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Home My WebLink AboutGEO General - 1/22/2007 Aspectconsulting IN-DEPTH PERSPECTIVE SUBSURFACE EXPLORATION, GEOLOGIC HAZARD AND GEOTECHNICAL E GINEERING REPORT Highway 101 Facility Mason County, Washi gton Prepared for: Mason County Public Works Department Project No. 060159-005-01 • January 221, 2007 ASectconsuttin p g IN-DEPTH PERSPECTIVE SUBSURFACE EXPLORATION, GEOLOGIC HAZARD AND GEOTECHNICAL ENGINEERING REPORT Highway 101 Facility Mason County, Washington Prepared for: Mason County Department of Public Works Project No. 060159-005-01 • January 22, 2007 Aspect Consulting, LLC BREW p �kGODof��as 41856 Qk' rt� FCIS'► �stUNAL ti�G 18302� E/2,Jc)7 �SjOIVAL�'` EXPIRES 9/3/o James A. Peterson, PE John L. Peterson, PE Project Geotechnical Engineer Associate Geotechnical Engineer apeterson@aspectconsulting.com jpeterson@aspectconsulting.com WA GEOTECH\060159 Mason County\Public Works Facility-005\Highway 101 Facility Geotechnical Evaluation.doc 179 Madrone Lane North. • ••- • i 1. :i Y 1. :1 •- • ASPECT CONSULTING Contents 1 Project and Site Conditions........................................................................1 1.1 Introduction ................................................................................................ 1 1.1.1 Purpose and Scope.............................................................................. 1 1.1.2 Authorization ........................................................................................1 1.2 Project and Site Description....................................................................... 1 1.2.1 Exploration Pits ....................................................................................2 1.3 Subsurface Conditions...............................................................................2 1.3.1 Topsoil and Forest Duff........................................................................3 1.3.2 Weathered Glacial Outwash.................................................................3 1.3.3 Glacial Outwash ...................................................................................3 1.3.4 Hydrology.............................................................................................3 2 Geologic Hazards and Mitigations .............................................................4 2.1 Seismic Hazards and Recommended Mitigation ........................................4 2.2 Erosion Hazard ..........................................................................................4 2.2.1 Mitigation..............................................................................................4 2.3 Landslide Hazards and Mitigation ..............................................................4 3 Design Recommendations..........................................................................5 3.1 Introduction ................................................................................................5 3.2 Site Preparation .........................................................................................5 3.3 Structural Fill..............................................................................................5 3.4 Foundations ...............................................................................................5 3.5 Floor Support .............................................................................................6 3.6 Drainage Considerations............................................................................6 3.7 Parking and Access Areas.........................................................................7 3.8 Pavement Design.......................................................................................7 3.9 Soil Infiltration Criteria................................................................................8 3.10 Reuse of Site Soils.....................................................................................8 3.11 Additional Project Design Information and Construction Monitoring..........9 Information about this Report....................' ....................................................10 I List of Figures 1 Site Location Map 2 Site and Exploration Plan PROJECT NO.060159-005-01 • JANUARY 22, 2007 i ASPECT CONSULTING 1 Project and Site Conditions 1 .1 Introduction This report presents the results of our subsurface exploration, geologic hazard, and geotechnical evaluation of the site soils for the proposed Highway 101 Public Works facility project in Mason County, Washington. This investigation and report were completed at the request of the Mason County Department of Public Works (MCDPW). The location of the site is presented on the Site Location Map, Figure 1. 1.1.1 Purpose and Scope The project consists of construction of a new MCDPW maintenance and office facility near the intersection of State Road 102 and U.S. Route 101 northwest of Shelton. The purpose of this study was to provide subsurface data to be utilized in evaluating the site soils for stormwater and septic infiltration, suitability of site soils for reuse as road subgrade material, and allowable bearing capacities for foundations. Our study included review of available geologic literature, excavation of seventeen soil exploration pits,and geologic studies to assess the type, thickness, distribution and physical properties of the subsurface sediments. This report summarizes our current field work and offers our opinion of the development plans based on our present understanding of the project. 1.1.2 Authorization Written authorization to proceed with this study was granted by Robert Thuring on December 4, 2006. Our study was accomplished in general accordance with our scope of work contract dated November 14, 2006. 1 .2 Project and Site Description This report was completed with an understanding of the project based on conversations with Mr. Bob Thuring of MCDPW, and onsite discussions with MCDPW personnel using a preliminary site plan provided by Skillings Connolly, the project civil engineers. MCDPW also provided a map of the project area showing requested exploration pit locations with location identifiers. We understand that a new Public Works facility with five buildings, a fuel station and associated parking areas is planned for the site. The initial scope of work called for evaluating site soils for stormwater infiltration, septic design, and general development criteria. Subsequent discussions in the field with MCDPW personnel suggested that municipal sewer service would be available by the time of construction. The project site is located several miles northwest of Shelton, Washington, on the west side of U.S. Route 101, approximately '/4 mile north of the intersection with State Road 102. The site area(based on the Skillings Connolly Plan) is shown on Figure 2, Site and PROJECT NO.060159-005-01 •JANUARY 22, 2007 1 ASPECT CONSULTING interpretation of conditions in other areas based on our site reconnaissance. The deposits are listed in order from generally younger to older. 1.3.1 Topsoil and Forest Duff A thin layer of dark brown, silty, organic-rich, gravelly sand was encountered in all exploration pits.This upper zone is interpreted as topsoil and/or forest duff. The maximum observed depth of topsoil was approximately 8 inches. 1.3.2 Weathered Glacial Outwash A layer of loose,reddish-brown, silty, gravelly sand to sandy gravel with abundant roots was encountered in all exploration pits from beneath the topsoil/forest duff layer to depths ranging from 1.2 feet in S-3 to 2.5 feet in TH-1004. This stratum is interpreted as the upper, weathered facies of the underlying glacial outwash stratum. Due to its loose state and organic content,this stratum is not suitable for foundation support of any proposed structures. 1.3.3 Glacial Outwash Medium dense to dense, brown to gray, sandy gravel with numerous cobbles and scattered small boulders was encountered in all exploration pits from beneath the weathered outwash stratum to the full explored depth. This stratum is interpreted as proglacial outwash sediments deposited in advance of the most recent glaciation of the Puget Sound lowland region approximately 18,000 years ago. Large quantities of silt, sand and gravel were deposited by high energy pro-glacial streams exiting the toe of the ice sheet as it advanced south through the Puget Sound region. After deposition, the outwash sediments and those sediments stratigraphically lower were overridden and consolidated by the weight of thousands of feet of glacial ice. As a result of this consolidation, these soils typically exhibit high strength and low compressibility characteristics and are suitable for foundation support. This is consistent with the published geological maps of the regions which indicated recessional to proglacial outwash,with nearby zones of surficial glacial till and some lower exposures of advance outwash. 1.3.4 Hydrology No groundwater seepage was encountered in any of the test pits, although several test pits had increasing moisture content in the deepest samples. All other explorations indicated moist soil conditions. No mottling was observed in any of the test pits. All of the glacial outwash soils encountered in the exploration pits exhibited excellent drainage characteristics. No groundwater seepage was observed on the slope at the northwest corner of the property. PROJECT NO.060159-005-01 • JANUARY 22,2007 3 ASPECT CONSULTING 3 Design Recommendations 3.1 Introduction Our explorations indicate that the site is suitable for the proposed facilities construction and that the site soils exhibit excellent drainage characteristics and are suitable for use as road subgrade material. 3.2 Site Preparation Any relic buried utilities should be removed or relocated if they are under the building areas. The resulting depressions should be backfilled with structural fill as discussed under Section 3.3, Structural Fill. Site preparation within the proposed building footprint areas should include removal of all organics, debris, and any other deleterious material that may be encountered at or near the surface. Areas where loose surficial soils exist due to past grading or current construction operations should be considered as fill to the depth of disturbance and treated as subsequently recommended for structural fill placement. The contractor should use care during site preparation and excavation operations so that the exposed soils are not softened. Softened soils will make construction access and near- surface earthwork difficult. If disturbance occurs, the softened soils should be removed and the area brought to grade with structural fill. 3.3 Structural Fill Based on the current construction plans, it is our understanding that the use of structural fill might be necessary to establish desired grades in some building areas. In general,we recommend that all structural fill be free of organic material, be placed in loose lifts no greater than 12 inches thick, and compacted to at least 95 percent of the ASTM test designation D-1557 (modified Proctor) dry density. However,wall backfill should be limited to 90 percent of compaction unless higher compaction is determined necessary. If necessary, specific placement recommendations for wall backfill will be made once the foundation design is finalized. Structural fill soils used should be approved by Aspect Consulting prior to placement. 3.4 Foundations We understand that five separate buildings for maintenance and office space are planned, plus a fueling station. Spread footings may be used for building support when founded in the medium dense to dense, intact glacial outwash sediments encountered at depths ranging from 1.2-feet in S-3 to 2.5 feet in TH-1004. We recommend a maximum allowable foundation bearing pressure of 2,500 pounds per square foot (psf)be utilized for design purposes, including both dead and live loads for PROJECT NO.060159-005-01 • JANUARY 22,2007 5 ASPECT CONSULTING 3.7 Parking and Access Areas Parking areas outside the proposed building footprint should be excavated a minimum of 2 feet below design grade, and the subgrade compacted to at least 90 percent of maximum dry density. The prepared areas should then be backfilled and compacted with structural fill compacted to 95 percent of modified Proctor maximum density to design grade. In areas where unweathered glacial outwash soil exists within 2 feet of the surface and the in-situ weathered soils are free of organics, the parking lot subgrade can be compacted in place with an appropriately sized vibratory drum roller. 3.8 Pavement Design We understand that flexible pavement will be installed to provide vehicle access to the site and that both heavy and light vehicular traffic is anticipated. The majority of traffic to the site will be private cars and trucks. Heavy traffic will consist of road maintenance vehicles. Since traffic loading data were not available at the time of this report,we assumed an IS-kip Equivalent Axle Loading(EAL) of 1,000,000 for the design life of the pavement.This loading represents, approximately, 175 large dump trucks trips(in/out) per week for ten years. For areas which would not receive heavy truck loading, a lesser design section could be utilized if desired. The information gathered in the field was analyzed and used to complete pavement design. The majority of the existing in-situ material encountered below the proposed existing roadway had an estimated moderate to high number of SPT(standard penetration _ test)blow counts(25 to 50+). Site materials used as fill, compacted to 95 percent of maximum density as determined by ASTM 1557,would be estimated to have a SPT blow count of at least 25. The blow counts were converted to a California Bearing Resistance (CBR)number. For the pavement design, a CBR of 20 was assumed, as this will provide a conservative result. The pavement sections were determined by following the American Association of State Highway and Transport Officials (AASHTO) design method and the Spectra®Base Reinforcement program. Based on the CBR values and an equivalent 18-kip axle loading of 909,000 cycles, a Structural Number(SN) of 2 was calculated to be necessary for the upper pavement elements. Two pavement construction sections were evaluated. Both sections consisted of asphalt underlain by a crushed rock base and subgrade material. One section uses a thinner pavement section and reinforcing material below the leveling base course and the other a thicker pavement section. Both sections use the in-situ or recompacted site fill as subgrade material. Where material is disturbed through excavation to meet grade or by disturbance with construction equipment, the exposed ground should be re-compacted to at least 95 percent of the above referenced standard. Prior to placing crushed material, the entire surface area should be proof-rolled using a 16-ton vibratory roller. If soft or yielding`areas are identified, they should be scarified and re-compacted. With the first construction section, the design pavement section consists of 3 inches of Washington State Class B Asphalt underlain by 4 inches of 11/a-inch minus crushed surfacing top course overlying existing subgrade material. A layer of Tensar BX-1000 PROJECT NO.060159-005-01 • JANUARY 22, 2007 7 y ASPECT CONSULTING The site soils below approximately 2 feet depth are suitable for reuse as road subgrade as- is, with only screening for boulders and larger cobbles necessary. If smaller cobbles are retained in the road subgrade fill, lift thickness when placing fill should be twice the largest cobble dimension to avoid nesting and resultant voids in the subgrade. Drum rollers with compaction force of approximately 16 tons may be needed for thick lift compaction. Alternatively, the site soils could be processed through a crusher, so that the cobbles and boulders were reduced to an acceptable grain size,with the added benefit of providing some fines content and angularity of the resulting gravel-sized pieces produced. In this case the lift thickness could be reduced from that of a coarser, oversize- based material. 3.11 Additional Project Design Information and Construction Monitoring At the time of this report, site grading and construction methods have not been finalized and the recommendations presented herein are preliminary. We are available to provide additional geotechnical consultation as the project design develops and possibly changes from that upon which this report is based. We are also available to provide geotechnical engineering and any required monitoring services during construction. In addition, engineering decisions may have to be made in the field in the event that variations in subsurface conditions become apparent. PROJECT NO. 060159-005-01 • JANUARY 22,2007 9 V,, 6 B-n rOC& + 125 "2067 8orrow 266 Z BM273 6 r 4, �A-------------------------------- A- N� end Lake : 248r o W.6' PA 4 5- IWL. ir I & IV 1XI f Site Location 2\. TE T Jo WIL 4- 91 L Wash sPat0 WT' vs t , 11- I -'T..49 Ac Lake 71 isione O C'.. i T ra cj1 Island L IN f 5.9 9 c� BM BM 83.7 1 84.4 SAN ERSON if F ELD j cc LL BM 7 '2- Feet 2 PROJECTNO. Site Location Map Jan 2007 co qh Awedconsulting 9 060169-005 IN-DEPTH PERSPECTIVE JAP on xes. NO. FT 179 Md,-L—N." 811Fi*A—.#480 Proposed Public Works Facility PM8 FIGURE 0 B.MbHdI.I.I.M.WA 981IG Uaft,WA 98104 (206)780-9370 (208)325-7443 Mason County,Washington Legend TH-1015 Approximate Exploration Pit Location M{ 313 p 3t3 ?l.I, 3N 24 3p w TH-1001 262 3: L zz 30 TH-1000 - t -- �' TA-1016 " TH-1014 �- S-3 S-2 S-1 c_ TH-1015� ' t1-1013 310 e 30+ 1 ro Reference:Site Plan by Skillings/Connolly,dated APPENDIX A Exploration Pit Logs t E = o, 0 Well-graded gravel and Terms Describing Relative Density and Consistency �N o o. GW gravel with sand, little to Density SPT(2)blows/foot • 0 no fines Very Loose 0 to 4 ° iL Coarse Loose 4 to 10 Q) ' °°°°° Poorly-graded ravel Grained o 0°o°o Y 9 9 Medium Dense 10 to 30 Test Symbols in — vu00000 Gp and gravel with sand, Dense 30 to 50 o ° 6 0°0°0 little to no fines Very Dense >50 G=Grain Size N o z °0°0° M=Moisture Content 6 o C p Consistency SPT")blows/foot A=Atterberg Limits z c Silty gravel and silty Very Soft 0 to 2 C=Chemical 0 4 °' • • GM gravel with sand Fine- Soft 2 to 4 DD = Dry Density G y c, m •0• Grained Soils Medium Stiff 4 to 8 K=Permeability M6 � of it N � Clayey ravel and Stitt 8 to 15 Y y g Very Stiff 15 to 30 N) GC clayey gravel with sand Hard >30 12 Component Definitions 0 Well-graded sand and Descriptive Term Size Range and Sieve Number w o "Z : gyy sand with gravel,little Boulders Larger than 12" W to no fines Cobbles 3"to 12" Gravel 3"to No.4(4.75 mm) > .: .. Poorly-graded sand Coarse Gravel 3"to 3/4" U) ci °' �� and sand with gravel, Fine Gravel 3/4"to No.4 4.75 mm cn SP ( ) c m v little to no fines Sand No.4(4.75 mm)to No.200(0.075 mm) f0 0 z° Coarse Sand No.4(4.75 mm)to No.10(2.00 mm) q 2 Silty sand and 6 , a Medium Sand No.10(2.00 mm)to No.40(0.425 mm) ° rn SM silty sand with Fine Sand No.40(0.425 mm)to No.200(0.075 mm) co o co -_ .: . U o o gravel Silt and Clay Smaller than No.200(0.075 mm) NClayey sand and (3) All SC clayey sand with gravel All Percentage Moisture Content cin Percentage Dry-Absence of moisture, by Weight Modifier dusty,dry to the touch Silt, sandy silt,gravelly silt, <5 Trace Slightly Moist-Perceptible (D C> ML silt with sand or gravel moisture ro C 5 to 15 Slightly(sandy,silty, Moist-Damp but no visible m T Co clayey,gravelly) water C) f° N Clay of low to medium 15 to 30 Sandy,silty,clayey, Very Moist-Water visible but 04 O V1 not free draining z o -1 CL plasticity;silty, sandy,or gravely) 9 v, N B gravelly clay, lean clay 30 to 49 Very(sandy,silty, Wet-Visible free water,usually (D = clayey,gravelly) from below water table `n m _ Organic clay or silt of low a cr _ _ symbols Cement grout a7 D = OL plasticity Blows/6"or surface seal Sampler portion of 6" Type / B Ptonite Elastic silt,clayey silt,silt 2 0"CD i Sampler Type chips o N MH with micaceous or diato- Split-Spoon Description Bentonite u' o maceous fine sand or silt Sampler 20 14) seal U) g (SPT). Continuous Push N 0 3.25"OD Split-Spoon Rin Sam Sampler Filter pack with 'o og p � ': blank casing U) C5 o Clay of high plasticity, `4) - section �' sand or ravel) clay,fat Bulk sample 4) c = CH Y gravelly Y. 3.0"OD Thin-Wall Tube Sampler Screened casing Y E clay with sand or gravel (including Shelby tube) or Hydrotip with — o Grab Sample filter pack M -- c D /j�j%raj Organic clay or silt of O Portion not recovered End cap 'a riri OH medium to high t,l rrri�irir plasticity Percentage by dry weight ts) Combined USCS symbols used for c rri rri (2) (SPT)Standard Penetration Test fines between 5%and 15%as C: Peat,muck and other (ASTM D-1586) estimated in General Accordance > t3) In General Accordance with with Standard Practice for pT highly organic soils „ mco Standard Practice for Description Description and Identification of LL = O and Identification of Soils(ASTM D-2488) Soils(ASTM D-2488) v t°l Depth of groundwater a ATD=At time of drilling 1 Static water level(date) z a z Classifications of soils in this report are based on visual field and/or laboratory observations,which include density/consistency,moisture condition,grain size,and a plasticity estimates and should not be construed to imply field or laboratory testing unless presented herein.Visual-manual and/or laboratory classification v` methods of ASTM 0-2487 and D-2488 were used as an identification guide for the Unified Soil Classification System. a e PROJECT NO. N Aspect consulting Cr fIV-DEP7N PERSPEC77VE Exploration Log Key C FIGURE NO. < 179 Medn La"e NM 811 Rmt ABM#460 �- < Bainbdd9e)eland,WA 98110 S-ft,WA 98104 rtEvrsFuer. (206)780�9370 (206)77B-7443 C ASt Exploration/Test Pit peC consulting Project Number Exploration Number Sheet IN-DEPTH PERSPECTIVE 060159 005 THA C 1 of 1 Project Name Mason County DPW Highway 101 Site Ground Surface Elev 314 Location See site plan for location/Shelton,WA Contractor/Method Mason County DPW/ Depth to Water N/A Sampling Method Grab Sample Start/Finish Date 1/4/2007 Depth Sample PID Material Depth Elevation Tests/Remarks ks(feet) TYPeAD (PPm) Type Description (ft) TOPSOIL/FOREST DUFF WEATHERED OUTWASH Loose to medium dense,reddish-brown,moist,silty, gravelly,SAND(SM);roots 1 313 1 2 312 N/A GLACIAL OUTWASH DEPOSITS 2 Dense to very dense,gray,moist,gravelly SAND,trace silt (SW);with cobbles;gravel is fine to coarse,sand is fine to coarse 3 311 3 4 310 q 5 309 5 6 308 707 0 Dense to very dense,gray,moist,sandy GRAVEL,trace 6 S-1 o silt(GW);with cobbles;gravel is fine to coarse,sand is o o fine to coarse op 7 307 �0�0 c� 7 o°o, ODoO O ODOD 0 8 306 0 0 0 o Increasing cobbles with depth 8 0 000, n iv O c�v o000 9 305 DODO g = o a q o ODOD 10 304 10 S-2 �0�0 o � Bottom of exploration at 10.5 feet. oNo groundwater observed,excavation walls standing U vertical) . o Sampler Type: PID-Photoionization Detector(Headspace Measurement) Logged by: DFR/JAP ® No Recovery 1 Static Water Level a ®Grab Sample Water Level(ATD) Approved by: JLP w Q Groundwater Seepage(ATD) �I 9 Figure No. A-3 Ys n 2Ctconsuttin Ex loration/Test Pit M g Project Number Exploration Number Sheet IN-DEPTH PERSPECTIVE 060159-005 TH-1004 1 of 1 Project Name Mason County DPW Highway 101 Site Ground Surface Elev 313 Location See site plan for location/Shelton,WA Contractor/Method Mason County DPW/ Depth to Water N/A Sampling Method Grab Sample Start/Finish Date 1/4/2007 Depth/ Sample PID Material Depth El (fveati)n Type4D Tests/Remarks (ppm) Type Description (ft) —' TOPSOIL/FOREST DUFF WEATHERED OUTWASH Loose to medium dense,reddish-brown,moist,silty, gravelly,SAND(SM);roots 1 312 1 2 311 N/A 2 0 0 e 0 GLACIAL OUTWASH DEPOSITS 0 3 310 0 Q 0 Dense,gray,moist,sandy GRAVEL,trace silt(GW);with 3 o cobbles;gravel is fine to coarse,sand is fine to coarse 0 0000 4 309 0 0 4 0000 0 o,o, c� 5 308 0000 5 0 00 6 307 0 6 0000 c� O�Op eo 7 306 QO�o 7 0 0000 0 8 0 8 O�OD o � 0 000, N Oo�eO 0 9 304 0 9 o o,00 0000 10 303 10 3 Bottom of exploration at 10 feet. o No groundwater observed,excavation walls standing vertically. z Z' 0 0 o Sampler Type: PID-Photoionization Detector(He dspace Measurement) Logged by: DFR/JAP § ® No Recovery 1 Static Water Level a ® Grab Sample Water Level(ATD) Approved by: JLP Q Groundwater Seepage(ATD) �t C Figure No. A-5 %ASpectconsuttingx loration/Test Pit Project Number Exploration Number Sheet W-DEPTH PEASPECTNE 060159-005 TH-1007 1 of 1 Project Name Mason County DPW Highway 101 Site Ground Surface Elev 311 Location See site plan for location/Shelton,WA Contractor/Method Mason County DPW/ Depth to Water N/A Sampling Method Grab Sample Start/Finish Date 1/4/2007 Depth/ Sample Tests/Remarks PID Material Description Depth Elevation n Type/ID (ppm) Type (ft) TOPSOIUFOREST DUFF WEATHERED OUTWASH Loose to medium dense,dark brown,moist,silty,gravelly, SAND(SM);roots 1 310 1 2 309 N,A , 0° 0 GLACIAL OUTWASH DEPOSITS 2 0 CD 0 0 0 0 Dense,gray,moist,sandy GRAVEL,trace silt(GW);with °o cobbles;gravel is fine to coarse,sand is fine to coarse 0�0� 3 308 0 3 0 o,o, 4 307 0�0 0 4 0 oo o° c� oDoO 5 306 5 0 0000 0 ODOR 6 305 0 ° 6 0000 0 0000 0 0 0° 7 304 7 0 O�OD c� S-1 M o 8 303 8 0 N z 9 302 9 Bottom of exploration at 9 feet. No groundwater observed,excavation walls standing a vertically. c� b 10 301 10 x 3 0 z z 0 0 o Sampler Type: PID-Photoionization Detector(He dspace Measurement) Logged by: DFR/JAP ® No Recovery T- Static Water Level a ®Grab Sample Water Level(ATD) Approved by. J LP Groundwater Seepage(ATD) 9Figure No. A-7 AS eCt Exploration/Test Pit p consulting Project Number Exploration Number Sheet IN—DEPTH PERSPECTIVE 060159-005 TH-1009 1 of 1 Project Name Mason County DPW Highway 101 Site Ground Surface Bev 311 Location See site plan for location/Shelton,WA Contractor/Method Mason County DPW/ Depth to Water N/A Sampling Method Grab Sample Start/Finish Date 1/4/2007 Depth/ PID Material Depth Elevation Sample Tests/Remarks (ppm Type Description (ft) (feet) yp " TOPSOILIFOREST DUFF WEATHERED OUTWASH Loose to medium dense,reddish-brown,moist,silty, gravelly,SAND(SM);roots 1 310 1 2 309 2 N/A GLACIAL OUTWASH DEPOSITS Q o 0 0 Dense,gray,moist,sandy GRAVEL,trace silt(GW); numerous cobbles;gravel is fine to coarse,sand is fine to 3 3 308 ° coarse ODOO Q Q 4 307 4 Q o°o, ODOO Q o,o° ■ DOD 5 306 0 5 °Q OQO� Q 6 305 —6 Q S-1 ° 7 304 7 Q Q 8 303 Q 8 Bottom of exploration at 8 feet. No groundwater observed,excavation walls standing g vertically. N cV z 9 302 9 a c? o_ 10 301 10 3 o z z 0 0 o Sampler Type: PID-Photoionization Detector(Headspace Measurement) Logged by: DFR/JAP ® No Recovery 1 Static Water Level o ® V Water Level(ATD) Approved by: JLP Grab Sample Q Groundwater Seepage(ATD) W 9 Figure No. A-9 %Aspect Ex loration/Test Pit consulting Project Number Exploration Number Sheet IN-DEPTH PERSPECTIVE 060159-005 TH-1011 1 of 1 Project Name Mason County DPW Highway 101 Site Ground Surface Elev 311 Location See site plan for location/Shelton,WA Contractor/Method Mason County DPW! Depth to Water N/A Sampling Method Grab Sample Start/Finish Date 1/4/2007 Depth/ Sample PID j Material Depth Elevation Sample Tests/Remarks (ppm Type Description ep(feet) TOPSOIUFOREST DUFF WEATHERED OUTWASH Loose to medium dense,reddish-brown,moist,silty, gravelly,SAND(SM);roots 1 310 1 2 309 N/A °0, 0 GLACIAL OUTWASH DEPOSITS 2 0 o o Dense,gray,moist,sandy GRAVEL,trace silt(GW);with o cobbles;gravel is fine to coarse,sand is fine to coarse 3 308 Oo 0 3 o,o, 0000 c� O�OD 0 4 307 0°0° 4 0000 c� c� 5 306 5 0 OQOD 0 6 305 6 S-1 �0�0 0 o,o° O 7 304 7 0 ODOR 0 8 303 00 0 8 oQo� 0 N OQ�O N 9 9 0°0 � o O O O 10 301 0 0 10 = Bottom of exploration at 10 feet. oNo groundwater observed,excavation walls standing 0 vertically. z 0 U U o Sampler Type: PID-Photoionization Detector(Headspace Measurement) Logged by: DFR/JAP ® No Recovery 1 Static Water Level a ® Grab Sample Water Level(ATD) Approved by: J LP F Q Groundwater Seepag (ATD) WI 9 Figure No. A- 11 Ys eCt Exploration/rest Pit p consulting Project Number Exploration Number Sheet IN-DEPTH PERSPECTNE 060159-005 TH-1013 1 of 1 Project Name Mason County DPW Highway 101 Site Ground Surface Elev 312 Location See site plan for location/Shelton,WA Contractor/Method Mason County DPW I Depth to Water N/A Sampling Method Grab Sample Start/Finish Date 1/4/2007 Depth/ Sample PID Material Depth Elevation TypeAD Tests/Remarks (ppm) Type Description (ft (feet) ) `` TOPSOILIFOREST DUFF WEATHERED OUTWASH Loose to medium dense,reddish-brown,moist,silty, gravelly,SAND(SM);roots 1 311 1 GLACIAL OUTWASH DEPOSITS c� 2 310 0 o Dense,gray,moist,sandy GRAVEL,trace silt(GW);with 2 N/A o cobbles;gravel is fine to coarse,sand is fine to coarse c� o°o° ODOD 3 309 0° 3 c� o°o, ODOD c� 4 308 0000 4 c� CJ o,o, 5 307 O ODOD c� 6 306 000� 6 c� OQO� CJ 7 305 DOD 7 c� ODOD c� S-1 0D0O 8 304 0° 8 oOOD 0 o,o, N 0 9 303 �D�p 9 o ODOD a � o ODOD 10 302 10 = Bottom of exploration at 10 feet. oNo groundwater observed,excavation walls standing vertically. z 0 U o Sampler Type: PID-Photoionization Detector(Headspace Measurement) Logged by: DFR/JAP ® No Recovery 1 Static Water Level a ® Grab Sample I Water Level(ATD) Approved by. J LP Q Groundwater Seepag (ATD) �t C Figure No. A- 13 . %AspectExploration/Test Pit consulting Project Number Exploration Number Sheet IN-DEPTH PERSPECTIVE 060159 005 TH-1015 1 of 1 Project Name Mason County DPW Highway 101 Site Ground Surface Elev 311 Location See site plan for location/Shelton WA Contractor/Method Mason County DPW/ Depth to Water N/A Sampling Method Grab Sample Start/Finish Date 1/4/2007 Depth! Sample PID Material Elevation TypeAD Tests/Remarks Description Depth (feet) (ppm) Type (ft) { TOPSOIL/FOREST DUFF WEATHERED OUTWASH Loose to medium dense,reddish-brown,moist,silty, gravelly,SAND(SM);roots 1 310 1 2 309 N/A GLACIAL OUTWASH DEPOSITS 2 Dense,gray,moist,gravelly SAND,trace silt(SW);vAth cobbles;gravel is fine to coarse,sand is fine to coarse 3 308 3 4 307 4 5 306 5 6 305 e 0 0 Dense to very dense,gray,moist,sandy GRAVEL,trace 6 p silt(GW);with cobbles;gravel is fine to coarse,sand is o Q o 0 fine to coarse p 7 304 p 7 S-10 00 0 p 00 0, O�OO 8 303 o e 8 CJ o,o, o p N Oe Oo 9 302 p a OQOD � p o,o, s Oyo 10 301 10 3 Bottom of exploration at 10 feet. o No groundwater observed,excavation walls standing vertically. D O U o Sampler Type: PID-Photoionization Detector(Headspace Measurement) Logged by: DFR/JAP ®No Recovery 1 Static Water Level a ®Grab Sample Water Level(ATD) Approved by: J LP WGroundwater Seepag�( T ) Figure No. A- 15 1 Ex loration/Test Pit %Aspectconsulting Project Nu ber Exploration Number Sheet IN-DEPTH PERSPECTIVE 060159- 05 S-1 1 of 1 Project Name Mason County DPW Highway 101 Site Ground Surface Elev 312 Location See site plan for location/Shelton,WA Contractor/Method Mason County DPW/ Depth to Water N/A Sampling Method Grab Sample Start/Finish Date 1/4/2007 Depth/ Sample PID Material Dept Elevation (feet) TypeAD Tests/Remarks (ppm) Type Description (ft) { TOPSOIL/FOREST DUFF WEATHERED OUTWASH Loose to medium dense,reddish-brown,moist,silty, gravelly,SAND(SM);roots 1 311 1 2 310 N/A °0° 0 GLACIAL OUTWASH DEPOSITS 2 c� o Q o Dense,gray,moist,sandy GRAVEL,trace silt(G";with o cobbles;gravel is fine to coarse,sand is fine to coarse 0000 O 0000 0 3 309 �a�o 3 0 O�OO CJ 0000 °p 4 308 0 4 0 0�00 S-1 3 co 0000 0 5 307 CJ o°o, 0000 N O°O° 6 306 O°o° 6 Bottom of exploration at 6 feet. No groundwater observed,excavation walls standing vertically. 3 o_ 0 z 0 0 U o Sampler Type: PID-Photoionization Detector(Headspace Measurement) Logged by: DFR/JAP ® No Recovery 1 Static Water Level IL ® Grab Sample E Water Level(ATD) Approved by: J L P U Q Groundwater Seepa e(ATD) W l Figure No. A-17