across the Green River at Fort Dent Park to the regional treatment
plant at Renton.
Allentown /Interurban Avenue
This is Metro's preferred alternative for accomplishing the southern transfer of flows to
Metro's treatment p /ant at Renton. This system combines Metro's proposed Interurban
sewer system improvements with the Alki southern transfer.
Under this alternative, there would be no pumping station constructed in south Seattle
(Norfolk pumping station). An underground control structure would be constructed at
Metro's Henderson trunk at Airport Way South. From the control structure a gravity sewer
would be constructed south along street right -of -way and railroad right -of -way to
Allentown. The alignment proceeds through Allentown mostly in street right -of -way and
under the Duwamish River to Interurban Avenue South (Val Vue Connection) at the 42nd
Avenue Bridge.
From the Val Vue connection at Interurban Avenue the proposed conveyance system would
combine flows from the Val Vue Sewer District, Tukwila, and the Alki southern transfer.
The pipeline alignment proceeds along Interurban Avenue South to the treatment plant at
Renton, as described for East Marginal Way /Interurban Avenue. Flows would be pumped to
the treatment plant at Renton from the proposed pumping station constructed for the
Interurban project, located off Interurban Avenue South near Foster Golf Links, and Tukwila
City Shops.
Combining the Metro projects minimizes duration and extent of construction impacts
because only one construction phase would be needed instead of two, provides for
coincident benefits to the local sewer systems in the Tukwila area, and because Allentown
is currently unsewered, locating the trunk line through Allentown would facilitate future
ALKI1 1 -7
connection of a local sewer system for the area. One new Metro pumping station would be
needed compared to two, if the two projects are not combined.
The environmental checklist issued on the Interurban project in August 1991 is incorporated
herein by reference.
Impacts and Mitigation Measures
Table 1 -2 provides a summary and comparison of the impacts and mitigation measures for
the alternatives.
Significant Adverse Impacts that Cannot be Mitigated
With few exceptions, Metro would mitigate adverse impacts resulting from all alternatives.
However, construction of the underwater Alki to West Point alignment would produce some
loss and temporary displacement of benthic organisms in intertidal areas that could not be
avoided. Also, eelgrass at Alki Beach and at the South Beach of West Point would be
eliminated in the construction corridor. Over time, populations of organisms would
reestablish themselves in the construction corridor. To minimize these impacts, construction
activity would be limited to the smallest possible area.
The underwater Alki to West Point alignment would also impact aquatic habitats and fishing
activities during construction. Waterfowl, marine mammals and fish would probably avoid
the area during offshore construction. These impacts would be minimized through
appropriate schedule restrictions and best management practices.
For all of the alternatives, construction noise impacts in residential areas cannot be avoided
completely. Residences within 50 feet of construction would be subjected to noise levels
occasionally reaching 80 to 90 dBA (two to three weeks at any one point). Residents in the
area surrounding the proposed Alki, Harbor Avenue, and Norfolk pumping stations would
experience construction noise for about 18 to 24 months. Recreational use of parklands
and beach areas along the transfer alignments would be similarly affected by construction
noise and the presence of construction equipment.
Hauling of spoils from tunnel construction, particularly for Alternative 3 (large diameter
tunnel), would increase truck traffic. The majority of the truck traffic would occur at the
east portal, impacting Harbor Avenue Southwest, West Marginal Way and Southwest
Spokane Streets.
Significant Areas of Controversy and Uncertainty and Issues to be Resolved
Permits from Local Jurisdictions
After the final supplemental EIS is issued, Metro will select the alternative to be
implemented and will apply for land use, shoreline, and other permits and approvals as
required.
The proposed Alki stormweather treatment facility may require a project -level shoreline
permit and a council conditional use approval from the City of Seattle. The project -level
permit would be issued only if it is consistent with the plan -level permit conditions imposed
ALKI1
1 -8
by the City Council in 1988. Those permit conditions are included as Appendix A to this
EIS.
Depending on their location, the pumping stations may require shoreline and land use
approvals. Pumping stations are permitted outright as utility service uses in many shoreline
zones, if a shoreline location is required.
Metro would also apply to the cities of Seattle, Tukwila, Renton and other jurisdictions for
land use and shoreline substantial development permits in order to construct the conveyance
pipelines from Alki to the West Point system and from the West Point system to the regional
treatment plant at Renton. Some of the conveyance alternatives could also require permits
from the U.S. Army Corps of Engineers.
Additional information on applicable land use and shoreline regulations, permits, and
approvals is presented in the land use appendix bound in this EIS.
Documents Incorporated by. Reference
See Fact Sheet.
ALKI1
1 -9
4 ‘ METRO
Alki Transfer /CSO
Facilities Project
Figure 1 -1
Metro Preferred Alternative
TABL1
_
-
ELEMENTS OF
TRANSFER
SYSTEM
Length of Pipeline
ENVIRONMENTAL
IMPACTS
Earth/Soils
Includes
Stormweather Plant
and new Alki Pumping
Station
30,000 feet
Temporary
construction impacts
include: increase in
surface runoff and soil
erosion due to
removal of vegetation
and loosening,
exposure and
stockpiling of soils.
5,100 cubic yards of
spoils to be hauled.
During pipeline
excavation, there is
potential for
encountering
contaminated soils
and groundwater in
Duwamish industrial
area.
Includes
Stormweather Plant
and new Harbor Ave.
Pumping Station
23,000 feet
Same as alternative 1,
and
43,000 cubic yards of
tunnel spoils to be
hauled away.
No Stormweather
Plant; includes new
Harbor Avenue
Pumping Station
23,000 feet
Same as alternative 1,
and
303,000 cubic yards
of tunnel spoils to be
hauled away.
Same as Alternative 1
32,900 feet
Same as Alternative
1, except no potential
for encountering
contaminated soils.
Construction in
nearshore slopes at
Alki and West Point
may present potential
risk for subaqueous
slope movement
Use trench support system
(shoring/bracing/sheeting). Limit
area of ground surface disturbance;
provide erosion control; regrade and
drain slopes to limit landslide and
erosion potential; test soils for
contamination and dispose of
contaminated materials
appropriately.
TABLE 1-2
Comparison Of Alternatives
(Alki to West Point Transfer)
Energy
Requirement
Air
Quality/Odor
Alki Transfer
Pumping, would
consume an
estimated 677,579
kwh/year.
The stormweather
plant would use
70% less energy
(electricity and
natural gas) than the
existing primary
treatment plant.
Short-term
construction-related
impacts due to
emissions and
particulates from
vehicles and
machinery.
Congested traffic
and dust from
construction sites.
Along force mains,
there is potential for
odor emissions at air
release structures.
Odor release
potential at
stormweather plant
and pumping
station.
New Harbor
Avenue Pumping
Station would
consume an
estimated 700,000
kwh/year.
The stormweather
plant would use
70% less energy
(electricity and
natural gas) than
the primary
treatment plant.
Same as Alt. 1
except,
impacts are
concentrated at
tunnel portals
(especially east
portal) and truck
haul route from
portal.
Alternative 3
New Harbor
Avenue Pumping
Station would
consume an
estimated 740,000
kwh/year.
Same as Alt. 2,
except
no stormweather
plant.
Demolition of
existing plant would
have short-term
impact on air
quality from
increased dust.
•Alteinative4
. . . . . .
. . .
West Point
Alki transfer Pumping
Station, would
consume an estimated
880,894 kwh/year.
The stormweather
plant will use 70%
less energy (electricity
and natural gas) than
the existing primary
treatment plant.
Same as Alt. 1,
except
short-term
construction-related
impacts would be less
severe because only
small portion of
alignment is on land
(within the Alki plant
vicinity).
Use of high efficiency pumps, blowers and
motors.
Spray exposed soils with water to reduce
dust; clean streets around construction; wash
truck wheels and undercarriages; avoid
prolonged vehicle idling; minimize
construction vehicle emissions by using
well-maintained equipment.
Odor emissions along pipeline are controlled
by properly designing the pump station to
limit turbulence and the force main to prevent
turbulence and solids deposition. If needed,
chemicals may be added at the pump station.
Odor control structures (carbon adsorption
tanks) may be installed where necessary
along force mains.
Underwater pipeline (Alt. 4) would be
designed to prevent gas pocket formation.
The alignment would also benefit from
advanced odor control technology currently
designed for the West Point Treatment
unorade nroiect where it would discharge.
TABL1-2A
1 - 12
TABU -2A
1 - 13
TABLE 1-2
Comparison Of Alternatives
(Alki to West Point Transfer)
•
Water Resources
Long-term benefit from
substantial reduction in
discharge of pollutants and
reduction of CSO in Alki
service area to waters off
West Seattle and to Puget
Sound.
Potential runoff from soil
stockpiles at pipeline
excavations.
Potential for site runoff
(petroleum products,
solvents, etc.) when
placing pipeline under
Duwamish River.
Pipe will cross Longfellow
Creek which runs in a pipe
through Duwamish
industrial north of Spokane
St. If creek pipe is
damaged during
construction or materials
are otherwise introduced
to the stream, adverse
impacts to the aquatic
environment could result.
Potential for encountering
contaminated groundwater
in Duwamish industrial
area.
Same as Alternative 1.
Same as Alternative
1.
Demolition of existing
plant would provide
potential for runoff as
described in
Alternative 1.
Same as Alternative 1,
except no potential for
encountering contaminated
groundwater in Duwamish
industrial area and no
impact to Longfellow
Creek.
Possible temporary
resuspension of
contaminated sediments,
turbidity and decreased
dissolve oxygen
associated with Elliott Bay
and Puget Sound crossing.
Possibility of pipeline
rupture and associated
water quality impacts.
This alternative could
provide a net benefit to
CSO management in West
Point system.
Minimize width and depth
of trench excavation;
temporarily reroute surface
waters away from
excavation; secure all
stockpiled soils to minimize
erosion and turbid runoff;
good housekeeping
procedures at tunnelling
pits.
Impacts of construction to
soils and earth along
alignments can be mitigated
by imposing stringent
excavation procedures and
good management practices
by the contractor.
Under Alternative 4, the
design of the conveyance
line incorporates features
which substantially reduce
possibility of pipeline
rupture.
Note: For each alternative the southern Transfer will offset increases in CSO in West Point system.
1.=.0:.V.V27.
TABU -2A
TABLE 1-2
Comparison Of Alternatives
(Alki to West Point Transfer)
Biological
Resources
. ........
••11
10rpa iv
Construction-related
noise may have slight
impacts on wildlife in
area but impacts
would be temporary.
Minimal impacts on
vegetation and
wildlife due to limited
habitat. Construction-
related noise may
have slight impacts on
wildlife in area but
impacts would be
temporary.
Short-term disruption
of wildlife in the
Duwamish Head
Greenbelt.
Same as Alternative 2
and
demolition of existing
Alki plant would
include noise that
would temporarily
impact wildlife in
area.
Minimal impacts on
terrestrial vegetation and
wildlife due to limited
habitat. Construction-
related noise may have
slight impacts on wildlife
in area but impacts
would be temporary.
Potential short-term and
possible long-term
impact to organisms
which comprise the
benthic (i.e. geoducks)
community. Short-term
impact to vegetation in
intertidal and subtidal
zone due to construction.
Eelgrass habitat off Alki
beach and West Point
south beach will be
temporarily lost in
narrow construction
corridor.
Construction activities
would cause temporary
displacement of fish.
Beach trench would be backfilled
with same material that was
excavated. Benthic organisms would
recolonize the area within a few
years. Mitigation plant for replanting
could be used.
Metro will coordinate with affected
treaty tribes to minimize disruption to
fishing operations. An
operation/construction mitigation plan
will be developed in connection with
the affected tribes, as appropriate.
Riparian vegetation should be
promptly restored after construction.
Mitigation measures described under
earth and water resources would also
mitigate impacts to biological
resources.
In addition, Metro will require the
contractor to use sheetpiles for
pipeline construction through eelgrass
beds to limit the area impacted.
Construction would be done within a
short period of time. Metro will
coordinate with resource agencies
and affected tribes regarding
appropriate restoration plans.
1 - 14
'
.::
...i. . :
. . . .
...... ....]:::Alternative .1
.. . :: :.::: .. . ::. .:
Around tniVainiW. Head -
"'' - --',:: i-
-:— , -... :
....Alternative 2
..:......:.,..:..: .::. :::
„S Small Diameter Tunnel
: ,%-.. --- •,-.--:. •
, . ' . :
Alternative 3 •
:... : .: ......... ........: .: .
.Large Diame ...Tunnel.
'.-.-... ..'. .-::..,.:.- '/... .... :::::::::,.......
s''. '' ..'. :.• ....,':::-....::-' ..:.
Alternative
. • : .:..: ....
- _..:::.:
nde00;er.:Alki;..t
-:.-..: --, .- Point
8 0 ,P
.•.- . Potential
Mitigation Measure
Recreation
Construction of pipeline
along this alignment would
cause temporary noise,
dust restriction to parking
and traffic impacts to
recreation resources
located along Alki Beach
and around Duwamish
Head along Harbor Avenue.
Construction activities at
stormweather plant site
with associated noise,
traffic and dust would have
a temporary impact on Bar
S Playfield. Temporary
impacts to recreational
fishing.
Construction activities
at stormweather plant
and associated noise
and dust would have
a temporary impact
on Bar S Playfield.
Demolition of
stormweather plant
would cause short-
term impacts related
to noise, dust and
increased truck traffic
affecting the Bar S
Playfield.
Temporary noise, dust
and traffic disruption
in Bar S playfield area.
Approximately 200
feet of Alki Beach and
South Beach at West
Point would be
temporarily impacted
during pipeline
installation. There
would be some
access restrictions
and impacts to
parking.
Construction in parks would be timed
to avoid evenings, and weekends
which are times of peak use.
All existing recreational facilities
disrupted by pipeline construction will
be restored. Where conveyance lines
must pass near parks, access will be
maintained at all times.
Land Use
Construction impacts
(noise, dust, traffic) to
single-family residential
areas around Alki
Treatment Plant, along Alki
Avenue S.W. and Harbor
Avenue.
Stormweather Plant and
Pipeline alignment along
Alki Avenue S.W. are in
restrictive shoreline
environments where
Council land use approval
is required for shoreline
permit.
Short term impacts to
neighboring land uses
would include noise,
dust and traffic.
Impacts concentrated
at east portal of
tunnel.
Stormweather Plant
req
requires shoreline
permit under same
conditions as
Alternative 1.
Same as Alternative 2
but construction
impacts would last
longer due to larger
tunnel size.
Dismantling of Alki
Plant would eliminate
all long-term
operational impacts to
neighborhood.
Same as Alternative
1, except fewer
impacts to Alki
Avenue S.W. and no
impacts to Harbor
Avenue S.W.
Stormweather Plant
and underwater
pipeline alignment are
in restrictive shoreline
environment requiring
Council land use
approval for shoreline
permit.
Strict enforcement of required dust
control measures.
Maintenance of access and convenient
loading areas for business/residences.
See noise control measures below.
Coordination with permit agencies.
Construction easements from
appropriate local jurisdictions would
be obtained.
Metro will coordinate with neighboring
residential, business and community
groups and local jurisdictions to
assure that temporary land use
impacts are minimized.
TABL1 -2A
TABLE 1-2
Comparison Of Alternatives
(Alki to West Point Transfer)
1 - 15
TABLE 1-2
Comparison Of Alternatives
(Alki to West Point Transfer)
Noise
Construction noise
within Alki plant
structure and outdoor
construction noise
including excavation.
The types of
equipment used
during construction
would likely generate
noise in the range of
76 to 91 dBA at a
distance of 50 feet
from the source.
Short-term
construction noise
along pipeline route
by pavement breakup,
trench excavation,
pipe installation and
backfilling as well as
truck traffic including
employee vehicles.
Noise levels will range
from 81 to 91 dBA at
50 feet from source
with occasional higher
peak levels.
Similar to Alternative
1, except that noise
from tunnel
construction would be
concentrated at east
portal, and removal of
excavation material
would generate truck
traffic noise.
Some vibration from
tunnel boring may be
noticeable at surface.
Same as Alternative 2
and noise from truck
would occur over
longer period of time
due to larger tunnel
size.
Demolition of existing
Alki plant would result
in short-term
increased noise level.
Possible short-term
construction noise
impacts near offshore
staging areas.
Some nighttime
construction noise at
locations of intertidal
trenching and
offshore staging
work.
Possible short-term
pile-driving noise if
sheet piles used for
nearshore trenching at
West Point south
beach and Alki beach
near 64th Place SW.
Very slight increase of
cumulative
construction noise
impacts at West
Point.
Noise impacts
associated with
construction/
operation of
stormweather plant
and pumping station,
as described in
Alternative 1.
Design pump station to meet
applicable residential area noise
restrictions.
Restrict permissible construction
hours to minimize nighttime
construction noise.
Strict enforcement of noise
ordinance construction noise
restrictions.
Use temporary acoustical barriers, if
needed.
Ensure that truck drivers adhere to
posted speed limits.
If practicable, use vibratory pile
drivers for placement and removal
of piles.
As appropriate, notify nearby
residents when extremely noisy
work will be occurring.
TABU -2A
- •
=
TABLE 1-2
Comparison Of Alternatives
(Alki to West Point Transfer)
Aesthetics
Historical and
Archaeological
Resources
Temporary disruption
of aesthetic qualities
in the vicinity of the
Alki plant and along
Alki Ave. S.W. and
Harbor Ave. S.W.
during construction.
A new Alki transfer
pumping station
would be built within
the existing Alki plant.
Pipelines are buried,
no long-term impacts.
Known sites at Alki
Beach Park are along
this alignment.
Pipelines are buried, no
long-term impacts.
Harbor Avenue
Pumping Station built
at east tunnel portal.
No impact anticipated.
Same as Alternative 2.
No impact anticipated.
Same as Alternative 1,
except construction
impacts would occur
between Alki plant site
and Alki Avenue S.W.,
at 64th Place S.W.
Trenching along this
alignment could affect
known sites off Alki
Beach Park.
The Alki transfer pump station
would be designed in accordance
with plan level shoreline permit
conditions.
Landscaping of disturbed areas
would be initiated.
Harbor Avenue pumping station
would be designed to blend with
surroundings
Archaeological field
reconnaissance would be
performed prior to any
disturbance. Memorandum of
Agreement NOM would be
developed with the state office
of Historic Preservation, the
Advisory Council on Historic
Preservation, and affected tribes,
as appropriate.
TABU -2A
1 - 18
L.
TABL1-2B
TABLE 1-2
Comparison of Alternatives
(Southern Transfer)
ELEMENTS OF
TRANSFER
SYSTEM
Length of pipeline
ENVIRONMENTAL
IMPACTS
Earth/Solls
Energy
Requirement
Air Quality/Odor
Includes Norfolk Pumping
Station
21,000 ft.
There is a potential for
temporary increase in
surface run-off and soil
erosion.
585,000 kwh/year;
operation of Norfolk
pumping station.
Short-term
construction-related impacts
due to vehicle emissions,
congested traffic and dust
from construction site.
Long-term operation of
Norfolk pumping station
would not result in any
significant odor impacts.
Includes Norfolk Pumping
Station
22,500 ft.
During construction of
pipeline, there is potential
for encountering
contaminated soils along
East Marginal Way South.
Potential for temporary
increase in surface run-off
and soil erosion.
Same as Norfolk
Street/Railroad alternative.
Air quality impacts would be
the same as Norfolk
Street/Railroad alternative.
erur
23,300 ft.
Due to depth of gravity line,
potential for increase in
surface run-off and soil
erosion is greater.
730,000 kwh/year;
(combined southern transfer
and Interurban project).
Short-term construction-
related impacts due to
vehicle emissions, and dust
from construction site.
Flows from southern
transfer will contribute to
operation at Interurban
pumping station. No
significant odor impacts at
pumping station are
anticipated.
Common mitigation measures would be
same as with northern alignments.
Test fills for contamination and dispose
of contaminated materials appropriately.
Limit area of ground surface disturbance;
avoid construction in wet season;
provide erosion control; use trench
support system.
Use of high-efficiency pumps, blowers
and motors.
Mitigation would be similar to routes
under West Point Transfer.
Odor control facilities will be included in
the design of pump station and pipeline.
1 - 19
TABU -2B
TABLE 1-2
Comparison of Alternatives
(Southern Transfer)
Water Resources
Biological
Resources
Potential for contaminated
groundwater along South
Norfolk Street and
Burlington Northern
right-of-way.
Potential construction
impacts at Black River
crossing (e.g. increased
turbidity, decreased
dissolved oxygen level).
Potential impact to
wetlands areas along east
side of railroad
right-of-way. Potential
impacts could include loss
or reduction of vegetation
from turbidity/
sedimentation, disruption
of wetland hydrology and
loss of wetland function.
Groundwater is likely to be
encountered along this route
because of proximity to the
Duwamish River;
dewatering will be
necessary.
Potential for release of
turbid, sediment-laden
groundwater to local
drainage systems and the
Duwamish River and the
Green River.
Potential for encountering
contaminated soils and/or
groundwater is less on this
route than the Norfolk
Street/Railroad alignment.
Most sections of this route
follow public right-of-way
and existing arterials.
Therefore, impacts on
vegetation and wildlife
would be minimal.
Due to depth of gravity line,
there is potential for
significant dewatering.
Same as Norfolk/Railroad
Minimize width and depth of trench
excavation; temporarily reroute surface
waters away from excavation; jack
stream crossings where feasible; secure
all stockpiled soils to prevent erosion;
restore streambed crossings with
existing gravels; restore riparian
vegetation after construction.
On-site containment or treatment of
discharged groundwater will be
implemented.
Staging areas will be located sufficiently
distant from the river to avoid impacts
on water quality and riparian habitat
(S5 route).
Minimize construction impact on
wetland by limiting trenching activity to
a small area if wetland cannot be totally
avoided. Restore wetland areas to
prevent long-term erosion and siltation
(e.g. replacing wetland soils and plants,
enhancing wetland buffers).
1 - 20
Recreation
Land Use
No impacts on existing
recreational resources are
anticipated.
Short-term impacts on
surrounding land use during
construction of Norfolk
Pumping Station.
Some disruption of normal
daily street activities within
affected industrial and
commercial areas.
Potential impacts on
recreational facilities such
as Foster Golf Links,
pedestrian and bicycle path
along Interurban Avenue
(new Green River trail
system). Construction
through Fort Dent Park
would last 7-8 weeks.
Short-term impacts on
surrounding land use during
construction of Norfolk
Pumping Station.
Temporary construction
impacts on neighboring land
uses.
Potential for temporary
disruption of activities in
Tukwila's Pea Patch Park.
Same as East Marginal Way/
Interurban Avenue.
Temporary construction
impacts neighboring land
uses (residential Allentown).
To the extent possible, construction of
pipeline will be away from recreational
resources.
Other measures would include
scheduling construction to avoid peak
use period and maintaining public
access.
Strict enforcement of dust control
measures
Maintenance of access and convenient
loading areas for business and
residences.
See noise control measures below.
Metro will coordinate with neighboring
residents, businesses, BNR/Union
Pacific Railroad, King County Parks and
local jurisdictions to ensure that land
use impacts are minimized. (City of
Tukwila, etc.)
1-21
TABL1-2B
TABLE 1-2
Comparison of Alternatives
(Southern Transfer)
1 - 22
TABL1 -2B
—
Aesthetics
Historical and
Archaeological
Resources
No long -term impacts from
buried pipeline are
anticipated. A new Norfolk
pump station would be built
within the vicinity of
existing Norfolk regulator
and 1 -5.
During construction
aesthetic qualities in the
vicinity of the Norfolk
Pumping Station would be
disrupted. Aesthetic
impacts would not be
significant, due to
undeveloped industrial
character of area.
No known resources would
be impacted.
1118
terur6`ar`Av
...........................
During construction
aesthetic qualities in the
vicinity of the Norfolk
Pumping Station would be
disrupted. Aesthetic
impacts would not be
significant, due to
undeveloped industrial
character of area.
Same as Norfolk
Street/Railroad alternative.
No known resources would
be impacted.
entow
During construction,
aesthetic qualities of the
Allentown area would be
disrupted.
Aesthetic impacts along
Interurban Avenue would
not be significant, due to
the industrial character of
the area.
Aesthetic qualities of Fort
Dent Park would be
disrupted during
construction.
Same as Norfolk/ Railroad
and East Marginal Way/
Interurban.
Mi t i gation <`Me asur
::,.: .:.:::.
The new Norfolk pump station would
be as small as possible and designed to
be inconspicuous with a scale
compatible to nearby land use.
Where above the grade odor control
and /or venting is constructed, these
structures will be designed to blend in
with immediate surroundings. Plantings
would be used to screen and /or buffer
vent structures.
Same mitigation measures as described
for West Point transfer alignments.
1 - 23
•
TO:
Ross Earnst
Ron Cameron
Don Williams
Rick Beeler
:.;
MEMORANDUM
FROM: Denni Shefrin
DATE: 21 February 1992
SUBJECT: Alki Transfer /CSO Facilities Project
Southern Transfer Alignment
Attached for your information are additional comments prepared by
Gary Schulz. These comments will not be provided to METRO, but
where applicable, can be addressed during the permit review
process. The following local permits will be required for this
project:
Conditional Use Permit
Shorelines Substantial Development Permit
Land Altering Permit
Street -use Permit
Please provide me with any comments you may have concerning the
attached. Thank you.
TO:
MEMORANDUM
CITY OF t UKINILA
Denni Shefrin, Associate Planner 1- _D^AWNING DEPT.
FROM: Gary Schulz, Urban Environmentalist - DCD
2
3
. 11MEdRo
FEB 2 0 1992
SUBJECT: Metro's Alki Transfer /CSO Facilities Project /Southern
Transfer Alignment.
Even though these comments and observations are written after the
DEIS comment period, we will be able to incorporate them into the
permitting process. My initial comments (1/22/92) on this project
are included as items 1) thru 3). The comments listed below them
are based on review of Sensitive Areas maps and a site visit.
1) My first comment is actually an issue and originates from a
"sideline" point of view. I question the Metro Council's
decision to postpone the need expand the Alki facility for
secondary treatment in the area that contributes the high
flows, that is West Seattle. Even though alternative
treatment techniques and transfer routes are discussed, there
is no analysis of feasibility for facility expansion. This
could greatly reduce impacts and possibly the pipeline costs
and the inevitable cost over -runs.
The Norfolk St. /Railroad alignment is 1,500 feet shorter than
the Interurban Ave. alignment; however, will probably disturb
several wetlands some of which are "adjacent ". Filling or
dredging adjacent wetlands will first require an individual
permit from the US Army Corps of Engineers.
Check tunneling vs. bridge crossing at 42nd Avenue? Is it
feasible to use the bridge or upgrade the present bridge
instead of tunneling.
Southern Transfer Alignment - Sensitive Area Map Review
4) Section 3 - Wetlands #3 and #4 are identified along the
western side of Burlington Northern's railroad right -of -way.
I visited this site area because the proposed pipeline
alignment is also within the railroad right -of -way. Because
there is an existing gravel road that runs from Airport Way S.
to BN's railroad /truck shipping area, it seems possible to
avoid direct wetland impacts. The 48 -inch pipeline could be
installed within the developed areas of the right -of -way.
The area also has a designation of being a seismic prone
sensitive area. I do not know of any specific protective
measures that can be used for pipeline installation.
'
Section 10 - If tunneling is the only way to cross the
Duwamish River at the 42nd Avenue, there is the potential for
impacts to Watercourse *10 -1 (Southgate Creek). There is also
a seismic zone mapped within the Interurban Avenue corridor.
) Section 15 - The proposed pipeline route to cross the River
through Ft. Dent Park appears to be situated near Wetland #8.
In summary, since Tukwila is a permitting jurisdiction for this
project, I assume we will review the actual site plans. This will
allow staff to assess potential impacts and require appropriate
mitigation measures per the SAO.
February 13, 1992
Mr. Gregory M. Bush, Manager
Environmental Compliance Division
Metro, 821 Second Avenue, M.S. 120
Seattle, WA 98104 -1598
RE: Draft Supplemental EIS for Alki Transfer /CSO Facilities Proj
/Southern Transfer Alignment
As a follow -up to today's discussion with Ellis McCoy, I am
submitting to you additional comments not discussed in my letter to
you dated 12 February 1992. All comments below pertain to he
third southern transfer alignment.
Impacts to Foster Links Golf Course Operations
The FEIS should address anticipated impacts to the golf course. It
is anticipated that impacts would include access into the parking
area and potential disruption of business operations. The F IS
should discuss compensation proposed for the potential loss of
revenues, both for golf course operations and the concessionai•e.
De- watering /stock - piling
Discharge from de- watering would be limited to the Duwamish Riv =r.
Diversion to the existing detention pond located on the golf course
property must be avoided.
The FEIS should address if and where soil would be stock - pit =d.
Stock - piling should be avoided within the golf course, but would be
permissible within the Pea Patch Park site.
City Shops
City of Tukwila
6200 Southcenter Boulevard • Tukwila, Washington 98188 John W. R: nts, Mayor
The FEIS should address potential impacts to the City Shops located
south of Foster Links Golf Course, and how the impacts would be
mitigated.
Construction Schedule
The FEIS should include a brief discission on the expec•ed
construction period, phasing schedule, and the days and hours of
operation.
Pea Patch Park /Garden
Pedestrian access 'and parking should be maintained. The F:IS
Phone: (206) 433 -1800 • City Hall Fax (206) 433 -180
should discuss potential impacts if any, and the proposed
mitigation.
Once again, thank you for the opportunity to respond to the Draft
Supplemental EIS for this project.
Sincerely,
Denni Shefrin
Associate Planner
cc: Ross Earnst
Ron Cameron
Rick Beeler
Don Williams
Gary Schulz
Ellis McCoy
Paul Forsander
File No SEPA 92 -001
February 12, 1992
City of Tukwila
6200 Southcenter Boulevard • Tukwila, Washington 98188 John W. Rants, Mayor
Mr. Gregory M. Bush, Manager
Environmental Compliance Division
Metro, 821 Second Avenue, M.S. 120
Seattle, WA 98104 -1598
RE: Comments to Draft EIS for Alki Transfer /CSO Facilities Project
Dear Mr. Bush:
Thank you for providing the City of Tukwila an opportunity to
review and comment on the Draft Supplemental Environmental Impact
Statement (EIS) for the Alki Transfer /CSO Facilities Project and
the subsequent addendum dated January 16, 1992.
The City has evaluated each of the proposed alignments and has
concluded that the preferred alternative for the southern transfer
for the pipeline is that described as the third southern transfer
alignment in the 16 January addendum.
Attached is a memo to Denni Shefrin from Ron Cameron dated 10
February 1992 which discusses anticipated impacts and proposed
mitigation measures expected to be incorporated into the final EIS.
These issues are in response to staff concerns and concerns raised
by residents during the two Metro - sponsored public hearings.
Not addressed in either the memo or the January 16 addendum is the
presence of and potential impacts to city - designated wetlands.
Tukwila has recently adopted the Sensitive Areas Ordinance (SAO)
which allows disturbance to wetlands for essential utilities where
impacts cannot be avoided. Section 18.45.080 requires that all
construction must be designed to protect the wetland and its
required buffer. Following installation of utilities, wetlands
must be restored and revegetated. Metro will be expected to comply
with the provisions and intent of the SAO ordinance (to be mailed
separately).
Should you have further questions or need any clarification, please
don't hesitate to contact me at 431 -3663 or Ron Cameron, City
Engineer, at 433 -1639. Gary Schulz can be reached at 431 -3662 for
questions related to wetlands.
We look forward to working with you on this project.
Sincerely,
Phone: (206) 433 -1800 • City Hall Fax (206) 433 -1833
Denni Shefrin
Associate Planner
Attachment.
CC: Ross Earnst
Ron Cameron
Rick Beeler
Gary Schulz
Ellis McCoy
Paul Forsander
File; :No. ; SEPA: 92, -001::
To: Denni Shefrin, Associate Planner
From: Ron Cameron, City Engineer
Date: February 10, 1992
Subject: Metro Alki Transfer /CSO Facilities P
Project No. 91SW03
GEHIJN.1
FEB 12 1992
CITY OF TUKWILA
ANNIN R tEp bf 3
Ii
A gravity 48 inch sewer line from Norfolk to the Interurban pump sta-
tion at Volvo White is the preferred alternative for the significant
advantages that it will provide for Tukwila. It is referred to as the
yellow line alternative from the Metro maps. The force main red and
green line alternatives provide no advantages to Tukwila, the red line
is the eastern alignment along the BN tracks and green line is the
western alignment along E Marginal and Interurban.
Advantages of the yellow line include that it will eliminate the need
for three existing pump stations in Tukwila, provide the means to
serve Allentown with gravity sewer (otherwise a pump station will be
required for Allentown), results in constructing one major sewer
project along Interurban instead of two projects and the resultant
traffic congestion and inconvenience, and will have a lower on going
maintenance and operation cost than either the red or green line al-
ternatives. The yellow line provides substantial service advantage
that will prevent redundancy of projects and operating costs - for
Tukwila residents and all Metro users.
The red and green line force main alternatives will not allow gravity
connection such as in Allentown, will not eliminate the Metro, Valvue,
and Tukwila pump stations along Interurban, and will require higher
maintenance and operation costs. Allentown sewers will require a pump
station and probable separate crossing incurring additional economic
and construction disruption costs.
Ft Dent Green River Bridge
The river crossing to Fort Dent park is a primary issue that needs DCD
coordination. Both the King County Green River Trail project and the
sewer line will need to cross the river to get to Ft Dent park.
Parks, Public Works, Department of Community Development and Metro
would like a single bridge that serves the sewer and the trail.
A single bridge will reduce future maintenance and operation costs.
It will reduce the amount of floodway work. It could be processed by
interlocal agreement as a single shoreline permit. It would have less
disruption of Ft Dent Park and the river. Both proposed crossings are
within about 1/4 to 1/2 mile; the most economical crossing appears
to be at S 147 St. This further upstream for the trail requiring
additional trail easement but has the advantage of Metro sharing the
bridge costs. It is strongly recommended that only one bridge
crossing be allowed, at S 147 St for both Metro and the King County
Green River Trail. This is the location that Public Works, DCD, and
Parks is recommending.
Restoration
Service
Mitigations
To: Denni Shefrin, Associate Planner
From: Ron Cameron, City Engineer
Date: February 10, 1992
Subject: Metro Alki Transfer /CSO Facilities Project, pg 2 of 3
Streets, waterlines, sewer lines, drainage, gas, and communication
lines are required to be restored to current standards where the
Alki /CSO line disturbs them.
Access to homes, residences, businesses, and other accesses are to be
continously maintained. Closure during normal working hours (8am -
5pm) will be allowed by Tukwila Street Use Permit with 72 hours
advance notice to the affected access user, access to be restored at
night, alternative parking provided as determined for the Street Use
Permit, and pedestrian access maintained at all times. Businesses are
required to have continous access. Emergency access for fire, police,
and aid cars must be provided. Mail, UPS and other deliveries such as
fuel oil, and garbage needs to be provided. Particular attention for
the truck access on S 124 St to the BN yard is to be provided; all ef-
forts to keep this truck traffic on S 124 St without being detoured or
deterred is to be made. Detouring the BN truck traffic to other
Allentown streets will result in street damage requiring reconstruc-
tion as well as creating significant safety impacts requiring exten-
sive traffic control.
Street closure, detours, lane closures require an MUTCD traffic
control plan to be approved by the City Engineer. Construction
traffic control signs are to be reflectorized and illumination
provided where appropriate for vehicle and pedestrian safe movement.
Design review along Interurban and other streets will determine
specific engineering requirements when the design is further developed
for the yellow (or other) line alternative.
Proposed mitigations for disruption of service, access inconvenience,
construction of a permanent 6 foot barrier to any future east /west
lines between S 147 St and Norfolk, particularly along Interurban for
drainage to the river and in Allentown for future utilities have been
developed. They are intended to complement the Alki /CSO project and
have been formulated based on the comments from the Tukwila residents
attending the Foster Public Hearing and Allentown Open House meetings
conducted by Metro.
..
To: Denni Shefrin, Associate Planner
From: Ron Cameron, City Engineer
Date: February 10, 1992
Subject: Metro Alki Transfer /CSO Facilities Project, pg 3 of 3
Install any disrupted utility lines with the Alki /CSO line rather
than come back and "tear up" our street again.
For the Allentown route, a trunk line connecting to the Alki /CSO man-
holes and having stub outs for each lot is required to meet current
standards. The stub out locations will have to be determined by the
property owners. The trunk line would be installed along the streets
that the Alki /CSO line is installed as part of the Alki /CSO project.
Public Meetings for residents and businesses, utility coordination,
and news releases to keep the public informed and involved in the
project development and progress is needed. Presentations to the
Tukwila Utility Committee, Planning Commission, and Council will be
required.
' � «.....
To : ` Rick Beeler
Ross Earnst
�
City of Tukwila
6200 Southcenter Boulevard • Tukwila, Washington 98188
MEMORANDUM
Keep the Mayor's office apprised. Thanks.
Phone: (206) 433 -1800 • City Hall Fax (206) 433 -1833
JAN 3 0 1992
CITY OF TUKWjLA
PLANNING DEPT.
John W. Rants, Mayor
MINNIJNE
From: Mayor's Office
Re: Metro South Transfer Sewer Project
Date: January 30, 1992
The attached letter was provided to the Mayor and Council at last
Monday's meeting. It likely typifies the attitude of that
community with regard to the project. It can be fairly assumed
that their will be a high expectation of us to extract reasonable
mitigation from Metro on their (Allentown) behalf.
Ensure that you work out who will take the lead role in dealing
with both Metro and the community as the project progresses. We
don't want to get into a situation where we are reacting to
community demand for action. Take a proactive posture. This is
our first real test of the GMA requirement for interagency
cooperation. The installation of the line will not only represent
a disruption to the neighborhood, it could create long term
pressures for major land use changes.
Greg Bush, Manager
Environmental Compliance Division
Metro, 821 Second Avenue, M.S. 120
Seattle, WA 98104 -1598
Dear Mr. Bush:
12055 44th Avenue South
Seattle, WA 98178
January 26, 1992
SECERIED
JAN 2 9 is
TUKWiLt,
. J!3f..J.G WORKS
As residents of the Allentown area we wish to register our
concerns regarding the Alki Transfer /CSO Control Facilities
Project option involving Allentown. This is referred to in the
Metro literature as the "Southern Transfer Through Allentown"
option.
Having attended the public meeting of January 22, we believe we
understand the reason for the proposed routing through Allentown.
However, we question the advisability of disrupting the residents
of the seventy -five homes on 43rd and 44th Avenue South and South
122nd this route will affect, unless this disruption can be
mitigated in some way. The seventy -five homes along the
construction route do not include the general neighborhood
disruption that will be experienced by all the residents of the
Allentown area due to the closure of roads, detouring, increased
construction traffic, noise, and dust.
While your literature suggests possible benefits, "Also the
project may offer benefits to the City of Tukwila's local
wastewater collection system, including the ability to use the
new gravity line to provide sewer service to the Allentown area
in the future (the area is currently unsewered)." This seems a
leap of faith to those area residents so seriously disrupted. If
benefits are real with this routing, they should be defined and
quantified.
We request those Allentown residents along the construction route
who will suffer the most severe impacts during construction be
provided some form of compensation for this disruption. Along
with providing the possible future access to hook up to the
gravity line, we believe other improvements should be made while
the road is under construction. Improvements could include paved
streets, sidewalks and curbing; underground utilities; improved
water lines; and storm water drainage.
We hope Metro and the City of Tukwila will develop a
comprehensive plan in which improvements to the area can be made
in the most cost - effective, least disruptive manner. The
inconvenience to the residents of Allentown for a sewer line that
does not benefit them directly is too much to ask. Please work
together to provide the residents assured sewer access and local
improvements in return for the inconvenience and disruption the
project will cause.
cc: Wally Rants, Mayor
City of Tukwila
tion Cameron,; City Engineer
City of : Tukwila
Daniel Aragon, President
Duwamish Improvement Club
Very truly yours,
Allan Ekberg, Council President
City of Tukwila
..
Ray and Joy Jenne
cwd
soi
Earl Clymer, Mayor
January 29, 1992
Gregory M. Bush, Manager
Environmental Compliance Division
Municipality of Metropolitan Seattle
821 Second Avenue M.S. 120
Seattle, WA 98104 -1598
Attention: Ellis Mc Coy
TRANSMITTED BY US MAIL AND FAX (684-1900)
Reference: REQUEST FOR EXTENSION TO COMMENT PERIOD FOR
Drat Supplemental EIS for Atki Transfer /CSO Facilities Project
CHT RENTON
Planning /Building /Public Works Department
Lynn Guttmann, Administrator
Dear Greg:
The City of Renton hereby requests at least a two week extension to the public comment period for the
Draft Supplemental EIS for Alki Transfer /CSO Facilities Project. We request additional time to Investigate
the issue of whether the Southern Transfer was considered adequately in the FSEIS for the Renton Plant
expansion. We also request an extension to coordinate our comments with the City of Tukwila. Please
inform us if there are any additional addenda and /or public meetings on the project.
Sincerely.
Donald rickson, Se
for the
Environmental Review Committee
cc: Deni Shefrin, City of Tukwila Fax 431 - 3665.
200 Mill Avenue South - Renton, Washington 98055
$METRO C :
Municipality of Metropolitan Seattle
Exchange Building • 821 Second Ave. • Seattle, WA 98104 - 1598
January 28, 1992
Rick Beeler
SEPA Official
City of Tukwila
6200 Southcenter Boulevard
Tukwila, WA 98188
Re: Extension of Comment Period on Draft EIS for Alki
Transfer /CSO Facilities Project
Dear Mr. Beeler:
Metro has received the City of Tukwila's request for
extension of the comment period on the draft Environmental
Impact Statement. We are pleased to grant a two week
extension to the deadline to allow for a more complete
analysis of the proposed alignments. Metro is also
coordinating with the Duwamish Improvemnet Club to schedule
another meeting for the residents of Allentown.
Per your request, Metro staff has contacted Denni Shefrin to
confirm this extension. Your written comments will be
accepted until February 12, 1992. Letters postmarked that
date will be accepted. If you have further questions,
please contact Ellis McCoy, Environmental Planner, at 684-
6779.
Sincerely,
� t3uzorz
Gregory M. Bush, Manager
Environmental Compliance Division
cc: Judy Cochran, Metro
Ellis McCoy, Metro
c.�. - rn ......w�..,.....�n.,,.�.ns.�x�+ eau+ r. wwar�m. n �.»....., w........—..._ ............... �. �«.. u.,..... �. v,.. w.... w. r....,.. r..+«. varnnwmw'. .n�++A..»........,.w.�.rr+M�;i. TiStth':'
Dear Mr. Bush:
Sincere
cc:
c..
City of Tukwila
6200 Southcenter Boulevard • Tukwila, Washington 98188 John W. Rants, Mayor
January 24, 1992
Mr. Gregory M. Bush, Manager
.Environmental Compliance Division
Metro, 821 Second Avenue, M.S. 120
Seattle,. Washington 98104 -1598
RE: Request for Extension to Comment Period for
Draft Supplemental EIS for Alki Trnasfer /CSO Facilities
Project
Because of issues raised by Allentown citizens at the public
meeting /hearing held on 22 January 1992 at Foster Golf Links, the
City of Tukwila is requesting a two week extension to the 29
January deadline to submit comments on the Draft Supplemental EIS.
It is also the City's hope that METRO will conduct a second
meeting /hearing for the benefit of citizens residing within and
around the Allentown area.
Because an addendum to the Draft Supplemental EIS was received 17
January 1992, a time extension would allow for a more comprehensive
analysis of both proposed alignments as well as afford citizen
input.
I would appreciate confirmation that an extension can be granted as
soon as possible. Please contact Denni Shefrin, Associate Planner,
at 431 -3663 to confirm or if you have further questions. Thank
you.
Rick Beeler, SEPA Responsible Official
Director of Community Development
EIPC -01 -92 File
Ron Cameron, City Engineer
Judy Cochran, METRO
Phone: (206) 433 -1800 • City Hall Fax (206) 433 -1833
��1
3 mETRD
Munic of Metropolitan Seattle
Exchange Building • 821 Second Ave. • Seattle, WA 98104 -1598
January 16, 1992
TO: Recipients of the Addendum to the Draft
Supplemental EIS and Preliminary Environmental
Assessment for the Alki Transfer /CSO
Facilities Project
- '5 QP)E S D )'5711311
To it AA) 6 1Z
Attached is an addendum to the Draft Supplemental EIS and Preliminary
Environmental Assessment for the Alki Transfer /CSO Facilities Project, prepared
in compliance with WAC 197 -11 -625. It provides additional information regarding
the alternatives presented in the EIS.
This addendum is being circulated to all recipients of the Draft Supplemental EIS
and other interested parties. No comment period is required for the addendum.
Written comments on the Draft Supplemental EIS for the Alki Transfer /CSO
Facilities Project will be accepted until January 29, 1992. Letters postmarked that
date will be accepted. Address written comments to:
Gregory M. Bush
Manager, Environmental Compliance Division
Metro, 821 Second Avenue, M.S. 120
Seattle, Washington 98104 -1598
For more information regarding the ALki EIS contact Ellis McCoy, Environmental
Planner, 684 -6779.
fsLi - , (6GE6 �sH)
1 GEN-Evii,i,,1
JAN 1 7 1992 1
i OF 1 ,- .:'.vvtLA
VLANNING DEPT.
ADDENDUM
TO THE DRAFT SUPPLEMENTAL ENVIRONMENTAL IMPACT
STATEMENT (under SEPA) AND PRELIMINARY ENVIRONMENTAL
ASSESSMENT (under NEPA)
FOR THE ATARI TRANSFER /CSO FACILITIES PROJECT
Introduction
This addendum to the draft supplemental environmental impact statement (EIS) for
the Alki Transfer /CSO Facilities Project provides additional information and
analysis to go with the alternatives presented in the EIS. Each alternative in the
EIS includes two possible alignments for a pipeline from the southern portion of the
West Point collection system to Metro's regional treatment plant in Renton. These
alignments are referred to as the "southern transfer" alignments in the draft EIS. In
the discussion of issues to be resolved, Metro identified the potential for combining of the southern transfer alignments (East Marginal Way /Interurban Avenue) Metro's Interurban project. Further analysis has shown that combining the
projects could produce the best combination of benefits for Metro and the Tukwila
area.
Combining the Interurban Project with the Alki Southern Transfer would produce a
transfer system and alignment slightly different from the two southern transfer
options described in the draft Alki EIS. The impacts of this third alignment are
within the range of impacts described for other alignments in the draft EIS.
The following information describes this third southern transfer alignment and the
environmental impacts associated with construction and operation of the pipeline
along this alignment. Impacts of the Interurban project were addressed in the SEPA
Determination of Nonsignificance issued by Metro on August 19, 1991.
Alignment
The new southern transfer alignment is called the Allentown /Interurban Avenue
alignment. This alignment includes a gravity sewer from south Seattle connecting to
a pumping station located off Interurban Avenue South at Foster Golf Links, and a
force main from the pumping station to Metro's regional treatment plant in Renton.
The pumping station location adjacent to Foster Golf Links is proposed for the
Interurban Project and would be enlarged to accommodate the combined project.
Unlike the other two southern transfer systems described in the Alki EIS, this
transfer system would not require constructing the Norfolk pumping station in south
Seattle. Figure 1 shows the Allentown /Interurban Avenue alignment and pumping
station location.
The Allentown /Interurban alignment begins at the Henderson trunk sewer where it
intersects Airport Way South. From there, a 48 -inch gravity sewer would be
constructed in the shoulder of Airport Way South continuing south along railroad
right -of -way to the Allentown area. Once at Allentown, the gravity sewer would be
installed in street right -of -way along 44th Avenue South, South 122nd Street and
43rd Avenue South. Leaving street right -of -way, the gravity sewer would then be
constructed along the western edge of the City of Tukwila's Pea Patch Park and
tunneled under the Duwamish River to the Val Vue connection at Interurban
Avenue South just east of the 42nd Avenue bridge leading into Allentown. Figure 2
shows the alignment through Allentown in more detail.
Once at the Val Vue connection, the route to the treatment plant at Renton follows
the alignment as described in the AIM EIS for the East Marginal Way /Interurban
Avenue southern transfer alignment. (See Draft Alki EIS, p. 3 -13.) From the Val
Vue connection south to the Interurban pumping station the gravity sewer would be
54 inches in diameter. The increase in size is required to accommodate flows from
both the Alki Southern Transfer and the Metro's Interurban Project. From the
Interurban pumping station, the force main would proceed along Interurban
Avenue South and through Fort Dent Park as described in the draft Alki EIS. The
Combined project would require installing two force mains to the regional
treatment plant at Renton along this alignment. One force main would serve the
Alki southern transfer and a separate force main would serve the Val Vue /Tukwila
service area.
Impacts and Mitigation Measures
The environmental impacts and mitigation measures associated with construction
and operation of this southern transfer alignment would be similar to the impacts
and mitigation measures described in the draft AIM EIS for the other southern
transfers. (See Draft Alki EIS, chapter 5.) The construction impacts are short -term
and include impacts such as: increased noise levels, increased traffic volumes and
traffic disruptions, and increased dust levels. These construction impacts and
associated mitigation measures are described in detail in chapter 5 of the draft Alki
EIS under each element of the environment.
The major difference in construction for this southern transfer alternative is the size
of the pipe that would be installed and the depth it would be buried. Most of the
pipe installation would be open -cut construction. The 48 to 54 -inch gravity pipe
requires a wider trench (10 to 12 feet) and a burial depth starting at 14 feet at
Henderson trunk, gradually increasing to 28 feet at the Interurban pumping station.
The larger pipe and deeper trench requires greater quantities of soils to be
excavated and stockpiled. The greater depth of excavation could also mean larger
excavation equipment, more dewatering discharge and shoring of excavation areas,
and longer construction at any one location.
Construction within the Allentown area could temporarily block residential
driveways, and temporarily reduce the number of parking spaces along 44th Avenue
South and 43rd Avenue South. Construction along Tukwila's Pea Patch park would
be timed to minimize impact to park activities. No long -term impacts to the park
are anticipated. To minimize impact to the Duwamish River the gravity sewer
would be tunneled under the river.
The alignment along Interurban Avenue South to the regional treatment plant at
Renton would serve both the Interurban Project and AIM southern transfer. The
greatest impact along this segment would occur in one of the southwest play field at
Fort Dent Park. Trenching across the play field may be required to install the force
main. A tunneling pit for the Duwamish River crossing would be located in the
field. Recreational use of the restored area could be delayed until the grass was
firmly reestablished over the construction area. Overall, the combined project has
2
substantial benefits in terms of minimizing construction impacts in the project area,
since there would only be one construction corridor and a sin &le construction phase.
Also the project may offer benefits to the City of Tukwila's local wastewater
collection system, including the ability to connect to the new gravity line and
abandon local pumping stations, and the ability to use the new gravity line to
provide sewer service to the Allentown area in the future (the area is currently
unsewered). The impacts of providing such service would be analyzed during future
environmental review. Because the combined project eliminates the need for one
pumping station (Norfolk), the overall operation impacts would also be less than
having two separate projects with two separate pumping stations. Construction and
operation impacts of this southern transfer alternative will be covered in detail in
the final supplemental EIS for the Alki Transfer /CSO Facilities Project.
ALKI TRANSFER/CSO
CONTROL FACILITIES PROJECT
0
3
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lil
M
2
C
STR
NORF
REGU
4mETRD
ALKI TRANSFER /CSO
CONTROL FACILITIES PROJECT
HENDERSON
TRUNK SEWER
ALLENTOWN/
INTERURBAN
ALIGNMENT
FIGURE 2
SOUTHERN TRANSFER
THROUGH AMNION
N
/
- l .
Municipality of Metropolitan Seattle
Exchange Building • 821 Second Ave. • Seattle, WA 98104 -1598
DETERMINATION OF NONSIGNIFICANCE (DNS)
INTERURBAN SERVICE AREA SEWER IMPROVEMENTS
PROJECT DESCRIPTION: Metro proposes to make improvements
to the existing sewage conveyance system which include
constructing a new pumping station located off Interurban
Avenue South at the south end of Foster Golf Links;
constructing a new gravity sewer line to the new pumping
station; and constructing a new forcemain from the new
pumping station site to the Metro treatment plant at Renton.
The new gravity sewer would be a 26 inch to 36 inch pipeline
replacing the existing Tukwila Trunk Sewer from the Val Vue
connection approximately 5,050 feet south parallel to
Interurban Avenue South. The new forcemain would be a 20
inch pipeline constructed along one of two alternative
routes to the Metro treatment plant at Renton. One
forcemain alternative travels east through Foster Golf Links
down railroad right of way and through Fort Dent Park. The
other forcemain route travels south along Interurban Avenue
and through Fort Dent Park.
PROPONENT: Municipality of Metropolitan Seattle (METRO)
LOCATION OF PROPOSAL, INCLUDING STREET ADDRESS, IF ANY: The
project is located in King County, Washington, section 14,
15, 23, and 24, , Range 4 East, Township 23 North. This
area encompasses part of the City of Tukwila from the 41st
Avenue Bridge along Interurban Avenue South to Fort Dent
Park and an adjacent portion of the City of Renton.
LEAD AGENCY: MUNICIPALITY OF METROPOLITAN SEATTLE (METRO)
The lead agency for this proposal has determined that it
does not have a probable significant adverse impact on the
environment. An environmental impact statement (EIS) is not
required under WAC 43.21C.030(2)(c). This decision was made
after review of a completed environmental checklist and
other information on file with the lead agency. This
information is available to the public on request.
There is no comment period for this DNS.
X This DNS is issued under 197 -11 -340 (2); the lead
agency will not act on this proposal for 17 days from the
date below. Comments must be submitted by Seldtembr ;
1991.
OCT 0 9 1991
Ciii
PLA , if.IING DEPT.
DATE: August 19, 1991
RESPONSIBLE OFFICIAL: Gregory M. Bush
POSITION /TITLE: Manager /Environmental Compliance and Right
of Way Division
TELEPHONE NUMBER: (206) 684 -1164
ADDRESS: 821 //'' Second Avenue, Seattle, Washington 98104
SIGNATURE: ✓'-'
You may appeal this
Executive Director,
Washington, 98104.
factual objections.
determination to Richard K. Sandaas,
at Metro- 821 Second Avenue, Seattle,
You should be prepared to make specific
Contact Ellis McCoy at 684 -1731.
L
01`,311\Via
[OCT 09 19 I1
CI1'1' uF I U\JVILA
PLANNING DEPT.
ENVIRONMENTAL CHECKLIST
INTERURBAN SEWER SYSTEM IMPROVEMENTS
I I1 i 1,„ ( i l '.'!_ 1 1 1'�l
A. BACKGROUND ` ... - -- ._
1. Name of the proposed project: CC Q 9 1991
Interurban Sewer System Improvements '�' ` � uK rvIL
E; a; KING DEPT.
2. Name of Applicant:
Municipality of Metropolitan Seattle (Metro)
3. Address and telephone number of applicant and contact
person:
Municipality of Tetropolitan Seattle (Metro)
821 Second Avenue MS 120
Seattle, WA 98104
Contact: Ellis McCoy
(206) 684 -1731
4. Date checklist prepared:
August 15, 1991
5. Agency requesting checklist:
Municipality of Metropolitan Seattle (Metro)
6. Proposed timing or schedule (including phasing, if
applicable):
Construction will begin after the appropriate permits are
obtained. Construction is expected to begin during the
summer of 1992, and is expected to last approximately 18
months.
7. Plans for future additions, expansion, or further
activity related to or connected with this
proposal:
There are no plans for future additions or expansion of
facilities to be constructed as part of this project.
Construction of Interurban Sewer System improvements may
coincide with construction associated with the expansion
of the Metro treatment plant at Renton.
1
e p lc .- -5-41
el.CE4P� � - t 3OC40d
8. Environmental information that has been prepared, or will
be prepared, directly related to this project:
Environmental information related to this project will be
included in the Interurban Sewer System Predesign Report
being prepared concurrently with this Environmental
Checklist by HDR Engineering, Inc.
Additional environmental information relating to the
project can be found in the following documents:
- Environmental Analysis - Task 390, Alki Transfer
- CSO Control Facilities Proiect (Municipality of
Metropolitan Seattle, 1990),
- Facilities Plan for Alki Transfer -
Facilities Project (Municipality of
Seattle, 1990),
- Predesign Report for Alki Transfer
Facilities Project (Municipality of
Seattle, 1990),
- Draft Supplemental Environmental Impact
Statement: Metro Treatment Plant at Renton - Phase
III Enlargement (Municipality of Metropolitan
Seattle, 1991), and
- Draft Environmental Impact Statement for Rabanco
/ Black River Waste Recovery Center (Rabanco
Regional Landfill Company, 1991).
9. Applications that are pending for governmental approvals
or other proposals directly affecting the property
covered by the proposal:
The City of Tukwila intends to improve sections of
Interurban Avenue S. from near 42nd Avenue S. to 52nd
Avenue S. This will include: bridge removal; widening
and paving; installation of curbs, gutters, sidewalks,
landscaping, light poles, signals; stormwater collection,
treatment and discharge; and installation of a storm
sewer trunkline. A Mitigated Determination of Non -
Significance (DNS) was issued July 20, 1991.
A small portion of one of the forcemain alternatives (See
11. below.) will cross the site of the proposed Rabanco
/ Black River Waste Recovery Center, just east of Foster
Golf Links and the Burlington Northern / Union Pacific
rail lines. The proponent is in the process of obtaining
permits for the project from the City of Renton and other
agencies with jurisdiction.
2
CSO Control
Metropolitan
- CSO Control
Metropolitan
Federal
Army Corps of Engineers
Section 404 Permit
Section 10 Permit
State of Washington
Both forcemain alternatives (A and B) will enter the west
side of the Metro treatment plant at Renton off Monster
Road S.W. where it will continue to a transition
structure on the treatment plant site. Metro is in the
process of obtaining permits for expansion of the
treatment plant from the City of Renton and other
agencies with jurisdiction.
10. List of governmental approvals or permits that will be
needed for the proposal:
The following approvals and permits are anticipated to be
needed for the proposal:
Department of Transportation
Highway Crossing Permit
Departments of Fisheries and Wildlife
Hydraulic Project Approval
Department of Natural Resources
Easement for Construction
Permanent Pipeline Easement
Puget Sound Air Pollution Control Agency
Notice of Construction and Application for Approval
City of Tukwila
Board of Architectural Review
Excavation Permit (bAy1C) pvL W_ `OM v
Shoreline Substantial Developmefit Permit
Street Use Permit
Utility Permit
Building Permit
Grade /Fill Permit
Right of Way Construction Permit
Necessary property rights for pump station and
facilities
3
City of Renton
Other
Shoreline Substantial Development Permit
. Right of Way Construction Permit
Grading Permit
King County
Easement for Construction
Grading Permit
Seattle -King County Health Department
On -Site Sewage Disposal System Permit
Burlington Northern Railroad /Union Pacific Railroad
Pipeline Crossing Permit
Permanent Pipeline Easement
Puget Western /City Light
Easement for Construction
Permanent Pipeline Easement
11. Brief, complete description of the proposal, including
the proposed uses and the size of the project and site:
The proposed Interurban Sewer System improvements include
the following three elements:
1) Construction of a new Tukwila Trunk Sewer from
near the Val Vue Connection to the new Interurban
Pumping Station at the south end of Foster Golf
Links;
2) Construction of a new Interurban Pumping Station
near the south end of Foster Golf Links; and
3) Construction of a new forcemain from the
proposed pumping station site to the Metro
treatment plant at Renton.
These improvements are shown in Figures 1 and 2.
The entire project is expected to take 18 months to
construct. The pumping station itself will take the full
18 months. Various segments of the Tukwila Trunk and
forcemain will take shorter periods of time; construction
of some elements may occur concurrently.
4
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FOOTBRIDGE
TUKWILA
PROPOS
- IN-TERUR
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EXIST
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ORCEMAIN ALT. "A"
BLACK RIVER
1000
2000
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FIGURE 1
Proposed Tukwila Trunk and
New Interurban Pumping Station
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EXIST
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PUMPI
STATION
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FIGURE 2
Proposed interurban Pumping Station
and Alternative Forcemain Alignments
Tukwila Trunk Sewer. The new Tukwila Trunk will begin at
the existing manhole T -14 (5A), about 50 feet south of
the Val Vue Connection near 42nd Avenue S. and Interurban
Avenue S. From this point, the new trunk will continue
south under the existing drainage swale in the old Puget
Sound Electric Railway right -of -way (now owned by Seattle
City Light). This right -of -way parallels Interurban
Avenue S. and is continuous to near S. 140th Street. The
new Tukwila Trunk will be installed adjacent to the
existing Renton ETS pipeline which is located in the west
side of this right -of -way.
The first 1,650 feet of the new trunk will be a 24 -inch
diameter concrete pipe installed at a depth of between 15
and 22 feet below grade. At the southern entrance to
Gateway Corporate Center, the diameter of the trunk will
increase to 36 inches. The trunk will continue south for
approximately 1,000 feet to the Interstate -5 (I -5) right -
of -way.
Construction of this section of the Tukwila Trunk (Val
Vue Connection to I -5) is expected to take about 3
months. Installation of the trunk sewer will require a
trench about 10 feet in width supported by sheetpiles.
It is expected that continuous dewatering will be
required.
It is estimated that 20 to 50 feet of pipe can be
installed each working day. As pipe sections are
installed, sheetpiles will be pulled and the trench will
be backfilled. About 100 feet of trench will be open at
any given time. The construction area will be about
1,000 feet by 60 feet along the alignment and will be
used for construction purposes (e.g. vehicles, equipment,
materials storage, parking). The width of the corridor
will narrow to 30 feet or less as it crosses local
streets and access points for local businesses.
The I -5 crossing will be accomplished by jacking or
tunneling a 660 foot, 60 -inch diameter casing pipe under
the existing structure and approach ramps. The 36 -inch
concrete trunk line will be installed within the casing
pipe. A jacking pit will be constructed south of I -5
near the entrance to Grantree Furniture. This pit will
be about 20 feet wide by 50 feet long and 25 feet deep.
Construction is expected to last 6 to 8 weeks. This
section will also require dewatering.
South of I -5, the 36 -inch trunk will continue in the City
Light right -of -way for approximately 2,400 feet to the
site of the new Interurban Pumping Station. Just south
of 1 -5, the new trunk sewer will be within 100 feet of
5
6
the Duwamish River for a distance of approximately 500
feet. Construction methods will be similar to those
described above. Construction of this section of the
trunk is expected to last about 3 months.
A new 12 -inch pipeline will be constructed across
Interurban Avenue S. in order to collect flows now served
by the existing pumping station. The existing station
will be removed to about three feet below grade,
backfilled and the site restored to a condition
Compatible with adjacent multi - family uses (i.e.
landscaped parking areas). Demolition of the existing
station is expected to take about one month and will
occur once other elements of the new Interurban Sewer
System become operational.
Interurban Pumping Station. The new Interurban Pumping
Station will be constructed adjacent to Interurban Avenue
S. near the south end of Foster Golf Links. This
location is just south of the golf course maintenance
road about 1,000 feet south of the existing pump station.
(The proximity of the existing pumping station to multi-
family residences and the potential for odorous emissions
is one of the reasons for relocating the pumping
station.)
The new pumping station will consist of an above grade
structure approximately 28 X 44 feet, averaging 14 feet
high (maximum height will be 16 feet). Below grade, the
structure will be about 40 X 44 feet. The pumping
station site will total approximately 13,000 square feet.
The new pumping station will be designed to convey an
ultimate peak flow of 10.0 mgd. Construction is
to last about 18 months.
Forcemain. There are two alternative routes for the 20-
inch forcemain from the new Interurban Pumping Station to
the Metro treatment plant at Renton. Forcemain
Alternative A runs east from the new pumping station,
parallel with the ETS line, through Foster Golf Links,
crossing the Duwamish River using the golf course
footbridge and then under the Burlington Northern / Union
Pacific rail lines. The forcemain will then continue
parallel to the Renton ETS line, southeast to the Black
River. The forcemain will be jacked or tunneled under
the Black River just east of the rail lines.
At this point, the forcemain will again cross the rail
lines to Fort Dent Park. It will be be trenched under
the Black River railroad trestles on the south side of
the channel. Once in Fort Dent Park, the forcemain will
run southeast along the west side of the railroad
embankment to•the southeast corner of the park, where it
will be jacked under the rail lines. Once on the east
side of the rail lines, the forcemain will again parallel
the.ETS pipeline, following the railroad access road to
Metro's treatment plant at Renton. The forcemain will
cross Monster Road S.W. and enter the treatment plant
near the main entrance gate. Total length of the
forcemain will be about 7,800 feet.
Forcemain Alternative B involves running the 20 -inch
forcemain southeast from the new Interurban Pumping
Station along Interurban Avenue S. for approximately
3,800 feet to a location across the river from the
southwest end of Fort Dent Park. This section of the
forcemain is to be installed in public right -of -way
obtained by the City of Tukwila from adjacent property
owners in trade for vacating Maule Avenue, a 20 -foot wide
right -of -way which bisects the properties adjacent to
Interurban Avenue S.
The forcemain will cross the Duwamish (Green) River to
Fort Dent Park via a new pipebridge or by tunneling under
the river. Although design is not yet complete, it is
likely that the bridge crossing will require footings on
each bank. Construction will require use of some
floating equipment although most of the work can be
accomplished using shore -based equipment. The tunneling
option will require staging areas and moderately deep
tunneling pits on each side of the river.
After crossing the Duwamish River, the forcemain route
will run in an easterly direction for about 1,750 feet,
crossing multi - purpose sports fields, parking areas and
the principal park access road.
It will be jacked under the Burlington Northern / Union
Pacific rail lines at the southeast corner of the park
near the soccer field. From this point, the forcemain
will follow the ETS right -of -way along the railroad
access road, crossing Monster Road S.W. into the
treatment plant near the main access gate. Total length
of forcemain alignment B will be similar to alignment A,
about 7,800 feet.
For both A and B alternatives, the 20 -inch forcemain will
be ductile iron, steel or concrete cylinder pipe,
installed in an open cut trench about 6 feet deep and 15
to 20 feet wide. It is unlikely that shoring of the
trench will be necessary. Because of the shallow depth
of the trench, dewatering is not anticipated. It is
B. ENVIRONMENTAL ELEMENTS
1. Earth
estimated that between 100 and 300 feet of pipe can be
installed each working day. Construction is expected to
last about 4 months.
Jacking pits will be required for railroad crossings on
each side of the railroad embankments. Because of the
shallow forcemain depth and the elevated railroad
embankment, these pits are expected to be shallow and
will not require substantial excavation. Jacking pits
for the Black River crossing (Forcemain Alternative A)
will be somewhat deeper because of the low elevation of
the channel.
For both forcemain alternatives, a below grade chlorine
injection facility will be installed adjacent to the
treatment plant entrance road in order to control odorous
gases. Following chlorine injection, the forcemain will
discharge into a new transition structure which will
strip hydrogen sulfide from the wastewater flow. All but
a small portion of the transition structure will be below
grade. A new 30 -inch diameter gravity line will convey
the flow from the transition structure to the plant's
influent control structure.
12. Location of the proposal, including street address, if
any, and section, township, and range; legal description;
site plan; vicinity map; and topographical map, if
reasonably available:
The project is located in King County, Washington,
sections 14, 15, 23, and 24, Range 4 East, Township 23
North. Figures 1 and 2 show the location of the Tukwila
Trunk, the new Interurban Pumping Station and the two
alternative forcemain routes (A and B) to the Metro
treatment plant at Renton.
a. General description of the site:
The project area is located in the central portion
of the Puget Sound Lowland. Various soils and
bedrock have been classified in the project area
and are generally described below.
8
r
Fill
Most of the lower Duwamish River Valley has been
extensively modified by filling and dredging
activities over the last century. Almost all
surficial soils in developed areas have been
disturbed to some extent by road grading and
filling of topographic depressions to provide level
structures.
Fills in the Duwamish Valley commonly consist of
loose or loose to medium dense, fine to medium sand
and silty sand placed hydraulically over areas that
were previously estuarine mudflats or low areas
along the Duwamish River. Fills, however can range
widely. Other fills have been placed to support
specific structures. These include the majority of
the Burlington Northern / Union Pacific Railroad
tracks south of I- 5 and many of the industrial and
warehouse buildings in the Duwamish Valley.
Alluvium /Estuarine Deposits
Alluvium is present in the small stream channels
and along the Duwamish River. These deposits are
usually thin and localized and range in gradation
from silt to sand and gravel.
Duwamish Valley alluvium and estuarine soils
consist predominately of fine and fine to medium
loose to medium dense sand, silty sand and silt.
In some areas finer - grained or organic alluvium/
estuarine soils have been observed. These
deposits include beds of clay, clayey silt, organic
silt and peat. In some cases the finer - grained
soils are very loose to loose or very soft to soft.
The thickness of the alluvium /estuarine deposits is
variable, but generally thickens toward the mouth
of the Duwamish River.
Vashon Till
Till is an unsorted mixture of clay, silt, sand,
and gravel deposited directly beneath a glacier and
densely compacted by the weight of the overriding
ice. Within the project area the till is usually
classified as a silty sand, sandy silt, or clayey
silt. Occasionally large boulders (up to
approximately 10 -feet in diameter) are found within
the till.
Bedrock
Tukwila Trunk
Bedrock outcrops appear along the slopes east of
the Duwamish River. These outcrops include rocks
of the Blakely Formation and older Eocene age
sedimentary rocks of the Tukwila and Renton
Formations. The Blakely Formation is an
interbedded sequence of marine siltstone,
sandstone, shale and conglomerate. The Tukwila and
Renton Formations are typically deeply weathered
and soft near the ground surface.
b. What is the steepest slope on the site (approximate
percent slope)?
Most of the area along the pipeline alignments and
in the vicinity of the new pumping station site
have slopes of between 0 and 5 per cent. Slopes to
30 percent occur at sites of engineered fill (e.g.
I -5 and railroad embankments) and along the
shoreline of the river.
c. What general types of soils are found on the site
(for example clay, sand, gravel, peat, muck)?
Specify the classification of agricultural soils
and note any prime farmland.
In the Preliminary Geotechnical Study. Tukwila
Trunk Sewer Rehabilitation Project, Tukwila.
Washington (Golder Associates, 1990), four strata
were identified in this portion of the study area.
These four strata generally correspond to those
described in B.1.a. above. It can be expected that
all of the above mentioned soil types will be
encountered during construction of the Tukwila
Trunk Sewer.
The ground water table appears to vary between
elevation 4 to 12 feet along the alignment (Golder
Associates, 1990). Based on excavations associated
with the Renton ETS line, contaminated soils are
not anticipated.
Interurban Pumping Station
The soils at the new Interurban Pumping Station
site are likely to be very similar to those
described above. Some or all of these soils may be
encountered during construction, depending upon the
extent of the excavation.
10
11
Forcemain
The soils encountered during construction of the
forcemain are likely to be similar to the soils
mentioned above in varying depths of thickness.
Fills near the Burlington Northern / Union Pacific
Railroad tracks are likely to be well compacted
sandy gravel.
d. Are there any surface indications or a history of
unstable soils in the immediate vicinity? If so,
describe.
The topography of the pumping station site and
pipeline corridors is relatively flat and not
subject to unstable soil conditions. At the same
time, much of the area consists of fill with a
relatively high groundwater table. These
conditions require special construction techniques
(e.g. dewatering and tight- sheeting).
e. Describe the purpose, type, and approximate
quantities of any filling or grading proposed.
Indicate the source of the fill.
For the Tukwila Trunk, an estimated 24,000 cubic
yards will have to be excavated. About 17,000
cubic yards of bedding and fill material will have
to be imported, probably from local gravel pits.
About 17,000 cubic yards of material will have to
be hauled away for disposal.
At the site of the proposed Interurban Pumping
Station, an estimated 2,800 cubic yards of material
will be excavated. Imported fill requirements will
be about 1,400 cubic yards; between 1,500 and 1,600
cubic yards of material will be hauled away for
disposal.
For the forcemain (both alternatives), about 10,000
cubic yards will have to be excavated. There will
be about 3,500 cubic yards of imported bedding and
fill material; about 3,500 cubic yards of material
will have to be hauled away for disposal.
All material shall be disposed of at an approved
- disposal site.
12
f. Could erosion occur as a result of clearing,
construction, or use?
Construction of the Tukwila Trunk, new pumping
station and forcemain will require excavation by
means of conventional equipment (e.g. hydraulic
backhoes, front -end loaders). Temporary increases
in surface runoff and soil erosion may occur as a
result of removal of vegetation, and loosening,
exposure and stockpiling of soils during
construction.
g. About what percent of the site will be covered with
impervious surfaces after project construction (for
example buildings or asphalt)?
Following installation of the new Tukwila Trunk and
the forcemain to the Metro treatment plant at
Renton, disturbed areas will be restored to their
original condition (e.g. paved, landscaped,
undeveloped). In these areas, there should be no
net change in impervious surfaces.
At the site of the new pumping station, it is
estimated that there will be an additional 9,000
square feet of impervious surface, consisting of
the structure and accessory parking areas.
h. Describe the proposed measures to reduce or control
erosion, or other impacts to the earth, if any.
Proposed measures to reduce or control the
project's short -term construction - related impacts
on earth and soils may include the following:
- designing dewatering systems to minimize
silt and turbidity in discharge;
- minimizing the size of disturbed areas along
the pipeline corridors and at the new pumping
station site;
- employing erosion control techniques such as
silt fences, hay bales, sedimentation ponds,
etc.;
- covering stockpiled soils with sheeting to
minimize erosion potential;
- minimizing excavation and other earthwork
within shoreline zones;
2. Air
- restoring disturbed areas (i.e. replanting,
repaving) as soon as practical after
construction has been completed;
- installation of the forcemain on the golf
course will occur within the February 1 -
March 15 period in order to enhance resodding
success and related site restoration efforts;
- compliance with City of Tukwila and City of
Renton erosion control requirements; and
- continuous supervision of construction
activities by Metro inspectors and enforcement
of Metro's erosion control - related
specifications.
a. What types of emissions to the air would result from
the proposal (e.g. dust, automobile, odors, indust
rial, wood smoke) during construction and when the
project is completed? If any, generally describe
and give approximate quantities, if known.
Over the 18 month construction period, exhaust from
construction vehicles, equipment and haul trucks
will be the primary sources of air emissions. This
will consist primarily of carbon monoxide and
hydrocarbons. Construction activities will also
generate minor amounts of dust and particulates.
Over the long term, there is potential for odor
generation in the Tukwila Trunk, in the wetwell at
the new pumping station, and in the forcemain.
Hydrogen sulfide and other gases can be generated
in wastewater facilities under low oxygen or anoxic
conditions. This is of particular concern when the
organic content of wastewater is relatively high.
For this project, odor generation is of concern at
the pumping station wetwell, where turbulence
releases gases to the atmosphere. Hydrogen sulfide
and other gases also tend to accumulate along the
forcemain, a low oxygen environment. At high
points along the forcemain, these gases tend to
accumulate and have the potential for restricting
flow. In addition, turbulence at the forcemain
discharge (i.e. transition from a pressure line to
a gravity line) causes release of accumulated gases
to the atmosphere.
13
b. Are there any off -site sources of emissions or
odors that may affect your proposal? If so,
generally describe.
The discharge of the rendering plant to the
Interurban collection and conveyance system creates
high odor potential at the existing Interurban
Pumping Station because of the high organic content
of the waste flow.
c. Describe proposed measures to reduce or control
emissions or other impacts to air, if any.
A number of measures can be employed to reduce or
control construction - related impacts on air
quality. These include:
In order
station,
installed
exchanges
from the
activated
- careful adherence to traffic control plans
in order to avoid extended slowdowns of local
traffic;
- avoidance of prolonged idling
construction vehicles and equipment;
of
- requiring contractors to maintain vehicles
and equipment in good operating condition;
- use of electrically - powered equipment where
practical;
- controlling dust by spraying exposed soils
during dry seasons as needed; and
- periodic cleaning of haul trucks and
roadways in the immediate vicinity of
construction sites to reduce generation of
dust.
Over the long -term, a number of odor control
measures will be implemented to reduce odor
generation at the new pumping station and along the
forcemain route.
to control odor within the pumping
separate ventilation systems will be
for wetwell and drywell (12 and 6 air
per hour, respectively). Exhaust air
wetwell will be scrubbed using an
carbon unit for odor control.
Chemical storage and feeding facilities will be
provided for odor and corrosion control in the
14
r
3. Water
a. Surface:
forcemain. Chemicals may include caustic soda,
sodium hypochiorite and iron salts.
There are three potential high points along the
alternative forcemain alignments: the golf course
footbridge (Alternative A), the Black River
pipebridge (Alternative A) and the Duwamish River
pipebridge (Alternative B). A gas release valve
will be needed to prevent gas pockets from forming
at these locations.
Gases from the golf course footbridge (Alternative
A) will be directed back to the pumping station for
scrubbing. At the Black River pipebridge
(Alternative A) and Duwamish River pipebridge
(Alternative B), gases will be drawn to the
shoreline for scrubbing with a small, below -grade
activated carbon unit and a small above -grade vent.
At the Metro treatment plant at Renton, facilities
will be provided to control the release of odorous
gases which have accumulated in the forcemain. A
chlorine injection point will be provided adjacent
to the north plant entrance road. This facility
will be located as far upstream as possible from
the forcemain discharge (though still on the
treatment plant site), in order to allow the
maximum amount of time for mixing and the
destruction of hydrogen sulfide.
A new transition structure will be installed to
create turbulence and strip hydrogen sulfide from
the wastewater flow. The gases generated in the
transition structure will be collected and passed
through an activated carbon scrubber before being
released to the atmosphere.
1. Is there any surface water body on or in the
immediate vicinity of the site (including
year -round and seasonal streams, saltwater,
lakes, ponds, and wetlands)? If yes, describe
type and provide names. If appropriate, state
what stream or river it flows into.
The principal surface water body located in
the vicinity of the project is the Duwamish
(Green) River. The project involves potential
bridge crossings of the river at the existing
15
Foster Golf Links footbridge (Forcemain
Alternative A) and a new pipebridge at the
southwest corner of Fort Dent Park (Forcemain
Alternative B). In addition, construction
activities (Tukwila Trunk) will occur within
200 feet of the Duwamish River near the Val
Vue Connection and just south of I -5.
The confluence of the Black River Channel and
the Duwamish River is located at the northeast
end of Fort Dent Park. Forcemain Alternative
A crosses over the Black River with a new
pipebridge just east of the rail lines within
the existing ETS pipeline right -of -way.
There is a large drainage ditch along portions
of the east side of Interurban Avenue S. near
the Gateway Park development and south of
Foster Golf Links. Proposed Tukwila Trunk
alignments will be located parallel 'to and
east of this drainage facility.
The City of Tukwila maintains a large drainage
facility near the Val Vue Connection. It is a
large open ditch / ravine which directs runoff
from near SR 599 under Interurban Avenue S. to
the Duwamish River. The new Tukwila Trunk
will cross under this ditch near the location
of the existing Tukwila Trunk line. Salmon
may utilize the extreme lower portions of this
drainage.
There is a large pond / retention basin on the
east side of Fort Dent Park near the base of
the railroad embankment. Forcemain
Alternative A will run between the pond and
the railroad embankment. The City of Tukwila
has established a 50 foot buffer requirement
around the pond. A variance will have to be
obtained from the city to construct within
this buffer.
2. Will the project require any work over, in, or
adjacent to (within 200 feet) the described
waters? If yes, please describe and attach
available plans.
The Interurban Sewer System Project will
require construction within 200 feet of
16
surface waters in several locations, depending
on which forcemain alternative is selected:
a) the Tukwila Trunk just south of the
Val Vue Connection (Duwamish River),
b) the Tukwila Trunk just south of I -5
(Duwamish River),
c) Forcemain Alternative A at the Foster
Golf Links footbridge (Duwamish River),
d) Forcemain Alternative A's new
pipebridge crossing (Black River), and
e) Forcemain Alternative B's river
crossing near the southwest end of Fort
Dent Park (Duwamish (Green) River).
These locations are shown in Figures 1 and 2.
Construction of the Tukwila Trunk in shoreline
areas will involve open cut construction
methods. The trunk will be installed at a
depth of between 15 and 22 feet below grade.
Tightsheeting of the trench and dewatering are
likely to be required.
It is expected that the 20 -inch forcemain can
be hung from the existing golf course
footbridge using shore -based equipment.
Impacts on the shoreline and riparian
vegetation should be minimal if staging areas
are set back from the river.
Similarly, the new pipebridge crossing at the
Black River will be accomplished using shore -
based equipment.
The new pipebridge at the southwest end of
Fort Dent Park will be constructed principally
with shore -based equipment with a smaller
amount of floating equipment. Impacts to the
shoreline and riparian vegetation can be
minimized if staging areas are set back from
the shoreline. Potential impacts will be
further reduced if this crossing is
accomplished by tunneling under the river.
17
18
3. Estimate the amount of fill and dredge material
that could be placed in or removed from
surface water or wetlands and indicate the
area of the site that would be affected.
Indicate the source of fill materials.
The new Tukwila Trunk will be constructed
across the City of Tukwila drainage facility
just south of the Val Vue Connection using
open cut construction methods. Construction
will occur during the dry season when flows in
this facility are at a minimum. Existing
soils will be excavated several feet below the
bottom of the ditch / ravine and clean
imported fill used for bedding material and
backfill. It is estimated that 400 cubic
yards of material will be excavated and 200
cubic yards of imported fill will be required
for installation of the 24 -inch sewer at this
location.
The new pipebridge crossing of the Duwamish
River near the southwest end of Fort Dent Park
(Forcemain Alternative B) may require a small
amount of dredging and filling as part of
bridge footings. The dredge and fill volumes
will be determined following design work if
this forcemain alternative is selected.
No other filling or dredging from surface
waters or wetland areas is anticipated.
4•. Will the proposal require surface water
withdrawals or diversion? Give general
description, purpose, and approximate
quantities, if known.
Depending on season, the project may require
temporary diversion of surface waters in the
City of Tukwila drainage facility just south
of the Val Vue Connection. Construction will
be scheduled during dry weather conditions
when flows are at a minimum. Any diversion is
expected to last no more than several days.
5. Does the proposal lie within a 100 -year flood
plain? If so, note location on the site plan.
A number of locations along the trunk and
forcemain alignments lie within the 100 -year
b. Ground
floodplain. See Figures 3 and 4 for specific
locations.
Forcemain Alternative B's new pipebridge
crossing to Fort Dent Park will be designed to
provide 6 feet of clearance above the 100 -year
flood elevation.
6. Does the proposal involve discharges of waste
materials to surface waters? If so, describe
the type of waste and anticipated volume of
discharge.
The project does not involve the discharge of
waste materials to surface waters.
1. Will ground water be withdrawn, or will water
be discharged to ground water? Give general
description, purpose, and approximate
quantities if known.
Dewatering will be required for installation
of the Tukwila Trunk from the Val Vue
Connection to the proposed pumping station at
the south end of Foster Golf Links.
Dewatering is also likely at the new pumping
station site.
Based on experience constructing the Renton
ETS line, it appears that it is unlikely that
groundwater will be contaminated, although
there may be some petroleum hydrocarbons in
the vicinity of the gas stations just north of
I -5.
Groundwater will be discharged to the sanitary
sewer, to local storm drainage facilities or
tight -lined to the Duwamish River depending on
location, volumes and quality. Groundwater
will be tested periodically over the course of
construction to determine the appropriate
method(s) of disposal. Discharge of
dewatering volumes to the sanitary system will
require a Metro Industrial Waste discharge
approval. The Department of Ecology will have
to approve discharge to the Duwamish River
and /or tributaries to the river.
No groundwater withdrawals will occur once
construction has been completed.
19
Figure 3. 100-year Flood Zones
Interurban North
If
APPROXIMATE SCALE IN FEET
SCO 0 SOO
• \
RM32
X
• -
zoNE x
•
— Z O E S\
1'4
• NMI) SifliiI111
- • -
ZONE AE
(‘;
ITN SCRjrn--11
1
Figure 4. 100-year Flood Zones
Interurban South
CITY OF TUKWILA
APPROXIMATE SCALE IN FEET
600 0 500
1-4 1---1
scjjj
19
- PLAcE--
ZONE ' X
RM331
N,
(
IIINIONVVASI[VVAILI1 Hit AIM' NI l't AN I
•
ZONE X
24 .
'
(
liM3.1
•
•
20
2. Describe waste material that will be discharged
into the ground from septic tanks or other
sources, if any. Describe the general size of
the system, the number of such systems, the
number of houses to be served (if applicable),
or the number of animals or humans the
system(s) is expected to serve.
High points in the forcemain at the Black
River pipebridge crossing (Alternative A) and
Duwamish (Green) River pipebridge crossing
(Alternative B) will collect gas bubbles.
These will be treated using an activated
carbon scrubber. Any sewage associated with
this gas will be discharged to local sewer
lines or treated in a small drainfield.
Wastewater volume is expected to be very low
(several gallons per day). Discharge of
sewage to a local drainfield will require an
On -site Sewage Disposal System Permit from the
Seattle -King County Health Department.
c. Water Runoff (including storm water)
1. Describe the source of runoff (including storm
water) and method of collection and disposal,
if any (including quantities if known). Where
will the this water flow? Will this water
flow into other waters? If so, describe.
During construction, runoff from construction
sites has the potential for reaching local
drainages, the Duwamish and Black Rivers and
Fort Dent Pond. The relatively flat
topography and the locations of much of the
construction which will occur indicates that
control of runoff can be accomplished with
careful attention to standard construction
practices.
In the immediate vicinity of surface water
bodies such as the Duwamish and Black Rivers
and Fort Dent Pond, special methods for
controlling runoff may be necessary to prevent
turbid runoff from reaching these waters.
The new pumping station is expected to add
about 9,000 square feet of impervious surface
to the area. This will slightly increase
storm runoff and drainage in the immediate
vicinity of the station, however, the impact
on existing drainage facilities will be minor.
2. Could waste materials enter ground or surface
waters? If so, generally describe.
21
During construction,
solvents, lubricants,
construction vehicles
potential for reaching
if contractors do
specifications and
practices.
petroleum products,
etc. associated with
and equipment have the
surface and groundwater
not follow project
standard construction
Once the system becomes operational, no waste
materials are expected to reach ground or
surface waters.
d. Describe proposed measures to reduce or control
surface, ground, and runoff water impacts, if any.
One of the principal objectives of this project is to
reduce combined sewer overflows to the Duwamish River by
expanding the capacity of the Tukwila Trunk. This will
result in improved water quality in the river,
particularly in the vicinity of Interurban Avenue S. and
42nd Avenue S.
Potentially adverse impacts on water quality associated
with the trunk sewer, pumping station and forcemain are
related to construction. The following methods can be
used to reduce or control these impacts:
- Minimizing the amount of area and vegetative
cover disturbed by construction;
- Maintenance of stream and river bank integrity;
- Limiting construction in sensitive areas (i.e.
wetlands, stream crossings) to dry seasons to
reduce potential for turbidity;
- Use of sedimentation controls such as hay bales,
rock filters, silt screens and fences, on -site
sedimentation basins, and drainage swales;
- Strict adherence to Metro guidelines for
dewatering; periodic testing of groundwater
quality; depending on volume and quality,
groundwater will be directed to sanitary sewers or
storm drains; if groundwater is contaminated, on-
site treatment may be necessary;
- As far as possible, construction vehicles and
equipment will be stored away from surface waters;
4. Plants
contractors will be required to handle any
petroleum products, lubricants, solvents, etc. in a
responsible manner in accordance with generally -
accepted construction practices;
- Stockpiles of excavated material and /or imported
bedding material will be stored away from surface
waters and will be covered when not in use;
- Disturbed sites will be restored with vegetation
(preferably native) as soon as practical after
construction has been completed; and
- Use of pervious paving materials (e.g.
"grasscrete ") where practical instead of asphalt or
concrete.
a. Types of vegetation found on site:
Deciduous trees: alder, maple, cottonwood, willow,
birch, various ornamentals
Evergreen trees: douglas fir, pine, ornamentals
Shrubs: various
Grass: various, ornamental (golf course, park)
Pasture: none
Wet Soil Plants: see description below
Water Plants: see description below
Vegetation along the Tukwila Trunk corridor, the
site for the new Interurban Pumping Station, and
two alternative forcemain routes is described
below.
Tukwila Trunk. Just south of the. Val Vue
Connection, there is a deep (20 feet) drainage
which crosses Interurban Avenue S. and the City
Light right -of -way, draining to the Duwamish River.
Running water was observed in the lower portion of
this drainage, an estimated 100 feet east of the
existing Tukwila Trunk line. Vegetation observed
included reed canarygrass and himalayan blackberry.
Much of the proposed alignment follows the City
Light right -of -way along Interurban Avenue S.
22
North of I -5, the eastern portion of the right -of-
way has been landscaped with lawn and small
ornamental trees. South of I -5 along the
pedestrian / bicycle path, vegetation includes
deciduous trees and grasses.
There is also a large drainage ditch which runs
about 20 feet east of Interurban Avenue S. and
parallel to it. The ditch includes associated
emergent /scrub -shrub wetland vegetation typical of
the region.
Just south of I -5, the Duwamish River flows close
(100 feet) to Interurban Avenue S. The vegetative
community adjacent to the river is dominated by
deciduous trees and shrubs.
The preferred pumping station site adjacent to
Interurban Avenue S. just south of the golf course
does not support any vegetation of significance.
Vegetation on Foster Golf Links consists primarily
of turf with a variety of both ornamental and
native trees. Douglas fir is common throughout the
course.
On the east side of the rail lines, the forcemain
corridor has been highly modified by industrial
activities. Only limited native vegetation is
present along the railroad embankments. The Black
River supports a very limited amount of riparian
vegetation (e.g. willows).
From the northeast corner of the Fort Dent Park,
Forcemain Alternative A will parallel the rail
lines (west side) to the southeast corner of the
park. For the most part, this area'consists of
large grassy areas with occasional deciduous (i.e.
maples, birch) and evergreen (i.e. Douglas fir,
pine) trees.
The forcemain will run between the railroad
embankment and the large pond along the eastern
margin of the park. The eastern margin of the pond
is located approximately 40 feet from the rail line
embankment; the area contains a pedestrian gravel
walkway and benches, and is landscaped with a
number of birch trees (25 -30 feet in height).
Forcemain Alternative B will run south from the new
pumping station along Interurban Avenue S. to a
location across the river from the south end of
23
Fort Dent Park. Vegetation along this alignment
has been highly altered by commercial, industrial
and transportation land uses and provides only
limited habitat for wildlife.
The proposed bridge crossing to Fort Dent Park will
encounter a variety of riparian vegetation,
including willows, alder, maple, and himalayan
blackberry. Once in Fort Dent Park, the forcemain
will cross to the rail lines along the south margin
of the park, crossing multi - purpose grass fields
with occasional deciduous and evergreen trees.
From the southeast end of Fort Dent Park, both
forcemain alternatives involve jacking the pipeline
under the rail lines and following the existing ETS
forcemain alignment to Metro's treatment plant at
Renton. This alignment follows an unpaved road
used for access from Monster Road S.W. to the rail
lines. Vegetation is very limited in this section.
b. What kind and amount of vegetation will be removed
or altered?
Tukwila Trunk. Construction of the Tukwila Trunk
will involve disruption of landscaped areas both
north and south of I -5. These areas consist of
grass and small ornamental trees. The large
drainage ditch adjacent to Interurban Avenue S.
will be avoided. Just south of the Val Vue
Connection, vegetation in the deep drainage ditch
(described above) which runs perpendicular to the
pipeline will be removed as the trunk is installed
below the bottom of the ditch. This section of
pipeline will be tight- sheeted, so the amount of
vegetation lost will be limited to a corridor of
about 15 feet.
Interurban Pumping Station. Construction at the new
pumping station site will involve removal of minor
amounts of vegetation on the 0.3 acre site. This
site has been highly altered and little vegetation
of significance is present.
Interurban Forcemain. Forcemain Alternative A will
involve removal of golf course vegetation (e.g.
grass, Douglas fir, ornamentals) principally
between the golf course footbridge and the railroad
embankment. The proposed alignment will cross
fairways 11 through 15, and may result the removal
of several Douglas fir trees (about 30 feet in
height). Greens will be avoided.
24
On the east side of the rail lines, the route will
follow the existing ETS pipeline alignment. North
of the Black River, much of this corridor has been
highly altered by industrial activities and little
vegetation is present along much of the route.
In Fort Dent Park, construction of Forcemain
Alternative A will involve additional removal of
grass through a 30 to 40 foot construction
corridor. As far as possible, existing trees and
shrubs will be avoided. However, Alternative A may
affect several Douglas fir trees (20 to 30 feet in
height) in the northeast corner of the park where
the forcemain crosses under the railroad tracks.
Depending on the alignment and distance from the
fenced property line, up to 13 maple trees and one
pine tree may be adversely affected along the
northeast perimeter of the park.
This alignment will run between the railroad
embankment and Fort Dent Pond. It is probable that
the forcemain can be installed without removing any
of the birch trees (22 trees between 15 to 30 feet
in height) located on the east side of the pond.
However, an undetermined number of trees may be
lost through root damage.
Southeast of the pond and east of the soccer field
and ball field (undeveloped), several Douglas fir
trees (20 to 30. feet in height) may be affected,
again depending on the final alignment.
Forcemain Alternative B will involve removal of
riparian vegetation on the river banks at the
proposed pipebridge crossing to Fort Dent Park.
Staging areas for construction of the bridge would
involve removal of lawn in Fort Dent Park in the
southwest portion of the park. It is likely that
the loss of vegetation associated with installation
of the forcemain from the river to the rail line
will be limited to loss of turf and occasional
small trees.
From the southwest corner of Fort Dent Park to
Metro's treatment plant at Renton, minor amounts of
grasses and perennials along the railroad access
road will be lost during construction. This area
has been highly altered and losses are not expected
to be significant.
Similarly, a small amount of turf, shrubs and small
trees may be lost during construction of the
25
forcemain and transition structure on the treatment
plant site.
c.. List threatened or endangered species or critical
habitat known to be on or near the site.
A search of the Natural Heritage Data System of the
Washington State Department of Natural Resources
was conducted in 1989 for another project which
included the Interurban study area (Municipality of
Metropolitan Seattle, 1990). The search for
significant natural features found "...no records
for rare plants, high quality native plant
communities of native wetlands..."
d. Describe proposed landscaping, use of native
plants, or other measures to preserve or enhance
vegetation on site.
A number of measures can be employed to minimize
construction - related impacts on vegetation:
- Where existing vegetation has been disturbed
as part of construction, these areas will be
replanted as soon as practical after
construction has been completed. Depending on
location, these plantings will be native or
ornamental grasses, groundcovers, shrubs and
trees;
- Forcemain alignments through the golf course
and Fort Dent Park will avoid removal of trees
wherever possible;
- As far as possible, trees lost to
construction will be replaced with trees of
similar size and species; additional trees may
also be planted to offset the size difference
between lost trees (20 -30 feet) and nursery
stock (14 to 16 feet); some trees may be moved
using a large tree "spade ", if transplanting
takes place during dormancy;
- Contractors will be required to take special
precautions to avoid impacts on wetland areas,
streams and drainages adjacent to construction
corridors (e.g. drainage along Interurban
Avenue S., Duwamish River shorelines, Fort
Dent Park Pond);
- Installation of the forcemain on the golf
course will occur within the February 1 -
26
1
5. Animals
March 15 period in order to enhance resodding
success and related site restoration efforts;
and
- In the event that streamside rehabilitation
is necessary, particular attention will be
given to a "beneficial" waterside planting
scheme designed to enhance the fishery related
habitat.
a. Circle any birds and animals which have been
observed on or near the site or are known to be on
or near the site:
Invertebrates: shellfish, insects, other
Fish: bass, salmon, trout, herring, other
Amphibians: frogs, salamanders, other
Reptiles: lizards, snakes, turtles, other
Birds: hawks, heron, eagle, songbirds, ducks, other
Mammals: deer, bear, elk, beaver, rabbit, other
Of the entire pipeline corridor, wildlife was
observed in greatest concentration in Fort Dent
Park Pond. Wildlife using the pond area on the day
of the field visit included Canada geese, mallards,
domestic ducks and geese, red - winged blackbirds,
song sparrows, gold finches, and frogs.
Salmon may utilize the extreme lower portions of
the large drainage near the Val Vue Connection at
certain times of the year.
b. List any threatened or endangered species or
critical habitat near the site.
The Washington State Department of Wildlife
reviewed their files for information on the
occurrence of special animals within or adjacent to
the Duwamish River corridor in 1989 as part of
another project (Municipality of Metropolitan
Seattle, 1990) . Two species were identified: the
great blue heron (Ardea Jerodias) and the bald
eagle (Haliaeetus leucocephalus).
27
The great blue heron has been designated a
"monitor" species by the Washington State
Department of Wildlife. The nearest major rookery
is located east of the Metro treatment plant at
Renton. Bald eagles are considered "threatened"
under both federal and state criteria. Bald eagles
are observed with some frequency in the Duwamish
Valley, recently in the vicinity of the heron
rookery cited above.
c. Is the site part of a migratory route? If so,
explain.
The Tukwila Trunk corridor, the new pumping station
site, and alternative forcemain routes are not
known to be specific parts of migration routes.
However, in a larger sense, the Duwamish Valley
supports a wide variety of migratory waterfowl,
raptors and songbirds.
d. Proposed measures to preserve or enhance wildlife,
if any.
Faciltiy sites and alignments have been carefully
selected to minimize impacts on vegetation and
wildlife. In addition, a number of spcecific
mitigation measures can be implemented to reduce
impacts on wildlife.
- Replanting of disturbed areas along pipeline
corridors as soon as practical will tend to
reduce impacts on wildlife;
- Where possible, replanting will use native
plant species, thereby enhancing wildlife
utilization; and
- Scheduling of construction work at river
crossings will be coordinated with fisheries
agencies and tribes in order to reduce
potential impacts on fishery resources.
6. Energy and Natural Resources
a. What kinds of energy (electric, natural gas,
oil, wood, solar) will be used to meet the
completed project's energy needs? Describe whether
it will be used for heating, manufacturing, etc.
During construction, fossil fuels will be utilized
to power construction vehicles, equipment and haul
trucks. Electrical energy may also be used to
28
7. Environmental Health
29
operate some construction equipment (e.g.
dewatering pumps).
Once operational, the Interurban Pumping Station
will reduce electrical energy requirements used to
operate pumps, controls, ventilation, odor control
and lighting by approximately 570,000 kwh /year,
compared to the existing pumping station.
b. Would the project affect the potential use of
solar energy by adjacent properties? If so,
explain.
The project will not affect the potential use of
solar power by adjacent property owners.
c. What kinds of energy conservation features are
included in the plans of this proposal? List
other proposed measures to reduce or control energy
impacts, if any.
Energy conservation measures will be incorporated
into the design of the pumping station and
forcemain. These will include: the use of energy
efficient pumps and motors; selection of energy -
efficient lighting and electrical systems; and
insulation of the structure and heating systems.
a. Are there any environmental health hazards,
including exposure to toxic chemicals, risk of fire
and explosion, spills, or hazardous waste that
could occur as a result of this proposal? If so,
describe.
The only hazardous materials used for construction
of the project will be fossil fuels (i.e. diesel,
gasoline) used to power vehicles and equipment and
various lubricants and solvents. It is possible
that inadvertent spills of these substances could
result in health hazards, however, the potential
for adversely affecting the environmental health of
workers and nearby residents is low.
The new pumping station will require chemical
storage and feeding facilities in order to control
hydrogen sulfide in the forcemain. Various
chemicals are typically used for this purpose
including caustic soda, sodium hypochlorite and
b. Noise
iron salts. A 5,000 gallon below grade storage
tank will be provided for storage of the specific
chemical selected for this purpose.
1. Describe special emergency services that
might be required.
No special emergency services will be
required. Standard first aid supplies will be
kept on hand at construction sites by
contractors.
2. Describe proposed measures to reduce or
control environmental health hazards.
Occupational Safety and Health Act (OSHA)
regulations regarding safety equipment and
procedures will be strictly enforced on
construction sites.
The storage and feeding facilities at the new
pumping station will be designed to meet
required safety provisions including secondary
containment, alarms, annunciator, and vents,
as well as spill response procedures.
Increasing the capacity of the Tukwila Trunk
will reduce the frequency and volume of
sanitary overflows to the Duwamish River.
This will have a positive effect on public
health and beneficial uses of the river.
1. What types of noise exist in the area which
may affect your project (for example:
traffic, equipment operation, other)?
There are a variety of noise sources in the
vicinity of the proposed project, however, the
existence of background noise will not affect
the project.
Tukwila Trunk
Automobile and truck traffic on Interurban
Avenue S., I -5 and SR -599 are the predominant
sources of noise in the vicinity of the
proposed Tukwila Trunk. Other noise sources
in proximity to the site include: rail traffic
on the Burlington Northern / Union Pacific
rail lines east of the site; and air traffic
30
Forcemain
Tukwila Trunk
31
from Boeing Field and Sea -Tac International
Airport. In general, background noise levels
are typical of commercial / industrial areas.
Interurban Pumping Station
Noise sources in the vicinity of the proposed
pumping station site are similar to those
sources discussed for the Tukwila Trunk.
Background noise levels are relatively high
because of the volume of truck traffic on
Interurban Avenue S. and the industrial
character of the area. Renton Concrete
Recyclers, located north of the Black River,
is a significant source of noise, both from
facility operation and haul truck activity.
The dominant noise sources in the vicinity of
the proposed forcemain are automobile and
truck traffic on Interurban Avenue South, I -5,
I -405, rail traffic on the Burlington Northern
/ Union Pacific rail lines east of the site
and the concrete recycling facility. More
distant noise sources include automobile and
truck traffic on SR -599 and air traffic using
Boeing Field and Sea -Tac International
Airport. Noise levels generally reflect the
industrial nature of the area.
2. What types and levels of noise would be created
by or associated with the project on a short -
term or long -term basis (for example:
traffic, construction, operation, other)?
Construction of the various project elements
will take place between the hours of 7:00 a.m.
and 7:00 p.m. on weekdays. No weekend or
evening work is anticipated.
Noise impacts will be generated by
construction activities and equipment and by
haul trucks and worker vehicles. Excavation
will be accomplished using conventional
equipment such as backhoes and graders. These
typically result in noise levels of
approximately 80 to 85 dBA at a distance
approximately 50 feet from the source.
Overall, based on the types of equipment and
32
activities anticipated, average noise levels
ranging from 76 to 91 dBA (at 50 foot
distance) can be expected.
Installation of sheetpiles will be
accomplished using vibratory pile drivers.
Use of vibratory pile drivers can reduce noise
levels approximately 30 percent at the source,
or about 30 dBA, compared to impact pile
drivers. Maximum noise levels expected are
about 70 to 71 dBA, 50 feet from the source.
Construction vehicles will generate noise on
area roadways. Heavy trucks (three or more
axles) generate about 83 dBA at 40 miles per
hour and 87 dBA at 60 mph, according to
Federal Highway Administration estimates. It
is expected that most truck traffic
approaching the site will be travelling 40 mph
or less. Consequently, peak noise levels
generated by heavy trucks will be up to
approximately 83 dBA. Project area roadways,
including Interurban Avenue S., currently
experience significant volumes of truck
traffic and associated noise levels. The
additional construction - related traffic
associated with the Tukwila Trunk is not
expected to cause noticeable noise increases.
Over the long term, operation of the Tukwila
Trunk will not generate any significant noise.
Interurban Pumping Station
Pumping station construction will last
approximately 18 months. The first phase,
lasting approximately four months, will
include excavation, foundation and structural
work. The second phase, lasting approximately
14 months, will include mechanical and
electrical work.
Noise impacts will be generated by
construction activities and equipment and by
haul trucks and worker vehicles. Excavation
for the pumping station will be accomplished
using conventional equipment such as backhoes
and graders, which typically result in noise
levels of approximately 80 to 85 dBA at a
distance of 50 feet from the source. Overall,
based on the types of equipment and activities
anticipated, average noise levels ranging from
76 to 91 dBA (at 50 foot distance) can be
expected. This noise level is roughly
consistent with the existing noise levels in
the area, which is heavily influenced by truck
traffic along Interurban Avenue S.
If ground water is encountered during
construction, installation of sheetpiles for
dewatering will be accomplished using
vibratory pile drivers. Use of vibratory pile
drivers results in noise levels of
approximately 70 dBA at a distance of about 50
feet from the source.
Approximately 60 one -way truck trips per day
will be generated during initial site
excavation, lasting approximately one week.
Most trucks will access the site via
Interurban Avenue S. Following initial site
excavation, material delivery truck trips will
average four to six one -way trips per day with
a peak of 20 one -way trips per day. Each
truck trip will generate peak noise levels up
to 83 dBA, however, this impact is not
expected to be noticeable to surrounding
receptors because of the existing high level
of truck use on Interurban Avenue S. Golfers
may notice the additional noise, especially
when playing near the construction site.
The completed pumping station will not result
in significant noise impacts. The pumping
station structure will be insulated to reduce
pump, generator and fan noise to the extent
that pump station operation will be
essentially indistinguishable from other local
noise sources.
Forcemain
Forcemain construction will generate noise
levels roughly similar to Tukwila Trunk
construction, described previously. The
duration of noise disruption along any given
section of forcemain will, however, be reduced
because less excavation will be required
(forcemain trench depth will be 5 to 6 feet
compared to 25 feet for the Tukwila Trunk).
For Alternative A, the nearest receptors
include the golf course, light industry
located along Interurban Avenue S., light
33
34
industrial uses adjacent to the Burlington
Northern / Union Pacific rights -of -way and
Fort Dent Park. Construction within the golf
course will occasionally place construction
activity within 100 feet of golf activity.
Peak noise levels at this site could reach 91
dBA on occasion.
Forcemain Alternative A will cross the
Duwamish -Green River on the existing foot
bridge located in Foster Golf Links. It is
expected that the forcemain can be hung from
the existing bridge. Consequently, noise
levels typically associated with new bridge
construction activities (e.g. floating
equipment, cranes, concrete trucks) are not
likely to occur. Pipe installation will be
accomplished relatively quickly using land -
based equipment.
The forcemain will then cross the golf course
where it will be bored or tunneled beneath the
Burlington Northern / Union Pacific rights -of-
way. Under this alternative the nearest
sensitive noise receptor will be users of the
golf course. Peak noise levels at this site
could reach 91 dBA on occasion. Some
disruption of golf activities may occur as
players wait for peak noise levels to subside.
Construction of Forcemain Alternative B will
result in noise levels similar in nature and
duration to those described above. This
alignment will require a greater amount of
pavement breakup than Alternative A. Pavement
breakup will generate noise levels up to 90
dBA at 50 foot distance for short periods.
Forcemain Alternative B involves a new
crossing of the Duwamish (Green) River near
the south end of Fort Dent Park. This will be
either a new pipe bridge or a tunnel under the
river. Peak noise levels could reach 100 dBA
if impact piledrivers are used for
construction of a new bridge. Additional
noise from floating construction equipment
(e.g. diesel engines, generators, cranes) will
also be generated. These types of equipment
can be expected to generate intermittent noise
levels ranging from 70 to 95 dBA at a distance
of 50 feet.
8. Land and Shoreline Use
35
If the forcemain is jacked under the river,
noise levels can be expected to be similar to
those which will occur when the forcemain is
jacked under the rail lines. For short
periods of time, jacking equipment will
generate high noise levels (e.g. greater than
90 dBA at 50 foot distance) for intermittent
periods. This noise will be noticeable to
Fort Dent Park users, particularly in the
south end of the park.
The completed forcemain will not generate any
significant long -term noise impacts.
3. Describe proposed measures to reduce or
control noise impacts, if any.
The following measures can be implemented to
mitigate noise impacts:
- Limiting construction of the various
project elements to the hours of 7:00
a.m. to 7:00 p.m. on weekdays;
- Use of properly sized and maintained
mufflers and use of engine intake
silencers and engine enclosures where
possible;
- Turning off equipment when not in use;
- Locating stationary construction
equipment away from sensitive receiving
properties where possible;
- Shielding particularly noisy equipment
by temporary attenuation barriers; and
- Substituting hydraulic or electric
models for impact tools such as jack
hammers, rock drills and pavement
breakers.
a. What is the current use of the sites adjacent
to the property?
Tukwila Trunk
The proposed Tukwila Trunk parallels Interurban
Avenue S., passing through commercial /light
industrial, residential and recreational areas.
North of I -5, the alignment is characterized by
commercial /light industrial uses. There are two
large office parks (Tukwila Business Park, Gateway
Corporate Center) and several gas stations /truck
stops.
South of 1 -5, the new Tukwila Trunk alignment will
continue south within the City Light right -of -way
between Foster Golf Links, a 71 -acre golf course
and Interurban Avenue S. The trunk will terminate
at the new pumping station at the south end of the
golf course. In addition to the golf course,
nearby land uses include an apartment complex and
commercial /light industrial uses.
Interurban Pumping Station
The pumping station site is
Interurban Avenue S. at the
Golf Links (south side of S.
proposed pumping station
undeveloped. Adjacent land
Gplf Links and the City of
shops to the east.
Forcemain
located adjacent to
south end of Foster
139th Street). The
site is currently
uses include Foster
Tukwila maintenance
There are two alternative routes for the 20 -inch
forcemain from the new Interurban Pumping Station
to the Metro treatment plant at Renton.
Forcemain Alternative A passes through areas
characterized by recreational (Foster Golf Links /
Fort Dent Park), transportation (Burlington
Northern / Union Pacific rail lines), industrial
(quarry) and utility (Metro treatment plant at
Renton) uses.
Similarly, Forcemain Alternative B passes through
areas characterized by recreational (Fort Dent
Park), transportation (Burlington Northern / Union
Pacific rail lines), commercial / industrial
(various) and utility (Metro treatment plant at
Renton) land uses.
b. Has the site been used for agriculture? If so,
describe.
Historically, the project site may have been used
for agriculture. However, the pumping station site
36
•
and Tukwila Trunk and forcemain alignments will be
constructed in areas which are already developed.
c. Describe any structures on the site.
The Tukwila Trunk and forcemain alignments will be
constructed almost entirely in private and public
rights -of -way. Structures along the alignments are
limited to utility facilities, paved roadways,
curbs and sidewalks.
The pumping station site is currently undeveloped.
d. Will any structures be demolished? If so, what?
The existing Interurban Pumping Station, located on
the west side of Interurban Avenue S. across from
Foster Golf Links, will be removed.
e. What is the current zoning classification of the
site?
Tukwila Trunk
The entire corridor for the Tukwila Trunk is
located within the City of Tukwila. North of I -5,
zoning is "M -1 Light Industry ". The M -1 district
is intended:
... to provide area for light industrial uses
which are non - nuisance activities in terms of
air and water pollution, noise, vibration,
glare and odor." (City of Tukwila, 1982).
The Foster Golf Links adjacent to Interurban Avenue
S., south of 1 -5 is zoned "R -A Agricultural." This
zoning designation is intended:
"...to preserve and protect existing
agricultural lands and uses; and to preserve
agricultural land which may be suited to
eventual development to other more intensive
urban uses." (City of Tukwila, 1982.)
The golf course is a conditional use under this
designation.
37
Interurban Pumping Station
Forcemain
The Tukwila Trunk corridor south of I -5 lies within
the "Interurban Special Review District ". This
district has been established because of
"...its unique physiography, the presence of
natural amenities and recreational facilities,
the historical relevance of the area to the
community and the contemplated future mix of
residential, commercial, industrial, and
public land uses... "(City of Tukwila, 1982).
Any development in the district, with the exception
of single family dwellings, must be reviewed and
approved by the Board of Architectural Review.
Zoning is "M -1 Light Industrial" at the pumping
station site. The purposes of this zoning
designation is as described above for the Tukwila
Trunk.
The pumping station site also lies within the
"Interurban Special Review District" (See above.).
The alternative forcemain alignments lie within the
Cities of Tukwila and Renton. City of Tukwila
zoning along Interurban Avenue S. is "M -1 Light
Industry "; zoning in Fort Dent Park is "R -A
Agricultural." Descriptions of uses permitted
under these designations have been described
previously for the Tukwila Trunk.
Much of the forcemain lies within the City of
Tukwila's "Interurban Special Review District."
Any development in the district, with the exception
of single family dwellings, must be reviewed and
approved by the Board of Architectural Review.
The section of the forcemain that follows the
Burlington Northern / Union Pacific rail lines
(east side) to the Black River is located in the
City of Renton. The current zoning designations
for this area are "L -1 Light Industrial" and "M -P
Manufacturing Park." The purpose of L -1 zoning is
"... to provide areas for low intensity, non -
nuisance generating in terms of odor, air and
water pollution, noise, vibration and glare,
industrial activities." (City of Renton,
undated).
The purpose of M -P zoning is
"...to provide for a wide variety of
industrial, transportation, service and office
activities whcih meet high operational,
development and environmental standards."
(City of Renton, undated).
f. What is the current comprehensive plan designation
of the site?
Tukwila Trunk
The current comprehensive plan designation for the
Tukwila Trunk alignment north of I -5 is light
industrial and commercial. South of I -5, the
comprehensive plan designation is parks and open
space, commercial and high density residential.
Interurban Pumping Station
The comprehensive plan designations for the new
Interurban Pumping Station site is light
industrial.
Forcemain
The City of Tukwila comprehensive plan designation
for the Forcemain Alternative A, on the west side
of the Duwamish (Green) River is light industrial.
On the east side of the river, Alternative A is
located in area designated parks and open space.
Sections of both forcemain alternatives (A and B)
are located in the City of Renton. The alignments
pass through areas designated manufacturing
park /multiple option, heavy industrial and
public /quasi- public.
39
g.
If applicable, what is the current shoreline master
program designation of the site?
Tukwila Trunk
Sections of the Tukwila Trunk which lie within 200
feet of the Duwamish River are subject to the
provisions of the City of Tukwila Shoreline Master
Plan (City of Tukwila, 1974). The extreme northern
section of the Tukwila Trunk near the Val Vue
Connection and a several hundred foot section just
south of I -5, lie within 200 feet of the Duwamish
River. The City of Tukwila shoreline master
program designation for the Green /Duwamish River is
"Urban Environment" (City of Tukwila, 1974).
Interurban Pumping Station
The Interurban Pumping Station site is more than
200 feet from the River and is consequently not
subject to the provisions of the city's shoreline
plan.
Forcemain
40
Sections of the alternative forcemain alignments
lie within 200 feet of the Duwamish River and are
designated "Urban Environment" by the Tukwila
shoreline plan. These include the existing Foster
Golf Course bridge and the proposed Fort Dent Park
bridge and their respective approaches.
The Black River in the City of Renton is designated
"natural" under the City of Renton Shoreline Master
Program (City of Renton, 1985). A section of the
Green River shoreline immediately southeast of Fort
Dent Park is designated "urban."
h. Has any part of the site been classified as an
"environmentally sensitive" area? If so, specify.
The Tukwila Trunk corridor lies within the
"Interurban Special Review District." Any
development in the district, with the exception of
single family dwellings, must be reviewed and
approved by the Board of Architectural Review.
In addition, the Green River has been designated a
"shoreline of statewide significance."
i. Approximately how many people would reside or work
in the completed project?
Interurban Sewer System improvements will not
require the presence of permanent staff. Metro
staff will visit the pumping station several times
each week for operation and maintenance purposes.
Pump repair and /or station refurbishment will
require maintenance staff to work on the pumping
station for several weeks every three to five
years.
j. Approximately how many people would the completed
project displace?
The proposed project will not displace any people.
k. Describe proposed measures to avoid or reduce
displacement impacts, if any.
Not applicable.
1. Describe proposed measures to ensure the proposal is
compatible with existing and projected
land uses and plans, if any.
The Tukwila zoning code does not explicitly
prohibit or permit pipeline or pumping station
within any particular zoning area. The proposed
Tukwila Trunk could be considered an "unclassified
use" defined as:
... unusual, large - scale, unique or special
form as to make impractical their being
included automatically in any class of use as
set forth in the various use districts
previously defined."
Construction of the Tukwila Trunk, new Interurban
Pumping Station and Interurban forcemain will
require Interurban Avenue Special Review District
review and approval. Review ensures the proposal
is compatible with and sensitive to existing
amenities and land uses.
The trunk and forcemain will not change land use
within or adjacent to the proposed pipeline
corridor.
41
r
Not applicable.
10. Aesthetics
42
Following construction, the Tukwila Trunk and
forcemain corridors will be landscaped to achieve
compatibility with the adjacent land uses.
Construction adjacent to the golf course will
require Interurban Special Review District review
and approval.
Following construction, the site will be landscaped
to achieve compatibility with the adjacent golf
course and the Green River Trail along Interurban
Avenue S.
9. Housing
a. Approximately how many units would be provided, if
any? Indicate whether high, middle, or low- income
housing.
The implementation of this project will neither add
new housing nor eliminate existing housing.
b. Approximately how many units, if any, would be
eliminated? Indicate whether high, middle, or low -
income housing.
Not applicable.
c. Describe proposed measures to reduce or control
housing impacts, if any.
a. What is the tallest height of any of the proposed
structure(s), not including antennas? What is the
principal exterior building material(s) proposed?
The new Interurban Pumping Station will average 14
feet in height; maximum height above grade will be
16 feet. The odor scrubber vent will be 8 to 10
feet above grade.
The principle exterior building material will be
concrete or CMU construction. The pumping station
will incorporate a public art element, probably on
the west side of the structure where it will be
visible from Interurban Avenue S. and the
pedestrian / bicycle path.
b. What views in the immediate vicinity would be
altered or obstructed?
No long term adverse impact on views will result
from implementation of the proposal. The pumping
station will alter views from the Foster Golf Links
to the industrial / commercial areas to the south,
however, the new station can be expected to improve
the appearance of this currently undeveloped area.
Views from Interurban Avenue S. will be altered, as
the pumping station structure replaces undeveloped
commercial / industrial areas, however, the new
pumping station will be designed to be compatible
with existing and proposed uses of the immediate
area.
The Tukwila Trunk and Interurban forcemain will be
underground except for the river crossings at
Foster Golf Links and the Black River (Forcemain
Alternative A) or Fort Dent Park ( Forcemain
Alternative B). At these locations, the 20 -inch
forcemain will be visible from the bridge
approaches and the river itself. The pipeline will
be designed to be as unobtrusive as possible. The
design of the golf course footbridge crossing and
the Fort Dent Park pipebridge crossing must be
reviewed and approved by the City of Tukwila under
provisions of the Interurban Special Review
District.
c. Describe proposed measures to reduce aesthetic
impacts, if any.
Tukwila Trunk
The proposed Tukwila Trunk will not change land use
within or adjacent to the proposed pipeline
corridor. The right -of -way is already in use by a
similar facility, the Renton Effluent Transfer
System (ETS).
Following construction, the Tukwila Trunk corridor
will be landscaped to achieve compatibility with
adjacent land uses, including business parks,
Foster Golf Links and the Green River Trail along
Interurban Avenue S.
Interurban Pumping Station
Construction at the pumping station site adjacent
to the golf course will require Interurban Special
43
Review District review and approval. Review
ensures the proposal is compatible with and
sensitive to existing amenities and land uses.
Following construction, the pumping station site
will be landscaped to achieve compatibility with
the adjacent golf course and the Green River Trail
along Interurban Avenue S.
Public art will be incorporated into the design of
the pumping station. This will be oriented toward
bicyclists and pedestrians using the trail along
Interurban Avenue S.
Forcemain
The proposed forcemain will not significantly
change land use within or adjacent to the proposed
pipeline corridor. The most significant change
will be the river crossing at the existing Foster
Golf Course footbridge or the new pipebridge /
footbridge at Fort Dent Park. Design of either of
these crossings will require review and design
approval by the City of Tukwila.
Following construction, the forcemain corridor will
be restored (i.e. replanted, repaved) to achieve
compatibility with adjacent land uses including the
golf course, the Green River Trail and /or Fort Dent
Park.
11. Light and Glare
a. What type of light and glare will the proposal
produce? What time of day would it mainly occur?
Construction is expected to occur during daylight
hours, typically between 7:00 a.m. and 7:00 p.m.
During late fall and early winter when days are
short, some temporary lighting may be used briefly
in the early morning or late afternoon. No large
scale lighting is anticipated.
Over the long -term, the completed project will not
produce any light or glare. Exterior lighting of
the pumping station will be subdued and limited to
that required for security purposes.
44
b. Could light or glare from the finished project be a
safety hazard or interfere with views?
The completed pumping station is not expected to
produce light or glare which could be a safety
hazard, nor will it interfere with views.
c. What existing off -site sources of light or glare
may affect your proposal?
There are no off -site sources of light or glare
which might affect the project.
d. Describe the proposed measures to reduce or control
light and glare impacts, if any.
The completed pumping station will utilize subdued
exterior lighting as needed for security purposes.
12. Recreation
a. What designated and informal recreational
opportunities are in the immediate vicinity?
Foster Golf Links, the Green River Trail, and Fort
Dent Park are the major designated recreational
opportunities in the area. The Duwamish /Green
River is the major informal recreational resource
in the area.
Foster Golf Links is a 71 -acre golf course located
between Interurban Avenue S. and the Duwamish
(Green) River. The golf course lies on both sides
of the Duwamish /Green river; the east and west
sides are connected by a footbridge.
A completed section of the Green River Trail runs
along Foster Golf Links to S. 139th Street. The
trail is designed for bikes and pedestrians.
Another trail segment, from S. 141st Street to Fort
Dent Park's entrance, is now being designed.
Fort Dent Park is a large athletic park owned and
operated by King County Natural Resources and Parks
Division. The park is bounded on the north, west
and south by the Duwamish -Green River and by
Burlington Northern / Union Pacific rail lines on
the east. The park has softball and soccer fields,
large grassy areas, children's play areas, picnic
tables and restroom facilities. There is a large
pond at the park's eastern edge near the rail line
embankment.
45
The proposed Black River Trail, part of the City of
Renton's Regional Trails Master Plan, is intended
to link Fort Dent Park, the Black River Forest and
the Empire Ridge Trail.
b. Would the proposed project displace any existing
recreational uses? If so, describe.
Tukwila Trunk and Interurban Pumping Station
South of I -5, the trunk will be constructed between
Interurban Avenue S. and the golf course.
Construction activities at the southeast end of the
golf course will include the pumping station and
sections of the Tukwila Trunk and forcemain.
Construction - related traffic, noise, odor and dust
may temporarily affect Foster Golf Links users to
some degree. At the same time, existing noise
levels on the course are relatively high because of
the proximity of the course to the railroad,
Interurban Avenue S., the Boeing Field flightpath
and I -5. Construction along the sidewalk may
displace Green River Trail users. Pedestrian and
bicycle traffic will be detoured around
construction.
Forcemain
Alternative A involves construction of an 20 -inch
pipeline east from the new pumping station,
parallel with the existing ETS line, through Foster
Golf Links, over the golf course footbridge to the
Burlington Northern / Union Pacific rail lines.
This alternative will disrupt the southern end of
Foster Golf Links, specifically the two holes (Nos.
11 and 16) located on either side of the footbridge
and the four holes (Nos. 12 through 15) located
south of the footbridge. Construction- related
noise, dust, odors and traffic will disrupt golf
course users.
The extent and magnitude of this disruption will
depend on the actual pipeline alignment, the
duration of construction and the time of year
construction occurs. Construction of the section
of forcemain which will be routed through the golf
course is expected to occur during the period
February 1 through March 15. This is a period when
golf course usage is comparatively low. Use of the
existing footbridge by golfers will be maintained
throughout the construction period.
46
In Fort Dent Park, construction - related noise,
dust, odors and traffic will disrupt weekday park
activities on the athletic fields and other park
areas. Specific park areas affected may include
the softball fields at the north end of the park;
the large pond and trail in the east central part
of the park; and the eastern end of the soccer
stadium.
The level of disruption will depend on the duration
of construction and the time of year construction
occurs. It is expected that construction within
the park will take from two to three months. It is
likely that construction will occur during the
period April through October.
Forcemain Alternative B involves routing the
forcemain from the new Interurban Pumping Station
site south parallel to Interurban Avenue S. to near
S. 149th Street, then east to the Duwamish River.
A section of the Green River Trail from S. 141st
Street to Fort Dent Park's entrance is now being
designed. Depending on when construction of this
trail section occurs, users may be disrupted during
construction of the forcemain.
Once in Fort Dent Park, the forcemain will
continue east across a large playing field to the
main access road. From there it runs south to a
location near the park entrance, where it turns
east to the Burlington Northern / Union Pacific
right -of -way in the southeast corner of the park.
Route selection through the park has been designed
to minimize disruption of park activities, however,
some disruption is likely to• occur, especially in
the west central portion of the park and along the
access road and parking areas. Vehicle and
pedestrian circulation within the park will be
maintained at all times. Construction will
typically occur during daytime hours on weekdays.
No construction is likely to occur during peak use
periods (i.e. weekends).
No long term disruption of recreational
opportunities will result from implementation of
the project.
47
c. Describe proposed measures to reduce or control
impacts on recreation, including recreational
opportunities to be provided by the project or
applicant.
Proposed measures to reduce or control the
project's short -term construction - related impacts
on recreation may include the following:
- minimizing the size of disturbed areas along
the pipeline corridors and at the new pumping
station site;
- minimizing excavation and other earthwork
within shoreline zones;
- restoring disturbed areas (i.e. replanting,
repaving) as soon as practical after
construction has been completed;
- scheduling construction in recreation areas
(i.e. Foster Golf Links, Fort Dent Park) for
non -peak use periods;
- maintaining access to recreational areas at
all times; and
- rerouting pedestrian and bicycle traffic
around construction sites using temporary
fences and signs.
13. Historic and Cultural Preservation
a. Are there any places or objects listed on or
eligible for national, state, or local preservation
registers known to be on or next to the site? If
so, generally describe.
Investigations associated with Metro's Renton ETS
and Metro treatment plant at Renton - Phase III
Expansion (Municipality of Metropolitan Seattle,
1984, 1991) projects identified several prehistoric
sites in the Duwamish Valley. One of these, Site
45KI267, is on a small hill northwest of the Metro
treatment plant at Renton. Cobble tools and
siltstone flakes and chunks were recovered which
appeared to be derived from an Olcott occupation
that dates 4,000 to 8,000 years ago. The site is
not eligible for the National Register of Historic
Places because of disturbance to the site. The
48
site is located in the proposal's general vicinity
but not in or immediately adjacent to any of the
proposed forcemain alignments.
A large portion of the proposed Tukwila Trunk and
Interurban forcemain corridors was surveyed for
cultural resources prior to construction of the
Renton ETS pipeline. Based on the results of that
investigation, it is unlikely that cultural
artifacts are present where the trunk sewer and
forcemain lie adjacent to the Renton ETS pipeline.
b. Generally describe any landmarks or evidence of
historic, archeological, scientific, or cultural
importance known to be on or next to the site.
The Duwamish Tribe occupied the Duwamish and Black
River Valleys and the lower portions of the Cedar
and White (Green) River Valleys. Extended villages
or bands occupied specific locations along the
rivers, selected for their importance for fishing
and hunting. The confluence of the Black /
Duwamish / White (Green) Rivers was one such
location, called "Mox La Push," a Chinook word
meaning "two mouths." The Duwamish villages
Sg S'quli'ls, and Tau we'dits were located
near the confluence of the rivers.
There are also a number of locations with religious
significance for the Duwamish Tribe. The knoll
north of the Metro treatment plant at Renton,
referred to as "swa'wa tix t d," is significant in
terms of Duwamish mythology. It is possible that
the hill was used for ceremonies and burials
(Municipality of Metropolitan Seattle, 1991).
The City of Tukwila Comprehensive Plan (1982)
provides a map of historic sites. The map depicts
areas and sites which are relevant to the city's
history. The following sites are located adjacent
to the proposed project:
Tukwila Trunk
Site Explanation
Puget Sound Also called the "Interurban",
E l e c t r i c the PSER was the region's first
Railroad mass transit system. The system
operated from 1902 to 1928.
49
Footbridge at
56th Avenue S.
Bridge at 56th
Avenue S.*
Historic boat
landing at 56th
Avenue S .
bridge. A small
c o n c r e t e
memorial marker
marks the site.*
Forcemain
Historic boat
landing, just
north of S.
144th Street
Fort Dent
Historic boat
l a n d i n g ,
adjacent to Fort
Dent Park Ball
Fields. A small
c o n c r e t e
memorial marker
marks the site.*
Black River
I n t e r u r b a n The first road linking Tacoma
Avenue S. and Seattle.
Bridge Bulkhead
Capsule 1985
indicating the
artifacts in the
reads, "Time
", possibly
placement of
bulkhead.
"Foster Landing at Foster
Homestead" commemorating the
flat bottom boats that sailed
between the Duwamish -Green and
Black Rivers between 1854 and
1886.
A Tukwila boat landing site once
used by small steamers traveling
the Duwamish -Green River.
Site of a blockhouse built
during the Indian wars, 1855-
1858 .
Commemorates the flat bottom
boats that went between the
Duwamish -Green and Black Rivers
between 1854 and 1886.
The Black River drained Lake
Washington before the lake was
lowered in 1916.
* Identified during field observations and not
identified on Tukwila's historic sites map.
c. Describe proposed measures to reduce or control
impacts, if any.
14. Transportation
If historical or archeological artifacts are
uncovered at any of the proposed construction
sites, construction will cease and the State Office
of Archeology and Historic Preservation immediately
contacted to determine the importance of the
artifacts. Additionally, the Muckleshoot tribe
will be contacted to assist in the determination of
the importance of any such artifacts.
a. Identify public streets and highways serving the
site, and describe proposed access to the existing
street system. Show on site plans, if any.
Major highways in the project vicinity include I -5,
SR 599, and I -405. Arterials serving the general
project vicinity include Interurban Avenue S., East
Marginal Way S., S.W. Grady Way and Empire Way S.
Access to Interurban Avenue S. and East Marginal
Way S. is provided by I -5 and SR -599. Access to
S.W. Grady Way is provided by I -405 or Interurban
Avenue S.
Construction vehicles will access the Tukwila Trunk
alignment via Interurban Avenue S. The proposed
Interurban Pumping Station will be accessed via
Interurban S. and S. 139th Street.
Access to forcemain segments on the west side of
the Duwamish River is provided via Interurban
Avenue S., S. 139th Street, and the entrance road
to Fort Dent Park. On the east side of the rail
lines, access to forcemain segments is provided via
Monster Road •S.W., Beacon Coal Mine Road, 68th
Avenue S. and Oaksdale Avenue S.W.
b. Is the site currently served by public transit? If
not, what is the approximate distance to the
nearest transit stop?
Metro's Tukwila Park - and -Ride facility is located
at Interurban Avenue S. and 52nd Avenue S. Seven
transit routes serve the Park - and -Ride daily.
Interurban Avenue S. is a "main transit street."
Transit stops are located on both sides of
Interurban Avenue S. from the Park - and -Ride lot to
I -405.
51
There is no transit service on Monster Road S.W. or
Oaksdale Avenue S.W. on the east side of the
Duwamish River.
c. How many parking spaces would the completed project
have? How many would the project eliminate?
Implementation of the proposal will not eliminate
parking spaces. The Interurban Pumping Station
will be designed with 3 to 4 parking spaces for
maintenance vehicles.
During construction, worker vehicles and
construction equipment will be parked on
construction sites or in designated parking areas.
Existing parking areas in commercial or industrial
areas will not be used by construction workers or
visitors. In Fort Dent Park, construction workers
will use designated parking areas only; these may
include small portions of existing parking areas
within the park. Existing parking areas at the
treatment plant will not be used by construction
workers, nor is any loss of existing parking
anticipated during construction of the forcemain.
d. Will the proposal require any new roads or streets,
or improvements to existing roads or streets, not
including driveways? If so, generally describe.
The proposal may involve improvements to the
proposed pumping station site's access road (S.
139th Street). This is an unimproved two -lane road
east of Interurban Avenue S. and is currently used
for access for golf course maintenance.
e. Will the project use (or occur in the immediate
vicinity of) water, rail, or air transportation?
If so, generally describe.
Neither the proposed Tukwila Trunk nor the
Interurban Pumping Station will be constructed in
the immediate vicinity of water, rail, or air
transportation. Forcemain alternatives, however,
involve a number of river and rail crossings.
Forcemain Alternative A involves river crossings of
the Duwamish (Green) River near S. 139th Street and
a Black River crossing just east of the BNRR right -
of -way. Forcemain Alternative B involves a
crossing of the Duwamish (Green) River near the
south end of Fort Dent Park. Each of these
proposed crossings will be bridge structures.
52
Neither the Duwamish (Green) nor the Black Rivers
support water transportation in this area although
recreational boating may occur periodically in the
Duwamish (Green) River. Any construction involving
floating construction equipment will be scheduled
so as not to interfere with any treaty protected
fishery which may occur in the Duwamish (Green)
River or the Black River.
If Forcemain Alternative A is selected, the
forcemain will be jacked under the Burlington
Northern / Union Pacific rail lines at three
locations: a) near the southeast end of Foster Golf
Links, b) just south of the Black River, and c) at
the southeast corner of Fort Dent Park. If
Forcemain Alternative B is chosen, the forcemain
will be jacked under the rail lines at the
southeast corner of Fort Dent Park. Jacking
techniques have been chosen in order to avoid any
disruption of rail traffic along these rail lines.
Construction activities are not expected to affect
any rail operations in this area.
f. How many vehicular trips per day would be generated
by the completed project? If known, indicate when
peak volumes would occur.
Tukwila Trunk
Once operation of the new Tukwila Trunk is
initiated,• there will be only occasional vehicle
trips for inspection and maintenance purposes.
Construction of the new Tukwila Trunk is expected
to take about 6 months. It is estimated that about
50 feet of pipeline can be installed each working
day. Heavy trucks will haul excavated material
(17,000 cubic yards) from the pipeline alignment
and haul bedding and fill material (17,000 cubic
yards), pipe and ancillary equipment to the
construction sites. This will amount to an average
of about 60 one -way haul truck trips per day over
the course of the construction period.
Construction workers are expected to number from 6
to 12 at any given time. Construction workers are
expected to drive private vehicles to the project
site, generating an additional 12 to 24 one -way
trips each day. Parking areas for construction
workers will be established within the construction
corridor in order to avoid use of existing parking
areas used by local businesses.
53
•
54
Construction of the Tukwila Trunk will slightly
increase traffic volumes on Interurban Avenue S.,
I -5, and to a lesser degree SR 599. Construction
is expected to occur during typical daytime working
hours. Nighttime or weekend work is not
anticipated.
Interurban Pumping Station
The completed pumping station will generate an
average of 5 one -way trips per week for inspection
and maintenance purposes. Every 3 to 5 years when
major pump repairs and /or station refurbishment
occurs, there will be about 4 one -way trips per day
for several weeks. It is also possible that
additional trips would be necessary in the event of
an emergency. All but emergency trips are likely
to occur during daytime working hours. Parking for
3 to 4 vehicles will be provided at the pumping
station site.
Construction of the pumping station is expected to
take about 18 months. Construction will generate a
maximum of 60 one -way truck trips per day during
the initial excavation phase (approximately 2
weeks). Following the excavation phase,
construction will generate approximately 4 -6 one -
way truck trips per day with an occasional maximum
of 20 one -way truck trips per day.
The number of construction workers will range from
an estimated 18 during excavation and structural
work to about 6 during final construction and
startup. Workers will generate up to 36 one -way
trips per day during the first 3 -4 months of
construction. After the first 4 months of
construction, workers will generate an estimated
12 -20 one -way trips per day. A designated parking
area will be established for construction worker
vehicles in order to minimize disruption at the
south end of the golf course. This parking area
will be established in a location which will not
hinder access to the south end of the golf course.
Construction of the new pumping station will
slightly increase traffic volumes on Interurban
Avenue S., I -5, and to a lesser degree I -405 and
Grady Way S.W. Construction is expected to occur
during typical daytime working hours. Nighttime or
weekend work is not anticpated.
Forcemain
After the forcemain becomes operational, there will
be occasional vehicle trips to various locations
along the alignment for purposes of inspection and
maintenance.
Construction of the forcemain is expected to take
about 4 months. As with the Tukwila Trunk, heavy
trucks will haul excavated material (3,500 cubic
yards) from the pipeline alignment and haul bedding
and fill material (3,500 cubic yards), pipe and
ancillary equipment to the construction sites.
This will generate a daily average of about 12 one -
way trips over the course of construction.
As with the Tukwila Trunk, construction workers are
expected to number from 6 to 12 at any given time.
Construction workers are expected to drive private
vehicles to the project site, generating an
additional 12 to 24 one -way trips each day.
Along the construction corridor, designated parking
areas for construction worker vehicles will be
established in order to minimize congestion and
parking problems for local business establishments
and recreational facilities (i.e. Foster Golf
Links, Fort Dent Park). During construction
through the golf course, workers will be required
to park vehicles in designated parking areas near
the new pumping station. During construction in
Fort Dent Park, a portion of the existing parking
facilities will be designated for construction
worker use.
Construction of the new forcemain will slightly
increase traffic volumes on Interurban Avenue S.,
the Fort Dent Park access road, I -5, Monster Road
S.W. and, if Forcemain Alternative A is selected,
Beacon Coal Mine Road, 68th Avenue S., Oakesdale
Avenue S.W. and S.W. Grady Way. Construction is
expected to occur during typical daytime working
hours. Nighttime or weekend work is not
anticpated.
The new forcemain will cross Monster Road S.W. and
enter the Metro treatment plant at Renton near the
main entrance gate. There is some potential for
traffic disruption in this area during construction
because of the vehicles entering and leaving the
plant during daytime hours. The forcemain will be
installed in the area using open cut methods. It
55
56
is expected that the forcemain can be installed
across Monster Road S.W. and the treatment plant
entrance road in a period of several days. Traffic
controls will be implemented to ensure that access
to the plant is maintained at all times and that
any disruption of traffic is kept to a minimum.
There is some potential for cumulative traffic
impacts at Metro's treatment plant at Renton if
construction schedules for the Interurban project
and proposed treatment plant improvements coincide.
(Refer to Draft Supplemental Environmental Impact
Statement: Metro Treatment Plant at Renton. Phase
III Enlargement (Metro, 1991) for a detailed
discussion of traffic impacts associated with the
plant expansion.)
g. Describe proposed measures to reduce or control
transportation impacts, if any.
Mitigation measures intended to reduce
transportation impacts include the following:
- minimizing delivery or removal of materials
during peak traffic hours;
- using flaggers to direct traffic at
construction sites as necessary;
- locating worker parking within the
construction zone or in specially- designated
areas;
- maintaining access to businesses and
recreational facilities at all times;
- minimizing the width of the construction
zone;
- mimimizing open trench lengths and the
amount of time trenches are left open;
- jacking the pipeline under I -5 and under
rail lines in order to avoid disruption of
surface and rail traffic;
- locating jacking pits outside access ramps
to and from I -5 in order to minmize congestion
at these locations; and
15'. Public Services
16. Utilities
- establishing a designated haul route within
Fort Dent Park to minimize potential conflicts
with park users.
a. Would the project result in an increased need for
public services (for example: fire protection,
police protection, health care, schools, other)?
If so, generally explain.
Implementation of this project will not increase
the need for public services. The project will
improve sanitary sewer service in the City of
Tukwila and will result in the more efficient
conveyance of flows from the Val Vue Sewer District
to the Metro system. The frequency of overflows to
the Duwamish River is expected to decrease as the
capacity of the Tukwila Trunk is increased.
b. Describe proposed measures to reduce or control
direct impacts on public services.
Measures to reduce or control impacts on public
services will not be necessary.
a. Circle utilities currently available at the site:
Electricity, natural gas, water, refuse service,
telephone, sanitary sewer, septic systems, other
All of the above underlined utilities are available
in the vicinity of the pumping station and
forcemain alternatives.
b. Describe the utilities that are proposed for the
project, the utility providing the service, and the
general construction activities on the site or in
the immediate vicinity which might be needed.
The new Interurban Pumping Station will utilize
electrical energy to convey wastewater through the
forcemain to the Metro treatment plant at Renton.
An uninterruptible power supply will be provided to
maintain power to pumping station instrumentation
and controls. Puget Sound Power and Light Company
will provide electrical service.
The pumping station will also be equipped with
exterior electrical service plug receptacle to
57
C. SIGNATURE
Date Submitted: dlln
allow connection to a portable electrical
generator. A second backup power source may be
provided. Water, sewer, and telephone services
will also be provided at the new pumping station.
Electrical power will also be required to power the
odor control unit located at the new pipebridge
crossings at the Black River (Forcemain Alternative
A) and at the south end of Fort Dent Park
(Forcemain Alternative B).
The above answers are true and complete to the best of my
knowledge. I understand that the lead agency is relying on
them to make its decision.
Signature: C. je
58
REFERENCES
Golder Associates, Inc. "Preliminary Geotechnical Study: Tukwila
Trunk Sewer Rehabilitation Project, Tukwila, Washington."
Prepared for Municipality of Metropolitan Seattle. July 1990.
Municipality of Metropolitan Seattle, Environmental Analysis - Task
390, Alki Transfer - CSO Control Facilities Pro Seattle,
Washington. 1990.
Municipality of Metropolitan Seattle, Final Plan for Secondary
Treatment Facilities - Volume II, Plan for Secondary Treatment
Facilities and Combined Sewer Overflow Control, Seattle,
Washington, 1985.
Municipality of Metropolitan Seattle, Facilities Plan
Transfer - CSO Control Facilities Project,
Washington, 1990.
City
City
City
City
59
for Alki
Seattle,
Municipality of Metropolitan Seattle, Predesign Report
Transfer - CSO Control Facilities Project,
Washington, 1990.
for Alki
Seattle,
Municipality of Metropolitan Seattle, Draft Supplemental
Environmental Impact Statement: Metro Treatment Plant at
Renton - Phase III Enlargement, Seattle, Washington, 1991.
of Renton. City of Renton: Comprehensive Plan (Compendium).
Policy Development Department, Renton, Washington. March 1986.
of Renton. "Land Clearing and Tree Cutting Ordinance."
Ordinance No. 4219, Renton, Washington. June 1989.
of Renton . Shoreline Master Proctram: City of Renton.
Ordinance No. 3758 as amended. Renton, Washington. December
1983.
of Renton Planning Department and Northwest Environmental
Consultants, Inc. City of Renton Wetlands Study: A
Reconnaissance Study of Selected Wetlands in the City of
Renton. Renton, Washington. February 1981. 24 p.
Shapiro and Associates, Inc. "Wetland Delineation of the Container
Corporation of America Site, Renton, Washington," Prepared for
Bruce Blume and Company, Seattle, Washington. June 1989. 26 p.
City of Tukwila. City of Tukwila: Water Resource Rating and Buffer
Recommendations. Prepared by Jones and Stokes, Associates,
Inc., Tukwila, Washington. May 1990.
.,
City of Tukwila. City of Tukwila: Shoreline Master Plan. Prepared
for City of Tukwila Planning Department by Jones & Jones,
Consultants. Ordinance #898 as amended. Tukwila, Washington.
June 1974.
City of Tukwila. The Tukwila Zoning Code. City of Tukwila Planning
Department, Tukwila, Washington. Undated.
City of Tukwila. City of Tukwila: Comprehensive Land Use Policy
Plan. Planning Division, Department of Community Development.
Ordinance #1246. Tukwila, Washington. March 1982.
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