Loading...
HomeMy WebLinkAbout2016-01 - SEPA Checklist - BNSF Intermodal Facility AccessSEPA Checklist Tukwila BNSF Intermodal Facility Access Project City of Tukwila, Washington Applicant: CITY OF TUKWILA Bob Giberson, Public Works Director 6300 Southcenter Boulevard Tukwila, WA 98188 Prepared by: DAVID EVANS AND ASSOCIATES, INC. 14432 SE Eastgate Way, Suite 400 Bellevue, WA 98007 December 2016 RECEIVED JAN 05 2017 coMro11NI ry ULVLLUI 'MLNT CITY OF TUKWILA Department of Community Development 6300 Southcenter Boulevard, Ste 100 Tukwila, WA 98188 Telephone: (206) 431-3670 SEPA ENVIRONMENTAL REVIEW INFORMATION The State Environmental Policy Act (SEPA) requires all agencies to consider the environmental impacts of a development before making decisions (43.21C RCW). The purpose of environmental review is to identify a proposal's significant adverse impacts, measures to minimize or avoid such impacts, and allow wide public review for a wide range of projects. REQUIREMENTS: SEPA review is required for any action associated with the following types of decisions: 1. Developing 10 or more dwelling units. 2. Developing agricultural structures over 10,000 s.f. 3. Developing office, school, commercial, recreational, service or storage buildings over 12,000 s.f. and 40 parking spaces (certain utility lines, personal wireless communication facilities, and normal maintenance/replacement activities are fully exempt). 4. Developing parking lots with over 40 spaces. 5. Landfills and excavations over 500 cubic yards. 6. Installation of impervious underground tanks with a capacity over 10,000 gallons. The accompanying application must be completed for any new SEPA application or request to issue an addendum to any previous SEPA determination. If a question does not apply, "Does not apply" or "NA" may be entered. Complete answers to the checklist may avoid unnecessary delays later. City staff may also be able to help about governmental designations (e.g., zoning, shoreline, and landmark status). PROCEDURES: At the time you submit your application you must have all of the items listed on the attached "Complete Application Checklist" as well as the submittal for the underlying action (building permit, subdivision etc.). You may request a waiver from items on the checklist that are not applicable to your project. Please discuss this waiver request with City staff either at a pre -application meeting or at the time of application submittal. Within 28 days of receiving your application, City staff will determine if it is complete based on the attached checklist. If not complete City staff will mail to you a letter outlining what additional information is needed. If you do not submit requested materials within 90 days from the City's request for additional information the City may cancel your application. Once the application is "complete," substantive review will begin and a "Notice of Application" must be posted/mailed to begin a public comment period. After completing the environmental analysis and considering public comments, the Director will issue a determination for the project. A Determination of Non -Significance (DNS) says that the project as proposed will not have probable, significant, negative environmental impacts. A mitigated DNS will be issued if the project must be modified to mitigate its negative impacts. An Environmental Impact Statement (EIS) must be prepared if the probable negative impacts are unavoidable. JAN 05 2017 t r,rot..1itillY ULVLL01 'AIL( r UcitystnrelCity CommonlTen - DCDVKtrby\SEPA to fix1SEPA Environmental Review Application FINAL 5-9-I6.docx COMPLETE APPLICATION CHECKLIST The materials listed below must be submitted with your application unless specifically waived in writing by the Public Works Department and the Department of Community Development. Please contact each Department if you feel that certain items are not applicable to your project and should be waived. Application review will not begin until it is determined to be complete. ADDITIONAL MATERIALS MAY BE REQUIRED. The initial application materials allow project review to begin and vest the applicant's rights. However, the City may require additional information as needed to establish consistency with development standards. City staff are available to answer questions about application materials at 206-431-3670 (Department of Community Development) and 206-433-0179 (Department of Public Works). Check items submitted with application Information Required. May be waived in unusual cases. upon approval of both Public Works and Planning APPLICATION MATERIALS: 1 1. Application Checklist (1 copy) indicating items submitted with application. i.._- ./ 2. Completed ESA Screening Checklist, SEPA Environmental Checklist and drawings (5 copies). i 3. One set of all plans reduced to 8 1/2" x 11" or 11" x 17". 4. Application Fee: See Land Use Fee Schedule. 5. Underlyinapermit application that triggers SEPA review. iJ 9� P4 y 5" 9 S "/ o0 PUBLIC— NOTICE MATERIALS: 9 9g /o4v? . rmov - oy ✓ 6. Payment of notice board fee (see Land Use Fee Schedule) to FastSigns OR provide a 4' x 4' public notice board on site within 14 days of the Department determining that a complete application has been received (see Public Notice Sign Specifications I landoul). ✓ 7. Pay the fee as established by the Land Use Fee Schedule for generating mailing labels; OR provide an excel spreadsheet of mailing labels for all property owners and tenants (residents and businesses) within 500 feet of the subject property. Each unit in multiple family buildings e.g. apartments, condos, trailer parks --must be included. Once your project is assigned to a planner, you will be required to provide an electronic copy of the mailing label spreadsheet in the following format: Name, Street Address, City St Zip, with each of these fields as an individual column: Name Street Address City, St, Zip Mr. Smith 1234 Park Ave S Tukwila WA 98188 PLEASE NOTE: Regardless of whether you pay the City to generate the mailing labels or you provide them, there is an additional fee for postage and material as listed under Public Notice Mailing Fee on �e Land Use Fee Schedule. Payment of this fee is due prior to issuance of the decision and you will receive a separate bill for this fee. ✓ 8. If providing own labels, include King County Assessor's map(s) which shows the location of each property within 500 ft. of the subject lot. • •citystore•City Common'.Ten - DCDIKirby'.SEPA to fix.SEPA Emtronmental Review Application FINAL 5-9-16 docx Check items submitted with application Information Required. May be waived in unusual cases, upon approval of both Public Works and Planning PROJECT DESCRIPTION AND ANALYSIS: 9. Vicinity Map with site location. ✓ 10. Provide four (4) copies of any sensitive area studies such as wetland or geotechnical reports if needed per Tukwila's Sensitive Areas Ordinance (TMC 18.45). See the Geotechnical Report Guidelines and Sensitive Area Special Study Guidelines for additional information. ✓ 11. Any drawings needed to describe the proposal other than those submitted with the underlying permit. Maximum size 24" x 36". \\citystore\City Common\Teri - DCD\Kirby\SEPA to fix\SEPA Environmental Review Application FINAL 5-9-16 docx CITY OF TUKWILA Department of Community Development 6300 Southcenter Boulevard, Ste 100 Tukwila, WA 98188 Telephone: (206) 431-3670 SEPA ENVIRONMENTAL REVIEW APPLICATION FOR STAFF USE ONLY Permits Plus TYPE: P-SEPA Planner: File Number: �i \)-00 C I Application Complete Date: Project File Number: pj-- V -1—0 0 d -1—- Application Incomplete Date: Other File Numbers: NAME OF PROJECT/DEVELOPMENT: BNSF Intermodal Facility Access Project BRIEF DESCRIPTION OF SCOPE OF WORK: Improve truck access to BNSF Intermodal Facility and remove intermodal trucks from residential neighborhoods. This application requires public notice. Please see section 7 of the application checklist. LOCATION OF PROJECT/DEVELOPMENT: Give street address or, if vacant, indicate lot(s), block and subdivision, access street, and nearest intersection. 48th Avenue South (Interurban Avenue South to Duwamish River) see attachments LIST ALL TAX LOT NUMBERS (this information may be found on your tax statement). none (right-of-way improvement project) DEVELOPMENT COORDINATOR/ PROJECT CONTACT: The individual who: • has decision making authority on behalf of the owner/applicant in meetings with City staff, • has full responsibility for identifying and satisfying all relevant and sometimes overlapping development standards, and _ • is the primary contact with the City to whom all notices and reports will be sent. E C it rn • PLEASE PRINT CLEARLY Name: Bob Giberson, Public Works Director Address: 6200 Southcenter Boulevard JAN052011 t:r)M1',t itjII' Di VI El ll't4l-l-i CITY, ST, ZIP Tukwila WA, 98188 E-mail: publicworks@tukwilawa.gov Phone: 206) 433-0179 Signature: Date: l 2 - 2 - / 6 \LcitystorelCity CommonlTeri - DCD1KirbyISEPA to Gx\SEPA Environmental Review Application FINAL 5-9-16.docx STATE OF WASHINGTON COUNTY OF KING The CITY OF TUKWILA Department of Community Development 6300 Southcenter Boulevard, Ste 100, Tukwila, WA 98188 Telephone: (206) 431-3670 AFFIDAVIT OF OWNERSHIP AND HOLD HARMLESS PERMISSION TO ENTER PROPERTY (RIIT-O--WI) iBtr6 ersigned being duly sworn and upon oath states as follows: 1. I am he current owner of the property which is the subject of this application. 2. All sta ments contained in the applications have been prepared by me or my agents and are true and correct to the best of my knowle• e. 3. The applic ion is being submitted with my knowledge and consent. 4. Owner grants • e City, its employees, agents, engineers, contractors or other representatives the right to enter upon Owner's real property, locate = t for the purpose of application review, for the limi -d time necessary to complete that purpose. 5. Owner agrees to hold t City harmless for any loss or damage to persons or property occurring on the private property during the City's entry upon the roperty, unless the loss or damage is the result of the sole negligence of the City. 6. Non -responsiveness to a Cit ' information request for ninety (90) or more days, shall be cause to cancel the application(s) without refund of fees. EXECUTED at (city), (state), on , 20 (Print Name) (Address) (Phone Number) (S : nature) On this day personally appeared before me to me known to be the individual who executed the foregoing instrument and acknowledged that he/she signed th- . ame as his/her voluntary act and deed for the uses and purposes mentioned therein. SUBSCRIBED AND SWORN TO BEFORE ME ON THIS DAY O , 20 NOTARY PUBLIC in and for the tate of Washington residing at My Commission expires on \\citystore\City ComtnonlTeri - DCLAKirby\SEPA to f x SEPA Environmental Review Application FINAL 5-9-16.docx City of Tukwila Endangered Species Act Screening Checklist Date: December 6, 2016 Applicant Name: City of Tukwila Public Works Department Street Address: 6300 Southcenter Boulevard City, State, Zip: Tukwila, WA 98188 Telephone: (206) 433-0179 DIRECTIONS: This Screening Checklist has been designed to evaluate the potential for your project to result in adverse effects to salmonids - Chinook, Coho, Cutthroat trout or char - as defined by Section 9 of the Endangered Species Act (ESA). If potential effects are identified, the project may need further evaluation. Please review and answer each question carefully. Consider all phases of your project including, but not limited to, construction, normal operation, potential emergency operation, and ongoing and scheduled maintenance. To answer these questions, you may need to refer to site plans, grading and drainage plans, critical areas studies, or other documents you have prepared for your project. The City will evaluate your responses to determine if additional action is indicated. W:\APPLICATIONS - Land Use Apps & Handouts\CURRENT LAND USE APPLICATIONS\SEPA Environmental Review Application FINAL 5-9-16 doc If ESA listed species are present or ever were present in the watershed where your project will be located, your project has the potential to affect them, and you need to comply with the ESA. The questions in this section will help determine if the ESA listings will impact your project. For more information on potential salmonid presence in your project area contact the Washington Department of Fish and Wildlife Habitat Biologist for your region, Washington Department of Fish and Wildlife or use the SalmonScape tool, WNW SalmonScape. 1. Are ESA listed salmonids currently present in the watershed within which your project will be located? YesEl No0 Please describe. The project is located within the Duwamish/Green Water Resource Inventory Area (WRIA). Fish in the Duwamish River include several species listed as threatened under ESA, including Chinook salmon, steelhead trout, and bull trout. These species use the portion of the river in the project area as migration habitat to and from marine waters and upstream spawning and rearing areas higher in the watershed. This portion of the Duwamish River is also designated critical habitat for bull trout and Chinook salmon. 2. Has there ever been an ESA listed salmonid stock present in this watershed? YestyNo❑ Uncertainty Please describe. See previous answer. If you answered "yes" to either of the above questions you should complete the remainder of this checklist. W:\APPLICATIONS - Land Use Apps & Handouts\CURRENT LAND USE APPLICATIONS\SEPA Environmental Review Application FINAL 5-9-16 doc City of Tukwila ESA Screening Checklist Part A - PROJECT SPECIFICS: Project and Vicinity 1. Name of watershed: Duwamish/Green 2. Name of nearest water body: Duwamish River 3. What is the distance from this project to the nearest body of water? 0 ft' 4. What is the current land use between the project and the potentially affected water body (parking lots, farmland, etc)? Commercial and light industrial buildings, parking lot, river bank, recreational trail, industrial railyard 5. Is the project above a: • Natural permanent barrier (waterfall) Yes Noj • Natural temporary barrier (beaver pond) Yesn Non✓ • Man-made barrier (culvert, dam) YesQ NoEl • Other (explain): The project will include a bridge over the Duwamish River for trucks accessing the BNSF railyard. It does not include a fish barrier. 6. If answered Yes in #5, are there any resident salmonid populations above the blockage? Yesf l NoEL Don't known Not applicable. \\citystore\City Common\Teri - DCD\Kirby\SEPA to 6x\SEPA Environmental Review Application FINAL 5-9-I6.docx W:\APPLICATIONS - Land Use Apps & Handouts\CURRENT LAND USE APPLICATIONS'SEPA Environmental Review Application FINAL 5-9-16.doc City of Tukwila ESA Screening Checklist Part B - Project Specifics: Grading and Land Alteration 1. Does the project involve grading or land alteration of any kind? Yes Fi No n If your project DOES NOT involve grading please skip to Part C. 2. Will the project involve the modification of a watercourse bank between Ordinary High Water (OHW) and the top of the bank? If yes, which water course? This includes any rading on any slope leading to a river or stream, but does not require work below OlIW. Yes 0 No Proposed bridge abutments will modify the banks of the Duwamish River above the OHWM. 3. Will the project involve the modification of a watercourse bank or bottom below OHW? If yes, please explain. Yes=l_No n 4. Could the construction, operation, or maintenance of equipment for the project result in sediment transport off site or increased rates of erosion and/or sedimentation in watercourses? If no, please explain. Most projects involving grading have the potential to result in increased erosion and/or sedimentation as a result of land disturbance. Yes 0 Noll 5. If the project involves grading, have you prepared a Temporary Erosion and Sedimentation Control Plan? Yes 0 No n If no, are you exempt under TMC 16.54.90? Yes n No 0 6. Will the project result in new impervious services? Include all hard surface are such as rooftops, asphalt or concrete pavin , compacted surfaces, etc. Yes 0 No 7. What percent of the project will be impervious surface (including pavement & roof area)? 90 to 100 percent of the project area will be impervious, after construction. W:\APPLICATIONS - Land Use Apps & Handouts\CURRENT LAND USE APPLICATIONS\SEPA Environmental Review Application FINAL 5-9-16 doc City of Tukwila ESA Screening Checklist Part C — Project Specifics: Water Quality 1. Will the project generate stormwater from the creation of impervious surfaces that will not be infiltrated on site? Please explain. For the purpose of this analysis, infiltration includes the use of a stormwater treatment and management system intended to contain all stormwater on site by allowing it to seep into the ground. Yes No n Project will result in additional stormwater runoff that will receive treatment, but not necessarily infiltration. 2. Will the project result in the processing or handling, storage, or treatment of hazardous substances? This does not include fuel properly stored in a vehicle fuel tank, but does include fuel or other chemicals stored on -site during construction. Yes 0 No n On -site hazardous substances could include paint or stored fuel. 3. Will the project require long-term or re -occurring maintenance requiring the use of fertilizers, pesticides, or other chemicals? This may include landscape maintenance, bridge or parking lot cleaning, ice removal/melt, repeated chemical vegetation clearing, etc. Yes No n Recurring maintenance could include the use of fertilizers or pesticides. 4. Will turbidity be increased during construction or operation of the project? Please explain any measures to be taken to ensure turbidity is not increased. Construction near the water or below OHW often will increase turbidity, both on -site and downstream. Yes 7 No n During construction, standard BMPs) will be employed in order to minimize erosion potential. BMPs could include but not be limited to silt fences, straw wattles, inlet protection, and hydroseed. 5. Will the project either reduce or increase shade along or over a water body? Removal of trees/vegetation or the building of over -water structures (docks or floats) will often result in a change to shade. Yes 0 No n The bridge over the Duwamish River will increase the amount of shade over the river. 6. Will the project require debris removal from below OHW of a water course? Debris includes, but is not limited to, fallen trees, logs, shrubs, rocks, piles, riprap, submerged metal, broken concrete, pipes, or other construction material. Yes n No FA W:\APPLICATIONS - Land Use Apps & Handouts\CURRENT LAND USE APPLICATIONS\SEPA Environmental Review Application FINAL 5-9-16 doc City of Tukwila ESA Screening Checklist Part D — Project Specifics: Flow Alterations and Fish Migration 1. Will the project involve the direct alteration of the channel or bed of a water course? This includes both tempolEy and ermanent modifications. If yes, please explain. Yes I No I✓ 2. Will the project involve any physical alteration to a wetland which is connected to a water course? Few Wigligncis are isolated most contain either surface or subsurface connection to allowing water course. Yes No fl 3. Will water be rerouted, either temporarily or permanently as a result of the project? If yes, please explain. Yes n No 0 4. Will a culvert be installed or removed as part of this project? Yes n No 5. Will the project require withdrawal of surface water? If yes, please include amount and name or water body. Yes n No Fi 6. Will the project result in the withdrawal, injection, or interception or groundwater? Examples of projects that might affect groundwater include, but are not limited to, construction of a new well, changes in withdrawal from an existing well, projects involving prolonged dewalering, installation of French drains, swales, or sewer lines. Projects that require a geoteclmical report ur srrant to T rl /C 18. 45.060 should answer Yes. Yes n No I I Additional stormwater runoff will occur from additional Impervious surface. The existing closed stormwater detention . . system will be reconstructed; a storage/water quality vault may be constructed. Stormwater runoff will be managed it' accordance with the Ecology 2012 Stormwater Management Manual for Western Washington. 7. Will topography changes on the site affect the duration/direction of surface runoff flows? If yes, please describe chan es.. Yes�No 111 8. Will the project include bank stabilization? If yes, explain. Bank stabilization includes, but is not limited to, riprap, rock, logs, soil, vegetated revetments, concrete structures, or similar. Yes 0 No n Project will include stabilization and scour protection around new bridge abutments on bank of Duwamish River. 9. Will there be retention or detention ponds? If yes, will this be an infiltration pond or a surface discharge to either a municipal storm water system or a surface water body? Yes_QNon✓ 10. Will the project involve any reduction of the floodplain or floodway by filling or other partial blockage of flows? If yes, how will the loss of flood storage be mitigated by your project? Yes n Non 11. Will project include the construction of a new wetland or waterway that is connected by surface flow to an existing waterway that contains salmonids? Yes (l Non✓ W:\APPLICATIONS - Land Use Apps & Handouts\CURRENT LAND USE APPLICATIONS\SEPA Environmental Review Application FINAL 5-9-I6 doc SEPA ENVIRONMENTAL CHECKLIST Purpose of checklist: Governmental agencies use this checklist to help determine whether the environmental impacts of your proposal are significant. This information is also helpful to determine if available avoidance, minimization or compensatory mitigation measures will address the probable significant impacts or if an environmental impact statement will be prepared to further analyze the proposal. Instructions for applicants: This environmental checklist asks you to describe some basic information about your proposal. Please answer each question accurately and carefully, to the best of your knowledge. You may need to consult with an agency specialist or private consultant for some questions. You may use "not applicable" or "does not apply" only when you can explain why it does not apply and not when the answer is unknown. You may also attach or incorporate by reference additional studies reports. Complete and accurate answers to these questions often avoid delays with the SEPA process as well as later in the decision -making process. The checklist questions apply to all parts of your proposal, even if you plan to do them over a period of time or on different parcels of land. Attach any additional information that will help describe your proposal or its environmental effects. The agency to which you submit this checklist may ask you to explain your answers or provide additional information reasonably related to determining if there may be significant adverse impact. Instructions for Lead Agencies: Please adjust the format of this template as needed. Additional information may be necessary to evaluate the existing environment, all interrelated aspects of the proposal and an analysis of adverse impacts. The checklist is considered the first but not necessarily the only source of information needed to make an adequate threshold determination. Once a threshold determination is made, the lead agency is responsible for the completeness and accuracy of the checklist and other supporting documents. Use of checklist for nonproject proposals: For nonproject proposals (such as ordinances, regulations, plans and programs), complete the applicable parts of sections A and B plus the SUPPLEMENTAL SHEET FOR NONPROJECT ACTIONS (part D). Please completely answer all questions that apply and note that the words "project," "applicant," and "property or site" should be read as "proposal," "proponent," and "affected geographic area," respectively. The lead agency may exclude (for non -projects) questions in Part B - Environmental Elements —that do not contribute meaningfully to the analysis of the proposal. A. BACKGROUND 1. Name of proposed project, if applicable: BNSF Intermodal Facility Access Project 2. Name of applicant: City of Tukwila Public Works SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 3 of 23 3. Date checklist prepared: December 29, 2016 5. Agency requesting checklist: City of Tukwila 6. Proposed timing or schedule (including phasing, if applicable): Complete the study phase in 2017, pursuit grant funding for final design and expanded permitting in 2018 and 2019. The design, right-of-way and detailed environmental documentation phases are expected to be completed by 2021 and construction phase is expected to last approximately 12 months and occur between 2022 and 2023, depending on timing of each previous phase. 7. List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal. • Alternative Screening Analysis Report • Existing Conditions Report • Cultural Resources Assessment • Alternatives Analysis Hazardous Materials Review • Geotechnical Engineering Services Report 8. Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by your proposal? If yes, explain. No applications for governmental approvals of other proposals directly affecting the proposed project property are known to exist. 9. List any government approvals or permits that will be needed for your proposal, if known. After the final design and full environmental documentation phases are fully funded, work will begion on: National Environmental Policy Act compliance Section 10 of the Rivers and Harbors Act Permit (US Army Corps of Engineers) US Coast Guard Bridge Permit Section 4(f) Temporary Occupancy approval City of Tukwila Critical Areas Regulations compliance Hydraulic Project Approval (Washington Department of Fish and Wildlife) City of Tukwila Shoreline Management Act permit Coastal Zone Management Certification National Pollutant Discharge Elimination System (NPDES) Baseline General Construction Permit One or more of the following local permits may be required by the City of Tukwila: • Grading • Right-of-way Use • Road Improvement • Storm Drainage • Sanitary Sewer SEPA Environmental checklist (WAC 197-11.960) Form Updated May 2014 Page 4 of 23 10. Give brief, complete description of your proposal, including the proposed uses and the size of the ( project and site. There are several questions later in this checklist that ask you to describe certain aspects of your proposal. You do not need to repeat those answers on this page. (Lead agencies may modify this form to include additional specific information on project description.) The project will improve access to the Burlington Northern Santa Fe Railway (BNSF) South Seattle Intermodal Facility (BNSF railyard) and improve traffic flow through the surrounding neighborhoods. It will involve relocating the BNSF railyard truck access route from S 124th Street to 48th Avenue S. Project components include improving existing 48th Avenue 5 starting at Interurban Avenue 5 and extending 48th Avenue 5 to the BNSF railyard to the east and north. The extension would require a bridge over the Green River Trail, a bridge over the Duwamish River, an at -grade intersection with S 130th PI (Railroad Avenue), and a route under the S 129th Street overpass. The new road will provide access to a new truck -queuing area located on the existing paved area between 51st Place S and the forested strip west of the trailer parking area. New lanes would be striped in this area to allow for two lanes entering and three lanes exiting the truck -queuing area. Trucks will exit the queue at the west end and will be processed through the check -in facility. The area to be improved covers approximately 5.5 acres. The project would include road improvements at the intersection of Interurban Avenue S and 48th Avenue 5, including rebuilding and resignalizing the intersection. Improvements on 48th Avenue S will include either placing a new asphalt overlay on the existing road section; or (1) demolishing the roadway section, (2) establishing subgrade, and (3) constructing a new roadway section. The roadway profile would be raised starting approximately 375 feet west of the Green River Trail to meet the elevation of the proposed bridge. During construction, access to businesses would be maintained. No vehicle detours would be necessary, although temporary and intermittent one -lane closures on 48th Avenue S and S 130th PI (Railroad Avenue) will occur. The proposed single -span concrete girder bridge will be approximately 175 feet long and 40 feet wide, oriented approximately east -west with two travel lanes and one 10-foot sidewalk on the north side, and will extend from approximately 100 feet west of the Green River Trail to Railroad Avenue. The west bridge abutment will be located between the river and the Green River Trail. The intersection of Railroad Avenue and 48th Avenue S and portions of Railroad Avenue near this intersection would be reconstructed to match the grade of the north approach to the bridge. The north bridge abutment will be located between the river and Railroad Avenue. Railroad Avenue is currently a two-way road paved with asphalt concrete oriented along the east river bank adjacent to the crest of the slope. Concrete jersey barriers separate Railroad Avenue from the slope. Staging and storage will occur along 48th Avenue 5 and at either end of the proposed bridge. Any unpaved area used for construction staging or storage would be restored to its existing condition, including any disturbed area near the river. 11. Location of the proposal. Give sufficient information for a person to understand the precise location of your proposed project, including a street address, if any, and section, township, and range, if known. If a proposal would occur over a range of area, provide the range or boundaries of the site(s). Provide a legal description, site plan, vicinity map, and topographic map, if reasonably available. While you should submit any plans required by the agency, you are not required to duplicate maps or detailed plans submitted with any permit applications related to this checklist. SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 5 of 23 The BNSF railyard is located between the community of Allentown, within the City of Tukwila, and Interstate 5, bounded approximately by the S Boeing Access Road at the north and Interstate 5 at the south. The proposed new route will begin at Interurban Avenue S, which trucks will access from either Interstate 5 or SR 599. Trucks will proceed northeast from Interurban Avenue S along 48th Avenue S. The route will cross over the Green River Trail and the Duwamish River, join S 130th PI (Railroad Avenue) at -grade, and travel underneath S 129th Street. The project is located in Sections 11, 14, and 15 of Township 23 North and Range 04 East, Willamette Meridian. Attachment A, This Alternative Screening Analysis Report for the City of Tukwila was prepared by David Evans and Associates, Inc. to evaluate alternative access to the BNSF Railway intermodal facility in Tukwila. The existing access to the intermodal facility uses 42nd Avenue S and S 124th Street. S 124th Street is also a residential collector street serving the community of Allentown. Several residential homes with driveways are located on S 124th Street, as is the Tukwila Community Center which houses an aquatic center, meeting rooms, classes and activities for all ages, and playground and ball fields. This study did not create new alternatives but used alternatives that were developed by previous studies. A total of five alternatives were studied: Airport Way S, 5 112th Street, S 124th Street, Gateway Drive — North Leg, and 48th Avenue S. Several desktop researches were performed as part of this study. These researches included critical and sensitive areas, fish and wildlife, water resources, hazardous materials, geological and soils, and cultural and historical resources. A scored screening matrix was developed collaboratively between the City of Tukwila, BNSF Railway, and David Evans and Associates, Inc. The matrix was presented to Tukwila City Council as well as to the public for their feedback on the screening matrix criteria. The public was allowed to provide feedback via an on- line open house and an in -person open house. Representatives from Tukwila, BNSF Railway, and David Evans and Associates, Inc. met to score each alternative using a numerical scoring system from 1 to 9. The score for each criteria was added, and the lowest score is the preferred alternative. Based on the scoring result, the 48th Avenue 5 alternative is the preferred alternative and is the focus of this SEPA proposal. 12. Does the proposal lie within an area designated on the City's Comprehensive Land Use Policy Plan Map as environmentally sensitive? Yes, see Attachment E and NW Maps sensitive area maps for all alternatives studied. B. ENVIRONMENTAL ELEMENTS 1. Earth a. General description of the site: (circle one): Flat, rolling, hilly, steep slopes, mountainous, other SEPA Environmental checklist (WAC 197-11.960) Form Updated May 2014 Page 6 of 23 The proposed road would be improved and extended through a relatively flat, currently -developed area. b. What is the steepest slope on the site (approximate percent slope)? The steepest slope on the project site is likely less than 5 percent, not including the banks of the Duwamish River, which the City of Tukwila identifies as Slope Classifications 2 and 3. The south river bank slope appears to be at a gradient between 1H to 1V and 2H to 1V, where H is the cut -back distance and V is the depth. The north river bank appears to be over -steepened and may be undercut below the waterline. An area southeast of Codiga Park, between the park and the river, has slopes between 15 and 40 percent. This area is near where the road would extend toward the truck queuing area. c. What general types of soils are found on the site (for example, clay, sand, gravel, peat, muck)? If you know the classification of agricultural soils, specify them and note any agricultural land of long-term commercial significance and whether the proposal results in removing any of these soils. Predominant geologic units mapped in the area of the proposed project include alluvium, bedrock, and glacial deposits. Alluvial deposits are mapped in the lowland areas around the Duwamish River. The project is primarily located within the areas mapped as alluvial deposits. Bedrock is mapped along the southeastern edge of the Duwamish River valley in the project area. Glacial deposits are mapped along the southwestern edge of the project area. Based on the Site Class Map of King County, Washington, the majority of the alluvial soils in the vicinity of the project are mapped as Site Class D to E. Bedrock outcrops are mapped as Site Class B. Soils near the intersection of 48th Avenue South and Interurban Avenue generally consist of medium dense sand and silty sand and stiff clayey silt, which is consistent with the mapped geology along the alignment and the general description of alluvium in their report. Soils described in the reviewed logs north of the railyard tracks adjacent to the slope that forms the edge of the Duwamish River valley consisted of alluvial soils overlying bedrock. The bedrock was described as partially fractured and moderately to highly weathered. The depth to bedrock varied in the exploration logs; however, in the one exploration log located near the existing tracks (similar surface elevation to the area of the proposed bridge), bedrock was encountered at about 20 feet below ground surface. The depth to bedrock will likely vary in the area of the project and in general, will be deeper as work moves farther away from mapped bedrock locations and the valley walls. See Attachment B, Geotechnical Report for more information. d. Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe. GeoEngineers did not mention in their report any known surface indication or known history of unstable soils in the immediate vicinity of the project. The report does discuss erosional forces' effects, including rivers, on slopes and therefore on stability. See Attachment B, Geotechnical Report, for more information. e. Describe the purpose, type, total area, and approximate quantities and total affected area of any filling, excavation, and grading proposed. Indicate source of fill. SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 7 of 23 Excavation will occur (up to 3,000 cubic yards) and fill will be placed (up to 40,000 cubic yards) to construct the new roadway and to complete the truck -queuing area. The cut and fill areas would occur over an approximately 270,000-square-foot area. Fill, likely gravel borrow or a similar material, will be sourced locally from a City -approved facility. f. Could erosion occur as a result of clearing, construction, or use? If so, generally describe. According to the City of Tukwila Sensitive Areas Map, slopes steeper than approximately 15 degrees are mapped along the banks of the Duwamish River near the project area. The steep riverbank slopes have the potential for ongoing erosion and undercutting from river flow. These slopes will likely need to be modified or reinforced in order to improve stability if construction occurs near the slopes. During construction, standard Best Management Practices (BMPs) will be employed in order to minimize erosion potential. BMPs could include but not be limited to silt fences, straw wattles, inlet protection, and hydroseed. See Attachment B, Geotechnical Report, for more information. g. About what percent of the site will be covered with impervious surfaces after project construction (for example, asphalt or buildings)? Approximately 90 to 100 percent of the project area will be impervious surface after construction. Approximately 50 percent (135,000 square feet) of the project area is currently impervious surface. After construction, approximately 270,000 square feet of impervious surface will cover the project area. h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any: Based on the current condition of the riverbank slopes near the planned north and south bridge abutments, GeoEngineers anticipates that improvements to both river bank slopes will be necessary to construct the bridge (see also Part B [1] [f]). Flattening the slopes, installing cutoff sheet piles, constructing a bench in the slope, constructing a retaining wall, or installing large rock (riprap) or other engineered materials to the face of the slope may be necessary to improve the stability and reduce erosion potential. Re -graded slopes armored with large diameter rocks or riprap are typically economical and effective at stabilizing slopes and preventing erosion. The soils near the riverbank slopes are likely liquefiable and there is a risk of lateral spreading of the slopes towards the river during a seismic event. Lateral spreading could impact the bridge embankments and could place additional loads on the bridge foundations. The potential for lateral spreading will need to be evaluated at both the north and south slopes and, if necessary, lateral spreading hazards should be mitigated. Typically, lateral spreading and liquefaction settlement mitigation can be addressed together with either ground improvement, deep foundations, or a combination of both. See Attachment B, Geotechnical Report for more information. During construction, BMPs will be employed in accordance with the 2012 Washington State Department of Ecology (Ecology) Stormwater Management Manual. 2. Air a. What types of emissions to the air would result from the proposal during construction, operation, and maintenance when the project is completed? If any, generally describe and give approximate quantities if known. SEPA Environmental checklist (WAC 197-11.960) Form Updated May 2014 Page 8 of 23 The Seattle area is a maintenance area for CO, Ozone (1-hour), and PM10. Localized exhaust emissions from large industrial truck traffic would transfer from the existing route on 5 124th Avenue in Allentown to 48th Avenue S. During construction, construction vehicles and equipment would result in temporary adverse impacts to air quality. The City of Tukwila will initiate a studyof impacts due to noise, light and vibration in the Allentown area, to be completed in 2017. The Puget Sound Clean Air Agency is installing air quality monitoring stations in Allentown to monitor air quality due to rail, freight, air, and vehicle traffic. The proposed project will move high volumes of freight traffic away from the Allentown neighborhood, to the primarily industrial and commercial area near 48th Avenue S. Properties sensitive to air quality near the new route include the hotel on 48th Avenue S and the homes west of the railyard, between 51st Place S and 50th Place S. b. Are there any off -site sources of emissions or odor that may affect your proposal? If so, generally describe. Existing air quality in the project area is currently affected by nearby transportation and industrial uses such as the railroad, airport, industrial activities and production (including freight movement), and highways. These existing sources of potential air emissions or odors would not change with the project or affect the project's construction or operation, although a relatively high volume of freight traffic would be relocated from S 124th Avenue to 48th Avenue S with the project. c. Proposed measures to reduce or control emissions or other impacts to air, if any: Appropriate BMPs would be employed during construction to reduce and control air quality impacts, including the following: • using well -maintained equipment and vehicles and minimizing prolonged periods of vehicle idling; and • if dust emissions are noted during construction, areas of exposed soils could be sprayed with water or other dust suppressant. 3. Water a. Surface Water: 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, wetlands)? If yes, describe type and provide names. If appropriate, state what stream or river it flows into. The project area is located in the Puget Sound Lowlands, within the tidally -influenced Duwamish estuary ecosystem. The Duwamish River is part of the Green/Duwamish Water Resource Inventory Area (WRIA) 9. The Duwamish River runs through the middle of the project area and is designated by the City of Tukwila as having shorelines of statewide significance. Although City of Tukwila sensitive area maps do not indicate the presence of wetlands, a ditch along the edge of the BNSF railyard may need to be analyzed. The Washington Department of Natural Resources (WDNR) Forest Practices Application Review System (FPARS) identifies the Duwamish River as a Type 1 perennial stream and shoreline of the state. The City of Tukwila Shoreline Environments Map designates the Duwamish River shorelines in the project area as SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 9 of 23 Urban Conservancy Shoreline Environment. The City's Shoreline Master Program (SMP) jurisdiction extends 200 feet from the ordinary high water mark (OHWM) of each side of the Duwamish River. 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 project will require work over the Duwamish River and within the shoreline management area on both sides of the Duwamish River. 3) Estimate the amount of fill and dredge material that would 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 material. No material will be added to or removed from the Duwamish River or wetlands. 4) Will the proposal require surface water withdrawals or diversions? Give general description, purpose, and approximate quantities if known. The project will not require any surface water withdrawals or diversions. 5) Does the proposal lie within a 100-year floodplain? If so, note location on the site plan. The project does not overlap with the 100-year floodplain. The nearest floodplain area is located in Codiga Park west of 50th Place S, near the south end of the BNSF railyard. The Duwamish River is a designated floodway that is contained by revetments. 6) Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge. No intentional discharges of waste materials would occur during construction. b. Ground Water: 1) Will groundwater be withdrawn from a well for drinking water or other purposes? If so, give a general description of the well, proposed uses and approximate quantities withdrawn from the well. Will water be discharged to groundwater? Give general description, purpose, and approximate quantities if known. No groundwater will be withdrawn from a well. 2) Describe waste material that will be discharged into the ground from septic tanks or other sources, if any (for example: Domestic sewage; industrial, containing the following chemicals... ; agricultural; etc.). 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) are expected to serve. No waste material will be discharged to the ground. c. Water runoff (including stormwater): SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 10 of 23 1) Describe the source of runoff (including storm water) and method of collectionand disposal, if any (include quantities, if known). Where will this water flow? Will this water flow into other waters? If so, describe. Additional stormwater runoff will occur after project construction as a result of an increase in impervious surfaces, including the bridge and extension of 48th Avenue S. The existing closed stormwater detention system will be reconstructed as part of the project. A storage and water quality vault may need to be constructed to accommodate the project. Stormwater runoff will be managed in accordance with the 2016 King County Surface Water Design Manual . Also, BMPs will be employed in accordance with the same manual. 2) Could waste materials enter ground or surface waters? If so, generally describe. GeoEngineers expects groundwater to be relatively shallow in the area; they anticipate that groundwater elevation will be within a few feet of the elevation of water in the Duwamish River. Groundwater elevation is expected to fluctuate due to seasons, precipitation, and water levels in the river. Site class in the alluvial soils along this route alignment will likely be D or E. Liquefaction susceptibility of the alluvial soils along the route alignment is likely moderate to high. Waste materials are unlikely to inadvertently enter ground or surface waters, as a result of the proposed project. Construction stormwater will be collected and managed in accordance with the 2016 King County Surface Water Design Manual . 3) Does the proposal alter or otherwise affect drainage patterns in the vicinity of the site? If so, describe. The existing outfalls will remain the same. A Filterra or equivalent modular wetland system will be used; treated stormwater will be discharged into the Duwamish River. d. Proposed measures to reduce or control surface, ground, and runoff water, and drainage pattern impacts, if any: BMPs will be employed in accordance with the 2016 King County Surface Water Design Manual. 4. Plants a. Check the types of vegetation found on the site: _ X _deciduous tree: alder, maple, aspen, other _X_evergreen tree: fir, cedar, pine, other _X_ shrubs grass pasture crop or grain Orchards, vineyards or other permanent crops. wet soil plants: cattail, buttercup, bullrush, skunk cabbage, other water plants: water lily, eelgrass, milfoil, other other types of vegetation b. What kind and amount of vegetation will be removed or altered? SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 11 of 23 Up to 10 trees will be removed. Most trees that will require removal are landscaped street trees along 48th Avenue S, although at least two large bigleaf maples on the riverbank would likely need to be removed and one large cedar tree near the end of 48th Avenue S may require removal. c. List threatened and endangered species known to be on or near the site. No threatened or endangered plant species are known to be on or near the site. d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: After construction, disturbed areas would be restored with landscaping and trees, similar to existing conditions. e. List all noxious weeds and invasive species known to be on or near the site. Invasive species are common along the riverbank, including Himalayan blackberry, reed canary grass, and Japanese knotweed. 5. Animals a. List any birds and other animals which have been observed on or near the site or are known to be on or near the site. Examples include: birds: hawk, heron, eagle, songbirds, other: mammals: deer, bear, elk, beaverother: fish: bass, salmon, trout, herring, shellfish, other Fish and wildlife use of the project area is limited by its high density of industrial, commercial, and residential development. Terrestrial wildlife habitat in the project area is limited to the narrow riparian fringe along the Duwamish River. Aquatic habitat is limited to the Duwamish River, which contains a wide range of native and nonnative fish species. Anadromous fish use in the Duwamish River is described below. Documented Fish—Duwamish River and Tributaries within Project Area WDFW Salmonscape Data WDFW PHS Data • Documented rearing habitat for fall Chinook, fall chum, and coho in Duwamish River. • Includes occurrence areas for Chum, Steelhead, Bull Trout, • Documented presence of fall chum, winter and summer Chinook, and Coho. steelhead, and sockeye, bull trout, and pink salmon in • Includes threatened areas for Duwamish River. Steelhead, Bull Trout, and • Documented presence of coho in local tributaries. Chinook. • Threatened, accessible Evolutionarily Significant Units • Includes Candidate areas for (ESUs) for spring Chinook, summer Chinook, fall Chinook, and pink (odd year). Coho. • Species of concern, accessible ESUs for coho. • Threatened, accessible DPSs for winter and summer steelhead. ( SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 12 of 23 According to WDFW PHS data, no occurrences of priority habitats or species are documented in the project area, other than the fish species described above. The majority of the new road would affect a currently developed area. Impacts on fish in the Duwamish River could be minimized by keeping work outside the OHWM. This alternative would have impacts to the narrow riparian habitat zone on both sides of the Duwamish River. b. List any threatened and endangered species known to be on or near the site. Fish use in the Duwamish River includes several species listed as threatened species under the federal Endangered Species Act (ESA), including Chinook salmon, steelhead trout, and bull trout. These species use the portion of the river in the project area as migration habitat to and from marine waters and upstream spawning and rearing areas higher in the watershed. This portion of the Duwamish River is also designated critical habitat for bull trout and Chinook salmon. c. Is the site part of a migration route? If so, explain. Chinook salmon, steelhead trout, and bull trout use the portion of the river in the project area as migration habitat to and from marine waters and upstream spawning and rearing areas higher in the watershed. d. Proposed measures to preserve or enhance wildlife, if any: The project is located in an urban and industrial setting. Limited wildlife habitat exists on the project site. No measures will be employed to preserve or enhance wildlife. e. List any invasive animal species known to be on or near the site. No invasive animal species are known to occur in or near the site. 6. Energy and Natural Resources a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project's energy needs? Describe whether it will be used for heating, manufacturing, etc. During construction, electricity, gasoline, diesel fuel, and oil would be used for lighting, vehicles, and equipment. In the long run, after construction is complete, the project would not have energy needs beyond those needed for maintenance. b. Would your project affect the potential use of solar energy by adjacent properties? If so, generally describe. No, this project would not affect potential use of solar power by adjacent properties. 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: This project does not include energy conservation measures beyond those listed in (6)(a). SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 13 of 23 7. Environmental Health a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur as a result of this proposal? If so, describe. No environmental health hazards will occur as a result of the project, other than the unlikely occurrence of a hazard or accident related to fuel spilling from construction vehicles or equipment. 1) Describe any known or possible contamination at the site from present or past uses. The Duwamish River is on the Ecology 303(d) list for several water quality measures or pollutants, including temperature, dissolved oxygen, pH, bacteria, ammonia, and several other pollutants. GeoEngineers has prepared a Hazardous Materials Alternatives Analysis (see Attachment C) to address the potential for encountering contamination within the project area. Due to the long-term history of development and heavy industrial use in the project area, and to the extent ground is disturbed, hazardous materials issues and contamination issues will need to be addressed. See Attachment C for more information. The contractor will comply with environmental regulations and current rules of resource agencies, according to WSDOT Standard Specifications Section 1-07.5. The Contractor will follow the WSDOT Environmental Procedures Manual (31-11), Chapter 620.08, which provides policy and procedures for identifying, handling and disposing of hazardous materials encountered during construction. The Construction Manual (M41-01), Section 1-2.2K provides guidance and procedures to ensure environmental compliance during construction. 2) Describe existing hazardous chemicals/conditions that might affect project development and design. This includes underground hazardous liquid and gas transmission pipelines located within the project area and in the vicinity. No underground hazardous liquid or gas transmission pipelines are located within the project area. The closest pipeline is a hazardous liquid pipeline running northwest -southeast between Beacon Avenue S and Renton Avenue S, approximately 0.75 mile northeast of the project. 3) Describe any toxic or hazardous chemicals that might be stored, used, or produced during the project's development or construction, or at any time during the operating life of the project. Toxic or hazardous chemicals stored, used, or produced during construction or long-term operation of the project could include cleaners, gasoline and oil for construction vehicles and equipment, and paint. 4) Describe special emergency services that might be required. In the event of an emergency during construction, emergency response would be required. After construction, no additional emergency services would be required other than those serving the road and bridge. 5) Proposed measures to reduce or control environmental health hazards, if any: No environmental health hazards are expected on- or off -site as a result of this project. SEPA Environmental checklist (WAC 197-11.960) Form Updated May 2014 Page 14 of 23 b. Noise 1) What types of noise exist in the area which may affect your project (for example: traffic, equipment, operation, other)? Traffic, train, and airport noise sources already exist in the area, Interstate 5 in particular, and would not affect the project. No additional sensitive receptors would be present due to the project's construction or long-term operation. 2). What types and levels of noise would be created by or associated with the project on a short-term or a long-term basis (for example: traffic, construction, operation, other)? Indi- cate what hours noise would come from the site. Short-term noise from construction equipment would occur during appropriately set hours (see [7][b][3]). The increased noise generated during construction would be temporary and would last the length of the construction period. Noise receptors near the project site include the Days Inn at 48th Avenue S and homes west of the railyard, between 51st Place S and 50th Place S. In the long run, the project would change the vertical and horizontal alignment of the roadway, which is likely to increase traffic noise in the surrounding area and at the noise receptors. Currently, 48th Avenue S serves industrial and commercial traffic. The project would result in higher noise levels in the immediate area due to increased industrial traffic through the area. Guests at the Days Inn could experience intermittently higher noise levels. Homes west of the railyard, between 51st Place S and 50th Place S could experience more truck noise due to the use of the area west of 51st Place S as a truck queuing area. These noises will not be inconsistent with the already -existing air, rail, and truck traffic noise in the project area. 3) Proposed measures to reduce or control noise impacts, if any: The proposed project will comply with the City of Tukwila noise regulations. Mitigation measures could include the following: • limit construction activity to daytime hours; • use electric rather than diesel or gas -powered machines where practical; • use mufflers on all internal combustion engine -driven equipment; • turn off idling equipment. 8. Land and Shoreline Use a. What is the current use of the site and adjacent properties? Will the proposal affect current land uses on nearby or adjacent properties? If so, describe. The current use of the site is transportation. The existing 48th Avenue S is bordered by light industrial uses and one two-story hotel. YRC Freight, a trucking and logistics company, is located at the east end of the existing street. No neighborhoods are located along this route. The proposal would result in additional truck traffic, which could increase noise at the hotel. Other uses are industrial and are therefore not as sensitive to noise increases. b. Has the project site been used as working farmlands or working forest lands? If so, describe. How much agricultural or forest land of Tong -term commercial significance will be converted to other uses as SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 15 of 23 a result of the proposal, if any? If resource lands have not been designated, how many acres in farmland or forest land tax status will be converted to nonfarm or nonforest use? The project site has not likely been used in recent history as farmland or forest land. 1) Will the proposal affect or be affected by surrounding working farm or forest land normal business operations, such as oversize equipment access, the application of pesticides, tilling, and harvesting? If so, how: The project would not affect or be affected by working farm or forest land operations; none are located near the project site. c. Describe any structures on the site. Commercial and industrial buildings border 48th Avenue S on both sides. Buildings on the northwest side of the 48th Avenue S include a large industrial warehouse/trucking facility nearest the river, two smaller warehouses/trucking facilities, and a gas station/mini-mart. The southeast side structures include a gas station nearest Interurban Avenue S, Days Inn, and two buildings related to trucking, distribution, or warehousing. d. Will any structures be demolished? If so, what? No buildings will be demolished. Some roadway -related structures or roadway pieces may be removed or relocated as part of the project. e. What is the current zoning classification of the site? The 48th Avenue S area is zoned for Commercial Light Industrial. f. What is the current comprehensive plan designation of the site? The 48th Avenue S area is planned for Commercial Light Industrial in the City's May 2015 Comprehensive Plan. g. If applicable, what is the current shoreline master program designation of the site? The project area falls within Tukwila's shoreline jurisdiction. Based on City of Tukwila Shoreline Management Act guidelines, Tukwila's shoreline jurisdiction includes the channel of the Duwamish River, its banks, the upland area which extends from the OHWM landward for 200 feet on each side of the river, floodways, and all associated wetlands within its floodplain. For the purpose of determining shoreline jurisdiction only, the City's SMP states that the floodway shall not include those lands that have historically been protected by flood control devices and, therefore, have not been subject to flooding with reasonable regularity. The City of Tukwila identifies the shoreline within the project site as Urban Conservancy, the purpose of which is to protect and restore ecological functions of open space, flood plain, and other sensitive lands in urban and developed settings, while allowing a variety of compatible uses. h. Has any part of the site been classified as a critical area by the city or county? If so, specify. SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 16 of 23 The City identifies the Duwamish River and riverbanks sloped up to 40 percent critical areas with the project site. Riverbanks include areas sloping between 15 percent and 40 percent and underlain by permeable soils and are sloping more than 15 percent and underlain by impermeable soils or bedrock. i. Approximately how many people would reside or work in the completed project? No one would reside in the completed project. j. Approximately how many people would the completed project displace? No one would be displaced by the completed project. k. Proposed measures to avoid or reduce displacement impacts, if any: No measures are needed because no displacements will occur. I. Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any: No measures are necessary. The project would not result in any permanent changes to existing land uses, although it would require land acquisition (approximately 25,000 square feet — land use conflicts would be minimal along 48th Avenue S due to the existing industrial and commercial uses along and adjacent to 48th Avenue S). The project is compatible with future land use plans, as the uses would remain the same, except fo tithe small amount of land converted to transportation right-of-way. m. Proposed measures to ensure the proposal is compatible with nearby agricultural and forest lands of long-term commercial significance, if any: No measures are necessary. No agricultural or forest lands of long-term commercial significance are located near the project. 9. Housing a. Approximately how many units would be provided, if any? Indicate whether high, mid- dle, or low-income housing. No housing units would be provided as part of the proposed project. b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or low-income housing. No housing units would be eliminated due to the project. c. Proposed measures to reduce or control housing impacts, if any: No measures are proposed because no impacts to housing will occur. SEPA Environmental checklist (WAC 197.11-960) Form Updated May 2014 Page 17 of 23 10. Aesthetics a. What is the tallest height of any proposed structure(s), not including antennas; what is the principal exterior building material(s) proposed? The principal material proposed for the roadway improvements and bridge is concrete. The tallest height of any proposed structure would likely be the bridge over the Duwamish River, which would be 25 feet over the river, unless light poles are placed on the bridge. If lighting is placed on the bridge, the top of the light poles would be 60 feet above the river (the light poles would be 35 feet high). b. What views in the immediate vicinity would be altered or obstructed? On a permanent basis, views would be altered due to the new bridge over the river. The proposed bridge would be visible to nearby employees and patrons of the businesses at the east end of 48th Avenue S, Green River Trail users, residents of south Allentown, Codiga Park visitors, and drivers on Interstate 5 and S 129th Street. The additional bridge would not be inconsistent with existing views — two overcrossing structures are located within 300 feet of where the new bridge will cross the river: (1) Interstate 5 crossing over the river and the railroad, and (2) S 129th Street crossing over the railroad. Views would temporarily change during construction due to construction activities. c. Proposed measures to reduce or control aesthetic impacts, if any: No measures are required because no major permanent adverse impacts to aesthetics would occur. 11. Light and Glare a. What type of light or glare will the proposal produce? What time of day would it mainly occur? New illumination would be provided commensurate with the proposed expanded use of 48th Avenue S and the proposed bridge. The purpose of the lighting would be to provide safety and security along the route, and would operate during nighttime hours. b. Could light or glare from the finished project be a safety hazard or interfere with views? Light from the finished project would not likely be a safety hazard or interfere with views because lights would only operate at night, for the purpose of safety and security. c. What existing off -site sources of light or glare may affect your proposal? During nighttime hours, lighting exists at nearby industrial and commercial properties. However, these existing sources of light or glare would not affect the proposal. d. Proposed measures to reduce or control light and glare impacts, if any: None are necessary because no light or glare impacts would occur. SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 12. Recreation a. What designated and informal recreational opportunities are in the immediate vicinity? The Green River Trail extends through the project area between the Duwamish River and the eastern/northeastern terminus of 48th Avenue S. Codiga Park is located within approximately 0.1 mile of the project. b. Would the proposed project displace any existing recreational uses? If so, describe. The project will not permanently affect the Green River Trail. However, it will result in the removal and relocation of 7 parking spaces at the east end of 48th Avenue S, which are likely used for trail access. The picnic table currently located near the trail will also be removed and relocated. The Green River Trail will be temporarily detoured during construction. A trail detour will be in place for approximately one to three months, while the contractor hangs the bridge girders. The trail detour will begin where Interurban Avenue meets the northbound entrance to Interstate 5. Trail users will follow the detour northwest on Interurban Avenue and re-enter the Green River Trail at the north end of the Gateway Corporate Center by using Access Roadway to meet the trail. The new extended 48th Avenue S would be separate from the Green River Trail where it would cross the trail, resulting in minimal conflicts between truck traffic and trail users. Impacts to the trail would be evaluated under Section 4(f) of the US Department of Transportation Act of 1966, and would likely require a Temporary Occupancy form. c. Proposed measures to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any: A replacement picnic table and parking spaces for trail users will be constructed near the existing location. 13. Historic and cultural preservation a. Are there any buildings, structures, or sites, located on or near the site that are over 45 years old listed in or eligible for listing in national, state, or local preservation registers located on or near the site? If so, specifically describe. Historical Research Associates, Inc. (HRA) found that on the 1863 General Land Office plat, the project access route crosses land claimed by C. C. Lewises and Stephen Foster west of the Duwamish River and Bennett L. Johns' claim on the east bank of the river. The Seattle Tacoma Electric Rail Road ran perpendicular to the western end of the project site by 1907. It is mapped as the Seattle Tacoma Interurban Railway between 1912 and 1936. By 1936, the track had been abandoned. Interstate 5 was constructed in the 1960s. The large office building adjacent and to the north of the proposed route, west of the Duwamish River, was constructed between 1968 and 1969. Additional commercial/industrial buildings appear north of the project site by 1980 (see Attachment D Cultural Resources Report for more information). The project area includes 13 parcels, five of which have buildings, structures, or objects (BSOs) over 35 years of age (listed below). The BSOs range in build date, from the oldest in 1969 to the youngest in 1980. None of the BSOs have been evaluated for NRHP eligibility. SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 19 of 23 Parcel 000300-0030 000480-0018 000300-0109 000380-0003 000480-0013 Address 13050 48th Ave S 98168 12840 48th Ave S 98168 13123 Interurban Ave S 98168 12200 51st PI S 98178 12855 48th Ave S 98168 Year Built (1980+) 1980 1976 1975 1970 1969 Landmark Status Undetermined Undetermined Undetermined Undetermined Undetermined Although right-of-way acquisition will occur on both sides of 48th Avenue S, no displacements will occur. The parcel with the largest acquisition will be parcel 0004800013, located at the end of 48th Avenue S on the north side. b. Are there any landmarks, features, or other evidence of Indian or historic use or occupation? This may include human burials or old cemeteries. Are there any material evidence, artifacts, or areas of cultural importance on or near the site? Please list any professional studies conducted at the site to identify such resources. The project is positioned on a point bar that has grown to the northeast as the river meandered in that direction. Sediments in the far southwestern portion of the project site are covered in a thin layer (2 to 5 feet) of fill that overlies alluvium. The project site has a high potential to contain near -surface or more deeply buried archaeological deposits on both sides of the river. The project site is within an area identified by local Native American groups as a traditionally important landscape. Traditional Cultural Properties (TCPs) are known in the vicinity of the project site. Historical Research Associates, Inc. (HRA) recommends consultation take place with local Native American groups and DAHP regarding the project's possible effects/impacts on ethnographically important places and TCPs. Archaeological site 45KI538 is adjacent to or within the project site, as discussed in further detail in Attachment D Cultural Resource Report. HRA recommends evaluation of 45KI538 for NHRP, WHR, and King County Landmark List Eligibility; if this site is eligible for a local, state, or national register, then additional cultural resources procedures (i.e., mitigation) may be required. See Attachment D, Cultural Resources Report, for further information. c. Describe the methods used to assess the potential impacts to cultural and historic resources on or near the project site. Examples include consultation with tribes and the department of archeology and historic preservation, archaeological surveys, historic maps, GIS data, etc. HRA conducted an archival record search for records pertaining to locations within a 0.25-mile search radius of the project. HRA searched the DAHP's online database, the Washington Information System for Architectural and Archaeological Records Data (WISAARD), for cultural resource survey reports, archaeological site records, historic property inventory (HPI) forms, historic register information, and cemetery records. HRA also reviewed a statewide archaeological predictive model on DAHP's WISAARD for probability estimates for archaeological resources. d. Proposed measures to avoid, minimize, or compensate for loss, changes to, and disturbance to resources. Please include plans for the above and any permits that may be required. SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 20 of 23 The project will comply with Section 106 of the National Historic Preservation Act. If required by DAHP, a cultural resource survey and inadvertent discovery plan (IDP) will be prepared. An IDP will set forth procedures and steps to take if an inadvertent discovery occurs. 14. Transportation a. Identify public streets and highways serving the site or affected geographic area and describe proposed access to the existing street system. Show on site plans, if any. The site is accessed via Interurban Avenue S from the west, from Interstate 5 or SR 599. Vehicle access to the area will not change with the project. b. Is the site or affected geographic area currently served by public transit? If so, generally describe. If not, what is the approximate distance to the nearest transit stop? Sound Transit's Central Link light rail runs along the western boundary of Allentown, on E Marginal Way South, and Interurban Avenue S. The Sounder commuter rail train uses the BNSF Railway rail lines along the eastern boundary of Allentown, and stops at 7301 Longacres Way in Tukwila. Sound Transit bus routes 577, 578, 586, 590, and 592 travel near the site on Interstate 5. King County Metro Transit route 124 from Tukwila to Seattle is accessible from near the project site on Pacific Highway South. c. How many additional parking spaces would the completed project or non -project proposal have? How many would the project or proposal eliminate? The new project would not provide any additional parking spaces. It would result in the removal of 7 spaces along 48th Avenue S, at the east end of the street. These are likely used by Green River Trail users. d. Will the proposal require any new or improvements to existing roads, streets, pedestrian, bicycle or state transportation facilities, not including driveways? If so, generally describe (indicate whether public or private). The project involves improvement to 48th Avenue S, as well as Interurban Avenue S and S 129th Street at their intersections with 48th Avenue S. e. Will the project or proposal use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe. The project would occur near and provide a relocated access route for trucks to the BNSF railyard. Air and rail transportation is nearby. The project will not use water or air transportation. f. How many vehicular trips per day would be generated by the completed project or proposal? If known, indicate when peak volumes would occur and what percentage of the volume would be trucks (such as commercial and nonpassenger vehicles). What data or transportation models were used to make these estimates? No change in number of vehicle trips would occur with the project. Truck trips will move from S 124th Street to 48th Avenue S. g. Will the proposal interfere with, affect or be affected by the movement of agricultural and forest products on roads or streets in the area? If so, generally describe. SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 21 of 23 The project would not adversely affect movement of agricultural and forest products on streets in the area. During construction, access would be maintained at all times, and vehicles (including freight) could experience temporary delays. In the long run, safety and throughput capacity for the route to and from the BNSF railyard will improve. h. Proposed measures to reduce or control transportation impacts, if any: During construction, access to businesses would be maintained. No vehicles detours would be necessary, although temporary and intermittent one -lane closures on 48th Avenue S and Railroad Avenue will occur. No measures are proposed because no permanent adverse transportation impacts are expected to occur. 15. Public Services a. Would the project result in an increased need for public services (for example: fire protection, police protection, public transit, health care, schools, other)? If so, generally describe. No permanent increase in demand for public services, such as fire and police protection and public transit, would occur as a result of the project. The project would not result in additional housing units and therefore is not expected to result in an increase in demand for health care or schools. b. Proposed measures to reduce or control direct impacts on public services, if any. None are proposed because impacts to public services are expected to be minimal. 16. Utilities a. Circle utilities currently available at the site: electricity!, natural gas water, refuse service, other telephone sanitary sewer septic system, 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. Utilities will remain the same at the project site, with the exception that the existing closed stormwater detention system will be reconstructed. A storage and water quality vault may need to be constructed to accommodate the project. Stormwater runoff will be managed in accordance with the Ecology 2012 Stormwater Management Manual for Western Washington. Also, BMPs will be employed in accordance with the same manual. SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 22 of 23 C. SIGNATURE 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: .-6?t ,Iii,eA0-0-1 Nameofsignee Soli 0 ME/S-Oli\% Position and Agency/Organization Pt-fgt.-4 L` 4' J D) 2�re-vt'() C Cry °r Tvl 1 Date Submitted: )2-7-9—/6 List of Attachments: Attachment A Attachment B Attachment C Attachment D Attachment E Alternative Analysis Screening Report Geotechnical Report Hazardous Materials Memorandum Cultural Resources Report NW Maps sensitive areas SEPA Environmental checklist (WAC 197-11-960) Form Updated May 2014 Page 23 of 23 ATTACHMENT A Alternative Screening Analysis Report JAN 05 2017 MiiLV Ui Mir i r BNSF RAILWAY INTERMODAL FACILITY ACCESS STUDY ALTERNATIVE SCREENING ANALYSIS REPORT Prepared for: City of Tukwila Public Works Department 6300 Southcenter Boulevard Tukwila, WA 98005 RECEIVED JAN052017 rnMniurvrry _LV/LLOI'MI NT Prepared by: David Evans and Associates, Inc. 14432 SE Eastgate Way Bellevue, WA 98007 December 2016 TABLE OF CONTENTS EXECUTIVE SUMMARY 1 INTRODUCTION 2 PROJECT BACKGROUND 2 SUMMARY OF DESIGN CRITERIA 2 ALTERNATIVES 2 Airport Way S Alternative 4 S 112th Street Alternative 4 S 124th Street Alternative 4 Gateway Drive Alternative 5 48th Avenue S Alternative 5 SUMMARY OF BACKGROUND DATA COLLECTION 6 Critical and Sensitive Areas 6 Fish and Wildlife 6 Water Resources 6 Hazardous Materials 7 Geological and Soils 7 Cultural and Historical Resources 7 SCREENING MATRIX 7 Matrix Criteria 8 Scoring Methodology 10 SCORING OF ALTERNATIVES 11 CONCEPTUAL CONSTRUCTION COSTS AND RIGHT-OF-WAY ESTIMATES 13 CONCEPTUAL PLAN SHEETS 13 LIST OF FIGURES Figure 1— Project Study Area 3 Figure 2 — Selection Criteria Screening Matrix 12 APPENDICES Appendix A — Alternative Plan Sheets Appendix B — Truck Access Routes Appendix C — Roadway Cost Estimate Back-up H:1003 - Pro/ectsIBNSFaccesslSEPAIScreening SummaryiBNSF Intermodal Access Screening summary _2016-1126.docx City of Tukwila i Alternative Screening Analysis BNSF Intermodal Facility Access December 2016 EXECUTIVE SUMMARY This Alternative Screening Analysis Report for the City of Tukwila was prepared by David Evans and Associates, Inc. to evaluate alternative access to the BNSF Railway Intermodal Facility in Tukwila (12400 51st Place South, Tukwila WA 98178) The existing access to the intermodal facility uses 42nd Avenue S and S 124th Street. S 124th Street is also a residential collector street serving the community of Allentown. Several residential homes with driveways are located on S 124th Street, as is the Tukwila Community Center which houses an aquatic center, meeting rooms, classes and activities for all ages, and playground and ball fields. This study did not create new alternatives but used alternatives that were developed by previous studies. A total of five alternatives were studied: Airport Way S, S 112th Street, S 124th Street, Gateway Drive — North Leg, and 48th Avenue S. Several desktop researches were performed as part of this study. These researches included critical and sensitive areas, fish and wildlife, water resources, hazardous materials, geological and soils, and cultural and historical resources. A scored screening matrix was developed collaboratively between the City of Tukwila, BNSF Railway, and David Evans and Associates, Inc. The matrix was presented to Tukwila City Council as well as to the public for their feedback on the screening matrix criteria. The public was allowed to provide feedback via an on-line open house and an in -person open house. Representatives from Tukwila, BNSF Railway, and David Evans and Associates, Inc. met to score each alternative using a numerical scoring system from 1 to 9. The score for each criteria was added, and the lowest score is the preferred alternative. Based on the scoring result, the 48th Avenue S alternative is the preferred alternative. H:I003 - Projects1BNSF accessiSEPAIScreening SummarylBNSF Intermodal Access Screening summary _2016-1128,docx City of Tukwila 1 Alternative Screening Analysis BNSF Intermodal Facility Access December 2016 INTRODUCTION BNSF Railway owns an intermodal facility that transfers containers from trucks to railroad and vice versa. This facility is located within the City of Tukwila city limits in the Allentown community. The intermodal facility is adjacent to Interstate 5 (1-5) and just south of King County International Airport, also known as Boeing Field. BNSF calls this facility the South Seattle Intermodal Facility. The only access route to the intermodal facility is along the southern edge of the Allentown community on S 124th Street. In order to improve livability and safety without compromising the operations of the yard, the community and the City are seeking an alternative access route to the intermodal facility. PROJECT BACKGROUND The project area is located in the incorporated community of Allentown, within the City of Tukwila. For several years, the City has worked with Allentown residents on issues related to community impacts resulting from the BNSF South Seattle Intermodal Facility, and on identifying alternatives for a rerouted truck access —one with fewer adverse impacts on the neighborhood. Trucks currently use 42nd Avenue S and S 124th Street to access the rail facility. Over 20 different alternatives for truck access to the rail facility have been studied since 1998. Truck traffic has increased along the existing truck route over the last several years, due to increased rail activity. The approximately 50 homes along S 124th Street experience 24-hour per day truck traffic, adding to the other existing airport, highway, and train noise levels in the neighborhood. Truck traffic also creates safety issues for residents. Trucks back up at the checkpoint station at the east end of S 124th Street, idling on S 124th Street, waiting to check into the rail facility, creating access difficulties, vehicle exhaust, noise, and safety issues for residents. SUMMARY OF DESIGN CRITERIA After discussions with the City, the typical roadway section for this project used a 12-foot lane, 5- foot bike lane, 5-foot landscape strip, and 5-foot sidewalk. The total width for this roadway section is 75 feet (includes 1-foot for curbs on both side of the street). This same width was also used for the bridge section. In developing the concept roadway profiles, a design speed of 35 mph was used. Since the new access would primarily be used by trucks, the maximum roadway grade used was five percent. ALTERNATIVES The City of Tukwila began studying access alternatives to the BNSF Intermodal Facility in 1998. An alternative study was performed by Harding Lawson Associates. Another access alternative study was performed by Cooper Consulting Engineering in 2000. This access study did not develop new alternatives, but used leading alternatives from these previous studies. Figure 1 shows the project study area. The following provides a description for each alternative. H.1003 • ProiectslBNSF exesslSEPAIScreenrng Summery%BNSF Intermodal Access Screening summery_2016-1128 docx City of Tukwila 2 Alternative Screening Analysis BNSF Intermodal Facility Access December 2016 Figure 1— Project Study Area ‘"N‘• -A-, N - A -• '77 r, si • v`' - NA 1:?..A Airport Way ?<: ir Alternative i'F-1411U, Gateway Drive Extension Alternative City of Tukwila BNSF Intermodal Facility Access H 1003 - Projects1BNSF accessSEPAIScreening SummarylBNSF Intermodal Access Screening summary .20 f 6-1128 docx 3 Alternative Screening Analysis December 2016 Airport Way S Alternative This alternative access would connect the northern end of the intermodal facility to Airport Way S. The existing railroad maintenance road would be reconstructed and provide ingress and egress to the intermodal facility. A new intersection and traffic signal would be required at Airport Way and the access road. Plan sheets for this alternative can be found in Appendix A. Due to geometric constraints and the alignments of Airport Way S and the new access road, access from Airport Way south of the new intersection to the intermodal facility is not feasible. Entry and exit from the intermodal facility would only be north of the new intersection. Taking into account these restrictions, 1-5 freeway access would be via S Norfolk Street, East Marginal Way S, and S Boeing Access Road. A figure of the truck freeway access route can be found in Appendix B. This alternative access would require the existing bridge on S Boeing Access Road over the railroad tracks to be reconstructed due to the width of the new access road and the existing bridge configuration. This alternative would require the intermodal facility to construct the following at the north end of the yard: a check-in/check-out facility, truck queuing lanes, an operations building, and a truck storage access road along the western edge of the facility. This new road cannot be built within the existing BNSF parcel, so new right-of-way would be required. S 112th Street Alternative This alternative would connect to the northern half of the intermodal facility. This new roadway would begin at East Marginal Way S and use the existing Seattle Public Utilities and Seattle City Light utilities corridor. The utilities corridor borders a shooting range to the north, and Duwamish Hill Preserve and a residential neighborhood to the south. A bluff separates the higher -elevation residential neighborhood from S 112th Street to the north and the rail facility to the east. The existing utility corridor contains three separate high -power transmissions lines and a large - diameter water line, as seen in aerial photos. Plan sheets for this alternative can be found in Appendix A. The truck freeway access route to 1-5 would be via East Marginal Way S and S Boeing Access Road. A figure of the truck freeway access route can be found in Appendix B. This alternative would require the intermodal facility to construct the following at the north end of the yard: a check-in/check-out facility, truck queuing lanes, an operations building, and a truck storage access road along the western edge of the facility. This new road cannot be built within the existing BNSF parcel, so new right-of-way would be required. S 124th Street Alternative This alternative would use the existing route and connect into the intermodal facility at its current location. Truck traffic would continue to access the rail facility using Interurban Avenue S, 42nd Avenue S, S 124th Street, and the existing check-in/check-out facility. No improvements or changes would occur to the streets along the route as part of this project. This route is adjacent to H:1003-ProjectslBNSFaccesslSEPAIScreen,ngSummary1BNSFlnlermodalAccessScreeningsummary_2016-1128.docx City of Tukwila 4 Alternative Screening Analysis BNSF Intermodal Facility Access December 2016 approximately 50 homes and the Tukwila Community Center, and runs through the middle of the Allentown neighborhood. Impacts to the neighborhood associated with the truck traffic would continue, similar to existing conditions, and could continue to worsen, based on recent increases in freight -related truck traffic in this area. Due to its age and service life, the 42nd Avenue S bridge over the Duwamish River would require replacement. Plan sheets for this alternative can be found in Appendix A. As a mitigation measure for the truck noise, it is assumed that a noise wall would be constructed along the northern edge of 42nd Avenue S. The construction of this new noise wall would require the acquisition of all homes whose driveways are on 42nd Avenue S. Also, seven roadways (43rd Avenue S, 44th Avenue S, 45th Avenue S, 46th Avenue S, 47th Avenue S, 48th Avenue S, and 49th Avenue S) would have their access to 42nd Avenue S closed. These streets would become dead-end streets, and new cul-de-sacs would be constructed at the south end of each street. All of the neighbor access would be shifted to S 122nd Street to the north. There would be no changes to freeway access with this alternative. A figure of the truck freeway access route can be found in Appendix B. There would be no changes to the intermodal facility as part of this alternative. Gateway Drive Alternative This alternative access would connect to the intermodal facility at its current check-in/check-out location. This alternative would begin at Interurban Avenue S, use the north leg of Gateway Drive, construct a new roadway between the Boeing Employee Credit Union (BECU) buildings, construct a bridge over the Green River Trail and Duwamish River, go through residential parcels, and tie into the existing intermodal check-in/check-out facility. This alternative would construct three new at - grade intersections at Gateway Drive (east leg), 50th Place S, and 51st Place S. The new bridge would include a 10-foot-wide pedestrian facility. Plan sheets for this alternative can be found in Appendix A. The truck freeway access route to 1-5 would be via Interurban Avenue S. A figure of the truck freeway access route can be found in Appendix B. There would be no changes to the intermodal facility as part of this alternative. 48th Avenue S Alternative This alternative access would connect to the southern end of the intermodal facility. This alternative would begin at Interurban Avenue S, use the existing 48th Avenue S roadway, and construct a new bridge over the Green River Trail and Duwamish River, as well as a roadway that goes under the existing S 129th Street bridge and into the rail yard facility. The new bridge would include a 10-foot-wide pedestrian facility. Plan sheets for this alternative can be found in Appendix A. The truck freeway access route to 1-5 would be via Interurban Avenue S. A figure of the truck freeway access route can be found in Appendix B. H:1003 - Projecls1BNSFaccesslSEPAIScreening SummarylBNSF lnfermodal Access Screening summary_2016-1126.docx City of Tukwila 5 Alternative Screening Analysis BNSF Intermodal Facility Access December 2016 This alternative would require the intermodal facility to construct new truck queuing and exiting lanes. All new lanes can be constructed within BNSF parcels. No construction or modification would be needed at the existing check-in/check-out facility or operation building. SUMMARY OF BACKGROUND DATA COLLECTION To assist in screening the alternatives, existing information in the following subjects was gathered and displayed as geographic information system (GIS) maps. No field work was conducted, and the information for the existing conditions came from publicly -available sources. An Existing Conditions Technical Memorandum was prepared for each subject area. This information will also be used in the technical discipline reports prepared as part of the environmental documentation under SEPA. • Critical and Sensitive Areas • Fish and Wildlife • Water Resources • Hazardous Materials • Geological and Soils • Cultural and Historical Resources The following sections provide a summary of the findings. Critical and Sensitive Areas The project area is located in the Puget Sound lowlands, within the tidally -influenced Duwamish estuary ecosystem. Category III and IV wetlands exist within the project study area. The Duwamish River runs through the middle of the project area and is designated by the City of Tukwila as a shoreline of statewide significance. Fish and Wildlife Fish and wildlife use of the project study area is limited by its high density of industrial, commercial, and residential development. Terrestrial wildlife habitat in the project area is limited to the buffers of wetlands, the narrow riparian fringe along the Duwamish River, and a few scattered undeveloped steep slopes and undeveloped parcels. Fish use in the Duwamish River, which contains a wide range of native and nonnative fish species, includes several species listed as threatened species under the federal Endangered Species Act (ESA), including Chinook salmon, steelhead trout, and bull trout. Water Resources According to the King County Aquifer Recharge Area map, no critical aquifer recharge areas are located within the project area. Since the Duwamish River is a designated floodway that is contained by constructed levees, there are no 100-year or 500-year floodplains located within the project study area. All alternatives fall within Tukwila's shoreline jurisdiction. H:1003 Pr%cSsIBNSF access1SEPAIScreening Summary1BNSF Intermodal Access Screening summary _2016-1128.docx City of Tukwila 6 Alternative Screening Analysis BNSF Intermodal Facility Access December 2016 The Duwamish River is on the Ecology 303(d) list for over 300 water quality pollutants. Hazardous Materials Hazardous material sites were identified within the project study area. Each site was assigned a risk rating (low, medium, or high). The risk assigned was based on professional judgment considering each site's distance to the alternative footprint, type, duration of historical development, contaminated media, known gradient and contaminant migration potential. The majority of the sites were classified as low risk. Concerns exist based on historical or current development, but the likelihood for conditions at the site to affect the project is assessed as relatively low. Geological and Soils The project study area is located within the Duwamish River valley. Prior to human modifications. the Duwamish River was a natural distributary channel of the Cedar and Green Rivers, as well as the White River. These rivers originate on the flanks of Mount Rainer. Predominate geologic units mapped in the area of the proposed route alternatives include: alluvium, bedrock, and glacial deposits. The alternative routes are primarily located within the areas mapped as alluvial deposits. Bedrock is mapped along the southeastern edge of the Duwamish River valley in the project study area. Exposed bedrock outcrops are also mapped in the northern portion of the project area while a glacial deposit area was mapped along the southwestern edge of the project study area. In general, there are relative good soils within the project area; however, the potential of liquefaction does exist within the project study area, especially along the riverbanks. Cultural and Historical Resources The project study area is within an area identified by local Native American groups as a traditionally important landscape. Traditional cultural properties are known to be in the vicinity of each access alternative. Remnants of electric railroad may be located at the western ends of all of the alternatives, and would be considered as items of archaeological importance if encountered. The project study area contains several buildings, structures, and objects (BSO) that are 35 years or older. The majority of these BSOs are residential homes. Survey and elevations need to be performed to determine if they are eligible for registry. SCREENING MATRIX In the following two sections, an explanation of the selection criteria matrix is presented. The first section, Matrix Criteria, discusses the criteria groups and each individual criterion. The second section, Scoring Methodology, discusses the approach used to score each alternative. H:1003 - ProjeclsISNSFaccess1SEPAIScreening SummarylBNSF lnfermodel Access Screening summary_2016-1128.docx City of Tukwila 7 Alternative Screening Analysis BNSF Intermodal Facility Access December 2016 Matrix Criteria A screening matrix was developed to score the alternatives. The City of Tukwila, BNSF Railway, and David Evans and Associates, Inc. worked collaboratively to create the screening matrix. The matrix was then presented to the City Council and the public for their comments. Bob Giberson, Tukwila Public Works Director, presented the screening matrix to the City Council. The City Council did not have any comments on the screening matrix. The screening matrix was presented to the public via two venues: an on-line open house and an in - person open house. The public did not have any comments on the screening matrix. The screening matrix contained four groups of scoring criteria. The groups and group descriptions are as follow: • Right-of-Wav This group evaluates the need for new right-of-way to construct the alternative and railroad yard modifications and the complexity or difficulties in obtaining the new right- of-way. • Construction This group evaluates the complexity, difficulties, and impacts of constructing the alternatives. • Railroad This group evaluates the complexity, difficulties, and impacts to the operations of the existing railroad intermodal facility. • Environmental This group evaluates the complexity, difficulties, and impacts to the environment, preparing the required environmental documentation, and obtaining construction permits. For each of these groups, more in depth scoring criteria were used. The following section describes these additional scoring criteria. Right -of -Way • Residential This criterion evaluates the need for new residential right-of-way to construct the alternative, and the complexity or difficulties in obtaining the new residential right-of- way. • Commercial This criterion evaluates the need for new commercial right-of-way to construct the alternative, and the complexity or difficulties in obtaining the new commercial right-of- way. H.I003-ProjectslBNSFaccesslSEPAIScreeningSummarytBNSFInlermodalAccessScreeningsummary_2016-1128.docx City of Tukwila 8 Alternative Screening Analysis BNSF Intermodal Facility Access December 2016 • Vacant Land This criterion evaluates the need for new vacant land right-of-way to construct the alternative, and the complexity or difficulties in obtaining the new vacant land right-of- way. Construction • Utilities Relocation This criterion evaluates the complexity or difficulties of relocating existing utilities (power, telephone, gas, water, etc.). A couple of examples are the type of overhead lines (transmission versus distribution), and the size of water line (12 inches versus 6 feet). • Road Construction This criterion evaluates the complexity, difficulties, and impacts to existing roadways in constructing the alternative. Some examples are roadway horizontal or profile revisions, stormwater or sidewalk reconstruction, and illumination/traffic signals construction or revisions. • Impacts Traffic durin&Construction This criterion evaluates the complexity, difficulties, and impacts to existing traffic in constructing the alternative. Some impact examples are the number of days and hours for lane or roadway closures, the length of detour routes, and the delays for vehicles to reach their destination. Railroad • Railroad Yard Access To and From Freeway This criterion evaluates the complexity or difficulties of vehicle access from the railroad intermodal facility to the freeway and vice versa. Some examples are the distance a vehicle travels from the intermodal facility to the freeway, the number of signalized intersections a vehicle will cross, and the turning movements (i.e., right turns versus left turns). • BNSF Yard Access Reliability This criterion evaluates the complexity, difficulties, and impacts to providing a reliable access to the intermodal facility. The main criterion is the risk associated with an alternative for a closure of a route that restricts access to the facility. This could be due to any reason: bridge closure or collapse, flooding, or road closure. • Impacts to Railroad Operations This criterion evaluates the complexity, difficulties, and impacts to existing intermodal facility operations. Some examples are relocating the check-in/check-out facility, relocating the operations building, vehicle circulations within the facility, or access to storage areas. H.1003 - ProjectsIBNSF accesslSEPAIScreen.ng SummaryIBNSF Intermodai Access Screening summary._2016-1126.docx City of Tukwila 9 Alternative Screening Analysis BNSF Intermodal Facility Access December 2016 Environmental • Air Quality This criterion evaluates the complexity, difficulties, and impacts of air quality. • Noise This criterion evaluates the complexity, difficulties, and impacts of noise to sensitive receivers. • Historic, Cultural, and Archaeological Resources This criterion evaluates the complexity, difficulties, and impacts on historical structures and to cultural or archaeological sites. • Critical/Sensitive Areas This criterion evaluates the complexity, difficulties, and impacts to critical and sensitive areas. • Geotechnical This criterion evaluates the complexity, difficulties, and impacts of geotechnical items to the construction of the alternative. • Traffic - Operations This criterion evaluates the complexity, difficulties, and impacts of traffic operations due to the alternative. • Permitting This criterion evaluates the complexity, difficulties, and impacts of obtaining permits needed to construct each alternative. Cost The last group in the screening matrix is construction cost. This was included for information purposes only. The construction cost was separated into two groups. The first one, Roadway Construction, represents the cost to construct the roadway improvements, or reconstruction of the existing roadway. The second one, Railroad Yard Construction, represents the cost to construct improvements or reconstruct the intermodal facility. Scoring Methodology A numerical scoring system was used to score each alternative. The scoring range was 1-9 with 1 representing the least difficulty or complexity and 9 representing the most difficulty or complexity. With this system, the preferred alternative will have the lowest total. In addition to a numerical score, a color coding system was implemented in order to provide a quick of the scoring. The colors used were red, yellow, and green. The color assignment for the numerical scores is as follows: H-1003-ProjectslBNSFoocesslSEPAIScreentngSummarylBNSFlntermodalAccessScreeningsummary_2016-1128.docx City of Tukwila 10 Alternative Screening Analysis BNSF Intermodal Facility Access December 2016 Color Green Yellow Red Numerical Score 1 through 3 4 through 6 7 through 9 Description Low Complexity/Difficulty Medium Complexity/Difficulty High Complexity/Difficulty SCORING OF ALTERNATIVES The selection criteria matrix was sent to the City of Tukwila and BNSF Railway in order for them to score, independently, each alternative. David Evans and Associates, Inc. also scored each alternative independently. On July 20, 2016, representatives from City of Tukwila, BNSF Railway, and David Evans and Associates, Inc. met to develop a collaborative score for each alternative. The following figure shows the scoring as a result of this meeting. H:1003 • Pro/ectstBNSFaccesslSEPAIScreening SummaryONSFlnfermodal Access Screening summary 2016-1128.docx City of Tukwila 11 Alternative Screening Analysis BNSF Intermodal Facility Access December 2016 Figure 2 — Selection Criteria Screening Matrix SELECTION CRITERIA MATRIX 1 S (suolliAM) Is03 Farad lelol co. 8 et 6 O) 5 ) pi te co. S2 (suolll®N) Isop uoparwsuop pre), PeoJIRM O 8 to O aa O O s $4.4 (suolll W) Iso3 uoparulsuop A A peoa M cri 0 V $28.9 CI) ? O) to pwoos Ie;oi c a a Environmental Ie1oIGns M M U) BupIIWJad CD ti CO CD co suoperado - nava co N. co to in Ieaiuuaal0O v a Is- N. I+ seamy anplsuasAeopu3 r` N v r- r` saanosaa leol8oloaeyaJy pue'IeJnllnp 'ouolsIN N N co co cc) as1oN ' 10 0) cO n AUIenD JIy co r- to co N Railroad immune N N ("I co suoperado peallea o1 spedwl co o) . .— to AIIIIQellatl ssaaay PleA dSNB 0 v b v v APMaaJd woJJ puv o; S11933V preA peahen co co co v co c .s .i Iu0I3nusuo3 U IP)0311nS cv fI RI FI R uopangsuo3 Bump alpm spedwl o) v co co I- peon c) N o) co 1 uopeaolaa saplapp o) or a N. (0 >w at 4 i 1e101rin9 cii ti):L.fa pue'jl8MMMA 0) 0) CO to CD IeI3JPWW03 0) O) N O) CO lelwaplsaa co 00 0) r• .— 41 a. R E cu Q Airport way S m 0 0) S 124th Street Gateway Drive - North Leg 48th Avenue SE M 1 4-6 Medium Complexity/Difficulty High Complexity/Difficulty 0) ; rV CONCEPTUAL CONSTRUCTION COSTS AND RIGHT-OF-WAY ESTIMATES Conceptual construction costs and right-of-way estimates were determined for each alternative. The construction cost estimates were separated into three categories: roadway construction cost (includes bridge construction), railroad construction cost, and right-of-way acquisition cost. The estimates were by three separate entities. The conceptual roadway construction cost estimates were determined by David Evans and Associates, Inc. (DEA). The railroad costs were determined by BNSF Railway. The right-of-way costs were determined by Abeyta & Associates, a right-of-way specialist, and a subconsultant to DEA. The following table provides the conceptual costs for roadway construction, roadway right-of-way, railroad facilities construction, and railroad right-of-way. Alternative Conceptual Cost Estimate (in millions) Roadway Costs Railroad Costs Roadway Right -of -Way Railroad Right -of -Way Total Airport Way S $14.5—$19.3 $0 $58.5—$78.0 $9.0—$12.0 $98.3 — $109.3 S 112th Street $12.4 — $16.6 $3.6 — $4.8 $47.7 — $63.6 $3.3 — $4.4 $80.5 — $89.4 S 124th Street $18.9 — $25.3 $ 2.7 — $3.6 $0 $0 $26.0 — $28.9 Gateway Drive — North Leg $11.3 — $15.0 $6.2 — $8.3 $0 $0 $21.0 — $23.3 48thAvenueS $10.2—$13.6 $1.7—$2.3 $3.3—$4.4 $0 $18.3—$20.4 CONCEPTUAL PLAN SHEETS For each alternative, plan sheets were created. These plan sheets show the proposed roadway edges and new right-of-way. Intermodal facility new construction is not included in these plans. P.IIITUKA000000130600INFOi0670ReportstBNSF Intermodal Access Screening summary _2016-1126.docx City of Tukwila 13 Alternative Screening Analysis BNSF Intermodal Facility Access 0 0 Appendix A — Alternative Plan Sheets P nTUKA0000001310600INFO10670RepnrtstaNSF Intermadal Access Screonrng summary _2016-1128.docx City of Tukwila Alternative Screening Analysis BNSF Intermodal Facility Access 50 40 30 20 10 a to is Ip 1.50% PVI STA 4+85,01 PVI ELEV: 20.02 K: 95 58 INC: 95 58 to c_x 1 PVI STA: 8+09.78 PVI ELEV- 21,65 K: 49 16 LVC• 73 73 /-- PROPOSED GRADE HIGH P7 STA 7+97 49 HIGH PT ELEV 21.52 ++ toy CA W - EXISTING GRADE 0 GI tU m N 0 ✓ N en ai of 0 0 0 0 0 0 N N 0 Y 0 N • N n as nl O N N rl 1V N 3+00 3+50 4+00 4-50 +GO PE] L.1 WORKS .DEPT_ *ENGINEERING*STREETS *WATER SEWER *PARKS *BUILDING * By Date Deskfled vxv Drawn D.0 Checked IM L Pmj Eng Pm} Dir Field Bk 5130 6+00 6-,DC 7+00 7+50 DAVID EVANS ANO ASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005.3518 Phone 425 510 6500 8* DO 8+50 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN AIRPORT WAY S. ALTERNATIVE 50 40 30 20 10 No. Date Revisions 3 111 PP01 File No Scale AS SHOWN Date O Lt) + r too ff� a VJ W Z • I so = IA 40 • III I-- CO 30 M 20 10 r - 1-00% PN STA. 9+42.04 PN ELEV: 20.32 K: 27.21 LVC. 75.00 LOW PT STA 9+31 75 LOW PT ELEV- 20.56 O1 m ci 176 PN STA: 10+61.05 PVI ELEV; 22.41 K: 33.24 LVC: 75.00 HIGH PT. STA 10+81.93 HIGH PT ELEV; 22.27 N 0( O I0 -0.50R PVI STA: 11+60.13 PV1 ELEV: 21.92 K: 75.00 LVC: 75 00 LOW PT. STS- 11+6013 ri LOW PT ELEV: 22 01 4' m PROPOSED GRADE 0.50% PVI STA: 12+79.12 PVI ELEV: 22 51 K: 50.00 LVC: 75.00 NIGH PT STA: 12+66 62 HIGH PT ELEV 22.39 E%ISTNO GRADE N N 8 N n 0 N N C. N 0 N 0 N Nm N 8+50 9+00 9+50 10+]0 10 50 11+00 11+50 •ENGINEERING•STREETS•WATER•SEWER *PARKS *BUILDING • By Dale Designed Drawn DLO checked MLF NEM Prof Dir Field 8k # DAVID EVANS AND ASSOCIATES INC. 415 -118th Avenue SE Bellevue Washington 98005-3518 Phone: 425.519.6500 12+00 12+50 13+00 13+50 50 40 30 20 10 14+00 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN AIRPORT WAY S. ALTERNATIVE No. Date Revisions L 7 1 1 PPO2 a File No. Scale AS SHOWN Date MATCHLINE STA. 12+00 N 0 0 0 1- W W /=50 /� vi W 40 W (f) 30 20 10 U -1.0016 PN STA- 15+70.13 PVI (LEV: 19.60 K: 50 00 LVC: 75.00 LOW PT STA. 15+82.63 LOW PT E1EV: 19.73 0 50% PROPOSED GRAPE P14 STA: 18+06.13 P ELEV: 20.75 K: 75.00 LVC: 75.00 HIGH PT. STA: 18+00 13 HIGH PT ELEV. 0.66 -0 50% GRADE m N 0 an 10 di 0 d 8 N n 01 N M Oi m o In 0 N 14+00 4 50 15+00 15+50 16+00 •ENGINEERING*STREETS *WATER *SEWER *PARKS *BUILDING * 16*50 17+00 I7+50 By Dale Dorafled VXV Drawn DLO Checked MIS Pic1E19 Proj Dir Field Bk 1# DAVID EVANS AND ASSOCIATES INC. 415 -118th Avenue SE Bellevue Washington 98005-3518 Phone' 425 519 6500 18+00 18+50 19+00 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN AIRPORT WAY S. ALTERNATIVE 50 40 30 20 10 19+50 SEE SHEET PPO4 No Date Revisions 1 1 1 PPO3 F le No Scale AS SHOWN Date 0 + M N IL • a - W I.LI Z V/_) ^ 50 = W 40 U - W 30 2 • 20 10 *0F. Y•.•ll. / ♦0.a .:"�11 i[i!1'iti.11titifitlllfi&lt111/1tlll1t1lMiiiti Rf•...•• I6 ..•.11.1•4.Ial.1... ...I�.. �.1 •...a•r• a .I,r.,l �: o 10 2v w PVI STA. 20+2 .13 PSI ELEV. 19 65 K: 73.47 LVO 75.00 LOW PT STA• 20t19.36 LOW PT MY: 19.75 PRDP0644) CIRADE 0 52X ExIarr Q GRADE II 50 40 30 20 10 0 N a m cn n 0 n N 0 N d O N N m 19+5D 20+00 20+50 21+00 2'+50 22+00 22+50 PUBLIC' WORKS *ENGINEERING*STREETS *WATER *SEWER PARKS *BUILDING • Designed Drawn Checked Proj Eng Proj Dir FielBkIF By Date Date VXV 1* 23+00 23+50 DAVID EVANS AND ASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone: 425.519 6500 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN AIRPORT WAY S. ALTERNATIVE L J ■ 3 1 1 1 1 PP04 of File No Scale AS SHOWN No Date Revisions Date 50 40 30 20 10 02 O 0 ai m r� c 0.501 PROPOSED GRADE 8 8 r Qi a m $ $ at at PVI STA: PVI ELEV. 19.93 It, 43.88 LVC: 175.00 5+09.96 HIGH PT S1A: 4+94.40 RICH PT ELEV: /9.80 a. $ 0 a 1+00 r+50 2+00 2+50 3+00 3+50 4+00 4+50 5+00 PUB.1IC WORKS .DAP r *ENGINEERING*STREETS*WATER *SEWER PARKS *BUILDING * By Date Desipnad vxv Drawn OLO Checked les Pal Eng Prof Dir Field Bk DAVID EVANS ANoASSOC' ATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone: 425 519.6500 w .0 EXISEING GRADE 8 N m 5+50 6+00 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN S. 112TH ST. ALTERNATIVE 0 CO 0 Q 0- I"-H to W LU Z 2 1 .71. • 2w w ■ 50 40 30 20 10 1 1 0 Lo I- CNI CD 0 0- I— l2 CO I.LI w Z 2 -i J co 2o w w I— Li Q 2 No. Dale Revisions PP01 File No. Sae AS SHOWN Date 50 40 30 20 10 LT b 0 '0 N 0 m PN STA! 9+64.10 PV1 ELEV: 1'4.44 K: 112.50 LVC- 75.00 w _0.541 0f m b r os O 0 eel 1~O ^ N 14 e7 e'f 6+00 6+50 7.00 7+ 50 8+00 8+50 9+00 9+50 10+00 '0+50 P Z.jBLIC WORKS CEP y *ENGINEERING*STREETS *WATER SEWER *PARKS *BUILDING * By Dale Designed Vxv Drawn DLO Checked MLF Nei Eng Prof Dr Field Bk # DAVID EVANS AND ASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone: 425.519 650 D BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN S. 112TH ST. ALTERNATIVE 11+00 11+50 50 7 1 1 1 O + III C‘I mil co < CO W II W Z ■ u) 40 IllUW 30 }'� (f) 20 10 No. Date Revisions PPO2 Fife No. Scale AS SHOWN Date O O + (NJ N O r a LQ 0L I- I- to III Z = 50 _7 w 40 2 C 30 20 G 10 O 10 00 +o- 4 Pv1 STA: 13+29.63 P VI (LEV: 12.46 K: 98 06 1110 i20 00 LOW PT. STA: 13+22.82 LOW PT ELEV: 12.64 PROPOSED GRADE 0 68% PN STA. 16+72 72 PV1 ELEV. 14.80 K: ' 123.51 LVC! 150.00 EVCS 17+47 72 b lV N 10 m co N r 3 N n 8 8 n n N vt 12+00 12+51] 13+00 13+50 14+00 *ENGINEERING*STREETS *WATER *SEWER *PARKS BUILDING * By Dale Designed Drawn DLO Checked MLF Rini Eng Pmj Dir Field Bk 14+50 +5+00 15+50 16+00 16+50 17+00 DAVID EVANS AND ASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone: 425 519.6500 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN S. 112TH ST. ALTERNATIVE 17+50 50 40 30 20 10 No, Date Revisions PP03 01 Fie No, Scale AS SHOWN Date f I I M111/111155:' n r O u) + M O a_ (O W Z = 50 J W 40 ( 30 G 20 10 0 02 20 10 n h PROPOSED ORADE m 04 tO 0to - N m A 0' 17+50 16+00 18+50 19+00 19+50 *ENGINEERING*STREETS WATER *SEWER *PARKS *BUILDING By Dale Desired VXV Drawn DLO Checked Alf ProlEng Proj Dir Field Bk 50 40 30 20 10 DAVID EVANS AND ASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone: 425.519.6500 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN S. 112TH ST. ALTERNATIVE 1 J 7 1 1 1 1 PPO4 File No w Scale AS SHOWN No Date Revisions Date 1- 2 z- J w 2 > U0 << Mw w PLJBI.IC WORKS 3f3.E1='7" _ 'ENGINEERING *STREETS *WATER *SEWER PARKS *BUILDING * By Date Designal VXV Drawn Checked DLO MLF Rai Eng Raj Dir ;Field Bk # DAVID EVANS AND ASSOCIATES INC. 415 - 118th Avenue SE Bel evue Washington 98005-3518 Phone: 425 519 6500 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN S. 124TH ST. ALTERNATIVE 0 +0 20 • 1 PP01 Fete No Scale AS SHOWN No, Date Revisions Date 50 40 30 20 10 MATCHLINE SEE SHEET PPO1 1 E1 n4°NCk aliAOE 0 10 20 13 8 N A e o' N N i n e H m N 8 N N 8 I+00 ++50 2+00 2+50 3400 3+50 ++00 4+50 5+00 5+50 6+00 50 40 30 20 10 L 3 1 1 0 coo a Ia cow w ww z 2 III, J CO = W 111 2 WOR.JKS DEPT_ *ENGINEERING *STREETS *WATER *SEWER PARKS *BUILDING * 1900 BY Date Desiined Drawn DLO Checked MLF Pioi En9 Plot Dir Field !Rd DAVID EVANS AND ASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone: 425 519 6500 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN S. 124TH ST. ALTERNATIVE No. Date Revisions 1 PPO2 File No. Scale AS SHOWN Dale An 1 0 {c a. co cow Z= = w Hw • ci) 0 co Q t� co ww Z = so J CO = w 40 • w Q cf) 30 • 20 10 O 10 20 exlsrNO GRADE 8 14 8 N G N • ry 8 O G N N N 6+00 6+50 7+00 7+50 a+00 _Pjj ii,ic WAR S KEPT_ *ENGINEERING*STREETS*WATER *SEWER PARKS *BUILDING • 6+50 9+00 By Date Designed vkv Drawn DLO Checked MLF Pkoj Eng P1oj Dir Field Bk # DAVID EVANS AND ASSOC IATES. INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone- 425.519,6500 6+50 10+00 10-50 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN S. 124TH ST. ALTERNATIVE 11+00 1•+5❑ 50 40 30 20 10 No. Date Revisions l 7 • 1 1 PPO3 a File No Soak AS SHOWN Date 0 + M 0 a_ co Qa 1—I— cow w= Z ▪ III= w U � I- 0 + ca) • eL '0 r~w n w Z150 = 40 CO• LU 30 • 20 10 5 03 20 ae n a a n Sft9TfJf10RADE N N N 11+50 12+00 12+50 12+00 13+50 By Date • ENGINEERING *STREETS *WATER *SEWER PARKS *BUILDING * Designed vxv Drawn DLO Checked MLF Pm'Eng Pmj Dir Feld Bit # 14+00 11 50 15+00 15+50 16+00 16+50 17+00 DAVID EVANS Q AND ASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone: 425.519 6500 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN S. 124TH ST. ALTERNATIVE 50 40 30 20 10 0 0 + 1•-•0 eL HI- �w Z� J w w UU) 1 1 ■ ■ ■ 1 PPO4 d Fite No. Scale AS SHOWN No. Date Revisions Date 1 O O + d' � O Qa co w Z� 50 • W 40 • W I— U) 30 • 20 10 O 10 20 40 EXi97140 GRADE 0 N 01 8 m s 5 0 5 17+00 17+50 18+00 18+50 19+00 *ENGINEERING*STREETS *WATER *SEWER *PARKS *BUILDING * By Dale Desired vkv Drawn OLO Checked MLF Prof Eng P10 Dir Field Bk 19+50 20+00 DAVID EVANS AND ASSOCIATES INC. 415 -118th Avenue SE Bellevue Washington 98005-3518 Phone: 425.519.8500 20+50 21+00 +50 22+00 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN S. 124TH ST. ALTERNATIVE 22+50 50 40 30 20 10 L 1 1 O ■ 11') + {p N O ■ N aa. II U) W W w z=al J co = W UW I— (/) a M PP05 File No Scale AS SHOWN No Date Revisions Date A I 1 0 to CV N 0 CNI cL nW Z ( 50 • 40 UIll () 30 • 20 10 TA- 22+50 23+00 /EXSThQGRADE S W 8 at i1] 23+50 24+00 24+50 25+00 25+50 U�3L�C WORKS DEFT_ •ENGINEERING*STREETS *WATER *SEWER PARKS *BUILDING * BY Data Desved Drawn VXV DLO Checked MLF Prof Eng ROD* Field Bk # DAVID EVANS AND ASSOCIATES INC. 415 -118th Avenue SE Bellevue Washington 98005-3518 Phone. 425.519 6500 26+00 26+50 50 40 30 20 10 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN S. 124TH ST. ALTERNATIVE L 7 • 1 1 ■ ■ 1 PPD6 at File No Scale AS SHOWN No Date Revisions Dale 0 10 20 *0 MATCHLINE STA. 7+50 SEE SHEET PPO2 CALL 48 HOURS BEFORE YOU DIG COMMON GROUND ALLIANCE 811 f�1 GRADE 0, 0, ea n 2+.u. 2-5C 3 0•0 3+50 4+00 +50 * ENGINEERING *STREETS *WATER •SEWER *PARKS *BUILDING * 5+00 5+50 8+00 6+54 7+00 7+50 By Date Desired Drawn OL0 Checked MLF Proj Eng Prof Dir Field Bk # DAVID EVANS AND ASSOCIATES inc. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone. 425 519.6500 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN GATEWAY DRIVE ALTERNATIVE 50 40 30 20 10 MATCHLINE STA. 7+50 SEE SHEET PPO2 L 1 J 1 1 1 PP01 w 1 File No Scae AS SHOWN No. Date Revisions Date l 1 0 +� ty <0 �W ww _z N so J = w 40 (/) 30 2 20 io EXEMNO OFlADE 0 8 Oa .11 0 7r50 11- 00 y.. 50 9+00 9+50 *ENGINEERING*STREETS *WATER *SEWER *PARKS *BUILDING * By Date Disbanad vxv Drawn 0l0 Checked wu PmiEng Pmj 0v Field Bk 10+00 ' 0+ 50 DAVID EVANS ANoASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone: 425 519.6500 11+00 +1+ 50 +00 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN GATEWAY DRIVE ALTERNATIVE 12+50 50 40 30 20 10 13+00 No Dale Revisions SEE SHEET PPO3 1 J • J 1 1 1 PPO2 d File No Scale AS SHOWN Dale 1 n MD CONSTRUCTPEW CTAY a a 29 .o + CJ C) a ij w 50 W Z = 40 • W 30 • 20 2 10 d n EXISTNa GRADE d ut N + . 11 01 N PV1 STA. 17+68.96 PV1 ELEV; 22.09 K. 38.18 LVC 85.00 10 N N 13+00 13+50 14+00 14+50 15+00 ENGINEERING *STREETS *WATER *SEWER *PARKS *BUILDING * BY Dale Drawn OLO Checked ML N Enp Field Bk # 15+50 16+00 16+50 17+00 174.50 DAVID EVANS AND ASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone- 425.519.6500 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN GATEWAY DRIVE ALTERNATIVE 18+00 l 3 0 M+ W • a Q El- m CO 111 W a0Z= it 30 W UW ♦- co 10 20 18+50 No, Date Revisions PPO3 a F•le No Scale AS SHOWN Dale 0 11) } M c0 0 Q 0 (/) LJJ 50 Z 40 ▪ W 30 �W U)20 • 10 5.00% PN STA: 19+67.10 PN ELEV: 32.00 K: 17.78 LVC: 80.00 2' SLAB DEPTH BEGIN PEDESTRIAN TRAIL END PEDESTRIAN 'TAIL 0 n 0 Vl 0 n U W 8 5' GIRDER DEPTH PATH ADDED 10" TO ACOMMODATE 4% SUPERELEVATED STRUCTURE *ASSUME 38' WIDE BRIDGE WITH 4% SUPER ELEVATION 0.50% PN STA: 21t95.10 PN ELEV: 3314 K: 1727 LVC: 95.00 o0 e n UN W m 0 HIGH PT STA: 21+56.23 ICH PT ELEV• 32.92 * li BASE FL000 ELEVATION-16' J o +0 10 PROPOSED GRADE —3.00x EXERNIG GRADE 30 BEGIN 5 121 N 0 — (3 .0 n CI n N n 40 20 10 0 0 N 15.50 19+00 19+50 20+00 20+50 *ENGINEERING*STREETS*WATER*SEWER*PARKS *BUILDING * 21+00 21+50 22+00 22+50 23+00 By Date Designed V)V Drawn DLO Checked MLF Raj Eng Prof Dir Field Bk X DAVID EVANS AND ASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone: 425.519 6500 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN GATEWAY DRIVE ALTERNATIVE 23+50 24+00 No. Date Revisions 1 1 PPO4 or Fie Na. Scale AS SHOWN Date 5 5 7 0 O a. a I- W W w W 0 50 40 N Q 30 Cr) 20 Z 10 J U 5� P L � PVI STA; 24+22.11 PN ELEV: 21.79 K: 37 57 LVC: 120.00 H 5T EJ(IBTNd ORADE N N tri r 8 b J N 8 N 24+00 24+50 25+00 25+50 26+00 25+52 27+20 27+50 28+00 28+50 29+00 29+50 P UBLIC WORKS DEPT. • ENGINEERING *STREETS *WATER *SEWER PARKS *BUILDING * By Dale Designed Vxv Drawn OL0 Checked .tF Pmj Eno Pmj DU Field Bk DAVID EVANS ANDASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone 425.519.8500 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN GATEWAY DRIVE ALTERNATIVE 1 1 ■ ■ 50 II 40 30 20 10 30+00 PPO5 Fie No. Scale AS SHOWN No. Date Revisions Date 50 40 30 20 10 0 0 10 20 40 EXISTING GRADE 1 m m 0 8 m 8 m 8 1+00 1+50 2+00 2+50 3+00 *ENGINEERING*STREETS *WATER *SEWER *PARKS *BUILDING * By Date oesioned Drawn 0L0 Checked MLF Proj Eng Prof Dir field Bk ft 3+50 4+50 DAVID EVANS AND ASSOCIATES INC. 415 -118th Avenue SE Bellevue Washington 98005-3518 Phone: 425.519 6500 5+i7C 5+50 8+00 a+50 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN 48TH AVE. S. ALTERNATIVE MATCHLINE STA. 6+50 50 40 30 20 10 0 SEE SHEET PPO2 MATCHLINE STA. 6+50 No. Date Revisions SEE SHEET PPO2 1 J 1 1 1 PP41 of I I E 0 Lf) + CO . d Q� I- 1- Uw Z 2 J LLJ HLLI U) 0 Lf) + co 0 <a CO w 50 ww Z 2 40 J = w 30 I- ILI CO 20 10 0 6+50 7+00 7+50 8+00 5+50 5+00 1111ZJ1LIC WORKS DEBT_ *ENGINEERING*STREETS *WATER *SEWER *PARKS *BUILDING * By Date Designed vxv Drawn DLO Checked MLF Pill Eng Ptal Dir FeldBk# 9+50 10+00 10+50 11+00 t1+50 12+00 DAVID EVANS AND ASSOCIATES mac. 415 - 118th Avenue SE Bellevue Washington 98005.3518 Phone: 425.519 6500 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN 48TH AVE. S. ALTERNATIVE 7 1 1 1 0 ■ 0 + M ■ N ra a so c~n w z▪ ci) 30 1-1-1 w zo U) to 2 40 0 PPO2 Fite No a Scale AS SHOWN No. Date Revisions Date 0 O + N N O r d IA 50 Z 40 7 w 30 w C° 20 10 0 0 0 70 40 EX1NG GRADE S 01 8 01 m 01 4 01 8 0 8 0 8 8 8 8 0 2+00 12+50 3+00 13+50 14+00 *ENGINEERING *STREETS *WATER *SEWER *PARKS *BUILDING By Date Designed vxv Drawn DLO Checked MLF Prof Eng Prof Dir Field Bk 14+50 t5+00 70F DAVID EVANS AND ASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone: 425.519.6500 5t50 16+00 16+50 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN 48TH AVE. S. ALTERNATIVE 17+00 7+50 MATCHLINE STA. 17+50 50 40 30 20 10 0 No, Date Revisals SEE SHEET PP04 L PP03 File No SCAM AS SHOWN Date 0 + M N. �a I- I— �w W= zC° W = W U� 2 0 td) + M I- a I— t2 fA W z =W 50 ▪ W 40 = Wu) 30 • 20 10 0 Y ROADWAY AND CONSIAUCT IMPROYMENTS O 10 20 40 0 051c PVI STA: 19+15 58 PVT ELEN 19 96 K: 26.72 LVC: 135.00 LOW PT STA: 18+49 50 LOW PT ELEN 20 00 DRIVEWA RT (FILL 32') DRIVEWAY LT (FILL 2 51 to 01 0 •ASSUu£ 38' WIDE BRIDGE W1114 411 SUPER ELEVATION FINISHED GRADE E IBTNO GRADE 5008 7' SLAB DEPTH 01 N PN STA 21+77 32 PVI ELM 33.05 K 12,28 LVc: 70.00 8.5' GIRDER DEPTH WITH ADDED 10' TO ACOULIOOATE-4x SUPEREL£VATEO STRUCTURE HIGH PT STA: 22+03.70 HIGH PT ELEV: 32 83 -a T BEGIN PEDESTRIAN TRAIL E015LR AE0€SW(AN- TRAIL ENO PEDESTRIAN TRA L O#st 1w00 T Evw-nOrorT'r"----1 N 0 CO NN a m N CO 40O p N N m N m N e4 :.I 17r50 18+00 18+50 19+00 19+50 I' ZJBLdIc WOIKS • ENGINEERING*STREETS *WATER *SEWER PARKS *BUILDING By Data Designed Vxv Drawn DLO Checked ALF Prof Enp Proj 0ir Field Bk 20+00 20+50 21+00 21+50 22+00 DAVID EVANS AND ASSOCIATES INC. 415 -118th Avenue SE Bellevue Washington 98005-3518 Phone 425.519.6500 22+50 23+00 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN 48TH AVE. S. ALTERNATIVE 50 40 30 20 10 0 No, Date Revisions 1 • 3 1 0 M 0 N d )-- CD W W z co= ■l J_ W W U� Q M PPO4 File No Scale AS SHOWN Date 0 0 �o N d �a 1- (nW WW ZI J = W UW I- C/3 O O + q. M O N d () I j 60 ZW 7.1 //Y_�� 50 / W 40 (n 30 G 20 10 0 RAISE ROADWAY PROFLE FOAMS IN -PLACE PVI, STA: 24+20.06 OV ELEV: 31.35 K: 139.32 LVC: 75 00 re m PROPOSED GRADE -1 247t 1 8ECIN RAILROAD AVE(FILL 9.4') EWING GRADE A 23+00 23150 24+00 24+50 60 50 40 30 20 10 0 25+00 25+50 26+00 26+50 I'L7I3L Ic WORKS DEIST_ *ENGINEERING*STREETS *WATER *SEWER *PARKS *BUILDING * By Date Designed Drawn VXV DLO Checked 6YF Nei Eng Pmj Dir Field Bk # DAVID EVANS AND ASSOCIATES INC. 415 - 118th Avenue SE Bellevue Washington 98005-3518 Phone. 425 519 8500 10 70 10 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN 48TH AVE. S. ALTERNATIVE No. Date Revisions L 1 1 ■ ■ 1 ■ 1 PPO5 d File N Scala AS SHOWN Date Appendix B — Truck Access Routes P:IIITUKA00000013106001NFO10670ReportslBNSF Inlermodal Access Screening summary_2016-1128 docx City of Tukwila Alternative Screening Analysis BNSF Intermodal Facility Access November 28, 2016 • Z�BL�C' WORDS I.AEPT_ •ENGINEERING+STREETS •WATER *SEWER PARKS *BUILDING • Designed Drawn • Checked PEng P10101 Field Bk # By V%V 01A MLF Date 10115 10115 '10115 DAVID EVANS AND ASSOCIATES INC. 415 - 1181h Avenue SE Bellevue Washington 98005-3518 Phone: 425.519.6500 LEGEND • 0 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN 48TH AVE. S TRUCK ACCESS TO FREEWAY No. Dale NOT TO SCALE ROUTE: FREEWAY TO BNSF YARD (0.5 MILE) ROUTE: BNSF YARD TO FREEWAY (0.5 MILE) TRAFFIC SIGNAL Revisions a He No. L J • ■ 3 0 • 1 Scale AS SHOWN Dale S 124TH STREET ALTERNATIVE S 133RD ST f BNSF YARD LEGEND a PUBLIC WORKS DEFT. •ENGINEERING •STREETS •WATER •SEWER *PARKS *BUILDING • Designed Drawn Checked By Date VXV DLO 10115 10115 10t15 Pro' En0 Pros Dir Field Bk M DAVID EVANS ANDASSOCIATES INC. 415 - 11 Bth Avenue SE Bellevue Washington 98005-3518 Phone: 425.519.6500 BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN S. 124TH ST. TRUCK ACCESS TO FREEWAY NOT TO SCALE ROUTE: FREEWAY TO BNSF YARD (1.3 MILE) ROUTE: BNSF YARD TO FREEWAY (1.3 MILE) TRAFFIC SIGNAL No, Date Revisions L 3 • 1 File No. Scale AS SHOWN Date r PUBLIC' Wc3RKS DEPT_ •ENGINEERING •STREETS •WATER •SEWER *PARKS *BUILDING • Designed Draw Checked Pra3 En PM dr Field Bk # vxv DLO MLF By Dale 10415 10115 10115 DAVID EVANS AND ASSOCIATES Inc. 415 -118th Avenue SE Bellevue Washington 96005.3518 Phone: 425.519.8500 LEGEND • BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN GATEWAY DR. TRUCK ACCESS TO FREEWAY NOT TO SCALE ROUTE: FREEWAY TO BNSF YARD (0.9 MILE) ROUTE: BNSF YARD TO FREEWAY (0.9 MILE) TRAFFIC SIGNAL No. Date Revisions L 3 1 1 • or 1 File No. Scale AS SHOWN Dale g BOEINQ ACCESS RD AIRPORT WAY S ALTERNATIVE • ' BNSF • YARD *ENGINEERING*STREETS*WATER *SEWER *PARKS *BUILDING Detipntd. By vxv Drawn DLO Checked MLF Dale 1nr15 1a15 1a1e Nei EN Proj Dir Field Bk # DAVID EVANS AND ASSOCIATES INC. 415 - 1181h Avenue SE Bellevue Washington 98005-3518 Phone: 425.519.6500 LEGEND i BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN AIRPORT WAY S. TRUCK ACCESS TO FREEWAY NOT TO SCALE L ROUTE: FREEWAY TO BNSF YARD 0.4 MILE) ROUTE: BNSF YARD TO FREEWAY 0.4 MILE) TRAFFIC SIGNAL I d Rio No. Soae AS SHOWN No. Date Revisions Date Appendix C — Roadway Cost Estimate Back-up P:IATl1KA00000013i06001NF010870RopatstBNSF Inteimodal Access Screening summary _2016.1128 docx City of Tukwila Alternative Screening Analysis BNSF Intermodal Facility Access November 28, 2016 City of Tukwila BNSF Intermodal Access Study Planning Level Cost Estimate Alternate: Location: Length: Description: Assumptions: Airport Way S Airport Way S to BNSF Intermodal Facility 1800' CI DAVID EVANS ANo ASSOCIATES INC. Date: Prepared by: Checked by: 11/28/16 MLF Alternative uses Airport Way S to northem end of BNSF yard. See alternative exhibit Existing Widths: Proposed Widths: Pavement Varies 40' to 52' Pavement 44' Preparation 1 Mobilization $772,900.00 2-4 Preparation Items $164,500 00 5-12 Removal Items $82,000.00 Preparation Subtotal $1,019,400.00 Grading 13-14 Roadway Grading 15-18 Roadway Foundation 19-24 Utility Excavation Grading Subtotal $112,548.00 $150,275.00 $20,400.00 $283,223,00 Storm Drainage 25-36 Conveyance System 37 Culvert/Stream Crossing 38 Detention/Water Quality Facility Storm Drainage Subtotal $188,500.00 $0.00 $0.00 $188,500.00 Hot Mix Asphalt Pavement 39-42 Hot Mix Asphalt Pavement $146,850.00 HMA Subtotal $146,850.00 Concrete 43-44 Sidewalks and Driveways 45-46 Curbs and Gutters 47 Concrete Roadway Concrete Subtotal $100,345.00 $64,500.00 $0.00 $164,845.00 Sidewalk 0 Sidewalk 6' both sides Right -of -Way Varies 60' to 80' Right -of -Way 67' Structures 48-51 Retaining Walls 52 Bridge Structure Structure Subtotal $71,860,00 $6,160,000.00 TESC and Landscaping r 53-55 TESC 56-60 Plantings 61-62 Irrigation TESC and Landscaping Subtotal Traffic $6,231,860.00 $53,200.00 $105,000.00 $0.00 J $158,200.00 63-71 72-75 76-80 81-83 84-89 Markings and Signing Guardrail/Handrail Traffic Signal System Illumination System Traffic Control Traffic Subtotal $5,884.00 $0.00 $170,000.00 $75,000 00 $50,000.00 $300,884.00 Other Items 90.91 Utility Relocates 92-94 Misc. Construction Other Items Subtotal CONSTRUCTION SUBTOTAL CONTINGENCY CONSTRUCTION SUBTOTAL (a) 30% DESIGN ENGINEERING 18% CONSTRUCTION ENGINEERING 12% PROJECT ADMINISTRATION 5% ENGR. AND ADMIN. SUBTOTAL (b) ENVIRONMENTAL ENGINEERING 5% ENVIRONMENTAL MITIGATION 5% ENVIRONMENTAL SUBTOTAL (c) $0.00 $22,200.00 $22,200.00 $8,515,962 $2,554,790 $11,070,752 $1,992,740 $1,328,500 $553,540 $3,874,780 $553,540 $553,540 $1,107,080 ROADWAY IMPROVEMENTS (a+b+c) ROADWAY RIGHT-OF-WAY ROADWAY SUBTOTAL MARKET CONTIGENCY ROADWAY TOTAL (d) 20% $16,050,000 $0 $16,050,000 $3,210,000 $19,260,000 RAILROAD IMPROVEMENTS RAILROAD RIGHT-OF-WAY RAILROAD SUBTOTAL MARKET CONTIGENCY RAILROAD TOTAL (e) 20% $65,000,000 $10,000,000 $75,000,000 $15,000,000 S90,000,000 TOTAL PROJECT COST (d+e) (Year 2016) $109,300,000 Page 1 of 1 Printed: 11/2812016 P 111TUKA00000013W600INF010650Des gnOocs10653Es1 males101 _BNSF Access Cost Est A,rportx.s S 112TH ST ALTERNATIVE PUBLIC WORKS D.EP T. •ENGINEERING •STREETS *WATER *SEWER *PARKS *BUILDING * By Date Clestrled Draw Checked Pm) Erg Prof Dlr Field Bk A vxv DLO MLF 10115- 10115 10115 DAVID EVANS ANDASSOCIATES Inc. 415 - 11861 Avenue SE Bellevue Washington 98005.351E Phone: 425.519.6500 LEGEND BNSF INTERNATIONAL FACILITY ACCESS PROJECT ALTERNATIVE CONCEPTUAL DESIGN S. 112TH ST TRUCK ACCESS TO FREEWAY NOT TO SCALE ROUTE: FREEWAY TO BNSF YARD (1.1 MILE) ROUTE: BNSF YARD TO FREEWAY (1.1 MILE) TRAFFIC SIGNAL L 3 1 1 File No d Scale AS SHOWN No. Date Revisions Date City of Tukwila BNSF Intermodal Access Study Planning Level Cost Estimate ,iternate: Location: Length: Description: Assumptions: South 112th Street East Marginal Way to BNSF Intermodal Facility 1750' CI DAVID EVANS ANDASSOCIATES INC. Date: Prepared by: Checked by: 11/28/16 MLF Alternative uses utility corridor and ties into the northern half of BNSF yard see alternative exhibit Existing Widths: Proposed Widths: Pavement Varies 40' to 52' Pavement 44' Preparation Mobilization 2-4 Preparation Items 5-12 Removal Items Preparation Subtotal $276,700.00 $91,600.00 $30,450.00 Grading 13-15 Roadway Grading 16-19 Roadway Foundation 20-25 Utility Excavation Grading Subtotal $398,750.00 $96,889,00 $122,325.00 $16,640.00 $235,854.00 Storm Drainage 26-37 Conveyance System $149,850.00 38 Culvert/Stream Crossing $0.00 39 DetentionlWater Quality Facility $1,500,000.00 Storm Drainage Subtotal $1,649,850,00 Hot Mix Asphalt Pavement 40-43 Hot Mix Asphalt Pavement $118,800.00 HMA Subtotal Concrete 44-45 Sidewalks and Dnveways 46 47 Curbs and Gutters 48 Concrete Roadway Concrete Subtotal $118,800.00 $81,690.00 $52, 500.00 $0.00 $134,190.00 Sidewalk 0 Sidewalk 6' both sides Right -of -Way Varies 60' to 80' Right -of -Way 67' Structures 49-52 Reta ning Walls 53 Bridge Structure Structure Subtotal $0.00 $0.00 $0 00 TESC and Landscaping 1 54-56 TESC 57-61 Plantings 62-63 Irrigation TESC and Landscaping Subtotal $46,400.00 $84,890.00 $32,400.00 $163,690.00 Traffic 64-72 73-76 77-81 82-84 85-90 Markings and Signing Guardrail/Handrail Traffic Signal System Illumination System Traffic Control Traffic Subtotal $5,084.00 $0.00 $170,000.00 $150,000.00 $30,000.00 $355.084.00 Other Items 1 91-92 Utility Relocates 93 95 Misc. Construction Other Items Subtotal CONSTRUCTION SUBTOTAL CONTINGENCY CONSTRUCTION SUBTOTAL DESIGN ENGINEERING CONSTRUCTION ENGINEERING PROJECT ADMINISTRATION ENGR. AND ADMIN. SUBTOTAL 30% 18% 12% 5% ENVIRONMENTAL ENGINEERING 10% ENVIRONMENTAL MITIGATION 5% ENVIRONMENTAL SUBTOTAL $4,000,000.00 $29,000.00 $4.029,000.00 $7,085,218.00 $2,125.570.00 $9,210,788.00 $1,657,950.00 $1,105,300.00 $460,540.00 $3,223,790.00 $921,080.00 $460,540.00 $1,381,620.00 ROADWAY IMPROVEMENTS (a+b+c) ROADWAY RIGHT-OF-WAY ROADWAY SUBTOTAL MARKET CONTIGENCY ROADWAY TOTAL (d) 20% $13,820,000 $4,000,000 $17,820,000 $3,560,000 $21,360,000 RAILROAD IMPROVEMENTS RAILROAD RIGHT-OF-WAY RAILROAD SUBTOTAL MARKET CONTIGENCY RAILROAD TOTAL (e) 20% $53,000,000 $3,700,000 $56,700,000 $11,340,000 $66,040,000 TOTAL PROJECT COST fd+e) (Year 2016) $89,400,000 P ihTUKA0000001310600INF010650DesignDocs10653Estimates102 BNSF Access Cost Est 112th x 5 Page 1 of 1 Printed: 11/28/2016 City of Tukwila BNSF Intermodal Access Study Planning Level Cost Estimate .Iternate: Location: Length: Description: Assumptions: S 124th Street Interurban Avenue S to BNSF Intermodal Facility 3400' Q DAVID EVANS ANDASSOCIATES INC. Date: Prepared by: Checked by: 11/28/16 MLF Alternative uses 42nd Avenue S, over Duwamish River, right on S 124th Street, and into the existing BNSF yard access. Improvements along the existing route must be made, i.e. pavement rehabilitation, replacement of bridge over Duwamish River. See alternative exhibit Existing Widths: Proposed Widths: Pavement Vanes 40' to 52' Pavement 44' Preparation 1 Mobilization $937,800.00 2-4 Preparation Items $154,400.00 5-12 Removal Items $121,228.00 Preparation Subtotal $1,213,428.00 Grading 13-14 Roadway Grading 15-17 Roadway Foundation 18-23 Utility Excavation Grading Subtotal $0 00 $0.00 $0.00 $0.00 Storm Drainage 24-35 Conveyance System 36 Culvert/Stream Crossing 37 Detention/Water Quality Facility Storm Drainage Subtotal $65,200,00 $0.00 $75,000,00 $140,200.00 Hot Mix Asphalt Pavement 38-41 Hot Mix Asphalt Pavement HMA Subtotal $311,500.00 1 Concrete 42-43 Sidewalks and Driveways 44-45 Curbs and Gutters 46 Concrete Roadway Concrete Subtotal $311,500.00 $44,000.00 $66,300.00 $0 00 $110,300.00 Sidewalk 0 Sidewalk 6' both sides Right -of -Way Varies 60'to 80' Right -of -Way 67' 1 Stluistures 47-52 Retaining Walls 53 Bridge Structure $4,811,400.00 $2,745,600 00 Structure Subtotal $7,557,000.00 TESC and Landscaping 1 54-56 TESC 57-61 Plantings 62-63 Irrigation TESC and Landscaping Subtotal $256,200.00 $86,860.00 $13,500.00 $356, 560.00 1 Traffic 64-72 73-76 77-81 82-84 85-90 Markings and Signing Guardrai /Handrail Traffic Signal System Illuminafon System Traffic Control Traffic Subtotal $17,680.00 $73, 500.00 $180,000.00 $125,000.00 $250,000.00 $646,180.00 Other Items 1 91-92 Utility Relocates 93-95 Misc. Construction Other Items Subtotal CONSTRUCTION SUBTOTAL CONTINGENCY CONSTRUCTION SUBTOTAL DESIGN ENGINEERING CONSTRUCTION ENGINEERING PROJECT ADMINISTRATION ENGR. AND ADMIN. SUBTOTAL 30% 18% 12% 5% ENVIRONMENTAL ENGINEERING 10% ENVIRONMENTAL MITIGATION 10% ENVIRONMENTAL SUBTOTAL $100.000.00 $33,200.00 $133,200.00 $10,468,368 00 $3,140,520.00 $13,608,888.00 $2,449,600.00 $1,633,070.00 $680,450.00 $4,763,120.00 $1, 360,890.00 $1,360,890.00 $2,721,780.00 ROADWAY IMPROVEMENTS (a+b+c) ROADWAY RIGHT-OF-WAY ROADWAY SUBTOTAL MARKET CONTIGENCY ROADWAY TOTAL (d) 20% $21,090,000 $3,000,000 $24,090,000 $4.820,000 $28,910,000 RAILROAD IMPROVEMENTS RAILROAD RIGHT-OF-WAY RAILROAD SUBTOTAL MARKET CONTIGENCY RAILROAD TOTAL le) 20% $0 $0 $0 $0 $0 TOTAL PROJECT COST,d+ejlYear 20161 $28,900,000 Page 1 of 1 Printed: 11/28/2016 P 111TUKA0000001310600INF010650DasignDocs10653Estimales103_8NSF Access Cost Est 124lh xis City of Tukwila BNSF Intermodal Access Study Planning Level Cost Estimate Jternate: Location: Length: Description: Assumptions: Gateway Drive - North Lem Interurban Avenue S to BNSF Intermodal Facility 2700' Cif DAVID EVANS ANDASSOCIATES INC. Date: Prepared by: Checked by: 11/28/16 MLF Altemalve uses north leg of Gateway Drive, goes between the two Boeing Credit Union Building, over Duwamish River, and Into the existing BNSF yard access. See altemative exhibit Existing Widths: Proposed Widths: Pavement Vanes 40' to 52' Pavement 44' Preparation 1 Mobilization 2-4 Preparation Items 5-12 Removal Items Preparation Subtotal $567,600.00 $115,000.00 $50,342.00 Grading 13-14 Roadway Grading 15-19 Roadway Foundation 20-25 Utility Excavation Grading Subtotal $732,942 00 $28,995.00 $263,004.00 $4,960.00 $296,959.00 Storm Drainage 26-37 Conveyance System $62,200.00 38 Culvert/Stream Crossing $0.00 39 Detention/Water Quality Facility $1,000,000.00 Storm Drainage Subtotal $1,062,200.00 Hot Mix Asphalt Pavement 40-46 Hot Mix Asphalt Pavement HMA Subtotal $207,675.00 Concrete 47-48 Sidewalks and Driveways 49-50 Curbs and Gutters 51 Concrete Roadway Concrete Subtotal $207,675.00 $119,145.60 $66,300.00 $0.00 $185,445.00 Sidewalk 0 Sidewalk 6' both sides Right -of -Way Varies 60'to 80' Right -of -Way 67' Structures 52-57 Retaining Walls 58 Bridge Structure $245,250.00 $2,481,600.00 Structure Subtotal $2,726,850.00 f TESC and Landscaping J 59-61 TESC 62-66 Plantings 67-68 Irrigation TESC and Landscaping Subtotal $256,200.00 $156,720.00 $52, 380.00 $465,300.00 Traffic 69-77 78-81 82-86 87-89 90-95 Markings and Signing Guardrail/Handrail Traffic Signal System Illumination System Traffic Control Traffic Subtotal $13,040.00 $73, 500.00 $170,000.00 $247,000.00 $100,000.00 Other Items 96-97 Utility Relocates 98-100 Misc. Construction Other Items Subtotal CONSTRUCTION SUBTOTAL CONTINGENCY CONSTRUCTION SUBTOTAL DESIGN ENGINEERING CONSTRUCTION ENGINEERING PROJECT ADMINISTRATION ENGR. AND ADMIN. SUBTOTAL 30% 18% 12% 5% ENVIRONMENTAL ENGINEERING 10% ENVIRONMENTAL MITIGATION 5% ENVIRONMENTAL SUBTOTAL $603,540.00 $100,000.00 $34,600.00 $134,600.00 $6,415,511.00 $ 1 , 924, 660.00 $8,340,171.00 $1,501,240.00 $1,000,830.00 $417.010.00 $2,919,080.00 $834,020.00 $417,010.00 $1,251,030.00 ROADWAY IMPROVEMENTS (a+b+c) ROADWAY RIGHT-OF-WAY ROADWAY SUBTOTAL MARKET CONTIGENCY _ ROADWAY TOTAL (d) 20% $12,510,000 $6,900,000 $19,410,000' $3,880,006 $23,290,000 RAILROAD IMPROVEMENTS RAILROAD RIGHT-OF-WAY RAILROAD SUBTOTAL MARKET CONTIGENCY RAILROAD TOTAL le) 20% $0 $0 $0' $o $o TOTAL PROJECT COST (d+e) (Year 2016) $23,300,000 Page 1 of 1 Printed: 11/28/2016 P III1UKA0000001310600INFO10650DesignDocs10653Estimates104_BNSF Access Cost Est Gateway xis City of Tukwila BNSF Intermodal Access Study Planning Level Cost Estimate Jtemate: Location: Length: Description: Assumptions: 48th Avenue South Interurban Avenue S to BNSF Intermodal Faciiity 2600' DAVID EVANS ANDASSOCIATES INc• Date: Prepared by: Checked by: 11/28/16 MLF Alternative uses 48th Avenue S, over Duwamish River, and ties into the southern end of BNSF yard See alternative exhibit Existing Widths: Proposed Widths: Pavement Vanes 40' to 52' Pavement 44' Preparation 1 Mobilization 2-4 Preparation Items 5-12 Removal Items Preparation Subtotal $505,500.00 $90,600.00 $71,671.00 Grading 13-14 Roadway Grading 15-22 Roadway Foundation 23-28 Utility Excavation Grading Subtotal $667,771 00 $950.00 $110,341.00 $23,760.00 $135,051 00 Storm Drainage 29-40 Conveyance System 41 Culvert/Stream Crossing 42 Detention/Water Quality Facility Storm Drainage Subtotal $201,800.00 $0.00 $750,000.00 $951,800.00 Hot Mix Asphalt Pavement 43-49 Hot Mix Asphalt Pavement $164,065.00 HMA Subtotal $164,065.00 Concrete 50-51 Sidewalks and Driveways 52-53 Curbs and Gutters 54 Concrete Roadway Concrete Subtotal $129,400.00 $65,850.00 $0.00 $195,250.00 Sidewalk 0 Sidewalk 6' both sides Right -of -Way Varies 60' to 80' Right -of -Way 67' Structures 55-59 Retaining Walls 60 Bridge Structure Structure Subtotal $115,250.00 $2,323,200.00 TESC and Landscaping 61-63 TESC 64-68 Plantings 69-70 Irrigation TESC and Landscaping Subtotal $2,438,450.00 $256,400.00 $136,820.00 $44,280.00 $437,500.00 Traffic 71-79 80-83 84-88 89-91 92 97 Markings and Signing Guardrail/Handrail Traffic Signal System Illumination System Traffic Control Traffic Subtotal $7,844.00 $94,000,00 $180,000.00 $279,000,00 $50,000.00 $610,844.00 Other Items 98-99 Utility Relocates 100-102 Misc. Construction Other Items Subtotal CONSTRUCTION SUBTOTAL CONTINGENCY CONSTRUCTION SUBTOTAL DESIGN ENGINEERING CONSTRUCTION ENGINEERING PROJECT ADMINISTRATION ENGR. AND ADMIN. SUBTOTAL 30% 18% 12% 5% ENVIRONMENTAL ENGINEERING 10% ENVIRONMENTAL MITIGATION 5% ENVIRONMENTAL SUBTOTAL $206,000.00 $18,200.00 $224, 200.00 $5,824,931.00 $1,747,480.00 $7,572,411.00 $1,363,040,00 $908,690.00 $378,630.00 $2,650,360.00 $757,250.00 $378,630.00 $1,135,880.00 ROADWAY IMPROVEMENTS (a+b+c) ROADWAY RIGHT-OF-WAY ROADWAY SUBTOTAL MARKET CONTIGENCY ROADWAY TOTAL Id) 20% $11,360,000 $1,900,000 S13,260,000 $2,650,000 $15,910,000 RAILROAD IMPROVEMENTS RAILROAD RIGHT-OF-WAY RAILROAD SUBTOTAL MARKET CONTIGENCY RAILROAD TOTAL (el 20% $3,700,000 $0 $3,700,000 $740,000 $4,440,000 TOTAL PROJECT COST (d+e) (Year 2018) $20,400,000 P:1l1TIJKA0000001310600INF010650DeslgnDocs10653EslImeles105 BNSF Access Cost Est 4Blh xis Page 1 of 1 Printed: 7112612016 Attachment B Geotechnical Report RECEIVED JAN 05 2017 CDEVELo'MLNT • • 1 Geotechn Ica! Engineering Services Report City of Tukwila - BNSF Intermodal Yard Facility Access Tukwila, Washington for David Evans and Associates, Inc. June 2, 2016 • • II • GEOENGINEERS Earth Scirncr + IpclnuIc] y Geotechnical Engineering Services Report City of Tukwila - BNSF Intermodal Yard Facility Access Tukwila, Washington for David Evans and Associates, Inc. June 2, 2016 GEOENGINEERS� 1101 South Fawcett Avenue, Suite 200 Tacoma, Washington 98402 253.383.4940 Geotechnical Engineering Services Report City of Tukwila - BNSF intermodal Yard Facility Access Tukwila, Washington File No. 0259-055-00 June 2, 2016 Prepared for: David Evans and Associates, Inc. 415 118th Avenue SE Bellevue, Washington 98005 Attention: Manual Feliberti, PE Prepared by: GeoEngineers, Inc. 1101 South Fawcett Avenue, Suite 200 Tacoma, Washington 253.383.. s 40 Brett E. Larabee, PE Geotechnical EngI er nnis (D.J.) ompson, PE clate BEL•US:DJI:tt Disclaimer:Any electronic fomr, facsimile or hard copy of the original document (email, text, table, and/or figure), If provided, and any attachments are only a copy of the original document The original document Is stored by GeoEngineers, Inc. and WIII serve as the official document of record. GEOENGINEERSi Table of Contents INTRODUCTION AND PROJECT UNDERSTANDING 1 SCOPE OF SERVICES 1 PROJECT LOCATION AND ROUTE DESCRIPTIONS 2 Airport Way Alternative 2 South 112th Street Alternative 2 South 124th Street Alternative 2 Gateway Drive Alternative 2 48th Avenue South Alternative 2 GEOLOGIC SETTING 3 General 3 Published Geology 3 Alluvium (Qal) 3 Bedrock (Tpt) 4 Glacial Deposits (Qvt), (Qp) 4 Geologic Hazards 5 Regional Seismicity 5 Site Response 5 Liquefaction 6 Slope Instability 6 Erosion 6 DISCUSSION OF ROUTE ALTERNATIVES 7 Airport Way Alternative 7 Route Description and Surface Conditions 7 Route Geology and Anticipated Soil Conditions 7 Anticipated Construction 8 Bridge Foundations for the South Boeing Access Road Overpass 9 South 112th Street Alternative 10 Route Description and Surface Conditions 10 Route Geology and Anticipated Soil Conditions 10 Anticipated Construction 11 South 124th Street Alternative 11 Route Description and Surface Conditions 11 Route Geology and Anticipated Soil Conditions 12 Anticipated Construction 12 Gateway Drive Alternative 13 Route Description and Surface Conditions 13 Route Geology and Anticipated Soil Conditions 14 Anticipated Construction 14 Bridge Foundations 17 GEOENGINEERS� June 2, 20161 Page i File Na. 0259-055-00 48th Avenue South Alternative 17 Route Description and Surface Conditions 17 Route Geology and Anticipated Soil Conditions 18 Anticipated Construction 19 LIMITATIONS 22 REFERENCES 22 LIST OF FIGURES Figure 1. Access Alternatives Figure 2. Northern Access Alternatives Figure 3. Southern Access Alternatives Figures 4 through 8 - Route Alternatives APPENDIX Appendix A. Report Limitations and Guidelines for Use GEOENGINEERLO June 2, 20161 Page ii F le No 0259.055 00 INTRODUCTION AND PROJECT UNDERSTANDING This report provides a summary of our geotechnical engineering study performed for the Tukwila Burlington Northern Santa Fe (BNSF) Intermodal Facility Access project located in Tukwila, Washington. The purpose of this project is to improve access to the BNSF Intermodal Facility and improve traffic flow through the surrounding neighborhoods. Our understanding of the project is based on our discussions with and information provided by David Evans and Associates, Inc. (project Civil Engineers and Planners), which included attending a kickoff meeting on May 19, 2015. The project at this stage consists of evaluating five alternative alignments to improve access to and from the Tukwila BNSF Intermodal Facility to major surface streets and highways. Currently, the BNSF Intermodal Facility is accessed via South 124th Street. Trucks enter the facility at an access point located near the intersection of South 124th Street and 51st Place South. Five alternative access routes have been identified at this time. The approximate locations of the five identified access alternatives are shown on the Vicinity Map and Site Plans, Figures 1 through 8. The five alternatives are as follows: ▪ Airport Way Alternative (see Figure 2 and Figure 4 ) ■ South 112th Street Alternative (see Figure 2 and Figure 5 ) ■ South 124th Street Alternative (see Figure 3 and Figure 6) ■ Gateway Drive Alternative (see Figure 3 and Figure 7) ■ 48th Avenue South Alternative (see Figure 3 and Figure 8) SCOPE OF SERVICES The purpose our services is to conduct a document review and field reconnaissance of the proposed alternatives and to compile that information into a report that will provide the design team with a preliminary, conceptual level summary of known and apparent geologic and geotechnical conditions relevant to project design and construction. Environmental issues will be summarized in a separate report prepared by GeoEngineers. This report has been prepared in accordance with our signed agreement dated April 8, 2015. Our specific geotechnical scope of services includes: 1. Developing a preliminary understanding of geologic conditions at the five proposed alignments by reviewing information you provided, readily available published geologic data and our in-house files. 2. Conducting a site visit and visual reconnaissance of the five potential roadway locations described above. We completed our site visit on June 9, 2015. 3. Discussing our preliminary findings with you. We provided our preliminary findings via emails during the project study period. 4. Identifying geotechnical conditions along the alignment. We have included our preliminary opinions regarding possible design and construction issues related to geology, soil, and groundwater conditions based on our findings, reconnaissance and discussions. GEOENGINEERS June 2, 2016 Page 1 File No. 0259.055.00 5. Preparing this report presenting a summary of our review, reconnaissance and our preliminary conclusions and recommendations. PROJECT LOCATION AND ROUTE DESCRIPTIONS The BNSF Intermodal Yard is located between the Duwamish River and Interstate 5 (1-5). The project vicinity is shown on Figure 1. The northern boundary of the BNSF Intermodal Yard is defined by the South Boeing Access Road overpass at 1-5. The eastern boundary of the BNSF Intermodal Yard is defined by a slope that separates the yard and railroad tracks from 1-5. This slope also forms the eastern edge of the Duwamish River Valley in the project area. The southern boundary of the BNSF Intermodal Facility is defined by the South 129th Street viaduct. The western edge of the BNSF Intermodal Yard is defined by residential and commercial neighborhoods. Airport Way Alternative The Airport Way alternative would connect the northern end of the BNSF Intermodal Yard to Airport Way South via a new roadway constructed along the west side of the existing railroad tracks. The new access road would pass under the existing South Boeing Access Road overpass and connect to Airport Way South approximately where the northbound ramp leaving the South Boeing Access Road overpass connects with Airport Way South. As a part of this alternative, the South Boeing Access Road Bridge/Overpass will be replaced. The preliminary alignment of the Airport Way alternative is shown on Figure 4. South 112th Street Alternative The South 112th Street alternative would connect East Marginal Way South with the BNSF Intermodal Yard via a new roadway constructed between intersection of East Marginal Way South and South 112th Street and the BNSF Intermodal Yard. Currently, South 112th Street dead ends at East Marginal Way. The preliminary alignment of the South 112th Street alternative is shown on Figure 5. South 124th Street Alternative The BNSF Intermodal Yard is currently accessed via South 124th Street. This alternative would consist of improvements to the existing access route. There would be no major changes to the current alignment of South 124th Street. Improvements for this alternative would begin near the intersection of South 124th Street with 42nd Avenue and continue along South 124th Street to the current BNSF Intermodal Yard entrance. Included with this alternative will be reconstruction of the bridge over the Duwamish River on 42nd Avenue. The preliminary alignment of the South 124tt1 Street alternative is shown on Figure 6. Gateway Drive Alternative The Gateway Drive alternative would connect the southern end of the BNSF Intermodal Yard to Interurban Avenue South via a new bridge over the Duwamish River, a new roadway through existing automobile parking areas located on the east side of the river, and then a new connection with Gateway Drive. The preliminary alignment of the Gateway Drive alternative is shown on Figure 7. 48th Avenue South Alternative The 48th Avenue South alternative would connect the southern end of the BNSF Intermodal Yard to Interurban Avenue South via a new road below the South 129th Street viaduct, a new bridge over the GEOENGINEERSg June 2, 2016 Page 2 F No 0259 055 00 Duwamish River, and a connection to the existing 48th Avenue South roadway. The preliminary alignment of the 48th Avenue South alternative is shown on Figure 8. GEOLOGIC SETTING General The site is situated within the Duwamish River valley, which is part of the Puget Lowland, an elongate topographic basin between the Cascade Range and Olympic Mountains. The area has been impacted by episodic glaciation throughout the past 2.4 million years and by tectonic deformation associated with the Cascadia Subduction Zone (CSZ). The landscape has formed largely as a result of repeated cycles of glacial scouring and deposition, tectonic activity, and has also been modified by landslides, stream erosion and deposition, and human activity. Prior to human modifications, the Duwamish River was a natural distributary channel of the Cedar and Green Rivers, as well as the White River. These rivers originate on the flanks of Mount Rainier, a large active stratovolcano of the Cascade Range. After deglaciation of the most recent continental glacier, a glacially scoured fjord (a narrow inlet of the sea formed by glacial scour) was revealed in the present location of the Duwamish River valley. This fjord was infilled with alluvial sand, silt, and gravel sediment derived from erosion and occasional episodic volcanic debris flows (lahars) from Mount Rainier. These lahars caused the delta front to prograde towards its present position at the southeast end of Elliot Bay. Thin, peaty lake deposits also have formed in the alluvial floodplains of the Duwamish valley. Published Geology We reviewed the Geologic Map of Seattle (Troost and others, 2005) and the Geologic Map of the Des Moines Quadrangle (Booth and others, 2004). Predominate geologic units mapped in the area of the proposed route alternatives include: alluvium, bedrock and glacial deposits. Alluvial deposits are mapped in the lowland areas around the Duwamish River. The route alternatives are primarily located within the areas mapped as alluvial deposits. Bedrock is mapped along the southeastern edge of the Duwamish River valley in the project area. Exposed bedrock outcrops are also mapped near the Airport Way and South 112th Street route alignments to the west of the BNSF Intermodal Yard. Glacial deposits area mapped along the southwestern edge of the project area and near the north end of the BNSF Intermodal Yard. The following sections provide descriptions of each unit and their pertinent engineering properties. Alluvium (Qal) Alluvium is a mixture of sand, silt, gravel, and cobbles deposited by rivers and running water. lnterbedding of soil layers (e.g., silt and sand) is common in alluvium. Alluvium is generally very loose to medium dense, or very soft to stiff. Granular alluvial soils are generally suitable for roadway and foundation subgrades, however, special considerations may be necessary depending on the type of alluvium present and the desired performance of the soil. When saturated, alluvium consisting of loose to medium dense sand or soft silts are susceptible to liquefaction. Alluvial deposits are often susceptible to settlement under static conditions due to new construction loads, foundation loads and loading from the placement of fill material. Mitigation of alluvial GEOENGINEERS_O June 2, 2016 Page 3 File Na 0253 055 00 soils is often necessary to reduce the risk of liquefaction, improve foundation bearing capacity, improve roadway subgrade conditions, and to reduce the risk of static settlements under new construction loads. Peat and organic silt deposits are often present in alluvial deposits and in wetland areas. Peat is an organic rich soil -like material that primarily consists of partially decomposed plants and other organic material. Peat is generally normally consolidated and has a persistently high moisture content. Peat and soft organic silt deposits have the highest potential for compression settlements under new loads. Peat and organic silts are not suitable for foundation or roadway subgrade support and need to be either removed or remediated prior to construction. The workability of alluvial soils is influenced by the moisture content and gradation characteristics of the soil especially the fines (percent of material smaller than a U.S. #200 sieve) content. Soils with a high fines content (generally greater than about 5 to 10 percent by weight) are considered moisture sensitive and can be very difficult or impossible to work with when wet or at a moisture content above the "optimum" moisture content. Alluvial soils often have a natural moisture content above the optimum moisture content so special considerations may be necessary when working with alluvial soils. Infiltration characteristics of alluvial soils varies based on the gradation characteristics. Alluvial soils such as gravels with low silt contents can have high infiltration capacity. Alluvial soils such as silts have a low infiltration capacity and are often not suitable for infiltration. Bedrock (Tpt) Bedrock in the project area is mapped as part of the "Tukwila Formation." This formation is described in the literature as "andesitic sandstone, tuff, mudflow breccia, and minor lava flows of sills". Bedrock is generally hard but can be highly fractured in weathered zones. Competent bedrock outcrops can provide high bearing capacity for foundations and roadways. Preparing bearing surfaces and subgrades in bedrock can require additional excavation efforts (compared to excavating through soil) such as drilling and blasting or specialized construction equipment designed for working with bedrock. Bedrock can provided high bearing resistance for deep foundations such as piles or drilled shafts. Specialized construction methods such as predrilling or rock socketing is often required when installing deep foundations into bedrock. Bedrock is considered impermeable from a stormwater infiltration standpoint. Bedrock is not liquefiable. Glacial Deposits (Qvt), (Qp) Glacial deposits mapped in the project vicinity include Vashon till (Qvt) and older glacial deposits (Qp). Vashon till, commonly referred to as till or "hardpan" was deposited during the Vashon Stade of the Fraser glaciation. Vashon till is generally composed of silty sand with gravel and occasional cobbles and boulders, but can include lenses of silt, sand, and gravel. Soils mapped as older glacial deposits (Qp) are likely similar in composition to Vashon till, however, were deposited prior to the Fraser glaciation. Till and older glacial deposits are generally highly compact. Glacial soils are often well suited for foundation bearing support (for both shallow and deep foundations) and roadway subgrades. The risk for liquefaction and static settlement in glacial deposits is usually low compared to alluvial soils. The workability of glacial soils is most commonly influenced by the moisture content and gradation characteristics of the soil GEOENGINEERS_,0 June 2, 2016 Page 4 File No 0259 055 00 especially the fines content. Vashon till is generally considered moisture sensitive due to the high fines content of the soil. Vashon till generally has a low stormwater infiltration capacity. Large boulders and cobbles are often present in glacial soils. Cobbles and boulders can obstruct installation of deep foundations and can impact grading and earthwork activities. Geologic Hazards Geologic hazards in the project area include, general regional seismicity, seismic ground motion amplification, seismically induced liquefaction and lateral spreading, slope instability, and erosion. The sections below provide a brief discussion of these hazards and where they have been identified. Regional Seismicity The Puget Sound region is located at the convergent continental boundary known as the CSZ, which extends from mid -Vancouver Island to Northern California. The CSZ is the zone where the westward advancing North American Plate is overriding the subducting Juan de Fuca Plate. The interaction of these two plates results in three potential seismic source zones: (1) a shallow crustal source zone; (2) the Benioff source zone; and (3) the CSZ interplate source zone. The shallow crustal source zone is used to characterize shallow crustal earthquake activity within the North American Plate at depths ranging from 3 to 19 miles below the ground surface. The Seattle Fault Zone is considered a shallow crustal source zone. The project site is located near the current geologic interpretation of the southernmost strand of the east -west trending Seattle Fault Zone. The most recent major earthquake on the Seattle Fault Zone is estimated to have occurred about 1,100 years ago. The Benioff source zone is used to characterize intraplate, intraslab or deep subcrustal earthquakes. Benioff source zone earthquakes occur within the subducting Juan de Fuca Plate at depths between 20 and 40 miles. In recent years, three large Benioff source zone earthquakes occurred that triggered liquefaction in some loose alluvial deposits similar to those found in the Duwamish River valley and significant damage to some structures. The first earthquake, which was centered in the Olympia area, occurred in 1949 and had a Richter magnitude of 7.1. The second earthquake, which was centered between Seattle and Tacoma, occurred in 1965 and had a Richter magnitude of 6.5. The third earthquake, which was located in the Nisqually valley north of Olympia, occurred in 2001 and had a Richter magnitude of 6.8. The CSZ interplate source zone is used to characterize rupture of the convergent boundary between the subducting Juan de Fuca Plate and the overriding North American Plate. The depth of CSZ earthquakes is greater than 40 miles. No earthquakes on the CSZ have been instrumentally recorded; however, through geologic records and historical records of tsunamis, it is believed that the most recent CSZ event occurred in the 1700s. Site Response Depending on the soil conditions, ground motion amplification during seismic events can occur. Site classification, or site class, is a simplified system of characterizing the ground -motion amplifying effects of soft soils in the upper 100 feet of the soil -rock column. Site class designation and the corresponding site class factors are used in conjunction with seismic deaggregation analyses to calculate the seismic values used for design of structures. GEOENGINEERs June 2, 2016 Page 5 Fite No 0259 055 00 Based on our review of the Site Class Map of King County, Washington (Palmer, 2004) the majority of the alluvial soils in the vicinity of the proposed routes are mapped as "Site Class 0 to E." Bedrock outcrops are mapped as "Site Class B." Liquefaction Liquefaction refers to the condition by which vibration or shaking of the ground, usually from earthquake forces, results in the development of excess pore pressures in saturated soils, and the subsequent loss of strength in the affected soil deposit. In general, soils that are susceptible to liquefaction include very loose to medium dense clean to silty sands and some silts that are below the water table. These soil types and groundwater conditions are likely present in the alluvial soils in the project vicinity. Liquefaction effects on foundations can include a temporary loss of bearing capacity, settlement of the ground surface and downdrag loads on pile and shaft foundations. Liquefaction effects on roadways include pavement cracking and uneven settlement. Ground improvement techniques such as stone columns are commonly used to mitigate liquefaction hazard and effects. Based on our review of the Liquefaction Susceptibility Map of King County, Washington (Palmer and others, 2004), the liquefaction susceptibility of the alluvium, which comprises the majority of soil in the vicinity of the route alternatives, is "moderate to high." Lateral spreading involves lateral displacements of large volumes of liquefied soil. Lateral spreading can occur on near -level ground as blocks of surface soils are displaced relative to adjacent blocks. Lateral spreading also occurs as blocks of surface soils are displaced toward a nearby slope or free -face such as the banks of a river. Riverbanks are located near or within the South 124th Street, Gateway Drive, and 48th Avenue South alternatives. Slope Instability Slopes steeper than about 15 degrees are often considered hazardous especially during seismic events. When planning to construct in areas with significant slopes, regrading of the slopes, constructing retaining walls, or reinforcing the toe of the slopes may be required in order to improve or maintain slope stability. According to the City of Tukwila Sensitive Areas Map slopes steeper than about 15 degrees are mapped near the bedrock outcroppings near the Airport Way and South 112th Street alternatives and along the banks of the Duwamish River near the Gateway Drive and 48th Avenue South alternatives. Generally speaking, rock slopes can be safely inclined at steeper angles than soil slopes. We anticipate that the current rock slope angles will not need to be significantly modified if construction takes place adjacent to these rock slopes. The steep slopes along the river bank are at potential risk of ongoing erosion and undercutting from river flow. These slopes will likely need to be significantly modified or reinforced in order to improve stability if construction takes place near the slopes. Erosion Erosional forces such as rivers or surface water runoff can weaken the face or toe of slopes leading to stability issues. Generally speaking, erosion on the face of slopes can cause smaller surficial sloughing failures that generally have a low impact to surrounding improvements. Erosional forces at the toe of slopes can cause larger global -type slope failures. Global failures have deeper slide planes compared to sloughing failures and as a result have a higher potential to impact structures and other improvements. Generally, slope face erosion can be controlled and managed with a properly implemented erosion and sedimentation GEOENGINEERS� June 2, 2016 Page 6 Re No. 0259.055.00 control plan and routine maintenance. Toe erosion can be comparatively more difficult to address especially if the erosion is caused by river flows. Engineered solutions such as armored slopes are commonly used to prevent or reduce the rate of toe erosion. Other options could include re-routing or re -directing rivers or surface water runoff away from the erosion prone area. DISCUSSION OF ROUTE ALTERNATIVES The following sections discuss the results of our field reconnaissance and document review. We discuss each route individually. Our field investigation and this report focus specifically on geological and geotechnical considerations. Airport Way Alternative Route Description and Surface Conditions The Airport Way alternative would connect the northern end of the BNSF Intermodal Yard to Airport Way South. There is currently a gravel and asphalt paved roadway in the alignment area. Railroad tracks form the east boundary of the alignment. The western boundary of the alignment passes near areas mapped as bedrock and as wetland areas. During our site visit we observed standing water in the wetlands. Construction of the Airport Way alternative would primarily consist of constructing a new roadway. Based on the provided alignment and our site reconnaissance, we anticipate that retaining walls may be required where the alignment is adjacent to the mapped wetland area. The South Boeing Access Road Bridge/Overpass will be replaced as a part of this alternative. The proposed alignment is shown on Figure 4. Route Geology and Anticipated Soil Conditions Mapped geology near the Airport Way alternative is shown on Figure 2. We anticipate that this alternative would primarily be constructed on top of alluvium. Bedrock could be encountered near the South Boeing Access Road overpass depending on the specific alignment. We anticipate that peat could be encountered near the wetlands area located at the north end of the route. We reviewed boring logs completed for the South Boeing Access Road overpass where located over 1-5 (Soil Sampling Service, 1964). Soil types described in the borings near the ground surface included lenses of peaty silt and loose or very soft saturated sand and silt. Bedrock was encountered in the borings located near the mapped rock outcropping. The bedrock was described as "solid but weathered" in one of the boring logs. The soil conditions in the boring logs we reviewed near the Airport Way route alignment are generally consistent with our interpretation of the mapped geology. Based on the site location we expect groundwater to be relatively shallow in the area. We anticipate that groundwater elevation in the area of the Airport Way alternative will be within a few feet of the elevation of water in the Duwamish River. Groundwater elevation near the wetland area will likely be locally influenced by the standing water elevation in the wetlands. Groundwater elevation is expected to fluctuate due to seasons, precipitation, and water levels in the river and wetland. GEOENGINEERS� June 2, 2016 Page 7 File No 0259 055.00 Seismic site class along this route alignment will likely be D or E in the alluvium and B on and surrounding the bedrock outcroppings. Liquefaction susceptibility along the route alignment is likely moderate to high within the alluvium. Anticipated Construction Roadway Improvements The Airport Way alternative will require construction of a new paved roadway over an existing gravel and asphalt access road. The new roadway would likely be wider than the existing access road. The alignment profile shows that the new roadway will be constructed at or near current grade in the area. Constructing the new roadway would require clearing and stripping vegetation and other obstructions, realigning or installing utilities, establishing the roadway subgrade and subbase, placing and compacting roadway base course materials, and placing the new roadway pavement. Widening the existing gravel and asphalt roadway could require excavating through bedrock. Retaining walls may be required to support cut slopes or to construct the roadway near the wetlands area (see "Retaining Walls" section below). Geologic mapping only addresses near surface geology; shallow bedrock could also be encountered in the areas beyond the areas mapped as bedrock outcroppings. Excavation through rock will be difficult compared to excavation through alluvial soil and could require drilling and blasting. Excavations for underground utilities could encounter shallow bedrock and could also require drilling and blasting. The roadway subgrade will likely be established on alluvial soils and in areas adjacent to wetlands. We anticipate that remediation of some roadway subgrade soils could be required in order to establish subgrade in areas where soft or otherwise unsuitable soils are encountered and/or to reduce the potential for long-term roadway settlement. Typical remediation alternatives for pavement subgrades could include overexcavation (removing and replacing unsuitable soils) or chemical stabilization (e.g., cement mixing, asphalt treated base). If peat is encountered near the subgrade it would need to be completely removed from below the roadway or foundation footprint. If peat is present at depths where removal is impractical, remediation by treatment or preloading/surcharging would be required. Long term continual settlement of the roadway (creep) should be expected if peat is left in place below the roadway. We anticipate that a roadway section typically used for high truck traffic on alluvial soils will be suitable for use at this alignment. These roadway sections typically consist of 6 inches of asphalt, 8 inches of crushed rock, and 12 to 24 inches of gravel base. Sometimes cement treated subgrade (chemical stabilization) is used instead of the gravel base. Ultimately, pavement design sections will depend on the amount and type of traffic and subgrade conditions. We anticipate that most roadway construction for this alternative can be accomplished using conventional construction equipment and techniques. Specialized equipment will be necessary if excavation though bedrock is required. Retaining Walls and Abutments Based on the preliminary location of the roadway alignment, retaining walls are generally not expected to be predominant in the design of this alternative. However, it appears that walls supporting newly placed fill GEOENGINEERS� lune 2, 2016 Page 8 File No 0259 055 00 to support the road could be required near the existing slope that separate the low-lying wetlands area from the existing rail yard and gravel roadway and possibly as abutments or as approaches for the South Boeing Access Road. Conventional cast -in -place concrete walls would likely not be feasible in the wetland areas due to the likelihood of soft soil conditions, unsuitable bearing support, the potential for large differential settlements, and high water levels. Mechanically stabilized earth (MSE) walls may be feasible in the wetlands area since they can withstand larger differential settlements but would require special foundation considerations such as overexcavation and replacement. Specialized retaining walls such as soldier pile walls or a pile supported concrete wall may also be feasible wall alternatives near the wetlands area. If highly compressible soils and/or alluvial soils are present below retaining structures or approach embankment areas, they may need to be remediated. Remediation could involve removal and replacement, preloading and surcharging, or potentially ground improvement. Ground improvement will likely be required below embankments that are taller than about 6 to 8 feet. Stone columns are a commonly used ground improvement technique in alluvial soils. Generally, stone columns in alluvial soils extend to depths between 30 and 50 feet below ground surface. Stone columns are typically installed below and 5 to 10 feet outside the entire embankment footprint. In our experience design displacement ratios on the order of 7 to 10 percent are common for stone columns in alluvial soils. Bridge approaches could also be constructed as elevated viaducts. Typically, this alternative is more expensive than constructing an earth embankment approach because it requires the construction of deep foundations and an elevated roadway. If the approaches are constructed as elevated viaducts, foundation types described in the section below can be considered. Bridge Foundations for the South Boeing Access Road Overpass With the presence of alluvium, wetland areas, and bedrock, abutments and bents could be supported on a combination of shallow footings, intermediate length/depth foundations, and/or deep foundations. In addition, we anticipate that the alluvial soils present below the bridge foundations will be susceptible to liquefaction. Location and depth to bedrock below abutments and piers will likely dictate whether deeper or shallower foundations are more appropriate. We expect that there is a possibility that high resistance values could be developed within the bedrock; however, specialty drilling, ripping, and/or blasting may also be required. Shallow foundations are more susceptible to liquefaction -induced settlement than deep foundations and, therefore, will likely require significant ground improvement to be a feasible option where alluvium and/or soft soil is present. Based on our experience, deep foundations are generally the preferred and most economical alternative for bridges constructed on alluvial soils. Deep foundations typically provide high load capacities and better seismic performance in loose alluvial soil sites when compared to shallow foundations. Both driven piles and drilled shafts are expected to be feasible deep foundation options. Drilled shafts are more common for bridge foundation support in alluvial soils. In our experience a typical 4-foot-diameter drilled shaft can achieve a strength resistance value between 500 to 600 kips at a depth of 80 feet for alluvial soil conditions. Drilled shafts would likely need to be installed using casings or with drilling slurry (mud) to support the hole sidewalls in loose sand saturated alluvial soils. Steel piles could be installed using either vibratory or impact hammers; concrete piles would require installation with an impact hammer. GEOENGINEERS� June 2, 2016 Page 9 Fie No. 0259 055 00 If bridge structure foundations are supported on deep foundations, the piles or shafts would likely need to be designed to resist liquefaction -induced downdrag loads and lateral spreading loads. If shallow foundations are used, loose (or soft) alluvial soils present below the foundation would need to be improved to increase the bearing capacity of the soils, mitigate for liquefaction and to remediate static settlement issues. Remediation techniques such as earthquake drains, vibratory replacement and compaction (stone columns), or jet grouting are possible alternatives. South 112th Street Alternative Route Description and Surface Conditions The South 112th Street alternative connects the intersection of East Marginal Way South and South 112th Street to the BNSF Intermodal Yard. Existing features in the proposed improvement area include a partially developed gravel roadway, an above -ground water pipe, and power transmission line towers. With the exception of the existing gravel roadway, most of the ground surface in the alignment area is covered with grass and small bushes. North of the roadway alignment near where the alignment turns to the northeast there is an existing depression in the topography. We did not observe standing water in this low-lying area; however, we observed grasses and plants that typically grow in wetland type areas. Properties to the north and south of the alignment area include residential and commercial properties, and an active police gun range. Construction of the South 112th Street alternative would primarily consist of constructing a new roadway. Based on the provided alignment and our site reconnaissance we do not anticipate that any walls, bridges, or other major structures would be necessary for this alternative if constructed as currently envisioned. The proposed route alignment is shown on Figure 5. Route Geology and Anticipated Soil Conditions Mapped geology near the South 112th Street alternative is shown on Figure 2. We anticipate that this route would primarily be constructed on top of alluvium. Bedrock could be encountered near the east end of the alignment where the roadway passes near a mapped bedrock outcrop to the south. Peat could be encountered near the low lying area to the north of the roadway alignment. Alluvial soils described in historical boring logs located north of the South 112th Street route alignment area (Soil Sampling Service, 1964) are consistent with our interpretation of the mapped geology and our description of alluvium in this report. We reviewed explorations that were located on top of the bedrock outcrop north of the South 112th Street alignment (Bassi, 1972). The bedrock was described in those explorations as highly fractured. An exploration advanced near the center of the outcrop encountered about 10 feet of overburden before encountering weathered bedrock. We anticipate that overburden depths above the bedrock will vary. Based on the site location we expect groundwater to be relatively shallow in the area. We anticipate that groundwater elevation in the area of the South 112th Street alternative will be within a few feet of the elevation of water in the Duwamish River. Groundwater elevation is expected to fluctuate due to seasons, precipitation, and water levels in the river. Seismic site class along this route alignment will likely be D or E in the alluvium and B near bedrock outcroppings. Liquefaction susceptibility along the route alignment is likely moderate to high within the alluvium. GEOENGINEERS.g June 2, 2016 Page 10 :c Va 0259 055 00 Anticipated Construction Roadway Improvements Constructing the new South 112th Street roadway could require clearing and stripping vegetation and other obstructions from the alignment area, realigning or installing utilities, grading to establish design elevations, preparing the roadway subgrade, and constructing the new roadway section. The new roadway will likely be wider than the existing gravel roadway that is currently located in part of the alignment area. Stripping of existing surface vegetation will be necessary to prepare the area for construction. The roadway alignment does not appear to intersect the mapped bedrock outcrop near the east end of the alignment. However, shallow bedrock could be encountered during clearing and stripping activities, during utility trench excavation, or while preparing the roadway subgrade in the areas near the mapped bedrock outcroppings. Excavation through rock will be difficult compared to excavation though alluvial soil and could require drilling and blasting. If the bedrock is consistently "highly fractured" as described in the reviewed explorations, ripping claws on large excavators or bulldozers might also be effective for excavation. We anticipate that the new roadway subgrade will be established primarily on alluvial soils. Remediation of some alluvial subgrade soils could be required to reduce the potential for long-term roadway settlement and isolated areas of roadway degradation. Remediation alternatives could include overexcavation (removing and replacing unsuitable soils), incorporating geo-synthetics into the subgrade soils or chemical stabilization (e.g., cement mixing, asphalt treated base). If peat is encountered near the subgrade it would need to be completely removed from below the roadway or fill footprint. If peat is present at depths where removal is impractical, remediation by treatment or preloading/surcharging would be required. Long term continual settlement of the roadway (creep) should be expected if peat is left in place below the roadway. We anticipate that a roadway section typically used for high truck traffic on alluvial soils will be suitable for use at this alignment. These roadway sections typically consist of 6 inches of asphalt, 8 inches of crushed rock, and 12 to 24 inches of gravel base. Sometimes cement treated subgrade (chemical stabilization) is used instead of the gravel base. We anticipate that roadway construction for this alternative can be accomplished using primarily conventional construction equipment and techniques. Specialized equipment as described may be necessary if excavation though bedrock is required. South 124th Street Alternative Route Description and Surface Conditions South 124th Street is currently used to access the BNSF Intermodal Yard. South 124th Street passes through a residential neighborhood. The existing roadway is paved with asphalt concrete. Concrete curb and sidewalks are located along the south shoulder of the roadway between 42nd Avenue South and 46th Avenue South. There is no sidewalk on the north side of the roadway, however, the traveling lane is separated from the shoulder by an approximately 3-inch tall concrete curb. The topography along the alignment is generally flat, however, the roadway appears to be built on a fill prism that elevates the roadway about a foot higher than the adjacent side streets and surrounding elevations. GEOENGINEERS_g June 2, 2016 Page 11 File No 0259 055 00 Based on our visual reconnaissance the existing asphalt pavement appears to be in fair condition. We observed isolated areas of cracking. We also observed some areas where the existing pavement was removed and replaced likely for underground utility related construction. Construction of the South 124w Street alternative would consist of improving or rebuilding the existing South 124th Street roadway. This option will also include reconstruction of the bridge on 42nd Street over the Duwamish River. This study relates to South 124th Street and does not address conditions or considerations for the 42nd Street bridge reconstruction. The proposed route alignment is shown on Figure 6. Route Geology and Anticipated Soil Conditions Mapped geology near the South 124th Street alternative is shown on Figure 3. We anticipate that this route would primarily be constructed on top of alluvium or on the existing roadway fill prism that was placed when the existing roadway was constructed. Alluvial soils described in a boring located near the 42nd Avenue South bridge (near the west end of the proposed alignment) (Converse Consultant NW, 1993) generally consisted of loose to medium dense sand with a variable silt content, which is consistent with the mapped geology in the area and our description of alluvium in this report. Glacial till was encountered at depth around 45 feet below ground surface. Based on the site location we expect groundwater to be relatively shallow in the area. We anticipate that groundwater elevation in the area of the South 124th Street alternative will be within a few feet of the elevation of water in the Duwamish River. Groundwater elevation is expected to fluctuate due to seasons, precipitation, and water levels in the river. Site class in the alluvium along this route alignment will likely be D or E. Liquefaction susceptibility of the alluvium along the route alignment is likely moderate to high. Anticipated Construction Roadway Improvements We anticipate that construction of the new South 124th Street roadway could involve demolition of the existing roadway section, installing or realigning utilities, grading to establish design grades, preparing the roadway subgrade, and constructing the new roadway section. We anticipate that demolition of the existing roadway section could be completed using conventional methods. We do not anticipate that a significant amount of stripping or clearing will be required if the new roadway alignment follows the existing road alignment. Grading and earthwork can likely be completed using conventional methods. Depending on the design roadway section and subgrade elevation, cutting through or placing fill on the existing roadway could be required. If cut depths exceed the thickness of the existing fill prism, we anticipate that the natural alluvial soils will be encountered. If fill is placed on top of the existing fill prism, the in -place soils would need to be evaluated for subgrade suitability and the potential for settlement. Any unsuitable areas would likely need to be remediated, which would likely involve removal and replacement of soils or possibly specialized treatment. Depending on the amount of grade the roadway is raised, it may be necessary to pre -load the area to induce settlement and construct shallow retaining walls depending on elevation of the surrounding properties. Settlement of existing utilities may also need GEOENGINEERS. June 2, 2016 Page 12 File No. 0759.055.00 to be considered depending on the depth, presence and thickness of compressible soil deposits and the thickness of fill required for grade development. Based on the observed existing fill prism and the condition of the road surface we anticipate that the existing fill at current grade will provide suitable support for an asphalt and crushed rock pavement section without the need for additional gravel subbase. If the new road grade is established at or near the current road grade we also expect that an asphalt overlay of the existing pavement could be effective for extending the life of the current pavement. The required asphalt overlay section would need to be based on the condition and thickness of the existing pavement and the anticipated increase in the traffic loading. The thickness of the existing roadway section is unknown, but based on observations of the surface we anticipate that an asphalt overlay would consist of about 2 to 3 inches with some excavation and rebuilding of isolated areas with more damage. If the roadway is cut down so that the subgrade is established on alluvial soils, we anticipate that remediation of some alluvial subgrade soils could be required to reduce the potential for long-term roadway settlement and isolated areas of roadway degradation. Remediation alternatives could include overexcavation (removing and replacing unsuitable soils), incorporating geo-synthetics into the subgrade soils or chemical stabilization (e.g., cement mixing, asphalt treated base). If peat is encountered near the subgrade it would need to be completely removed from below the roadway or foundation footprint. If peat is present at depths where removal is impractical remediation by treatment or preloading/surcharging would be required. Long term continual settlement of the roadway (creep) should be expected if peat is left in place below the roadway. For new design and removal of the existing fill, we anticipate that a roadway section typically used for high truck traffic on alluvial soils will be suitable for use at this alignment. These roadway sections typically consist of 6 inches of asphalt, 8 inches of crushed rock, and 12 to 24 inches of gravel base. Sometimes cement treated subgrade (chemical stabilization) is used instead of the gravel base. We anticipate that roadway construction for this alternative can be accomplished using primarily conventional construction equipment and techniques. Gateway Drive Alternative Route Description and Surface Conditions The Gateway Drive alignment begins at the northwestern most intersection of Gateway Drive and Interurban Avenue South. The alignment follows the existing Gateway Drive alignment until Gateway Drive turns to the east. At this point the proposed alignment turns to the north crossing though existing parking areas until reaching the south bank of the Duwamish River. A new bridge oriented approximately northeast would be constructed over the river. On the north side of the river the alignment would pass through a residential area before connecting with the existing entrance of the BNSF Intermodal Yard near the intersection of South 124th Street and 519t Street Place South. The proposed alignment is shown on Figure 7. Gateway Drive is a four -lane roadway paved with asphalt concrete. Concrete curbs, gutters, and sidewalks are located at either edge of the road. There are multiple entrances to Gateway Drive from adjacent parking areas and business. GEOENGINEERLO June 2, 2016 Page 13 He No 0259 055 00 The proposed alignment crosses through an existing parking area located between Gateway Drive and the Duwamish River. This area is surfaced with asphalt pavement and landscaped medians. Trees in the landscaping area are about 6 to 12 inches in diameter. The elevation of the parking area is slightly higher than Gateway Drive. To the north of the parking area is a paved pedestrian pathway (Green River Trail). There is a slope leading down from the pedestrian path to the south river bank. The south river bank in the proposed alignment area appears to have been modified and graded to a slope of around 2H to 1V (horizontal to vertical). The slope is covered with landscaping bark, natural vegetation, and planted landscaping. Trees as large as 24 inches in diameter are located on the south river bank in the area of the proposed alignment. The north river bank around the proposed alignment is heavily vegetated. The slope leading down to the river appears to be over -steepened and possibly undercut, however, we were not able to fully see the face of the north river bank during our reconnaissance due to the dense vegetation. Single family residences are located at the top of the slope in the alignment area. We understand that the proposed bridge crossing the Duwamish River would be a single -span bridge. The south abutment for the bridge would be located near the area of the existing pedestrian pathway. The north abutment will be located inland of the crest of the north river bank slope. On the north side of the river the proposed alignment crosses through a residential neighborhood consisting of single family home sites. The alignment will also cross a two-lane roadway surfaced with asphalt; 50th Place South. Route Geology and Anticipated Soil Conditions Mapped geology around the Gateway Drive alternative is shown on Figure 3. We anticipate that this route would primarily be constructed on top of alluvium or on existing fill overlying alluvium. We reviewed a cone penetrometer test (CPT) exploration log located near the intersection of Gateway Drive and Interurban Avenue (Converse, 1993). Soils described in the log generally consisted of medium dense sand and silty sand and stiff clayey silt, which is consistent with the mapped geology along the alignment and the general description of alluvium in this report. Based on the site location we expect groundwater to be relatively shallow in the area. We anticipate that groundwater elevation in the area of the Gateway Drive alternative will be within a few feet of the elevation of water in the Duwamish River. Groundwater elevation is expected to fluctuate due to seasons, precipitation, and water levels in the river. Site class in the alluvial soils along this route alignment will likely be D or E. Liquefaction susceptibility of the alluvial soils along the route alignment is likely moderate to high. Anticipated Construction Roadway Construction We anticipate roadway improvements will be included as part of this alternative. The existing pavement along Gateway Drive appeared to be in fair condition during our site reconnaissance, however, improvements may be necessary to reinforce the roadway in preparation for new traffic loads. We anticipate that constructing a new asphalt overlay on the existing road section would be effective and cost less than GEOENGINEERSg June 2, 2016 Page 14 File Na.0259.055 00 demolishing the roadway section, establishing subgrade, and then constructing a more robust roadway section. We anticipate that roadway construction for this alternative can be accomplished using primarily conventional construction equipment and techniques. Grade considerations along the alignment leading to bridge approaches will likely need to be considered in the design depending on height requirements of the bridge. The thickness of the existing roadway section is unknown. For a new overlay, the required asphalt thickness would need to be based on the condition and thickness of the existing pavement and the anticipated increase in the traffic loading. If the roadway was originally designed to accommodate regular truck traffic, an asphalt overlay of about 2 to 3 inches may be appropriate. If the roadway was originally designed to accommodate smaller vehicle traffic, an asphalt overlay of about 4 inches may be more appropriate. Constructing the new roadway between Gateway Drive and the proposed bridge location, through the existing parking area, would likely involve clearing and stripping of planted areas, demolishing existing pavement and hardscaping, grading or placing fill to design elevations, establishing roadway subgrades, and constructing the new roadway sections. We expect that a new roadway would need to be constructed north of the Duwamish River between the bridge location and the entrance to the BNSF Intermodal Yard. Constructing the roadway through the residential neighborhood would likely involve demolition, clearing and stripping, grading or placing fill to design elevations, establishing roadway subgrade and constructing the new roadway section. We anticipate that portions of the subgrade for the new roadway sections will be established on natural alluvial soils. Remediation of some areas of alluvial soils could be required to develop a firm subgrade, to reduce the potential for long-term roadway settlement and in isolated areas where roadway degradation has occurred. Remediation alternatives could include overexcavation (removing and replacing unsuitable soils), incorporating geo-synthetics into the subgrade soils, or chemical stabilization (e.g., cement mixing, asphalt treated base). If peat is encountered near the subgrade it would need to be completely removed from below the roadway or foundation footprint. If peat is present at depths where removal is impractical, remediation by treatment or preloading/surcharging would be required. Long term continual settlement of the roadway (creep) should be expected if peat is left in place below the roadway. We anticipate that a roadway section typically used for high truck traffic on alluvial soils will be suitable for use at this alignment. These roadway sections typically consist of 6 inches of asphalt, 8 inches of crushed rock, and 12 to 24 inches of gravel base. Sometimes cement treated subgrade (chemical stabilization) is used instead of the gravel base. Bridge Construction Geotechnical considerations for constructing the new bridge includes: constructing bridge approaches, constructing abutment foundations, and addressing river bank stability issues. Approach Embankment and Retaining Walls: Bridge approaches could be constructed as earth embankments or as elevated viaducts. Earth embankments would need to be founded on suitable subgrade soils. In order to reduce the width of the approach embankments, retaining walls, engineered slopes, or MSE walls may be required to stabilize the edges of the embankment prism. Large area fills such GEOENGINEERLO June 2, 2016 Page 15 File No. 0259.055.00 as approach embankments can cause settlement of underlying soft/compressible soil. If highly compressible soils are present below approach embankment areas, they may need to be remediated. Remediation could involve removal and replacement, preloading and surcharging, or potentially ground improvement. If earth embankment design will include earthquake considerations, ground improvement will likely be required below embankments that are taller then about 6 to 8 feet. Stone columns are a commonly used ground improvement technique in alluvial soils. Generally, stone columns in alluvial soils extend to depths between 30 and 50 feet below ground surface. Stone columns are typically installed below and 5 to 10 feet outside the entire embankment footprint. In our experience design displacement ratios on the order of 7 to 10 percent are common for stone columns in alluvial soils. Retaining walls could be incorporated into the design of the approach embankments, bridge abutments, and slope stabilization configuration. Retaining walls would help limit the footprint of the approach embankment and abutments. Conventional cast -in -place walls or MSE walls could be used when constructing the bridge approach embankments or abutments. More specialized wall types such as soldier pile walls are also feasible. Bridge approaches could also be constructed as elevated viaducts. Typically, this alternative is more expensive than constructing an earth embankment approach because it requires the construction of deep foundations and an elevated roadway. If the approaches are constructed as elevated viaducts, foundation types similar to those described in the "Bridge Foundations" section below can be considered. River Bank Stability: Stability and erosion control of the river bank slopes near the bridge will need to be considered during design. Constructing an earth embankment near the top of the existing slopes could cause slope stability issues under static and seismic conditions. Loads from other bridge elements placed on top of the slopes could have similar impacts to slope stability. Based on the current condition of the river bank slopes near the north and south bridge abutment locations, we anticipate that improvements to both river bank slopes will be necessary to construct the bridge as envisioned. Flatting the slopes, installing cutoff sheet piles, constructing a bench in the slope, constructing a retaining wall, installing riprap or other engineered materials to the face of the slope, or other remediation techniques may be necessary to improve the stability and reduce erosion potential on the slope. Typically, re -graded slopes armored with large diameter rocks (riprap) are economical and effective at stabilizing and preventing slope erosion. The soils near the river bank slopes are likely liquefiable and there is a risk of lateral spreading of the slopes towards the river during a seismic event. Lateral spreading could impact the bridge embankments and could place additional loads on the bridge foundations. The potential for lateral spreading will need to be evaluated at both the north and south slopes and, if necessary, lateral spreading hazard should be mitigated. Typically, lateral spreading mitigation and liquefaction settlement mitigation can be addressed together with either ground improvement, deep foundations designed to accommodate lateral spreading and down drag loads, or a combination of both. GEOENGINEERSQ Bridge Foundations The bridge abutment foundations could be constructed as shallow footings or as deep foundations. We anticipate that soils below the bridge abutments will be susceptible to liquefaction. Shallow foundations are more susceptible to liquefaction -induced settlement than deep foundation and, therefore, will likely require significant ground improvement to be a feasible option. Based on our experience, deep foundations are generally the preferred and most economical alternative for bridges constructed on alluvial soils similar to those in the vicinity of the Gateway Drive Bridge. Deep foundations typically provide high load capacities and better seismic performance in loose alluvial soil sites when compared to shallow foundations. Both driven piles and drilled shafts are expected to be feasible deep foundation alternatives. Drilled shafts are more common for bridge foundation support in alluvial soils. In our experience a typical 4-foot-diameter drilled shaft can achieve a strength resistance value between 500 to 600 kips at a depth of 80 feet. Drilled shafts would likely need to be installed using casings or with drilling slurry (mud) to support the hole sidewalls in loose sand saturated alluvial soils. Steel or concrete driven piles are both likely feasible for constructing the Gateway Drive Bridge. Steel piles could be installed using either vibratory or impact hammers; concrete piles would require installation with an impact hammer. If bridge structure foundations are supported on deep foundations, the piles or shafts would likely need to be designed to resist liquefaction -induced downdrag loads and lateral spreading loads. If shallow foundations are used, the existing loose (or soft) alluvial soils would need to be improved to increase the bearing capacity of the soils, mitigate for liquefaction and lateral spreading and to remediate static settlement issues. Remediation techniques such as earthquake drains, vibratory replacement and compaction (stone columns), or jet grouting are possible alternatives. Stone columns is a commonly used ground improvement technique in alluvial soils. Generally, stone columns below foundations in alluvial soils extend to depths between 30 and 50 feet below ground surface. Stone columns must be installed below the entire foundation and the improvement area generally extends about 5 to 10 feet outside of the foundation footprint. In our experience design displacement ratios on the order of 7 to 10 percent are common for stone columns in alluvial soils. Constructability of shallow foundations will also be affected by shallow groundwater levels. The area of the footings may need to be dewatered in order to construct the foundations below the groundwater table. 48th Avenue South Alternative Route Description and Surface Conditions Constructing the 48th Avenue South alternative would require constructing new roadways, improving or rebuilding existing roadways, and constructing a new bridge over the Duwamish River. The proposed alignment is shown in Figure 8. The proposed alignment follows the existing 48th Avenue South alignment between Interurban Avenue South and the Duwamish River. 48th Avenue South is a two-lane roadway that dead ends near the Duwamish River. 48th Avenue South is paved with asphalt concrete; concrete sidewalks and curb and gutters are located on either side of the roadway. Near the north end of 48th Avenue South the concrete sidewalks end and the roadway shoulders are unimproved. There appears to be a drainage ditch on the east side of the roadway near the dead end. GEOENGINEERS� June 2, 2016 Page 17 Flle No 0259 055 00 The 48th Avenue South alternative will cross the Duwamish River on a single -span bridge. The proposed alignment shows that the bridge will be oriented approximately north -south. The proposed alignment shows that the south bridge abutment will be located on the river side of the pedestrian path. The south river bank slope is currently covered with natural vegetation including tress as large as 24 inches in diameter. The south river bank slope does appears to be at a gradient between 1H to 1V and 2H to 1V. The proposed alignment shows that the north bridge abutment will be located on the river side of Railroad Avenue. Railroad Avenue is currently a two-way road paved with asphalt concrete. Railroad Avenue currently runs along the north river bank adjacent to the crest of the slope. Concrete jersey barriers separate Railroad Avenue from the slope. The north river bank appears to be over -steepened and may be undercut below the waterline. The north river bank slope is heavily vegetated so we were not able to visually evaluate the condition of the slope. We understand that the grade of Railroad Avenue will be raised in the area of the bridge to accommodate the construction of the bridge approach. A new section of roadway will be constructed between the north bridge abutment and the BNSF Intermodal Yard. The proposed alignment shows the new roadway will pass under the South 129th Street overpass and entering the south end of the BNSF Intermodal Yard. The area between Railroad Avenue and the BNSF Intermodal Yard is currently unimproved and is un-vegetated. Route Geology and Anticipated Soil Conditions Mapped geology around the 480 Avenue South alternative is shown on Figure 3. We anticipate that this route would primarily be constructed on top of alluvium. Bedrock is mapped near the area of the north bridge abutment and we observed exposed bedrock on the hillside to the northeast of the alignment location. It is possible that shallow bedrock is present in the area of the 48th Avenue South alternative. Shallow bedrock is most likely to be present on the north side of the Duwamish River areas close to the hillside. We reviewed historic exploration logs from projects located on the north and south sides of the Duwamish River in the area on the 48th Avenue South alignment. On the south side of the river we reviewed a boring log near the intersection of 48th Avenue South and Interurban Avenue (Converse, 1993). Soils described in the log generally consisted of medium dense sand and silty sand and stiff clayey silt, which is consistent with the mapped geology along the alignment and the general description of alluvium in this report. On the north side of the river we reviewed exploration logs located to the north of the BNSF Intermodal Yard railroad tracks adjacent to the slope that forms the edge of the Duwamish River valley. Soils described in the reviewed logs consisted of alluvial soils overlying bedrock. The bedrock was described as partially fractured and moderately to highly weathered. The depth to bedrock varied in the exploration logs, however, in the one exploration log located near the existing tracks (similar surface elevation to the area of the proposed bridge), bedrock was encountered at about 20 feet below ground surface. We anticipate that the depth to bedrock will vary in the area of the project site and in general, will be deeper as you move further away from mapped bedrock locations and the valley walls. Based on the site location we expect groundwater to be relatively shallow in the area. We anticipate that groundwater elevation in the area of the 48th Avenue South alternative will be within a few feet of the elevation of water in the Duwamish River. Groundwater elevation is expected to fluctuate due to seasons, precipitation, and water levels in the river. Site class in the alluvial soils along this route alignment will likely GEOENGINEERS� June 2, 2016 Page 18 File No. 0259.055.00 be D or E. Liquefaction susceptibility of the alluvial soils along the route alignment is likely moderate to high. Anticipated Construction Roadway Construction Roadway construction for the 48th Avenue South alternative would require constructing a new roadway between the north end of the new bridge and the BNSF Intermodal Yard and could require improving the existing 48th Avenue South roadway. We anticipate that constructing a new asphalt overlay on the existing road section would be effective and cost less than demolishing the roadway section, establishing subgrade, and then constructing a more robust roadway section. We anticipate that roadway construction for this alternative can be accomplished using primarily conventional construction equipment and techniques. The existing pavement along 48th Avenue South appeared to be in fair condition during our site reconnaissance, however, improvements may be necessary to reinforce the roadway in preparation of the new traffic loads. We anticipate that roadway improvements could include placing a new asphalt overlay on the existing road section or demolishing the roadway section, establishing subgrade, and then constructing a new roadway section. The required asphalt overlay for the existing portion of 48th Avenue South would need to be based on the condition and thickness of the existing pavement and the anticipated increase in the traffic loading. The thickness of the existing roadway section is unknown. If the roadway was originally designed to accommodate regular truck traffic, an asphalt overlay of about 2 to 3 inches may be appropriate. If the roadway was originally designed to accommodate smaller vehicle traffic, an asphalt overlay of about 4 inches may be more appropriate. As part of this alternative, a new roadway would be constructed to the north of the D,uwamish River between the bridge and the BNSF Intermodal Yard. Constructing the roadway through this area would likely involve clearing and stripping, grading or placing fill to design elevations, establishing roadway subgrade, constructing the new roadway section, and constructing a new intersection at Railroad Avenue. We anticipate that subgrade for most of the roadway sections will be established on natural alluvial soils. Remediation of some areas of alluvial soils could be required to reduce the potential for long-term roadway settlement and isolated areas of roadway degradation. Remediation alternatives could include overexcavation (removing and replacing unsuitable soils), incorporating geo-synthetics into the subgrade soils, surcharging (loading compressible soils with a temporary surcharge to induce settlement prior to roadway construction) or chemical stabilization (cement mixing, asphalt treated base). If peat is encountered near the subgrade elevation it would need to be completely removed from below the roadway to reduce the potential for settlement. If peat is present at depths where removal is impractical, remediation by treatment or preloading/surcharging would be required. Long term continual settlement of the roadway (creep) should be expected if peat is left in place below the roadway. We anticipate that a roadway section typically used for high truck traffic on alluvial soils will be suitable for use at this alignment. These roadway sections typically consist of 6 inches of asphalt, 8.inches of crushed rock, and 12 to 24 inches of gravel base. Sometimes cement treated subgrade (chemical stabilization) is used instead of the gravel base. GEOENGINEERS� June 2, 2016 Page 19 Ale No 0259.055.00 Bridge Construction Geotechnical considerations for constructing the new bridge includes; addressing river bank stability, constructing bridge approaches and, constructing abutment foundations River Bank Stability: Stability and erosion control of the river bank slopes near the bridge will need to be considered during design. Constructing an earth embankment near the top of the existing slopes could cause slope instability under static and seismic conditions. Loads from other bridge elements placed on top of the slopes could have similar impacts to the slope. Based on the current condition of the riverbank and the slopes near the north and south bridge abutments, we anticipate that improvements to both river bank slopes will be necessary to construct the bridge as envisioned. Flatting the slopes, installing cutoff sheet piles, constructing a bench in the slope, constructing a retaining wall, installing large rock (riprap) or other engineered materials to the face of the slope, may be necessary to improve the stability and reduce the potential for erosion. Typically, re -graded slopes armored with large diameter rocks/riprap are economical and effective at stabilizing and preventing slop erosion. The soils near the river bank slopes are likely liquefiable and there is a risk of lateral spreading of the slopes towards the river during a seismic event. Lateral spreading could impact the bridge embankments and could place additional loads on the bridge foundations. The potential for lateral spreading will need to be evaluated at both the north and south slopes and, if necessary, lateral spreading hazards should be mitigated. Typically, lateral spreading and liquefaction settlement mitigation can be addressed together with either ground improvement, deep foundations, or a combination of both. Bridge Foundations: The bridge abutment foundations could be constructed as shallow footings supported on properly prepared bearing surfaces, or as deep foundations. We anticipate that alluvial soils will be present below the north and south abutments. Alluvium below the bridge abutments will be susceptible to liquefaction. Shallow foundations are more susceptible to liquefaction -induced settlement than deep foundation and, therefore, will likely require significant ground improvement to be a feasible option. Based on our experience, deep foundations are generally the preferred and most economical alternative for bridges constructed on alluvial soils, similar to those in the vicinity of the 48th Avenue South Bridge. Deep foundations typically provide high load capacities and better seismic performance in loose alluvial soil sites when compared to shallow foundations. However, if bedrock is encountered at a shallow depth near the north approach and abutment, shallow foundations bearing on bedrock could provide adequate support. Bedrock would provide ample bearing resistance for shallow foundations and will not settle under static loading. Both driven piles and drilled shafts are expected to be feasible deep foundation alternatives. Drilled shafts are more common for bridge foundation support in alluvial soils. In our experience a typical 4-foot-diameter drilled shaft can achieve a strength resistance value between 500 to 600 kips at a depth of 80 feet. Drilled shafts would likely need to be installed using casings or with drilling slurry to support the whole sidewalls in loose sand saturated alluvial soils. The feasibility or constructability of deep foundations will depend on the depth to bedrock. If the bedrock is relatively shallow (10 to 20 feet below ground surface) the shafts can achieve high axial and lateral resistances by socketing the shafts into the rock 5 to 15 feet. Similarly, rock socketing the shafts will also likely be necessary if bedrock is encountered in the 20- to 50-foot depth range. Socketing the shafts into rock at this depth can be more difficult than shallow rock sockets. Installing drilled shafts foundations into GEOENGINEERS...0 June 2, 2016 Page 20 File No 0259 055.00 rock is a specialized construction technique and often requires specialized drilling equipment compared to typical equipment where rock is not present. The rock is reported to be partially fractured and drilling into fractured rock can cause large pieces of rock to dislodge from the sidewalls and seize the drill tooling. In a deep rock socket scenario increased risk associated with construction schedule and costs should be anticipated. If bedrock is present in the 20-to 50-foot range, driven pipe piles may become a preferred alternative over the riskier installation of deep rock sockets. Driven piles bearing on hard rock can achieve axial capacities on the order of the structural capacity of the pile. Special pile driving shoes/equipment may be required in order to drive the pile into the rock. Steel or concrete driven piles are both likely feasible for constructing the 48Lh Avenue South Bridge. Steel piles could be installed using either vibratory or impact hammers, concrete piles would require installation with an impact hammer. If bridge structure foundations are supported on deep foundations, the piles or shafts would need to be designed to resist liquefaction -induced downdrag loads and lateral spreading loads. If shallow foundations are used, the existing loose (or soft) alluvial soils would need to be improved to increase the bearing capacity, mitigate for liquefaction and lateral spreading and to remediate static settlement issues. Remediation techniques such as earthquake drains, vibratory replacement and compaction (stone columns), or jet grouting are possible alternatives. Generally, stone columns in alluvial soils extend to depths between 30 and 50 feet below ground surface. Stone columns are generally installed below the entire foundation/abutment and extend about 5 to 10 feet outside of the foundation/abutment footprint. In our experience design displacement ratios on the order of 7 to 10 percent are common for stone columns in alluvial soils. Constructability of shallow foundations will also be affected by shallow groundwater levels, dewatering may be required. In the area of the north abutment, there is an overhead clearance restriction due to the South 129th Street elevated roadway. Tall ground improvement rigs may not be capable of working below the elevated roadway and alternative methods may be necessary in order to accommodate the clearance restrictions. We do not anticipate that overhead clearance will be an issue in the south abutment area. Constructability of shallow foundations will also be affected by shallow groundwater levels and may require the foundation area to be dewatered. Approach Embankments and Retaining Walls: Bridge approaches could be constructed as earth embankments or as elevated viaducts. Earth embankments would need to be founded on suitable subgrade soils. In order to reduce the width of the approach embankments, retaining walls, engineered slopes, or MSE walls may be required to stabilize the edges of the embankment prism. Large area fills such as approach embankments can cause settlement. If highly compressible soils are present below approach embankment areas, they may need to be remediated. Remediation could involve removal and replacement, pre -loading and surcharging, or ground improvement. If earth embankments will be designed to withstand the design earthquake, ground improvement will likely be required where embankments are taller than about 6 to 8 feet. Stone columns are commonly used as a ground improvement technique and would be generally be constructed similar to those described previously. GEOENGINEERSg June 2, 2016 Page 21 File No 0259.055 00 Retaining walls could be incorporated into the design of the approach embankments, bridge abutments, and slope stabilization configuration. Retaining walls would help limit the footprint of the approach embankment and abutments. Conventional cast -in -place walls or MSE walls could be used. More specialized wall types such as soldier pile walls are also feasible. If retaining walls are considered to help address slope stability and erosion issues, we anticipate that soldier pile walls or other specialized wall types will need to be considered due to layout restrictions as conventional wall types may not be feasible due to their footprint and constructability considerations such as shallow groundwater and work space limitations. Bridge approaches could also be constructed as elevated viaducts. Typically, this alternative is more expensive than constructing an earth embankment approach because it requires the construction of foundations and an elevated roadway. If the approaches are constructed as elevated viaducts, foundation types similar to those described in the "Bridge Foundations" section above can be considered. LIMITATIONS We have prepared this report for David Evans and Associates, Inc. for the City of Tukwila - BNSF Intermodal Yard Facility Access located in Tukwila, Washington. David Evans and Associates, Inc. may distribute copies of this report to owner's authorized agents and regulatory agencies as may be required for the Project. Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices for geotechnical engineering in this area at the time this report was prepared. The conclusions, recommendations, and opinions presented in this report are based on our professional knowledge, judgment and experience. No warranty, express or implied, applies to the services or this report. Please refer to Appendix A titled "Report Limitations and Guidelines for Us& for additional information pertaining to use of this report. REFERENCES Booth, D. and Waldron, H., "Geologic Map of the Des Moines 7.5' Quadrangle, King County, Washington, U.S. Geological Survey, 2004. City of Tukwila Sensitive Areas Map, htto://tukwilawa.gov/citmaos.html, Accessed September 28, 2015. Converse Consultants NW, "Geotechnical Design Summary Report Task 219 - Southern Transfer/ Interurban Project, Tukwila, Washington", March 1, 1993. Jones Bassi and Associates, "Police Training Academy Report" February, 1974. Palmer, S. and Others, "Liquefaction Susceptibility Map of King County, Washington, Washington Department of Natural Resources, September, 2004. Palmer, S. and Others, "Site Class Map of King County, Washington, Washington Department of Natural Resources, September, 2004. GEOENGINEERSI June 2, 2016 Page 22 File No. 0259.055.00 Shannon and Wilson, Inc., "Landslide Investigation Seattle -Tacoma Freeway Vicinity of Station 2670", May 10, 1968. Soil Sampling Service, "Report on Foundation Investigation Boeing Access Road Undercrossing at Seattle, Washington" February, 1964. Troost, K. and Others, "The Geologic Map of Seattle - A Progress Report" U.S. Geological Survey, 2005. GEOENGINEERSQ June 2, 20161 Page 23 File No, 0259.055.00 \0259055\GIS\MXDS\025905500 T0100_FLSItes8x11.mxd Date Exported: 06/02/16 by cehelf 1171h S. Alternativerl Legend Access Alternatives Notes: 1. The locations of all features shown are approximate. 2. This drawings for information purposes. It is intended to assist in showing features discussed In an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic f les. The master file Is stored by GeoEngineers, Inc. and will serve as the official record of this communication. Data Source: Streets map from Mapbox 2015 Project on: NAD 1983 UTM Zone 10N 2,000 0 2,000 Feet Access Alternatives City of Tukwila - BNSF Intermodal Yard Facility Access Tukwila, Washin:ton GEOENGINEERS Figure 1 ri Notes: 0 1. The locations of all features shown are approximate. 2. This draw ng is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master f.le is stored by GeoEng.neers. Inc. and will serve as the official record of this communication. 3. For a complete list of the geologic units and symbols shown on this figure see 'Geologic Map of Seattle - A Progress Report' Toost and Others. 2005. Data Source: Geology from USGS, Streets from ESRI 2014 Projection: NAD 1983 UTM Zone 1ON Legend Qal - Alluvium Qvt - Vashon Till (glacial deposit) - Qp - Pre Vashon glacial deposit Tpt-Tukwila Formation (bedrock) \ �4 1,000 0 1,000 Feet Northern Access Alternatives City of Tukwila - BNSF Intermodal Yard Facility Access Tukwila, Washington GEOENGINEERS Figure 2 Notes: 1. The locations of all features shown are approximate. 2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication. 3. For a complete list of the geologic units and symbols shown on this figure see "Geologic Map of The Des Moines 7.5' Quadrangle, King County, Washington. Booth and Weldon, 2004. Data Source: Geology from LSGS, Streets from ESRI 2014 Projection: NAD 1983 UTM Zone 1ON Legend Qal • Alluvium Qvt-Vashon Till (glacial deposit) Qp - Pre Vashon glacial deposit Tpt - Tukwila Formation (bedrock) Earlinglon Park _ 1,000 0 1,000 Feet Southern Access Alternatives City of Tukwila - 9NSF Intermodal Yard Facility Access Tukwila, Washington GEOENGINEERS„dg Figure 3 P:10\0259055,Enveonmental\0259055-00 FO4-ffR ri-g TAB:F04 Date Exported: 06/03/16. 93513y cvanslyke Proposed Route Alignment Notes: 1. The locations of all features shown are approximate. 2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication. Data Source: Aerial from Bing Maps dated 10/2014. Alignment by David Evans and Associates, 6/25/15. Bedrock Area Wetlands Area South Boeing Access Road Overpass -3 �,." , _ 5. }-• Airport Way Alternative City of Tukwila - BNSF Intermodal Yard Facility Access Tukwila, Washington GEOENGINEERS Figure 4 P,\0\0259055\CAD\00\Envuonmental\026905500 F04-F08.owg TAB.F05 Date Exported:06/03/16- 9 35 by riaiwyxe Notes: 1. The locations of all features shown are approximate. 2. This drawing is for information purposes. It Is intended to assist in showing features discussed in an attached document. GeoEngineers. Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication. Data Source: Aerial from Bing Maps dated 10/2014. Alignment by David Evans and Associates, 6/25/15. 300 0 l nC • Proposed Rout: Alignment 300 Feet Above Ground Water Line Bedrock Area • South 112th Street Alternative City of Tukwila - BNSF Intermodal Yard Facility Access Tukwila, Washington GEOENGINEERS Figure 5 P:L0\025905b .environmental \0259055-00 F04F08.uwg 1A8F06 Date Exported:06/03/16 • „ bv...:msiyke Zrs 4 � -:4 as'a. Wit . South 124.th Street Nctes: 1. The locations of all features shown are approximate. 2. This drawing is for information purposes. It is intended to assist in showing features discussed In an attached document. GecEngineeis, Inc. cannot guarantee the accuracy and content of electronic files. Tne master file is stored by GeoEn_ineers, Inc. and wili serve es the official record of this communication. Bata Source: Aerial from Bing Maps dated 10/2014. Alignment by David Evans and Associates. 6/25/15. 300 0 roposed Route Aiigruneni • • 300 South 124th Street Alternative City of Tukwila - BNSF Interrnodal Yard Facii,ity Access Tukwila, kwila, Washington GEOENGENEERSfi Figure 6