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HomeMy WebLinkAboutSWP272757(1) ' City of Renton Planning/Building/Public Works FINAL ENVIRONMENTAL IMPACT lag STATEMENT g Oakesdale Avenue S.W c S.W. 16th to S.W. 31 st Street Renton, Washington Zza i , rtiryi 'ter, �x July 1997 2-4 Oakesdale Avenue S.W. R/W R/W a5' a5' ULTIMATE 3 n'-- --L-- 5' DIMENSIONS a• 5'81KE� t7 CENTER TURN I 11 TI1 91E 4 LANE LANE OR MEDIAN I I LANNE 7, INTERIM SHOO ER DIMENSIONS a- 8' � 12' � 12' � 12' � a'� PHASE 2 CONSTRUCTION i EXISTING ZGRAOE 0 0 EXISTING GRADE TYPICAL SECTION S.W.27TH ST.TO S.W.19TH ST. 1.5' 6.5' S'---- 11' 11' 12--U 11' 11' 5'--6.5'— --1.5' 81KE MEDIAN BIKE LANE LANE i i 1 75'-2" 11 SPACES AT 6'-10- TYPICAL BRIDGE SECTION Post-ItT'brand fax transmittal memo 7671 #of pages ► 2 �/ AT SPRNWROOK CREFEK To pA T C I I V E f 1—L From L I W1 LZ6�,� iv , Co. L-�/S� T Co. �a-1 Dept. T. I Phone A —TYPICAL ROADWAY CROSS SECTIONS ax 57 # �LS 2�L —��2� City of Renton FE IS R/W R/W 45' 45' i BIKE BIKE LANE LANE 0 EXIS TING GRADE EXISTING/ GRADE TYPICAL ROADWAY SECTION (PHASE 2) SOUTH OF S.W.2771-1 ST. R/W R/W 45 4$' i BIKE CENTER TURN 78KE LANE LANE OR MEDIAN i EXISTING �GRADE — OR G —— 0 .&TO& 2003 Western Avenue TYPICAL SECTION WARREN 555MarketPlaccone S.W.19TH ST.TO S.W.16TH ST. 8121 INCORPORATED Seattle. -- 300 (2D8)44B-4200 FIGURE 2.2.2-2 REFINED ALTERNATIVE 1 1 Oakesdale Avenue S .W. S.W. 16th Street to S.W. 31 st Street 1 Final Environmental Impact Statement July 1997 1 1 1 ■ 1 i 1 1 Prepared by: ' City of Renton Planning/Building/Public Works 200 Mill Avenue S. ' Renton, Washington 98055 1 Final Environmental Impact Statement Fact Sheet Fact Sheet ' Title Oakesdale Avenue S.W., S.W. 16th Street to S.W. 31st Street Description of proposal The proposal is the construction of approximately one mile of four to ' and alternatives five lanes of arterial roadway with sidewalks, drainage system, and illumination to connect the existing Oakesdale Avenue S.W. at S.W. 16th Street to Oakesdale Avenue S.W. at S.W. 31st Street — ' presently a cul-de-sac. The proposed project includes a bridge crossing of Springbrook Creek and wetlands south of S.W. 16th Street, and a bridge crossing of City-owned wetlands south of S.W. 27th Street. The project is proposed for phased construction: the initial phase includes the Springbrook Creek and wetland bridge and a three-quarter mile long roadway between S.W. 16th Street and S.W. 27th Street. The second phase is one-quarter mile long between S.W. 27th and S.W. 31st Streets and includes the wetland bridge. Two alternative routes (alignments) for the proposed roadway and a ' no action alternative are analyzed in this draft environmental impact statement. ' Alternative A (Preferred Alignment). This alternative alignment locates Phase 1 of the proposed project within the Boeing Company's Longacres property as shown in the Longacres Office Park master plan (Draft Environmental Impact Statement, August 1994, and Final Environmental Impact Statement, March 1995). The Phase 2 project segment is a direct connection between the Phase I project terminus and existing Oakesdale Avenue S.W. at S.W. 31st Street (see Alignment Alternatives, Figure 1.3-1). Comments received on the DEIS, additional study and discussins with government agencies has resulted in refinements to the alternative alignment to further reduce environmental impact of the proposed project. (See Figure 2.2.2-1.) Alternative C. This alternative locates the Phase 1 segment of the proposed project on the eastern property line of the proposed Boeing Company Longacres Office Park. The proposed roadway alignment curves to the southwest to rejoin the Alternative A alignment north of S.W. 27th Street (see Alignment Alternatives, Figure 1.3-1). The Phase 2 alignment is the same as Alternative A. ' No Action. Under this alternative, the existing gap in the Oakesdale Avenue S.W. corridor would remain. There would be no public through access on the Oakesdale Avenue S.W. corridor between S.W. 16th and S.W. 27th Streets and between S.W. 27th and S.W. 31st Streets. Property owners abutting this missing segment of the Oakesdale Avenue S.W. corridor would need to provide private roadways to connect to the public arterial system. Location of site East one-half of sections 24 and 25, T23N, R4E. The north-south alignment is parallel to and approximately 2,300 feet west of Lind ii City of Renton ' Fact Sheet Oakesdale Avenue S.W. Avenue SW and connects existing sections of Oakesdale Avenue , S.W. presently terminating at S.W. 16th Street on the north and S.W. , 31st Street on the south (see Project Vicinity Map, Figure 1). Proposal's sponsor City of Renton Date of implementation Phase 1 construction would be in 1998-99. Phase 2 construction is ' not presently programmed. Lead Agency City of Renton Planning/Building/Public Work Department , Responsible official City of Renton Planning/Building/Public Works Department 200 Mill Avenue South Renton, WA 98055 (425)235-2550 List of possible permit, U.S. Army Corps of Engineers approval, and license Section 404 Clean Water Act requirements Washington Department of Ecology 401 Certification, Clean Water Act National Pollutant Discharge Elimination System (NPDES) Washington Department of Fish and Wildlife Hydraulic Project Approval (HPA) , City of Renton Clearing and grading permit Conditional use permit Shoreline substantial development permit Utility Agreements Seattle Water Department ' Drainage District No. 1 Puget Sound Energy Olympic Pipeline Company Authors and principal HNTB Corporation. contributors to EIS 600 108th Avenue N.E., Suite 405 Bellevue, WA 98004 (425)455-3555 INCA Engineers Inc. 11120 N.E. 2nd Street Bellevue, WA 98004 (425) 450-0933 Osborn Pacific Group Inc. 2025 First Avenue 930 Market Place Tower ' Seattle, WA 98121-2100 (206)448-7956 Final Environmental Impact Statement Fact Sheet Shapiro & Associates, Inc. ' 1201 3rd Avenue, Suite 1700Seattle, WA 98101 (206) 624-9190 Woodward Clyde Consultants 1500 Century Square 1501 Fourth Avenue Seattle, WA 98101-1662 (206)343-7933 Kato & Warren 2001 Western Avenue 555 Market Place One Seattle, Washington 98121 Draft EIS issue date April 7, 1997 Final EIS issue date July 7, 1997 ' Subsequent environmental Phase 2 may require additional SEPA review prior to review implementation. Location of background City of Renton information Planning/Building/Public Works Department 200 Mill Avenue South Renton, WA 98055 (425)235-2550 Cost of copy to public Final EIS $10.00 ' iv Final Environmental Impact Statement Table of Contents Distribution List Federal Agencies U.S. Army Corps of Engineers ' Seattle District Office Engineering Division- Planning 1 U.S. Department of Agriculture Resource Conservation Services Renton Field Office U.S. Department of HUD Mr.Nishimura U.S. Department of Transportation Department of Highways District 1 U.S. Environmental Protection Agency ' Jerry Opatz Native American Tribes ' Duwamish Tribal Offices Muckleshoot Indian Tribe Rod Malcomb, Fisheries State Agencies Department of Natural Resources ' Puget Sound Water Quality Authority Abbot Raphael Hall ' SEPA Register Washington Department of Ecology Environmental Review State Department of Ecology Environmental Review Section Northwest Regional Office 1 State Department of Ecology Shorelands- Permit Coordinator Washington Department of Fish and Wildlife Larry Fisher Phil Schneider Washington State Department of Transportation ' District 1 Washington State Energy Office Judith Merchant, Director Regional Agencies Greater Renton Chamber of Commerce v ' Final Environmental Impact Statement Distribution List Puget Sound Air Pollution Control Agency ' Puget Sound Regional Council Seattle-King County Health Services Department Local Agencies ' King County Department of Development and Environmental Services Land Use Services Division King County Department of Natural Resources Surface Water Management Division ' King County Department of Transportation Transportation Planning Division King County Department of Natural Resources Environmental Planning and Real Estate Section ' King County Soil Conservation King County Conservation District ' Jack Davis King County Courthouse EIS Review Coordinator King County Drainage District No. 1 Seattle Public Utilities , Water Department City Agencies (City of Renton) ' Mayor City Council City Attorney ' Fire Department Police Department Parks& Recreation Planning Commission Utilities/Services Puget Sound Energy ' Olympic Pipeline Company Libraries , Renton Public Library Main Branch ' Renton Public Library Highlands Branch vi Final Environmental Impact Statement Table of Contents ' Other Public and Private Organizations City of Kent City of Tukwila Valley Medical Center Washington Environmental Council ' Darlene Madenwald Media Valley Daily News vii City of Renton FEIS Oakesdale Avenue S.W. ' TABLE OF CONTENTS 1. SUMMARY.......................................................................................................................................................... 1-1 ' 1.1 INTRODUCTION AND BACKGROUND ......................................................................................................... 1-1 1.2 HISTORY AND PURPOSE OF THE PROPOSED PROJECT............................................................................. 1- 1.2.1 Project History............................................................................................................................... 1-1 ' 1.2.2 Purpose of the Project................................................................................................................... 1-2 1.3 ALTERNATIVES............................. ............... 1-2 .............................................................................. 1.3.1 Alternative A.................................................................................................................................. 1-5 1.3.2 Alternative C.................................................................................................................................. 1-5 1.3.3 No Action Alternative..................................................................................................................... 1-6 1.3.4 Preferred Alternative..................................................................................................................... 1-6 ' 1.4 ISSUES TO BE RESOLVED....................................................................................................................... 1-6 1.5 SIGNIFICANT IMPACTS, MITIGATION MEASURES, AND UNAVOIDABLE ADVERSE IMPACTS ........................... 1-6 2. ADDITIONAL INFORMATION.......................................................................................................................2-1 2.1 INTRODUCTION....................................................................................................................................... 2-1 2.2 ALTERNATIVES....................................................................................................................................... 2-1 2.2.1 Selection of the Preferred Alternative............................................................................................ 2-1 ' 2.2.2 Alternative A - The Preferred Alternative ...................................................................................... 2-1 2.2.3 Construction Sequencing.............................................................................................................. 2-3 2.3 AFFECTED ENVIRONMENT, IMPACTS, AND MITIGATION............................................................................. 2-5 2.3.1 Air Quality...................................................................................................................................... 2-5 2.3.2 Noise............................................................................................................................................. 2-5 2.3.3 Geology and Soils...........................................................................................................*............. 2-5 2.3.4 Surface Water Quantity/Quality..................................................................................................... 2-5 ' 2.3.5 Wetlands..................................................................................................................................... 2-15 2.3.6 Wildlife, Vegetation, and Fisheries.............................................................................................. 2-20 2.3.7 Land and Shoreline Use.............................................................................................................. 2-23 2.3.8 Social Elements........................................................................................................................... 2-25 2.3.9 Transportation............................................................................................................................. 2-28 2.3.10 Parks and Recreation................................................................................................................ 2-28 2.3.11 Visual Resources...................................................................................................................... 2-29 ' 2.3.12 Historic and Cultural Resources................................................................................................ 2-30 2.3.13 Hazardous Materials..........................................................................................._.................... 2-30 3. COMMENTS AND RESPONSES......................................................................................................................3-1 viii ' Final Environmental Impact Statement Table of Contents LIST OF TABLES ' TABLE 1.5-1 SIGNIFICANT IMPACTS, MITIGATION MEASURES, AND UNAVOIDABLE ADVERSE IMPACTS............. 1-7 TABLE 2.3.3-1 EXCAVATION AND FILL QUANTITIES(CUBIC YARDS).....................................................................2-5 , TABLE 2.3.4-1 INCREASE IN IMPERVIOUS SURFACE(ACRES)..................................................................................2-7 TABLE 2.3.4-2 FLOODPLAIN STORAGE IMPACTS...................................................................................................2-1 O TABLE 2.3.5-1 CALCULATION OF WETLAND AREA FILLED OR SHADED...............................................................2-18 , TABLE 2.3.5-2 WETLAND REPLACEMENT FOR REFINED ALTERNATIVE A............................................................2-19 TABLE 2.3.6-1 ESTIMATED HABITAT LOSS............................................................................................................2-22 TABLE 2.3.7-1 LAND ACQUISITION REQUIREMENTS(ACRES)...............................................................................2-24 LIST OF FIGURES FIGURE 1-1. PROJECT VICINITY........................................................................................................................... 1-1 FIGURE 1.3-1 ALTERNATIVE ALIGNMENTS.......................................................................................................... 1-3 FIGURE 1.3-2 TYPICAL CROSS SECTIONS.............................................................................................................. 1-4 FIGURE 2.2.2-1 REFINED ALTERNATIVE A ALIGNMENT..........................................................................................2-2 , FIGURE 2.2 2-2 REFINED ALTERNATIVE A ALIGNMENT— TYPICAL CROSS SECTIONS..........................................2-4 FIGURE 2.3.4-1 REFINED ALTERNATIVE A DRAINAGE SYSTEMS............................................................................2-8 FIGURE2.3.5-1 DELINEATED WETLANDS ...........................................................................................................2-17 ' City of Renton ix FEIS Oakesdale Avenue S.W. Foreword This Final Environmental Impact Statement (FEIS) has been prepared to comply with the State Environmental Policy Act(SEPA Chapter 43.21C RCW), and the City of Renton's SEPA Policy. ' A Draft Environmental Impact Statement (DEIS) for the City of Renton's proposed Oakesdale Avenue S.W. Extension Project -- S.W. 16th Street to S.W. 31st Street was published on April 7, 1997 and ' distributed to federal and state agencies, to Native American tribes, and to a variety of local agencies and interest groups (see Distribution List on page iv of the FEIS). The thirty day review/comment period ended on May 6, 1997. Written comments were received from two State agencies, City of Seattle Public Utilities, City of Renton Community Services, and Friends of Black River (a local ad hoc group of citizens). In addition to the Fact Sheet, Distribution List and this Foreword, this FEIS includes Chapter 1 - Summary; Chapter 2 - Additional Information; and Chapter 3 - Comments and Responses. Based on comments received on the DEIS, discussions with government agencies, and additional studies ' investigating ways to minimize impacts of the project (and reduce the project cost), refinements have been made to Alternative A (the Preferred Alternative). A description of impacts on the affected environment and modifications to mitigation measures, where appropriate, as a result of the refinements to Alternative A are included in Chapter 2. FEIS Process and Schedule Following issuance of this FEIS, the City will prepare a Mitigation Document which will set forth the mitigation measures for the project. t Final Environmental Impact Statement 1-1 Summary 1 . Summary 1.1 Introduction and Background The City of Renton proposes to acquire right-of-way for and construct a one-mile section of arterial �Rg°° sWs��s \, roadway. Figure 1-1 (Project Vicinity map) shows 'm -X the proposed project in relationship to the existing — _ ", 0akesq� -Begin roads in the area. The project will begin at the �� s�,. Project existing intersection of S.W. 16th Street with A, ` yea �`��; Oakesdale Avenue S.W. and end at existing Tukwila � ; 0 Oakesdale Avenue S.W. at S.W. 31st Street. The � 405:BNB Renton roadway (including travel lanes and turn lanes) would vary from four to five lanes in width. The project F Pro ec(1 Snander BNd SW 27 St___ would include sidewalks, bicycle lanes, traffic control �--------- — � a devices (stop signs and/or traffic signals), m �m landscaping, lighting, and drainage facilities. The — '. N-sw 34thsc__> ' typical right-of-way width is expected to be 90 feet. " At this time the proposed right-of--way corridor _ a+3 ._SW_41st includes some privately owned properties and s,eahst p; °�W41_;St{ i m property owned by the City of Renton. Kent The project would be constructed in two phases. The O initial phase would connect between S.W. 16th Street and S.W. 27th Street, a distance of about three- ° . 14--'2 Miles Q quarters of a mile. The second phase of the project ' would be about one-quarter mile in length. FIGURE 1-1PROJECT VICINITY Preliminary investigation by the City and their environmental consultant has narrowed the location (i.e., alignment) of the new proposed roadway to two ' alternatives. The City of Renton issued a declaration of significance for this project and conducted a public scoping process. A scoping meeting was held on March 16, 1995 at 7:00 p.m. at the Renton Community Center, 1715 Maple Valley Highway. The comment period on scoping issues ended on March 27, 1995. Following the public scoping period, the specific alternatives to be included in the environmental impact ' statement (EIS) were confirmed by the City. Evaluation in the EIS focuses on potentially significant environmental impacts from both building and operating the new section of Oakesdale Avenue S.W. The Draft Environmental Impact Statement (DEIS) addresses the impacts of the roadway and bridge project as called for by SEPA and presents mitigation measures where needed. 1.2 History and Purpose of the Propose Project 1.2.1 Project History ' Planning for Oakesdale Avenue S.W. between S.W. 16th and 31st Streets began in 1980 with the Valley Parkway S.W., S.W. 43rd Street to Empire Way S, Advance Planning Study Report prepared for the City of Renton. At the time this study was conducted in 1980 to 1982, the most southerly two blocks of the City of Renton 1-2 , FEIS Oakesdale Avenue S.W. the route, between S.W. 43rd Street and S.W. 41st Street, had been constructed with abutting industrial park development. Subsequent to the 1992 study, Oakesdale Avenue S.W. was constructed between S.W. 41st and S.W. 31st Street as adjacent industrial parcels have developed, and the northern section of the route has been completed between Monster Road and S.W. 16th Street. The one-mile section between S.W. 16th and S.W. 31st Streets remains the only undeveloped section of the project recommended in the 1982 report. , The Advance Planning Study also recommended an alignment for S.W. 27th Street between East Valley Highway and West Valley Highway at Strander Boulevard. This road would intersect with the recommended Oakesdale Avenue S.W. alignment. At the time of the 1980-1982 study, the portion of S.W. 27th Street east of the Boeing Longacres Office Park property was in design, and construction was completed in 1982. There are no current plans to extend S.W. 27th Street as a public road west of the proposed Oakesdale Avenue S.W. alignments. ' 1.2.2 Purpose of the Project The Oakesdale Avenue S.W. project is one of the planned arterial system improvements (Arterial Plan) , identified by the City of Renton as mitigation for the Land Use Element of the adopted Comprehensive Plan (1995). The Arterial Plan was developed to provide a roadway system that will meet the year 2010 ' level of service standard and be concurrent with year 2010 land use development. Along the proposed project corridor, proposed development includes the 10,000-employee Longacres Office Park site. The proposed Oakesdale Avenue S.W. project would have the following purposes: ' • increase the person-carrying capacity of the Renton Valley arterial system by the construction of improvements and the implementation of actions that support single-occupant vehicle (SOV), high- ' occupant vehicle (HOV), and transit modes of travel; • maintain, enhance, and increase pedestrian and bicycle travel by providing both safe and convenient routes for the commuting and recreating public; and ' • support land use, neighborhood, and business goals, and improve safety. 1.3 Alternatives Two build alternatives (Alternatives A and C) and the No Action Alternative (as specified by SEPA ' rules) are analyzed in this EIS for the Oakesdale Avenue S.W. project. The location of the two build alternatives are identified in Figure 1.3-1. For project impact analysis, two bridge structures (one crossing Springbrook Creek and constructed , wetlands on Boeing CSTC property at the north end of the project, and the second crossing existing wetlands south of S.W. 27th Street) were assumed for each of the build alternatives. The typical cross- sections shown in Figure 1.3-2 were used for both build alternatives. The build alternatives provide four ' travel lanes (two in each direction) for the full length of the project. Between S.W. 16th Street and S.W. 27th Streets, a center turn lane/median would be provided to allow separated left turn movements at the intersections of S.W. 16th Street and S.W. 27th Street, and at other locations that may be approved in the future as abutting property is developed. South of S.W. 27th Street, the center turn-lane median would be dropped providing four travel lanes. Bicycle lanes on the outside (right-hand) of the motor vehicle travel lanes and sidewalks on both sides of the new roadway would be provided the full project length. ' The proposed project would also include roadway pavement, curbs, gutters, street lighting, landscaping, roadway drainage facilities(including detention and treatment) and traffic signals (when warranted)at H d - � MUM° �VI�.1,6th� Benaro�a � � prop r a~ ",Boeing,1_7 sites ' US C a:_ gyp. � tMy>{• � Proposed ; perfy ��y t Longacres �. •; r 'Office Park rd 5 ,+ 9 �u its P,has"=127t V I Phase 2' CL End project � } 200<400 800 Feet City of Renton 1-4 , FEIS Oakesdale Avenue S.W. FIGURE 1.3-2 TYPICAL CROSS SECTIONS ' q ROADWAY&RIGHT OF WAY 90'RIGHT OF WAY , 6' 6' 5' 11' 11' 10' - 12' 11' 11, 5' 6' 6' SIDEWALK PUNT IKE LANE LANE MEDIAN OR LANE LANE BIKE- ANT SIDEWALK ' STRIP LANE TURN UNE LANE I STRIP TYPICAL ROADWAY SECTION , q ROADWAY k RIGHT OF WAY , 82' 79' ' 6.5' S' if' 12' 10' 12" 11' S' 6.5' SIDEWALKI BIKE LANE LANE MEDIAN LANE LANE BIKE I SIDEWALK LANE LANE i GROUND , PILES (TIP.) , NORTH BRIDGE TYPICAL SECTION q ROADWAY&RIGHT OF WAY 7 6r 6.5' 5' 11' 11' 11' 11' S' 6.5' DEWALX BIKE LANE UNE UNE LANE BIKE SIDEWA ' LANE LANE i GROUND PILES (TIP.) ' SOUTH BRIDGE TYPICAL SECTION ' Final Environmental Impact Statement 1-5 Summary ' S.W. 16th Street and at S.W. 27th Street. Access to abutting properties would be determined in the permitting and approval of abutting development. The proposed project would be constructed in two phases: Phase 1, from S.W. 16th Street to S.W. 27th Street; and Phase 2, from S.W. 27th Street to S.W. 3l st Street. Impacts and mitigation measures associated with each phase of the project have been addressed, when appropriate, for each of the build alternatives. 1.3.1 Alternative A Beginning at the existing Oakesdale Avenue S.W. and S.W. 16th intersection, the alignment curves to the southwest through Benaroya Company (former Group Health) property, crosses Springbrook Creek about 400 feet south of S.W. 16th Street, and enters the Boeing Customer Service Training Center (CSTC) property. The alignment then curves to the southeast through the CSTC property and enters the Boeing Company Longacres Office Park property on a southerly bearing at S.W. 19th Street. The alignment extends south through the Longacres Office Park property to approximately 1,000 feet north of SW 27th Street. From this point, the alignment continues south to S.W. 27th Street along the Longacres ' Office Park east property line (City of Renton west property line). South of S.W. 27th Street, the alignment continues south on City of Renton property to join existing Oakesdale Avenue S.W. at S.W. 31 st Street. An approximately 400-foot long structure is proposed for the north bridge crossing Springbrook Creek and the CSTC Boeing constructed wetlands, and a 600-foot long structure is proposed for the south bridge crossing wetlands south of S.W. 27th Street. Typical right-of-way width for the project would be 90 feet. Total right-of-way required for Alternative A would be 9.7 acres for construction of Phase 1 between S.W. 16th and S.W. 27th Streets, and 2.4 acres ' for construction of Phase 2 between S.W. 27th and 31st Streets. An additional 0.6-acre would be required for permanent easements along the Phase 1 portion of the project. 1.3.2 Alternative C The alignment of Alternative C begins at the existing Oakesdale Avenue S.W. and S.W. 16th Street intersection, continues in a south-southeasterly direction through the Benaroya Company (former Group Health) property before turning south to cross Springbrook Creek about 800 feet south of S.W. 16th Street and pass through the Boeing Company CSTC property. The alignment then continues due south along the Longacres Office Park east property line for about 800 feet, where the alignment curves to the southwest to join the Alternative A alignment approximately 900 feet north of S.W. 27th Street. From this point, the Alternative C alignment coincides with the Alternative A alignment continuing south to S.W. 3 I st Street. An approximately 540-foot long structure is proposed for the north bridge crossing Springbrook Creek and the Boeing CSTC constructed wetlands, and a 600-foot long structure is proposed for the south bridge crossing wetlands south of S.W. 27th Street. Typical right-of-way width for the project would be 90 feet. Total right-of-way required for Alternative ' C would be 11.2 acres for construction of Phase 1 between S.W. 16th and S.W. 27th Streets, and 2.4 acres for construction of Phase 2 between S.W. 27th and 31st Streets. An additional 0.3-acre would be required for permanent easements along the Phase 1 portion of the project. City of Renton 1-6 , FEIS Oakesdale Avenue S.W. 1.3.3 No Action Alternative , The No Action Alternative will be carried through this DEIS to provide a baseline point for comparison of Action Alternatives. Under this alternative, the existing gap in the Oakesdale Avenue S.W. corridor between S.W. 16th Street and S.W. 27th Street would remain. The No Action Alternative assumes that other roadway system (arterial, HOV, bicycle, and pedestrian) ' and transit service improvements planned for the Renton Valley area (described in Section 3.9, Transportation) would be in place by the year 2010. Access to properties abutting this missing segment of the Oakesdale Avenue S.W. corridor is assumed to be provided by private road connections to both ' S.W. 16th Street and S.W. 27th Street. Developer and City of Renton-initiated transportation demand management (TDM) programs in support of City of Renton policies and Commute Trip Reduction legislation are assumed to continue or be augmented under the No Action Alternative. ' 1.3.4 Preferred Alternative After review of the potential significant impacts and mitigation requirements, and comments received , from circulation of the DEIS, Alternative A is the City of Renton's preferred alternative. Alternative A provides the most direct route with the least environmental impact. Based on comments received on the DEIS, discussions with the U.S. Army Corps of Engineers and other ' government agencies, and recommendations of a Value Engineering Study to investigate options for reducing the cost of the proposed project, refinements have been made to the Preferred Alternative (Alternative A) to further minimize this alternative's impacts on the environment. A description of these ' refinements, and additional information on existing conditions, significant impacts and mitigation measures related to the refined Alternative A, are presented in Section 2, Additional Information. 1.4 Issues to Be Resolved SEPA Rule WAC 197-11-440 states that the EIS summary shall include a discussion of any issue to be ' resolved relative to the proposed action and alternatives. No such issues have been identified. 1.5 Significant Impacts, Mitigation Measures, and Unavoidable Adverse Impacts Table 1.5-1 summarizes the impacts, mitigation measures, and significant unavoidable adverse impacts for each of the alternatives. The number in parentheses after each environmental element refer to the corresponding section number in Chapter 3 of the DEIS. Final Environmental Impact Statement 1-7 Oikesdale Avenue S.W. TABLE 1.5-1 SIGNIFICANT IMPACTS, MITIGATION MEASURES, AND UNAVOIDABLE ADVERSE IMPACTS Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0) Optional Adverse Impacts (0) Optional Adverse Impacts AIR QUALITY (3.1) AIR QUALITY(2.3.1) Alternative A, Phases 1 and 2 Construction activities Comply with the City of None. Same as DEIS Same as DEIS Same as DEIS would increase Renton Mining, particulate emissions Excavation and Grading and other pollutants in Ordinance (Title IV, City the project vicinity. of Renton Building Regu- lations, Chapter 10), the King County Surface Water Design Manual as adopted by the City of Renton, and PSAPCA Regulation I, Section 9.15 regarding fugitive dust control, and odor control. (R) NOISE (3.2) NOISE (2.3.2) Alternative A, Phases 1 and 2 Project would Minimize noise impacts to None. Same as DEIS Same as DEIS Same as DEIS introduce vehicle adjacent properties noise into existing through appropriate site developed and future design of future development sites. development or redevelopment. (0) Short term construc- Implement mitigation None. Same as DEIS Same as DEIS Sarne as DEIS tion noise impacts on measures required b July 1997 1-8 rclS Significant Impacts, Mitigation Measures, and Unavoidable Adverse Impacts Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0) Optional Adverse Impacts (0)Optional Adverse Impacts adjacent developed Renton City Code. (R) properties. GEOLOGY AND GEOLOGY AND SOILS SOILS (3.3) (2.3.3) Alternative A, Phases 1 and 2 Water and wind Comply with City of Mitigation measures will Same as DEIS Same as DEIS Same as DEIS erosion of soils. Renton Standard Speci- not completely stop fication for Municipal water and wind erosion. Construction and King County Surface Water Design Manual (as adopted by the City of Renton, Title IV, City of Renton Building Regu- lations, Chapter 22). (R) Comply with the City of Renton Land Clearing and Tree Cutting Ordinance and Mining, Excavation, and Grading Ordinance for vegetation clearing and earthwork. (R) Provide mitigation plan for clearing and grading. (R) Cover topsoil with plastic sheeting during construction. (R) Replant newly con- structed earthen em- bankments, roadway shoulders, drainage channels with erosion control seed mixtures as July 1997 rr r r r r r r r r r r r r rr r rr r r r Final Environmental Impact Statement 1-9 Oakesdale Avenue S. V. Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0) Optional Adverse Impacts (0)Optional Adverse Impacts soon as possible. (R) Stabilized construction access points to limit tracking of soils on to the existing roadways. (R) Clean adjacent roadways. (R) Limit stormwater runoff, erosion, and sediment transport from exposed and/or new impervious areas by using detention and sediment control such as silt fences, anchored straw bales, and temporary sedimen- tation ponds. (R) Preserve a buffer zone adjacent to wetland and creek areas,whenever possible. (0) Alternative A will Test excavated materials None. Same as DEIS Same as DEIS Same as DEIS require about 29,200 for use as fill material to and 12,600 cubic reduce quantity of yards of fill for Phase material brought in from 1 and Phase 2, off-site. (R) respectively. Post-construction Use special construction Differential setllernent Same as DEIS Same as DEIS Same as DEIS settlement of soils. sequences and of existing utilities will procedures. (R) occur to a lesser degree. Hydraulic Use light-weight embankment materials. conditions in gravity (0) lines may be altered. July 1997 1-10 FEIS Significant Impacts, Mitigation Measures,and Unavoidable Adverse Impacts Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0)Optional Adverse Impacts (0) Optional Adverse Impacts Structures will be Use structure and pipeline None. Same as DEIS Same as DEIS Same as DEIS located in a seismic construction practices in area. Uniform Building Code appropriate to seismic zone 3. (R) Design of bridges should withstand low to moderate levels of ground shaking and to resist structural failure during extreme seismic events. (R) Reduce the likelihood of liquefaction by using ground densification techniques such as vibro- flotation, installation of stone columns, or dynamic compaction. (R) SURFACE WATER SURFACE WATER QUANTITY/QUALITY QUANTITY/QUALITY (3.4) (2.3.4) Surface Water Quantity Alternative A, Phases 1 and 2 For Phase 1 and Provide compensatory None. For Phases 1 and 2 of Same as DEIS Same as DEIS Phase 2, fill within the flood storage. (R) the refined Alternative FEMA 100-year A, fill within the City of Z floodplain would result Comply with one 's Renton 100-year in the loss of 330 and Flood Hazard Zone Ordinance. R floodplain would result 7,970 cubic yards, ( ) in the loss of 1,380 and respectively, of flood Include location of 100- 8,500 cubic yards, storage. year floodplain on respectively, of flood roadway plans. (R) storage. July 1997 Final Environmental Impact Statement Oakesdale Avenue S.W. Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0) Optional Adverse Impacts (0) Optional Adverse Impacts For Phase 1 and Design and analysis of Some loss of infiltration For Phases 1 and 2 of Analysis and design of Same as DEIS Phase 2, increased surface water runoff to groundwater due to the refined Alternative surface water runoff surface water runoff conveyance system, increased impervious A, increased surface conveyance system, due to addition of 7.16 including control of runoff area. water runoff due to the and peak discharge and 0.40 acres, discharge, per King addition of 7.07 and control, per King County respectively, of County Surface Water 0.40 acres, Surface Water Design impervious surface. Design Manual respectively, of Manual (KcsWDM) (KCSWDM) adopted by impervious surface. adopted by the City of the City of Renton, and Renton and Department per other city, state and of Ecology's federal regulations. (R) Stormwater Manual for Puget Sound. ( R) Phase 1 would require Relocate outlet control None. Refined project avoids Not applicable. Not applicable. relocation of the structure in coordination impact.. Boeing CSTC wet- with affected property land/detention outlet owner, and in accordance control structure. with City of Renton and other local, state and federal, requirements. (R) Interruption of existing Provide substitute con- None. Same as DEIS Same as DEIS Same as DEIS surface water flow veyance systems in patterns and coordination with affected conveyance systems property owners, and in in Phase 1 accordance with City of Renton requirements. (R) Under Phase 1, Participate in the City of None. Refined project avoids Not applicable. Not applicable. increase in Spring- Renton ESGRW Project's impact_. brook Creek upstream proposed Springbrook water surface eleva- Creek channel widening lion as a result of improvements for mitiga- placement of bridge tion of increase in water column/pier in the surface elevations. (R) 100-year flow stream channel. July 1997 1-12 FEIS Significant Impacts, Mitigation Measures, and Unavoidable Adverse Impacts Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0)Optional Adverse Impacts (0)Optional Adverse Impacts Surface Water Quality Alternative A, Phases 1 and 2 Potential for increased Minimize soil erosion and Percentage of nutrients Same as DEIS Same as DEIS Same as DEIS sediment, nutrient sedimentation using best and metals from the site loads, and management practices would enter receiving contaminants per KCSDWM and waters reaching wetlands Renton Storm and and Springbrook Surface Water Drainage Creek during and Ordinance, and through following construction. implementation of the provisions set forth in the City of Renton Standard Specifications for Municipal Construction. (R) Construction would likely Same as DEIS Same as DEIS Same as DEIS require temporary Water Quality Modification from Ecology. (R) Comply with surface Same as DEIS Same as DEIS Same as DEIS water quality protection requirements of Land Clearing and Tree Cutting Ordinance and Mining, Excavation, and Grading Ordinance. (R) Provide water quality Provide water quality Same as DEIS treatment(biofiltration treatment per the 1990 swales,wetpond or KcswDM adopted by the combination welvault and City of Renton, and the biofiltration swale) per Department of July 1997 Final Environmental Impact Statement 1-13 Oakesdale Avenue S.W. Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0)Optional Adverse Impacts (0) Optional Adverse Impacts 1990 KCSWDM adopted Ecology's Stormwater by the City of Renton. (R) Manual for Puget Sound. (R ) Obtain a NPDES Permit Sarne as DEIS Same as DEIS Same as DEIS from Ecology. (R) Comply with applicable Same as DEIS Same as DEIS Same as DEIS state Hydraulic Code Rules and HPA Permit conditions. (R) Maintenance of water Same as DEIS Same as DEIS Same as DEIS quality treatment facilities to ensure that they function as intended. (0) Potential for warm Provide landscaping None. Same as DEIS Same as DEIS Same as DEIS stormwater runoff around open detention reaching Springbrook facilities to reduce Creek warming of stormwater. (0) WETLANDS (3.5) WETLANDS (2.3.5) Alternatives A, Phases 1 and 2 Potential temporary Minimize and mitigate for None. Same as DEIS Same as DEIS Same as DEIS loss of wetland loss of wetland as acreage and required by City of functional values as a Renton. (R) result of filling and shading. Activities affecting wet- lands likely subject to Sections 401 and 404 of the Federal Clean Water Act. (R) Create wetland by re- moving the earth berm July 1997 1-14 FEIS Significant Impacts, Mitigation Measures,and Unavoidable Adverse Impacts Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0) Optional Adverse Impacts (0)Optional Adverse Impacts separating Welland F (City of Renton) and Wetland G (City of Renton) and the Longacres Office Park south marsh. (0) WILDLIFE, WILDLIFE, FISHERIES, AND FISHERIES, AND VEGETATION (3.6) VEGETATION (3.6) Alternative A, Phases 1 and 2 Loss of forest, field, Conformance with Net loss of native Sarne as DEIS Same as DEIS Sarne as DEIS and wetland regulations of the City of vegetation and wildlife vegetation resources Renton Land Clearing habitat. and loss of wildlife and Tree Cutting habitat. Ordinance, and Mining, Excavation, and Grading Ordinance. (R) Re-seed upland areas Same as DEIS Same as DEIS Same as DEIS with perennial grass immediately following construction. (R) Plant native vegetation types in disturbed areas adjacent to the project right-of-way. (0) Landscaping along the roadway edges within the project right-of-way. (0) Coordinate plantings and landscaping with adjacent property owners. (0) July 1997 Final Environmental Impact Statement 1-IS Oakesdale Avenue S.W. Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0) Optional Adverse Impacts (0) Optional Adverse Impacts Creation of barrier to Bridges will allow some Creation of barrier for Same as DEIS Box culvert will allow Same as DEIS wildlife movements. wildlife movement under some wildlife species. sorne wildlife the new road. (0) movement under the Phase 2 roadway. Short-term distur- Replace vegetation, in None. Short-term disturbance Same as DEIS Same as DEIS bance of native kind,where necessary. of native vegetation vegetation during (R) during retained fill bridge construction in construction in the the CSTC wetland. CSTC welland. Short-term distur- Avoid land clearing Temporary disruption Same as DEIS Same as DEIS Same as DEIS bance of wildlife, during nesting periods to wildlife, wildlife wildlife habitat, and (early spring), if possible. habitat, and fisheries fisheries resources (0) resources. during construction. Permanent and Relocate, avoiding None. Same as DEIS Same as DEIS Sarne as DEIS temporary relocation nesting periods, if of wildlife enhance- possible. (R) inenl features. Planting plans for wet- lands,wetland buffers, and disturbed areas could include habitat enhancement features. (0) Potential sedimenta- Conformance with None. Same as DEIS Same as DEIS Same as DEIS tion of Springbrook measures in WDFW Creek during HPA permit. (R) construction. Prepare and implement erosion/sedimentation control plan. (R) July 1997 1-16 FEIS Significant 1n►pacts, Mitigation Measures, and Unavoidable Adverse Impacts Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0) Optional Adverse Impacts (0) Optional Adverse Impacts LAND AND LAND AND ' SHORELINE USE SHORELINE USE (3.7) (2.3.7) Alternative A, Phases 1 and 2 Potential short term See Sections 3.1, 3.2 and None. Same as DEIS Same as DEIS Same as DEIS construction impact 3.3 for mitigation for on adjacent land use. construction related air, noise and dust impacts, respectively. (R) Coordinate construction activities to minimize impacts on adjacent businesses. (R) Land acquisition and Compensate property None. Same as DEIS Sarne as DEIS Same as DEIS easements required owners for land for roadway right-of- acquisition. (R) way, drainage facilities and wetland Investigate adjustments to mitigation. roadway alignment to minimize impacts. (0) Project will require Obtain a substantial None. Same as DEIS Same as DEIS Same as DEIS construction in urban development permit for and conservancy shoreline construction. shoreline (R) environments. SOCIAL ELEMENTS SOCIAL ELEMENTS (3.8) (2.3.8) Alternative A, Phases 1 and 2 Phase 1 would require Relocate drainage None Refined project avoids Not applicable Not applicable. relocation of the structure in compliance impact. Boeing CSTC wetland with all applicable July 1997 Final Environmental Impact Statement 1-17 Oakesdale Avenue S.W. Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0)Optional Adverse Impacts (0) Optional Adverse Impacts outlet control standards and regulations structure. of local, state and federal agencies. ( R ) Coordinate relocation with affected property owner. (R) Phase 1 will require Relocation will be None identified. relocation of a section coordinated with Boeing of Boeing CSTC and will comply with all irrigation line and the applicable standards vault housing aerating and regulations. ( R) pumps. Phase 1 will require Relocation will be None identified. relocation of water coordinated with lines, hydrants and Boeing,where valves. necessary, and the City of Renton Water Utility, and will comply with all applicable standards and regulations. (R ) Potential settlement and Design and construction None identified. other impacts to King of Phase 2 fill and County Metro 72-inch retaining structures will trunk sewer resulting be coordinated with frorn Phase 2 King County Metro. ( R ) construction. Phase 1 would require Puget Power would None identified. Refined project avoids Not applicable. Not applicable. relocation of 115kV relocate power lines, impact. power lines, where necessary, and in conformance with their requirements to assure disruptions to service would be minimized. (R) July 1997 1-18 AS Significant Impacts, Mitigation Measures, and Unavoidable Adverse Impacts Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0) Optional Adverse Impacts (0) Optional Adverse Impacts Phase 2 construction King County Metro would None. Same as DEIS Sarne as DEIS Same as DEIS would place bridge be included in the design structure close to, and process for the structure potentially impact, an footings in the vicinity of existing 72-inch Metro this 72-inch sewer. (R) trunk sewer. Special coordination and precautionary measures would be taken if pile driving is allowed near the 72-inch sewer. (R) TRANSPORTATION TRANSPORTATION (3.9) (2.3.9) Alternative A, Phases 1 and 2 Phase 1 would place Project is included in city- None. Same as DEIS Same as DEIS Same as DEIS a public road and wide transportation plan traffic in an area (SW to reduce delays and 16th to SW 27th improve access and Street) currently safety for forecast year without public access, 2010 conditions and and would beyond. (R) substantially increase traffic on Oakesdale Avenue SW south of SW 31 st Street. Phase 1 would result Comply with all applicable None. Same as DEIS Same as DEIS Same as DEIS in short-term delays to regulations, provisions, local access and and construction through traffic techniques for (vehicles and maintaining motorized pedestrians) on SW and non-motorized traffic 16th Street during flow and safety within and construction. through the construction area. (R) July 1997 Final Environmental Impact Statement 1-19 Oakesdale Avenue S. Y. Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0) Optional Adverse Impacts (0) Optional Adverse Impacts PARKS AND PARKS AND RECREATION (3.10) RECREATION (2.3.10) Alternative A, Phases 1 and 2 Temporary closure of None proposed. Short-term impacts Same as DEIS Same as DEIS Same as DEIS the CSTC segment of during construction. the Springbrook Creek Trail and CSTC wetland trail system during Phase 1 road- way and bridge construction. Phase 1 would Relocate the affected None. Same as DEIS Same as DEIS Same as DEIS permanently impact a segment. Relocation segment of the closer to Springbrook Springbrook Creek Creek will be investigated. Trail. Coordinate relocation with the Boeing Company, City of Renton Parks Dept., and the City's ESGRW Project. (R) Phase 1 would Replace and relocate None known at this Same as DEIS Same as DEIS Same as DEIS permanently remove affected segments, if time. portions, and render feasible. Coordinate with unusable other The Boeing Company. portions of the CSTC (R) wetland internal trail system. With Phase 1, None proposed or Users will experience Same as DEIS Same as DEIS Same as DEIS sections of Spring- practical. an increase in noise brook Creek trail and level. CSTC wetland trail system adjacent to July 1997 1-20 FEIS Significant Impacts, Mitigation Measures, and Unavoidable Adverse Impacts Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0) Optional Adverse Impacts (0) Optional Adverse Impacts new roadway would experience increased noise levels. VISUAL VISUAL RESOURCES RESOURCES (3.11) (2.3.11) Alternative A, Phases 1 and 2 Project construction Conformance with None. Same as DEIS Same as DEIS Same as DEIS would create short- regulations of the City of term impacts from Renton Land Clearing clearing of mature and Tree Cutting trees and other Ordinance, and Mining, vegetation. Excavation, and Grading Ordinance. (R) Re-seed upland areas with perennial grass immediately following construction. (R) Phase 1 and 2 would Landscaping along the Corridor visual Phases 1 and 2 Same as DEIS Same as DEIS place elevated road- Phase 1 roadway would character would be roadways would block way (on structure) buffer views of traffic from altered by replacement some views across over wetlands, surrounding hillsides and of vegetation by wetlands. Vehicular blocking some views nearby office and roadway and placing traffic, signing and across these commercial buildings. (R) elevated bridge lighting would be visible wetlands. Vehicular structures over from areas with views of traffic, signing and wetlands and the project site. lighting would be Springbrook Creek. visible from areas with views of the project site. Traffic would The use of shielded None. Same as DEIS Same as DEIS Same as DEIS introduce light and lighting fixtures would glare into an area reduce light and glare where it is negligible impacts. (R) July 1997 r ri r r r r r r r r rr r r r r r r r r Final Environmental Impact Statement I-21 0akesdale Avenue SAV. Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0) Optional Adverse Impacts (0) Optional Adverse Impacts or non-existent. Use trees and shrubs to screen light and glare. Coordinate landscaping with adjacent property owners. (0) Potential for Use shielded lighting None identified illumination impacts fixtures, particularly on some wildlife in wetland areas. species HISTORIC AND HISTORIC AND CULTURAL CULTURAL RESOURCES (3.12) RESOURCES (2.3.12) Alternative A, Phases 1 and 2 Potential of detecting If archaeological sites are None. Same as DEIS Same as DEIS Same as DEIS cultural artifacts discovered, Chapter during soil excavation. 27.53 RCW requires that the state OAHP be contacted. (R) Stop work if sites are found and evaluate the need for further treatment. (0) HAZARDOUS HAZARDOUS MATERIALS (3.13) MATERIALS (2.3.13) Alternative A, Phases 1 and 2 Potential for spills and Minimize the potential Potential accidents Same as DEIS Same as DEIS Same as DEIS leaks of hazardous release of hazardous resulting in releases to materials during materials during soil, surface water, or July 1997 1-22 F1 IS Significant Impacts, Mitigation Measures,and Unavoidable Adverse Impacts Alternative A in DEIS Refined Alternative A in FEIS Mitigation Measures Significant Mitigation Measures Significant Significant Impacts (R) Required Unavoidable Significant Impacts (R) Required Unavoidable (0) Optional Adverse Impacts (0) Optional Adverse Impacts construction and construction and ground water. operation. operation as required by City of Renton regulations. (R) July 1997 Final Environmental Impact Statement 2-1 Additional Information 2. Additional Information 2.1 Introduction ' This section presents additional information on: 1) the selection of Alternative A as the Preferred Alternative; 2) refinements to the Preferred Alternative to further reduce its impacts; and, 3) changes in existing conditions, impacts and mitigation measures resulting from these refinements. ' This section also includes additional information on the affected environment, impacts and mitigation measures in response to comments received on the Draft Environmental Impact Statement(DEIS). ' For several of the elements of the environment evaluated in the DEIS, no additional information was required. ' 2.2 Alternatives 2.2.1 Selection of the Preferred Alternative ' Of the two build alternatives (Alternatives A and C) and the No-Build Alternative, the City of Renton has selected Alternative A as the Preferred Alternative. ' Information in the DEIS, addtional study, and comments received were used to determine that this alternative provided the most direct route for the new roadway with the least impact on the environment; thus, it is the best of the three alternatives in meeting the project's objectives. ' 2.2.2 Alternative A - The Preferred Alternative Recommendations of a Value Engineering Study investigating options to further minimize impacts of the ' project(and reduce the cost of the project), discussions with the U.S. Army Corps of Engineers and other agencies preliminary to the Section 404 Permit application process, and comments required on the DEIS have resulted in refinements to the horizontal alignment of Alternative A. This new alignment differs from the Alternative A alignment described in the DEIS in the following respects: 1. Beginning at the existing Oakesdale Avenue S.W. and S.W. 16th Street intersection, the new alignment curves further to the southwest through Benaroya Company property than the DEIS alignment, crosses Springbrook Creek about 300 feet south of S.W. 16th Street (compared to 400 feet in the DEIS alignment), and enters the Boeing Customer Service Training Center (CSTC) ' property. At this point the new alignment is approximately 90 feet west of the DEN alignment. The new alignment then gradually curves to the south through the CSTC property and enters the Boeing Lon-acres Office Park property continuing on a gradual curvature east of the DEIS alignment (up to ' a maximum of 40 feet to the east at S.W. 19th Street) until it matches with the DEIS alignment approximately 800 feet south of S.W. 19th Street. (Refer to Figure 2.2.2.-1) A 400-foot long bridge crossing both Springbrook Creek and the CSTC constructed "delta" wetland was proposed in the DEIS. The new alignment, being shifted further to the west than the DEIS, crosses the westernmost edge of the CSTC "delta" wetland. Filling this westernmost wetland area to accommodate the new roadway is proposed, rather than a bridge across it, following discussions with ' the Corps of Engineers, state agencies and The Boeing Company. Shifting the DEIS alignment further to the west also improves the skew angle at the Springbrook Creek crossing. As a result a single-span bridge, approximately 140 feet in length, is proposed at this crossing. City of Renton FEIS Oakesdale Avenue S.W. ' _- ' — - - - r. \,�1'.,,' ,\ 77 , — ~ � •,`�!/ `� i� `I `` � �\�` ._. _. '—'—"'��-`_ --'�...'�i 1. !�� \Ili!"'1I - ,J`� 1 `mil 1'i,i if`'tt END PFKXJECT �` .�.�-'�� -'�,_.` !' 'f� �.� _ ,t , �-" .�(' j' ' .� 1. �-^• t , - .��. ii�rl t"r---• i `�I r'. J� _ ---�1 l �1 t.111i,. ,\ 1' ,_ f,'� I '�i I II 1I. I.v 1�t 1 /I i Lys '.1•,i' BEGN PROJECT 1 It \+ I �Y'Z71iTST—STJCT6+IrAS: E-1 1 ,,r L���� rrfl'llrr�� FEIS REFINED ALIGNMENT }I' �1' / ' :� _ ��_'_ '` -�'� _ f '4 I`r I( � w. 1 ' n. or�0os• RIGHT-OF-WAY A(j/5'i I '�t\ r33 e:. 1�. — - ---�-: su xsuR 4000" �� . g rl �= ==wi �003000S ' �. !�,�.._n ! - - ;-.. _ _, - '� �'_. DEiS AUGNMENT� A/ lr,1I ,:.t—:� t. 471 Sp i - i r L -` — ♦- 1 RIGHT'=OF SWAY y i 111 `I;+ •.I T - 21SaY • ' T. lb.T2 at/ '(1 1 .J i j '1 �- a .-5. ♦i( ti fib `s ,, r: I ,i - ��\ 4.,u!i n `� - :�`\ •;,1 , 1-. I '�j., �! iL!,j Th.. K .-^- -_,•, �`'r � C.c:. ',�� I�. �, - k \?;TES.,REFINED-ALIGNMENT "A" � j - - �... OAKESDALE:.AV-E� _ - 1 _ - T - _ GH - 1 01.31'39'E-.. t'.. `�+! � R . . n. � N'Ot•13'lt--C<"� .1 .i in '„^�.� .- .. � ���i�-N,00'1S�i��/- .- _ _ _ �_ _ _W�Op ..� ` .�� _ . _ �:4' ,. R_ ��- .:_r "s—.� �MTOS -tom• �, �� /- i /: ._ ...a�,�� !=----.���•�II �%"Y'����' ^N.'. r ��a4°�-Ar-"i1'w �`w'�u't�"'�r'- ,�%' R - DC i]'u-6,000' l/. 11�;J - _,� i r,' , �! ?uP'��\`"c'•+ -`i�..FS ! .�(;�,T''• ^ 1dI �� I T - 221 \ 32' NI3, - - '^---r"--, <�r--� `.\ \ / �• ��. - I o _�.J. ���_'�V 1 I I 1 DEIS ALIGNMENT "A" 1 �- sr�I ! \\�`\_�— — _. I�� , �f r -'`_�"�"� Iw RIGHT-OF-WAY N a.' 4a 3.L -_�=;, �, ,•' vl �r + :N _ fir_ } b. LEGEND ' DEIS ALIGNMENT 'A" - - - - -- RIGHT-OF-WAY ' FEIS REFINED ALIGNMENT "A" RIGHT-OF-WAY KIATO& 2003 Western A ven u e FIGURE 2.2.2-9 REFINED ALTERNATIVE A ALIGNMENT ' 555Market Place One ARREN`seattle, WA 98121 INCORPORATED (206)448-4200 Final Environmental Impact Statement 2-3 Additional Information 2. The Alternative A alignment in the DEIS is maintained for a distance of about 1,250 feet, from 800 feet south of S.W. 19th Street to approximately 500 feet north of S.W. 27th Street, where the new ' alignment diverges from the DEIS alignment as it continues south to S.W. 27th Street. At S.W. 27th Street, the new alignment is about 25 feet west of the DEIS alignment. (Refer to Figure 2.2.2-1.) With this shift in alignment, more of the proposed project will be located on the Boeing Longacres ' Office Park property, and less on City of Renton property, than was proposed with the DEIS alignment. 3. South of S.W. 27th Street, the refined Alternative A alignment continues south parallel to, and ' approximately 30 feet west of the DEIS alignment for about 500 feet. At this point the new alignment gradually curves to the southeast to join existing Oakesdale Avenue S.W. at S.W. 31st Street. (Refer to Figure 2.2.2-1.) tA 600-foot long bridge crossing over a City of Renton wetland in this segment of the project was proposed in the DEIS. Shifting the DEIS alignment to the west allows the new roadway to be incorporated with the existing earth embankment that separates the City of Renton wetland on the east from the wetland areas on the west. Filling the wetland to accommodate the remainder of the new roadway is proposed, rather than a bridge structure over the wetland, following discussions with the Corps of Engineers and state agencies. Replacing the existing 48-inch culvert crossing under the existing earth embankment with a box culvert under the new roadway is proposed in order to improve hydrology between the existing wetlands on the east and west, and to improve access between these wetlands for wildlife. Typical roadway cross-sections for the refined Alternative A (Preferred Alternative) are shown in Figure 2.2.2-2. ' 2.2.3 Construction Sequencing Due to funding constraints, the proposed project's construction phasing described in the DEIS has been modified as follows: 1. Phase I would construct the ultimate five-lane roadway with bike lanes, curb and gutter and sidewalks on each side, and associated improvements from S.W. 16th Street to S.W. 19th Street; and a three-lane roadway with curb, gutter, sidewalk and associated improvements on the west side from S.W. 19th Street to S.W. 27th Street. Surface water runoff conveyance/detention/treatment systems for the ultimate five-lane roadway between S.W. 16th Street and S.W. 27th Street would be installed in Phase 1. Also wetland mitigation for the ultimate five-lane roadway between S.W. 16th Street and S.W. 27th Street would be addressed in Phase 1. . 2. When funding becomes available, Phase 2 will complete the ultimate five-lane roadway and associated improvements between S.W. 19th Street and S.W. 27th Street, and complete the extension of Oakesdale roadway from S.W. 27th Street to S.W. 31 st Street. ' City of Renton 2-4 FEIS Oakesdale Avenue S.W. ' R/W R/W R/W R/W 45' 45' 45' 45' ULTIMATEDIMENSIONS 4 8' ' 11' I 11' 12' 11'T 11' S'�'''T'�8'—%-4' L SANE CENTER TURN ' S E ' LANE LANE ORMEDIAN LAA NE I- I—7—� I INTERIM I 1 SHOULDER ' 8' BIKE 71 it' it' 17' 1K 8' a' 8' 12' 12' 12' a'� BIKE BIKE DIMENSIONS LANE LANE PHASE 2 CONSTRUCTION i X D EXISTIN GRADE G C EXISTING /GRACE -� - -- ---- --- --- — EXISTING GRADE 7 EXIS TING ' GRADE TYPICAL ROADWAY SECTION(PHASE 2) TYPICAL SECTION SOUTH OF S.W.27TH ST. S.W.27TH ST.TO S.W.19TH ST. R/W R/W 45' 45' 1.5' 6.5' S' 17' 17'—«--12' 1' 1' 5' 6.5'-- G—1.5' BIKE MEDIAN BIKE LANE LANE I 8' S' 11' it' 12 17' tt' S' 8' BIKE CENTER TURN BIKE LANE LANE OR MEDIAN LANE � A EXISTING X'SDE I — —— ———— _—— ' — — —— ——— OR — 75'-2" OR __ n SPACES AT 6'-;0" d P?� TYPICAL SECTION TYPICAL BRIDGE SECTION 5Marj�prQB 200311'eslernAvenue One S.W.19TH ST.TO S.W.16TH ST. AT SPRINGBROOK CREEK WARREN 55attie, rA 981 1 ' Sea tt/e. AA 00 INCORPORATED (208)448-4200 FIGURE 2.2.2-2 REFINED ALTERNATIVE A —TYPICAL ROADWAY CROSS SECTIONS ' Final Environmental Impact Statement 2-5 Additional Information ' 2.3 Affected Environment, Impacts, and Mitigation The revised elements of construction in Phases 1 and 2 are not significantly different from that described in the DEIS. Therefore, changes to existing conditions, impacts, and mitigation presented in this FEIS will be based on the existing conditions, impacts and mitigation measures associated with each phase of the project defined in the DEIS. 2.3.1 Air Quality No comments were received and no additional information is needed for this EIS. 2.3.2 Noise ' No comments were received and no additional information is needed for this EIS. 2.3.3 Geology and Soils 2.3.3.1 Affected Environment No comments were received and no additional information is needed for this EIS. 2.3.3.2 Impacts The height of embankments in Phase 2 of the refined Alternative A south of S.W. 27th Street will range from one to ten feet rather than one to twenty feet as noted for Alternative A in the DEIS. TABLE 2.3.3-1 EXCAVATION AND FILL QUANTITIES(CUBIC YARDS Phase Excavation Fill ' Refined Alternative A (FEIS) 1 29,200 2 12,600 Total 41,800 Alternative A (DEIS) 1 7,800 19,140 2 0 5,700 Total 7,800 24,840 No comments were received and no other additional information is needed for the EIS as a result of the refinements to Alternative A in this FEIS. ' 2.3.3.3 Mitigation No comments were received and no additional mitigation measures are needed as a result of the refinements to Alternative A in this FEIS. City of Renton 2-6 ' FEIS Oakesdale Avenue S.W. 2.3.3.4 Impact Summary , Significant Unavoidable Significant Impacts Mitigation Measures Adverse Impacts The refined Alternative A will No additional measures needed. None. require about 29,200 and 12,600 cubic yards of fill for Phase 1 ' and Phase 2, respectively. 2.3.4 Surface Water Quantity/Quality 2.3.4.1 Introduction No comments were received and no additional information is needed for the EIS. ' 2.3.4.2 Affected Environment Studies and Coordination In the DEIS, adopted FEMA 100-year flood elevations were used to compute compensatory storage required for the proposed project. It was also noted in the DEIS that recent modeling of the Black River ' Basin watershed by the City of Renton (which includes Springbrook Creek) shows the lower reaches of Springbrook Creek near the proposed project too be one to three feet lower than FEMA elevations. Further review of the mofeled results by the City of Renton since issuance of the DEIS has determined , that the City's modeled 100-year floodplain elevations are appropriate for use in computing the volume of compensatory storage required to mitigate for filling within the 100-year floodplain of Springbrook Creek. Where the FEMA defined 100-year floodplain is lower than the City's model results, the FEMA elevations are still to be used. Since FEMA elevations will be lower only in a section of Springbrook Creek between S.W. 41st Street and S.W. 43rd Street, the City's model elevations have been used in determining compensatory storage for the refined Alternative A in this FEIS. ' Existing Drainage Facilities Other existing storm sewer facilities in the Oakesdale project area not identified in the DEIS include: ' • Two existing storm drain inlets with 6-inch pipe outlets to the west located on the Boeing Longacres Office Park property; one located approximately 100 feet, and the second approximately 200 feet, , north of S.W. 27th Street; • A 6-inch culvert under an existing east-west dirt road located on Longacres Off-ice Park Property ' about 1,000 feet north of S.W. 27th Street; and • Eleven inlets with 6-inch pipe outlets drain an existing paved access road within the Boeing CSTC property north of S.W. 19th Street. Eight inlets outlet to the CSTC "riverine" wetland on the west side of the existing road, and three inlets outlet to the CSTC "delta" on the east side of the roadway. 2.3.4.3 Impacts Surface Water Quantity Table 2.3.4-1 compares the increase in impervious surface resulting from the refined Alternative A in , this FEIS and Alternative A in the DEIS. ' Final Environmental Impact Statement 2-7 Additional Information ' TABLE 2.3.4-1 INCREASE IN IMPERVIOUS SURFACE(ACRES) Refined Alternative A (FEIS) Phase 1 7.07 Phase 2 0.40 Alternative A (DEIS) Phase 1 7.16 Phase 2 0.40 Surface Water Runoff Svstems For the refined Alternative A in this FEIS, storm sewer systems will collect surface water runoff from all impervious areas including sidewalks, roadways, and fill slopes at the back of the sidewalk. The grass strip behind the curb noted for Alternative A in the DEIS has been deleted from the refined Alternative A proposal (see typical cross-sections in Figure 2-3). ' Surface water runoff quantities have been evaluated, and a storm drainage system developed, for the refined Alternative A according to: 1) requirements outlined in the 1990 King County Surface Water Design Manual adopted by the City of Renton (the same as was done for Alternative A in the EIS); and, 2) requirements of the Washington Department of Ecology's Stormwater Manual for Puget Sound. For the refined Alternative A, surface water runoff would be collected in catch basins at the roadway curbs and conveyed in enclosed pipes to detention and/or water quality treatment facilities (no change from the ' DEIS). All treated stormwater would be discharged directly to Springbrook Creek or to wetlands tributary to Springbrook Creek (no change from the DEIS). However, the number of drainage systems for the refined Alternative A has been reduced from the five (A, B, C, DE and F) proposed in the DEIS to four(A, B. C and F). The detention and water quality treatment facilities proposed for Systems B, C and F have been changed from that proposed in the DEIS. The four drainage system concepts proposed for the refined Alternative A are described below and shown on Figure 2.3.4-1. ' For the Phase 2 segment of the refined Alternative A in this FEIS (S.W. 27th Street to S.W. 31st Street) drainage System A would remain unchanged from the concept described in the DEIS. Surface water from the southern half of the Phase 2 segment would be conveyed by curb and gutter to catch basins and a closed conveyance system. A biofiltration swale would provide water quality treatment before outfalling into an adjacent existing wetland. System B would include the north half of the Phase 2 segment (to S.W. 27th Street) and a segment of the Phase 1 project from S.W. 27th Street to ' approximately 500 feet north of S.W. 27th Street. Surface water runoff would be conveyed by curb and gutter to catch basins and a closed conveyance system. Water quality treatment would be provided by a combination wetpond/biofiltration Swale facility located in an area between the proposed east side ' Oakesdale sidewalk and an existing wetland north of S.W. 27th Street. After treatment, System B would outfall to an existing wetland south of S.W. 27th Street which would serve as a detention facility to provide peak discharge control. (In the DEIS, peak discharge control and water quality treatment would ' have been provided by a combination wetpond/detention facility located in the existing adjacent wetland north of S.W. 27th Street and then outfall to an existing wetland south of S.W. 27th Street. This proposed change in System B water quality treatment and detention: 1) would reduce wetland impacts; ' 2) is possible due to shifting the refined Alternative A alignment to the west; and 3) provide runoff treatment and control equal to or exceeding that proposed for Alternative A in the DEIS. System C would collect surface water runoff from Phase I of the proposed project between System B and the high point of the roadway at the south end of the bridge across Springbrook Creek, an overall length of approximately 1,800 feet. Surface water runoff would be conveyed by curb and gutter to catch 4 „3 13 eie V�ult with �+-Nartle rdg "' SprinjbnktiCreek System C. W Z _r',d`Str,;q - C.D. a -- � r ✓x.'- �;.. r �''��• constructed wetland t"(wetpond),with Y outfall to,wetland th-S,t n N System B. 3 wetpond with -_ :outfall,towetland , `� System A.. �# Ibiofiltration swale, a with outfall to wetland $ N a 20Q 400 800:Feet a t rn' R a ter': 61i � ae Aerial Pltotopt9 Y •-�.. -. ' City of Renton 2-9 FEIS Oakesdale Avenue S.W. basins and a closed conveyance system running parallel under the proposed roadway. This system would outfall into a constructed combination wetpond/biofiltration swale facility, located at the south end of System C and adjacent to the east side of the proposed roadway, which will provide water quality treatment. After treatment, System C surface water runoff would flow into an existing adjacent wetland which would provide peak discharge control. System C in this FEIS: 1) combines System C and DE in the DEIS into a single system; 2) eliminates the wetvault, biofiltration swale and outfall directly into Springbrook Creek at S.W. 19th Street that was proposed for System DE in the DEIS; 3) eliminates the System C combination wetpond/detention facility proposed in the DEIS; and, 4) provides treatment and control equal to or exceeding that proposed for Alternative A in the DEIS. The revised System C ' drainage system avoids wetland impacts, minimizes direct discharge into Springbrook Creek, and eliminates the need for an easement on private property to accommodate a wetvault, biofiltration swale and outfall. System F in this FEIS would collect surface water runoff from the Phase 1 project segment between the south end of the new bridge over Springbrook Creek and S.W. 16th Street (similar to System F in the DEIS). Surface water runoff would be conveyed by curb and gutter to catch basins and a closed conveyance system running parallel under the proposed roadway(similar to System F in the DEIS). At a point along the conveyance system near S.W. 16th Street the runoff would drain into a wetvault for water quality treatment (rather than a biofiltration swale as proposed for System F in the DEIS). The wetvault would discharge into an existing storm sewer system in S.W. 16th Street and eventually into Springbrook Creek. Lack of space for a biofiltration Swale due to shifting the DEIS Alternative A alignment further to the west has resulted in the water quality treatment facility proposed for System F in this FEIS. The level of runoff treatment and control will remain unchanged from that proposed for Alternative A in the DEIS. Floodplain Storage Floodplain storage impacts in the DEIS was based on FEMA 100-year peak flows and water surface elevations along Springbrook Creek north of S.W. 27th Street. Since issuance of the DEIS, the City of Renton has determined that the City's modeled 100-year flood event elevations can be used to compute compansatory requirements for the proposed project. Preliminary estimates of fill quantities for Phase I and 2 of the refined Alternative A based on Renton modeled 100-year floodplain elevations are presented in Table 2.3.4-3. This table also includes the estimated fill quantities for Alternative A in the DEIS (based on the FEMA 100-year floodplain elevations). 1 City of Renton 2-10 ' FEIS Oakesdale Avenue S.W. i TABLE 2.3.4-2 FLOODPLAIN STORAGE IMPACTS (Cubic Yards of Displacement) Refined Alternative A Alternative A (FEIS) (DEIS) ' Phase 1 Phase 2 Phase 1 Phase 2 100-Year Renton modeled 1,380 8,500 — — ' floodplain impact 100-Year FEMA floodplain impact — — 330 3,770 Bridge Piers in the Floodwav Phase 1 of the refined Alternative A in this FEIS includes a 140-foot long single-span bridge across Springbrook Creek. This bridge would be designed to provide a minimum clearance of two feet above the City of Renton 100-year floodplain elevation at the crossing of Springbrook Creek. (A minimum ' clearance of three feet was provided in the DEIS.) Since issuance of the DEIS, the City of Renton has reviewed the minimum clearance requirement and has lowered it to two feet for this Oakesdale Avenue S.W. project in recognition of the benefits that a single-span bridge with no piers in the low flow channel would have to channel capacity during conveyance condition flows. The proposed single-span bridge would be located so that the bridge abutments would not encroach into , the future land use 100-year conveyance event flow and, therefore, would not increase the water surface elevation upstream under this 100-year conveyance event. (The bridge proposed in the DEIS would have increased the water surface elevation by 0.1 feet at the upstream edge of the bridge under this 100-year conveyance event condition.) Also, the Phase 1 refined Alternative A bridge across Springbrook Creek would not require compensatory storage for the future land use 100-year storage event. The 100-year storm event flow velocities under this single-span bridge are anticipated to be sufficient to cause channel , scour, or erosion, at the abutments. (Channel scour was also identified as a potential impact in the DEIS). Surface protection (e.g. rip-rap) under the bridge at the abutments would prevent channel erosion. , Phase 2 of the refined Alternative A does not include a bridge structure. Therefore, the bridge pier/abutment potential impact noted in the DEIS would not occur in the refined Alternative A in this FEIS. ' Groundwater As with Alternative A in the DEIS, Phases 1 and 2 of the refined Alternative A in this FEIS could impact , subsurface hydrology and groundwater. Phases 1 and 2 of the modified Alternative A are anticipated to add 7.07 acres and 0.4 acres, respectively, of impervious surface. The conversion of areas of absorptive surface soils to impervious surfaces could result in some loss of infiltration to groundwater. ' Existing Drainage Facilities The existing 12-inch pipe which conveys surface water runoff from the former stable area on Longacres ' Office Park property to the east into an existing wetland area at the south end of the former practice track Final Environmental Impact Statement 2-11 Additional Information area. The Phase 1 roadway embankment proposed for the refined Alternative A in this FEIS would cover the inlet of this pipe (as would Alternative A in the DEIS). To prevent impacts to the adjacent property, the refined Alternative A proposes to install a new pipe from the existing catch basin on the west side of the new roadway to a new catch basin and outfall pipe on the east side of the new roadway, which will then discharge into the existing wetland. (In the DEIS, the existing catch basin on the west side of the ' new roadway would have been replaced and a new pipe installed along the west side to convey flow to the north to connect to an existing pipe system which discharges to the east into the middle of the former practice track.) The inlet of the existing 12-inch pipe system discharging into the middle of the former practice track will be covered by new roadway embankment proposed for the refined Alternative A. To prevent impacts to adjacent property, a new inlet will be installed on the west side of the new roadway to collect off-site runoff and connected to the existing pipe. A second catch basin will be installed in line ' with the existing pipe as part of the proposed project's storm drainage system. This catch basin would be designed to allow the existing 12-inch pipe to pass through it and continue to discharge into the former practice track as it does currently. (In the DEIS, replacement of the existing pipe under the new roadway was proposed.) A third existing pipe at the north end of the former practice track would also be impacted ' by Phase 1 of the refined Alternative A (similar to Alternative A in the DEIS). The need for replacement of this pipe will be coordinated with The Boeing Company. ' The three existing inlets with outlet pipes located on Longacres Office Park property north of S.W. 27th Street will be covered with new roadway embankment proposed in the refined Alternative A. These inlet/pipe systems will be relocated or removed in coordination with The Boeing Company. The existing access road on the CSTC property north of S.W. 19th Street will be removed by Phase 1 of the refined Alternative A (similar to Alternative A in the DEIS). Therefore, the numerous inlet/pipe ' systems draining runoff from it will no longer be needed. Any offsite flows from areas on the CSTC property adjacent to the new roadway can be directed to the CSTC delta wetland on the east side of the new roadway without any further independent storm drains under the new roadway. Surface Water Quality For Phases 1 and 2 of the refined Alternative A in this FEIS, surface water runoff from the new impervious surfaces would be subject to water quality treatment either by biofiltration swales, a constructed wetland surface water mitigation facility, or wetvault. See previous additional information under Surface Water Quality. ' Impacts During Construction Bridge construction at the Springbrook Creek crossing and within the existing adjacent Boeing CSTC ' wetland (proposed in Phase 1 of the refined Alternative A in this FEIS) will require Hydraulic Project Approval (HPA) from the Washington Department of Fish and Wildlife (WDFW). Potential impacts to the creek and wetland include sedimentation, turbidity, and erosion associated with construction adjacent ' to, and within, the creek and wetland (similar to Alternative A in the DEIS). Any impacts to Springbrook Creek will be addressed by HPA permit conditions. Construction of the Phase 2 fill and roadway (south of S.W. 27th Street) proposed in the refined Alternative A will also have potential impact ' on the adjacent existing wetland areas, including sedimentation, turbidity, and erosion (similar to Alternative A in the DEIS). Impacts of Operation Phase 1 of the refined Alternative A in this FEIS will cross Springbrook Creek and pass adjacent to wetlands along a portion of its length. The Phase 1 roadway will be constructed on retained fill where it City of Renton 2-12 ' FEIS Oakesdale Avenue S.W. passes through the Boeing CSTC wetland and on earth embankment adjacent to other wetland areas. The ' eastern half of the Phase 2 roadway will also be constructed on retained fill where it crosses over the City of Renton wetland. The western half of this roadway will be constructed on the existing earth embankment adjacent to existing wetland areas. Surface water runoff from the existing and new , roadway embankment, which normally slope between 25 and 33 percent, could introduce sediment to Springbrook Creek and adjacent wetland areas. Generally, the distances to these receiving waters would be short, thereby potentially increasing the amount of sediment entering these receiving waters because , of less chance of filtering before discharge. Relatively small sedimentation impacts at each location could result in cumulative impacts to Springbrook Creek (similar sedimentation impacts were identified for Alternative A in the DEIS). Water quality treatment facilities (biofiltration swales, combination wetpond/biofiltration Swale facilities, or wetvault) proposed for Phases 1 and 2 of the refined Alternative A in this FEIS should remove a high percentage of pollutants (such as fuel, oils, grease and metals) that could be generated by traffic using the new roadway. Water quality treatment facilities are not 100% effective in removing all pollutants; therefore, a small percentage of pollutants could remain suspended in the surface water , leaving the refined Alternative A corridor and eventually entering Springbrook Creek and receiving wetlands. Pollutant removal efficiency would be reduced for storms greater than the 2-year, 24-hour event. ' With Phases 1 and 2 of the refined Alternative A, there would be the potential for warmer storm water runoff reaching Springbrook Creek. This would be the result of storm runoff from hot pavement areas and from detention in wetland areas without adequate shading features. , Comments received have been addressed in this FEIS and no other additional information on impacts is needed for this EIS. , Cumulative Impacts No comments were received and no additional information resulting from the refinements to Alternative A is needed for this EIS. 2.3.4.4 Mitigation Surface Water Quantitv Surface water runoff from Phase 1 and 2 of the refined Alternative A in this FEIS would be collected and , conveyed to existing wetland areas or directly to Springbrook Creek. Prior to entering wetland areas or Springbrook Creek, water quality treatment will be provided through biofiltration swales, combination wetpond/biofiltration swale facilities, and wetvault; and, peak runoff control will be provided through ' detention in existing wetland areas. Analysis and design of the conveyance system, and water quality treatment and detention facilities will comply with the requirements of: the 1990 King County surface Water Design Manual adopted by the City of Renton; the Washington Department of Ecology's ' Stormwater Manual for Puget Sound; and, other applicable local, state and federal regulations. For the refined Alternative A in this FEIS, loss of flood storage associated with the placement of fill in the 100-year tloodplain will be mitigated through compensatory excavation on a one-to-one basis per ' City of Renton requirements (similar to Alternative A in the DEIS). 1,380 and 8,500 cubic yards of storage would have to be provided for Phases 1 and 2, respectively, of the refined Alternative A. These quantities are based on flood elevations established by the City of Renton after further review (since issuance of the DEIS) of recent hydrologic modeling. (See previous additional information under Studies and Coordination.) Measures to provide the compensatory storage required for Phase 1 of the Final Environmental Impact Statement 2-13 Additional Information ' refined Alternative A will include excavation associated with construction of wetland replacement to mitigate Phase 1 wetland impacts. Measures to provide the compensatory storage required for Phase 2 of the refined Alternative A will include excavation associated with construction of wetland replacement to mitigate Phase 2 wetland impacts and, if necessary, at other sites within the Springbrook Creek drainage basin. ' For Phase 1 of the refined Alternative A, potential increase in water surface elevation during the 100- year frequency storm event resulting from the proposed bridge over Springbrook Creek has been eliminated through the type of bridge selected (single-span with abutments out of the 100-year ' conveyance flow) and widening of the channel under the bridge as part of the Phase 1 construction. No additional mitigation is required. Groundwater No comments were received and no additional mitigation measures are required to address impacts ' associated with refinements to Alternative A in this FEIS. Existing Drainage Features ' Due to the shift in alignment of the refined Alternative A in this FEIS, impacts on the existing Boeing CSTC outlet control vault structure will be avoided. Therefore, relocation will no longer be required. Other mitigation proposed for Alternative A in the DEIS is applicable to the refined Alternative A in this FEIS. No comments were received and no additional mitigation measures are required for this EIS. Surface Water Qualitv Surface water runoff from Phases 1 and 2 of the refined Alternative A in this FEIS will receive water ' quality treatment through biofiltration swales, wetponds, constructed wetland/surface water treatment facility, and wetvault. These facilities will comply with the requirements of the 1990 King County Surface Water Design Manual adopted by the City of Renton and the Washington Department of ' Ecology's Stormwater Manual for Puget Sound. Other mitigation proposed for Alternative A in the DEIS is applicable to the refined Alternative A in this ' FEIS. Comments received are addressed above and no additional mitigation measures are required to address impacts associated with the refinements to Alternative A. ' During Construction No comments were received and no additional mitigation measures are required to address impacts associated with the refinements to Alternative A. Operation For Phases 1 and 2 of the refined Alternative A in this FEIS, water quality treatment facilities (biofiltration swales, wetponds, constructed wetland/surface water treatment facility and wetvault) should remove a high percentage of fuel, oils, grease and metals potentially generated by traffic using the proposed roadway. Revegetation and landscape treatment should reduce soil erosion and sediment problems associated with the runoff from embankments created by Phases 1 and 2 of the refined Alternative A in this FEIS. Planting trees and vegetation around the wetponds and constructed City of Renton 2-14 ' FEIS Oakesdale Avenue S.W. wetland/surface water treatment facility could reduce the temperature of surface water runoff before it ' enters wetland areas or Springbrook Creek. No comments were received and no additional mitigation measures are required to address impacts ' associated with the refinements to Alternative A. Unavoidable Adverse Impacts , The water quality treatment facilities proposed for Phases 1 and 2 of the refined Alternative A in this FEIS will not be 100% efficient in removing all pollutants from surface water runoff from the project site. A small percentage of pollutants could eventually enter the receiving waters (wetlands and ' Springbrook Creek). Also, pollutant removal efficiency for large storms (e.g. 2-year, 24-hour event) would be reduced as flows increase. This would be an unavoidable impact during project construction and from vehicular traffic operating on the completed roadway. Even with mitigation, there could be some loss of infiltration to the groundwater due to the increase in impervious area in Phase 1 of the refined Alternative A in this FEIS. , 2.3.4.5 Impact Summary Significant Unavoidable ' Significant Impacts Mitigation Measures Adverse Impacts Surface Water Quantity For Phases 1 and 2 of the refined All measures in DEIS are applicable. None ' Alternative A, fill within the City of No additional measures required. Renton 100-year floodplain would result in the loss of 1,380 and 8,500 cubic yards, respectively, of flood storage. For Phases I and 2 of the refined Analysis and design of surface water Some loss of infiltration to ' Alternative A, increased surface runoff conveyance system, and peak groundwater,due to increased water runoff due to the addition of discharge control, per King County impervious area. ' 7.07 and 0.40 acres,respectively, of Surface Water Design Manual impervious surface. (KCSWDM)adopted by the City of Renton and Department of Ecology's Stormwater Manual for ' Puget Sound. Interruption of existing surface Mitigation measure in the DEIS is None water flow patterns and conveyance applicable. No additional measures ' systems in Phase 1 of the refined required. Alternative A. The refined Alternative A in this FEIS avoids relocation of the Boeing CSTC wetland/detention outlet control structure. Therefore, mitigation proposed in DEIS is no longer necessary. The bridge proposed in Phase 1 of the refined Alternative A in this FEIS does not increase the upstream water ' surface in Springbrook Creek. Therefore, mitigation proposed in the DEIS is no longer necessary. a Final Environmental Impact Statement 2-15 Additional Information Significant Unavoidable Significant Impacts Mitigation Measures Adverse Impacts Surface Water Quality Potential for increased sediment, Provide water quality treatment per Percentage of pollutants from the nutrient loads, and contaminants the 1990 KCSWDM adopted by the project site could enter receiving ' reaching wetlands and Springbrook City of Renton, and the Department waters. Creek during and following of Ecology's Stormwater Manual for construction of Phases 1 and 2 of the Puget Sound. refined Alternative A. All other measures in the DEIS are applicable. No additional measures required. ' For Phases 1 and 2 of the refined Mitigation measure proposed in None Alternative A, potential for warm DEIS is applicable. stormwater runoff reaching Springbrook Creek. 2.3.5 Wetlands ' 2.3.5.1 Introduction No comments were received and no additional information is needed for this EIS. 2.3.5.2 Affect Environment An 0.08 acre area located north of the former practice track on the Boeing Longacres Office Park property and east of the refined Alternative A corridor was identified in the DEIS as a wetland. Since issuance of the DEIS, the Corps of Engineers has visited this wetland and determined it is on fill, and, therefore, will not be a regulated wetland under the City's jurisdiction. The City of Renton also visited this wetland area and determined that this area is drainage ditch, and, therefore, will not be regulated wetland under the City's jurisdiction. Any impacts to this non-regulated wetland area as a result of the ' refined Alternative A are not evaluated in this FEIS. No comments were received and no other additional information is needed for this EIS. ' 2.3.5.3 Impacts Proiect Construction Overview Construction of the extension of Oakesdale Avenue S.W. as proposed under the refined Alternative A in this FEIS would involve clearing, grading, filling, and paving (the same as Alternative A in the DEIS). In addition, a bridge would be constructed over Springbrook Creek and the existing wetland adjacent to ' the west side of the creek. As currently proposed this bridge would be a single-span, 140-foot long structure with a width of 82 feet. Construction of this bridge would require placement of fill for the approaches. South of the bridge the new roadway would pass over the west edge of the existing Boeing ' CSTC constructed "delta" wetland on a retained fill. (For Alternative A in the DEIS, a bridge continued over the CSTC delta wetland resulting in a multi-span, 400-foot long structure.) At the south end of the Oakesdale project (S.W. 27th Street to S.W. 31st Street), the roadway in the refined Alternative A would pass through existing City of Renton wetlands E and F (see Figure 2.3.5-1). An existing road embankment running parallel to the new Oakesdale roadway would be incorporated with a retained fill along the western edge of Wetlands E and F to support the new road. The roadway in this segment of the City of Renton 2-16 ' FEIS Oakesdale Avenue S.W. project would have an overall width of 70 feet, including curbs, gutters and sidewalks. Removal of the ' existing culvert under the existing embankment and replacing it with a box culvert is proposed. (Alternative A in the DEIS proposed a 600-foot long, multi-span structure over a major portion of Wetlands E and F and removal of the existing road embankment.) ' In discussions with regulatory agencies, it was recognized that shading of wetlands constitutes in impact comparable with filling. For each type of impact (filling or shading), mitigation would be required in the ' form of replacement by means of constructed wetlands. The replacement ration depends only upon the quality of the wetlands disturbed, and, for a given quality of wetland, is no different for wetlands disturbed by shading than for wetlands disturbed by filling. I Retaining walls are proposed as a part of the roadway design for the refined Alternative A. Two sections of retaining wall are proposed to minimize roadway embankment within the CSTC delta wetland and Wetlands E and F, one other section of retaining wall is proposed to minimize roadway fill adjacent to ' the existing CSTC "riverine" wetland. Stormwater facilities also would be constructed as part of the Oakesdale project. For the refined ' Alternative A, four stormwater systems are proposed. Water quality treatment and detention facilities will be constructed as a part of these systems and will be located to avoid or have minimal impact on wetland areas. Section 2.3.4 provides additional information on the stormwater systems and facilities ' and the project's effects on surface water quantity and quality. The project as proposed for the refined Alternative A in this FEIS would be constructed in two phases. Phase 1 will construct the ultimate five-lane roadway, bridge and associated improvements between S.W. 16th Street and S.W. 19th Streets and construct a three-lane roadway and associated improvements on the west side only between S.W. 19th Street and S.W. 27th Street. The wetland along the west side of Springbrook Creek, the CSTC delta wetland; and, Wetland C and D (see Figure 2.3.5-1) would be indirectly affected, by Phase 1 surface water treatment and created wetland construction of the refined Alternative A. Phase 2 would complete the ultimate five-lane roadway proposed between S.W. 19th Streets and S.W. ' 27th Streets and would extend Oakesdale Avenue S.W. between S.W. 27th Street and S.W. 31st Street. Mitigation for wetland impacts of the Phase 2 construction between S.W. 19th Street and S.W. 27th ' Street would be mitigated under Phase 1. South of S.W. 27th Street, Wetland areas E and F would be directly affected, and Wetland G and the abutting south marsh to the north would be indirectly affected by Phase 2 construction. The existing earth embankment in this section of the project would not be ' removed (as proposed for Alternative A in the DEIS), but would support a portion of the new Phase 2 roadway. As noted earlier in this section, construction of the roadway proposed for the refined Alternative A would ' require some wetland areas to be filled. The bridge across the Springbrook Creek and the wetland adjacent to the west side of the creek will also create shading impacts. Table 2.3.5-1 presents the amount of wetland area that would be filled or shaded by the refined ' Alternative A in this FEIS and Alternative A in the DEIS. Table 2.3.5-1 also presents the classification of the filled or shaded wetlands as defined by the City of Renton Wetlands Management Ordinance. ' Final Environmental Impact Statement 2-17 Additional Information FIGURE 2.3.5-1 DELINEATED WETLANDS ' O 1-405 ------- �S� Gor 74 / �� S.W.1 6th St. No Wetlands Found y 3 Refined Alternative A In Q "Delta' CSTC 1 - � E 0 Site 'Rivarl S.W.I 9tk St. r c' , E . r gi Longacres c a of Office Park --zi! Site Z, c -- 0 Wetland C Phase 1 Area proposed for project mitigation of wetland impact it da.[.ncl S.W.27th St. Wetland E 1 r : 1.�. Boeing Co.Property Line eland F City Owned . ...... W edond V Phase 2 Area proposed for project mitigation of wetland impact V3 r a NOTE:Wetland locations are approximate. LEGEND: ............. Flagged Wetland Edges 0 800 M7 — Wetlands Extend Outward Scale in Feet City of Renton 2-18 ' FEIS Oakesdale Avenue S.W. TABLE 2.3.5-1 CALCULATION OF WETLAND AREA FILLED OR SHADED ' Refined Alternative A Alternative A (DEIS) (FEIS) Wetland Area Renton Classification Area Filled or Shaded t Area Filled or Shaded (acres) (acres) Phase 1 Adjacent to Springbrook 3 .043 .043 Creek , CSTC Delta 3 .240 .290 C 3 .025 .085 ' D 3 0 .219 Phase 1 Total 308 .637 ' Phase 2 E/F 1 1.010 1.520 ' Some wetland buffer encroachment will occur as a result of the construction of the refined Alternative A. In Phase 1, fill within the buffer area of the wetland adjacent to Springbrook Creek and CSTC delta wetland. Construction of a combination wetpond/biofiltration swale facility within the Wetland D buffer ' Phase I of the refined Alternative A would pass adjacent to east edge of the CSTC riverine wetland. A retaining wall could be provided to prevent roadway embankment from encroaching into this wetland ' area. (A similar impact was noted for Alternative A in the DEIS) The potential impacts to wetlands resulting from activities conducted during construction of Phases 1 and 2 of the refined Alternative A would be similar to the impacts identified for Alternative A in the DEIS, ' except that potential erosion and sedimentation impacts could be less during construction of Phase 2 of the refined Alternative A, since the existing earth embankment will not be removed as proposed for Alternative A in the DEIS. ' Affects on wetlands from stormwater facilities would be less with the refined Alternative A. Wetlands C, D, and the wetland adjacent to Springbrook Creek would not be directly impacted by water quality ' treatment facilities as was noted for Alternative A in the DEIS. Wetlands E, F, G and the south marsh would receive an increased amount treated water from Phases 1 and 2 of the refined Alternative A (similar to Alternative A in the DEIS) because they are currently hydrologically connected. The impact of this increase should not be as great as noted for Alternative A in the DEIS since the existing earth embankment separating these wetlands will be left in place with a box culvert replacing the existing pipe culvert under the existing embankment. Stormwater runoff that currently flows to Wetlands C and D ' would continue to do with the stormwater facilities proposed for Phase 1 of the refined Alternative A. (For Alternative A in the DEIS, this runoff would have been intercepted by Phase 1 stormwater facilities which could have an affect on Wetland C and D hydrology.) ' Final Environmental Impact Statement 2-19 Additional Information No comments were received and no additional information on impacts to wetlands is needed for this EIS. ' 2.3.5.4 Conceptual Mitigation Construction of bridges over wetlands is not proposed for the refined Alternative A in this FEIS. The shading effects on wetlands from bridges result in the same mitigation measures as if they are filled, and bridges are not a cost effective alternative to minimizing wetland impacts. The alignment of the refined Alternative A presented in this FEIS avoids wetland areas to the maximum extent possible so that the impacts from placement of fill within them to support the new roadway will be minimized. Removal of the existing earth embankment south of S.W. 27th Street is no longer proposed as part of the roadway project under the refined Alternative A, thus avoiding any potential impacts to the existing wetlands on each side of the embankment that could result from a reduction in water level. A box culvert is proposed under the existing embankment and new fill embankment to improve hydrology and provide access for wildlife between the adjacent wetlands. Wetland impacts of the refined Alternative A in this FEIS will be addressed through compensatory mitigation (as was proposed for Alternative A in the DEIS). Replacement of wetlands will comply with the requirements of the City of Renton's Wetlands Management Ordinance. Table 2.3.5-2 summarizes the required replacement for mitigating wetland impacts of the refined Alternative A. These values are based on wetland category, vegetation community, and replacement ratios determined for the DEIS. As part of the created wetlands, buffers will be provided to mitigate for impacts to existing wetlands. TABLE 2.3.5-2 WETLAND REPLACEMENT FOR REFINED ALTERNATIVE A Area of Wetland Vegetation Area Filled Wetland Replacement Wetland Area Category Type (acres) Replacement Wetlands Ratio (acres) Phase 1 Construction ' Adjacent to Springbrook Creek 3 .043 1.5:1 .065 Mitigation CSTC 3 Wetland 240 1.5:1 .360 C 3 Emergent .025 1.5:1 .038 Phase 1 Total 0.308 .463 Phase 2 Construction ' E/F 1 Emergent Scrub- 1.010 3:1 3.030 Shrub ' As indicated in Table 2.3.5-2, approximately 0.46 acres of replacement wetland would be needed to compensate for wetland impacts as a result of Phase 1 construction for the refined Alternative A in this i City of Renton 2-20 FEIS Oakesdale Avenue S.W. FEIS, and approximately 3 acres of replacement wetland would be needed as a result of Phase 2 construction for the refined Alternative A in this FEIS. The open field located between the proposed Phase I roadway and Wetlands C and D (see Figure 2.3.5- ' I) identified in the DEIS as the site for Phase I mitigation of Alternative A in the DEIS, will be used for mitigation Phase 1 wetland impacts of the refined Alternative A in this FEIS. Property acquired by the City of Renton specifically for wetland mitigation that is located west of existing Oakesdale Avenue S.W. and abutting the south edge of Wetland G (see Figure 2.3.5-1) is proposed for mitigation of Phase 2 wetland impacts of the refined Alternative A in this FEIS. Per conditions of purchase, this site can only be used for wetland mitigation and open space. The site north of S.W. 27th Street proposed for Phase I wetland mitigation is another potential option for partial or full Phase 2 wetland mitigation, depending on final wetland replacement requirements approved by the City of Renton, Corps of Engineers, and all other federal, state and local agencies with jurisdiction during the design process, and the availability of area at the site. Removal of the existing earth embankment south of S.W. 27th Street is not proposed in the refined Alternative A in this FEIS. Therefore, this removal as a mitigation measure for impacts on Phase 2 wetland functions (as proposed in the DEIS) is no longer an option for the refined Alternative A. Comments were received but no additional mitigation measures are needed to address impacts associated with the refinements to Alternative A in this FEIS. 2.3.5.5 Impact Summary Significant Unavoidable Significant Impacts Mitigation Measures Adverse Impacts Refined Alternative A, Phases 1 and 2 Potential temporary loss of Minimize and mitigate for loss None. wetland acreage and functional of wetland as required by the values as a result of filling and City of Renton. ( R) shading. , Activities affecting wetlands likely subject to Sections 401 and 404 of the Federal Clean Water Act. ( R) ( R) Required mitigation ( 0 ) Optional mitigation No comments were received and no other additional information is needed for this EIS. 2.3.6 Wildlife, Vegetation, and Fisheries 2.3.6.1 Affected Environment Wildlife Numerous swallows nested in the barns once standing on the Longacres Office Park property. , i ' Final Environmental Impact Statement 2-21 Additional Information ' The grassy areas and wetland pastures of the open fields provide foraging habitat for raptors. These areas will be lost as development impact increases. ' Fisheries According to a comment on the DEIS from the Washington Department of Fish and Wildlife, Dolly Varden do not use Springbrook Creek. No other additional information on the affected environment is needed in this EIS. ' 2.3.6.2 Impacts Refined Alternative A Construction Overview Construction of the refined Alternative A in this FEIS will involve clearing, grading, filling, and paving. At the north end of the project, a single-span bridge, 140-feet long would be constructed over Springbrook Creek and an existing wetland adjacent to the west side of the creek. The new roadway ' would cross over the western edge of the CSTC delta wetland on retained fill. At the south end of the project (south of S.W. 27th Street), the roadway would cross City of Renton wetlands, partially on an existing earth embankment adjacent to the wetlands, and partially on new retained fill. Retaining walls are proposed at other locations to minimize roadway fill encroachment on other existing wetland areas. Four stormwater systems will be constructed with water quality treatment and peak discharge control features. As noted above, the existing earth embankment south of S.W. 27th Street will not be removed as part of the refined Alternative A construction. This removal was proposed for Alternative A in the DEIS to 1 provide partial mitigation for loss of flood storage. Phase 1 construction and Phase 2 construction of the refined Alternative A have been revised from the DEIS. See Section 2.2.3, Construction Sequencing, in this FEIS. Vegetation and Wildlife Table 2.3.6-1 presents the approximate amount of vegetation, or habitat, that would be lost as a result of the refined Alternative A in this FEIS and Alternative A in the DEIS. Differences in impacts would occur due to the different roadway alignment, particularly in the northern portion of the project area (Figure 2.2.2-1 in this FEIS). Construction of Phase 1 of the refined Alternative A within the Springbrook Creek riparian corridor would result in 0.4 acres of habitat loss. This includes vegetation removal along the banks of Springbrook Creek for construction of the bridge over the creek and for placement of fill for construction of the roadway approaches at each end of the bridge. On the CSTC wetland mitigation site, approximately 0.8 acres of vegetation and wildlife habitat would ' be lost by placement of fill for the construction of the Phase 1, refined Alternative A roadway within the delta wetland and upland area. Construction in the CSTC wetland mitigation site could require temporary and permanent relocation of several bird nesting structures. These features could be relocated ' to other areas of the wetland for reuse by the same bird species. Construction of the Phase 1, refined Alternative A roadway and stormwater treatment facilities would require removal of approximately 2.6 acres of open field habitat. Impacts on vegetation and wildlife would be similar to those identified for Alternative A in the DEIS. City of Renton 2-22 , FEIS Oakesdale Avenue S.W. TABLE 2.3.6-1 ESTIMATED HABITAT LOSS , Acres Removed Habitat Community Refined Alternative A Alternative A ' (FEIS) (DEIS) Phase 1 , Springbrook Creek Riparian Corridor 0.4 0.7 CSTC Wetland Mitigation Site 0.8 0.4 ' Open Field 2.6 2.8 Phase 2 South Wetlands 1.1 1.1 Southern Forest 0.7 0.7 Total (Phases 1 and 2) 5.6 5.7 Approximately 1.1 acres and 0.7 acres of wildlife habitat in the south wetlands and southern forest, respectively, would be lost as a result of construction of the Phase 2, refined Alternative A roadway (unchanged from the DEIS). The placement of fill within the wetlands for construction of the roadway would account for most of the vegetation removal and habitat loss in these two areas, and reduce the available habitat for those species dependent on wetland and forest habitat (impacts remain unchanged from the DEIS). Wetland loss as a result of filling and grading associated with the construction of Phases 1 and 2 of the refined Alternative A would have the same impacts on small mammals and amphibians as noted for Alternative A in the DEIS. Impacts on wildlife species and habitat, and nesting and feeding disruption due to noise and activities associated with construction of Phases I and 2 of the refined Alternative A would be unchanged from those identified for Alternative A in the DEIS. No comments were received and no additional information is needed for the EIS. Aquatic Resources , No comments were received and no other additional information is needed for the EIS. Impacts of Operation The existing earth embankment in the south wetlands and southern forest will not be removed as part of Phase 2 of the refined Alternative A in this FEIS. The new wider, Phase 2 roadway and traffic flow on it would pose a larger obstacle for wildlife movements. The new roadway would not be a total barrier as a ' box culvert under the new and existing embankment is proposed to provide access between the adjacent wetlands for wildlife. Final Environmental Impact Statement 2-23 Additional Information ' At the north end of the project, Phase I of the refined Alternative A would not divide the open CSTC wetland mitigation site as much as Alternative A in the DEIS, and, therefore could create less of a barrier to wildlife. Other operational impacts on wildlife, and on aquatic resources, resulting from Phases 1 and 2 of the refined Alternative A would remain unchanged from those identified for Alternative A in the DEIS. No comments were received and no other additional information is needed for this EIS. 2.3.6.3 Mitigation Comments were received but no additional mitigation measures are required as a result of these comments, or as a result of impacts associated with the refined Alternative A in this FEIS. 2.3.6.4 Impact Summary Significant Unavoidable Significant Impacts Mitigation Measures Adverse Impacts Creation of a barrier to wildlife Box culvert in Phase 2 project Creation of a barrier to some movements will allow some wildlife wildlife species. movement under the new roadway. Comments were received but no additional information is required as a result of these comments, or as a result of impacts associated with the refined Alternative A in this FEIS. 2.3.7 Land and Shoreline Use 2.3.7.1 Affected Environment ' No comments were received and no additional information is needed for this EIS. 2.3.7.2 Impacts Phase 1 of the refined Alternative A in this FEIS is currently scheduled for construction in 1998 in order to be operational in time to serve new development on the Boeing Longacres Office Park property (which is scheduled to be completed in the fall of 1998). Construction of Phase 2 of the refined Alternative A will occur as soon as funding becomes available. Impacts on Current and Planned Land Uses ITable 2.3.7-1 presents estimated land acquisition for Phases 1 and 2 of the refined Alternative A in this FEIS and for Alternative A in the DEIS. Phase 1 of the refined Alternative A would impact a parking area on the Benaroya Company property (unchanged from impact noted for Alternative A in the DEIS). Phase 1 of the refined Alternative A would impact more of the CSTC delta wetland area and less of the adjacent upland grassy area, than Alternative A in the DEIS. The refined Alternative A proposes to fill the wetland area required for the project. Therefore, acquisition of right-of-way will be required. (Alternative A in the DEIS proposed a bridge over the delta wetland to allow existing land use to continue which may have required only a permanent easement for the new roadway. City of Renton 2-24 ' FEIS Oakesdale Avenue S.W. TABLE 2.3.7-1 LAND ACQUISITION REQUIREMENTS(ACRES) ' OWNER REFINED ALTERNATIVE A ALTERNATIVE A (FEIS) (DEIS) Phase 1 ' Benaroya Company 0.40 0.50 Boeing CSTC 1.50 1.50 , Boeing Longacres Office Park 3.80 3.60 , City of Renton 3.70 3.90 City of Seattle 0.21 0.21 ' Phase 2 Boeing Longacres Office Park 0.50 0.00 City of Renton 1.90 2.40 Note: a Right-of-way easement Land acquisition requirements are estimates based on preliminary plans for roadways, structures and stormwater facilities. Shifting the Phase 1 roadway alignment further to the west near S.W. 27th Street, as proposed by the refined Alternative A, will impact 0.2 acre more of Boeing Longacres Office Park property than ' anticipated with Alternative A in the DEIS. This will reduce the developable area of this site slightly more than Alternative A in the DEIS. City-owned property adjacent to the north side of Springbrook Creek to be acquired for Phase I of the , refined Alternative A would be used for roadway (bridge) purposes. (In the DEIS, this property was also to be used for a biofiltration swale.) City-owned property just north of S.W. 27th Street to be acquired for Phase 1 of the refined Alternative A would be used for roadway, stormwater facilities and wetland ' mitigation (unchanged from the DEIS). Phase 1 of the refined Alternative A will no longer require permanent easements from the Boeing Longacres Office Park and Hunter Douglas (formerly Winmar, Inc.) properties for stormwater facilities. Shifting the Phase 2 roadway alignment further to the west south of S.W. 27th Street, a's proposed by the refined Alternative A, will impact 0.5 acres of Boeing Longacres Office Park property (no impact was anticipated by Alternative A in the DEIS). Most of this property is an existing earth embankment supporting a paved access road which the refined Alternative A proposes to widen, after removal of the road paving, with a retained fill extending into the abutting City-owned wetland area. (Alternative A in the DEIS proposed a bridge and fill for the roadway approaches totally within City-owned property.) Impacts on existing and planned developments in the land use study area as result of Phases I and 2 of ' the refined Alternative A are the same as identified for Alternative A in the DEIS. No comments were received and no other additional information related to impacts on current and planned land uses is needed for this EIS. ' Final Environmental Impact Statement 2-25 Additional Information ' Impacts During Construction and During Operation No comments were received and no additional information is needed for this EIS. ' Cons]stencv with Plans, Policies, and Regulations No comments were received and no additional information is needed for this EIS. ' 2.3.7.3 Mitigation Measures No comments were received and no additional information is needed for this EIS. 2.3.7.4 Impact Summary No comments were received and no additional information is needed for this EIS. 2.3.8 Social Elements 2.3.8.1 Affected Environment Storm Sewer Facilities Other existing storm sewer facilities in the Oakesdale project area not identified in the DEIS include: ' • Two existing storm drain inlets with 6-inch pipe outlets to the west located on the Boeing Longacres Office Park property; one located approximately 100 feet, and the second approximately 200 feet, north of S.W. 27th Street; • A 6-inch culvert under an existing east-west dirt road located on Longacres Office Park Property about 1,000 feet north of S.W. 27th Street; and • Eleven inlets with 6-inch pipe outlets drain an existing paved access road within the Boeing CSTC property north of S.W. 19th Street. Eight inlets outlet to the CSTC "riverine" wetland on the west side of the existing road, and three inlets outlet to the CSTC "delta" on the east side of the roadway. Other Utilitv Features Additional existing utility features located within the corridor of the refined Alternative A in this FEIS include: • An existing irrigation system located within the existing access road and buffer areas adjacent to the "riverine" and "delta"wetlands on the CSTC property. • An underground vault located within CSTC property about 700 feet south of S.W. 16th Street that houses pumps used for aerating the "delta"wetland. ' No comments were received and no additional information regarding the affected environment is needed for this EIS. 2.3.8.2 Impacts Neighborhood Characteristics and Regional and Community Growth jNo comments were received and no additional information is needed for this EIS. City of Renton 2-26 ' FEIS Oakesdale Avenue S.W. Public Services , No comments were received and no additional information is needed for this EIS. Utilities ' See Section 2.3.4 in this FEIS for additional information on impacts to existing drainage systems that convey surface water runoff from the Boeing Longacres Office Park and CSTC properties. ' The refined Alternative A in this FEIS avoids the existing CSTC outlet control structure in the "delta" wetland that regulates the flow of storm water to Springbrook Creek. Therefore, the impacts to this facility resulting from Alternative A in the DEIS will not occur with the refined Alternative A. Potential conflicts and impacts resulting from constructing the refined Alternative A Phase 1 and Phase 2 roadways over the existing King County Metro 72-inch and 108-inch trunk sewers will be similar to ' those identified for Alternative A in Section 3.8, Social Elements, of the DEIS, except as described below. In lieu of the bridge structure and roadway fill at the bridge approaches proposed for Alternative A in the DEIS, Phase 2 construction for the refined Alternative A in this FEIS will include expanding the existing north-south earth embankment with a retained fill extending into City of Renton wetlands. The retained fill will be located over the existing King County Metro 72-inch trunk sewer. (Potential impacts to the 72-inch sewer will be similar to those identified for Alternative A in the DEIS.) Similar potential impacts to the flow and integrity of the 108-inch trunk sewer that could result from constructing a portion of the new Phase 2 roadway on the existing earth embankment are not anticipated. Consolidation of soils over the 108-inch sewer would have already occurred, and, further consolidation from vehicular traffic loads introduced after completion of the Phase 2 roadway should not be significant. Potential impacts to the refined Alternative A Phase 1 and Phase 2 roadways resulting from the presence of the 72-inch and 108-inch sewer lines (maintenance, overflows, settlement of existing backfill over these sewers) will be similar to those identified for Alternative A in the DEIS. Conflicts with the existing 60-inch Cedar River water pipeline and impacts to the City of Renton water lines, hydrants, valves, etc. resulting from Phases 1 and 2 of the refined Alternative A in this FEIS will be similar to those identified in Section 3.8, Social Elements, of the DEIS. Also, impacts to power lines, ' natural gas and fuel oil lines, and telephone facilities resulting from Phases 1 and 2 of the refined Alternative A will be similar to those identified for Alternative A in the DEIS. The refined Alternative A in this FEIS will impact the existing irrigation system on Boeing's CSTC property to the extent that relocation of the section of 8-inch irrigation water line located within the new roadway right-of-way may be required. The refined Alternative A in this FEIS will impact the existing underground vault housing aeration pumps to the extent that relocation of this vault will be necessary. Numerous new utilities (water, sewer, telephone, gas, etc.) are proposed within the refined Alternative A , corridor in connection with Boeing's Commercial Airplane Group Headquarters Building currently under construction on the west side of the new roadway. Extensive coordination with The Boeing Company will be needed to resolve potential conflicts between Boeing's proposed utility systems and the refined Alternative A storm drainage system. No comments were received and no other additional information related to utility impacts is needed for this EIS. Final Environmental Impact Statement 2-27 Additional Information ' Cumulative Impacts No comments were received and no additional information is needed for this EIS. 2.3.8.3 Mitigation The refined Alternative A in this FEIS avoids relocation of the existing outlet control structure in the CSTC delta wetland. Therefore, mitigation identified in the DEIS is not applicable to the refined Alternative A. ' The refined Alternative A in this FEIS may require relocation of a section of 8-inch irrigation water line and relocation of a vault housing aerating pumps, both located on Boeing CSTC property. Relocation of these facilities will be coordinated with The Boeing Company and, if required, will comply with all applicable standards and regulations. The refined Alternative A in this FEIS will not construct a bridge in the Phase 2 segment of the Oakesdale project. Therefore, mitigation in the DEIS related to construction of the Phase 2 bridge is not applicable to the refined Alternative A. Extensive coordination with The Boeing Company will be needed to resolve potential conflicts between Boeing's proposed utility systems for their CAG Headquarters Building currently under construction and the storm drainage system for the refined Alternative A in this FEIS. ' No comments were received and no additional mitigation measures are required to mitigate impacts associated with the refined Alternative A in this FEIS. ' 2.3.8.4 Impact Summary Significant Unavoidable Significant Impacts Mitigation Measures Adverse Impacts Refined Alternative A, Phases 1 and 2 ' Phase 1 would require relocation Relocation will be coordinated None identified. of section of Boeing CSTC with Boeing and will comply irrigation line and vault housing with all applicable standards and Iaerating pumps. regulations. ( R ) Phase 1 will require relocation of Relocation will be coordinated None identified. water lines, hydrants and valves. with Boeing, where applicable, and the City of Renton Water Utility, and will comply with all applicable standards and regulations. ( R ) Relocation will be in conformance with requirements of the City of Renton and Boeing to assure disruptions to service 1 would be minimized. ( R ) City of Renton 2-28 FEIS Oakesdale Avenue S.W. Significant Unavoidable ' Significant Impacts Mitigation Measures Adverse Impacts Refined Alternative A, Phases 1 and 2 Phase I will require relocation of Puget Sound Energy will relocate None identified. I 1 5kV power lines. power lines, where necessary, , and in conformance with their requirements to assure disruptions to service would be , minimized. ( R) Potential settlement and other Design and construction of Phase None identified. impacts to King County Metro 2 fill and retaining structures will 72-inch line resulting from Phase be coordinated with King County 2 construction. Metro. ( R) ( R) Required Mitigation 2.3.9 Transportation No comments were received and no additional information is needed for this EIS. 2.3.10 Parks and Recreation ' 2.3.10.1 Introduction No comments were received and no additional information is needed for this EIS. , 2.3.10.2 Affected Environment , The following clarification to text in the DEIS is in response to a comment received from the City of Renton Community Services: The 0.33 mile segment of the Springbrook Creek trail crossing through the Boeing CSTC site accommodates only the pedestrian user(by agreement between the City of Renton and The Boeing Company). No other additional information is needed for this EIS as a result of refinements to Alternative A in this FEIS. 2.3.10.3 Impacts The sidewalks and bicycle lanes proposed for Phase I of each action alternative (Alternatives A and C) evaluated in the DEIS would provide an alternative north-south pedestrian and commuter bicycle route in addition to (rather than "in lieu of as noted in the DEIS) the Springbrook Trail which is primarily for recreational or pedestrian use. Two additional links to improve pedestrian and bicycle access are proposed as part of Phase I of the refined Alternative A in this FEIS. The missing 300-foot length of sidewalk would be constructed to the east along the north side of S.W. 27th Street between the new Oakesdale Avenue S.W. and the western boundary of the Allpak property. The existing paved access road on Boeing property south of S.W. 27th Street (in the Phase 2 Oakesdale Avenue S.W. project corridor) would be formalized (e.g. signing, pavement markings) to provide an interim pedestrian and bicycle connection between Phase I Oakesdale 1 Final Environmental Impact Statement 2-29 Additional Information ' to the north and existing Oakesdale to the south until Phase 2 of the Oakesdale Avenue S.W. project is constructed. This connection will be subject to the City of Renton obtaining the necessary easement ' rights from The Boeing Company and King County Metro to allow public pedestrian and bicycle use of the existing road. Comments were received but do not require additional information for this EIS. Also, no other ' additional information is needed for this EIS as a result of refinements to Alternative A. 2.3.10.4 Mitigation jNo comments were received and no additional mitigation measures are required to address impacts associated with refinements to the Alternative A in this FEIS. ' 2.3.10.5 Impact Summary No comments were received and no additional information is needed for this EIS. 2.3.11 Visual Resources 2.3.11.1 Introduction,Approach, Visual Resources, Viewer Response No comments were received and no additional information is needed for this EIS. I2.3.11.2 Affected Environment No comments were received and no additional information is needed for this EIS. 2.3.11.3 Impacts During Construction No comments were received and no additional information is needed for this EIS. t2.3.11.4 Impacts During Operation Phase 1 of the refined Alternative A would be located closer to the Boeing CSTC building (as much as 1 90 feet closer) than Alternative A in the DEIS, and the bridge over Springbrook Creek would be several feet higher than the bridge crossing proposed for Alternative A in the DEIS. Therefore, the elevated section of the Phase 1, refined Alternative A would be more of a dominant feature in views from within and outside the CSTC building. Also, traffic on the Phase 1, refined Alternative A elevated roadway over Springbrook Creek would be more visible from within the CSTC building. The Phase 1 refined Alternative A would have similar impacts on views of Springbrook Creek and the natural areas within the CSTC wetland as the Phase 1, Alternative A in the DEIS. The Phase 2 roadway of the refined Alternative A would be ten feet lower than the elevated section of Phase 2 roadway of Alternative A in the DEIS. Therefore, the refined Alternative A roadway and traffic using the roadway would be a less dominant feature in views from: 1) the east on S.W. 27th Street and properties in close proximity, particularly views looking southeast from the Longacres Office Park site; and the Talbot neighborhood located a mile to the east of the new roadway. Shy wildlife species may be impacted by illumination for the new roadway, especially in the Phase 2 project area. No comments were received and no additional information is needed for this EIS. City of Renton 2-30 FEIS Oakesdale Avenue S.W. 2.3.11.5 Mitigation No comments were received and no additional mitigation measures are required to address impacts associated with refinements to Alternative A. ' 2.3.11.6 Impact Summary Significant Unavoidable , Significant Impacts Mitigation Measures Adverse Impacts Phases 1 and 2 of the refined Measures proposed in the DEIS None Alternative A roadway would are applicable No additional block some views. Vehicular measures are required. traffic, signing and lighting would be visible from areas with ' views of the project site. tin Use shielded lighting fixtures None identified Potential for illumination g g , impacts on some wildlife species particularly in wetland areas. 2.3.12 Historic and Cultural Resources No comments were received and no additional information is needed for this EIS. ' 2.3.13 Hazardous Materials No comments were received and no additional information is needed for this EIS. ' t ' Final Environmental Impact Statement 3-1 Comments and Responses 3. Comments and Responses ' This section presents the letters of comment received during the 30-day review period for the Draft EIS and the responses to those comments. Five letters of comment were received, two from State agencies, two from city agencies, and one letter from a group of interested citizens. No comments were received from federal agencies. Comments in each letter are numbered to the right of each comment, with responses to those comments presented on the pages following the letter. Responses, when appropriate, include reference to sections in the Draft EIS, reference to additional information presented in Section 2 of this FEIS, or reference to responses to similar comments elsewhere in this chapter. All parties who submitted comments are identifed below. State Agencies • Washington Department of Ecology May 2, 1997 • Washington Department of Fish and Wildlife May 6, 1997 City Agencies • City of Seattle Public Utilities April 21, 1997 ' • City of Renton Community Services May 2, 1997 Interested Groups/Citizens • Ted Mallory (Friends of Black River) May 7, 1997 3-2 City of Renton FEIS Oakesdale Avenue S.W. ;tars cr ' e s �1 raas ' STATE OF WASHINGTON DEPARTi\AENT OF ECOLOGY P.O. Box 47600 • Olympia, Washington 98504-7 600 (360) 407-6000 • TOO Only (Hearing Impaired) (360) 407-6006 May 2, 1997 ' Mr. Robert Maim City of Renton 200 Mill Ave S IRenton WA 98055 Dear Mr. Mahn: Thank you for the opportunity to comment on the draft environmental impact statement (EIS) for the proposed extension of 0akesdale Avenue Southwest- We have reviewed the document and have the following comments. General comments: The proposed project is in an area of existing flooding and infiltration problems, will P J � � ' cross a waterbcdy with existing water quality problems, and will affect both namraily- occurring wetlands and wetlands created for mitigation. It is also in an area expenencuig a great deal of pressure for development and an accompanying increase in impervious 1 surfaces, stormwater problems, and increased inputs of contaminants. As a result, the permit review for the proposal will require significant assurance that existing water quality and wetland conditions will not be worsened due to individual or cumulative project impacts. The project proponent should be prepared to go beyond standard design criteria to address these impacts. This proposed project should be fully coordinated with other proposals in the area (e.g., the East Side Green River Watershed study, adjacent development proposals, etc.) so that cumulative impacts are anticipated and addressed. tWater Quality: ' The proposed project crosses Springbrook Creek and would discharge stormwater runoff into the creek and into nearby wetlands. Springbrook Creek (WRIA 4WA-09-1015, Class A waters of the state) is on the current 303(d).list of waterbodies exceeding state water quality standards. The standards exceeded include fecal coliform, temperature, dissolved oxygen, sediment bioassay, cadmium, copper, mercury, and zinc. RECEIVED MAY - 6 1997 Transoortadon Syatema C)1v. C� Final Environmental Impact Statement 3-3 , Comments and Responses Mr. Robert Mahn ' May 2, 1997 Page 2 ' As part of the Section 401 review, the proponent must show that the proposed project will ' not result in further exceedances of those standards. The draft EIS (page 3.4-16) states that the stormwater conveyance system, detention facilities, and water quality treatment facilities will comply with local, state, and federal regulations. Table 3.4-6 also states, 2 , that a significant unavoidable adverse impact of the proposed project would be that a percentage of nutrients and metals would enter receiving waters. The project proponent will need to go beyond standard designs and operations for stormwater treatment to ' ensure that the water quality standards in Springbrook Creek that are already exceeded are not further exceeded. Stormwater discharges to wetlands will need to meet state water quality standards, unless, through mitigation sequencing, the impacts of such discharges are avoided, minimized. or 3 , mitigated through an approved wetland mitigation plan. Inte—atin2 Water Ouality and Flood-reiaced Design Features — the proposed project and its increase in impervious surface close to Springbrook Creek will likely result in higher peak storm discharges, reduced concentration times. the need for increased flood conveyance, increased erosion, downstream channel instability, and higher contaminant , loads in a waterbody that already exceeds several state water quality standards. 4 The project proponent should integrate the flood-related design elements required for ' consistency with Rencon's floodulain management ordinance (e.g., zero rise in floodway, compensatory storage for till, etc.) with design elements that will prevent further exceedances of water quality. , Wetlands: Impacts to wetlands due to the proposed project include direct fill, indirect effects such as ' shading, and hydrologic and water quality-related effects such as changes.id the amount of water entering and leaving wetlands and increases of in-water contaminants. All wetland-related impacts will require mitigation through a mitigation plan to be approved by the U.S. Corps of Engineers, Washington Department of Ecology, and oche:state and 5 federal resource agencies. ' We suggest that the mitigation plan include a significant element focused on the Springbrook Creek corridor and the wetlands immediately adjacent to the stream channel. ' Such a plan should be coordinated with other developments and studies in the area to ensure that maximum benefit is derived from the required mitigation. ' 3-4 City of Renton FEIS Oakesdale Avenue S.W. Mr. Robert Mahn May 2, 1997 1 Page 3 1 Tom Luster with our Permit Coordination Team would be happy to assist in resolving these issues. If you have any questions, please call Mr. Luster at (360) 407-6918. ' Sincerely, ' Rebecca J. /�a�n Environmental Review Section RI. cc: Tom Luster, CP NWRO SEPA Coordinator Final Environmental Impact Statement 3-5 ' Comments and Responses Response to Comments from the Washington Department of Ecology 1. This project has been and will continue to be coordinated with the East Side Green River Watershed Project and adjacent development proposals to ensure that cumulative impacts on existing water quality and wetland conditions are anticipated and addressed. Also, the City of Renton will continue to work with all appropriate federal, State and local agencies to provide assurance that existing water quality and wetland conditions are maintained, and where feasible, are improved. ' 2. Stormwater conveyance, detention and water quality treatment facilities will be designed to meet current requirements/standards. The DEIS was recognizing that water quality treatment facilities ' are not 100% effective in removing pollutants. 3. Comment noted. See response to Comment 2, above. 4. As noted in the response to Comment 2, above, the project will include stormwater detention and water quality treatment features to ensure that the issues noted in this comment are mitigated. Integration of these facilities with floodplain impact mitigation will be considered during the project design process. 5. Comments noted. The project will include a wetland mitigation plan that will be approved by all appropriate federal, State and local agencies. Coordination with other developments and studies in the area is anticipated during development of this wetland mitigation plan. ' 3-6 City of Renton FEIS Oakesdale Avenue S.W. f.Are 1w— O £ N 71 State of Washington MAY 1 3 1597 DEPARTMENT OF FISH AND WiLDUFt 1 Maiiino Address: 600 Caoitol Wav N•Clvmpia.WA 98501-1091 •(360)902-2200.TOO(36�� i(DF REN TON Main Office Location: Natural Resources Building-1111 Washington Street Sc•Olymplar' WORKS AOMfN. ' May 6 1997 ' Mr. Gregg Zimmerman Planning/Building/ Public Works Department 200 Mill Avenue South Renton, Washington 98055 Subject: Caksdale Avenue S.W. ,S.W. 16t-h Street to S.W. 31zt Street, Draft Env-ironme tat Impact Statement. Dear Mr. Zimmer-nan: The =ollowinc are my comments regarding this document: ' 1. Surface Water/Quantity and Quality, Pace 3. 4-3, Paragraph 2, Hydraulic Project Approvals (HPA) will be recu,red for the bridge over Springbrook Creek , stormwaLer our-ails and for the discharge of stornwater into Sprincbrook Creek. We will require that stornwater discharge meets the reouirements of the Depart-nents of Ecology Stormwater Manual :or 'Puget Sound. in addition WDF-+d recommends wet pones and bioswales for water quality instead of undercround vaults. D am concerned that the vaults will not get the proper maintenance. 2 Wetlands- Pace 3 .5-1, A.'ADFW also has authority for wetlands associated with Springbrook Creek in addition WDFW wetland policy recuires that if there is a HPA for a 2 ' project than WDF-d will recui,e 2:1 mitigation for all wetland impacts even �-. thev are not associated with Springbrook Creek. B.?roject Construction Overview, ?ace 3.5-8 Last Paragraph-= would recommend and support the removal of the erriban.1ment supporting the paved 3 access road be removed between wetland ? and the South Marsh and wetland F and wetland G. This would provide better access for ar-L-rz_s to utilize this wetland system without crossing roads or going t2hrougR culverts. 3. Wildlife, Vegetation, and Fisheries ' A_.Pace 3. 6-4 , Paragraph 3 - numerous swallows nested in old barns on the 14 Loncacres Office Park Property. B.Pace 3. 6-5, Paragraph 7 - The crass fields and wet'-and pastures provide foraging habitat for raptors. These areas will be lost as development 15 impact increases. 'C. Do1'_v varden do not use Springbrook Creek. 6 Z would like to thank you for the occortunity comment on this document. If ' you have any questions please call me at (206) 391-4365 . Sipcerely, ' ?hilip -chneider cc Ted Muller- WDFW Habitat Biologist Rod Malcomb - Mukelshoot Tribe Jane Banvard- WDFW, Olvmnia Final Environmental Impact Statement 3-7 , Comments and Responses Response to Comments from the Washington Department of Fish and Wildlife (WDFW) ' 1. Comments noted. Page IV in Volume 1 of the DEIS identified HPA as a likely permit required for this project. The project will comply with requirements established by WDFW, including meeting stormwater discharge requirements of the Department of Ecology's Stormwater Manual ' for Puget Sound. The project proposes above ground water quality treatment facilities except where space is limited, necessitating the use of underground vaults. The City of Renton has a maintenance program and staff dedicated to ensuring the proper function of public stormwater facilities in Renton. 2. Comment noted. The current City of Renton Wetlands Management Ordinance, based on the , Washington Department of Ecology's model ordinance, recognizes that wetland mitigation ratios should vary depending on the quality of wetland impacted. The City's ordinance provides that the wetlands affected by Phase 1 of the proposed Oakesdale project (construction north of S.W. ' 27th Street) shall be replaced at a ratio of 1.5:1; those wetlands affected by Phase 2 of the proposed project (construction south of S.W. 27th Street) shall be replaced at a ratio of 3:1. For the total project, the average replacement ratio will be 2.6:1 which meets the 2:1 mitigation ratio ' requirement specified in the WDFW comment. 3. Comment noted. See Section 2.2 of this FEIS for information on the proposed adjustment in the roadway location south of S.W. 27th Street from the location proposed in the DEIS. Under this , new proposal the existing embankment currently supporting the paved access road will be incorporated with a new retained fill to support the new Oakesdale roadway. A single wide, deep, bottomless culvert would be included under the new roadway to provide access for wildlife between wetland areas on both sides of the new road. 4. Comment noted. Information added in Section 2.3.6 of this FEIS. ' 5. Comment noted. Information added in Section 2.3.6 of this FEIS. 6. Comment noted and change made. Information provided in Section 2.3.6 of this FEIS. , 3-8 City of Renton FEIS Oakesdale Avenue S.W. City of Seattle DEVELOPMENT PLANNING Clry pF gFNTOn' Norman B. Rice, Mayor �� z �, I�g, Seattle Public Utilities ' Diana Gale, Director RECEIVED ' April 21, 1997 ' Development Service Division Planning/Building/Public Works Department ' Attn.: Mark R. Pywell, AICP 200 Mill Ave. So. Renton, Washington 98055 Re: Draft Environmental Impact Statement—City of Renton Oakesdale Avenue SW Extension Project— City of Renton File No LUA-95-024 ElS SM Gentlemen: ' In reviewing the above referenced DEIS, and ascertaining how it addresses the Seattle Public Utilities Cedar River Pipeline#4, Seattle Public Utilities (Water Department) requests that the City of Renton include within its DEIS, the following information aoplicable to the Cedar River Pipeline#4. This information was previously submitted to HNTS, Inc., February 13, 1996. Submitted information is required to appear in Section 1.6 Significant Impacts, Mitigation Measures, and Unavoidable Adverse Impacts, subsection "Social Elements "and also in Section 3.3 Social Elements, for both "Alternatives A&' C., The following standards will be required, subject to change depending on final review. 1. The proposed 12 inch storm sewer line'mus:be ductile iron pipe; one length centered over the pipeline. 2. Restrained joints are required within and along the entire right-or-w,ay�pressure tested to watermain standards. 3. The pipeline will need protective slabs, pile supported, where the proposed road crosses ' over Alternate A and/or C. Note: It is absolutely essential that any design of for the proposed roadway facility, in, about and/or upon the location of Seattle Public Utilities 60" Cedar River Pipeline n4, incorporates maximum protection for the intearity of this ' pipeline facility. It is additionally essential that the pipeline be potholed to determine the exact depth and its location prior to construction of the proposed road and supporting facilities ' 4. Show pipeline on the profile drawings for Alternate A and/or C whichever is chosen. ' Dexter Horton Building, 1 Oth floor 710 Second Avenue, Seattle WA 981 CA Tel: (206) 684.5851, TTY/TDD (206) 233-7241, FAX: (206) 684.4631 ea.ucl employment opportunity affirmative action employer. Accommodations for people with disabilities provided on request. 19 • Final Environmental Impact Statement 3-9 , Comments and Responses Page 2 of 2 April21, 1997 Seattle Public Utilities Review DEIS —Cakesdale Ave. SW Extension. It was also determined in our review, and not defined within the DEIS, that Land Acquisition requirements ' necessary to support this activity/project have not been addressed in relation to Seattle Public Utilities Cedar River Pipeline m 4, 30 foot wide, fee owned corridor. It is required and essential that the City of Renton make application for an easement/consent.agreement(s) to build the roadway over Seattle , Public Utilities fee owned property. It will be necessary for any easement document conveying any partial 2 interest in City owned real property to be deliberated upon and approved by the Seattle City Council. As this process may require considerable time for necessary reviews, consideration, document , processing, appraisals and approvals, it would be beneficial for the City of Renton to initiate its acquisition process when reasonably practicable. In continuation of our analysis and recommendations applicable to the above mentioned DEIS, Seattle , Public Utilities requests that the City of Renton include in its Contract Plans all of Seattle Public Utilities existing pipeline facilities. It is additionally requested and required that when any work or proposed use of Seattle Public Utilities fee owned right of way is planned or scheduled within or near the City's pipeline 3 facilities, precise Construction Plans must be submitted to Seattle Public Utilities for review and approval prior to any construction or use activity.As previously alluded to an Easement will be required from Seattle Public Utilities for any such usage. For your convenience, "As Built Construction Plans" are available from , Seattle Public Utilities (Water Department) upon request Your consideration and cooperation in this matter is very greatly appreciated. Should you have any further question please feel free tail me at 684-5970 , Sincerely , William P. Cluckey Real Estate Services cc: 0. Garrison ' 0.Richardson ' 3-10 City of Renton FEIS Oakesdale Avenue S.W. Response to Comments from the City of Seattle Public Utilities ' 1. Comments noted. The City of Renton will work with Seattle Public Utilities regarding the design details necessary for the protection of the 60-inch water pipeline facility. ' 1 Comments noted. Section 3.7.3.2 in volume 1 of the DEIS (page 3.7-11) identifies the easement requirement from the Seattle Public Utilities (Water Department) for the proposed roadway crossing of the 60-inch water pipeline. 1 3. Comments noted. ' Final Environmental Impact Statement 3-11 Comments and Responses R CITY OF RENTON :;7 Community Services MEMORANDUM Date: May 2, 1997 To: Bob Mahn, Civil Engineer III From: Leslie A. Betlach Parks Dire ctor ' Re: Draft Environmental Impact Statement Oakesdale Avenue S.W. S.W. 16th Street to S.W. 31 st Street ' Thank you for providing me the opportunity to review and comment on the Draft Environmental Impact Statement for the above-referenced project. We support Alternative A but would like to comment upon the following areas: 1. In Chapter 1, pages 1-3, Summary, Section 1.4 Alternatives, and on page 1-4, Section 1.4.1, Alternative A, Phase I is described as a four lane road (two in each direction) with a center turn lane/median from SW 16th Street to SW 27th Street. The preliminary landscape plans that have been made available to me for the preparation of a landscape maintenance program describe Phase I as a three lane road from SW 16th ' to SW 27th Streets, with a sidewalk and bike trail on the outside (right-hand) side and landscaping on the outside (right-hand) side (one side only at this time). The phased descriptions of work need to be clarified and/or modified. ' In addition the Phase II description in these sections include a four lane extension with ' a center turn lanelmedian from SW 27th Street to SW 31st Streets. Again the preliminary landscape plans that have been made available to me for the preparation of landscape maintenance program describe Phase II as completing the construction of ' the 2 additional lanes from SW 16th to SW 27th Street with a sidewalk and bike trail on 2 the other outside (right-hand) side and landscaping also again on the outside (right- hand) side. Phase II on these landscape plans additionally includes the construction of ' a four lane road with a center turn lanelmedian from SW 27th Street to SW 31 st Street. (It should be noted that upon completion of Phase II, there would be a bike lane and sidewalk on each side of Oakesdale Avenue). 3-12 City of Renton ' FEIS Oakesdale Avenue S.W. Oakesdale Ave.Extension Project March 5, 1997 Page 2 of 2 Again, the phased descriptions of work need to be clarified and/or modified. 2. In Chapter 3, page 3.10-6, Parks and Recreation, Section, Impact of Operation, , paragraphs 5 and 6, it is suggested that the new bicycle lanes and sidewalks to be constructed as part of the Oakesdale Ave Improvements will provide "alternative north- , south pedestrian and commuter bicycle route (in lieu of the Springbrook Creek Trail) between SW 16th Street and SW 27th Street" and under Phase 11 between SW 27th Street to SW 31 st Street. Please note, this should be "in addition to" the Springbrook Creek Trail along the 3 Springbrook Creek Channel. These two systems serve different functions and user groups and although they should be connected to one another, they can function independently. The Springbrook Creek Trail is primarily for the recreational user (pedestrian oriented), while the proposed bicycle lanes along Oakesdale serve the commuter bicyclist population. It should also be noted that the Springbrook Creek Trail through the Boeing CSTC facility only accommodates the pedestrian user (by agreement between the City of Renton and the Boeing Company). , If you have any questions, please call me at x-5549. I look forward to working with you cc: Jay Covington, Executive Assistant Sam Chastain, Community Services Administrator ' Al Dieckman, Parks Maintenance Manager Gregg Zimmerman, Planing/Building/Public Works Administrator Sandra Meyer, Transportation Director o&usoA2Doc-vs":,"Am2 .- 1 Final Environmental Impact Statement 3-13 Comments and Responses 1 Response to Comments from the City of Renton Community Services 1. Comment and request noted. Information on phasing of the project provided in Section 2.2 of this FEIS. ' 2. See response to Comment 1, above. 3. Comment noted and change made. Information provided in Section 2.3.10 of this FEIS. i 1 i i 1 1 1 1 1 1 1 1 i 1 i 3-14 City of Renton FEIS Oakesdale Avenue S.W. o7"- �El��� AY fi 1997 t e ale �G� /BOG yry p7� C/71Z 1 s Div -7 2 7c',�,l 7Z Final Environmental Impact Statement 3-15 Comments and Responses r v 11 �` y y d2� 1�jG fv47eZ/— slir�lfGe �� �h� ;�o r D S //JI�iCIiTc�/ /1-2 �e �15 Zasr scy 74 7z" 4 �r7` � i� � w�7 S- ci /�✓�/ �� "/Ao/, ram ALSO CvhSTr.ic �io,� i/?1�9G7 S �Dvir]G! %Jess`,, Q 70 5 U,v Ui1 71 S�yri4� yeavj 090 fhe SoU i7 Gt/��/odds z�e 76-2 Sao r�/ V1,4 98/7� ill 3-16 City of Renton FEIS Oakesdale Avenue S.W. Response to Comments from Ted Mallory for Friends of Black River 1. Comment noted. 2. Comment noted. All mitigation identified in the DEIS will be considered for inclusion in the City's Mitigation Document which will set forth the mitigation measures for the project. 3. Comment noted. Section 3.10.4 in Volume I of the DEIS (page 3.10-7) identifies relocation of the Springbrook Creek Trail as a measure to mitigate the proposed project's impacts on the Trail. This measure will be considered for inclusion in the City's Mitigation Document. 4. The lowering of the water surface by as much as one foot noted in the DEIS was estimated to occur for a 2-year storm event. Normal hydrology (depth and duration of inundation) of the south wetlands should not be impacted by removal of the existing earth embankment. However, ' as described in Chapter I of this FEIS, the current project proposal is to retain the existing embankment and incorporate it with a new retained fill to provide support for the new Oakesdale roadway. A single wide, deep, bottomless culvert would be included to provide access for wildlife between the south wetlands. This culvert will be designed to maintain the existing outlet elevation and minimize impacts to the normal water level in the south wetlands. 5. Comment noted. Pile driving is no longer proposed as a method of construction for the project. ' Sections 3.6.4 and 3.6.5 of Volume 1 of the DEIS (pages 3.6-11 and 3.6-12) identified timing of construction activities as a measure to mitigate impacts during the wildlife nesting and rearing season. This measure will be considered for inclusion in the City's Mitigation Document. 6. Comment noted. Information provided in Section 2.3.11 of this FEIS regarding the use of shielded lighting fixtures as a measure to minimize illumination impacts on shy wildlife species in the wetland areas of Phase 2 as well as Phase 1. This measure will be considered for inclusion in the City's Mitigation Document. r