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SWP273218(8)
SEPA Environmental Review Application ' Strander Boulevard Extension Project City of Renton September 2004 = 22 - GEOTECHNICAL REPORT .................................................................................................................................................... c The attached Geology and Soils Technical Discipline Report addresses the requirements ' for this section of the application. .......................................................................................................................................................... DEV ciTOvOF RENTOPLAN LNG OCT 1 12004 k EIVED 22-1 Perteet Inc. DRAFT 1 GEOLOGY AND SOILS TECHNICAL DISCIPLINE REPORT Strander Boulevard Extension Project May 2004 i 1 Prepared For: City of Renton Department of Public Works Renton City Hall 1055 S. Grady Way Renton, WA 98055 Prepared By: Shannon & Wilson, Inc. 400 North 34th Street, Suite 100 Seattle, WA 98103 (206) 632-8020 DRAFT TABLE OF CONTENTS 1.0 INTRODUCTION .....................................................................................................3 1.1 PROJECT ORGANIZATION AND SCOPE........................................................................ 3 1.2 STUDY AREA............................................................................................................. 3 1.3 PROJECT BACKGROUND ............................................................................................ 6 1.4 PROJECT PURPOSE..................................................................................................... 8 ' 1.5 PROJECT NEED.......................................................................................................... 8 2.0 DESCRIPTION OF ALTERNATIVES................................................................. 10 2.1 ALTERNATIVES CONSIDERED................................................................................ 10 3.0 METHODOLOGY AND COORDINATION....................................................... 16 3.1 EVALUATION CRITERIA........................................................................................... 16 3.2 APPROACH TO ANALYSIS ........................................................................................ 17 3.3 COORDINATION WITH AGENCIES AND JURISDICTIONS............................................. 28 3.4 POLICIES AND APPROVALS...................................................................................... 28 4.0 AFFECTED ENVIRONMENT..............................................................................30 4.1 PROJECT STUDY AREA DESCRIPTION AND TOPOGRAPHIC SETTING......................... 30 4.2 GEOLOGIC CONDITIONS .......................................................................................... 31 4.3 PROJECT STUDY AREA GEOLOGY............................................................................ 31 ' 4.4 HYDROGEOLOGIC REGIME ...................................................................................... 37 4.5 SOIL AND GROUNDWATER DESCRIPTION OVERVIEW .............................................. 37 4.6 TECTONICS AND SEISMICITY ................................................................................... 38 4.7 GEOLOGIC HAZARDS AND CRITICAL AREAS ........................................................... 39 5.0 IMPACT ANALYSIS..............................................................................................46 5.1 NO ACTION ALTERNATIVE...................................................................................... 47 5.2 ALTERNATIVE 1: CONSTRUCTION OF A ROADWAY OVERPASS CROSS-VALLEY LINK, RELOCATION OF THE UNION PACIFIC RAILROAD TRACK,AND MODIFICATION OF SW 27TH STREET TO FIVE LANES......................................................................................... 50 5.3 ALTERNATIVE 2: CONSTRUCTION OF A ROADWAY UNDERPASS CROSS-VALLEY LINK,RELOCATION OF THE UNION PACIFIC RAILROAD TRACK,AND MODIFICATION OF SW 27TH STREET TO FIVE LANES.................................................................................. 57 5.3 ALTERNATIVE 2: CONSTRUCTION OF A ROADWAY UNDERPASS CROSS-VALLEY LINK,RELOCATION OF THE UNION PACIFIC RAILROAD TRACK,AND MODIFICATION OF SW 27TH STREET TO FIVE LANES.................................................................................. 65 6.0 COMPARISON OF ALTERNATIVES................................................................. 67 ' 7.0 REFERENCES......................................................................................................... 71 Draft Geology and Soils Discipline Report i May 2004 Strander Boulevard Extension City of Renton DRAFT Page LIST OF TABLES TABLE 4.1: AREMA PERFORMANCE CRITERIA LIMIT STATES............................................ 39 TABLE 4.2: ESTIMATED ELEVATION IN FEET OF POTENTIAL LIQUEFACTION BY AREMA PERFORMANCE CRITERIA LIMIT STATE ..................................................................... 44 TABLE 4.3: ESTIMATED LIQUIFACTION INDUCED GROUND SETTLEMENT IN INCHES......... 44 TABLE 4.4: EROSION HAZARD UNITS................................................................................ 4$ TABLE 6.1: SUMMARY OF POTENTIAL IMPACTS TO GEOLOGY AND SOILS......................... 68 LIST OF FIGURES FIGURE1.1: LOCATION MAP...............................................................................................4 FIGURE 1.2: TYPICAL ROADWAY SECTION.......................................................................... 5 FIGURE 1.3: PROJECT SEGMENTS ........................................................................................ 7 FIGURE 2.1: PROPOSED ROADWAY LIMITS........................................................................ 11 FIGURE 3.1: SITE AND EXPLORATION PLAN...................................................................... 18 FIGURE 3.2: GEOLOGIC MAP............................................................................................. 29 ' FIGURE 4.1: GENERALIZED SUBSURFACE PROFILE A-A.................................................... 32 FIGURE4.2: SOILS MAP .................................................................................................... 42 FIGURE 4.3: HAZARDS MAP.............................................................................................. 43 LIST OF APPENDICES APPENDIX A: SUBSURFACE EXPLORATIONS APPENDIX B: IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL/ENVIRONMENTAL REPORT Draft Geology and Soils Discipline Report ii May 2004 Strander Boulevard Extension City of Renton r DRAFT 1.0 INTRODUCTION 1.1 Project Organization and Scope The purpose of this discipline report is to present an evaluation of the potential impacts of developing an extension of Strander Boulevard/SW 27th Street from West Valley Highway eastward to East Valley Road on geology and soils. The report evaluates impacts to geology and soils in the area where construction would take place as well as for a wider area where secondary and/or cumulative impacts may occur. 1.2 Study Area This project study area is located within the jurisdictions of both the City of Renton and the City of Tukwila in Section 19, Township 23 North, Range 5 East; Sections 24 and 25, Township 23 North, Range 4 East; Section 30, Township 23 North, Range 5 East(See Location Map, Figure 1.1). Renton is located at the south end of Lake Washington on the edge of metropolitan and rural King County. Its location between Seattle, Tacoma, and Bellevue places Renton in the center of a region that is the economic hub of the state. Renton encompasses approximately 16.7 square miles. Renton and Tukwila are at the crossroads of a regional transportation network where seven state and interstate highways converge and which is central to national and international air traffic. The study area is sideways T-shape. It includes the area between the west side of the Interurban Trail and the east side of the Burlington Northern Santa Fe (BNSF)railroad track. The study area is wider in the vicinity of Strander Boulevard because it is possible that the trail would be moved. The southern boundary is south of a railroad spur heading northwest from the Union Pacific Railroad (UPRR) mainline (the spur that crosses the Green River, not the short spur that serves adjacent businesses), which is about 1,700 feet south of Strander Boulevard. The spur would be the approximate takeoff point for a new UPRR mainline track that would replace the existing track. The new track would parallel the existing BNSF tracks. On the north end,the study area extends just past I-405 where the UPRR track begins to parallel the BNSF tracks. East of the BNSF tracks, the bulk of the proposed project construction in the primary study area would be confined to the Strander/27th Avenue corridor, branching off at the points where the Boeing access roads and Sounder station access are to be located. From Oakesdale to East Valley Road, the expectation is to widen the existing roadway within the right-of-way limits. The new roadway would be five lanes with sidewalks and planter strips on both sides (See Figure 1.2). The intent is to keep the project within City right- of-way. Draft Geology and Soils Discipline Report 3 May 2004 Strander Boulevard Extension City of Renton r Seattle, ' .y Elliot Bay Lake Washington Bellevue " m Mercer Island i i f Puget Sound TukwU Renton V a II� Seal Tac 0 60 0 Q Q D o a 4 Project-Location Kent Des Moines Q � - East Passage Auburn CV e 4 Federal Way 1 Toma d RE N T O N City of Renton Figure 1 .1 Strander Boulevard Extension Perteet Engineering, Inc. Location Map 1 Civil,Transportation and Surveying rr rr rr r rr r rr rr �r rr rr rr r rr rr err ri rr �r 1 ' U rt M � ly, o � 43 oo � I 4 z STRANDER BOULEVARD EXTENSION : TYPICAL ROADWAY SECTION (n 0 v � Q- 90' ROW (D QJ cD 0 G' PLANTER 60 G' PLANTER � � I < G' SIDEWALK 12' 12' 12' 12' 12' 12' Q' THKU LANE THRU LANE TURN LANE THKU LANE THRU LANE SHARED X �� USE PATH (D ,1 70 AM ♦ 4 b♦ 4 �+ r� WIDEN WITHIN THE ROW a) a) WITH SHARED USE PATH Q- ON SOUTH SIDE -< G, C (D (D 0 � 0 N DRAFT 1.3 Project Background J b This project began with the formation of the Project Stakeholder Committee composed of public agencies and private businesses. Members of the committee have some insight concerning the needs of this project, opportunities that this project could promote, and potential transit and commuter rail improvements it could provide for the Tukwila commuter rail station. The Project Team facilitated Project Stakeholder Committee meetings with affected agencies, such as WSDOT; City of Renton; City of Tukwila; King County; and private businesses, including Boeing, BNSF, and UPRR. Concurrently,the Project Team reviewed existing information regarding the corridor and the existing environment and infrastructure within the project corridor. The Project Team assembled information about to potential corridor concepts, existing and projected traffic that would be generated by the proposed corridor improvements, affected environment, and costs. The Project Stakeholder Committee, formed by the City of Renton, became a source of guidance and input with regard to the information assembled for the potential corridor concepts by the Project Team. The role of this committee was to review and comment on the major study tasks and to recommend preferred concepts. The committee met seven times during this phase of the project and provided the Project Team their endorsement to the Project Team's preliminary recommendation for each of the three proposed segments I (See Figure 1.3): • Segment 1 —West Valley Highway to Oakesdale Avenue SW • Segment 2—Oakesdale Avenue SW to East Valley Highway • Segment 3 —added access to SR 167 via East Valley Road At the conclusion of the study,the City of Renton determined that construction of Segments 1 and 2 by themselves would provide a vital cross-valley route and have substantial utility independent of Segment 3. The Project Team prepared a statement of the problem based on a review of existing traffic volumes, projected 20-year traffic volumes, economic growth projections from the cities of Renton and Tukwila, and committee member discussions. There were initially 13 potential concepts for Segment 1, 5 potential concepts for Segment 2, and 4 potential concepts for Segment 3. Each of these concepts was described in a conceptual level of detail. At this level of definition, the corridor improvements included sketches, key physical and operational features, functions, benefits, and potential impacts to the environment. i Draft Geologyand Soils Discipline Report 6 May 2004 P P Y Strander Boulevard Extension City of Renton 1 i N � GALLEY SW 7TH ST SS 7 1 \ >a S 1 ST T 15, INTERURBAN S / 't AVE S y P( SW 16TH i ST kP � 1 11 BLVD PKWY wl = SEGMENT 1 Y SEGMENT 2 _ Q ! a �` BLVD \ u SW 2 STRANDER k BLVD t - "J I w � g CO SW 34TH ST J W af 1 SEGMENT 3 a w of of a O O a > - SW 41TH ST o ; 0 z a S T 180TH ' ST SE 43RD ST I ,\ (S 180TH ST) RE N T Q City of Renton Figure 1 .3 _ - Strander Boulevard Extension Perteet Engineering, �nc. Project Segments Civil,Transportation and Surveying DRAFT The Project Team evaluated the concepts through a first-level screening, which was J p g g essentially a"fatal flaw" analysis. Concepts were recommended for elimination if they contained serious flaws, were likely to perform poorly, demonstrated an undesirable combination of performance and adverse impacts, or did not appear to meet the committee's committed goal for the project. Following the initial screening, a second screening was conducted on the concepts not eliminated. During the second-level screening, a more detailed evaluation was applied using additional criteria related to ' transportation performance, land use/social impacts, environmental impacts, and cost/feasibility. A final screening was conducted on the last remaining concepts using the same criteria as the second screening but with additional information collected, as well as the results of a traffic analysis on the effects of adding this east-west corridor between SW Grady Way and South 180th Street/SW 43rd Street. In addition, more detailed costs of the concepts were discussed and the potential for funding the concept and the overall financial viability of a concept were evaluated. During each of the evaluation screenings, the Project Stakeholder Committee was briefed on the evaluation. Upon endorsement by the Project Stakeholder Committee, the Project Team continued to the next level of evaluation. The final screening resulted in a preliminary recommendation for each segment by the Project Team. The Project Stakeholder Committee has concurred with this preliminary recommendation. 1.4 Project Purpose The purpose of this project is to improve travel speed, reliability, and access in the north Renton/south Tukwila area. This would be accomplished by adding a new roadway segment from Strander Boulevard to SW 27th Street and roadway improvements along SW 27th Street. This would result in a cross-valley link between West Valley Highway (SR 181) and East Valley Road via Strander Boulevard in Tukwila and SW 27th Street in Renton. 1.5 Project Need The proposed project would meet several needs important to both Renton and Tukwila. The project would: • Decrease travel time and increase reliability • Relieve congestion • Provide access to the future Sound Transit Tukwila Station • Improve freeway operation ' Encourage transit-oriented development • Promote freight mobility and economic development 1 Draft Geology and Soils Discipline Report 8 May 2004 Strander Boulevard Extension City of Renton DRAFT 1.5.1 The Need to Decrease Travel Time and Increase Reliability The absence of a direct route to and from the project area between West Valley Highway and SR 167 results in extra travel time for freight shippers, transit vehicles, and general purpose vehicles. A grade-separated route crossing the UPRR and BNSF tracks would both decrease travel times and increase the certainty that vehicles would not be delayed by trains traveling through the area. ' 1.5.2 The Need to Relieve Congestion In order for traffic from Strander Boulevard to cross the UPRR and BNSF tracks and connect with East Valley Road, vehicles must either travel approximately .6 miles north on West Valley Highway to SW Grady Way and then east or go more than a mile south to SE 180d' Street/SW 43`d Street before going east. In either case,the circuitous route causes unnecessary congestion that would be alleviated by a direct cross-valley connection. 1.5.3 The Need to Provide Access to the Future Sound Transit Tukwila Station The Boeing Longacres site currently facilitates one of south King County's highest proportions of vanpool users at a temporary Sound Transit station. The temporary station will eventually develop into the Sound Transit Tukwila Station and will become an 1 important intermodal center for the South King County area. Current routes from the temporary facility to the freeway system are convoluted and congested. Improved access to this commuter rail station will encourage transit use, and help to relieve traffic congestion in the region. Improved access would result in shorter commute times for high-occupancy vehicle (HOV)users, and keep the use of alternative modes of transportation high. 1.5.4 The Need to Improve Freeway Operation ' Due to high traffic volumes, it is difficult for HOV and freight traffic on 1-405, SW Grady Way, and SW 43rd Street to access important employment and industrial centers in the Green/Duwamish River valley. Bus movements across congested SR 167 traffic lanes between the inside HOV lanes and on- and off-ramps at the outside lanes increase travel times for HOVs and contribute to general purpose traffic congestion. By providing an additional cross-valley link, the proposed project would take some traffic off of I-405 and SR 167. ' 1.5.5 The Need to Encourage Transit-Oriented Development If the UPRR tracks are relocated to more closely parallel the BNSF tracks through the project area, additional land could be made available for economic development in Tukwila adjacent to the planned Sound Transit Tukwila commuter rail station. The location would be ideal for Transit Oriented Development(TOD) and would reinforce Draft Geologyand Soils Discipline Report 9 May 2004 P P Y Strander Boulevard Extension City of Renton i DRAFT topportunities for development and growth within the Boeing Longacres site and surrounding areas. 1.5.6 The Need to Promote Freight Mobility and Economic Development Fast, reliable freight access to industrial areas in the Green/Duwamish River Valley is crucial to economic development in the area; without such access, businesses could suffer and may choose to relocate. The extension of Strander Boulevard from West Valley ' Highway (SR 181)to SW 27th Street would improve access to SR 167, thus providing an alternative to the existing freight routes in the area. In addition to reducing travel time, the new facility may also reduce congestion in the area by drawing vehicles from other truck routes, thus reducing the overall congestion level in the area. Additional access to the future development of the Boeing Longacres site is equally important to the economic development currently projected and being planned. Without improved local and through access, the rate at which new and existing businesses choose to locate or expand here is likely to be significantly reduced. 2.0 DESCRIPTION OF ALTERNATIVES 2.1 Alternatives Considered Three action alternatives and a No Action alternative are evaluated in this report. The alternatives focus on a cross-valley link between West Valley Highway (SR 181) and ' East Valley Road (see Figure 2.1) that would begin at the signalized intersection of Strander Boulevard and West Valley Highway on the west and would terminate at the unsignalized intersection of SW 27th Street and East Valley Road on the east, a distance of 6,500 feet. At present, West Valley Highway to Oakesdale Avenue SW is an unimproved area with no roadway that directly connects Strander Boulevard with the area to the east. From Oakesdale Avenue SW to East Valley Road,there is an existing roadway approximately 3600 feet long. The project alternatives focus on strategies to cross the unimproved area, especially railroad tracks owned and operated by Union Pacific Railroad (UPRR) and Burlington Northern Santa Fe Railway (BNSF). 2.1.1 No Action Alternative The No Action alternative would keep the project corridor as it currently exists. No new roadways would be constructed or improved in the corridor. The purpose and need for the project would not be met by the No Action alternative. Draft Geologyand Soils Discipline Report 10 May 2004 P P Y Strander Boulevard Extension City of Renton SEC. 19, T 23N, R 5E, W.M. a� S C. 25, T 23N, R45E, M. LANGSTON RD f AIRPORT . 1 T i ��'• S 133RD STD S 132N ST S '7•(y�, ,•yam`E1\ P i / CITY LIMIT_S b s 0 LAVACLFY KWy SW 7TH ST v3 S� 7 Of S SPRINGBR K I 147TH sr TRAIL a i_n a Np 151ST Sr 4 k_ tF IN?ERURBAN `s if' o Z SW 51iI Si . s �ry�e�rFR BwD Q T uKW1 L A w LONGACRES AY P R P O E D i ?KWY � a. a Y RO D AY LIMITS 0 0 z ' SPRINdBROOK —i Z ��� TRAIL i;.... ¢ STRANDER ¢ BLVD 3, - > < � ST.R.v NDER - - --SW 27TH - <I B` �— BNSF TkACKS( W UPRR T� CK(1) z g Si 0 3 N H j W 34TH ST Uj of Y W Q b co y W� � Y r < 0¢ O a S < , SW 41TH ST yid O sr <S 180TH ST s 1 S ST Se 43RD ST INTE / TRAIL RE �' r ( N City of Renton Figure 2.1 Strander Boulevard Extension 9 Perteet Engineering, Inc. Proposed Roadway Limits Civil,Transportation and Stu-veying DRAFT 2.1.2 Alternative 1: Construction of a Roadway Overpass Cross-Valley Link, Relocation of the Union Pacific Railroad Track, and Modification of SW 27th Street to Five Lanes Alternative 1 would create a link between West Valley Highway Hi SR and Oakesdale Y ( 181) ' Avenue SW with a single overcrossing of both the UPRR and BNSF tracks. From Oakesdale Avenue SW to East Valley Road, SW 27th Street would be widened and include pedestrian facilities and landscaping. Alternative 1 would include five elements: • Relocation of the Union Pacific Railroad track • New roadway construction from West Valley Highway to Oakesdale Avenue SW • Improvements to SW 27th Street • Modifications to the Interurban Trail • Modifications to South Longacres Way Relocation of the Union Pacific Railroad Track ' The UPRR track would be shifted to the east to parallel the existing two sets of BNSF track. To develop this alternative, a new railroad track would be constructed within a new 100-foot right-of-way adjacent to the BNSF right-of-way and then joined with the existing UPRR track at both ends of the project area. Approximately 5,500 feet of new track would be constructed at an elevation similar to that of the existing BNSF tracks. ' Construction would require placement of 125,000 cubic yards of earth and gravel for the new railroad bed. The new UPRR track would be located at the center of the new 100- foot right-of-way. Approximately the same amount of track and railroad bed would be ' removed from the existing UPRR location as will be constructed at the new UPRR track location. The railroad bed material would be disposed of at an approved location or reused as a construction fill material. Construction would be sequenced so that disruption of railroad service would be avoided or minimized. With this alternative, the new UPRR track can be constructed while ' service is continuing on the old track. When the new track is completed, UPRR train traffic would be moved to the new track,the existing UPRR track and railroad bed would be removed, and construction of the roadway overpass would begin. New Roadway Construction from West Valley Highway to Oakesdale Avenue SW A new roadway would be constructed from the intersection of West Valley Highway(SR 181) and Strander Boulevard to the intersection of Oakesdale Avenue SW and SW 27th Street. The roadway alignment would be an extension of Strander Boulevard and curve to match up with the existing alignment of SW 27th Street. Alternative 1 would feature an overpass that would be constructed over the two existing ' BNSF tracks and the new UPRR track. The overpass would provide a net vertical clearance of 17 feet and include four travel lanes, a sidewalk on the north side, and a 1 Draft Geology and Soils Discipline Report 12 May 2004 Strander Boulevard Extension City of Renton i DRAFT shared use path(combined bicycle/pedestrian path) on the south side for pedestrians and bicycles. From West Valley Highway to the overpass,the roadway would consist of five lanes (four thru lanes and a two-way left turn lane), landscaped strips, a sidewalk on the north side, and a shared use path on the south side. Bicycle facilities would be provided in either combined travel lanes/bicycle lanes or as a shared use path. The landscaped strips would be provided between the traveled way and the pedestrian facilities, and in some ' locations where a two-way left turn lane is not needed, a landscaped median would be provided. The overpass would not have the two-way left turn lane and planter strips. From the overpass east to Oakesdale Avenue SW, the same five-lane roadway, landscape strips, and pedestrian/bicycle facilities would be constructed. This section (including the roadway,pedestrian facilities and landscaped strips) would be 90 feet wide from back of sidewalk to back of sidewalk, staying, for the most part, within the appropriate existing ' City-owned right-of-way. The new roadway construction would result in three new intersections between West ' Valley Highway to Oakesdale Avenue SW. There would be one intersection at the future Sound Transit Tukwila Station access road, and two intersections that would result from access roads to the Boeing Longacres site. New traffic signals would be installed at each ' of these intersections. Improvements to SW 27th Street ' The existing section of roadway between Oakesdale Avenue SW and East Valley Road would be widened to match that of the new roadway segment to the west(five lanes, landscaping strips, and pedestrian/bicycle facilities on each side). The section would be 90 feet wide from back of sidewalk to back of sidewalk, staying, for the most part, within existing City-owned right-of-way. At some locations where there are space constraints or the need to avoid wetland impacts,the planter strip may be eliminated. Portions of the north side and south side of the proposed improvements may require a 3-to 8-foot block or rock wall at the back of the sidewalk to minimize impacts to the adjacent wetlands. A ' handrail would be required along the top of these wall sections. Modifications to the Interurban Trail ' The new roadway g g segment linking West Valley Highway and Oakesdale Avenue SW would cut across the Interurban Trail. As a result, it would be necessary to construct a new means of making the trail continuous. The least obtrusive and preferred route is to have an at-grade crossing at either West Valley Highway or at the future Tukwila Station access road intersection. On the north side and the south side of the roadway,trail users ' would be routed onto the new bicycle/pedestrian facilities along the roadway, directed toward the intersection, cross the intersection, and then be directed back to the existing trail. Draft Geologyand Soils Discipline Report 13 May 2004 P P Strander Boulevard Extension City of Renton DRAFT ' Modifications to South Longacres Wa a y ' South Longacres Way, which is approximately 1,700 feet north of the intersection of Strander Boulevard and West Valley Highway, is bridged by the UPRR track and the BNSF tracks. It currently provides access to the temporary Sound Transit commuter rail parking area. The existing railroad bridges over South Longacres Way are narrow and have clearances that are below the minimum requirements. As a result of this project, if ' South Longacres Way were to continue to remain open, improvements would have to be made to provide minimum vertical clearances. A new UPRR bridge structure would have to be built, improvements would need to be made to the BNSF bridge structure, and the ' vertical profile of South Longacres Way would have to be lowered. 2.1.3 Alternative 2: Construction of a Roadway Underpass Cross-Valley Link, ' Relocation of the Union Pacific Railroad Track, and Modification of SW 27th Street to Five Lanes Alternative 2 would create a link between West Valley Highway and Oakesdale Avenue SW with a single underpass of both the UPRR and BNSF tracks. As described previously for Alternative 1, the UPRR track would be relocated to the east to parallel the existing BNSF tracks. The roadway would be the same as Alternative 1 and have the same five elements as Alternative 1, listed below: ' Relocation of the UPRR track • New roadway construction from West Valley Highway to Oakesdale Avenue SW • Improvements to SW 27th Street • Modifications to the Interurban Trail • Modifications to South Longacres Way ' Relocation of the Union Pacific Railroad Track ' This project element would be the same as for Alternative 1; however, constriction sequencing would be different. ' Construction would be sequenced so that disruption of railroad service would be avoided or minimized. The construction of the new railroad track and the roadway underpass (see new roadway construction subsection below) would also be constructed simultaneously. ' When the new track is completed, train traffic from the western BNSF tracks would be temporarily shifted to the new track and construction of the underpass beneath the unused tracks would take place. After completion of the second section of the underpass, train traffic from the eastern BNSF track would be temporarily shifted to the western track, and the third section of the underpass would be constructed under the eastern BNSF ' track. When the underpass is completed, BNSF train traffic would be shifted back to their two original tracks, and UPRR train traffic would be relocated to the new track, and the existing UPRR track and railroad bed would then be removed. ' Draft Geologyand Soils Discipline Report 14 May 2004 P P Y Strander Boulevard Extension City of Renton DRAFT ' New RoadwayConstruction from West Valle Highway to Oakesdale Avenue SW f y a y This project element would be the same as Alternative 1, except that an underpass of all three railroad tracks (the relocated track used by UPRR and the two BNSF tracks) would ' be constructed rather than an overpass. The underpass would provide 17 feet of a net vertical clear distance between the roadway and the bottom of the bridge structure and would contain all of the same roadway elements as in Alternative 1. ' Other elements of Alternatives would be walls along the underpass and in other various locations and the construction of water quality treatment and detention facilities. The ' underpass section would include a pump system to remove the accumulated rainwater. Improvements to SW 27th Street This project element would be the same as for Alternative 1. Modifications to the Interurban Trail This project element would be the same as for Alternative 1. Modifications to South Longacres Way This project element would be the same as for Alternative 1. 2.1.4 Alternative 3: Construction of a Roadway Underpass Cross-Valley Link, Union ' Pacific Railroad Track Not Relocated, and Modification of SW 27th Street to Five Lanes As with Alternative 2, Alternative 3 would create a link between West Valley Highway and Oakesdale Avenue SW with a single underpass of both the UPRR and BNSF tracks. Alternative 3 differs from Alternatives 1 and 2 because the UPRR track would not be relocated to the east to parallel the existing BNSF tracks. For this alternative,the UPRR track would remain in their existing location. The roadway would be the same as that for Alternative 2 and would have most of the same elements as Alternative 2: ' New roadway construction from West Valley Highway to Oakesdale Avenue . SW ' Improvements to SW 27th Street • Modifications to the Interurban Trail . Modifications to South Longacres Way New Roadway Construction from West Valley Highway to Oakesdale Avenue SW ' Under Alternative 3, this project element would be the same as Alternative 2 except that the length of the underpass would be longer because of the different location of the railroad structures. The longer underpass would result in the purchase and modification to the existing parcels and businesses on the northeast and southeast corners of the intersection of Strander and West Valley Highway. Changes would have to be made to Draft Geologyand Soils Discipline Report 15 May 2004 P P Y Strander Boulevard Extension City of Renton i DRAFT ' these lots so that the driveways could match into the new roadway, which would be at a lower elevation than the existing roadway. All other elements of the project that would result from the Alternative 3 would be the same as Alternative 2. Improvements to SW 27th Street ' This project element would be the same as for Alternative 1. Modifications to the Interurban Trail ' This project element would be the same as for Alternative 1. Modifications to South Longacres Way With Alternative 3, there would be no required modifications to South Longacres Way because no changes would be made to the existing UPRR or BNSF tracks. 3.0 METHODOLOGY AND COORDINATION 3.1 Evaluation Criteria Information about the geologic subsurface conditions along the proposed alignments for Alternatives 1, 2, and 3 (affected environment)was evaluated by reviewing existing available subsurface information and by performing subsurface explorations. Available subsurface information was collected from files maintained by the City of Renton, the City of Tukwila, Boeing Company, and Shannon& Wilson, Inc. project files. Most of ' the existing information was compiled during a previous preliminary study, Phase 1, done for Berger/Abaco (Shannon& Wilson, 2001). In addition, the City of Renton forwarded subsurface information from the ConocoPhillips Renton Terminal (tank farm) on SW 27th Street. Information from published geologic maps and other documents was also reviewed. During the previous Phase 1 preliminary study, a geologic reconnaissance of the alignment area was also completed. ' The information collected from the data review, geologic eolo is reconnaissance, and subsurface explorations was used to develop a description of the affected environment including ' geology, location of critical geologic areas, and general topographic setting. A description of the affected environment based on these studies is presented in Section 4 of this report. Based on the No Action alternative and Alternatives 1, 2, and 3, geologic and ' geotechnical impacts were assessed related to cuts and fills, retaining walls, foundations, liquefaction (as defined in Section 4.7.3), fill settlement, erosion and sediment transport, groundwater uplift pressures, construction, and utilities. Mitigation measures for these ' impacts are proposed and are included in Section 5 of this report. Draft Geology and Soils Discipline Report 16 May 2004 ' Strander Boulevard Extension City of Renton DRAFT 3.2 Approach to Analyses 3.2.1 Studies Geologic data were obtained for Alternatives 1, 2, and 3 by collecting and reviewing existing data,performing a geologic reconnaissance, drilling 17 soil borings and installing several monitoring wells and/or vibrating wire piezometers, taking monthly ' groundwater readings, taking groundwater readings at 30-minute intervals for 2.5 months in the boring nearest to the Green River, and performing slug testing in the monitoring wells to estimate hydraulic conductivity. The geologic evaluation of the proposed Build alternatives was performed based on these data. Preliminary evaluations were made related to foundation axial capacities, liquefaction, lateral earth pressures on the underpass sidewalls, and other geologic issues. The evaluations were made based on experience with similar projects and similar soil conditions, as well as preliminary engineering analyses. Mitigation measures were developed from work with similar project/soil conditions. ' Draft Geologyand Soils Discipline Report 17 May 2004 P P Y Strander Boulevard Extension City of Renton - , .vr l,71 I I 4 Sound Transit 1 I m Property "- €g ru. i - i ! t Vs q l u r � - � I Y , -102 ri__ �� � ,�.- ..- _fix_ �—I- �-`1-_'— �, t`!I,! i .-,.x �• ,``. ....- .. ram.. , t.- "I�•"" PROPOSED�:� r. .r BOULEVARD I,r'` ,,;� 1.,., � I : I t,•— �>i I . I�� '. ^ND � z. � ` -101 MW B+103 1 i i, I: t • su.5 I i n .l' n'.Ile It`I Z `o H:�.{ � ' `1/pr T....-;.,pr-1--_ r '-• ... i •--;i i''4;��';'•t1;;11�i:•t•,_'•;ll i?I I::; -.. 4-.r--��' .. 1 ! Q -._w__ .. -- - - .t -tY+ ��''. X, ;_ \\�\1 t --`� � .,( ,,`\•���\4 �\}!` I P rt i•l.<'+i r�.+� � •r -_.....,, v ' Tukwila K t Clof - t4 _ -- Property `;• n; ,, � TT Ix Cu LL r I1 ri `!'• ''`! ! i jli!�,1�,�` I!, I ii i I I -t--i-... i .y ,� r a) tr :,ID t;:.{,tom i , j.f iCL o LEGEND Current Boring Designation and Location Surveyed by Perteet o B-100 a 9 (Shannon&Wilson,lnc.) 113-200 Current Boring Designation and Approximate LocationI- Q (Shannon&Wilson,Inc.) 0 60 120 ' N Geology and Soils Discipline Report o B-300 Boring Designation and Approximate Location(previous,by others) m NOTES Strander Boulevard Extension N TP-300 Test Pit Designation and Approximate Location(previous,by others) Scale in Feet 1. This figure is based on drawings Renton and Tukwila, Washington 9 Cone Penetration Test Designation and Approximate Location ' — T provided by Perteet via the ' C-300 (previous,by others) ( 1 _ Buzzsaw website:22044EB.dwg, o dated 8-22-03;22044pts.dwg and MW Monitoring Well c 22044ROW.dwg,dated 7-9-03. SITE AND EXPLORATION PLAN VWP Vibrating Wire Piezometer �( - k r 2. Survey performed by Perteet. R J - May 2004 21-1-09369-002 9 A Generalized Subsurface Profile Designation and Approximate Location(See Figure 3) — - 3. Elevation datum is NAVD88. SHANNON& WILSON INC. FIG. 3.1 Sheet Key Plan LL Geotechnical and Environmental Consultants Sheet 1 Of 8 f , , , Boer g Longacres Site Sound Transit .._ I, Property .._ . ',V-1 \:;�:t:i-::f- _^� III,. ..- —T•I } n ---_- -_'_-_. _ - ', _ ---- _ w�u , I ' a r � \ c , t ri PROPOSED STRANDER BOULEVARD B-102 ! ,� -\ - - _ - __ - - - - -.... PROPOSED 11-- i B-104 MW/�fWP r n/WP B-107 ,.,: - B-110 MW B-109 '_.City of Renton Right-of-Way I ` a ✓, q e � i 5-103 - -- ---- - ' - k, -a0 VWIP `43 _ .I r III I� ' �Iry 31�I O - II + f Q . a NSF. City of B-30 o I,,..) s.. '-- _,.........• f I+:.I I ( i I-- `��J 4 i ;I Jf �o i� +�� t 2 ' N Tukwfia Property Q o O d Q { o ` _ �_ -�, „m w s w w ; ' Boeing Longacres Site ti a .. Q i Y- '� I i DE, TREES DE4iE TREES _ i uT Q' 4 � ia.... __.__.....,-_-o 1'tl 44 O rno i o LEGENDw- r Current Boring Designation and Location Surveyed by Perteet ' � B-100 (Shannon&Wilson,lnc.) B-200 Current Boring Designation and Approximate Location t { ' a (Shannon&Wilson, Inc.) 0 60 120 o B-300 Boring Designation and Approximate Location(previous,by others) NOTES Geology and Soils Discipline Report Strander Boulevard Extension =' TP-300 Test Pit Designation and Approximate Location(previous,b others g g Renton and Tukwila, Washington N 9 PP (P Y ) Scale in Feet 1. This figure is based on drawings o Cone Penetration Test Designation and Approximate Location "r 1 " provided by Perteet via the to C-300 0 (previous,by others) } I�I Buzzsaw website:22044EB.dwg, 1 dated 8-22-03;22044pts.dwg and MW Monitoring Well -` t "' _ .r4 _ - 22044ROW.dwg,dated 7-9-03. SITE AND EXPLORATION PLAN VWP Vibrating Wire Piezometer 2. A 9Approximate Survey performed by Perteet. May 2004 21-1-09369-002 o Generalized Subsurface Profile Designation and x 3. Elevation datum is NAVD88. Location(See Figure 3) Sheet Key Plan SHANNON& WILSON, INC. FIG. 3.1 ii Y Geotechnical and Environmental Consultants Sheet 2 of 8 w �l r •� U ' Boeing Longacres Site , ' B-111 - i;'IARD Cif,Of ej�fon _ .� S - i t i �f!w Q - w\` i .- .•'• ; -, Iv � ' �\mil • T t - .t t U .. : , ,:.5 t'.�.•i ,-ram. :a'- L ^"�, u ` �• r 3 ; s .�''..;, \ R \ � ���,•'l:s:�'"4 O /` - ' a•°i r, '\ k• � - ._ a ?@\ a. ` .4 t` �� f ``may ter _ :ry .yam. , ' /'yJ .M1�• '' tte Boeing Longacres Site12 f _ - ' Y', //�; �•.. J-y B.' ?_,`\ Ji .r LL_ _ �? y,:;i^ ='� _.< ./ / _wax_,..,•.�:'� \ -..�. _ .r•''`~ `,^ l i/,.i / - ,t' ice=. .. // /. '�. O L a.r LEGEND B-100 Current Boring Designation and Location Surveyed by Perteet 0 60 120 ' (Shannon&Wilson,lnc.) Geology and Soils Discipline Report oB-200 Current Boring Designation and Approximate Location NOTES Stfander Boulevard Extension N (Shannon&Wilson,Inc.) Scale in Feet 1. This figure is based on drawings Renton and Tukwila, Washington o f ; provided by Perteet via the ' B-300 Boring Designation and Approximate Location(previous,by others) �t ! _i Buzzsaw website:22044EB.dwg, TP-300 Test Pit Designation and Approximate Location(previous, by others) t j dated 8-22-03;22044pts.dwg and 22044ROW.dwg,dated 7-9-03. SITE AND EXPLORATION PLAN m Cone Penetration Test Designation and Approximate Location }'- C-300 O (previous,by others) 2. S _ - _ � T _r I — -�--�------�_-_ i, .___.,__ _ urvey performed by Perteet. May 2004 21-1-09369-002 o` A Generalized Subsurface Profile Designation and Approximate 3. Elevation datum is NAVD88. Location(See Figure 3) Sheet Key Plan SHANNON&WILSON, INC. FIG. 3.'I °' y Geotechnical and Environmental Consurtants LL Sheet 3 of 8 e a A. \` Boeing Longacres Site ' Wetlands yy • i .. _ � >-_ . A' f.-.._ � z. 1 'Sy, l�✓,Y ci ycA.�9 h\\'�_._.._,_,,.,.___ _.._y w s ! - ...... ..:. .: : .. _: i '. ,.;.w ., ,-' .t Lam._._-f"..... ., _—.__—__-• _ — _ - �.- _ ...� r tkAF :Y ............... _:. _.........—._......... "s, - Y 5 7jj ss A •T r? VAR1 R -. , --- _ n „ Q \, n on Wetlands Renton i,. i t U l t _ nt Il Ali ilk L n Go m / Renton Wetlands cb cli o LEGEND IDC ' B-100 Current Boring Designation and Location Surveyed by Perteet 0 60 120(Shannon&Wilson,Inc.) Geology and Soils Discipline Report w B-200 Current Boring Designation and Approximate Location NOTES Strander Boulevard Extension N (Shannon&Wilson,Inc.) Scale in Feet 1. This figure is based on drawings Renton and Tukwila, Washington S Fa ,. _._. ,;,;: provided by Perteet via the d) B-300 Boring Designation and Approximate Location(previous,by others) 1 l i "r � , _•�- Buzzsaw website:22044EB.dwg, c dated 8-22-03;22044pts.dwg and TP-300 Test Pit Designation and Approximate Location(previous,by others) "` SITE AND EXPLORATION PLAN t {'` 22044ROW.dwg,dated 7-9-03. c Cone Penetration Test Designation and Approximate Location ` C-300 O (previous,by others) ♦ € _ _` ._— 2. Survey performed by Perteet. o E : May 2004 21-1-09369-002 A Generalized Subsurface Profile Designation and Approximate -' ----' 3. Elevation datum is NAVD88. Location(See Figure 3) Sheet KeyPlan SHANNON& WILSON, ANC. FIG. 3.1 Geotechnical and Environmental Consultants Sheet 4 of 8 N TP-301 TP-302 B-304 B-305 • Wetlands i _ '� uR' .:1 ..:tea..� r ,� ;:- .y v., L T� �'�,�' r - <C .u'.'a�_• c x..fA..^ 3=�,^�„�::�-.s. ,,.,.�,...,r i - ✓ I I n� s " •,s T /m � y .-_..— _ - x. r' �r i" - :: al _ .. ---__— _ —. a' TJ}—' — — �I ._ —' . .. ...... r `.-,... y�y�h•�-._\\ti — '_�.%•F - sra r- ._.-_•rw^e+.,--r'o-.._-_.vw•i ' --- 11-5 DENSE TREES .TENSE._ - .. __ 9 -_• ...... DENSE' t � DE�S_ RCS\- � ^,NiE. '4EE' fir,,,.•,t ~ti�� `._-' 'l .{ '^•_ Nr- CM DENSE TREES N C Renton Wetlands N O 0) (D 9 O N_ 7 O ro a LEGEND Q Current Boring Designation and Location Surveyed by Perteet 0 60 120 ' o B-100 (Shannon&Wilson,Inc.) Geology and Soils Discipline Report U) 8-200 Current Boring Designation and Approximate Location NOTES Strander Boulevard Extension N (Shannon&Wilson,Inc.) Scale in Feet 1. This figure is based on drawings Renton and Tukwila, Washington q B-300 Boring Designation and Approximate Location(previous,by others) , provided by Perteet via the p Buzzsaw website:22044EB.dwg, I dated 8-22-03;22044 ts.dw and s TP-300 Test Pit Designation and Approximate Location(previous, by others) p g W.dwg,dated 7-9-03.22044R0 SITE AND EXPLORATION PLAN -" �• ' C-300 Cone Penetration Test Designation and Approximate Location(previous,by others) 2. Survey performed by Perteet. - - - A May 2004 21 1 09369 002 Generalized Subsurface Profile Designation and Approximate -- " 3. Elevation datum is NAVD88. LL Location(See Figure 3) Sheet Key Plan SSHtAANNON&WILSON,e0nical and Environmental INC.sultants Fee. 3.1 5 of 8 1 -302 TP-303 N a) N c m p — ConocoPhillips a _ Tank Farm x f' 305 Wetlands I : —ems_-of--_?ram 6.4 6�07 r , -r¢ i� X r n J o .___ .. •�, ,�,- _•__,,.. -4m) ., y ----- _ r 06 - - — :. - -- - 77Y. --i--�...- a r Renton Wetlands 4 DENSE REE_ L_h_ <L- r� �J O O T O O II O I V O 0 O a, LEGEND C B-100 Current Boring Designation and Location Surveyed by Perteet 0 60 120 ' (Shannon&Wilson,Inc.) Geology and Soils Discipline Report Current Boring Designation and Approximate Location NOTES Strander Boulevard Extension w B-200 (Shannon&Wilson,Inc.) Scale in Feet 1. This figure is based on drawings Renton and Tukwila, Washington ,. provided by Perteet via the B-300 Boring Designation and Approximate Location(previous,by others) r Buzzsaw website:22044EB.dwg, co o dated 8-22-03;22044pts.dwg and TP-300 Test Pit Designation and Approximate Location(previous,by others) - 22044ROW.dwg,dated 7-9-03. SITE AND EXPLORATION PLAN m Cone Penetration Test Designation and Approximate Location x4 C-300 (previous,b others) �� --� %`' �' - -� '. 1�^ '..- Y — 2. Survey performed by Perteet. 12 A May 2004 21-1-09369-002 Generalized Subsurface Profile Designation and Approximate s II 3. Elevation datum is NAVD88. Location(See Figure 3) Sheet Key Plan SBHANNO d&VWI�gSO NnsINC. FIG. 3f 8 i� Sheet 6 of 8 � rh ' 7 r'� l� c B-315 TP-304 :�i ConocoPhillips � ' r � >:f f iTank Farm J 1 / a •�:s - s Wetlands Wetlands S j VL L I y �y. a e • �f y '.ts:.t.,e.: • 1 B-311 B-312 B 313. -- . _ ' - --- — - __ ...... - — _ °._._ ....roc .... B 310 B 203 ¢, Y p� — gl _.._. _—..... _ S IN 27TH Street ' . W _ s v _ M - -- z� • 7TH Street i L ,.:.. ...:. '-...,,,,._„_,,,„-•' g�l i'f wh ��.� I / _-_ ,' w:is:r+�c.t+u>.f: . _...... - - - .....— _ — - - - ! S. w. — iQ lQ Yh:.}k:^,.... .. , t.. a ,. --_ •sh'.a`SAR , yi Renton Wetlands - ,E; 4 - co -t_ <r TP-306 e B-317 `L 't'•1 - a Sri' i ' oi o io'X i� CD Co LEGEND Ell i i!n Current Boring Designation and Location Surveyed by Perteet 0 60 120 U B-100 (Shannon&Wilson,lnc.) Geology and Soils Discipline Report w B-200 Current Boring Designation and Approximate Location NOTES Strander Boulevard Extension N (Shannon&Wilson,Inc.) Scale in Feet 1. This figure is based on drawings Renton and Tukwila, Washington o r __ ' provided by Perteet via the ' M B-300 Boring Designation and Approximate Location(previous,by others) i IC Buzzsaw website:22044EB.dwg, and s TP-300 Test Pit Designation and Approximate Location(previous,by others) - dated 8-22-03;22044pts. SITE AND EXPLORATION PLAN _ 22044ROW.dwg,dated 7-9-03. c Cone Penetration Test Designation and Approximate Location C-300 O (previous,by others) -T� - � 2. Survey performed by Perteet. R k May 2004 21-1-09369-002 At Generalized Subsurface Profile Designation and Approximate Elevation um 9 3. Eltion datum is NAVD88. Location(See Figure 3) Sheet Key Plan SHANNON& WILSON, INC. FIG. 3.1 y Geotechnical and Environmental Consultants Sheet 7 of 8 lL iH � gl if I 1 I _ :--305 I LU I if i xi _.._; \ D f 1 i _..._.....—_.._____. ..___...—..._.._. ._ - i ( P / I Y _........ .a..._............. r,-_._.---._.. - — _ — 77 __ __ _ _ I *� o _ _r 14. —... u ..__..._....-_..._._—_=tea... a,,:� — �. ,^�\ _ (t Ji .. . ... .-,,,,,,� .. — I P _ s m I 1-'fTT IiA -4 � - �i 17 it CL I j I iy I 04 o O o i 9 C-301 ); ! I i s co Ji T o = Ili ' i r B-318 if LEGEND LEGEND B-100 Current Boring Designation and Location Surveyed by Perteet 0 60 120 o (Shannon&Wilson,lnc.) Geology and Soils Discipline Report w B-200 Current Boring Designation and Approximate Location NOTES Strander Boulevard Extension N (Shannon&Wilson,Inc.) Scale in Feet 1. This figure is based on drawings Renton and Tukwila, Washington provided by Perteet via the 1 d6 B-300 Boring Designation and Approximate Location(previous,by others) (0 l ` i �_- Buzzsaw website:22044EB.dw g, s TP-300 Test Pit Designation and Approximate Location(previous,by others) — dated 8-22-03;22044pts.dwg and SITE AND EXPLORATION PLAN 22044ROW.dwg,dated 7-9-03. Cone Penetration Test Designation and Approximate Location C-300 O (previous,by others) __ _ 2. Survey performed y erteet. o_ A i. T� i I� ' May 2004 21-1-09369-002 Generalized Subsurface Profile Designation and Approximate I _ =- r----.=!i 3. Elevation datum is NAVD88. t Location(See Figure 3) Sheet Key PlanHANN�ON&VIWI�BSO�nSI�C FIG. 3.1 LL Sheet 8 of 8 DRAFT 3.2.2 Data Sources Existing Subsurface Data Project files and archives from several sources were reviewed to obtain existing geotechnical subsurface information along the proposed Alternatives 1, 2, and 3 alignments. These efforts were concentrated on sources where large amounts of information were already stored and easily accessed. Data, primarily consisting of borings logs but also including cone penetration probes and test pits, was collected from the following sources: • Shannon& Wilson, Inc. • City of Renton • City of Tukwila • Boeing Company The stored files from each source listed above were reviewed, and selected exploration logs were copied. At some of these locations, the data reviewed were of low quality and therefore were not used in the geological studies. Only data that contained sufficient information to locate the explorations and to evaluate the subsurface geology were selected. The approximate locations of the existing explorations are shown on Figure 3.1 (sheets 1 through 8). The locations of the previous explorations were estimated from available plans and should be considered approximate. The approximate elevations of the previous explorations were determined in three ways: (1) by plotting the approximate exploration tlocations on the current site topography, (2) by assuming the log elevations were in terms of the 1988 North American Vertical Datum (NAVD88) based on their date and their correlation with the current topography, and (3)by converting other elevation data to the NAVD88 datum. The previous exploration logs and additional information regarding each exploration are included in Appendix A. Field Explorations An initial field exploration program was performed for the conceptual design phase of the project to supplement the existing information along the proposed alignment. The field exploration program included drilling 17 borings, designated borings B-101 MW to B- ' 112 and B-201 to B-205. Monitoring wells (MW) and/or vibrating wire piezometers (V WP) were installed in 6 of the 17 borings. Five MWs and four VWPs were installed in the vicinity of the proposed underpass/overpass alternatives to characterize local groundwater conditions. The locations of these monitoring points are shown on Figure 3.1 (sheets 1 and 2). From west to east, they include B-101 MW, B-104 MW/VWP, B-105 VWP, B-106 MW/VWP, B- 108 MW/VWP, and B-110 MW. ' Draft Geologyand Soils Discipline Report 26 May 2004 P P Y Strander Boulevard Extension City of Renton ' DRAFT In general, the explorations were located in areas where the underpass/overpass structures are proposed, along the roadway-widening alignment, and where geologic conditions were not documented. The locations of the recent field explorations are shown on Figure 3.1, sheets 1 through 8. Perteet Engineering (Perteet) surveyed the boring locations between West Valley Highway and Oakesdale Avenue SW(the 100-series borings). The boring locations between Oakesdale Avenue SW and East Valley Highway (the 200- series borings)were not surveyed but were measured from existing features and plotted on the site topographic map provided by Perteet. After plotting the approximate locations of the 200-series borings, the boring elevations, in terms of NAVD88, were estimated. The boring logs are presented in Appendix A. 1 Hydrogeologic Field Testing and Groundwater Monitoring Slug tests were performed in the five groundwater MWs to estimate the hydraulic conductivity of the saturated soils near the proposed underpass excavation. The five MWs and four VWPs were read on a monthly basis from August 2003 to February 2004. In addition, groundwater levels were measured continuously in boring B-101 MW for approximately three months and were compared to surface water elevations in the neighboring Green River to assess the possible influence of the river on groundwater levels at the site. MGeologic and Geotechnical Literature Review In addition to the field geologic reconnaissance during Phase 1, available published geologic and geotechnical literature was reviewed for the proposed alternatives. The reviewed literature included the following: • United States Geological Survey (USGS), Geologic Map of the Renton Quadrangle, King County, Washington(Mullineaux 1965) • National Resource Conservation Service Soil Survey for Kin Count (Synder et o Y g Y ( Y al. 1973) • Flood Insurance Rate Map for King County, Washington and Incorporated Areas (FEMA 1995) • Liquefaction Susceptibility for the Renton Quadrangle, Washington, (Palmer et al. 1994) • City of Renton sensitive areas maps (City of Renton 2002) ' • Draft Technical Memorandum, Strander Boulevard/SW 27th Street Corridor Improvements, Phase I Preliminary Geotechnical Information (Shannon& Wilson, Inc., 2001) Draft Geologyand Soils Discipline Report 27 May 2004 P P Strander Boulevard Extension City of Renton I DRAFT re Geotechnical Report for Conceptual Design, Strander Boulevard/SW 27th Street Improvements, Renton and Tukwila, Washington (Shannon& Wilson, Inc., 2004) Geologic Reconnaissance A field geologic reconnaissance of the proposed Build alternatives was performed in April 2001 during Phase 1. The reconnaissance generally extended 200 feet north and south of SW 27th Street and 1,000 feet north and south of the alignment in the vicinity of the railroad tracks to the west and SR 167 to the east. Geologic features such as soil exposures, cuts and fills, standing water, and vegetational clues to geologic conditions were noted by the Shannon& Wilson representative walking the alignment. Pertinent field reconnaissance information, and preliminary geology based on subsurface data and the geologic literature review have been compiled and are shown on Figure 3.2. 3.2.3 Major Assumptions This report is based on the assumption that the subsurface and surficial soil conditions ' encountered in recent and previous soil explorations, observed during the 2001 geologic reconnaissance and presented in the geologic literature listed above, represent the actual conditions at and near the proposed alternatives. No project borings were completed west of the existing railroad tracks; therefore, it is assumed that the subsurface conditions encountered in the project explorations (located east of the UPRR track)would be representative of the affected environment at the western end of Alternative 3. 3.3 Coordination with Agencies and Jurisdictions Available existing subsurface information was compiled from the City of Renton, City of Tukwila, and Boeing. According to WSDOT Environmental Procedures Manual Section 420 Earth (Geology and Soils),there are no interagency agreements specifically related to geology and soils. 3.4 Policies and Approvals ' The references listed in Section 3.2 (Geologic and Geotechnical Literature Review) above were used during this study. According to the WSDOT Environmental Procedures Manual Section 420 Earth(Geology and Soils), the Transportation Commission's Policy Catalog includes no policies specifically referring to geology and soils. r 1 Draft Geologyand Soils Discipline Report 28 May 2004 P Strander Boulevard Extension City of Renton r I i I N - ---- - Qaw ffi t I - Qaw Qaw Qaw 'f\ "./ I 4. Qaw swrt�rN .rae, � x Qlp ._.._--- i —— ---- �: ConccoPhdUps_ 3E / I !l a - __.. Fes, p 'Tan' i ^ „ E Uy Q i _..... - ' 1 I J PROPOSED S7WANDER BOULEVARD J 4, l " j" / 11, Qip i v x --...... ----- / L d A SSWy East Va� Itz�Road �I !� a verua fl _ M �`' 0 400 800 0 O 0) ' Ico n Cale in Feet N a LEGEND Approximate Location of Geologic Type Boundary m a GEOLOGIC EXPLANATION o of ARTIFICIAL FILL. NOTES Geology and Soils Discipline Report `" 1. The geologic boundaries are adpated from Geologic Strander Boulevard Extension N Qaw ALLUVIUM: Sand,silt,and clay deposited by White and Map of the Renton Quadrangle,King County, Renton and Tukwila, Washington g Green Rivers;contains channel gravels and thin peat Washington, 1965 by United States Geological Survey o6 lenses. Mostly clayey silt and fine sand,locally peaty. o ; (Mullineaux, 1965)and from soil borings conducted by o Shannon Wilson during August 2003.Ql LACUST GEOLOGIC MAP p RINE DEPOSITS: Peat;contains minor amounts y of silt and Gay. Mapped where consistently 3 feet or 2. Base map adapted from drawings provided by Perteet thicker. Locally very soft;under load may readily flow via the Buzzsaw website:22044EB.dwg,dated 8-22-03; FIR laterally,or,if confined,may compress to as little as 10 22044pts.dwg and 22044ROW.dwg,dated 7-9-03. May 2004 21-1-09369-002 percent of its original,in-situ volume. SHANNON& WILSON, INC. FIG. 3.2 ii Geotechnical and Environmental consultants DRAFT 4.0 AFFECTED ENVIRONMENT The information collected from the literature and data review, field reconnaissance, and field explorations was used to develop a description of the affected environment. This description includes the general topographic setting, geology, location of critical geologic areas (such as groundwater levels and glacial soil), location of regional faults and other geologic hazards, and other miscellaneous but pertinent geologic data related to the proposed alternatives. The following sections describe each of these issues in more ' detail. The project vertical datum is NAVD88. The site and exploration plan for the build alternatives is presented in Figure 3.1. 4.1 Project Study Area Description and Topographic Setting The proposed project area is situated in a north-south trending alluvial valley near the south end of Lake Washington south of Interstate 1-405 and bounded by West Valley Highway and East Valley Road. The proposed action would cross the UPRR and BNSF railroad tracks and Springbrook Creek, pass through the Boeing Longacres site, and pass by the Renton wetlands, the ConocoPhillips Renton Terminal (tank farm), Sound Transit property, and several office/warehouse buildings within the cities of Tukwila and Renton. The undeveloped areas of the project area are covered with grass, large patches of blackberry vines, and stands of small-to moderate-sized deciduous trees. In developed areas,the proposed alignment is bordered with buildings, sidewalks, lawns, and parking lots. In general, the ground surface along the proposed alignment is relatively flat, ranging from elevation 33 feet at the UPRR railroad tracks to the west to about elevation 17 feet near the intersection of SW 27th Street and East Valley Road to the east. This elevation difference occurs over a distance of about 6,000 feet. The project topography is shown on Figure 3.1. Currently,three railroad tracks cross the proposed alternatives. One track owned by UPRR and two adjacent tracks owned by BNSF are located approximately 400 and 800 ' feet east of the intersection of Strander Boulevard and West Valley Highway, respectively. The Interurban Trail currently crosses the proposed alternative alignment west of the UPRR track. Strander Boulevard currently ends about one block east of West Valley Highway. The Green River is about 500 feet west of the westernmost end of the proposed alignment (the intersection of Strander Boulevard and West Valley Highway). The Green River meanders but generally flows north-south. Springbrook Creek generally flows from south to north at the proposed project area and currently crosses under SW 27th Street between Oakesdale and Lind Avenues SW in a concrete box culvert. Draft Geologyand Soils Discipline Report 30 May 2004 P P Strander Boulevard Extension City of Renton I� DRAFT 4.2 Geologic Conditions b ' The geology and subsurface conditions in the proposed project area were inferred from the material and information obtained from the recent and previous explorations, monitoring wells and V WPs, and from geologic maps of the area. The interpretation of the subsurface conditions for the underpass/overpass alternatives is summarized in the Generalized Subsurface Profile A-A' presented on Figure 4.1, sheets 1 through 3. In this profile, the strata have been delineated according to geologic units. The geologic unit contains soils that are interpreted to have a common origin or process of deposition. Different soil types may be found within each geologic unit; a general soil description associated with each geologic unit is provided on Figure 4.1. The following sections include a description of the site geology and the subsurface soil and groundwater conditions encountered along the project alternatives. 4.3 Project Study Area Geology The proposed alignment is located in the central and eastern portions of a relatively flat alluvial valley confined on the eastern, western, and northern sides by northerly-oriented ridges. The elevations of the ridges range from about 400 to 500 feet. A narrow gap ' between the ridges about 3/4 of a mile wide connects the north end of the valley to the southern end of Lake Washington. ' Two existing rivers and two former river channels have or had an influence on the soils that underlie the proposed alternatives and roadway widenings. The Green River currently flows beneath the existing Strander Boulevard just west of the proposed action. ' The Green River is a meandering channel within a broad valley. It becomes the Duwamish River north of the City of Tukwila. The headwaters of the Green River are in the Mount Rainier area of the central Cascade Range. A former channel of the Green River is documented in a published geologic map; it is shown about 1/2 mile to the east of the present channel,probably in the vicinity of alignment between borings B-I I I and B-112. During the formation of the alluvial floodplain, the channel of the Green River ' moved regularly back and forth across the valley. The Cedar River originates in the central Cascade Range,just north of Stampede Pass. It ' empties into the Puget Lowland at Renton and flows northward into the southern end of Lake Washington. It naturally flowed into the Green/Duwamish River via the Black River prior to 1917. In 1917, as part of the construction of the Lake Washington Ship Canal in Seattle, the waters of Cedar River were diverted in an excavated channel into Lake Washington, leaving the 2-mile-long Black River dry. Therefore, water and sediment from the Cedar River drainage system no longer contributes to the Green/Duwamish River system. In 1962, the construction of the Howard Hanson Dam on the Green River resulted in the control of the Green River water and eliminated the ' sediment supply from the upper part of the Green River drainage basin. These relationships are important to the history and future of deposition in the vicinity of the proposed action. Draft Geologyand Soils Discipline Report 31 May 2004 P P Strander Boulevard Extension City of Renton City of Tukwila PROPOSED LIPRR_ Current BNSF 1 Property RIGHT-OFMAY Right-of-Way B-1..01 MW ;Proj. 14'N.) B"102 B-103 B-104 MW/VWP B:-105 VWP (Proj.29'S.) (Proj.35'N.) (Proj.28'S.) (Proj.31'N.) Existing Ground Surface Hf Hf 15 ? 16 a Ha D(fine grained) 16 14 r2 ? I ? 3 12 12 He D ? 1 "" ,. 2 a D (fine grained) 2 1 14 2 a D(finegrained) +�. ? 11 I i 3 Ha D fine rained 2 I ? I a D(fine grained) I Hp — He D 12 Hp I 11 33 __._..... ... ......... ?. Hp a D(fine grained) + I _.. ?_.. .... 0 .. ... .... _ . ,..� . �., ......... 1 I Hp. He D 19- _.. 8. .... ,... ,.,_. _fn . ? • 122 115 ? i 5 134 ? 15 122 135 27 =37 141 133 156 ; 120 44 44 I 136 128 134 139 I �31 Estimated Altemative 2 Underpass Location 32 Ha D(fine to medium grained) 1 39 1 133 (Rough estimate of underpass location i222003 137 _ 31 with final depth of approximately 25 feet.) 132 _ . —......_.._. _....... =.41. _ 136 T/25f2003 T...24... ......... ......... . ......._ I 1 Ha D(fine to medium grained) 45 M 137 ? 121 ? ? u_ O u_ ti ? 136 2 g 14 N S 15 14 i K W uj,_ -60 _ .... _ .................... .... ._....._ ._..___.... _ .... _ =_a__ .._..._.._.._._....... _.. __._._._......._........._ ----_ _. .. —�' 129 co 01 10 ' I 0 ? Ha C (fine to medium grained) W LL1 M ? W 0 110 0 7/2312003 ? 10 He C ' co 87 W =5016" j 50/4' Z 0 90 _..._ -.___. __ ._.. ._.__ _... 5015-_ _ - .5 _ _ _._ -._-__.— _ Hag U - f —�. - --50/4 a 1 52 170 F- o ? ? ? } 113 ? I He C 157 125 ? a146 130 Ha C(fine to medium grained) I 119 -120 H g i v i `�� -50(5 a - i I =OF Cb IL i 167 N i 0 241 i C ? Cl) 2bd q -150 ___ ..._— __ _ _w.__ _.._ _.__ —. __ ___._.___ ___ _ =50 _. """- � � � Qva(glacially overridden)--���--�-- 5015" o ! 7/24/2003 � i I i3. E i c -180 0 15+00 16+00 Stationing in Feet 17+00 Geology and Soils Discipline Report w Strander Boulevard Extension N Renton and Tukwila, Washington 0 0 10 10 o so so GENERALIZED SUBSURFACE m PROFILE A-A' Scale in Feet o May 2004 21-1-09369-002 Horizontal =Vertical bi SHANNON& WILSON, INC. FIG. 4.1 E r Geotechnical and Environmental Consuftants Sheet 1 of 3 Ar ' City of Renton East Right-of-Way _ 60 3-106 MW/VWP B-107 B-108 MW/VWP B-109 (Prof.9'S.) (Proj.22'S.) (Proj.31'S.) (Proj.30'N.) B-110 MW Existing.Ground Surface .. .. ._.. ...... 30 g8 r5 =2 13 =5 13 ? 16 ? �5 =aMULL ? =3 He D Tf " =0 Hp? =7 ? g 0 a D(fine grained) 16 ., ,� 2 Hp 16 7 ......... _.... .. 2 p g }{p ....._... ... �..... 0 ? =20 124 4 1 = 28 23 133 =z7 _14 _ Estimated Alternative 2 Underpass Location =35 =25 132 =37 Ha D(fine to medium grained) : 130 (Rough estimate of underpass location =43 130 =24 7 33 He D 133 with final depth of approximately 25 feet.) 39 =37 =37 ? ? _ C) 22 21 ? 721 - - j _._. 32 33 .. 7/28/2003 = 8/1/2003 120 a/a/2ao3 -30 W Ha D(fine to medium grained) =27 17 ? 114 g 32 Ha C(fine to medium grained) W 117 132 v co 115 =27 129 ._._ _ _................__...... ..................--... _....................-- ..................._....._..._._. ..................;............._........._............__........._«_ .. . ........_._..._..__.._ _...............---....._........................_.._. -60 0 z Ha C (fine to medium grained) =36 .145 124 154 130 ? N 5016" H b 130 8/1/2003 o Hag 139 .. _...-— ........ ...-- .._.. ..... ..._.. ......... _._._......_._. __. . .. _ z-- 90 o ? ? 1 14 ? He C l 34 3 9 Ha C(fine to medium grained) 44 —?? L t m 50/4" -Ha _......................._..__......................._....._;....._....._....._.................. ......................_ ._........._..............__.._....._..--.._..---..._..._........._._.........__.__.._._..._ _ 9 _............._......__....._...__.................._.....---.._._.—._......._..--- —._.... ---..._ _.............._...._....._..._..—._._......_... _.............._.................._.._ __............._.._.. -...-....— .._..............__.._.........._............_._.._ ............-..............._....................... -120 —50I5• Q o '5015" ii I N 7/3'�/2003 0 o j m i r� i 1 rn i i I O i i 1 .........._ ' __....._. _.._._._...... ...__... _...... - _........ _....... ............. ...................... ... -150 N j : i 1 i. n N i N i Geology and Soils Discipline Report o w 19+00 20+00 21+00 22+00 Strander Boulevard Extension g Stationing in Feet Renton and Tukwila, Washington ' 0 0 30 60 GENERALIZED SUBSURFACE N PROFILE A—A' m Scale in Feet o May 2004 21-1-09369-002 Horizontal =Vertical SHANNON& WILSON, INC. FIG. 4.1 Geotechnical and Environmental consultants Sheet 2 of 3 r r r r rr rr rr rr Ire Ir rr rr rr rl rr rr r� r rr LEGEND B-104 MW/VWP Boring Debi( ,41 ratioo (Proj. 28' S.) — Projected Distance Water Level During Drilling USCS Symbol =26 Standard Penetration Test Blows/Foot Water Level Observed with MW or VWP =50/5" _ Standard Penetration Test Blows/Inches Driven Approximate Underpass Excavation Line � Y p " ' Shelby Tube Sample VWP ? Approximate Geologic Contact _ Well Screen — ? Approximate Contact of Glacially Overridden Soil Bottom of Boring 7/25/2003 _ Date Completed Horizontal Datum = NAD 83-91 Vertical Datum = NAVD88 GEOLOGIC EXPLANATION Hf FILL U) He ESTUARINE/OVERBANK DEPOSITS (Deltaic): Q Clayey SILT and silty CLAY, locally trace to fine sandy, trace organics to peaty o OD DUWAMISH/GREEN RIVER PROVENANCE, where discernible (Mt. Rainier) o © CEDAR RIVER PROVENANCE, where discernible bi oF—Hp-1 PEATY or PEAT 0 Ha ALLUVIUM CHANNEL DEPOSITS: Clean to silty, fine and fine to medium SAND, trace fine organics a� OD DUWAMISH/GREEN RIVER PROVENANCE, where discernible (Mt. Rainier) M © CEDAR RIVER PROVENANCE, where discernible o� NF—H-b-1 BEACH DEPOSIT: GRAVEL or clean to slightly sandy o GRAVEL or gravelly SAND, trace shell fragments o> M o Hag CEDAR RIVER ALLUVIUM: Sandy GRAVEL and gravelly SAND, scattered organics o Qva VASHON ADVANCE OUTWASH: Very dense, gray, LO gravelly SAND tf a a� o! aU c Q NOTES 0 Geology and Soils Discipline Report 1. This profile is generalized and based on interpretations of D field explorations. Variations between conditions depicted Strander Boulevard Extension w 0 on this profile and the actual conditions may exist. Renton and Tukwila, Washington 0 0 2. Elevations and boring locations are based on drawings provided by Perteet via the Buzzsawwebsite: GENERALIZED SUBSURFACE 22044EB.dwg, dated 8-22-03; 22044pts.dwg and PROFILE A-A� 22044ROW.dwg, dated 7-9-03. c 0 May 2004 21-1-09369-002 SHANNON & WILSON, INC. FIG. 4.1 LL Geotechnical and Environmental Consultants Sheet 3 of 3 DRAFT The Puget Lowland was glaciated as many as six times, with the most recent glaciation between about 15,000 and 13,000 years ago in the central part of the lowland. Following deglaciation, a deep (200 to 300 feet below present elevation) embayment extended southward to about present day Auburn. After glacial retreat, rebound of the land, and the global rise of sea level stabilized, an arm of Puget Sound extended southward to the ' vicinity of Auburn. Sediment filled in this embayment slowly by river channel deposition and overbank flooding but more catastrophically by deposition from the Osceola Mudflow from Mount Rainier that occurred about 5,700 years ago. As the delta ' of the Green River built northward, it eventually reached the proposed project area. Complicating the depositional history of the proposed project area is sediment that was deposited by the Cedar River. Sediments that are characteristic of the rocks and glacial materials in their areas of origin make it possible to identify the source of some of the sediments that lie beneath the proposed alignment. Descriptions of the geologic units, including their geologic origin and geotechnical characteristics, encountered at this site are presented in the following subsections. They are presented from oldest to youngest and are largely based on the recent borings. ' 4.3.1 Vashon Advance Outwash (Qva) ' The advance glacial outwash was deposited during the last glaciation of the Puget Lowland and was overridden by about 3,000 feet of glacial ice. This unit consists of very dense, gray, gravelly sand and was only encountered in the bottom of boring B-103. The ' unit is comprised of rounded to subrounded particles of crystalline rock and has a relatively high permeability. ' 4.3.2 Cedar River Alluvium—Gravel (Hag) This very coarse alluvial unit was deposited from the ancient Cedar River after the last glaciation of the Puget Lowland. The unit consists of dense to very dense, sandy gravel and gravelly sand and contains scattered organics. The unit is comprised of rounded to subrounded particles of crystalline rock, typical of glacial deposits in the Cedar River Valley, and has a relatively high permeability. Drilling action indicated that there might be cobbles and boulders in this geologic unit. Two strata of this unit were encountered in the deeper borings (13-103, B-105 VWP and 13-107) separated by other alluvial layers about 15 feet thick. 4.3.3 Duwamish/Green River Alluvium (HaD) This fine-to medium-grained alluvial unit was deposited in the channels of the Green/Duwamish River and was not overridden by glacial ice. The unit consists of ' medium dense to very dense, clean to silty, fine sand and fine to medium sand,with scattered fine organics. It is comprised of subrounded to subangular pieces of dark gray to black basalt and red to red-brown andesite. It has a range of relative permeability from low to high. This alluvial deposit was found in all of the explorations and significantly thickens to the west of B-108 MW/VWP. Draft Geologyand Soils Discipline Report 35 May 2004 P P Strander Boulevard Extension City of Renton ' DRAFT 4.3.4 Beach Hb Deposit P ( ) ' This coarse soil was deposited on beaches or created by wave action on beach lines in the Green/Duwamish River Embayment during a lower level of Puget Sound. The unit ' consists of very dense gravel; clean to slightly silty, sandy gravel or gravelly sand, with a trace of shell fragments. The unit is comprised of rounded to subrounded pieces of crystalline rock but with traces of basalt and red andesite and has a relatively medium to ' high permeability. The presence of shells fragments was confirmed in two borings, B- 109 and B-205. 4.3.5 Cedar River Alluvium (HaQ This fine to medium alluvial unit was deposited from the ancient Cedar River after the last glaciation of the Puget Lowland. The unit consists of loose to very dense, sandy gravel and gravelly sand, and contains scattered organics and numerous lenses and layers of loose silt and fine sand, and is locally clayey. This unit is comprised of rounded to ' subrounded particles of crystalline rock, typical of glacial deposits in the Cedar River valley. This unit has a range of relative permeability from low to high. Based on borings B-107 and B-109,this unit has a maximum thickness of about 50 feet. The unit appears ' to pinch out to the west, as indicated by the soils encountered in borings B-102, B-103, and B-105. To the east of boring B-110 MW,the borings did not penetrate deep enough to encounter Cedar River alluvium. 4.3.6 Estuarine/Overbank Deposits (He) ' The Green/Duwamish and Cedar Rivers deposited this fine-grained floodplain and deltaic unit. This unit was not overridden by glacial ice. It consists of very soft to medium stiff, slightly fine sandy, clayey silt and silty clay, with scattered organics and discrete peat ' lenses and layers. This unit has a relatively low permeability. It is found throughout the site, in every boring drilled along the proposed alignment. ' 4.3.7 Peat/Peaty Deposits (Hp) A peat layer about 1 to 3 feet thick was encountered between about elevation zero and 10 feet in borings B-101 through B-103, B-105 and B-106, B-108 through B-110, and B- 112, which indicates a somewhat continuous peat deposit west of Oakesdale Avenue SW. Logs were encountered in boring B-I I I between 22 and 27 feet below ground surface. A ' more continuous peat layer about 4 to 5 feet thick was encountered near the same elevations in all the borings east of Oakesdale Avenue SW (B-201 through B-205). Draft Geologyand Soils Discipline Report 36 May 2004 P P Strander Boulevard Extension City of Renton DRAFT 4.3.8 Fill H The human-placed fill material consists of varying composition was placed in depressions or for railroad embankments. The permeability of the fill material is ' variable. The largest deposits of fill material are the UPRR and BNSF railroad embankments near the western end of the proposed alignment. ' 4.4 Hydrogeologic Regime The proposed project alignment is located between the Green River and Springbrook 1 Creek within a broad and relatively flat river valley bottom. In general, groundwater readily occurs within the underlying alluvial sediments and is often found near the ground surface, as evidenced by the numerous wetlands in the area. The groundwater ' table elevation near the western end of the project alignment is strongly influenced by the surface water level in the neighboring Green River. Surface water levels within the Green River at this location are influenced by tidal changes in Elliott Bay. Specific ' groundwater conditions are described in the associated Groundwater Discipline Report prepared for this project. ' 4.5 Soil and Groundwater Description Overview 4.5.1 Soil In general, the subsurface soils encountered along the proposed alignment consist of a varying thickness of variable fill (Hf), estuarine/overbank deposits (HeD), and alluvial ' deposits (HaD and Hag). A profile of subsurface conditions along the alternatives is presented on Figure 4.1. The fill material is underlain by about 20 to 30 feet of soft and loose, interbedded estuarine/overbank deposits, fine-grained alluvium. A somewhat continuous peat deposit (Hp) was encountered near the base of the proposed underpass excavation within the estuarine/overbank deposits. This deposit becomes more significant east of Oakesdale Avenue SW. The estuarine/overbank and fine-grained alluvial deposit is underlain west of the BNSF right-of-way by about a 45-foot-thick layer of medium dense to dense, fine-to medium-grained alluvial deposit, which is in turn underlain by a 40-foot-thick layer of soft to medium stiff, estuarine/overbank deposit. Proceeding east of the BNSF right-of-way, the upper estuarine/overbank and fine-grained alluvial deposit is underlain by about an 85-foot-thick layer of medium dense to dense, fine-to medium-grained alluvial deposit. A coarse-grained alluvial deposit was ' encountered in borings B-103, B-105, and B-107 at about 105 feet below ground surface (elevation-85 feet). A glacially overridden deposit (Qva) was encountered below the coarse-grained alluvium in boring B-103 at about 170 feet below ground surface ' (elevation -145 feet). ' Draft Geologyand Soils Discipline Report 37 May 2004 P P Strander Boulevard Extension City of Renton DRAFT 4.5.2 Groundwater rThe groundwater readings during the late summer monitoring period indicate measured groundwater is generally encountered between 11 and 20 feet below existing ground surface (bgs), and at elevations between 9 and 13 feet (NAVD88). During late fall and early winter, measured groundwater levels generally range from 5 to 11 feet bgs and at elevations between 13 and 19 feet. Groundwater levels are likely to rise during the wet ' season (typically from about mid-October through May) when precipitation and river stage levels increase. The monitoring data collected in the fine-to medium-grained alluvium (HaD) at boring B-101 MW indicate diurnal groundwater level fluctuations similar to tidal fluctuations. The data suggest that there is a strong correlation between tidal fluctuations in the Green River and groundwater levels in the HaD unit at boring B-101 MW, and indicate a hydraulic connection between the surface water and groundwater systems. For one 2- week period of recording, surface water level fluctuations in the Green River of ' approximately 5 feet produce groundwater level fluctuations within the HaD unit of approximately 0.3 foot near the western end of the proposed alignment. ' 4.6 Tectonics and Seismicity The study area is located in a moderately active tectonic province that has been subjected ' to numerous earthquakes of low to moderate strength and occasionally to strong shocks during the brief 170-year record in the Pacific Northwest. The tectonics and seismicity of the area are the result of ongoing, oblique subduction along the Cascadia Subduction Zone of the Juan de Fuca Plate beneath the North American Plate. Within the present understanding of the regional tectonic framework and historical seismicity, three broad seismogenic zones have been identified. These include a shallow crustal source zone, a deep subcrustal (intraslab) source zone in the subducted Juan de Fuca Plate, and an interplate or subduction zone. Earthquake sources that have been correlated with historical seismicity include the broad shallow crustal zone(that is, within the continental crust) and the deep, subcrustal zone within the subducted Juan de Fuca Plate. The majority of historical events occurred at ' relatively shallow depths of about 12 miles or less, within the shallow crustal zone. However,the largest historic earthquakes to affect the site include the magnitude (Ms) 7.1 Olympia earthquake of April 13, 1949; the magnitude (mb) 6.5 Seattle-Tacoma ' earthquake of April 29, 1965; and the recent February 28, 2001, magnitude (Mw) 6.8 Nisqually earthquake. All three of these events were located in the subducted Juan de Fuca slab beneath the Lowland at depths of 32 miles and greater. An event similar to these historical earthquakes would create ground motions with approximate characteristics of a 493-year ground motion. Other large historic earthquakes felt in western Washington include the 1872 North Cascades earthquake and two other events in western British Columbia, Canada. The Draft Geologyand Soils Discipline Report 38 May 2004 P P Strander Boulevard Extension City of Renton DRAFT North Cascades earthquake of December 15, 1872, appears to have been one of the largest crustal earthquakes in the Pacific Northwest, with an estimated magnitude of 7+. ' Shallow, crustal seismicity occurs in a diffuse manner within the Puget Lowland. Until recently, seismicity had not been generally correlated with known or inferred structures within the crust, and surface expression of Holocene fault ground surface rupture within the Puget Sound Basin had not been observed. Until the late 1980s, it had generally been accepted that shallow crustal events within Puget Sound Basin would have a maximum magnitude of about 6. However, geologic evidence developed during the 1990s suggests that the geophysical lineament/crustal block boundaries (for example,the Seattle Fault Zone) beneath the Puget Lowland area are seismogenic and capable of producing shallow crustal events of magnitudes up to 7.5. A third seismogenic zone has been postulated near the line of subduction between the Juan de Fuca and North American plates off the coast of the Pacific Northwest. The Cascadia Subduction Zone, as it is called, is presently quiet, with only scattered and diffuse seismicity. No large subduction earthquakes have occurred in this zone during historic times (170 years). Recent geologic evidence suggests, however,that the coastal estuaries have experienced rapid subsidence at various times within the last 2,000 years (Atwater 1987). It is postulated that this subsidence was tectonic and resulted from ' movement along the Cascadia Subduction Zone. While magnitudes, rupture lengths, and recurrence rates have not yet been well defined, work to date suggests that earthquake magnitudes may range from 8 to 9 and may occur at time intervals ranging from 400 to ' 1,000 years. 4.7 Geologic Hazards and Critical Areas ' Alternatives 1, 2, and 3 will be analyzed in accordance with the 1999 Manual for Railway Engineering as outlined by the American Railway Engineering and Maintenance-of-Way Association(AREMA). AREMA defines three seismic performance criteria limit states. The corresponding earthquake ground motion levels and return periods are summarized on Table 4.1. ' Table 4.1: Arema Performance Criteria Limit States Ground Motion Performance Criteria Average Ground Motion Return Level Limit State Period 1 Serviceability 50-100 years 2 Ultimate 200-500 years 3 Survivability 1,000-2,400 years ' In accordance with AREMA criteria,the average return periods corresponding to Ground Motion Levels 1, 2, and 3 are 100 years, 493 years, and 2,120 years, respectively. Based on regional probabilistic ground motion studies conducted by the U.S. Geological Survey ' (USGS), the corresponding peak ground accelerations (PGA) for soft rock conditions at the project site are 0.14g (100 years), 0.32g (493 years), and 0.56g (2,120 years). Based on the conditions encountered in the subsurface explorations,the site would be classified Draft Geologyand Soils Discipline Report 39 May 2004 P P Strander Boulevard Extension City of Renton DRAFT as AREMA Soil Type 4 with a corresponding site factor of 2.0. AREMA describes a Soil Type 4 as a soil profile with 40 feet or more of soft clay or silt with shear wave velocities less than 500 feet per second. The combined thickness of the estuarine (HeD), fine- grained alluvium (HaD), and the somewhat continuous layer of peat (Hp)typically beneath the site is consistent with this criterion. ' Earthquake-induced geologic hazards include landsliding, fault rupture, soft-soil ground amplification, tsunamis/seiches, and liquefaction and its associated effects (reduction of shear strength, loss of bearing capacity, decrease in lateral support, ground oscillation, slumping, settlement, and lateral spreading). The principal earthquake-induced geologic hazard along the proposed alignment is liquefaction and its associated effects. Brief ' descriptions of the other earthquake-induced geologic hazards are also included in the following sections. In addition,the Flood Insurance Rate Map for King County, the National Resource Conservation Service Soil Survey for King County, City of Renton sensitive areas maps, and the Washington Division of Geology and Earth Resources liquefaction susceptibility map were reviewed. The following provides a brief discussion of the principal hazards as well as other critical areas. Figure 4.2 presents the soils map for the proposed project area, and Figure 4.3 presents the approximate flood hazards. 4.7.1 Earthquake-Induced Landsliding ' Because of the flat topography in the proposed project area, the risk of earthquake- induced landsliding is very low. ' 4.7.2 Fault Rupture The potential for fault rupture is low because the southern edge of the Seattle Fault, ' which is an east-west trending structure, is located about 5 miles (8 kilometers) north of the site. 4.7.3 Liquefaction Soil liquefaction is a phenomenon in which pore pressures in loose, saturated, granular soils increase to a level approximately equal to the effective stress during ground shaking; this results in a reduction of shear strength of the soil (a quicksand-like condition). The effects of liquefaction may include a decrease of bearing capacity for ' shallow foundations, reduction in lateral and vertical deep foundation capacities, ground surface settlement, downdrag forces on deep foundations, lateral spreading, and embankment instability or slumping. The Build alternatives cross recent fill and soft and loose Holocene deposits that are susceptible to liquefaction and its associated effects. A conceptual design-level liquefaction potential analysis was performed using soil ' ground motions that correspond to Ground Motion Levels 1, 2, and 3, or the Serviceability, Ultimate, and Survivability Performance Criteria Limit States, ' Draft Geologyand Soils Discipline Report 40 May 2004 P P Strander Boulevard Extension City of Renton ' DRAFT ' respectively. Based on recent research data(Seed et al. 2003), soils with sufficient fines content (fines are either nonplastic or low plasticity with a low plasticity index) are ' considered potentially susceptible to liquefaction. Because the subsurface profile contained continuous layers of low plasticity silt, the liquefaction potential of these layers was also evaluated using Seed's empirical procedure. ' Based on the available subsurface data and the preliminary liquefaction potential analysis for the three deepest borings (B-103, B-105 VWP, and B-107), the depth of potentially ' liquefiable soil was generally the same for the Serviceability, Ultimate, and Survivability cases west of the BNSF right-of-way (approximately). Proceeding east of the BNSF right-of-way (boring B-107), potential liquefaction for the ultimate and survivability ' cases are within about 5 feet of each other. For the serviceability case east of the BNSF right-of-way (boring B-107),there is much less potential for liquefaction. The estimated elevations of potential liquefaction for each of the three AREMA performance criteria limit state are summarized in Table 4.2 below. 1 ' Draft Geologyand Soils Discipline Report 41 May 2004 P P Y Strander Boulevard Extension City of Renton i .......................__.._— ... — '-- Wo FI J it 4a I ; " C Ur 1 tl ! 9 I 1 - r I >v . t s .1 t Wo t Py Ur ! �-sW27TH svge: iz i'—..._ — .-1 --- !' `� � i WO PU SO ConccoPhtltips_- :ir So Tu ` -- -- i ,I _ "--- rl----'-- - -� - j -�Tank Farm ; all: 1 Wo 4 Wo o • i 1 u PROPOSED S7,r�tANDER BOULEVARD .IC: a .. c i 'Al _ t Pu So I Tu [ 1 ..I; , " --- —'— _ i •4 I East Valley Road. . o ! • ,� — Lind Avenue SW I I f �I r I'f fl N I jij'i ti !iiy,I I.: 0 400 800 u_ 0 0 Scale in Feet 9 SOILS EXPLANATION N o Ng NEWBERG SILT LOAM: Well-drained soils formed in alluvium in the stream valleys. LEGEND ' r Wo WOODINVILLE SILT LOAM Approximate Location a : Nearly level and gently undulating,poorly drained soils of Soil Type Boundary formed under grass,in alluvium,and on stream bottoms. d a Ur URBAN LAND: Soil that has been modified by disturbance of natural layers with 0 additions of till material. Geology and Soils Discipline Report fO NOTES Strander Boulevard Extension w Py PUYALLUP FINE SANDY LOAM: Well-drained soils formed in alluvium,under grass, Renton and Tukwila, Washington o hard woods,and conifers. 1. The soil type boundaries are adapted from The Soil 9 ' c Survey of King County Area,Washington, 1973 by So SNOHOMISH SILT LOAM: Poorly drained soils formed in alluvium in stream valleys. United States Department of Agriculture Soil g Conservation Service(Snyder and others,1973). SOILS MAP 7 Pu PUGET SILTY CLAY LOAM: Poorly drained soils formed in alluvium,under grass,in m small depressions of the river valleys. 2. Base map adapted from drawings provided by Perteet ' m via the Buzzsaw website:22044EB.dwg,dated 8-22-03; May 2004 21-1-09369-002 o Tu TUKWILA MUCK: Very poorly drained organic soils fromed in decomposing vegetation. 22044pts.dwg and 22044ROW.dwg,dated 7-9-03. SHANNON&WILSON, INC. FIG. 4.2 ii Geotechnical and Environmental Consultants _... — --- —---._ ...... ; if i r Zone AH 11 { t ., Zone AE I � . =� . ..__ wx Ail _ r — ... . r .: { Zone AE ) ( Zone c,, z Zone ty :•. ,i q u + 1 r!': i >—S 27?H Street Zone X a c3 " — _ 2—_._...--- _ ....----....... —s'� [xis I i ,a.� :{j i.i �-- � ,,�.- -- --•"`` � —-—� - Tank Farm(l R Jr _ - ' 1 Q . ,�, 5! . ;;.;_,-, �-----�_- � � I i' PROPOSED Zone max ; -..�— I�::j / 3TRANDERBCtiLEV.4RDl: . a Zone X t ;� o ��� ; East Yatiey Road o Lind Avenue SW IX N 1 t, If I.. I � E it I I�' i! - •_ ii gal: m tTa LL O O aT Co M O N LEGEND 0 400 800 NOTES a Approximate Location of 1. The flood hazard boundaries are adapted from 3. The entire project alignment falls within a high Flood Hazard Boundary Scale in Feet the Flood Insurance Rate Map for King County, liquefaction hazard area. This conclusion is Washington and Incorporated Areas,Map No. based on conceptual design analyses and the Q 53033C0978F by Federal Emergency map of Liquefaction Susceptibility of the Renton L o FLOOD HAZARD EXPLANATION Management Agency. Quadrangle,Washington by the Washington Geology and Soils Discipline Report U) Division of Geology and Earth Resources(1994). Flood Hazard Areas for 100-Year Flood Strander Boulevard Extension w 2. This map illustrates flooding potential within the o Zone AE Event;Base Flood Elevation is About 20 Springbrook Creek drainage area. Flooding 4. According to the City of Renton sensitive areas Renton and Tukwila, Washington Feet(NAVD88) potential within the Green River is contained Erosion Hazards Map(Palmer and others 1994), ' ° within the dikes that border the river in this the entire project alignment falls within a low o Flood Hazard Areas for 100-Year Flood vicinity. The 100-year flood within the diked erosion hazard zone. HAZARDS MAP Zone AH Event;Flood Depths Could Range from 1 Green River is estimated to be at elevation 28 to 3 Feet feet as described in the report text. 5. Base map adapted from drawings provided by ' Perteet via the Buzzsaw website:22044EB.dwg, May 2004 21-1-09369-002 o Zone X Flood Hazard Areas for 500-Plus-Year dated 8-22-03;22044pts.dwg and Flood Event 22044ROW.dwg,dated 7-9-03. SHANNON& WILSON, INC. FIG. 4.3 LL GeotaOrical and Environmental Consulla;;a ' DRAFT Table 4.2: Estimated Elevations in Feet of Potential Liquefaction by Arema Performance Criteria Limit State Boring --Fserviceability I Ultimate Survivability B-103 -85 -85 -85 B-105 VWP -115 -115 -115 B-107 0 -100 -105 Based on the geologic conditions at the site and similar soil conditions encountered in the borings along the proposed alignment, the depths of potentially liquefiable soils along the SW 27th Street portion of the Build alternatives are anticipated to be similar to the conditions at the proposed underpass/overpass. The Liquefaction Susceptibility Map of the Renton Quadrangle compiled by Palmer, Schasse, and Norman for the Washington Division of Geology and Earth Resources (1994) shows that the entire project area is within a high liquefaction susceptibility zone. The effects of the potentially liquefiable soil beneath the proposed action would likely include reduction of vertical capacity and a reduction in lateral support/increased lateral soil pressures on the proposed foundations and ground settlement. Estimated earthquake- induced ground settlements at the three deepest borings for the three design earthquakes are summarized in Table 4.3 below. Table 4.3: Estimated Liquefaction-Induced Ground Settlement in Inches Earthquake Return Period/Level Boring B-103 Boring B-105 VWP Borin; B-107 100-year 13 to 18 14 to 19 4 to 5 (Serviceability) 493-year(Ultimate) 20 to 28 33 to 45 21 to 29 2,120-year 20 to 28 33 to 45 30 to 41 (Survivability) 4.7.4 Lateral Spreading Lateral spreading movement of gently sloping ground occurs as a result of pore-pressure buildup or liquefaction in the underlying soil deposit. The potential for lateral spreading is low because of the large distance to and relatively shallow depth of the Green River. Draft Geologyand Soils Discipline Report 44 May 2004 P P Y Strander Boulevard Extension City of Renton DRAFT 4.7.5 Tsunamis/Seiches Tsunamis and Seiches are earthquake-generated waves developed in a body of water. A tsunami wave could be generated by permanent ground displacements in a basin that contains a water body. These displacements could be due to permanent ground deformation along the fault rupture or from landsliding. Seiches are standing or oscillating waves developed in a closed body of water as a result of earthquake shaking and could be generated by distant earthquakes. The project area is not along a closed body of water or a basin and would therefore not experience a seiche or tsunami. 4.7.6 Landsliding and Erosion Because of the flat topography at the project site, the risk of landsliding is very low. The Soil Survey of King County map (Snyder et al. 1973) was reviewed to approximate areas that may be susceptible to erosion when disturbed by construction. Soil units are considered to be erosion hazards if they are considered to be "severe" or"very severe" in Table 6 (Woodland Groups, Wood Crops and Factors in Management) of the Soil Survey. Table 4.4 presents the soil units, their geologic unit equivalents, and the level of erosion hazard. Figure 4.2 presents the Soils Map. Table 4.4: Erosion Hazard Units Soil Type Geologic Unit Erosion Hazard Newberg silt loam on slopes HaD/HeD Slight o <2/o Puyallup fine sandy loam on HaD/HeD Slight slopes <2% Puget silty clay loam on slopes HeD Slight <1% Snohomish silt loam on slopes HeD Slight <2% Tukwila muck on slopes <1% HeD Slight Woodinville silt loam on slopes HaD/HeD Slight <2% rFill materials (Hf), also designated as urban land (Ur) in the King County soil survey, should be considered severe to very severe erosion hazards on slopes exceeding 15 percent. For temporarily exposed, unretained cut slopes in native soils, the erosion hazard would likely increase. In addition to the Soil Survey information,the City of Renton sensitive areas map for erosion hazards indicates that the entire proposed project area is within a low erosion hazard area. This is noted on Figure 4.3. Draft Geologyand Soils Discipline Report 45 May 2004 P P Strander Boulevard Extension City of Renton 1 DRAFT 4.7.7 Flooding Given the connection between the Green River stage data and the neighboring groundwater elevation data in boring B-101MW, flooding in the Green River may significantly affect groundwater conditions near the proposed action. The Federal Emergency Management Agency's (FEMA) Flood Insurance Rate Map (No. 53033C0978F, effective 5/16/1995) indicates the 100-year flood elevation for the Green River adjacent to the proposed alignment is approximately 28 feet (NAVD88). Such flooding is projected to stay within the levee that borders the river but may cause an increase in groundwater levels to near the ground surface in the vicinity of the Build alternatives underpass/overpass and roadway widening. This conclusion is based on information gathered through January 2004 and should be considered conceptual. The Hazards Map shown in Figure 4.3 illustrates the approximate areas identified by FEMA that may be subject to flooding during 100-year, 500-year, and greater than 500-year flood events. 5.0 IMPACT ANALYSIS Impacts created by soil and geology issues would be related to the effect of new structures on the existing features in the proposed project area. The types of structures that are anticipated with Alternatives 1, 2, and 3 are an underpass (Alternatives 2 and 3), an elevated vehicular bridge structure (Alternative 1), elevated railroad bridge structures (Alternatives 2 and 3), fill embankments (Alternative 1), and cut slopes (Alternatives 2 and 3). In addition, at-grade roadways and a roadway widening would be constructed for each Build alternative. In general, the impacts of Alternatives 1, 2 and 3 would be comparable because their proposed layout are similar and they are located along generally the same alignment within the project area. Construction activity impacts differ from operational impacts in that the duration of the impact takes place during construction or within a short period of time after construction. Construction impacts do not continue in the long term. No indirect or cumulative geology and soil impacts were identified for the No Action or Build alternatives; only direct impacts were identified. Alternatives 1, 2, and 3 would be designed based on the available subsurface information, additional field explorations completed for final design, existing site conditions, and design and construction procedures and criteria approved for this project. If subsurface jconditions at the site are different from those disclosed during the conceptual design field explorations, or site conditions change during the design and construction period of the project, future impacts to the site could occur. Man of the operational direct impacts described in the following sections could be Y P P g mitigated by following established criteria for proper design and/or standard construction practice. The following impact paragraphs state if the impact that is described could be mitigated by proper design and/or standard construction practice. Draft Geologyand Soils Discipline Report 46 May 2004 P P Y Strander Boulevard Extension City of Renton DRAFT and design studies could be used to plan and design Adequate geotechmcal explorationp g appropriate mitigation of many of the operational impacts discussed. Soil borings and test pits should be performed at appropriate intervals along the proposed alignment in accordance with accepted engineering practices to provide adequate subsurface information for final design studies. In addition, explorations should be performed in the following areas: • Cuts or fills higher than 5 feet • Fills over soft soils • Each bridge pier location The operational impacts listed would be evaluated by an experienced geotechnical engineer who would then provide design recommendations considering the subsurface conditions encountered in the field explorations. These design recommendations would take into account the proposed features included in the project and would provide for adequate mitigation for these impacts unless otherwise directed by the City of Renton. Mitigation for construction-related impacts is based on the existing site information as well as on construction procedures in use when this report was prepared. As presented in the following sections, all construction-related direct impacts presented for the Build alternatives could be mitigated by design and construction procedures. Although some of the construction procedures described are nonstandard,they are not uncommon given current seismic design criteria and earthquake engineering technology. 5.1 No Action Alternative 5.1.1 Direct Impacts Cuts No cuts are proposed under the No Action alternative. Fills No fills are proposed under the No Action alternative. Seismic Considerations ' Over time, design-level earthquakes could occur. If earthquakes of significant magnitude were to occur, there would be a potential for liquefaction in the project area; liquefaction could cause large ground settlements (see Section 4.7.3). Draft Geology and Soils Discipline Report 47 May 2004 G gY P P Y Strander Boulevard Extension City of Renton DRAFT Structure Foundation Construction No structure foundation construction is proposed for the No Action alternative. Relationship Between Topography and Alignment Design No cuts or fills are proposed for the No Action Alternative. i Settlement Potential Seismically induced settlements as described in Section 4.7.3 could occur. In addition, long-term consolidation of soft, loose, and organic soils may occur. Vibrations and Noise Due to Foundation Construction No new foundations would be installed for the No Action alternative. Erosion and Sediment Transport During Construction No erosion or sediment transport impacts are anticipated for the No Action alternative. Construction Haul Routes No haul routes would be used for the No Action alternative. Construction Sundry Sites No sundry sites (pit, waste, etc.) would be used for the No Action alternative. 5.1.2 Indirect Impacts No indirect impacts were identified for the No Action alternative. 5.1.3 Cumulative Impacts No cumulative impacts were identified for the No Action alternative. 5.1.4 Mitigation Measures Cuts No impacts from cuts were identified for the No Action alternative. Fills No impacts from fills were identified for the No Action alternative. Draft Geologyand Soils Discipline Report 48 May 2004 P P Strander Boulevard Extension City of Renton DRAFT Seismic Considerations No seismic mitigation would be performed for the No Action alternative. Structure Foundation Construction No impacts were identified for the No Action Alternative because no new structures would be constructed. Relationship Between Topography and Alignment Design No impacts were identified for the No Action alternative because no cuts or fills are proposed. Settlement Potential No settlement mitigation would be performed for the No Action alternative. Vibrations and Noise Due to Foundation Construction No impacts were identified for the No Action alternative because no new foundations would be installed. Erosion and Sediment Transport No impacts from erosion and sediment transport were identified for the No Action alternative. Construction Haul Routes No construction haul route impacts were identified for the No Action alternative. Construction Sundry Sites No construction sundry site impacts were identified for the No Action alternative. Draft Geologyand Soils Discipline Report 49 May 2004 P P Strander Boulevard Extension City of Renton DRAFT 5.2 Alternative 1: Construction of a Roadway Overpass Cross-Valley Link, Relocation of the Union Pacific Railroad Track, and Modification of SW 27th Street to Five Lanes 5.2.1 Direct Impacts Cuts Any unretained cuts may experience erosion and surface sloughing over the lifetime of the project. The degree of erosion would depend on near-surface soils, weather conditions, potential seismic events and establishment of vegetation, surface drainage, and other causes. In addition, in areas where retaining walls are proposed, the stability of the adjacent ground may be adversely affected if the walls are not properly designed and constructed. Cut slope surface slumps occurring in the future may result in the deposit of material onto the pavement and may damage the proposed underpass. For Alternative 1, unretained cut slopes are anticipated to be minimal. Design and standard construction procedures could mitigate impacts from cuts as described in the mitigation section. Fills Fill may be used along the roadway widening and new at-grade roadways for Alternative 1, as well as for approach fills for the overpass structure. Where space is limited, mechanically stabilized earth walls (MSE walls) could be considered to retain the fills. Currently, it is anticipated that the walls would be a maximum of about 6 to 10 feet tall along the roadway widening or at new at-grade roadways. The upper Holocene deposits are of varying densities and consistencies. The looser, softer, and more organic materials could experience significant settlement from the proposed fill. Settlements on the order of 5 to 10 inches could be anticipated where the proposed fill is about 10 feet high. Roughly 2 inches of settlement may occur within about 20 feet of the MSE wall toe, and 1 inch of settlement may occur about 40 feet away from the wall toe. For lower fill heights, less settlement would be anticipated. The majority of the settlement would occur primarily in the first two to three months after fill construction, but due to the presence of organic layers, settlement would likely continue for several months or years. The height of overpass approach fills may exceed 25 feet. Lightweight fill material could be used for high fill approaches. Because of the lighter weight of the fill material,the subgrade soil could support a higher fill than if standard fill were used. Lightweight fills rthat could be considered include expanded polystyrol (EPS), foamed cement, and other lightweight materials that would be stable over the life of the proposed action. Consideration of 100-year flood levels would be made in design of lightweight fills. If EPS is used as lightweight fill, the wall facing and top cap would require proper design and construction to protect the EPS from exposure to and possible decomposition from gasoline/diesel intrusion. Draft Geologyand Soils Discipline Report 50 May 2004 P P Y Strander Boulevard Extension City of Renton DRAFT Existing utilities that are located within proposed fill areas would be subjected to loading and settlement from the overlying fill. Settlement and some lateral loading may also extend out from the toe of the new MSE walls, resulting in potential settlement or lateral loading of adjacent facilities such as existing roadways, buildings, and utilities. Large lateral or vertical loading and movement could then result in damage to those facilities. The presence of soft soils beneath the proposed fills would also result in lateral movement as the subsurface soil compresses under the weight of the new fill. Lateral movement near the toe of the proposed fill could be as much as one half of the estimated settlement. Existing adjacent utilities or structures could be subjected to lateral loading as a result of this movement. In some areas, the existing, soft, subgrade soils may not have sufficient strength to allow for a stable fill, especially during the short-term construction period. Rotational and bearing capacity failures through the surficial soils and the fill could occur. Over time, the stability of the fill would improve as the soils beneath the fill consolidate and gain strength. Design and standard construction procedures could mitigate this impact. This impact is discussed further in the construction impact section below, because stability during construction would likely be the most critical case. Instability during earthquake loading may also result in fill failure. This type of failure would cause potential damage to pavements located on or near the fill. Seismic Considerations Alternative 1 would cross recent fill and Holocene deposits that are susceptible to liquefaction and its associated effects. The effects of liquefaction may include a decrease of bearing capacity for shallow foundations, reduction in lateral and vertical capacities of deep foundations, ground surface settlements, cut slope instability or slumping, and fill instability. Design could mitigate these seismic impacts. Earthquake-induced ground settlements of the overpass would not be completely mitigated; however,their impact would be taken into account in the design and some maintenance may be required after a design earthquake event. Pavements Inadequate subgrade preparation for proposed at-grade and roadway widening pavements could lead to settlement,potholes, cracks, and other roadway distress. In addition, if the design pavement section is inadequate,the same types of distress could also occur. Frost heave may occur in some areas as well, depending on the weather over the life of the project. Design and standard construction procedures could mitigate these impacts. Elevated Overpass Structure Foundations Because of the depth of loose, soft, and potentially liquefiable soil and anticipated bridge loads, deep, driven pile foundations would be required to support the proposed vehicular Draft Geology and Soils Discipline Report 51 May 2004 Strander Boulevard Extension City of Renton ' DRAFT overpass. These deep foundations would bear in underlying, nonliquefiable, competent soil. The deep foundation design would take into account the current AREMA seismic design criteria and the potential for liquefaction and its effects such as settlement and downdrag. No soil- or geology-related direct impacts are anticipated for the proposed overpass supported on deep foundations. Relationship Between Topography and Alignment Design The cut and fill subsections above address Alternative 1 impacts from cuts and fills. Settlement Potential The cut, fill, and pavement subsections above address settlement potential as an operational impact. Because the subgrade has soft soil to a sufficient depth,the proposed fill heights may not be stable on the existing ground. Failures could occur as the fill is placed and the shear strength of the soil resisting failure is exceeded. This could result in rotational failure through the fill and/or a bearing capacity failure of the entire fill, depending on the subsurface conditions and the fill configuration. In areas where the soft subgrade soils are cohesive, consolidation and strength gain would occur over time as the fill is placed. Therefore, slope failures under the proposed fills would primarily be a short-term, construction impact. In addition, temporary construction dewatering may cause ground settlements that may impact utilities and structures. Dewatering-induced settlements are discussed in the Groundwater Discipline Report prepared for this project. Design and standard construction procedures could mitigate the fill settlement impact. Vibrations and Noise Due to Underpass Construction and Railroad Bridge Structure Foundation Construction Appropriate construction procedures as described below could be used to mitigate vibration and noise impacts. Noise impacts are discussed in the Noise Discipline Report prepared for this project. Because of the depth of loose, soft, and potentially liquefiable soil and anticipated bridge loads, deep foundations may be required to support the proposed overpass. Due to the depth of potentially liquefiable and loose/soft soil, deep foundations would likely consist of driven piles. Pile driving would result in noise and vibration impacts to the site. The vibration caused by driving piles through the site soils could impact nearby railroad tracks and utilities because of settlement. Settlements would depend on the type and density of the subsurface soil where pile driving is occurring as well as the proximity of the railroad tracks and utilities. In general,tracks and utilities within about 20 to 30 feet of pile driving operations may be significantly impacted. Vibration impacts generally diminish as the distance from pile driving increases. Noise from pile driving would most likely just be an annoyance to humans nearby. Draft Geology and Soils Discipline Report 52 May 2004 Strander Boulevard Extension City of Renton r DRAFT tPotential Soil and Groundwater Contamination There is a possibility that construction activities would encounter potentially contaminated soil and groundwater. These issues are discussed in the Hazardous Materials Discipline Report prepared for this project. Erosion and Sediment Transport Construction of the Alternative 1 features would require some land clearing, grubbing, removal of topsoil, and other site preparation work. The areas beneath proposed fills and structures and in cut areas would be cleared and grubbed of all vegetation and debris and stripped of all organic topsoil. The debris resulting from clearing and stripping may be removed from the project area or stockpiled for later re-use in landscaped areas. Topsoil material would not be suitable for reuse as structural fill because of the high organic content. The prepared ground surface would have low erosion potential if exposed during the rainy season or in the presence of surface water; the erosion potential would be high in areas where there are exposed cut or fill slopes. Any areas that are disturbed during construction would be subject to increased erosion if proper control measures are not incorporated into the design. The surface water flow across exposed soil would generate sediment and deposit the sediment in a downslope area. The amount of erosion and sedimentation would depend on the amount of soil exposed and/or disturbed, weather ' conditions and/or groundwater conditions, and the erosion control measures implemented. The surface soil could erode and flow into stormwater drains, into Springbrook Creek, and/or onto adjacent properties or streets. Within construction areas,the tires and tracks of heavy equipment may sink into exposed soft surface soil if no work pad is present. The construction vehicle tires could also carry soil onto roadways (haul routes) when leaving construction areas. Standard construction procedures could be used to mitigate construction erosion and sediment transport impacts. Standard long-term erosion control measures would also be implemented including paving, landscaping, and slope revegetation. Construction Haul Routes Construction haul routes would be determined by the contractor and approved by the cities of Renton and Tukwila. Sediment transport impacts on haul routes were discussed in the previous section. Construction Sundry Sites Construction sundry sites (pit, waste, etc.) would be determined by the contractor and approved by the cities of Renton and Tukwila. Alternative 1 would not require major excavation to construct the overpass. Draft Geology and Soils Discipline Report 53 May 2004 Strander Boulevard Extension City of Renton DRAFT 5.2.2 Indirect Impacts No indirect impacts were identified for Alternative 1. 5.2.3 Cumulative Impacts No indirect impacts were identified for Alternative 1. 5.2.4 Mitigation Measures Cuts Mitigation for the Alternative 1 proposed cuts would consist of performing proper design of temporary shoring and permanent walls or slopes, defining the location and extent of unstable soils, and using proper construction procedures. To mitigate slope instability in retained cut areas, retaining wall design should maintain stability of the cut soils. In areas where unretained cut slopes are proposed,the subsurface deposits would be evaluated so an appropriate slope angle could be determined to maintain stability. In addition, vegetation and drainage could be used to improve stability. Fills Mitigation for fills must consider the estimated settlements, lateral movements, and stability issues related to the presence of soft/loose/organic, near-surface soils at the site. Because settlements may be on the order of several inches near the highest portions of the proposed fills, the fills would be designed and constructed to consider this settlement and related impacts. Potential mitigation measures for settlement include the following: • Preload the fill areas where site availability and time schedules allow. • For retained fills,use walls that could accommodate large settlements such as MSE walls. • Sequence construction so that impacted settlement-sensitive structures are installed after most of the fill settlement has occurred. • Relocate existing utilities that are beneath or near proposed fills if the proposed loads and settlements would cause damage to the utilities. • Use lightweight fill materials where settlements must be minimized and alternative measures are not feasible. • Use geosynthetics (such as geogrids or geotextiles)below and within the fill to help stabilize and reinforce the fills. Draft Geology and Soils Discipline Report 54 May 2004 Strander Boulevard Extension City of Renton DRAFT Should lightweight fill be used to construct the overpass fill approaches, the design should account for anticipated flood levels to prevent buoyancy. In addition, proper design and construction of the wall facing and top cap would be required to protect EPS from exposure to and possible decomposition from gasoline/diesel intrusion. Mitigation measures for lateral movement resulting from fill placement are the same as those presented above for settlement. As settlement is reduced, lateral movement would be reduced correspondingly. Seismic Considerations Alternative 1 features should be designed considering the seismicity of the project area and the project seismic design criteria. Liquefaction-induced settlements and resulting downdrag forces could be mitigated for the overpass by supporting it on deep foundations such as driven piles. Pavements Mitigation for pavements would include proper subgrade preparation and pavement design. All pavement areas should be proof-rolled with a heavy vibratory roller prior to placement of the pavement section. Soft areas would be identified by this process and should be removed and replaced with compacted structural fill. Alternatively, the subgrade could be reinforced with geosynthetics prior to placing pavement subbase materials. In fill areas, mitigation measures as previously discussed for fills should be performed. The upper part of the fills should be well compacted to provide good bearing for the pavement. To mitigate frost heave,the pavement section should also be designed to an appropriate thickness for the climate conditions anticipated along the proposed alignment. The pavement section could also be designed to accommodate inadequate subgrade soils. Elevated Overpass Structure Foundations rNo geology and soil impacts were determined for the overpass structure that would be supported on deep foundations. Relationship Between Topography and Alignment Design The cut and fill mitigations described above in Section 5.2.4, Cuts and Fills, address mitigation of the relationship between topography and alignment design. Settlement Potential The cut, fill, and pavement mitigation sections above address mitigation of operational settlement potential under Alternative 1. The short-term construction stability of the proposed fills could be improved (if necessary)by using staged construction and/or r Draft Geology and Soils Discipline Report 55 May 2004 Strander Boulevard Extension City of Renton DRAFT geotextiles. These methods would improve the short-term stability of the embankments as the underlying cohesive soil consolidates and gains strength over time. Staged construction consists of building the fills in stages, depending on the amount of load the subsurface soil could accommodate at its existing strength. As the strength increases over time as a result of consolidation, additional fill could be placed on the strengthened subgrade while maintaining a similar factor-of-safety against failure. Monitoring of the settlement and pore pressure buildup and dissipation would be performed using instrumentation to determine the appropriate staging. Geotextiles could be used to reinforce potential failure zones within the fill. For example, several layers of geotextile could be placed at the base of the proposed fill. A higher staged fill could be constructed on the reinforced base than a fill without geotextiles. Although staged construction may still be necessary to construct the entire fill, using geotextile reinforcements could reduce the number of stages required or could allow for single-stage construction. Lightweight fill material could be used in areas where staged construction is not feasible. Because of the lighter weight of the fill material, the subgrade soil could support a higher depth of fill than if standard fill were used. Lightweight fills that could be considered include expanded polystyrol (EPS), foamed cement, and other lightweight materials that would be stable over the life of the proposed action. Consideration of flood levels would be made in design of lightweight fills. Measures to mitigate settlement resulting from temporary dewatering and/or long-term drainage are described in the Groundwater Discipline Report prepared for this project. Vibrations and Noise Due to Overpass Foundation Construction Driven piles may be used to support elevated structures. To mitigate noise and vibration during driven pile installation, low vibration/noise pile driving equipment could be selected. Alternatively,the steel pipe piles could be driven open-ended or could be driven into a predrilled hole, which would result in lower vibrations. Preconstruction surveys of existing structures and vibration monitoring during pile driving would be required to monitor and mitigate potential damage to adjacent sensitive structures. Mitigation for noise from pile driving is discussed further in the Noise Discipline Report prepared for this project. Erosion and Sediment Transport Construction best management practices (BMPs), such as construction staging barrier berms, filter fabric fences, temporary sediment detention basins, and use of slope coverings to contain sediment onsite, would be effective in protecting water resources and reducing erosion from areas with cuts, fills, and/or excavations. Erosion control measures suitable to the construction site conditions would be included as part of the Draft Geology and Soils Discipline Report 56 May 2004 Strander Boulevard Extension City of Renton DRAFT tproposed action design. Temporary erosion and sediment control plans would be prepared for approval in accordance with 13MPs used by the cities of Renton and Tukwila. Erosion control measures would include vegetative and structural controls. Other controls that could be implemented include restricting slope work activities to the dry season and limiting access to the site. Vegetative methods would include covering cleared or graded areas and excavation or fill approach slopes with jute or other netting as well as mulching or hydroseeding, as appropriate,to minimize erosion and encourage revegetation. Vegetation buffers would be maintained between construction areas and Springbrook Creek to filter out sediments. Structural controls consist of artificial means of preventing sediment from leaving the construction area. Parking and staging areas for vehicles and equipment could be covered with a gravel work pad where appropriate to prevent the disturbance and erosion of the underlying soil. Silt fences would be placed around disturbed areas to filter sediment from unconcentrated surface water runoff. Straw bales would be placed in paths of concentrated runoff to filter sediment. Temporary ditches,berms, and sedimentation ponds would be constructed to collect drainage. Cleaning tires and tracks on heavy equipment before they leave the construction site would also assist in retaining sediment on site. In addition,truckloads should be covered to mitigate sediment deposit onto roadways. Proposed mitigation measures would comply with stormwater design and treatment procedures based on the current City of Renton and City of Tukwila requirements. The erosion and sediment control measures would be in place before any clearing, grading, or construction. 5.3 Alternative 2: Construction of a Roadway Underpass Cross-Valley Link, Relocation of the Union Pacific Railroad Track, and Modification of SW 27th Street to Five Lanes 5.3.1 Direct Impacts Cuts tUnretained cuts for Alternative 2 are anticipated to be less than 5 feet in height, and the underpass depth is anticipated to be a maximum of about 25 feet to design grade. The existing groundwater level is located above the base of the proposed excavation; ' therefore, drainage and uplift issues or base stability issues would need to be addressed during the lifetime of the project. Design and proper construction procedures would ' provide for the adequate operation of the underpass over the long term. The cut impacts to geology and soils for Alternative 2 would be the same as for Alternative 1. Draft Geology and Soils Discipline Report 57 May 2004 Strander Boulevard Extension City of Renton ' DRAFT Fills Fill may be used along the roadway widening and new at-grade roadways for Alternative 2. Where space is limited, MSE walls could be considered to retain the fills. Currently, it is anticipated that walls along the roadway widening or new at-grade roadways would be a maximum of about 6 to 10 feet tall. The fill impacts to geology and soils for Alternative 2 would be the same as for Alternative 1. Seismic Considerations The seismic impacts to geology and soils for Alternative 2 would be the same as for Alternative 1. Pavements The pavement impacts to geology and soils for Alternative 2 would be the same as for Alternative 1. Elevated Railroad Bridge Structure Foundations Because of the depth of loose, soft, and potentially liquefiable soil, anticipated bridge loads, and the railroads' movement/settlement requirements, deep foundations may be required to support the proposed railroad bridges. These deep foundations would bear in underlying, nonliquefiable, competent soil. The deep foundation design would take into account the current AREMA seismic design criteria and the potential for liquefaction and its effects such as settlement and downdrag. No soil- or geology-related direct impacts are anticipated for the proposed railroad bridges that are supported on deep foundations. If the railroads' movement/settlement requirements allow, the railroad bridge structures could be founded on secant pile walls that are tied into the underpass bottom seal. Following a design-level earthquake, the roadway underpass and bridge structures would likely experience liquefaction-induced settlements. The anticipated underpass and bridge settlements would be of a lower magnitude than the surrounding ground surface settlements because underpass construction would have removed (the excavation) or improved(the bottom seal) many feet of potentially liquefiable soil. The railroad track approaches would likely require grading to make the bridge accessible to trains. Relationship Between Topography and Alignment Design Cut volumes are anticipated to be on the order of 45,600 cubic yards for Alternative 2, while roadway widening and at-grade roadway fill volumes may be on the order of 2,900 cubic yards. The impacts to geology and soils for Alternative 2 would be the same as for Alternative 1. Draft Geology and Soils Discipline Report 58 May 2004 Strander Boulevard Extension City of Renton DRAFT Settlement Potential The settlement potential impacts to geology and soils for Alternative 2 would be the same as for Alternative 1. Vibrations and Noise Due to Underpass Construction and Railraod Bridge Foundation Construction Appropriate construction procedures as described below could be used to mitigate vibration and noise impacts. Noise impacts are discussed in the Noise Discipline Report prepared for this project. Because of the depth of loose, soft, and potentially liquefiable soil, anticipated bridge loads, and the railroads' movement/settlement requirements, deep foundations may be required to support the proposed railroad bridges. Due to the depth of potentially liquefiable and loose/soft soil, deep foundations may consist of driven piles or deep slurry walls (discussed later in this section). In addition, deep driven piles may be used to support permanent concrete underpass sidewalls, and/or to provide uplift resistance for the underpass base slab/bottom seal. Pile driving would result in noise and vibration impacts to the site. The vibration caused by driving piles through the site soils could impact nearby railroad tracks and utilities because of settlement. Settlements would depend on the type and density of the subsurface soil where pile driving is occurring as ' well as the proximity of the railroad tracks and utilities. In general,tracks and utilities within about 20 to 30 feet of pile driving operations may be significantly impacted. Vibration impacts generally diminish as the distance from pile driving increases. Noise from pile driving would most likely just be an annoyance to humans nearby. Secant piles,which are overlapping drilled shafts with reinforcement installed in every other shaft, may be used as underpass sidewalls. Secant pile walls would be installed in conjunction with a bottom seal; the secant piles would likely be founded within the bottom seal thus creating an underpass "boat." Following a design-level earthquake, the underpass "boat" would likely experience liquefaction-induced settlements; if the railroads' movement/settlement requirements allow,the secant pile walls could be used as railroad bridge supports. Secant piles could be installed with equipment that does not cause significant vibrations. Because of the depth of loose, soft soil and the high groundwater table at the site, open hole excavation methods would be difficult. Caving ' or sloughing soil within the open hole excavation could impact adjacent railroad tracks and buried utilities. Bottom heave within the secant pile excavation could also occur. Typically, secant pile installations do not cause excessive noise. ' Steel sheetpiling with internal bracing (as needed) could be used as temporary shoring for construction of the underpass sidewalls. Given the loose/soft near subsurface soil conditions, it may be possible to push in and pull out the sheetpiling using hydraulic equipment. Otherwise, a vibratory hammer would be used to install and remove the sheetpiling. The installation and removal of sheet piles could cause undesirable Draft Geology and Soils Discipline Report 59 May 2004 Strander Boulevard Extension City of Renton DRAFT settlements in the vicinity of the underpass excavation, especially if a vibratory hammer is used for installation and removal. In general, the magnitude of the settlements would depend primarily on the relative density of the estuarine/overbank and alluvial deposits and the intensity of the vibration resulting from the driving and extracting operations. Structures located more than 50 feet away from the sheet pile installation/removal operations would be less susceptible to vibration-induced settlements. Typically, sheetpiling installation does not cause excessive noise. Soldier piles and lagging with internal bracing (as needed) could also be used as temporary shoring for construction of the underpass sidewalls. Soldier piles are drilled and installed similar to secant piles, as described above. This temporary shoring method would require dewatering prior to and during construction. Overlapping cement deep soil mix (CDSM)techniques may be used to create an ' underpass bottom seal to resist uplift pressures. If the railroad bridges were to be supported separately from the underpass (on driven piles), the underpass sidewalls could also be constructed of reinforced CDSM. Reinforcement such as H-piles are pushed into the CDSM before it hardens. CDSM is a process to treat soil in situ to improve its strength and to decrease its compressibility and permeability. CDSM involves a series of one to four hydraulically driven mixing augers, 18 to 36 inches in diameter, attached to crane-supported leads. As penetration occurs, cement, bentonite, lime, or other stabilizing slurry is injected into the soil through the hollow stem of the augers. The auger flights penetrate and break loose the soil and lift it to the mixing paddles,which blend the soil and slurry. As the augers continue to advance, additional paddles remix the soil and slurry. Because the augers are not continuous up to the ground surface, the CDSM process does not produce significant spoils at the ground surface. The mixing ' process is repeated, overlapping the previous passes. The overlap is more easily achieved with a multiple auger rig resulting in more uniform CDSM. The CDSM process typically does not produce significant vibrations and noise. As an alternative ground improvement method to CDSM,jet grouting could be used to create an underpass bottom seal. Jet grouting is a ground modification method used to create in situ, cemented formations of soil. The jet grouting technique is used to erode in situ soil and simultaneously mix it with cement grout to form soilcrete. Because much of the upper soils are relatively loose and soft, they would likely be eroded during ' grouting and would result in more grout replacement instead of a soilcrete mixture. The medium dense alluvial sand would tend to stay in place and get mixed with the grout. Jet ' grouting tends to have more spoils at the ground surface because soft/loose soils are removed and replaced with grout. Jet grouting is a bottom-up procedure. An approximately 67inch-diameter hole is drilled to the design depth. Grouting rods are then lowered into the drilled hole, and grout is pumped at high pressure through the rods and out of a horizontal nozzle near the bottom of the rods. Air or air and water could also be pumped with the grout (through separate nozzles)to increase the erosion efficiency of the grout. As soil removal and replacement with grout continues, the rods are rotated and slowly lifted to create a soilcrete column. If only grout is used, soilcrete column diameters of 2 to 4 feet could be achieved. If grout with air and water is used, soilcrete Draft Geology and Soils Discipline Report 60 May 2004 Strander Boulevard Extension City of Renton DRAFT columns with diameters from 3 to more than 4.5 feet could be achieved. Designed integration (overlap) of adjacent columns creates a soilcrete mass. The required thickness of the mass is dependent upon the soilcrete unit weight, permeability, and the hydrostatic uplift pressure at the bottom of the soilcrete. The jet grouting process typically does not produce significant vibrations and noise. ' Slurry(diaphragm)walls could be used for multiple purposes such as railroad bridge support, underpass sidewalls, and tiedowns for uplift resistance when used in conjunction with a tremie seal. Slurry walls are constructed by first installing two slurry guide walls, one on either side of the proposed wall alignment. The guide walls are about 5 feet deep and are spaced a distance a bit wider than the proposed wall width. A linear trench between the guide walls is excavated using one or more equipment passes. As the trench is excavated, mineral or polymer slurry is introduced into the excavation. Next a reinforcing cage, or a steel W or HP section, is inserted into the excavation. Finally, the ' concrete is tremied into the excavation displacing the slurry. The slurry is reconditioned and reused. A steel tube is often introduced at the end of the panel to make a connection with the adjacent panel, depending on the panel-to-panel connection and construction equipment. The joints between panels can be made watertight by means of water stops across joints, or by post-grouting through tubes attached to the reinforcing cage. Slurry walls can be constructed in widths up to about 5 feet. A practical minimum width is about 18 inches. The panel length is determined based on a number of factors, including face stability, concrete, size of reinforcing cage, location of bracing, and the type of excavating equipment. A panel cannot be shorter, or narrower, than one equipment pass. ' Minimum panel length is about 4 to 8 feet depending on the contractor's equipment. A top strut(internal bracing) may be required within the underpass excavation. The slurry wall installation process typically does not produce significant vibrations and noise. ' In lieu of tying down a relatively thin concrete tremie seal with driven piles or slurry walls, or using a thick bottom seal constructed of CDSM or jet grouting, a thick concrete tremie seal could be constructed to resist uplift pressure at the base of the thick tremie seal; however, a thick tremie seal would require a much deeper excavation. Tremie seal installation typically does not produce significant vibrations and noise. Potential Soil and Groundwater Contamination The potential contamination impacts to geology and soils as well as groundwater for Alternative 2 would be the same as for Alternative 1. ' Erosion and Sediment Transport ' The erosion and sediment transport impacts to geology and soils for Alternative 2 would be the same as for Alternative 1. Soils i Report 61 May Draft Geology and So s Discipline Repo y 2004 Strander Boulevard Extension City of Renton DRAFT Construction Haul Routes The construction haul route impacts to geology and soils for Alternative 2 would be the same as for Alternative 1. ' Construction Sundry Sites ' Construction sundry sites (pit, waste, etc.) will be determined by the contractor and approved by the City of Renton and the City of Tukwila. Alternative 2 would require major excavation to construct the underpass. Due to the consistency of the soils that are ' anticipated within the underpass excavation, it is anticipated that the excavated materials would be hauled offsite for disposal. ' 5.3.2 Indirect Impacts No indirect impacts to geology and soils were identified for Alternative 2. 5.3.3 Cumulative Impacts No indirect impacts to geology and soils were identified for Alternative 2. 5.3.4 Mitigation Measures Cuts Mitigation for the Alternative 2 proposed cuts would consist of performing proper design of the temporary shoring and permanent walls or slopes, defining the location and extent of unstable soils, and using proper construction procedures. To mitigate slope instability in retained cut areas, retaining wall design should maintain stability of the cut soils. Based on the soil types present at the proposed project site, these walls would likely ' consist of temporary soldier piles or sheetpiling with a permanent concrete wall, diaphragm(slurry) walls, secant piles, or reinforced CDSM walls. Cross bracing may be used in some areas to improve stability by providing additional lateral resistance to the ' earth pressures behind the wall; this would likely be required in the relatively deep underpass sections. The base of the wall would extend a sufficient depth into undisturbed soils so that adequate passive resistance in front of the wall is generated to resist the lateral earth pressures behind the wall. Underpass sidewall instability may be an impact. If unexpected increased water pressure or additional loading from adjacent ground ' occurs, the underpass walls may become unstable and lateral movement of the wall or settlement adjacent to the wall could occur. ' The design of the underpass sidewalls should consider the soil, surcharge, and groundwater conditions as well as any settlement and lateral movement limitations. The design should consider the worst-case soil, surcharge, and groundwater conditions at each Draft Geology and Soils Discipline Report 62 May 2004 Strander Boulevard Extension City of Renton ' DRAFT ' location along the underpass, as estimated from the final design field explorations. Potential future loading conditions should also be considered in the design. Design and proper construction procedures would mitigate groundwater uplift pressures. The base slab/bottom seal should be designed for the calculated uplift pressures plus an adequate factor of safety. It is anticipated that the uplift resistance could consist of a relatively thin concrete tremie in combination with deep, driven pile foundations or deep slurry walls for uplift resistance, a CDSM or jet grouted bottom seal, or a thick concrete ' tremie seal. In areas where unretained cut slopes are proposed, the subsurface deposits would be evaluated so an appropriate slope angle could be determined to maintain stability. In addition, vegetation and drainage could be used to improve stability. For cut slopes that would occur above the underpass pavement, catchment walls can be constructed. These ' catchment walls would extend above the edge of pavement/sidewalks and serve as temporary retention measures for soil and debris (such as vegetation)that may slide down the slopes from instabilities occurring on the cut slopes. If a slide occurs, the soils that are retained by the catchment walls should be removed after the event. Fills The fill mitigation measures for Alternative 2 would be the same as for Alternative 1. Seismic Considerations ' Alternative 2 features should be designed considering the seismicity of the site and the project seismic design criteria. Liquefaction-induced settlements could be partially mitigated for the underpass by using a ground improvement bottom seal. Liquefaction- induced settlements and resulting downdrag could be mitigated for the railroad bridge structures by supporting the structures on deep foundations such as driven piles or slurry walls. Catchment areas or small catchment walls could be constructed at the base of cut ' slopes or behind retaining walls to minimize sediment deposit onto the roadway after a seismic event. ' Pavements The pavement mitigation measures for Alternative 2 would be the same as for Alternative 1. ' Elevated Railroad Bridge Structure Foundations No geology and soil impacts were determined for the elevated railroad bridge structures that would be supported on deep foundations. As described in Section 5.3.1, Elevated Railroad Bridge Structure Foundations, if the bridges were supported on secant pile walls that are integral to the underpass structure, track approach grading would likely be Draft Geology and Soils Discipline Report 63 May 2004 ' Strander Boulevard Extension City of Renton DRAFT ' required following a design-level earthquake to make the railroad bridges accessible to trains. ' Relationship Between Topography and Alignment Design ' The mitigation measures for Alternative 2 would be the same as for Alternative 1. Settlement Potential The settlement potential mitigation measures for Alternative 2 would be the same as for Alternative 1. Vibrations and Noise Due to Underpass Construction and Railroad Bridge Foundation Construction Driven piles may be used to support elevated structures. To mitigate noise and vibration during driven pile installation, low vibration/noise pile driving equipment could be selected. Alternatively,the steel pipe piles could be driven open-ended or could be driven into a predrilled hole, which would result in lower vibrations. Preconstruction surveys of existing structures and vibration monitoring during pile driving would be required to monitor and mitigate potential damage to adjacent sensitive structures. Mitigation for noise from pile driving is discussed further in the Noise Discipline Report prepared for this project. Secant piles also may be used as underpass sidewalls and to support elevated structures. To mitigate vibrations, low vibration equipment(such as an oscillator system) could be selected. To mitigate potential caving of the soil in the excavated holes, casing would be used in the upper soft/loose soil. Water or slurry inside the casing could mitigate potential bottom heave that could be caused by the high groundwater table. Immediately following secant pile installation, the casing would be removed. To mitigate vibration impacts from sheetpile installation and removal using a vibratory ' hammer,the contractor could experiment with the hammer selected to evaluate its influence on adjacent ground settlements. If undesirable settlements occur, another type ' of hammer with less impact on ground settlement should be used. The sensitivity or tolerance to settlement of any particular buried utility and railroad tracks adjacent to the excavation should be evaluated on a case-by-case basis. iSoldier pile installation mitigation measures would be the same as for secant piles (described above). Erosion and Sediment Transport ' The erosion and sediment transport mitigation measures for Alternative 2 would be the same as for Alternative 1. Draft Geology and Soils Discipline Report 64 May 2004 Strander Boulevard Extension City of Renton DRAFT w Underpass Cross-Valle Link Union 5.4 Alternative 3: Construction of a Roadway U rp s y , Pacific Railroad Tracks Not Relocated, and Modification of SW 27th Street to Five Lanes 5.4.1 Direct Impacts Cuts ' The cut slope impacts to geology and soils for Alternative 3 would be the same as for Alternative 2. The underpass depth is anticipated to be a maximum of about 25 feet at the design grade. Fills The fill impacts to geology and soils for Alternative 3 would be the same as for Alternative 2. The maximum fill wall heights are anticipated to be about 6 to 10 feet ' along the roadway widening. Seismic Considerations The seismic impacts to geology and soils for Alternative 3 would be the same as for Alternative 2. ' Pavements ' The pavement impacts to geology and soils for Alternative 3 would be the same as for Alternative 2. ' Elevated Railroad Bridge Structure Foundations The elevated railroad bridge structure foundation impacts to geology and soils for ' Alternative 3 would be the same as for Alternative 2. Relationship Between Topography and Alignment Design The cut and fill discussions address impacts from cuts and fills. Cut volumes are ' anticipated to be on the order of 66,230 cubic yards for Alternative 3, while roadway widening and at-grade roadway fill volumes may be on the order of 400 cubic yards. ' Settlement Potential The potential settlement impacts to geology and soils for Alternative 3 would be the same ' as for Alternative 2. Draft Geology and Soils Discipline Report 65 May 2004 Strander Boulevard Extension City of Renton DRAFT Vibrations and Noise Due to Underpass Construction and Railroad Bridge Foundation Construction The vibrations and noise impacts to geology and soils for Alternative 3 would be the same as for Alternative 2. Potential Soil and Groundwater Contamination ' The potential soil and groundwater contamination impacts to geology and soils for Alternative 3 would be the same as for Alternative 2. Erosion and Sediment Transport The erosion and sediment transport impacts to geology and soils for Alternative 3 would ' be the same as for Alternative 2. Construction Haul Routes The construction haul route impacts to geology and soils for Alternative 3 would be the same as for Alternative 2. Construction Sundry Sites ' The construction sundry site (pit, waste, etc.) impacts to geology and soils for Alternative 3 would be the same as for Alternative 2. 5.4.2 Indirect Impacts No indirect impacts were identified for Alternative 3. 5.4.3 Cumulative Impacts ' No cumulative impacts were identified for Alternative 3. 5.2.4 Mitigation Measures ' Cuts ' The cut mitigation measures for Alternative 3 would be the same as for Alternative 2. Fills The fill mitigation measures for Alternative 3 would be the same as for Alternative 2. Draft Geology and Soils Discipline Report 66 May 2004 Strander Boulevard Extension City of Renton ' DRAFT 1 Seismic Considerations ' The seismic consideration mitigation measures for Alternative 3 would be the same as for Alternative 2. Pavements The pavement mitigation measures for Alternative 3 would be the same as for Alternative 2. ' Elevated Railroad Bridge Structure Foundations The elevated railroad bridge structure foundation mitigation measures for Alternative 3 ' would be the same as for Alternative 2. Relationship Between Topography and Alignment Design The cut and fill mitigations address mitigation of the relationship between topography and alignment design. Settlement Potential ' The potential settlement mitigation measures for Alternative 3 would be the same as for Alternative 2. Vibrations and Noise Due to Underpass Construction and Railroad Bridge Foundation Construction ' The vibration and noise mitigation measures for Alternative 3 would be the same as for Alternative 2. ' Erosion and Sediment Transport The erosion and sediment transport mitigation measures for Alternative 3 would be the ' same as for Alternative 2. ' 6.0 COMPARISON OF ALTERNATIVES Soil- and geology-related operational and construction impacts and recommended ' mitigation measures were developed based on the proposed project area geology, known subsurface conditions, and the No Action and Build alternatives. Nearly all of the impacts could be mitigated by proper design and standard construction procedures. Liquefaction and, in particular, liquefaction-induced settlement may require nonstandard construction procedures to partially mitigate; however,these procedures, although Draft Geology and Soils Discipline Report 67 May 2004 Strander Boulevard Extension City of Renton ' DRAFT ' nonstandard, are not uncommon given current seismic design criteria and earthquake engineering technology. ' If a design-level earthquake occurred that resulted in liquefaction, the ground surface for all project alternatives would likely experience large settlement. Deep foundations could be used to mitigate the impact of liquefaction-induced settlement and downdrag for either underpass or the overpass elevated structures. Underpass railroad bridges could be supported by secant pile walls that are integral to the underpass. Although the ' underpass/bridge stricture would likely experience settlement following a design-level earthquake, the surrounding ground surface would likely settle more than the underpass/bridge. Alternatives 2 and 3 would be constructed as an underpass below the groundwater level. This would require construction of a tremie or bottom seal to resist uplift pressures as ' well as temporary and/or permanent sidewalls to resist lateral pressures. Temporary groundwater control would be required for construction of an underpass if a tremie option is used. Alternative 1 would be constructed above grade and would not require a tremie/bottom seal, sidewalls, or temporary and/or permanent groundwater control. Table 6.1: Summary of Potential Impacts to Geology and Soils Alternative Direct Impacts Indirect Cumulative' Im acts Impacts No Action Current design-level earthquakes could None Identified. None ' occur and cause liquefaction. The effects Identified. of liquefaction may include loss of bearing capacity for existing shallow foundations, ' ground surface settlement, and lateral deflection of existing utilities. Liquefaction alone could cause excessive ground ' settlement. Alternative 1: Fill settlement, instability, and lateral None Identified. None Construction of a movement could impact underlying utilities Identified. Roadway or adjacent structures as well as walls or Overpass Cross- pavements constructed on the fill. ' Valley Link, Inadequate design of lightweight fill could Relocation of the result in fill buoyancy or decomposition due Union Pacific to the 100-year flood and possible t Railroad Track, gasoline/diesel intrusion. and Modification of SW 27th t Street to Five Lanes Draft Geology and Soils Discipline Report 68 May 2004 Strander Boulevard Extension City of Renton ' DRAFT Current design-level earthquakes could None Identified. None occur during the life of the project, causing Identified. liquefaction. The effects of liquefaction may include decrease of bearing capacity for existing shallow foundations, ground surface settlement, reduction in lateral and vertical capacity of new deep foundations, cut slope and fill instability, and lateral deflection of existing utilities. Liquefaction alone could cause large ground settlement. Poor subgrade preparation and/or design None Identified. None for proposed pavements could lead to Identified. settlement, potholes, cracks, and other roadway distress. Driving new pile foundations may cause None Identified. None vibration-induced ground settlements. Identified. Erosion of exposed cut or fill slopes could None Identified. None cause increased sediment transport onto Identified. other areas of the project, into stormwater drains, and into Springbrook Creek. Alternative 2: Cut slopes could experience slope None Identified. None Construction of a instability. Identified. Roadway Underpass Cross-Valley Link, Relocation of the Union Pacific Railroad Track and, Modification of SW 27th Street to Five Lanes Cut walls used to retain slopes and None Identified. None excavations could lack soil and Identified. groundwater resistance. Underpass bottom seal/base slab could None Identified. None lack adequate resistance to groundwater Identified. uplift pressures. Fill settlement, instability, and lateral None Identified. None movement could impact underlying utilities Identified. or adjacent structures as well as walls or pavements constructed on the fill. Draft Geology and Soils Discipline Report 69 May 2004 Strander Boulevard Extension City of Renton ' DRAFT fCurrent design-level earthquakes could None Identified. None occur during the life of the project, causing Identified. liquefaction. The effects of liquefaction may include decrease of bearing capacity for existing shallow foundations, ground surface settlement, reduction in lateral and vertical capacity of new deep foundations, cut slope and fill instability, and lateral deflection of existing utilities. Liquefaction alone could cause large ground settlement. Poor subgrade preparation and/or design None Identified. None for proposed pavements could lead to Identified. settlement, potholes, cracks, and other roadway distress. Driving new pile foundations or temporary None Identified. None sheetpile shoring may cause vibration- Identified. induced ground settlements. Erosion of exposed cut or fill slopes could None Identified. None cause increased sediment transport onto Identified. other areas of the project, into stormwater drains, and into Springbrook Creek. Alternative 3: Cut slopes could experience slope None Identified. None Construction of a instability. Identified. Roadway Underpass Cross- Valley Link, Union Pacific Railroad Tracks NOT Relocated, and Modification of SW 27th Street to Five Lanes Cut walls used to retain slopes and None Identified. None excavations could lack soil and Identified. groundwater resistance. Underpass bottom seal/base slab could None Identified. None lack adequate resistance to groundwater Identified. uplift pressures. Fill settlement, instability, and lateral None Identified. None movement could impact underlying utilities Identified. or adjacent structures as well as walls or pavements constructed on the fill. Draft Geology and Soils Discipline Report 70 May 2004 Strander Boulevard Extension City of Renton DRAFT Current design-level earthquakes could None Identified. None occur during the life of the project, causing Identified. liquefaction. The effects of liquefaction may include decrease of bearing capacity for existing shallow foundations, ground surface settlement, reduction in lateral and vertical capacity of new deep foundations, cut slope and fill instability, and lateral deflection of existing utilities. Liquefaction alone could cause large ground settlement. Poor subgrade preparation and/or design None Identified. None for proposed pavements could lead to Identified. settlement, potholes, cracks, and other roadway distress. Driving new pile foundations or temporary None Identified. None sheetpile shoring may cause vibration- Identified. induced ground settlements. Erosion of exposed cut or fill slopes could None Identified. None cause increased sediment transport onto Identified. other areas of the project, into stormwater drains, and into Springbrook Creek. 7.0 REFERENCES American Railway Engineering and Maintenance-of-Way Association (AREMA). 1999. Manual for railway engineering, Landover, Maryland, American Railway Engineering and Maintenance-of-Way Association. Atwater, B.F. 1987. "Evidence for great Holocene earthquakes along the outer coast of Washington State"Science, Vol. 236, pp. 942-944. Federal Emergency Management Agency. 1995. Flood insurance rate map for King County, Washington and incorporated areas: Map No. 53033C097817, effective date May 16. Mullineaux, D. R. 1965. Geologic map of the Renton quadrangle, King County, Washington, U.S. Geological Survey Geologic Quadrangle Map GQ-405, 1 sheet, scale 1:24,000. Palmer, Stephen P., Schasse, Henry W.,Norman, David K. 1994. Liquefaction susceptibility for the Des Moines and Renton 7.5-minute quadrangles, Washington, Washington Division of Geology and Earth Resources Geologic Map GM-41, 2 sheets, scale 1:24,000, with 15 p. text. Draft Geology and Soils Discipline Report 71 May 2004 Strander Boulevard Extension City of Renton DRAFT Renton (Wash.). 2002. City of Renton sensitive areas and wetlands maps, erosion hazards, Renton(Wash.)., Technical Services, Planning, Building, Public Works, map available at http://www.ci.renton.wa.us/. Seed, R.B., Cetin, K.O., Moss, R.E.S., Kammerer,A.M., Wu, J., Pestana, J.M.,Riemer, M.F., Sancio, R.B., Bray, J.D., Kayen, R.E., and Faris,A. 2003. Recent advances in soil liquefaction engineering: a unified and consistent framework: 261h Annual American Society of Civil Engineers Los Angeles Geotechnical Spring Seminar, Keynote Presentation, H.M.S. Queen Mary, Long Beach, Calif. Shannon& Wilson, Inc. 2001. Draft Technical Memorandum, Strander Boulevard/SW 27th Street Corridor Improvements, Phase I Preliminary Geotechnical Information. Report by Shannon& Wilson, Inc., Seattle, Wash., 21-1-09369-001, for Berger/ABAM Engineers, Inc., Federal Way, Wash., May. Shannon& Wilson, Inc. 2004. Geotechnical Report, Strander Boulevard/SW 27th Street Improvements, Renton and Tukwila, Washington. Report by Shannon& Wilson, Inc., Seattle, Wash., 21-1-09369-002, for Perteet Engineering, Inc., Everett, Wash., February. Snyder, D.E., Gale, P.S., and Pringle, R.F. 1973. Soil Survey: King County Area, Washington. Washington, D.C., U.S. Department of Agriculture Soil Conservation Service and Washington Agricultural Experiment Station, U.S. government Printing Office Item No. 102-B-47,November, 100 p. Washington State Department of Transportation(WSDOT). 2003. Environmental Procedures Manual. M31-11. Web page available at: http://www.wsdot.wa.gov/fasc/En ing eeringPublications/Manuals/EPM/EPM.htm Draft Geology and Soils Discipline Report 72 May 2004 Strander Boulevard Extension City of Renton APPENDIX A SUBSURFACE EXPLORATIONS APPENDIX A SUBSURFACE EXPLORATIONS TABLE OF CONTENTS Page A.1 INTRODUCTION ....................................................................................................A-1 A.2 CURRENT SOIL BORINGS ................................................................................... A-1 A.2.1 Drilling Procedures..................................................................................... A-1 A.2.2 Soil Sampling............................................................................................. A-2 A.2.2.1 Thin-Walled Tube Samples ......................................................... A-2 A.2.2.2 Standard Penetration Test Samples..............................................A-3 A.2.3 Soil Classification.......................................................................................A-3 A.2.4 Monitoring Well Installation......................................................................A-3 A.2.5 Well Development...................................................................................... A-4 A.2.6 Vibrating Wire Piezometer Installation...................................................... A-4 A.2.7 Groundwater Observations......................................................................... A-4 A.2.8 Boring Logs................................................................................................ A-5 A.3 PREVIOUS FIELD EXPLORATIONS ...................................................................A-5 A.4 REFERENCE............................................................................................................ A-5 TABLE Table No. A-1 Previous Exploration Data LIST OF FIGURES Figure No. A-1 Soil Classification and Log Key(2 sheets) A-2 Log of Boring B-101 MW A-3 Log of Boring B-102 (2 sheets) A-4 Log of Boring B-103 (4 sheets) A-5 Log of Boring B-104 MW/VWP A-6 Log of Boring B-105 VWP (3 sheets) 21-1-09369-002-R2-AA.doc/wp/MSOffice 2 1-1-093 69-002 DRAFT �: A-i TABLE OF CONTENTS (cont.) LIST OF FIGURES (cont.) Figure No. A-7 Log g of Boring B-106 MWNVYT A-8 Log of Boring B-107 (3 sheets) 1 A-9 Log of Boring B-108 MWNVVT A-10 Log of Boring B-109 (2 sheets) A-11 Log of Boring B-110 MW A-12 Log of Boring B-111 A-13 Log of Boring B-112 A-14 Log of Boring B-201 A-15 Log of Boring B-202 A-16 Log of Boring B-203 A-17 Log of Boring B-204 A-18 Log of Boring B-205 A-19 Log of Boring B-301 (2 sheets) A-20 Log of Boring B-302 (2 sheets) �) A-21 Log of Boring B-303 A-22 Log of Boring B-304 A-23 Log of Test Pit TP-301 A-24 Log of Test Pit TP-302 A-25 Log of Test Pit TP-303 A-26 Log of Boring B-305 (2 sheets) A-27 Log of Boring B-306 (2 sheets) A-28 Log of Boring B-307 A-29 Log of Boring B-308 A-30 Log of Boring B-309 A-31 Log of Boring B-310 A-32 Log of Boring B-311 A-33 Log of Boring B-312 A-34 Log of Boring B-313 A-35 Log of Boring B-314 A-36 Log of Boring B-315 A-37 Log of Boring B-316 (2 sheets) A-38 Log of Test Pit TP-304 A-39 Log of Test Pit TP-305 A-40 Log of Boring B-317 A-41 Log of Test Pit TP-306 A-42 Log of Boring B-318 A-43 Log of Boring C-301 2 1-1-093 69-002-R2-AA /MSO ffice 21-1-09369-002 wp DRAFT A-ii APPENDIX A SUBSURFACE EXPLORATIONS A.1 INTRODUCTION The current subsurface exploration program consisted of drilling 17 borings and installing 5 monitoring wells and 4 vibrating wire piezometers (VWPs)between the West Valley Highway and East Valley Road. The boring locations are shown on the Site and Exploration Plan,presented as Figure 3.1 in the main text of the discipline report. The borings are designated B-101 through B-112 (Segment 1 from West Valley Highway to Oakesdale Avenue SW) and B-201 through B-205 (Segment 2 from Oakesdale Avenue SW to East Valley Road). In addition, several previous explorations from other studies were used. The approximate locations of the previous explorations are shown on Figure 3.1 in the main text of the report. Perteet Engineering, Inc. surveyed the locations and elevations of the 100-series borings completed in Segment 1 after completion of drilling operations. Elevations are relative to the NAVD88 datum. The approximate locations of the Segment 2 borings were determined by measuring from existing site features located on the site plan. The approximate locations of previous explorations by others were determined from previous reports and by measuring from existing site features located on the site plan. Plotting the exploration location on a topographic map provided by Perteet Engineering, Inc. approximated the elevations of the Segment 2 borings and the previous explorations. A.2 CURRENT SOIL BORINGS The subsurface conditions alongthe proposed 6 000-foot-lon project alignment were P P gp J � explored with 5 deep and 12 relatively shallow soil borings. The five deep borings, designated B-102, B-103, B-105 VWP, B-107, and B-109, were drilled to depths ranging from 101.5 to 181.5 feet. The 12 shallow borings, designated B-101 MW, B-104 MWNWP, B-106 MWNWP, B-108 MWNWP, B-110 MW through B-112, and B-201 through B-205,were drilled to depths ranging from 26.5 to 51.5 feet. The soil borings were accomplished between July 22 and August 6, 2003. A.2.1 Drilling Procedures Geo-Tech Explorations of Kent, Washington, drilled the soil borings under subcontract to Shannon& Wilson, Inc., using truck-mounted, drill rigs. The borings were drilled using open-hole mud-rotary methods. Mud rotary borings are advanced by circulating thick drilling mud from the rig down through standard 2%-inch outside-diameter(O.D.) rods to a 4'/s-inch or 6-inch-diameter tri-cone bit at the bottom of the borehole. The larger tri- cone bit was used at monitoring well and VWP locations. The drilling mud is a mixture of bentonite powder and water. Cuttings are transported from the bottom of the borehole to the surface by drilling mud flowing between the drilling rods and the sides of the 21-1-09369-002-R2-avwp/Msoffiee 21-1-09369-002 DRAFT A-1 i borehole. The cuttings are deposited in a settling tank at the ground surface and the mud is recirculated. Soil samples are taken from the bottom of the mud-filled open hole. For worker safety, field screening was performed to evaluate the potential for hydrocarbon contamination. Volatile screening techniques included the use of a photoionization detector (PID), which provides a qualitative measurement of the volatile organics in soil, as well as visual and olfactory observations on the soil samples obtained above and below the groundwater level, respectively. Based on the PID readings and visual/olfactory methods of observation, no signs of potential contamination were noted in any of the boreholes except boring B-203, sample S-3. In boring B-203, sample S-3, at a depth of about 7.5 feet below ground surface, an odor was detected using olfactory methods; an environmental sample was obtained and submitted for testing. The boring B-203 soil cuttings and drilling mud were transferred into three drums by the drilling subcontractor and stored on City of Tukwila property until environmental analytical testing was complete. After completion of drilling and sampling, all borings except those with monitoring well or VWP installations were sealed with bentonite grout and chips. Borings with monitoring wells and V WPs have an"MW" and "V WP" after the boring number (for example, B-104 MW/VWP has both a monitoring well and a VWP installation). All cuttings and drilling mud were left on City of Renton or City of Tukwila property. It is anticipated that Conoco-Phillips will take possession of the three drums containing potentially contaminated soils stored on City of Tukwila property. A.2.2 Soil Sampling tDuring drilling along the proposed alignment, representative soil samples were obtained. In general, soil samples were collected at 2.5-foot intervals to a depth of 30 feet and at 5- foot intervals thereafter. Two types of soil samplers were used: thin-walled tubes and standard split spoons. Symbols used on the boring logs indicate which sampler was used at each depth interval. The sampler types are discussed in the following sections. A.2.2.1 Thin-Walled Tube Samples Relatively undisturbed samples of cohesive soils were obtained using thin-walled (Shelby) tubes in general accordance with American Society for Testing and Materials (ASTM) Designation: D 1587, Standard Practice for Thin-Walled Tube Geotechmcal Sampling of Soils. This sampling method employs a 3-inch O.D. thin-walled, steel tube connected to a sampling head that is attached to the drill rods. The tube is slowly pushed by the hydraulic rams of the drill rig into the soil below the bottom of the drilled hole and then retracted to obtain a sample. The tube samples were classified in the field and recorded on the logs by the field representative. The tube samples were carefully sealed and transported upright to the Shannon & Wilson laboratory for testing. z 1-1-09369-ooz-xz-n vwprnMsoft;ce 21-1-093 69-002 DRAFT A-2 A.2.2.2 Standard Penetration Test Samples To obtain disturbed soil samples from borings, Standard Penetration Tests (SPTs) were performed in general accordance with the ASTM Designation: D 1586, Test Method for Penetration Test and Split-Barrel Sampling of Soils. In the SPT, a 2-inch O.D., 1.375- inch inside-diameter(I.D.), split-spoon sampler is driven with a 140-pound hammer falling 30 inches. The number of blows required to achieve each of three 6-inch increments of sampler penetration is recorded. The number of blows required to cause the last 12 inches of penetration is termed the Standard Penetration Resistance (N-value). The number of blows causing the last 12 inches of penetration is termed the Standard Penetration Resistance or blow count,N. When penetration resistances exceed 50 blows for 6 inches or less of penetration, the test is terminated and the number of blows recorded. The SPTs were recorded by the field representative and are plotted on the boring logs. These values are empirical parameters that provide a means of evaluating the relative density or compactness of cohesionless (granular) soils and the relative consistency (stiffness) of cohesive soils. The terminology used to describe the relative density or consistency of the soil is presented on Figure A-1. The split-spoon sampler used during the penetration testing recovers a relatively disturbed sample of the soil, which is useful for identification and classification purposes. The samples were classified and recorded on field logs by the Shannon & Wilson representative. The samples were sealed in jars and returned to the Shannon & Wilson laboratory for testing. A.2.3 Soil Classification An engineer or field representative from Shannon &Wilson, Inc. was present throughout the drilling and sampling operations of the current borings. The representative retrieved representative soil samples and prepared a descriptive field log of the explorations. Classification of the boring samples was based on ASTM Designation: D 2487-98, Standard Test Method for Classification of Soil for Engineering Purposes, and ASTM Designation: D 2488-93, Standard Recommended Practice for Description of Soils (Visual-Manual Procedure). The Unified Soil Classification System (USCS), as described on Figure A-1, was used to classify the soils encountered in the soil borings. The boring logs in this report represent the interpretation of the contents of the field logs. A.2.4 Monitoring Well Installation As part of the investigation, five monitoring wells were installed to evaluate groundwater conditions that may be encountered during construction. Each of the five wells was slug tested to estimate hydraulic parameters, and a pressure transducer/datalogger system was installed in the well closest to the Green River (boring B-101 MW) to monitor groundwater level fluctuations as compared to the Green River water level. Monitoring wells are designated with an "MW." Because the borings were performed using a mud 21-1-09369-002-R2-AA/wp/MSOffice 2 1-1-093 69-002 DRAFT A-3 rotary drilling rig, the drilling mud was pumped from the hole prior to installation of the well screen and riser pipe. The monitoring wells were constructed of new, commercially fabricated, threaded, flush jointed, 2-inch-diameter Schedule 40 polyvinyl chloride (PVC). Well screen generally consisted of new, commercially fabricated, threaded, 10-foot-long, flush- jointed, 2-inch-diameter, 0.01-inch-wide, machine-slotted screen. A silica sand filter pack was poured in the annular space between the boring and the well screen to about 2 to 3 feet above the screen. A minimum 2-foot-thick bentonite seal was placed in the annulus above the filter pack to within 3 feet of the surface. The wells were completed slightly higher than the elevation of the surrounding grade by placing an 8-inch-diameter flush-mount steel monument over the top of the borehole. The monuments were set above the adjacent grade to reduce surface water inflow. The steel monuments were set inplace with quick-set concrete. A.2.5 Well Development Monitoring well development was performed to enhance the hydraulic connection between the screened portion of the monitoring well and the surrounding soil. The development procedure consisted of a combination of surging and pumping. The saturated, screened section of each observation well was surged and pumped simultaneously to remove water, drilling mud, and sediment from the bottom of the well. Development equipment consisted of a WaterraTM 2-inch-diameter, Acetyl surge block/check-valve combination attached to the bottom of a dedicated section of semi- rigid, high-density polyethylene (HDPE) tubing. The sediment load of the purged groundwater was measured periodically by filling a container and observing the amount of sediment that settled out. Wells were pumped until no further improvement in water quality was observed. A.2.6 Vibrating Wire Piezometer Installation As part of the investigation, four VWPs were installed to evaluate groundwater conditions that may be encountered during construction. VWPs were installed in four borings and are designated with a"VWP." The V WPs were calibrated and hung at the target installation depths. With the exception of boring B-105, the VWPs were surrounded with filter pack sand from about 2 feet below the VWP tip to about 2 feet above the VWP. Bentonite chips were used to fill the annular space within the borehole except at well screen(see above) and VWP depths. Bentonite grout was used at boring B-105 to surround the VWP and fill the annular space within the borehole because of the difficulty placing the filter pack at the target installation depth. The VWP depths are shown on the boring logs. A.2.7 Groundwater Observations Where observed, groundwater was noted during drilling. Groundwater levels in the monitoring wells were also read after well development. Both the during-drilling and the 21-1-09369-002-x2-AA/wp/Ms0ffice 21-1-09369-002 DRAFT A-4 more recent groundwater level measurements from monitoring wells and VWPs are noted on the boring logs. These measurements may not be representative of the highest potential groundwater levels. A.2.8 Boring Logs The current boring logs for the proposed alignment are presented in this appendix. A boring log is a written record of the subsurface conditions encountered. It graphically illustrates the geologic units (layers) encountered in the boring and the Unified Soil Classification System (USCS) symbol of each geologic layer. It also includes the natural water content, blow count, and soil strength (where tested). Other information shown on the boring logs includes the groundwater level observations made during drilling, well and VWP construction information (if applicable), ground surface elevation, types and depths of sampling, and Atterberg Limits (where tested). A.3 PREVIOUS FIELD EXPLORATIONS Several previous subsurface explorations were also used in the study; the approximate locations of these explorations are shown on the Site and Exploration Plan, Figure 3.1, in the main text of the discipline report. The previous subsurface explorations include 18 soil borings, 6 test pits, and 1 Dutch cone penetration test (CPT), designated B-301 through B-318, TP-301 through TP-306, and C-301, respectively. Table A-1 of this appendix summarizes the consultant, project name, completion date, designations, and other figure number for each of the previous explorations. The logs for these explorations are presented as Figures A-19 through A-43. The locations of the explorations were estimated from previous report site plans. A.4 REFERENCE American Society for Testing and Materials (ASTM), 2003, 2003 Annual book of standards, Construction, v. 04.08, Soil and rock (I): D 420—D 5779: West Conshohocken, Pa. 21-1-09369-002-x2-nniwp/MSO eye 21-1-09369-002 DRAFT A-5 SHANNON &WILSON, INC. TABLE A-1 PREVIOUS EXPLORATION DATA Exploration Designation _Figure r77 Consultant Projeet Name r Date Previous New .Number'`' Rittenhouse-Zeman&Associates,Inc. Jack in the Box#8443 June-87 B-1 B-301 A-19 GeoEngineers,Inc. Boeing Longacres Site December-90 16 B-302 A-20 Earth Consultants,Inc. Proposed Warehouse on SW 27th Street July-87 B B-303 A-21 A B-304 A-22 Earth Consultants,Inc. SW 27th Street Warehouse August-94 TP-1 TP-301 A-23 TP-13 TP-302 A-24 TP-2 TP-303 A-25 HWA GeoSciences,Inc. SW 27th Street Culvert Replacement October-98 BH-2 B-305 A-26 BH-1 B-306 A-27 Landau Associates,Inc. Conoco Phillips Tosco Renton Terminal November-02 LAI-15 B-307 A-28 LAI-12 B-308 A-29 LAI-II B-309 A-30 LAI-10 B-310 A-31 LAI-1 B-311 A-32 LAI-2 B-312 A-33 LAI-3 B-313 A-34 LAI-16 B-314 A-35 GeoEngineers,Inc. Proposed Stores Building February-82 5 B-315 A-36 1 B-316 A-37 TP-7 TP-304 A-38 TP-16 TP-305 A-39 Environmental Associates,Inc. Proposed Lind Avenue Warehouse August-94 B-1 B-317 A-40 TP-7 TP-306 A-41 Earth Consultants,Inc. Proposed Manufacturing Site January-85 1 B-318 A-42 P-1 C-301 A-43 Notes: B=Boring C=Dutch Cone Penetration TP=Test Pit 21-1-09369-002-R1-TA-1.x1s 21-1-09369-002 Shannon& Wilson, Inc. (S&W), uses a soil GRAIN SIZE DEFINITION classification system modified from the Unified DESCRIPTION SIEVE NUMBER AND/OR SIZE Soil Classification System(USCS). Elements of the USCS and other definitions are provided on FINES <#200(0.08 mm) this and the following page. Soil descriptions are based on visual-manual procedures(ASTM SAND' D 2488-93) unless otherwise noted. Medium #400 t Fine # too#10((0.080.4 to 2 2 mm) mm) - to Coarse #10 to#4(2 to 5 mm) S&W CLASSIFICATION GRAVEL' OF SOIL CONSTITUENTS -Fine #4 to 3/4 inch(5 to 19 mm) MAJOR constituents compose more than 50 -Coarse 3/4 to 3 inches(19 to 76 mm) percent,by weight,of the soil. Major consituents are capitalized (i.e.,SAND). COBBLES 3 to 12 inches(76 to 305 mm) • Minor constituents compose 12 to 50 percent of the soil and precede the major constituents BOULDERS > 12 inches(305 mm) (i.e., silty SAND). Minor Constituents 'Unless otherwise noted,sand and gravel,when preceded by"slightly' compose 5 to 12 present,range from fine to coarse in grain size. percent of the soil(i.e., slightly silty SAND). • Trace constituents compose 0 to 5 percent of RELATIVE DENSITY/CONSISTENCY the soil(i.e.,slightly silty SAND,trace of gravel). COARSE-GRAINED SOILS FINE-GRAINED SOILS N, SPT, RELATIVE N,SPT, RELATIVE MOISTURE CONTENT DEFINITIONS BLOWS/FT. DENSITY BLOWS/FT. CONSISTENCY Dry Absence of moisture, dusty, dry 0-4 Very loose Under 2 Very soft to the touch 4-10 Loose 2-4 Soft 10-30 Medium dense 4-8 Medium stiff Moist Damp but no visible water 30-50 Dense 8-15 Stiff Wet Visible free water, from below Over 50 Very dense 15-30 Very stiff water table Over 30 Hard ABBREVIATIONS WELL AND OTHER SYMBOLS ATD At Time of Drilling ® %,.Bent.Cement Grout ;��:;� Surface Cement Elev. Elevation Seal ft feet ® Bentonite Grout Asphalt or Cap FeO Iron Oxide MgO Magnesium Oxide Bentonite Chips Slough HSA Hollow Stem Auger Silica Sand ® Bedrock ID Inside Diameter in inches PVC Screen Ibs pounds m Mon. Monument cover Vibrating Wire N Blows for last two 6-inch increments NA Not applicable or not available NP Non plastic OD Outside diameter OVA Organic vapor analyzer PID Photo-ionization detector N F_ ppm parts per million PVC Polyvinyl Chloride Strander Boulevard/SW 27th Street 3 SS Split spoon sampler Improvements ti SPT Standard penetration test Renton and Tukwila, Washington a C� USC Unified soil classification WLI Water level indicator SOIL CLASSIFICATION En AND LOG KEY En February 2004 21 1-09369-002 c�El SHANNON & WILSON, INC. FIG. A 0 Geotechnical and Environmental consultants Sheet 1 of 2 UNIFIED SOIL CLASSIFICATION SYSTEM (USCS) (From ASTM D 2487-98 &2488-93) MAJOR DIVISIONS GROUP/GRAPHIC SYMBOL TYPICAL DESCRIPTION • Well- aded ravels,q avels, GW , grave��sand r ixtures,litlle or,no fines Clean Gravels (less than 5% Gravels fines) GP Poorly gsradee or ravels f nesravel-sand mixtur(more than 50% o of coarse fraction retained on No.4 sieve) Gravels with GM Silty gravels,gravel-sand-silt mixtures Fines COARSE (more than 12% GRAINED fines) GC Clayey gravels,gravel-sand-clay SOILS mixtures (more than 50% retained on No. SW Well-graded sands,gravelly sands, 200 sieve) Clean Sands little or no fines (less than 5% fines) Poorly graded sand,gravelly sands, Sands SIP little or no fines (50%or more of coarse fraction ' passes the No.4 SM Silty sands,sand silt mixtures sieve) Sands with Fines (more than 12% fines) SC Clayey sands,sand-clay mixtures Inorganic silts of low to medium ML' plasticity,rock flour,sandy silts,gravelly silts,or clayey silts with slight Inorganic plasticity Silts and Clays Inorganic clays of low to medium (liquid limit less CL plasticity,gravelly clays,sandy clays, than 50) silty clays,lean clays FINE-GRAINED Organic OL == Organic silts and organic silty clays of SOILS g _ low plasticity (50%or more - passes the No. Inorganic silts,micaceous or 200 sieve) MH diatomaceous fine sands or silty soils, elastic silt Inorganic Silts and Clays Inorganic clays or medium to high (liquid limit 50 or CH plasticity,sandy fat clay,or gravelly fat more) clay Organic OH / Organic clays of medium to high /� plasticity,organic silts ORGANIC Primarily organic matter,dark in PT Peat,humus,swamp soils with high SOILS color,and organic odor organic content(see ASTM D 4427) a 0 P Strander Boulevard/SW 27th Street 3 NOTES Improvements Renton and Tukwila,Washington 1.Dual symbols(symbols separated by a hyphen,i.e.,SP-SM,slightly silty fine SAND)are used for soils with between 5%and 12%fines SOIL CLASSIFICATION 0 or when the liquid limit and plasticity index values plot in the CL-ML area of the plasticity chart. AND LOG KEY N U 2.Borderline symbols (symbols separated by a slash,i.e., CL/ML,silty February 2004 21-1-09369-002 CLAY/clayey SILT, G W/SW,sandy GRAVEUgravelly SAND) z indicate that the soil may fall into one of two possible basic groups. SHANNON &WILSON, INC. I FIG. A-1 m Geotechnical and Environmental Consultants Sheet 2 of-2 SOIL DESCRIPTION a) 1 Standard Penetration Resistance o E Cn s E a a o m (140 lb.weight,30-inch drop) a cn o � C A Blows per foot Surface Elevation:30.1 Ft.Datum:NAVD88 t� a U) p 0 20 40 60 Medium dense, gray,silty,clayey, fine ' gravelly SAND; moist; scattered organics; (Hf) SM. o ,I Loose to medium dense, brown to dark 4.5 5 - -- - -- - gray,trace to slightly clayey, slightly silty to o zI• silty,fine SAND; moist to wet; trace of 0 3I N Ni organics;scattered iron oxide staining T Tbetween 12.5 and 14 feet below ground 0 4 - - 1 10 - - - - - -®-- surface(bgs); (HaD)SP-SM. •. . 0 5� Very soft to soft, dark ra trace to sli htl 14.5 15 --- ----!---- fine sandy,clayey SILT and silty CLAY with o s= . . . . . . i . . . . numerous layers of loose,silty, fine sand; ! . . . . .. . . wet;scattered to numerous organics and N 61 wood fragments;scattered iron oxide s 20 - ----- ---- -'--- --- --- staining between 15 and 16.5 feet bgs; (HeD with thin Hp layers) MUCL. eI � I 25 - O 128 Medium dense to dense, dark trace to 29.5 gray, 30 — - 9 Y. ,zI ---- slightly silty, fine to medium SAND;wet; scattered organics;trace of gravel in sample S-15; (HaD) SP-SM. ,3I 35 -------. . i ® ---- ---- i i taI Z 40 - -. . . � . . . - ---- i a NOTE: Sulphur odor noted during well 151 45 — -- - - `� development. . . . . . . . . . j . . . . . . m U -- . —--- m • 50 16� . �I . x BOTTOM OF BORING 51.5 g COMPLETED 7/22/2003 . . . . . . . . t. 1 . . . . . .. J I LEGEND 0 20 40 60 Sample Not Recovered Piezometer Screen and Sand Filter • %Water Content I Standard Penetration Test ® Bentonite-cement Grout Plastic Limit 1 — 0 Liquid Limit o Ij Thin Wall Sample ® Bentonite Chips/Pellets Natural Water Content a ® Bentonite Grout SV Ground Water Level ATD Strander Boulevard/SW 27th Street T Ground Water Level in Well Improvements NOTES Renton and Tukwila,Washington 2 1.The boring was performed using Mud Rotary drilling methods. m 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-101 MW 0 3.The discussion in the text of this report is necessary for a proper understanding of the N nature of the subsurface materials. N 0 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 w 5.Refer to KEY for explanation of symbols,codes and definitions. a 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON &WILSON, INC. FIG. A-2 Geotechnical and Environmental Consultants SOIL DESCRIPTION u- o E tL Standard Penetration Resistance t E a o o s (140 lb.weight, 30-inch drop) o M A Blows per foot Surface Elevation:27.3 Ft.Datum: NAVD88 p a to p 0 20 40 60 Loose,brown, silty, fine SAND; moist; scattered organics; (HaD)SM. ° tI - - - ®--- Soft, brown,slightly fine sandy, clayey 5.0 ° zI 5 SILT; moist; iron oxide staining; scattered 7.0 Q or anics; HeD ML. o 3I Loose,dark gray, silty,fine SAND;wet; 9.5 0 10 iron-oxide staining; scattered organics; ° 4= ���LLL o HaD SP-SM. . . . . Very soft to to medium stiff,trace to slightly s j fine sandy,clayey SILT and silty CLAY with ° 6 15 --__-- several layers of very loose to loose,silty, y fine sand;wet;scattered to numerous organics and wood fragments;scattered '� j . . . . iron oxide staining between 10 and 11.5 20 -- - ------- ------ --- -- feet below ground surface(bgs); layers of 6 100 peat between 25 and 27 feet bgs; (HeD s with thin Hp layers) MUCUOL. gggg 25 - --- -- ---------- 92 10 I ' tt i t zI 30 --- ------ -----I--=O---- 14 Dense,dark gray,trace to slightly silty,fine 33.0 to medium SAND;wet;scattered organics 35 -------+ -- --=--- — and wood fragments; scattered silty clay 13� lenses;(HaD) SP-SM. l4I 40 -----. . . -® -- -- ----- . . . . . . . . . . . . Y tsI 45 ---------� ---- -- --- � j m 16� 50 j . . . . . j . . . . . . . . CONTINUED NEXT SHEET LEGEND 0 20 47 60 Sample Not Recovered I Ground Water Level ATD 0 %Water Content = Standard Penetration Test Plastic Limit 1 0 Liquid Limit o I[ Thin Wall Sample Natural Water Content r a o Strander Boulevard/SW 27th Street c� CL Improvements F NOTES Renton and Tukwila, Washington 2 1.The boring was performed using Mud Rotary drilling methods. 6 2.The stratification lines represent the approximate boundaries between soil types,and m the transition may be gradual. LOG OF BORING B-1 U2 3.The discussion in the text of this report is necessary for a proper understanding of the N nature of the subsurface materials. p 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 cr w 5.Refer to KEY for explanation of symbols,codes and definitions. 6.USCS designation is based on visual-manual classification and selected lab testin SHANNON & WILSON, INC. FIG. A-3 a g' Geolechnical and Environmental Consultants $heat 1 Of 2 SOIL DESCRIPTION L o E a - li Standard Penetration Resistance s E a n. o m (140 lb.weight, 30 inch drop) U) o m (D Blows per foot Surface Elevation:27.3 Ft. Datum: NAVD88 d U) 0 0 20 44 60 rr 60 ,aI 65 -- 19 70 O.. 20 75 -- -- -® ------ -- 21 Stiff to very soft, gray,slightly fine sandy to 78.0 I fine sandy,slightly clayey to clayey SILT 80 ------ ------ ---0 - ------ and silty CLAY with trace of fine sand;wet; 22I layers of silty,fine sand; numerous organics; (HeD) MUCL j 85 - - �� 0 -- ----- 23 1 1 2QI 90 --- ---- --_._...__�. ------- i i zsI 95 ---- - ----®. i -- o I . 100 Y --- J 26 ~ BOTTOM OF BORING 101.5 m COMPLETED 7/23/2003105 U i LEGEND 0 20 40 60 Sample Not Recovered y- Ground Water Level ATD 0 %Water Content I Standard Penetration Test Plastic Limit f--♦— Liquid Limit o I[ Thin Wall Sample Natural Water Content N o Strander Boulevard/SW 27th Street c� EL Improvements E � NOTES Renton and Tukwila,Washington a' 1.The boring was performed using Mud Rotary drilling methods. m 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-102 3.The discussion in the text of this report is necessary for a proper understanding of the N nature of the subsurface materials. p 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 w 5.Refer to KEY for explanation of symbols,codes and definitions. uU) 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON & WILSON, INC. FIG. A-3 Geotechnical and Environmental Consultants Sheet 2 of 2 t SOIL DESCRIPTION LL o E li Standard Penetration Resistance s E a a o r (140 lb.weight, 30-inch drop) a 0> o � C A Blows per foot Surface Elevation:25.9 Ft. Datum:NAVD88 p a p 0 20 40 60 Interbedded, loose,brown,silty, fine SAND and medium stiff to soft,fine sandy, clayey • SILT; moist to wet;scattered organics; 0.3 ,I iron oxide staining between 5 and 6.5 feet 5 below ground surface(bgs); (HaD) SM/ML. : 0.3 21 . . . . I . . . Very soft to soft, dark gray,slightly to fine 7'0 ® . sandy,clayey SILT and silty CLAY with 0.3 3I Q several layers of very loose,silty,fine sand; o s a 10 ---- --- --- - m- wet, scattered iron-oxide staining; scattered o to numerous organics and wood fragments; 0.6 5I layers of dark brown peat encountered between 22.5 and 24 feet bgs; (HeD with 0.3 sI 15 ------.!- -C - - - Hp layers) MH/CH/OH. 64 7z I 20 - -------r----- -® - - --- 8 104 9I gray, I - - -- - O - - 25 --�-- — 26.0 ,o i Medium dense to dense,dark ra trace to slightly silty,fine to medium SAND;wet; scattered to numerous wood fragments between 27.5 and 29 ft bgs; (HaD) SP-SM. 12� 30 e-- I 35 13� . . . . I . . 40 --- --0--- i14 I I J 45 cl ,SI •. ,8� 50 —. I k . . . . . . � . ° CONTINUED NEXT SHEET � I LEGEND 0 20 40 60 Sample Not Recovered 2 Ground Water Level ATD 0 %Water Content I Standard Penetration Test Plastic Limit Liquid Limit o I[ Thin Wall Sample Natural Water Content N 1 o Strander Boulevard/SW 27th Street c� Improvements F NOTES Renton and Tukwila,Washington 2 1.The boring was performed using Mud Rotary drilling methods. m 2.The stralification lines represent the approximate boundaries between soil types,and m the transition may be gradual. OF BORING" B-103 3.The discussion in the text of this report is necessary for a proper understanding of the LOG r 1�I 1 N nature of the subsurface materials. N 0 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 w 5.Refer to KEY for explanation of symbols,codes and definitions. (n 6.USCS designation is based on visual-manual classification and selected lab testing. $HANNON & WILSON, INC. FIG. Q-4 a Geotechnical and Environmental Consultants Sheet 1 of 4 SOIL DESCRIPTION u- -5 E �, o U_ Standard Penetration Resistance L E Q a- o r (140 lb.weight, 30-inch drop) Q) ct) o_ Ca Blows per foot Surface Elevation:25.9 Ft. Datum: NAVD88 0 a U) 0 0 20 40 60 n ' 60 m --- --- 18� 65 _®-- 19 1 j Medium dense,dark gray,trace to slightly 66.5 clayey,fine sandy SILT;wet; scattered j organics and wood fragments; (HeD) ML. 70 _0! 20 73.0 . . . . . . � . . . . . Medium stiff to very soft,gray,slightly clayey to clayey SILT and silty CLAY with TT 75 -- ---_---'-----------__-�_i --_ - layers of medium dense,silty, fine sand; 21 L wet;scattered to numerous organics and wood fragments;(HeC) MUCL. . . . . 80 -- — - - ----- --- ——- -- -- 22 2I 85 s - ------ -- ---}-�------ 1 90 . . . . . . . . — za � I 93.0 25 I . . . . . . . . Very soft to medium stiff, gray,slightly ; �.. . ; _ . . � . . . . . clayey to clayey SILT and silty CLAY with 95 ---- ------- —®- — layers of medium dense,silty,fine sand; zsI wet;scattered to numerous organics and i o wood fragments; (HeD) MUCL. z� 100 --- -- ---- fD—i- a I i I . . . . -- � 1 zeI 105 ; —I--- CI--- 108.0 . . . . . . ° CONTINUED NEXT SHEET ! LEGEND 0 20 40 60 Sample Not Recovered Ground Water Level ATD 0 %Water Content I Standard Penetration Test Plastic Limit Liquid Limit Ij Thin Wall Sample Natural Water Content a o Strander Boulevard/SW 27th Street IL Improvements F NOTES Renton and Tukwila,Washington a 1.The boring was performed using Mud Rotary drilling methods. o; 2.The stratification lines represent the approximate boundaries between soil types,and m the transition may be gradual. LOG OF BORING 13-103 y 3.The discussion in the text of this report is necessary for a proper understanding of the N nature of the subsurface materials. 1 0 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 w 5.Refer to KEY for explanation of symbols,codes and definitions. N 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON &WILSON, INC. FIG. A-4 ¢ Geotechnical and Environmental Consultants Sheet 2 Of 4 SOIL DESCRIPTION U_ o E � ti Standard Penetration Resistance >= E 0- o m .c (140 lb.weight, 30-inch drop) cn o C ♦ Blows per foot Surface Elevation:25.9 Ft. Datum:NAVD88 p a cn p 0 20 40 0 Very dense, dark gray,trace to slightly silty, sandy GRAVEL;wet;cobbles are potentially present; (Hag) GW-GM. 30= 115 -- - ._ - -----. NOTE: 5or5° 1. Difficult drilling. 2. Broken pieces of rock may have increased blow counts. 120 --p--- 31 Stiff,dark gray, silty CLAY with trace fine 123.0 sand; wet;scattered organics; (HeC) CL. 125 ----- ----------------® --- — 32 Very dense to dense,dark gray,slightly 127.0 silty,fine and fine to medium SAND;wet; --------- --- - ---- --— trace fine organics;scattered silt lenses; 130 ®33� 135 -------- - - - -- - — 34� - o . Very dense, gray,slightly sandy to sandy 138.0 GRAVEL,trace of silt and clay;wet; 140 -- -- -- ------ ®------- -- scattered layers of medium dense,slightly 35I . . . . silty to silty, slightly fine gravelly, fine sand; (Hag) GP. . . . . . . 36= 145 --® . . . .--------- - 50/3" 37— 150 ---0-- ----------'- 50/3- i a NOTE: Lost drilling mud from about 140 to 38=" 155 50/6" z 165 feet-making drilling difficult. . . m 160 0 I -- - ----- -- i cc 39� . . . . . . . . . . . 67 CONTINUED NEXT SHEET LEGEND 0 20 40 60 Sample Not Recovered 2 Ground Water Level ATD 40 %Water Content I Standard Penetration Test Plastic Limit F—♦— Liquid Limit o Thin wall Sample Natural Water Content r a o Strander Boulevard/SW 27th Street 0 Improvements LU NOTES Renton and Tukwila,Washington a 1.The boring was performed using Mud Rotary drilling methods. 6 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-103 3.The discussion in the text of this report is necessary for a proper understanding of the N nature of the subsurface materials. 0 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 0 w 5.Refer to KEY for explanation of symbols,codes and definitions. N 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON & WILSON, INC. FIG. A-4 ultants Sheet 3 Of 4 SOIL DESCRIPTION u Z E li Standard Penetration Resistance c E a 0- o s (140 lb.weight, 30-inch drop) o m 2 ♦ Blows per foot Surface Elevation: 25.9 Ft.Datum: NAVD88 O d U) 0 20 40 60 40 169.0 -- . - - ---- - Very dense,dark gray,slightly silty,fine to 170 ----Q -- medium SAND,trace of coarse sand and at I 68 fine gravel;wet; grades to gravelly in sample S-43; (Qva) SP-SM. 42Z 175 -- Q- ----- s -50/5 j 43= 180 ------ —® ----- - 5ois" BOTTOM OF BORING 180.9 COMPLETED 7/24/2003 185 -- --- -- ------ - -------- 190 ------ - -- -------+-- ------ 195 -------- -------— ----- 200 --- ---- -- --- I i 205 ---� I o --------'—--- --- . . . . 210 ---�— ii I U 215 ---- ------ —. . . . . . i � I LEGEND 0 20 40 60 Sample Not Recovered Ground Water Level ATD %Water Content I Standard Penetration Test TT Thin wall Sample Plastic Limit f----0--� Liquid Limit 'o Natural Water Content r N o Strander Boulevard/SW 27th Street Improvements ui NOTES Renton and Tukwila,Washington a' 1.The boring was performed using Mud Rotary drilling methods. m 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-1 U3 3.The discussion in the text of this report is necessary for a proper understanding of the a nature of the subsurface materials. N p 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 w 5.Refer to KEY for explanation of symbols,codes and definitions- 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON & WILSON, INC. FIG. A-4 a Geotechnical and Environmental Consultants Sheet 4 of 4 SOIL DESCRIPTION LL '5 E ILL Standard Penetration Resistance r E Q o t (140 lb.weight, 30-inch drop) cn o rEa A Blows per foot Surface Elevation:25.8 Ft.Datum:NAVD88 Q a- U) 0 p 0 20 40 60 Very soft, brown mottled,clayey SILT; moist to wet; layers of silty,fine sand; T I-- scattered to numerous organics; iron oxide o 1 1 staining; (HeD) ML. 5 — o zI ---. — Very loose to loose, dark gray, silty,fine 0 0.2 sI Y ®' SAND;wet;occasional organics; (HaD) SP-SM. o aI 10 - -- ----------®. . . - --- --- N 0 5� N I '• . Very soft to soft,gray,clayey SILT with 14.5 15 - — --- — — - ®- 0 6 trace fine sand and silty CLAY;wet; scattered organics and wood fragments; j . . . 0 7 (HeD) MUCL. o a= 20 m 23.0 Loose to very dense,dark gray,silty e grading to slightly silty,fine to medium 25 ----- -- -_--- _o SAND;wet;scattered organics;layers of 10� fine to coarse sand with trace of silt; (HaD) „I . tzI 30 - —---- -®— --- -------- t°I 35 ----- . I ——. . ' . . 40 —® ; ,4I 45 ---- cl 15� I . . . . . . . U —---- ------ 50 I 51.5 16I � . . . . BOTTOM OF BORING . . . . . . . . . . . . a COMPLETED 7/25/2003 . . . . . . . . . . . . . . I . LEGEND 0 20 40 60 Sample Not Recovered = Piezometer Screen and Sand Filter 0 %Water Content Standard Penetration Test ® Bentonite-Cement Grout Plastic Limit I—is—I Liquid Limit o ® Bentonite Chips/Pellets Natural Water Content a ® Bentonite Grout 2 Ground Water Level ATD � Strander Boulevard/SW 27th Street a __T Ground Water Level in Well Y Ground Water Level in VWP Improvements NOTES Renton and Tukwila,Washington 2 1.The boring was performed using Mud Rotary drilling methods. q m 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual- 0 LOG OF BORING B-104 M WN W 3.The discussion in the text of this report is necessary for a proper understanding of the N nature of the subsurface materials. o 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 cr w 5.Refer to KEY for explanation of symbols,codes and definitions. Cn 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON &WILSON, INFFI(G -sF . 5Q SOIL DESCRIPTION o ti Standard Penetration Resistance y E o- S (140 lb.weight, 30-inch drop) Surface Elevation:26.5 Ft. Datum:NAVD88 p U) in Blows per foot 0 20 40 60 Loose, brown, slightly fine sandy SILT; moist; scattered organics; (Hf) ML. I ----= - =• -- 4.0 Very soft to soft, brown,clayey SILT,trace _ fine sand;wet below 7 feet; scattered iron 2 5 oxide staining;scattered organics; layer of silty, fine sand in sample S-2;(HeD) ML. sI H 10.2 10 ----------'-- -fa---- -- --- -- Very loose, brown, silty,fine SAND and fine aI sandy SILT;wet; (HaD) SM/ML. I SI Very soft,gray,clayey SILT with trace of fine 16.0 6I 72 sand and silty CLAY with numerous layers of 7� loose,fine sandy silt and silty,fine sand;wet; scattered to numerous organics and wood eI 20 - 63 fragments;scattered iron oxide staining; peat layers between 22.5 and 28 feet bgs; (HeD 91 with layers of Hp) MUCUOL. 25 126 Medium dense to dense,dark gray,trace to 30.5 12 I 30 --- ------- _-0 ------- slightly silty,fine to medium SAND;wet; layers of fine to coarse sand;scattered organics; . . . . . (HaD)SP-SM. ,sT 35 ®--. . ...-------- . . . . . . . . . . 14T 40 0 ---- --- -- --- - 1 j 45 -- . . . -� ---- ------ - 15I 15I 50 m I I � CONTINUED NEXT SHEET I I LEGEND 0 20 40 60 Sample Not Recovered = Piezometer Screen and Sand Filter 0 %Water Content I Standard Penetration Test ® Bentonite-Cement Grout Plastic Limit 1--0 Liquid Limit o I[ Thin Wall Sample ® Bentonite Chips/Pellets Natural Water Content a ® Bentonite Grout o SZ Ground Water Level ATD Strander Boulevard/SW 27th Street i Ground Water Level in Well Improvements w NOTES Y Ground Water Level in VWP Renton and Tukwila,Washington a' 1.The boring was performed using Mud Rotary drilling methods. m 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-105 V W P - 3.The discussion in the text of this report is necessary for a proper understanding of the N nature of the subsurface materials. 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 0 w 5.Refer to KEY for explanation of symbols,codes and definitions. N 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON & WILSON, INC. FIG. A-6 g. Geotechnical and Environmental Consultants Sheet 1 of 3 1 SOIL DESCRIPTION U_ o a L li Standard Penetration Resistance E o s (140 lb.weight, 30-inch drop) Surface Elevation:26.5 Ft.Datum: NAVD88 pa) U) cn (D ) A Blows per foot 0 20 40 60 ,7IV X. 60 65 -- -- -------® -= -----.- -.... 19� 70.5 70 ---— ----- —�-- ----------- Soft to very soft,dark gray,slightly fine sandy 20� to fine sandy, slightly clayey to clayey SILT and silty CLAY;wet;layers of medium dense, silty,fine to medium sand; scattered organics; 75 ---- ----- < ------�'------ -- 21 (HeD) MUCL. 80 -- —— ---- - 22�' 85 ----- _— --- 23 Medium dense, dark gray,fine to medium 88.0 SAND,trace silt;wet;scattered organics; 9 0 --- -- trace shell fragments;(HaC)i SP. "': 24I j . . . . . _ i 94.0 . . . . . . . . . . . . . . Very soft to very stiff,dark gray, slightly fine 95 r sandy to fine sandy,slightly clayey to clayey 25I SILT and silty CLAY;wet; scattered organics; o (HeC) MUCL. . . . . 100 28 - .•.I . m 27 I . m ¢ 105 O----- 29 108.0 ° CONTINUED NEXT SHEET • I - LEGEND 0 20 40 60 Sample Not Recovered ( Piezometer Screen and Sand Filter 0 %Water Content I Standard Penetration Test ® Bentonite-Cement Grout Plastic Limit a 0 Liquid Limit 'o Thin Wall Sample ® Bentonite Chips/Pellets Natural Water Content ® Bentonite Grout N SZ Ground Water Level ATD Strander Boulevard/SW 27th Street 0 _T Ground Water Level in Well Y Ground Water Level in VWP Improvements NOTES Renton and Tukwila,Washington 1.The boring was performed using Mud Rotary drilling methods. o; 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-105 V W P 3.The discussion in the text of this report is necessary for a proper understanding of the a nature of the subsurface materials. 0 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 5.Refer to KEY for explanation of symbols,codes and definitions. W NC. - y 6.USCS designation is based on visual-manual classification and selected lab testing. a SHANNON &WILSON I FIG. A 6 Geotechnical and Environmental Consultants Sheet 2 of 3 SOIL DESCRIPTION li `n o li Standard Penetration Resistance t E a o ro r (140 lb.weight, 30-inch drop) aCL) co m 0EL A Blows per foot Surface Elevation:26.5 Ft. Datum:NAVD88 0 to 0 20 40 60 Very dense, gray, trace to slightly silty,sandy, GRAVEL;wet; layers of slightly silty, gravelly sand; (Hag) GW-GM. 30= 115 ---O _...._ -50/4.5" • —' -- - . 3 t 120 -----m ----__70 I 123.0 Interbedded,very soft,gray, silty CLAY and medium stiff,clayey, sandy SILT;wet; (HeC) 125 ----- - -- -- ® ------------ CUML 32= Medium dense, gray,slightly silty to silty,fine 127.0 SAND;wet; layers of fine sandy silt;scattered organics;(HaC) SP-SM. 130 --- - - - --- ---._..-—- 33 i 135 --- --- ... - -..—-----— 34 I 139.5 Very dense, gray,slightly silty, sandy 35= 140 ---0-- ---, -- ----66 AL GRAVEL,trace of clay;wet;layers of silty, fine sand and silty, gravelly sand;scattered organics;cobbles are potentially present; 36= 145 ®— --•-----._.._ (Hag) GW-GM. —. ..._ 5016'r i . . . • 37S 150 --50/5"- i 152.0 BOTTOM OF BORING o COMPLETED 7/25/2003 -- - --- - NOTE: Lost large amounts of drilling mud 155 (starting at about 151.5 feet). Driling m very difficult. Could not advance boring beyond 152 feet below ground 160 — ----- -- rr surface using mud rotary drilling x methods-placed vibrating wire at I gbottom of boring. . . . . . LEGEND 0 20 40 60 Sample Not Recovered Piezometer Screen and Sand Filter %Water Content Standard Penetration Test ® Bentonite-Cement Grout Plastic Limit I-0 Liquid Limit c I[ Thin Wall Sample ® Bentonite Chips/Pellets Natural Water Content a ® Bentonite Grout o Q Ground Water Level ATD Strander Boulevard/SW 27th Street L a Ground Water Level in Well Improvements NOTES Ground Water Level in VWP Renton and Tukwila,Washington a 1.The boring was performed using Mud Rotary drilling methods. 0ii 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-105 VWP 3.The discussion in the text of this report is necessary for a proper understanding of the N nature of the subsurface materials. 1 p 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 w 5.Refer to KEY for explanation of symbols,codes and definitions. C N 6.USCS designation is based on visual-manual classification and selected tab testing. SHANNON & WILSON9 INC. FIG. Q-V Geotechnical and Environmental Consultants Sheet 3 of 3 SOIL DESCRIPTION ti .n E -0 Standard Penetration Resistance s E a a o y (140 lb.weight, 30-inch drop) o m A Blows per foot Surface Elevation:23.9 Ft.Datum:NAVD88 0 a U) p 0 20 40 60 Loose,brown, trace to slightly clayey, silty, ' fine SAND and fine sandy SILT; moist to • wet; scattered iron oxide staining; scattered o ,I organics; (HeD) MUSM. --___------ 0.1 2� _ Loose,dark gray, slightly silty to silty,fine 7.0 N 0 31 \: SAND;wet;scattered iron oxide staining; scattered organics; (HaD) SP-SM/SM. 10 - -- -------- - O -- - ----- o a= Very soft to soft, dark gray,trace fine sandy 12"0 o sI g to fine sandy,slightly clayey to clayey SILT and silty CLAY;wet; scattered to numerous 15 o a= ---------r- --��-~----® --_-- organics and wood fragments;scattered _L shell fragments in sample S-10; layers of . . dark brown peat between 22.5 and 26.5 I 20 - ---- ----- -- --- - 62 feet below ground surface (bgs); burnt 6 wood fragments encountered at about 26.3 ias feet bgs; (HeD) MUCUOL. 9I 25 -- _ .. - - -- -- -----..®NP ,oI Medium dense to dense,dark gray, slightly 26.5 silty to silty,fine to medium SAND,trace of clay; wet;layers of fine to coarse sand; 30 -------- --- ------- scattered silt seams;scattered shell 12 fragments encountered about 50 feet bgs; (HaD) SP-SM/SM. ,s= 35 -0--——-------- i 40 14 45 15 � I 50 U -. . . . . . . . -- m l � ---0----i . al ,6I x BOTTOM OF BORING 51 5 . . . . . . . . ! . . . . . . . . . COMPLETED 7/28/2003 I LEGEND 0 20 40 60 ' Sample Not Recovered = Piezometer Screen and Sand Filter 40 %Water Content I Standard Penetration Test ® Bentonite-Cement Grout Plastic Limit (--40—I Liquid Limit 'o ® Bentonite Chips/Pellets Natural Water Content N ® Bentonite Grout 0 Ground Water Level ATD Strander Boulevard/SW 27th Street 1 Ground Water Level in Well w 3 Ground Water Level in VWP Improvements t- NOTES Renton and Tukwila,Washington a 1.The boring was performed using Mud Rotary drilling methods. m 2.The stratification lines represent the approximate boundaries between soil types,and the transition may begrat. LOG OF BORING B-106 MWNW � 3.The discussion in the textt of of this report is necessary for a proper understanding of the N nature of the subsurface materials. J 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 w 5.Refer to KEY for explanation of symbols,codes and definitions. A a 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON & WILSON A , INC. FIG. < Geotechnical and Environmental Consultants SOIL DESCRIPTION ti -6 a a -0 li Standard Penetration Resistance r E a n o L (140 Ib.weight, 30-inch drop) � o m A Blows per foot Surface Elevation:24.1 Ft. Datum: NAVD88 EL 0 20 40 60 Medium stiff,brown and light brown mottled,clayey SILT and loose,silty, fine to medium SAND; moist to wet; scattered 0.1 1I organics;numerous iron oxide stains ---------- 0{-------- between 5 and 6.5 feet below ground 0 2I surface b s ; HeD MUSM. 7.0 Very loose to loose, dark gray,slightly silty : 0.2 3I to silty,fine SAND;wet;trace of clay; (HaD) '.,. c 10 SP-SM/SM. 0.1 41 0 SIk Very soft to medium stiff, gray,slightly 14.5 15 --- -- --- ---- --Q---- 0 6� clayey to clayey SILT and silty CLAY;wet; scattered to numerous organics; (HeD) M UC L. 1 I 20 6 — —.__.-- ---------- ---0— Medium dense to dense, dark gray,trace to 22.5 9 slightly silty,fine to medium SAND;wet; scattered layers of soft, silty clay and silty, 10 25 -- ------ - fine sand; scattered organics; (HaD) SP SM. "I 30 --—- --!--0---- - --- 12 I 35 --- 13 I 1T 40 4 � . . -- 1 . . . . . . . � . . . . .15 . . J45 50 cc 16� I > . . . . . . . . . . . i . CONTINUED NEXT SHEET LEGEND 0 20 40 60 Sample Not Recovered SZ Ground Water Level ATD 0 %Water Content Standard Penetration Test .. Plastic Limit Liquid Limit II Thin wall Sample o Natural Water Content N I o Strander Boulevard/SW 27th Street Q. Improvements NOTES Renton and Tukwila,Washington a 1.The boring was performed using Mud Rotary drilling methods. m 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. OF NG LOG BORI B-107 4 t.7 r 1 Y t.7 I The discussion in the text of this report is necessary for a proper understanding of the N nature of the subsurface materials. 4.Groundwater level,it indicated above,is for the date specified and may vary-0 February 2004 21 1 09369 002 (rl w 5.Refer to KEY for explanation of symbols,codes and definitions. Cn 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON & WILSON, INC. FIG. 1�1-8 a Geotechnical and Environmental Consultants Sheet 1 of 3 SOIL DESCRIPTION u o E a li Standard Penetration Resistance E Q o Z6 r (140 lb.weight, 30-inch drop) o m 2 A Blows per foot Surface Elevation:24.1 Ft. Datum: NAVD88 p a U) p 0 20 40 60 n Medium dense to dense, dark gray, trace to 58.0 slightly silty,fine to medium SAND;wet; ` '" 60 ------- -- - ---- ------ ----- t eIlayers of soft, silty clay and silty fine sand; scattered organics; (HaC) SP-SM. ' 65 -- -- - --- — —®---- -- 19 I 70 20� 75 ----------- ---®------- -._. 21� i . T 80 ----- ----- -- 22 23I85 ---- ---- —® --- -------- zaI 90 —---- - Z. I I -- -- 2 � 95 5 —�— 100 -- 261 m Dense and very dense,dark gray, slightly 103.0 � rY 9 Y, 9 Y � . . . silty, gravelly SAND and slightly silty,sandy 105 ¢ —=— 271. I GRAVEL;wet; (Hag) SW-SM/GW-GM. I x . . . . . . . . . . . . � . . . . . . . CONTINUED NEXT SHEET 0 20 40 60 LEGEND Sample Not Recovered I Ground Water Level ATD 0 %Water Content = Standard Penetration Test Plastic Limit 1 --0 Liquid Limit o Ij Thin wall Sample Natural Water Content r` a o Strander Boulevard/SW 27th Street Q. Improvements rlorEs Renton and Tukwila,Washington a 1.The boring was performed using Mud Rotary drilling methods. m 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-107 0 3.The discussion in the text of this report is necessary for a proper understanding of the nature of the subsurface materials. 0 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 0 w 5.Refer to KEY for explanation of symbols,codes and definitions. 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON &WILSON, INC. FIG. A'H Geotechnical and Environmental Consultants � Sheet 2 of 3 SOIL DESCRIPTION o E a ti Standard Penetration Resistance L E a 0- s (140 lb.weight, 30-inch drop) o 2 � A Blows per foot Surface Elevation:24.1 Ft.Datum: NAVD88 p a O 0 20 40 60 29 29� 117.0 I . Medium dense to dense, gray,trace to slightly fine gravelly,fine sandy SILT grading to slightly fine sandy,silty CLAY 12030 O- — - --- --- below about 127 feet;wet;layers of silty, 1 fine sand;scattered organics; (HeC) j MUCL 125 ---- ....---- --Q 31� \--li, 130.5 130 ---------- -----Q Dense, gray,silty,fine SAND and fine 32I sand SILT;wet; HaC SM/ML. 133.0 Dense to very dense,gray,trace to slightly . . . . . silty,sandy GRAVEL;wet;broken rocks 135 --- Q- -- ------ -- -------- recovered;cobbles potentially present; 33 90 (Hag) GW-GM. j . . . . 34= 140 --Q----- -- ---50/4" i 35= 145 Q -Y I . . . . . 50/5"- 36=* 150 I . . . .-50/5" 152.0 . . . . . . . . . . . BOTTOM OF BORING . . . . . . . . . . . . . . o COMPLETED 7/31/2003 Y f 155 - NOTE: Boring lost drilling mud from about . . I . 140 to 152 feet below ground to surface. Boring was grouted to I circulate drilling mud. Boring was 160 --- --r-- - advanced to 152 feet where boring x was terminated due to very difficult m drilling and gravels caving. . . _ . LEGEND 0 20 40 60 Sample Not Recovered a Ground Water Level ATD Q %Water Content I Standard Penetration Test Plastic Limit 1-0—j Liquid Limit o IT Thin Wall Sample Natural Water Content n a o Strander Boulevard/SW 27th Street t, a Improvements LU t- NOTES Renton and Tukwila,Washington a 1.The boring was performed using Mud Rotary drilling methods. 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-107 3.The discussion in the text of this report is necessary for a proper understanding of the nature of the subsurface materials. p 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 w 5.Refer to KEY for explanation of symbols,codes and definitions. 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON & WILSON, INC. FIG. A-8 < Geotechnical and Environmental consultants Sheet 3 of 3 SOIL DESCRIPTION U_ o E t% Standard Penetration Resistance _ E a a o m s (140 lb.weight,30 inch drop) o M c7 Blows per foot Surface Elevation:23.2 Ft.Datum:NAVD88 0 a U) 0 0 20 40 60 Soft, brown to dark brown and gray, slightly clayey to clayey SILT and loose,silty,fine SAND; moist to wet;scattered organics and 0 tI numerous iron oxide staining; mottling in 5 — -- --- .__ __.-.-- .---- - -----—— sample S-1; (HeD) MUSM. 0 zI 0 3I •. . T 64 Very loose,dark gray, silty,fine SAND, 10.0 0 41 10 trace of clay; wet; HaD SM. 12.0 1 N Very soft to soft,dark gray and green-gray, 0 5I a N ~i clayey SILT and silty CLAY;wet;scattered 15 sa to numerous organics; (HeD) ML/CL. s - 0 7 19.0 • Medium dense,dark gray,trace to slightly 20 ____-_ _._____!__.__.__________ ._ _____—__ ss silty,fine to medium SAND;wet;scattered eI 21.3 s 117 - organics; HaD SP SM. o Very soft, dark brown, silty PEAT and peaty e SILT;wet- partings of silty,fine sand; (HeD 25.0 0 25 — ----- --------- --- �- 10 and H PT/OL. z Very loose,dark gray,slightly silty,fine • 11 O SAND and very soft,slightly fine sandy SILT, interlayered;wet; scattered organics; 30.0 T z 30 -- — ' HaD SM/ML. 121 . . . . . . Medium dense to dense, dark gray, clean to slightly silty,fine to medium SAND-wet; trace of coarse sand; occasional organics; 3513� (HaD) SP-SM. I . 40 -- —•—----- 1445 � . o Y n 15� l . . . . m . . . . . . Dense,dark gray,trace to slightly silty, fine 48.0 s to medium SAND;wet; (HaC) SP-SM. TT 50 --• - -- 2 161 x BOTTOM OF BORING 51.5 COMPLETED 7/31/2003 LEGEND 0 20 40 60 • Sample Not Recovered = Piezometer screen and Sand Filter • %Water Content I Standard Penetration Test ® Bentonite-Cement Grout Plastic Limit 1--0 Liquid Limit o TT Thin Wall Sample ® Bentonite Chips/Pellets Natural Water Content a ® Bentonite Grout o Ground Water Level in Well Strander Boulevard/SW 27th Street Z Ground Water Level in VWP CL Improvements NOTES Renton and Tukwila,Washington a 1.The boring was performed using Mud Rotary drilling methods. m 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-108 nA`A,n W 3.The discussion in the text of this report is necessary for a proper understanding of the �.7 f BORING v IVI Y1l/V YY N nature of the subsurface materials. N 0, 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 w 5.Refer to KEY for explanation of symbols,codes and definitions. 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON &WIL$ON, INC. FIG. A-9 Q Geotechnical and Environmental Consultants SOIL DESCRIPTION LL -0 0. Cn -o LL. Standard Penetration Resistance c E Q fl- o m � (140 lb.weight, 30-inch drop) n c o ro 2 3 ♦ Blows per foot Surface Elevation:23.3 Ft.Datum:NAVD88 O rn 0 20 40 60 Medium stiff, brown,clayey SILT; moist to wet;scattered organics; scattered iron oxide staining; (HeD) ML. ° tI Loose to very loose,brown to dark gray, 0 2I silty,fine SAND; moist to wet; layers of Q clayey silt and fine sandy silt; scattered 0 0I • organics;scattered iron oxide staining; 10 - -.. ---— 0' -- - (HaD) SM. 0 4I Very soft,gray and gray-green,clayey 12.0 o sI H 0 SILT;wet; layers of loose, slightly silty to silty,fine to medium sand; scattered s= 15 -------"- ----"--`"--- —O -- organics and peat lenses; (HeD) ML. 18.9 62 Medium stiff,brown and gray, silty PEAT 20 __ _____— __.____._____ 129 and clayey SILT;wet;partings of silty,fine a sand' HeD and H PT/ML. 22.0 Loose,dark gray to slightly green-gray, 91 silty,fine SAND and soft, clayey SILT;wet; 25 __...__—____---------- scattered organics; (HeD) MUSM. 10� 1 . . . . . Medium dense to dense,dark gray, slightly 27.0 silty,fine to medium SAND;wet;scattered i layers of organics; (HaD) SP-SM. T 3012 ---- ® ------------ tsI 35 -. . —®— - ----- --- 1 taI 40 0 ---- - --- -- - ------- ' x 45 --------- —0— ----- ,SI Very stiff,gray,trace to slightly fine sandy, 46.0 m silt CLAY;wet; HeD CL. 48.0 Loose to medium dense, dark gray, slightly silty,fine to medium SAND;wet;scattered 16� 50 -- - ----- -- layers of organics;scattered layers of m clayey silt;(HaC)SP-SM. g CONTINUED NEXT SHEET LEGEND 0 20 40 60 ' Sample Not Recovered 2 Ground Water Level ATD 0 %Water Content Z Standard Penetration Test Plastic Limit !-0 Liquid Limit o IT Thin Wall Sample Natural Water Content R a o Strander Boulevard/SW 27th Street Improvements Lu NOTES Renton and Tukwila, Washington a. 1.The boring was performed using Mud Rotary drilling methods. m 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-109 q 3.The discussion in the text of this report is necessary for a proper understanding of the a nature of the subsurface materials. p 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 (r: 5.Refer to KEY for explanation of symbols,codes and definitions. W SHANNON &WILSON, INC.I FIG. A-10 En 6.USCS designation is based on visual-manual classification and selected lab testing. Geocecnnicai and Environmental Consultants � Sheet 1 of 2 SOIL DESCRIPTION LL -6 EE a ILLStandard Penetration Resistance s E CL a a o ro r (140 lb.weight,30-inch drop) o M (D A Blows per foot Surface Elevation:23.3 Ft.Datum:NAVD88 0 a. U) 0 0 20 40 60 17 60 - - - --- - t6I 66.0 Dense to very dense, dark gray,clean to 2066.0 65 ---- •- ._� --" . � ' slightly silty,fine to medium SAND,trace of gravel;wet; scattered organics; scattered 70 ---- ------ -- -- .. - shell fragments in sample S-24; (HaC) 21I SP-SM/SP. 75 --------- - ------- --— ----- Flakes of ash. 22I 80 -- — �.-- -- 23 85 Flakes of ash. 24I I - i I 90 2s I i i 95 ------®— --- 261 63 Very dense, dark gray,gravelly SAND and 97.0v: . . . . . o sandy GRAVEL;wet;trace of silt; a. numerous shell fragments; Hb SP/GP. 100.5 27= 100 - BOTTOM OF BORING I z COMPLETED 8/1/2003 m — —---- - ------- U io 105 -- j i LEGEND 0 20 40 60 ' Sample Not Recovered Q Ground Water Level ATD • %Water Content I Standard Penetration Test o Thin wall Sample Plastic Limit F----*—� Liquid Limit P Natural Water Content a o Strander Boulevard/SW 27th Street 0 CL Improvements NOTES Renton and Tukwila,Washington a 1.The boring was performed using Mud Rotary drilling methods. rn 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG Q F BORING B-1 09 e 3.The discussion in the text of this report is necessary for a proper understanding of the l7 nature of the subsurface materials. ' p 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21 1 09369 002 5.Refer to KEY for explanation of symbols,codes and definitions. w SHANNON & WILSON, INC.I FIG. A-10 cn 6.USCS designation is based on visual-manual classification and selected lab testing. Geotechnical and Environmental Consultants � Sheet 2 of 2 SOIL DESCRIPTION LL o E a -0 LL Standard Penetration Resistance s E a n Z6 t (140 lb.weight, 30-inch drop) o E 2 C ♦ Blows per foot Cl) ccSurface Elevation:23.2 Ft.Datum: NAVD88 0 a• 0 0 20 40 60 Very loose to loose,brown, slightly clayey to clayey,fine sandy SILT; moist;scattered organics;scattered iron oxide staining o 1I ♦ O between 5 and 6.5 feet below ground 5 surface(bgs); scattered dark gray fine sand o zI . lenses; (HeD) ML. . . . . . . .®. I . . Very loose, dark gray,slightly silty to silty, 8'0 ° 3cc I . . . . . . . . . slightly clayey,fine SAND and fine sandy 0 10 _-__—_____—_ _ONP-________. SILT;wet; (HeD) SP-SM/ML. o aI os 15 --------- -- —_ —.—_._ — Very soft to soft,gray,slightly clayey,fine 16.5 ' . . . . . . . . . 154 ; . . . . . . . . I . . . . . . . sandy SILT and silty CLAY with layers of 'I I � slightly silty,fine sand;wet; layers of silty, 20 clayey peat between 17.5 and 19 feet bgs; a �, . . . . . scattered to numerous organics; (HeD) 9 MUCUOL O . Medium dense to dense, dark gray,slightly 24 7 �o 25 `-- �------ ---— silty,fine to medium SAND,trace of coarse sand and fine gravel;wet; scattered lenses „I of slightly clayey silt;scattered to numerous organics and wood fragments; (HaD) 12 30 ! O SP-SM. 13 35 I . . . . . 40 ------ ---+4 ,aI : : : . Dense, dark gray, slightly silty,fine to 43.0 w medium SAND, trace of coarse sand;wet; 45 scattered to numerous organics and wood ts� fragments; scattered shell fragments d between 50 and 51.5 feet bgs; (HaC) j SP-SM. ,sI 50 . . . . . . . . . x BOTTOM OF BORING 51.5 o COMPLETED 8/4/2003 . . . . . . . . . . . . . . . . . . . . . . . . LEGEND 0 20 40 60 ' Sample Not Recovered Piezometer Screen and Sand Filter O %Water Content I Standard Penetration Test ® Bentonite-Cement Grout Thin wall Sample Plastic Limit f---O---� Liquid Limit o p ® Bentonite Chips/Pellets Natural Water Content a ® Bentonite Grout o Ground Water Level ATD Strander Boulevard/SW 27th Street 1 Ground Water Level in Well Improvements Uj NOTES Renton and Tukwila,Washington a 1.The boring was performed using Mud Rotary drilling methods. aa,, 2.The stratification lines represent the approximate boundaries between soil types,and the transition may begradual. 0 LOG OF BORING B-110 MW 3.The discussion in the text of this report is necessary for a proper understanding of the nature of the subsurface materials. °p 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 w 5.Refer to KEY for explanation of symbols,codes and definitions. N 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON 8r WILSON, INC. FIG. A-11 ¢ Geotechnical and Environmental Consultants 1mi SOIL DESCRIPTION o E a a u.. Standard Penetration Resistance s E a a o r (140 lb.weight, 30-inch drop) Cl) o m 0 0 A Blows per foot Surface Elevation:22.4 Ft.Datum:NAVD88 0 FL Cn 0 0 20 40 60 Loose, brown,fine sandy, slightly clayey to clayey SILT,trace of coarse sand; moist; ' scattered organics; scattered iron oxide 0 lI O stainin HeD ML. 4.5 5 — Loose to very loose, gray,slightly silty to :: . 0 21 silty, fine SAND and fine sandy,clayey ' 0 3 c . SILT; moist to wet; scattered iron oxide �-• o staining between 5 and 9 feet below ground 10 --- --- --- --- 0--- -- surface (bgs);scattered organics- (HeD) ° 41 o SP-SM/SM/ML. 12.0 O Loose to medium dense, dark gray, slightly 5I silty,fine SAND;wet; (HaD) SP SM. 15 - —- --- --------0-- -------- 0 aI 1 7z Loose to medium dense, dark gray,slightly 19.5 eI 20 ----- ----' --- - -- -- -O- silty to silty,fine SAND;wet; scattered seams and layers of clayey silt;scattered to O s numerous organics and wood fragments; approximately 5-to 7-inch-diameter logs 10 25 - ---- ---i---- ------ -.-_ ...-__ 1 3 between 22.5 and 26.5 feet bgs;trace of coarse sand between 30 and 31.5 feet bgs; (HaD)SP-SM/SM. l . . . . . . . 30 - - -- -- - --------------O.-- 12 BOTTOM OF BORING 31.5 COMPLETED 8/4/2003 35 40 w 45 m j . s 50 J LEGEND 0 20 40 60 • Sample Not Recovered 2 Ground Water Level ATD O %Water Content Z Standard Penetration Test Plastic Limit f 0 Liquid Limit o Natural Water Content N o Strander Boulevard/SW 27th Street Improvements F NOTES Renton and Tukwila,Washington 'a 1.The boring was performed using Mud Rotary drilling methods. m 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-111 3.The discussion in the text of this report is necessary for a proper understanding of the nature of the subsurface materials. 0 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 w 5.Refer to KEY for explanation of symbols,codes and definitions. N 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON 8r WIL$ON, INC. FIG. Q-12 ¢ Geotechnical and Environmental Consultants - SOIL DESCRIPTION LL o E _ li Standard Penetration Resistance s E a o 6 -E (140 lb.weight,30-inch drop) a rn o M 0 � � A Blows per foot Surface Elevation:23.3 Ft.Datum:NAVD88 p FL U) p 0 20 40 60 Loose,brown, slightly clayey,fine sandy SILT; moist;trace of fine gravel; scattered ' organics;scattered iron oxide staining; soil 1 1 description based on soil cuttings; (HeD) 5 ML. 2 7.0 Interbedded, soft,gray,clayey SILT and Q very loose,silty,fine SAND; moist to wet; o sI a scattered organics;scattered iron oxide o 10 -------- -- -® -------- 0 4= m . . . . . . . � . . staining; HeD MUSM. 12.0 I Very soft to medium stiff, gray,clayey SILT; 0 5T 1 wet;trace of fine sand; scattered to �L I -- ----——r r numerous organics and wood fragments; 15 o layers of silty clay;layers of peat between 82 17.5 and 21.5 feet below ground surface 7I i . . . . . . : . . . . . . . . . : . (bgs); grading to clayey,fine sandy silt 20 117 below about 22 feet; (HeD) ML/OL. s= 81 9 Medium dense,dark gray,silty,fine SAND; 24.5 - - 25 — --- wet;scattered lenses of clayey silt; (HaD) 26.5 SM. i . . . . . . . BOTTOM OF BORING . . . . . . . . COMPLETED 8/5/2003 30 -----35 — i 40 i : i . . — o —— . . . ------ -- — Y 45 I � . . . . U50 x . . . . . . . . . . . . I . . . . . . . . . . . . . . � . . . . . . . . . I LEGEND 0 20 40 60 * Sample Not Recovered I Ground Water Level ATD %Water Content I Standard Penetration Test Plastic Limit 1—0 - I Liquid Limit e Natural Water Content a o Strander Boulevard/SW 27th Street Improvements LU NOTES Renton and Tukwila,Washington a 1.The boring was performed using Mud Rotary drilling methods. m 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B�� 12 3.The discussion in the text of this report is necessary for a proper understanding of the N nature of the subsurface materials. 0 0 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1 09369 002 w 5.Refer to KEY for explanation of symbols,codes and definitions. Cn 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON & WILSON, INC. FIG. A-13 < Geotechnical and Environmental Consultants U_ a o ti Standard Penetration Resistance SOIL DESCRIPTION o f _ L E a a o � L (140 lb.weight, 30-inch drop) o A Blows per foot Surface Elevation:Approx. 19.0 Ft. Datum:NAVD88 o n to 0 0 20 40 60 Stiff to soft, brown-gray,trace to slightly sandy, clayey SILT and silty CLAY; moist; ' layers of medium dense, slightly silty, ° 1_ j gravelly sand between 3.8 and 5 feet; 5 __- ____ ._.--.-. _____ �._o.__ scattered to numerous organics and wood ° z= I fragments;scattered iron oxide staining; 7.0 T 122 HeD MUCL. ° 31 . . ea Very soft to medium stiff,gray, clayey SILT; TT 10 — --- - -----. ------- — moist to wet;trace of fine sand; scattered ° ° f_ 1 . Lumerous clayey peat;scattered to 12.0 S? organics and wood fragments; e . o H/OH. 15 ----— --- ----O ---- — Very loose to medium dense, dark gray, o sI o trace to slightly silty,fine SAND;wet; 7� . . . . . . :.' scattered lenses of clayey silt;scattered 19.5 or anics; HaD SP/SP SM. 20 — --- — ----- -------- Medium dense to dense, dark gray,fine to medium SAND;wet;trace of silt; grades to eI trace of coarse sand with depth; (HaD) SP. 25 ------ 10 BOTTOM OF BORING 26.5 . . . . _ . . . , . . . . . COMPLETED 8/5/2003 j ' 30 --- --- --------- ------ 35 ' 40 ------- i . . -- i . ' 45 --------- - --- . . . . . . i . .------ 50 -------- ---. . . -----. . . .--- J LEGEND 0 20 40 60 • Sample Not Recovered Ground Water Level ATD 0 %Water Content I Standard Penetration Test Plastic Limit 1--0 Liquid Limit o Natural Water Content a o Strander Boulevard/SW 27th Street Improvements F NOTES Renton and Tukwila,Washington Q. 1.The boring was performed using Mud Rotary drilling methods. 2.The stratification lines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-201 3.The discussion in the text of this report is necessary for a proper understanding of the N nature of the subsurface materials. ' p 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21 1-09369 002 a: 5.Refer to KEY for explanation of symbols,codes and definitions. W SHANNON &WILSON INC. N 6.USCS designation is based on visual-manual classification and selected lab testing. Geotechnicai and Environmental Consultants FIG. A-14 ' SOIL DESCRIPTION u o f m UL Standard Penetration Resistance E a a o r (140 lb.weight, 30-inch drop) a o E 2 � � A Blows per foot ' Surface Elevation:Approx.20.0 Ft.Datum: NAVD88 p a 0 20 40 60 M p Very dense, brown and gray,slightly silty to silty, gravelly SAND; moist to wet; scattered iron oxide staining; (Hf) SM. 0 1I • 90/11" 5 --- -- . 7.0 rStiff to soft,gray,silty CLAY;wet; Q numerous lenses of peat; scattered to 31. numerous organics and wood fragments; 0 10 - ------- ____ (HeD)COOL. 41' s 0 73 o sI 15 — 72 Medium dense to dense,dark gray, 17.0 7� tracesilty to silty,fine to medium SAND; wet; layers of fine sandy silt;grades to fine 20 -------- '---- --— --- I to coarse sand with depth; (HaD) SP/SM. i 9I 25 --—---- —�— -- ------- 10 BOTTOM OF BORING 26.5 I . COMPLETED 8/5/2003 . . . . . . . . . . . 30 —------- -------- ---- 35 -- . . . . . . . . .. . . . . . . . . . . . . . . . 1 40 ---- I I -- I r 45 -----'�------- . . . . . . U . . . . . . 50 J t LEGEND 0 20 40 60 Sample Not Recovered g Ground Water Level ATD • %Water Content I Standard Penetration Test Plastic Limit I--♦—I Liquid Limit Natural Water Content a ' a Strander Boulevard/SW 27th Street a Improvements w w NOTES Renton and Tukwila,Washington a 1.The boring was performed using Mud Rotary drilling methods. ' m 2.The stratification lines represent the approximate boundaries between soil types,and ao the transition may be gradual. LOG OF BORING B-202 3.The discussion in the text of this report is necessary for a proper understanding of the N nature of the subsurface materials. ' 0 4.Groundwater level,if indicated above,is for the date specified and may vary. February 2004 21-1-09369-002 w 5.Refer to KEY for explanation of symbols,codes and definitions. a6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON &WILSON, INC. FIG. A-1 cJ Geotechnical and Environmental Consultants FA RITrENHOUSE-ZEMAN 6 ASSOC., INC. BORING NuMeEA B-1 (continu(td) W.O. W-5263 . Ceoteclutical/Ilydrogeological Consultants PROJECT NAME Tukwila Jack in the Box 1 i STANDARD PENETRATION RESISTANCE ' SOIL DESCRIPTION 7 cr A BLOWS PER FOOT w to < 2 i (140 lb.hemmer,30 Inch drop) Ground Surface Elevation Approxlmetsy Feet 40 5 at 5 30 10 20 30 40 50 60 70 80 g0 100 Medium dense to dense, saturated, dark gray, _ fine to coarse SAND —— "-- — ' Total Depth 44 feet 45 -- C pate 22 June 1907 -50 55 - - - - -- 60 -65 < 70 Cn 04 th 75 R coo BO 4 SAMPLING GROUND WATER LABORATORY TESTS ' 'e 1 2'OD SPLIT SPOON SAMPLE SEAL X WATER CONTENT 911 3'OD SHELBY SAMPLE DATE m 9 25'10 RING SAMPLE WATER LEVEL NP NON PLASTIC c B BULK SAMPLE AT TIME OF DRILLING LIQUID LIMIT o OBSERVATION "--NATURAL WATER 9 A SAMPLE NOT RECOVERED WELL TIP CONTENT ' PLASTIC LIMIT Strander Boulevard/SW 27th Street $ Improvements Renton and Tukwila, Washington 0 LOG OF BORING B-301 o October 2003 21-1-09369-002 m SHANNON&WILSON,INC. I FIG. A-19 ' ti Geotechnkal and Environmental Consultants Shee(2 Of 2 ' TEST DATA BORING 16 a ' k a'a �^ t as " DPSCR=ON w 7• l C a Group 3 4 a o\ tip �,a a Symbol Surface Plc Lion(ft):� J L 0 Z U 0,,, mU n1 / Lntcrbcddca the sandy silt and sdry fmc Land with roots sot, 0 SM lootc,moist) MD 33 73 3 1 5 MZ Gray silt.ith fine sand(very soft to Loft,w Q 5 ' 2 10 j( 1 t ' 15 to W Li ML Gray silt with lenses of peat(soft,wer) z MD 64 61. 3 C. 0 20 20 4 Gndu to-ith lea of fnc sand 25 25 SP Black fine to medium sand(medium dense,wet) 29 30 30 U h MD 24 101 31 Q 35 35 9 4 0 m 40 40 Note:See Figure A-2 for explanation of Lymbols a ' to Log of Boring Geo t$o:Engineers Figure A-34 co Strander Boulevard/SW 27th Street Improvements m Renton and Tukwila, Washington 0 LOG OF BORING B-302 o October 2003 21-1-09369-002 m SHANNON &WILSON, INC. FIG. A-20 Geotechnical and Environmental Consultants Sheet 1 of 2 ' TFSrDATA BORING 16 (Continued) ■ L 7 ■ ' l'- aid 4— t y --•i DESCRIPTION M -■iC•� 7Cu o] E Group • 00\ t.•a -�03 0 • Symbol 44) 4 14 45 4 SP— Gny Ciao sand with silt and a trace of organic matter(medium 12 , SM dense,wet) 50 5( ' MD 27 tot 20 5 55 55 F to W U. sZi 12 ® Grades to sand with shell fragments H a Ot'j 60 MLA Gray fine candy silt to silty Cute sand(medium stiff,loan,wet) 60 SM 6 � 65 SM Gray silty fine sand(medium dense,wet) 6$ 22 i ' 70 SP— Gray fuze Land with silt(dense,wet) 70 QU : SM N ' 0 79 Boring completed at 73.5 feet o0 12/6/90 Ground.eater encountered at spproximately 6 feet during drilling 75 ,., 7S g 9 R 0 m o °D 80 Note:See Figure A-2 for explanation of symbols 80 a! tD ' 0 .����. Log of Boring $ GeO N Engineers Figure A-35 4 Strander Boulevard/SW 27th Street 4 Improvements to Renton and Tukwila, Washington 0 V LOG OF BORING B-302 o October 2003 21-1-09369-002 m SHANNON&WILSON, INC. I FIG. A-20 Geotechnical and Environmental Consultants Sheet 2 of 2 LL BORING No. Logged By srl. ELEV. Date -Q-B� us (N) aph Gr Soil Description �� Sample glow%CS i%} Ft. Tan ND cod �+- Tan gravelly silty SA vlth scattered = 38 9 sm cobbles, dry 5 6 18 Moist below 1', gray below 2.5' = qu-1.0tsf Brownish-gray organic SILT, moist, = 3 85 L.L-(,a 9 Y 9 oh medium stiff 10 IfPPUSH48 PI_ 6 123 Interbedded with peat 11' to 14' PUSH 252 15 42 ' Q T 16 29 ml- Interbedded gray clayey SILT and black 20 sm silty SAND, wet, medium dense 16 28 25 ____________ l Gray SILT, non-plastic, dense, wet, = 5 34 3' layer clayey SILT @ 28.5' 30 - . = 12 23 . J� j # Grayish-black silty fine to medium 35 I SAND, wet, medium dense It sm = 17 24 F With shell frag»ents below 37.5' 40 21 21 Boring terminated at 44 feet below existing grade. Groundwater encountered at 17 feet during drilling. Boring backfilled with cuttings. U Q 0 9 4 s.n...bc.m.u.a.Mae i....n..n.....w.r...1....n.hrsM r w.wrT•r....r.a w.�vti«H ra Mrrra rr.. m pep.•+.�I.Tay w M ti.... V MM Va MA W.""no V,r.►fYF••of r.+.r•do O .+�..u�n ..war.a.Y.•wo BORING LOG PROPOSED WAREHOUSE o RENTON, WASHINGTON In Z1 ` o corl I11Zi2Yu ZIIC. 4 GEOTECHNICAL ENGINEERING • GEOLOGY P%oj.No. 3453 Ds" July'87 PIs2e 5 m Co Strander Boulevard /SW 27th Street $ Improvements Renton and Tukwila, Washington 0 LOG OF BORING B-303 October 2003 21-1-09369-002 0 SHANNON &WILSON, INc. FIG. A-21 _m Geotechnlcal and Environmental Consuttanfs Logged By STI. BORING NO. A Date 7-7-87 ELEV. -S" GrtphC"SS Soil Description J 01) SamFle $l(N)owl N Ft 1/2' topsoil SW- Gray gravelly SAND with scattered = 48 7 SM cobbles, moist, dense (fill) 5 = 26 14 PUSH 225 ml Brownish-gray clayey SILT with scattered 10 IE POSH 225 organic matter, moist, soft __11LL LL-46 7T PUSH 54 PI- 8 Gray sandy SILT, wet, loose 15 jj = 23 35 4 am B1acJcf fins SMM, trot, +me6AUM dense 20 -t;—riyyM=brz5wn r"gray interlayered clayey 8 53 qu-0.25tsf organic silt t Land, wet, very soft CC Black fine. to mediumAN SD, wet, medium am 2 dense 0 28 30 3 24 sm_ Gray cl!y!y SA_ND1 wet, very soft, with scattered gravel 35 Gray silty SAND with shell fragments, = 14 21 s" wet, median dense 40 i _ T 16 22 Boring terminated at 44 feet below existinq grade. Groundwater encountered at 9.5 feet during drilling. 1" PVC standpipe installed to bottom of boring. Lower 10 feet slotted- Boring backfilled with cuttings. a Water level on 7-9-87 was 6.8 feet. `n • Vertical datum unknow:j. Elevations determ!ned with respect to a $ temporary bench mask, the top of the n:.rth side of Southwest 27th Street, at an assumed elevation, a,`. C.0 feet. 89 w carry"M yr�r�+r�+;wW w '1 �+••.w Mw^-+T."r.Ne.o.:r.y wwY..w*...,rw—i M --o-'wsw.M.I rr r-w w—Pow—A~9 IF, BORING LOG a PROPOSED WAREHOUSE ob + y RE2�TON, WhSHIHGION 0 Consultantz In6. 1 }1 m GLOTLCNNICAL CNGINE"ING!GCOLOGY Pro],No. 3453 date July'87 Plate 4 9 Q Strander Boulevard/SW 27th Street 4 Improvements Renton and Tukwila, Washington 0 LOG OF BORING B-304 9 October 2003 21-1-09369-002 SH ANNaON Wl and mentalcor INC.Geots FIG. A-22 LL Test Pit Log Project Name: Sheet of S.W.2TrH Street Warehouse 1 1 Job No. Logged by. Date: Test Pit No.: 3453-4 1 DSL 8 3 94 TP-1 Excavation Contactor: Ground Surface Elevation: Evans Brothers Construction t Notes: u� L v N o Surface Conditions: Grass %) A N tL N 7 7r t (n U) rn SM FILL, &own silty fine to coarse SAND with gravel,medium dense,moist 1 SP-SM FILL- Down poorly graded medium to coarse SAND with silt and gravel,medium dense 2 Al..4 3 4 FILL- Gray poorly graded medium to coarse SAND with silt 15.6 5 6 -slight caving 7 8 very minor seepage — — PEAT Dark brown fibrous PEAT interbedded with organic sift,soft to medium stiff,wet to L L saturated 91.1 `.A ILL 9 10 t 1 46.E ML Gray SILT,soft to medium stiff,saturated 12 13 14 Test pit terminated at 14 feet below existing grade. Very minor groundwater seepage U encountered at 8 feet during excavation. N o Q M o 4 a m o m t, Test Pit Log Earth i ConsWf�ts Inc. S.W.2TTH Street Warehouse a M °�°'° "'a°"�Oia1Op""m`° ''""'"" Renton,Washington w -1 Prof.No. 3453-4 Dim. GLS Date AUg'94 Checked DSL Date 8/17/94 Plate A2 o Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering testa, 4 analysis and judgment. They are not neoesaarily representative of other times and locations.We cannot accept responsibility for the use or m Interpretation by others of Information presented on this log. 4 Strander Boulevard /SW 27th Street C, Improvements Renton and Tukwila, Washington Co m LOG OF TEST PIT TP-301 October 2003 21-1-09369-002 0 _ SHANNON 8r WILSON, INC. FIG. A-23 m Geotechnical and Environmental Consultants ii Test Pit Log Project Name: Sheet of S.W.27TH Street Warehouse 1 1 Job No. Logged by. Date: Test Pit No.: 3453-4 DSL 8 3 94 TP-13 Excavation Contactor. Ground Surface Elevation: Evans Brothers Construction f Notes: W =0 } (n Surface Conditions: Grass (%) ro 0. T 13 adil}i m j L N to N SM F1l1_ &own silty SAND with gravel,medium dense,damp 1 SPSM 11LLL Brown poorly graded SAND with silt and gravel,medium dense,damp 3.9 2 3 4 -becomes wet 5 RLL: Gray poorly graded SAND with silt 10.1 6 7 8 45.8 = — PEAT {minor seepage 9 &own fibrous/woody PEAT interbedded with organic silt,very soft to soft,saturated L 102.3 10 11 MH Gray elastic SILT,soft to medium stiff,saturated 43.3 qu=1.25-1.Sts} 12 4&5 13 qu<.5tsf 14 Test pit terminated at 14 feet below existing grade.Minor groundwater seepage U encountered at 8.5 feet during excavation. N o Q 0 0 u5 4 a m a m Test Pit Log Earth Consu1tantS Inc. S-W.27TH Street Warehouse G-ftc "W4.°""°°`°`""o Renton,Washington a F H Prof•fJo. 3453� Dwn. GLS Date Aug'94 Checked DSL Date 6/17/94 Plate A14 o Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, q anatysls and judgment They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or a) Interpretation by others of Information presented on this log. i Strander Boulevard / SW 27th Street 4 Improvements to Renton and Tukwila, Washington al 0 LOG OF TEST PIT TP-302 October 2003 21-1-09369-002 0 SHAANNON�vWInLSO N,SINC. FIG. A-24 Test Pit Log Project iJams: Sheet of S.W.27TH Street Warehouse 1 1 Job No. Logged by. Date; Test Pit No.: 3453-4 DSL 8 3 94 TP-2 Excavation Contactor. Ground Surface Eevation: Evans Brothers Construction t Notes: o_ m o Surface Conditions: Grass %) m a .1ii L N O Cl) N SP-SM FILL-Brown poorly graded medium to coarse SAND with silt and gravel,medium dense, moist 1 4.7 2 3 4 13.6 5 6 7 - minorsaepage — — 8 PEAT Dark brown fibrous PEAT Interbedded with organic silt,soft to medium 108.2 stiff,wet to saturated u u g S 10 — 11 12 ML Gray SILT,soft to medium stiff,saturated 512 13 14 U Q 15 rn Test pit terminated at 15 feet below existing grade. Minor groundwater seepage encountered at 7.5 feet during excavation. Cl) 0 9 r Q .1 P 0 of �' co O Test Pit Log Earth Consultants Inc. S.W.27TH Street Warehouse °'°'*"'Ce1**V G.M.°"a'°`°°m"r''a""""' Renton,Washington a ~ F Pre.No. 3453 Dn. GLS Date Aug'94 Checked DSL Data 8/17/94 jPlat. A3 0 Subsurface condltlons delpicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, 4 analysts and judgment. They are not nscessarlty representative of other times and locations.We cannot accept responsibility for the use or 0) Interpretation by others of Information presented on this log. 4 Strander Boulevard /SW 27th Street Improvements a) Renton and Tukwila, Washington a LOG OF TEST PIT TP-303 October 2003 21-1-09369-002 0 SHANNON &WILSON, INC. FIG. A-25 m Geotechnk�l end Environmental Consultants DRILLING COMPANY: Holocene LOCATION: See Figure 2 DRILLING METHOD: HSA,split spoon sampler DATE COMPLETED: 4/27/98 SURFACE ELEVATION: 20 t Feet LOGGED BY: MB N W h uj U_ tL w m Z S - _ a tandard Penetration Resistance U 2 G r _ w_ z in c w 3 (140 lb.weight,30'drop) m O w w N I O A Blows per foot = m rn d cc H w j F=- f 2 z o M O a. p in ¢ DESCRIPTION in N in Q..- O c7 0 0 10 20 30 40 50 0 0 SM Loose to medium dense,dark yellowish brown, slightly gravelly,silty SAND,moist. Fine to coarse sand. Fine to coarse subrounded gravel.Trace organics,grass,roots. S t 7.7-7 (FILL) ! - 5 _............;............_............i- S-2 3.4-5 w OH Medium stiff,very dark brown,ORGANIC SILT, I 10 moist. Contains organics,peat,reeds,leaves. ............ ............_ _ _ _ 10 i/ 1 z �53 123 — I ?> ............ ......1.....-: i/ SZ SM Loose to medium dense,dark grayish brown, S-4 2-2-4 silty SAND,moist to wet. Fine to medium sand.Trace organics,grass. 20 ,......:......_......,...... ..._....... ......I 0 (ALLUVIUM) i i ML Soft to stiff,very dark grayish brown,very S•5 6-2.9 GS sandy SILT,moist to wet. Fine to medium sand. ` :. 25 _ - - 5.... 2 At 27.5 feet grades to very stiff SILT with S-6 5-11-13 trace of fine sand. Contains trace fibrous organics matter. _ 0 3 0 ......:......,............ ......' s V) ♦' At 32.5 feet grades to dark gray,sandy SILT, S•7 2.2-1 G wet. Fine sand.Trace shells in sampler tip. ` 3 5 ..... ...... ..... ... - - - 5 3 r g SM Medium dense to dense dark gray,silty SAND, P S•8 2-6-10 GS 9 4 wet. Fine to medium sand. Trace organics, wood fragments. E 40 0 0 20 40 60 BO 100 40 Water Content(%) Plastic Limit f—0 Liquid Limit Natural Water Content NOTE:.This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. Ci 0 '' SW 27th Street Culvert Replacement BORING: BH-2 HMGEOSCIENCES INC Renton, Washington PAGE: 1 of 2 4 Strander Boulevard/SW 27th Street 4 Improvements Renton and Tukwila, Washington 0 LOG OF BORING B-305 c October 2003 21-1-09369-002 Lo SHANNON &WILSON,INC. FIG. A-26 m Geotechnkal and Environmental Consultants Sheet 1 of 2 LL FDRILLINGNY: Holocene LOCATION: See Figure 2 D: HSA,split spoon sampler DATE COMPLETED: 4/27/98 TION: 20 3 Feet LOGGED BY: MB U ww 2 Q L F H Standard Penetration Resistance m > z y c 3 (140 lb.weight,30"drop) o = O 0 W J w m Z ♦ Blows per foot `J _ a F- m Or Q 3 W Zo 2 O a Lu 0 N ¢ DESCRIPTION of y w o cc 40 0 10 20 30 40 50 40 SP Medium dense to very dense,dark gray,fine to S-9 13.14-14 coarse SAND,wet. Some shell fragments. _ _ 45 45 .....-_............ ...... ..... ........... �S-10 12-12-16 ' ♦' 50 : ..... ............. - -50 S-11 15-23-29 • 55 : ...... ......'..-..._..-................'. - 5 �S-12 9-15-20 60 End of borehole at 59.0 feet. ""'- 6 Groundwater seepage encountered at 17.5 feet at time of boring. 65 ............_......`......' i E i i ..." - _ 65 70 ...... ...................i 7 U Q o - - 75 Q75 _.._ .... ...........'.__2...... rn g 4 m BO 80 0 20 40 60 BO 100 A Water Content(%) Plastic Limit 1—0 Liquid Limit Natural Water Content tM NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. 0 N `` SW 27th Street Culvert ReplacementID BORING: BH-2 Y 11L�1 HWAGEosmNcs ING Renton, Washington PAGE: 2 or 2 4 Strander Boulevard /SW 27th Street 4 Improvements Renton and Tukwila, Washington 0 LOG OF BORING B-305 e October 2003 21-1-09369-002 SHANNON &WILSON,INC. I FIG. A-26 m Geotechnkal and Environmental Consultants Sheet 2 of 2 �i ii DRILLING COMPANY: Holocene LOCATION: See Figure 2 DRILLING METHOD: HSA,split spoon sampler DATE COMPLETED: 4/27198 SURFACE ELEVATION: 21 t Feet LOGGED BY: MB fn w to U ¢ a U uJ <r H Standard Penetration Resistance o Z N w 3 040 lb.weight,30"drop) JO N w J w Z � Blows per foot x� CL � Z o ur O F- x o ~ p < ¢ ¢ w- 0 a W uYi DESCRIPTION rn y a� c7 ❑ 0 0 10 20 30 40 50 7"asphalt concrete. 0 SM Medium dense to very dense,dark yellowish brown,slightly gravelly,silty SAND,moist. > Fine to coarse sand.Fine to coarse,angular to S-t 16.28.28 subrounded gravel. 5 (FILU ......_................_ - - 5 Dark brown silt containing organic matter in the sampler tip. S-2 13.17.E OH Soft,very dark borwn,ORGANIC SILT,moist. i ......i...... 10 Contains organics,wood,leaves,reeds. 10 S•3 1-1.2 A' SM Loose to medium dense,dark grayish brown to S a 2.7.70 ' very dark brown,silty SAND,wet.Fine to medium sand. s 20 ......_......s..... - 20 (ALLUVIUM) S-5 2-5.5 i 25 ...... ..... ....:. -- -- - 25 s.. .` ML Very stiff,dark gray,sandy SILT,wet Fine S-6 7.14.14 %F A sand. E - - U SM Loose to dense,very dark gray,silty SAND, S•7 4-4-3 %F wet. Fine to coarse sand. Contains.silty € i - - layers, ¢ 35 ...... ................. ..._. ..... ....?......t 35 r7 i g • 5.8 3-8.10 4 40 ------------------------- 40 0 20 40 60 80 100 p Water Content M Plastic limit 1-0 Liquid Limit Natural Water Content NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated n and therefore may not necessarily be Indicative of other times and/or locations. 4 SW 27th Street Culvert Replacement BORING: 131-1-1 HMGEOSCIENCE$INC Renton, Washington PAGE: 1 of 2 Strander Boulevard/SW 27th Street $ Improvements Renton and Tukwila, Washington Cq LOG OF BORING B-306 e October 2003 21-1-09369-002 mSHANNON&WILSON, INC. FIG. A-27 LL Gaotachnkal and Environmental Consultants Sheet 1 of 2 F NY: HoloceneLOCATION: See Figure 2 D: HSA,split spoon sampler DATE COMPLETED: 4/27/98 ION: 21 t FeetLOGGED BY: MB wt w U— rt v u 0- LU '2 L F Standard Penetration Resistance _ > O w 3 (140 lb.weight,30'drop) J O w w w F- O • Blows per foot h = m 2 2 cc Z o W =( FZ- w p (n ¢ DESCRIPTION v) cn o_— O t7 0 10 20 30 40 50 O 40 40 SP Medium dense to dense,dark gray,fine to medium SAND. S-9 11-11.13 GS 45 Encountered some shells. -;- - - - 45 �S-10 8-11-11 • i 5 �S-11 10-18.20 • ♦' 55 ...... ............ ......':......'_ - 5 5 S-12 6-7-5 •dk ...... .................. - - 0 6 60 End of borehole at 59.0 feet. Groundwater seepage observed at 17.5 feet at time of boring. ......:...... ---..f...... 6 65 _...._...... ......'. ......`: 7 70 o .........................i - 7 5 .....` ...... Q 75 eo g 4 80 80 0 20 40 60 80 100 m m Water Content M Plastic Limit I—♦— Liquid Limit Natural Water Content NOTE: This log of subsurface conditions applies only at the specified location and on the data indicated y and therefore may not necessarily ba indicative of other times endlor bcationS. m BORING: BH-1 goo SW 27th Street Culvert Replacement HWAGEOSCIENCES INC Renton, Washington PAGE: 2 of 2 4 - .. Strander Boulevard /SW 27th Street Improvements Renton and Tukwila, Washington CD LOG OF BORING B-306 c October 2003 21-1-09369-002 SHANNON&WILSON,INC. FIG. A-27 m Geotachnical and Environmental Consultants Sheet 2 of 2 LAI-15 SAMPLE DATA SOIL PROFILE GROUNDWATER $ c Drilling Method: Hollow-stem A rgwr p z n ari Ground Elevation(A): b ' ri D E. g lled Br. Cascade Drilling lor. � I CL B 3 1 t..tBM brown,Ma to Med-Nm IkNo WMh 3M true ss(loose.wct)(no o6u.me sheen) 2 — ATD 1 ei i a 6 Ml gown,e-ndy,SILT wkh wgenta(mwdkxn -- — t0 ■�f,matst) L 2 117 0 U � - G ge^^9 completed a 1122M _ Q1j TOW Deolh d Rorie-11.5 h. 4 m 8 o, Notet I.SvatfpnOhic mnracm arc based an 604d telterprcutlona and an eOpWMnue• � 2. Rderenae t0 4,e leaf e(101a rfport k rwrceet>tfy ter a pryer rarderstar�np a n+bsuAau wnd�ioro. , 2. Rde,b s01 C1acsafc20.n]yetarr and Kee fa fer exp{arAlkm of graphic&a0d i),Mbda. m° ConocoPhlHips-Renton04 Figure LANDAUTerTnlnal Log of Boring i Ai-15 a^�1 Msocucns Renton,Washington n Strander Boulevard /SW 27th Street Improvements Renton and Tukwila, Washington co LOG OF BORING B-307 October2003 21-1-09369-002 9 SHANNON &WILSON, INC. FIG. A-28 Geotechnlcal and Environmental Consultants LAI-12 SAMPLE DATA SOIL PROFILE GROUNDWATER m` a Odmng Method' Hal stem Auger ~ o N Ground ElavafSon(tt): i a E v Dgwd,By: Cascade OrflGnp Inc. o „ rang ti B a � 0 Gray,ally,Ina w 0 wim or"W (m 1w denw,wc8(no eder,m MMn) Am � 1, 26 o 6 a ML �rvrTt SILT rd0�trace sand and ON°f1V—'——'— 1seR rncdct) to U Q 0 5of9 ri i O1 o t2 7Ma Depth of&-r9.11.5 tL Q yy g 4 9 4 1-14 m � 19 $ 0 Noter. 1. btrnttRaphk oontadt�fi taxed On fiW�Wyte4a/fOnc and as tppeordmaY. 2. K-Femme b Wa last ut*ft MPOl Y e�str"for a X=cr lardentand4�a of*Acuf ad 3. Rd«b-$oi C,laat6a6on st'rtcm VWKeY hi+ra fa aWWAaqjCa of OrWOrs uw aymaus. ConomPhiMps-Renton Figure I cq Terminal Log of Boring LAM2LANDAU A_� A ASSOCIATES Renton,Washington Co L 4 Strander Boulevard /SW 27th Street g Improvements 4 Renton and Tukwila, Washington 0 LOG OF BORING B-308 October 2003 21-1-09369-002 a SHANNON &WILSON, INC- FIG. A-29 Geotanical and Environmental Con tants LAIA I tSAMPLE DATA SOIL PROrILE GROUNDWATER Prilliny Mettrod' Holtaw.stem Auger - pp �ctaJ z N rn Gmund Elevation(ft)* 6 E 'Y Q s Ork}ss1 By: Cascade Orilbn9 InC. p �m fL 0 6tt Gray.ahY.W so metwm 8AN5 WT 9mV .1 (r-dWm Ostw,.c1)(no ad-,a0 sM-) Probdrce wt7 �,. nronvmalt end ponareh stet Anlmnhe awps e r.1d1 diem—W. Gd,*&Je 40,PVC*CA t �tnp ATD 1 21 1! 0 10120 S♦nd Pad 6 ♦.IneN 6�vnefd. Sthe"t 40,PVC amM(0.0104"Vot a{za) e O ML �towL SILT.vihlrxe sand in'd oeyinln (sa+�leolsl) 7hnadee End-eo4 g 2 ai ♦ o Q 0 g 12 pore�p Carr®fa�ad 012tfIfJJ Total Depth or Boring It.f ti Q rn o 4 u m 0 NoIK. 1. Buatgr&Oir wma=in baud on flee kRmvr-;+Gana sna an appradlaute. 2, Rafermca b ins Scat of tHY sport i+++weary far a ProPar W rslamdiny of-&UMt4M w.mhs.o 9. Aq(-1o'Sai Cksdllasaerl Sycaem eve KW AD#re far eaptana5vn of pnepflim ane aymbak. Figure I CortocoPhIMps-Renton 7ermfna! Log of [AI-11LANDAU Renton, A VVashington 7 c ASSOCIATES Cn Strander Boulevard /SW 27th Street $ Improvements Renton and Tukwila, Washington 0 LOG OF BORING B-309 c October 2003 21-1-09369-002 0 SHANNON 8�WILSON, INC. FIG. A-30 m Geolec&nkxt and ErrvironmentaI Consultants LL LAI-10 FSAIMMIRIFnATA SOIL PROFILE GROUNDWATER D6 6rg Method- Hodavi-stem Auger DOW E K Z f-- Ground F1evallan(A)• � o p �rilkd By c—de of2LN Inc. 8 p rn d N a 0. (7 Z2 A - - SM Graff,e4ty,fina b madi-m L-' 1M VAh Drevel :• . (meOlvm danee.WC)(no DdDr,no sheen) { Protective well .�.• �� rrw%n**and awrrrn teal 13entorctr d+4a 44nch d(arttety, zdvcdcasing a IQ PVC weJ 2 4 ATO 1 at 24 10M 32M P*= B 4=»ddameln. Schedule ao,avC screen(o.olo4och slot tl:e) a Ml �rwr4 SIIT with 4xa sand and a4�s (eef1,e,okq Threaded E:td rap iD 4 d U Q o por{ng CampleMd D1/2W0J' 2 total Depth of Boring-11.5 IL Q m g : 4 s p to Ha(es 1, blrrfgraphe oofMauc at*1>ud on Rald inlnprela0ona end err appfmdrfrEa. 9 2 Refwnte t the wnd"x a thn to�.fleDeaaerY for■p to ton of r rpm-ww afao tdnDttloM. $ J. Refer lr'6.i Ctasrdioe+k+n ay N+Y�ipve ConocoPhiUips-Renton Figure N Terminal Log of L I-10o LANDAU A-1 6 ASS S Renton,Washington 9 4 Strander Boulevard /SW 27th Street Improvements Renton and Tukwila, Washington 0 LOG OF BORING B-310 to October 2003 21-1-09369-002 0 SHANNON &WILSON, INC. FIG. A-31 m Geolechnlcal and Environmental Consultants LAI-1 SAMPLE DATA SOIL PROFILE GROUNDWATER S p hdathod Hoe ow-clam Auger Ocfad E 77yt[( Ground e(evatlon(fp c V n �t � a c� Dtiikd By' Cascade Dtilllrtp Inc m a 1n a. } 0 f - SM CU id Proleve wdl i . ti rnonur"M snd ca+aatt feral aentonaa cNps 2 4-)nah dwmww, Lqm brown A"to mtCure&AM with 0t S OVaa 40,PVC voa and grivvi goose,moist)(no odor,no sf+uN 1 e2 1e 10 4 2 a2 +4 ] — 6 P Gray, n�to medivn SAriO wM Ortrvq (tea to ov6'um dared,w-t)(very 3001 202 SanO Pack ga caw -its odor.no sh"n) ATD 4."alartrtlor, . Schedule 40.PVC aarean(o.oto:rn sbt e u 22 a l.4ttl b,-wm vK4i,v,ob(std1,nroa (no T},r-seW r..d cap 4 12 24 0 odor.no shim) 10 Bonner Cenptrbd 0110=3 U Todl Vsvw of Gonna 10.a R- L' j12 Q C) rh 4 ® 14 m 0 � Notts 1. 57aF0�9)+k amtadf an Dead an hid gtyrprestlra¢and an a�padntm 2. Refer,nee*the tax!of tltia prf h neccz$ar1'IEr a proper umdentand+na to ulzur(tos ocnM—L 3. Rarer to-sof aats)t)ctoon 3riem wW Kerry h9"w For of yr"No and sr nbQt L o pure InConocoPhillips-Renton N a) 4LANDAUTerminal Log of LAM �_7 1�SSOCU�I�S Renton,Washington 9 4 Strander Boulevard /SW 27th Street o Improvements 4 Renton and Tukwila, Washington C rn LOG OF BORING B-311 October 2003 21-1-09369-002 9 SHANNON&WILSON, INC. FIG- A-32 m Geotechnical and Environmental Consultants ii LAI-2 5 WPLE DATA SOIL PROFILE GROUNDWATER c Drmn9 Method Delaff II S Ground E Edon(it)- 3 Z E c�i nulled Sy: Cascade Dal"Inc, _ N rn l h � s —SM Prokdieo wte i \ n>anuTwt and ooneTele.Dal 2 Sentonge dip. 44nch diameter, L4ht brohm fine ia medium SAND-Rh.Di mina 40,PVC wril am jr—j aee.a.Moist)(no odor,no aeh0 aharn) t ex �e 77.0 --. 2 12 Ds e3 e P G-1 tlrx b Marx wdh OraM e1 DO 0.0 (medum dwua b very dune.r Q(ne ATD o0or.no shaan) 2I12 Sand Vau a;ncn diarnator. schadule 40,PVC acreen(0.010-irxh.7at slto) e s 22 sw 0 o a &avm.SILT with roots(vcry aCA.=130(^o Tnnaa.r snd sP S a2 2e 0 odor.no ahean) 10 g Daring ComPletad QVCV03 U Tcto aft of sort n a l as IL O 12 Q gg 01) S Q � t� m CJ '.3 boles: L SEr�lpraa,tfie CGnU[S!aY!booed OP lcld 1rt0erpnte6pne and art ayQrtvsirnata. 2. Re*WMR to ft Wt of 0*MPOM It W"Ury ibf a PMW un4rnnnd4n of.ubstrfi0a mndltiana. $$ s.Raw is la Ctxsria(bn Systom end KW re"ksr xumionseon or wwplq o and rrmhols. m ConocoPhApz-Renton FQU� N Terminal Log Of LAI-2 A'� m LANDAU Renton,Washington ASSOMTES 4 Strander Boulevard/ SW 27th Street Improvements Renton and Tukwila, Washington 0 LOG OF BORING B-312 0 October 2003 21-1-09369-002 mSHANNON 8�WIL$ON, INC. FIG. A-33 _ Geotechniral and Environmental Consultants LAl-3 SAMPLE DATA SOIL PROFILE GROUNDWATER o Dimling Method' HWbrr�eft Ater Hera $ on h Ground Ekvation(fl) to $ 5 tJ DNted By: Cascade Dtil4ng Inc. D SPY `. SM * � Pro6alF.e wNl a. rtwrnunart and cam"sa*I 2 6eN0nke d+ioe —4-ixh dhmoW, UW by m,San to medium SAND-th ado Set e0 ua 40.PVC wd AM gmnai 00030,MGM)Ina dew,rn CA An t a2 10 9 2 Q 2a 10 a 3 u 26 S � q ne tz sa vaea ATD IJxh 0iamaLr, SP Gmj,Amto m.*w SAND*Ah OrB Sdtcdtk 40,PVG (—c.wets(nf7*pht p.ao&-4AAt 06-. rpeel(9,0104%h&W no rnNn) �) a 4 a2 24 a g Ml bmMn.SILT with mcz ry st ,nlcitt)(n0 Tltraadad end cap -' S 12 26 0 ad".rro shy) to Sofro Completed o1AQ= U T.W Daplh d Ua;nq•WS M rn 0 i2 ¢ n7 o Jt 4 14 io 0 NOks; 1. Sbatipnphia vwUo 1a are bawd on new Inarpreledom artd art apprtar;nata. N 2.Refe eau to the upa d Whla sport It n---q-a proper vrdactandlnp d sobsvr M cvrdtions g 7. R-W t0'W CtaasXkat)on System sM W 5r"fw 0ck++0&M d WoOlka and$ "taok. m° Cono=PhtGips-Renton Figure co 14LANT AU Renton,m*mf ton Log of LAI-3 A-9 . ASSOCIATES Strander Boulevard / SW 27th Street 4 Improvements ' m Renton and Tukwila, Washington co LOG OF BORING B-313 October 2003 21-1-09369-002 e 0 SHANNON 8�WILSON, iNc. FIG. A-34 iD Geotachnical end Environmental Consultants LL LAI-1 b SAMPLE DATA SOIL PROFILE GROUNDWATER Dnjfng Meljwd: Hollow-stem Auger — n g to Gtound Elevation(fly k Y U Drilled 8y: Cascade Drillky 1nr- iit.e a1 m ° SM Lqtu brown,xky.Anw lo maeum SANE)wtm oaasaionvi praval pooic Meg(na a",no �tv.n1 _z ATO t ai 14 C —6 e — Ie ►1L — �rvw.t.SliT win;vie:,—ana una apan{ci, — — (mr�wm a —to ax.moot) 2 et 4 a y G 12 6orfnQ CoetpeSed atl291t]] Q TOW Owpei of Socbw=11.5 ft g 9 Q m 14 G S c " No m 1. ste"vphic awtwu we 1.sed an feed 8t<arpr.triata am aA app=*mae. 2. rte1e'ence b n-6A of"-p-K is nxtecuy 1w a prww unaersmnQine of e.daurf a w%dbe.u. C3. Refer 10'Sol rlu:lnasratt Syclam and Kre fipwe for eR*^aRnn a praoia and■ymbah. N r ConocoPhlllips-Renton TUre $ IAt�AU Term+nal Log of Boring LAI-16 �2 14 ASSOCIATES Do^f"^ Nlaihinaton QTnTa o Strander Boulevard /SW 27th Street $ Improvements Renton and Tukwila, Washington 0 LOG OF BORING B-314 October 2003 21-1-09369-002 0 SHANNON&WILSON, INC. FIG. A-35 o Geotechnkal and Environmental Consultants LL rPLATE 9 BORING NO. 5 ELEYATION: 16= FEET +G wAPH I C NEST DATA 1.0<: DESCRIPTION 0 SM BROWNISH GRAY SILTY SAND WITH GRAVEL AND CONCRETE RUBBLE (LOOSE TO MEDIUM DENSE, DAMP)(F1LL) 5 3 ® PT BROWNISH SILTY PEAT (SOFT, DAMP) IO 12 ML BROWNISH GRAY SILT WITH ORGANIC MATTER ® (SOFT, DAMP) 4 SP DARK GRAY FINE SAND WITH A TRACE OF 'SILT F 64.Ot 63 (LOOSE, WET) A LENS OF SILT AT 121 FEET IS 7 29.5% 91 OCCASIONAL WOOD FRAGMENTS AT 18 FEET 20 6 LAYERS OF SOFT SILT AT 2211 FEET 37.1% 83 0 25 I SM GRAY SILTY FINE TO MEDIUM SAND WITH SHELL FRAGMENTS (LOOSE, WET) U 0 30 L < 6 21.7% 105 0 1 35 4 m 7 BORING COMPLETED AT A DEPTH OF 39 FEET ON ° 0 2-6-82 40 STABILIZED GROUND WATER LEVEL NOT OBSERVED r0 PRIOR TO BACKFILLING BOREHOLE m +SF£ KEY FOR rD(7LA:L12ION OY STtW- LS N O GeoEngineers Inc. I«: of tocrloluTtm r 4 Strander Boulevard /SW 27th Street 4 Improvements Renton and Tukwila, Washington co LOG OF BORING B-315 October 2003 21-1-09369-002 ° = SHANNON &WILSON, INc. FIG. A-36 g Geotechnical and Environmental Conautta-is LL PI.hT 3 BORING NO. 1 ELEVATION: 17= FEET •GFJ�PHIC 0 *TEST DATA Lor DESCRIPTION SH BROWN SILTY SAND WITH GRAVEL AND CONCRETE ML RUBBLE (LOOSE, DAMP)(FILL) LIGHT GRAY SANDY SILT WITH OCCASIONAL GM GRAVEL (SOFT, -DAMP)CFILL) I 5 GRAY SILTY SANDY GRAVEL (LOOSE TO MEDIUM DENSE, DAMP)(FILL) i w 6 PT BROWN SILTY PEAT (SOFT, DAMP) 10 46.71 75 N ML BROWNISH GRAY TO GRAY SILT WITH ORGANIC H MATTER (SOFT, DAMP) a SP DARK GRAY FINE TO MEDIUM SAND WITH LENSES w OF SILT (LOOSE, WET) O 15 9 45.3% 75 20 ML BROWNISH GRAY 70 GRAY SILT WITH A TRACE OF g ORGANIC MATTER AND LENSES OF SAND (SOFT, DAMP) 25 , 2 34.61 85 SM GRAY SILTY SAND WITH SHELL FRAGMENTS 30 (LOOSE, WET) a 2 C1 23.9% 102 o 604 3 S 4 6 o � SP n 40 C m SEE 10EY FOR EXpi11i7ATI0N OF STTWLS N O to GeoEngineers Inc. LOt: of EXPLf1RATTmt q Strander Boulevard/SW 27th Street 4 Improvements Renton and Tukwila, Washington m 0 LOG OF BORING B-316 October 2003 21-1-09369-002 SHANNON&WILSON,INC. FIG. A-37 g Geotechnkal and Environmental Consultants Sheet 1 Of 2 ii P AT 4 BORING NO. 1 (CONTINUED) •GItiAPHIC 40 *TEST DATA LOC. DESCRIPTION SP GRAY FINE TO MEDIUM SAND WITH OCCASIONAL 22 SHELL FRAGMENTS (MEDIUM DENSE, WET) 24.5% 100 45 20 w50 z M 28 ' W 26.11 97 c 55 17 60 BORING COMPLETED AT A DEPTH OF 59 FEET ON 2-6-82 . STABILIZED GROUND WATER LEVEL NOT OBSERVED PRIOR TO HACKFILLING BOREHOLE 0 g 9 4 m c m *SEE KEY FOR EXPi.A:lATION OF SYt+E,OI_S N GeoEngineers Inc. L0r OF EXTLclRAT10:i 4 ' Strander Boulevard/ SW 27th Street 4 Improvements Renton and Tukwila, Washington m 0 S1 LOG OF BORING B-316 e October 2003 21-1-09MJ-002 0 SHANNON &WILSON, INC. FIG. A-37 Geotechnical and Environmental Consultants Sheet 2 of 2 i 1 1 1 ' TEST PIT SEVEN ELEVATION: 171 FEET 0 SM GRAYISH BROWN SILTY SAND WITH GRAVEL, CONCRETE RUBBLE, POCKETS OF SILT AND OTHER DEBRIS (LOOSE TO MEDIUM DENSE WET TO DAMP)(FILL) GRADES TO VERY WET AND SOFT AT 4 FEET S)i - 10'j PT DARK BROWN SILTY PEAT WITH ROOTS AND WOOD CSOFT, DAMP) ML/OL GRAYISH BROWN SILT WITH ORGANIC MATTER (SOFT, WET) TEST PIT COMPLETED AT 11 FEET ON 10/S/81 NO GROUND WATER SEEPArE OBSERV DISTURBED SAMPLES OBTAINED AT 3, 9 AND 11 FEET GeoEn5 ineers Inc. TEST PIT LOGS Q L O Q M O 9 Q m W Q N F N O 4 m 4 Strander Boulevard/SW 27th Street 4 Improvements Renton and Tukwila, Washington Cn LOG OF TEST PIT TP-304 October2003 21-1-09369-002 0 SHANNNNON&WI SON, INC�. FIG- A-38 TES' PIT SIXTEEN ELEVATION: 16` FEET 0 - $ GM BROWN VERY SILTY GRAVEL WITH ORGANIC MATTE,'. AND SO1iE SAND (LOOSE TO MEDIUM DENSE, DAMP) (FILL) ABUNDANT WOOD AT FEET 8 _ 9� PT BROWN SILTY PEAT (SOFT, DAMP) 91 - 123 ML GRAY SILT SMITH ORGANIC MATTER (SOFT, DAMP) 11' - 1.21' SP DARK GRAY FINE SAND WITH A TRACE OF SILT (LOOSE, WET) TEST PIT COMPLETED AT 12} FEET ON 2/3/S2 ' GROUND WATER SEEPAGE OBSERVED AT 12 FEET DISTURBED SAMPLES OBTAINED AT 21, 81, 10 AHD 12 FEET GeoEnginears Inc. TES' P1T LOGS U o Q 04 4 m ' a tm- QN T Q) cD f) 4 Strander Boulevard /SW 27th Street 4 Improvements Renton and Tukwila, Washington 0 LOG OF TEST PIT TP-305 ' October 2003 21-1-09369-002 f° 0 SHANNON&WILSON, INC. FIG. A-39 m Geota&nical and Env ronmental Consultants ii Hole No. B-1 PROJECT:Lind Avenue Warehouse LoATE DRILLED:7/20/94 DRILL RIG: Truck-mounted LOGGED BY:Mark Dodds,P.E. HOLE DIA: 8 in. SAMPLER: SPT INITIAL WATER DEPTH:20.0 ft. HOLE ELEV: 1 Road S.H. 29th Street FINAL WATER DEPTH: 20.0 ft. TOTAL DEPTH:39 It. N W DESCRIPTION SOIL GRAPHIC BLOWS REMARKS TYPE LOG 4 /Ft. to Sut lace -Brown orasses and weeds. &own gravEwy silty Sand with Fill 0 some coDoles.line grdned,moist,loose to medrum-dense. 1FY11 Gray silly Sand,medum-graved,very moist,Bose. [Full 5 Moisture content - 82.4% L.L. DaiM Drawn liorous organic Sill,wet,soft. OH = 64.4%P.I. - 14.4% i� 5 Brown s+ty Sand and Sat,line to meawro graved,wet,soft. SM/ML 3 Moisture content = 32.5% 10 Gray silty Sand, line to meomn gramea,wet.loose. SM e Moisture content -37.7% IS Gray Srlt,wet,soft. ML 3 Moisture content- 53.3% Passing No. 200- 98.5% Gray sandy S.it,saturated,memum-sense. ML 20 = Grountlwaler seepage. 14 Moisture content - 34.0% Passing No. 200 - 68.2% � 25 m o Becomes soli. 2 Moisture content= 35.2% Passing No. 200-52.9% a 30 6 4 m Some shes fragments. 5 Moisture content = 24.1% W 0 35 ENVIRONMENTAL Assom11T.s.INc. 0 0 ca tom of Borng 1. Groundwater at s20.0 feet on 7120194. RN T 4) 9 Q Strander Boulevard/SW 27th Street 4 Improvements Renton and Tukwila, Washington 0 LOG OF BORING B-317 0 October2003 21-1-09369-002 CGeootteachn�OenddEnvironmental Coons'�ts FIG. A-40 TEST . IT 7 o _ (n DATE EXCAVATED:7/21/94 n c N i EXCAVATION METHOD.Rubber-tired Backhoe u o v"i a o LOGGED BY:Uoyd J.Reitz. E.I.T. ' to o s rn co DESCRIPTION SURFACE ELEVATION: s S.W.281h St. 0 Surface -Weeds �5 Tan silty gravelly Sand, fine grained, dry,medium dense. 2 5 Becomes blue to gray in color, moist. �5 4 �5 Becomes wet,loose. S OL 6 I I Dark brown sandy organic Silt with roots, very moist, soft. 1 6.5-7.0 83.4% I 1 (old topsoil) IIIII 2 8.5-9.0085.6X MH 8 Brown sandy Sill with some organics, very moist. soil. I ' 10 SP Black sand with trace sill, fine grained,very moist,loose. ' 12 Stopped at 12.0 feel. Caving at 4'10 6 feet. Groundwater at 6 le,I during excavation. 14 ' Ua N o a �_.� ENVIRONMENTAL ASSOCI l7FS,INC O 4 m U N O 4 O) m f) Q Strander Boulevard/SW 27th Street 4 Improvements m Renton and Tukwila, Washington 0 LOG OF TEST PIT TP-306 o October 2003 21-1-09369-002 o SHANNON&WILSON,INC. FIG. A-41 Geotachnlcal and Environmental Consultants BORING NO. Logged By Jws Date 1/10/85 ELEV. 1_ 6= Graph US Soil Description Depth Sample BloNws W CS (ft.) Ft. (°) gray silty SAND, fine grained, with sm greenish sandy silt layers, moist, medium dense (FILL) = 21 13 _ 5 4 = 4 24 - pt brown PEAT, amorphous, soft to medium 1/lf3 S ' beconing wet very o P HH gray clayey SILT, wet, medium stiff to = 10 67 1.5 tsf stiff 10 LL=57 Z 13 31 PI=23 sm black red-speckled silty SAND, wet, medium dense 12 32 �rf sm gray silty SAND grading to sandy SILT 15 X4 •t ml w/silty sand lenses wet medium dense :'t�MWFCM m black red-speckled silt. SAND, wet, = 9 30 medium dense 20 gray clayey SILT, wet, soft to I�1��11221� Mpdiurl < ;Ff 9 33 sm gray sandy SILT with sand lenses, wet, 25 � I ml loose, slight plasticity I 0 47 c=.2 tsf li ml gray clayey SILT with silty sand lenses, 30 wet, soft, moderate plasticity I cep r�Ffi�t:: I•Fti•i`r> 3 30 35 I'I=1•: : sm gray silty SAND with clay and shells, wet, very loose 7 27 •.::i.:�?;; 40 becoming dense @ 42' :•si ;. 51 251 m ' c Boring terLiinated at 44' below existing grade. Groundwater observation well installed to 191. m . g q m 0 BORING LOG 'I PROPOSED 11JUMFACTURING SIT£ o Earth RENTot7, WASHINGTOt7 N Consultants Inc. 99i GEOTECHNICAL ENGINEERING 6 GEOLOGY Proj.No. 2533 Date Jan. Plate 4 9 M Q Strander Boulevard/SW 27th Street $ Improvements Renton and Tukwila, Washington 0 LOG OF BORING B-318 Cn o October 2003 21-1-09369-002 m SHANNON &WILSON,INC. FIG. A-42 Geolechnical and Environmental Consultants lmsstn Itiftfllf■llaliR■ _�So IS�liff•ififfmilyllli�mm ■ttlmm■ts �issilllll�t a�lfw510� =;■A rm■■t1lfm�mff/�i�lmlmlm■ f� ' • • . tifmmMnittttti��:.tfmtltl/mmO •a1mmlNs lm/=s■Illilr pimf■1/Illntl■m■ f>t■■ss! ftii■■t111trri■ff■Itlilll■Il•■ it■!■■■■ �w■■t1111igmtiffit1111/I me f.E■■■m■ •„ ,• �mmm'1/1iR►ta�tllt11ammo ■■a■O ■�i■Mae III flt■11111■mE t�■■■■■ t�lm■mtI11I��m■�fl/Ilptll■m■ m►�ou■m _ fS1■■■ttlll�ltf•■ffnlltml■/■■ saillm■m ti�f•fl■tt.••!�i■ffltllnlU■■t■ ■■��■1■ Isom■MIRY/I■flimffltllu=m■ If■_noun tt�mmlff�i�:V���I�tllalll��i / • tt�=mo/II1�ttt1lit��Mff1/111ntlsm■ .v■mzm■ ■Itit WI•►'n■Nltl I mmno ifl■■mEO ® . .. t■f•i■■tIt1�IfA.V■flt�a■f■■ q■Y■Iv fm■m■■Illll��ifomalamm■ l•■ft■m■M f♦f♦■tIR:111�imlfltllllllmm■ ■t■.7■■■ son <iff11111a11■i■ ■■m■■■■ ��■■Vllllffslmofflulutnsm■ ■UNNI■m . 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Attachment to and part of Report 21-1-09369-002 ._ Geotechnical and Environmental Consultants Date: May 21, 1004 To: Mr.Rich Perteet Perteet Engineering,Inc. IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL/ENVIRONMENTAL REPORT CONSULTING SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES AND FOR SPECIFIC CLIENTS. Consultants prepare reports to meet the specific needs of specific individuals. A report prepared for a civil engineer may not be adequate for a construction contractor or even another civil engineer. Unless indicated otherwise,your consultant prepared your report expressly for you and expressly for the purposes you indicated. No one other than you should apply this report for its intended purpose without first con::erring with the consultant. No party should apply this report for any purpose other than that originally contemplated without first con::erring with the consultant. THE:CONSULTANT'S REPORT IS BASED ON PROJECT-SPECIFIC FACTORS. A geotechnical/environmental report is based on a subsurface exploration plan designed to consider a unique set of project-specific factors. ' Depending on the project, these may include: the general nature of the structure and property involved; its size and configuration; its historical use and practice;the location of the structure on the site and its orientation;other improvements such as access roads,parking lots, and underground utilities; and the additional risk created by scope-of-service limitations imposed by the client. To help avoid costly ' problems,ask the consultant to evaluate how any factors that change subsequent to the date of the report may affect the recommendations. Unless your consultant indicates otherwise,your report should not be used: (1)when the nature of the proposed project is changed(for example, if an office building will be erected instead of a parking garage, or if a refrigerated warehouse will be built instead of an unrefrigerated one,or chemicals are discovered on or near the site);(2)when the size,elevation,or configuration of the proposed project is altered; (3) when the location or orientation of the proposed project is modified; (4) when there is a change of ownership; or (5) for application to an adjacent site. Consultants cannot accept responsibility for problems that may occur if they are not consulted after factors which were considered in the development of the report have changed. SUBSURFACE CONDITIONS CAN CHANGE. Subsurface conditions may be affected as a result of natural processes or human activity. Because a geotechnical/environmental report is ' based on conditions that existed at the time of subsurface exploration, construction decisions should not be based on a report whose adequacy may have been affected by time. Ask the consultant to advise if additional tests are desirable before construction starts; for example,groundwater conditions commonly vary seasonally. Construction operations at or adjacent to the site and natural events such as floods,earthquakes,or groundwater fluctuations may also affect subsurface conditions and,thus,the continuing adequacy of a geotechnical/environmental report. The consultant should be kept apprised of any such events, and should be consulted to determine if additional tests are necessary. tMOST RECOMMENDATIONS ARE PROFESSIONAL JUDGMENTS. Site exploration and testing identifies actual surface and subsurface conditions only at those points where samples are taken. The data were extrapolated by your consultant,who then applied judgment to render an opinion about overall subsurface conditions. The actual interface between materials may be far more gradual or abrupt than your report indicates. Actual conditions in areas not sampled may differ from those predicted in your report. While nothing can be done to prevent such situations,you and your consultant can work together to help ' reduce their impacts. Retaining your consultant to observe subsurface construction operations can be particularly beneficial in this respect. Page 1 of 2 1/2004 A REPORT'S CONCLUSIONS ARE PRELIMINARY. The conclusions contained in your consultant's report are preliminary because they must be based on the assumption that conditions ' revealed through selective exploratory sampling are indicative of actual conditions throughout a site. Actual subsurface conditions can be discerned only during earthwork;therefore,you should retain your consultant to observe actual conditions and to provide conclusions. Only the consultant who prepared the report is fully familiar with the background information needed to determine whether or not the report's recommendations based on those conclusions are valid and whether or not the contractor is abiding by applicable recommendations. The consultant who developed your report cannot assume responsibility or liability for the adequacy of the report's recommendations if another party is retained to observe construction. THE:CONSULTANT'S REPORT IS SUBJECT TO MISINTERPRETATION. Costly problems can occur when other design professionals develop their plans based on misinterpretation of a geotechnical/environmental report. To help avoid these problems,the consultant should be retained to work with other project design professionals to explain relevant ' geotechnical,geological,hydrogeological,and environmental findings,and to review the adequacy of their plans and specifications relative to these issues. BORING LOGS AND/OR MONITORING WELL DATA SHOULD NOT BE SEPARATED FROM THE REPORT. Final boring logs developed by the consultant are based upon interpretation of field logs(assembled by site personnel),field test results,and laboratory and/or office evaluation of field samples and data. Only final boring logs and data are customarily included in geotechnical/environmental reports. These final logs should not,under any circumstances,be redrawn for inclusion in architectural or other design drawings,because drafters may commit errors or omissions in the transfer process. To reduce the likelihood of boring log or monitoring well misinterpretation, contractors should be given ready access to the complete geotechnical engineering/environmental report prepared or authorized for their use. If access is provided only to the report prepared for you,you should advise contractors of the report's limitations,assuming that a contractor was not one of the specific persons for whom the report was prepared,and that developing construction cost estimates was not one of the specific purposes for which it was prepared. While a contractor may gain important knowledge from a report prepared for another party,the contractor should discuss the report with your consultant and perform the additional or alternative work believed necessary to obtain the data specifically appropriate for construction cost estimating purposes. Some clients hold the mistaken impression that simply disclaiming responsibility for the accuracy of subsurface information always insulates them from attendant liability. Providing the best available information to contractors helps prevent costly ' construction problems and the adversarial attitudes that aggravate them to a disproportionate scale. READ RESPONSIBILITY CLAUSES CLOSELY. ' Because geotechnical/environmental engineering is based extensively on judgment and opinion, it is far less exact than other design disciplines.This situation has resulted in wholly unwarranted claims being lodged against consultants. To help prevent this problem, consultants have developed a number of clauses for use in their contracts,reports and other documents. These responsibility clauses are not exculpatory clauses designed to transfer the consultant's liabilities to other parties;rather,they are definitive clauses that identify where the consultant's responsibilities begin and end. Their use helps all parties involved recognize their individual responsibilities and take appropriate action. Some of these definitive clauses are likely to appear in your report,and you are encouraged to read them closely. Your consultant will be pleased to give full and frank answers to your questions. The preceding paragraphs are based on information provided by the ' ASFE/Association of Engineering Firms Practicing in the Geosciences,Silver Spring,Maryland Page 2 of 2 1/2004