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Home My WebLink AboutGEO2012-00011 for BLD2012-00120 - BLD Engineering / Geo-tech Reports - 8/22/2008 I cl c3in I d; - CA I a RECEIVED Mn 0 5 2012 G EOTECHNICAL REPORT 426 W.. CEDAR d� 420 OLYMPIC DRIVE UNION, WASHINGTON PREPARED FOR GARY WRIGHT BY GEOTECHNICAL TESTING LABORATORY, INC. OLYMPIA, WASHINGTOTL A NN ING RECEIVED MAR o e z01Z ;MASON COUNIX AUGUST 221 2008 GROTILCHNICAL TESTING LABORATORY CONTACT INFORMATION PREPARER INFORMATION GTL PROJECT NUMBER: #08-0118 CONTACT: CURTIS D.CUSHMAN ADDRESS: 10011 BLOMBERG STREET SOUTHWEST OLYMPIA,WASHINGTON 98512 TELEPHONE: (360)754-4612 FACSIMILE: (360)754-4848 EMAIL ADDRESS: GEOTESTLAB@COMCAST.NET CLIENT INFORMATION CLIENT: GARY WRIGHT TELEPHONE: (206) 650-8737 BILLING ADDRESS: P.O.BOX 2488 LYNNWOOD,WASHINGTON 98036 SITE ADDRESS: 420 OLYMPIC DRIVE UNION,WASHINGTON 98592 PARCEL: #322345100034 GPS LOCATION: N47o 20' 51.96"W 123'03' 19.81" #08-0118 2 10011 Blomberg Street SW,Olympia,WA 98512 Phone#: (360)754-4612 Fax#: (360) 754-4848 IROTILCHNIC L TESTING LABORATORY SCOPE OF UNDERSTANDING GARY WRIGHT P.O. Box 2488 LYNNWOOD,WASHINGTON 98036 RE: GEOTECHNICAL REPORT 420 OLYMPIC VISTA DRIVE UNION,WASHINGTON 98592 PARCEL#322345100034 N47°20'51.96"W 123,03' 19.81" AUGUST 22,2008 Mr. Wright: As per your request, we have conducted a soils exploration, foundation evaluation, and slope stability analysis for the above-mentioned parcel. The results of this investigation,together with our recommendations, are to be found in the following report. We have provided three copies for your review and distribution. Subsurface samples were submitted for laboratory testing from the project site (H-1). The data have been carefully analyzed to determine soils bearing capacities and footing embedment depths. The results of the exploration and analysis indicate that conventional spread and continuous wall footings appear to be the most suitable type of foundation for the support of the proposed structure. Some variability was encountered in comparing the soil profiles of the site. Net allowable soil pressures, embedment depth, and total expected settlements have been presented for the site later in the report. We are also a full service laboratory that can meet all your building, testing (compaction, asphalt, concrete), and inspection needs. We appreciate this opportunity to be of service to you and we look forward to working with you in the future. If you have any questions concerning the above items, the procedures used, or if we can be of any further assistance please call us at the phone number listed below. o{ Washy Respectfully Submitted, GEOTECHNICAL TESTING LABORATORY LL—lu d/ Engln 243.oiogin`�N, Curtis D. Cushman, L.G., L.E.G. 0 �78ed GepX Senior Engineering Geologist CURTIS DEAN CUSHMAN #08-01 18 3 10011 Blomberg Street SW, Olympia, WA 98512 Phone#: (360)754-4612 Fax#: (360) 754-4848 GrwaawtcAL Ttsnm LABORATORY TABLE OF CONTENTS CONTACT INFORMATION.......................................................................................................................2 SCOPE OF UNDERSTANDING.................................................................................................................3 TABLE OF CONTENTS ..............................................................................................................................4 INTRODUCTION.........................................................................................................................................6 SITECONDITIONS.....................................................................................................................................7 SurfaceConditions ..................................................................................................................................................7 GEOLOGICALLY HAZARDOUS AREAS ................................................................................................8 Landslide Hazard Classification..............................................................................................................................8 Seismic Hazard Classification.................................................................................................................................9 Erosion Hazard Classification.................................................................................................................................9 SiteGeology..........................................................................................................................................................10 SiteSoils................................................................................................................................................................10 SubsurfaceExplorations........................................................................................................................................I 1 SubsurfaceConditions...........................................................................................................................................I I SoilLog.................................................................................................................................................................12 Recommendations for Suitability of Onsite Soils as Fill......................................................................................12 BearingCapacity Analysis....................................................................................................................................13 SlopeStability and Analysis..................................................................................................................................14 Recommendations for Building Setback...............................................................................................................17 LiquefactionHazard..............................................................................................................................................17 SeismicHazard......................................................................................................................................................18 Recommendations for Erosion Control.................................................................................................................18 EARTHWORK...........................................................................................................................................19 Recommendations for Site Preparation.................................................................................................................19 _ Recommendations for Structural Fill ....................................................................................................................19 Recommendations for Cut and Fill Slopes............................................................................................................20 Recommendations for Foundation Support...........................................................................................................20 Recommendations for Floor Slab Support............................................................................................................21 Recommendations for Retaining Walls.................................................................................................................21 MasonCounty Prescribed Wall Design.................................................................................................................23 Recommendations for Retaining Wall Alternatives..............................................................................................25 Recommendations for Site Drainage.....................................................................................................................25 SepticImpact.........................................................................................................................................................25 CONCLUSIONS AND RECOMMENDATIONS......................................................................................26 General...................................................................................................................................................................26 REPORT LIMITATIONS AND GUIDELINES FOR USE.........................................................................................26 References .............................................................................................................................................................27 APPENDIX ....................................................................................................................................................29 BoringLog H-1......................................................................................................................................................30 LaboratoryResults H-1, 5 Feet..............................................................................................................................31 ShearH-1, 10 Feet.................................................................................................................................................32 SieveAnalysis H-1, 15 Feet..................................................................................................................................33 SieveAnalysis H-1, 20 Feet..................................................................................................................................34 SieveAnalysis H-1, 25 Feet..................................................................................................................................35 #08-01 18 4 10011 Blomberg Street SW,Olympia,WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 GEOTECHNICAL TESTING LABORATORY SieveAnalysis H-1, 30 Feet..................................................................................................................................36 Figure1 Vicinity Map...........................................................................................................................................37 WellLog................................................................................................................................................................38 Figure 2 Site Plan Attached Figure 3 Erosion Control Notes Attached Figure 4 Cross-section Attached #08-0118 5 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360)754-4612 Fax#: (360) 754-4848 INTRODUCTION This report summarizes the results of our geotechnical consulting services for the proposed residential building for Mr. Gary Wright. .The site is approximately 2.0 mile east of Union, Washington and is accessed off East Olympic Vista Drive from State Route 106. The GPS location of the site is shown relative to the surrounding area on the Vicini Ma Fi ure 1 at the end of this re ort . v i ..ram Pictures illustrating adjacent slope in the site. Our understanding of the project is based on our discussions with the client and Mason County. We understand that the parcel is to be developed with a single residence unit. In general, grading will consist only of the excavation of the foundation, footings, and utilities. The septic drainfield is proposed and the.location has been depicted in the site plan attached with this report. The approximate layout of the site is shown on the Site Plan, Figure 2. The purpose of our services is to evaluate the surface and subsurface conditions at the site as a basis for providing geotechnical recommendations and design criteria for the project and to satisfy the requirements of the Mason County Critical Areas Ordinance. Geotechnical Testing Laboratory, Inc. is therefore providing geologic and hydrogeologic services for the project. Specifically,our scope of services for this project includes the following: 1. A review of the available geologic, hydrogeological and geotechnical data for the site area. 2. A geologic reconnaissance of the site area and surrounding vicinity. 3. Drilling and sampling. 4. Comparison of site to published geologic maps, previous field investigations, and open file reports. Inspection of aerial photographs to determine the geomorphology of the site. 5. Laboratory grain size and shear angle analysis for the soil samples collected from the site. 6. Evaluation of the landslide, erosion, and seismic hazards at the site per the Mason County Critical Areas Ordinance regulations(December 27,2006). 7. Building setbacks determined from dynamic slope stability modeling. 8. Geotechnical recommendations for site grading including site preparation, subgrade preparation, fill placement criteria (including hillside grading), temporary and permanent cut and fill slopes, drainage and typical erosion control measures(Figure 3). The steepest slope measured onsite was approximately 20 percent throughout the parcel. The steepest offsite slope measured within 300 feet of the parcel is approximately 90%. This steep slope is located beyond the western end of the parcel. 408-0118 6 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 17.01.100E5(1) -- A discussion of general geologic conditions, specific soil types, ground water conditions, the upslope geomorphology and location of upland waterbodies and wetlands, and history of landslide activity in the vicinity. SITE CONDITIONS SURFACE CONDITIONS The proposed building site is located in an area of limited residential development along an upland hillside slope facing to the west at Union, Washington.(See aerial photos below). cam 71 i 1 A reconnaissance was held on April 12, 2008, by Curtis D. Cushman and Travis Harshman. The purpose of a site reconnaissance is to physically observe the property and adjacent properties to identify any recognized geologic conditions. Photographs and visual observations were documented. Site-specific features were mapped. The site was drilled on April 16,2008. The site is predominantly undeveloped and heavily covered with vegetation. The few areas cleared serve as an access into the property. The locations of the proposed building and the septic drainfield system are located on the site plan attached with his report. The site has a predominant western exposure. Site elevations range from approximately 230 to 290 feet. The general topography of the site area indicates that drainage flows toward the west to northwest. Off the property to the west is an incised depression feature which serves as a channel for surface runoff during rainfall events. The site plan is included as Figure 2. No evidence of erosion was detected during our site visit.No surface water flow was observed onsite. No ponding of water was observed throughout the site. Slumping and sloughing were not observed throughout the site. No evidence of deep-seated slope instability was observed onsite. No seeps or springs were observed onsite. The area of potential landslide is heavily vegetated with native trees and shrubs. 408-01 18 7 10011 Blomberg Street SW, Olympia, WA 98512 Phone#: (360)7544612 Fax#: (360)7544848 GEOTECHNICAL TESTING LABORATORY 1 The closest water body to the subject site is Hood Canal located approximately 0.46 miles north. No upland water bodies or wetland features were observed during the site reconnaissance or through the inspection of aerial photographs. The maximum slope onsite is approximately 20 percent. However, immediately west to the parcel, the slopes reach 90%downhill.All slope angles were measured using an inclinometer. There are no mappable landslides in this area. There are no upland water bodies affecting the property. 17.01.100E5(2) -- A site plan which identifies the important development and geologic features. A site plan is attached as Figure 2 Site Plan at the end of this report. 17.01.100E5(13) A site map drawn to scale showing the property boundaries, scale, north arrow, and the location and nature of existing and proposed development on the site. A site plan is attached as Figure 2 Site Plan at the end of this report. 17.01.100E5(3) -- Locations and logs of exploratory holes or probes. A location of the exploratory hole is labeled on Figure 2 Site Plan at the end of this report. 17.01.100E5(4) -- The area of the proposed development, the boundaries of the hazard, and associated buffers and setbacks shall be delineated (top, both sides, and toe) on a geologic map of the site. The area of the proposed development, boundaries of the landslide hazard area are included. The Landslide Hazard Area is limited to the area west to the proposed building site. There is adequate vegetation in the hazard slope. A few setbacks are demarcated on Figure 2 Site Plan at the end of this report. Appropriate geology is labeled on Figure 2 Site Plan. 17.01.100E5(5) -- A minimum of one cross section at a scale which adequately depicts the subsurface profile, and which incorporates the details of proposed grade changes. A cross-section is attached to this report as Figure 4. No further grading is anticipated after the publication of this report, is therefore not known at this time,and thus cannot be detailed on the cross-section. GEOLOGICALLY HAZARDOUS AREAS LANDSLIDE HAZARD CLASSIFICATION The Mason County Critical Areas Ordinance(17.01.100A1)defines a landslide hazard area as: The following shall be classified as Landslide Hazard Areas: #08-0118 8 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 Gaon mic A L T iNes so ToRy a. Areas with any indications of earth movement such as debris slides, earthflows, slumps and rockfalls (see figure F.100). b.Areas with artificial oversteepened or unengineered slopes, i.e. cuts or fills. c.Areas with slopes containing soft or potentially liquefiable soils. d. Areas oversteepened or otherwise unstable as a result of stream incision, stream bank erosion, and undercutting by wave action. e. Slopes greater than 15% (8.5 degrees) and having the following: i. Hillsides intersecting geologic contacts with a relatively permeable sediment overlying a relatively impermeable sediment or bedrock(e.g. sand overlying clay); and ii. Springs or groundwater seepage. f. Any area with a slope of forty percent or steeper and with a vertical relief of ten or more feet except areas composed of consolidated rock. A slope is delineated by establishing its toe and top and measured by averaging the inclination over at least ten feet of vertical relief. The subject site meets the qualification of a landslide hazard area due to the nearby slope (to the west) that is greater than 90 percent and more than 10 feet in vertical height(17.01.100A 1 f). SEISMIC HAZARD CLASSIFICATION The Mason County Critical Areas Ordinance(17.01.102A)defines a seismic hazard area as: 1. Areas susceptible to ground failure including the following: a. Areas with mapped geologic faults until proven inactive; b. Deep road fills and areas of poorly compacted artificial fill; c. Areas with artificially steepened slopes (i.e. old gravel pits); d. Postglacial stream, lake or beach sediments; e. River deltas; f. Areas designated as potential Landslide Hazard Areas; g. Bluff areas; and h. Areas underlain by potentially liquefiable soils 2. The following criteria may be used as a guide by the County to indicate areas that have a higher likelihood of meeting the classification criteria above: a. Areas identified on the Coastal Zone Atlas of Washington, Volume 9, Mason County as Af, Qal, Qa2, Qvc, Qls, Qos and Qp. b. Areas identified on the Mason County Soil Survey Map as having slopes greater than 15 percent. c. Faults identified on "Map Showing Known or Suspected Faults With Quaternary Displacement in the Pacific Northwest", A.M. Rogers, T.J. Walsh, W.J. Kockelman and G.R. Priest, US Geologic Survey, 1996; or described in "Active Faulting Investigations on the Canyon River Fault, Southern Olympic Range, Washington", T.J. Walsh and KG. Neal, U.S. Geologic Survey, 1997. d. Areas underlain by potentially liquefiable soils as shown "Liquefaction Susceptibility Map of Mason County, Washington"by Stephen P. Palmer, Sammantha L. Magsino, James L. Poelstra, Eric L. Bilderback, Derek S. Folger, and Rebecca A. Niggemann, September 2004 This site qualifies as a seismic hazard area because the site is categorized as, "l.f. Areas designated as potential Landslide Hazard Areas." EROSION HAZARD CLASSIFICATION #08-0118 9 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360) 754-4848 GEOTECHNICAL TESTING LABORATORY The purpose of the Erosion Hazard Section (17.01.104A) is to identify areas that present potential dangers to public health and safety, and to prevent the acceleration of natural geological hazards, and to neutralize the risk to the property owner from development activities. Areas in Mason County underlain by soils which are subject to severe erosion when disturbed. Such soils include, but are not limited to, those for which potential for erosion is identified in the Soil Survey of Mason County, USDA Soil Conservation Service, 1960, or any subsequent revisions or additions to this source. These soils include, but are not limited to, any occurrence of River Wash ("Ra') or Coastal Beaches ("Cg') and the following when they occur on slopes 15%or steeper: a. Alderwood gravelly sandy loam ("Ac"and"Ad') b. Cloquallum silt loam ("Cd') c. Harstine gravelly sandy loam ("Hb') d. Kitsap silt loam ("Kc') The soils at the site are mapped as Alderwood gravelly sandy loam (Ad) 30 to 45%. This site meets the technical criteria of an erosion hazard area. SITE GEOLOGY The site is generally situated within the Puget Sound glacial upland. Multiple glacial advances deposited the onsite material. The near surface material was deposited during the most recent Vashon stade(stage)of the Fraser glaciation that occurred between about 9,000 and 11,000 years ago. Weathering and erosion has occurred since. The Geologic Map of Washington — Northwest Quadrant (2002) has mapped the site geology as glacial till deposits(Qgt)of continental glacial origin. The report reads: Till — Unsorted unstratified, highly compacted mixture of clay, silt, sand and gravel, boulders deposited by glacial ice, may contain interbedded stratified sand, silt and gravel. Includes part of the Vashon drift undivided. The Geologic Map of the Shelton 1:100,000 Quadrangle, Washington, by Logan(2003) describes the site geology as late Wisconsinan(Pleistocene)glacial deposits. The till(Qgt)is described as: Qgt Till, late Wisconsinan (Pleistocene)—Unsorted, unstratified, highly compacted mixture of clay, silt, sand, gravel, and boulders deposited by glacial ice of the Puget lobe;gray; may contain interbedded stratified sand, silt, and gravel; sand-size fraction is very angular and contains abundant polycrystalline quartz, which distinguishes this unit from alpine till; cobbles and boulders are commonly striated and(or)faceted; although unweathered almost everywhere, may contain cobbles or small boulders of deeply weathered granitic rock.. SITE SOILS The Soil Survey of Mason County, USDA Soil Conservation Service (1960) has mapped the site soils as an Alderwood gravelly sandy loam, 30 to 45 percent slopes(Ad),at the site. The report reads: 408-01 18 10 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360)754-4612 Fax#: (360) 754-4848 GEOTECHNICAL TESTING LABORATORY The Alderwood soils typically formed from gravelly glacial till. They are described as having good natural drainage. Typically, there is no occurrence of a high water table. Internal drainage is described as medium. An erosion hazard may exist if the vegetation is removed. This generalized mapping does not apply to the variable slopes encountered. We assume some variations of Alderwood are present on-and near-site. This soil will be removed in the immediate area of construction. SUBSURFACE EXPLORATIONS Subsurface conditions at the site were evaluated by drilling and reviewing available well logs. A 30 foot deep drill hole was drilled close to the proposed building site with drilling discontinued after hitting refusal. No seeps, seepage, or springs were observed throughout the site. Groundwater was not encountered at the proposed building location and is beyond the scope of this report(at least 100 feet below ground surface). See the provided well logs in the Appendix. Drinking water will be provided by a community well located offsite. Therefore, no well exist onsite and no well is proposed. Soil logs were field logged (visually) using the Unified Soil Classification System (USCS). The soil logs were recorded by Neil Lorenzo on April 16, 2008. Soil colors were visually determined using the Munsell Soil Color Charts, revised 1992. Due to the onsite cohesionless soils, the Soil Penetrometer (H-4200) by Humboldt Manufacturing Company and the E-285 Pocket Vane Shear Tester by Geotest Instrument Corporation were not employed. Samples were collected by means of the split soon sampler shovel. The samples were sealed in Ziploc bags, labeled, and transported to our soils laboratory. Soil gradations were determined by laboratory test method ASTM D-2487 that utilizes the Unified Soil Classification System. The soils laboratory has the following certifications, accreditations, or qualifications: AASHTO American Association of State highway and Transportation Officials AMRL AASHTO Materials Reference Laboratory A2LA American Association for Laboratory Accreditation ICC International Code Council SUBSURFACE CONDITIONS In general, stiff to dense Alderwood gravelly sandy loam (sandy silty gravel) was observed onsite on surface. Densely compacted silty sand with gravel was encountered while drilling. Specific soils information is contained in the following"Soil Logs" section of the report. Pictures illustrating drill samples at various depths #08-0118 10011 Blomberg Street SW,Olympia,WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 Groundwater was not observed or encountered in test pits or along slope faces. Groundwater seepage or springs were not observed along site slopes. The following logs are taken from the drill hole located at north western corner of the proposed building site. Please also see the drill log at the end of this report. SOIL LOG Soil Log 1 (H -1) 0"—6" Top Soil,Organics and leaves 6"—2' Dark brown silty sand with gravel 2' — 10' Silty sand with Gravel 10'—20' Silty sand with Gravel 20'—30' Silty sand with Gravel The subsurface materials encountered below the Alderwood soils are consistent with Vashon Till(Qgt) RECOMMENDATIONS FOR SUITABILITY OF ONSITE SOILS AS FILL Onsite soils may be considered for use as structural fill if industry standards are satisfied. Fill material requirements are found on page 9-31 of the WSDOT Standard Specifications 2006. In general, the native soils (sand, silt, and gravel) encountered on the site must have less than 10 percent fines (material passing the US No. 200 sieve) to be suitable for use as structural fill. Laboratory analysis of the onsite material indicates that the onsite material sampled may be used as structural fill. However, the wide variety of material onsite warrants further testing to be done before using the material as structural fill. See the laboratory results in the Appendix. #08-01 18 12 10011 Blomberg Street SW, Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360) 754-4848 � t��■y��yy'■�y' �{ ,Q• �v 1 � Lo�l Ec HNICAL U TiNG aoRAToRy BEARING CAPACITY ANALYSIS Based on our laboratory testing conducted on the sample of material collected from subject site, we have calculated the theoretical ultimate bearing capacity. The following Terzaghi formula calculates the ultimate bearing capacity. Using the Figure 6.3, page 173 by Prakash, the bearing capacity factors are determined from the shear angle. Using a factor of safety of three (3), the theoretical maximum bearing capacity is equal to 10024 psf using a shear angle of 37°. See the following spreadsheet calculation. The IBC (Table 1804.2) lists the allowable foundation pressure as 2,000 psf for silty sand with gravel. Terzaghi Equation is given by the following formula: Qd = B (cNc + yDfNq + %2 yBN,,) c Nc Y Df Nq 0.5 Y B Ny 1 60 128 1 52 0.5 128 2 65 Total Bearing Capacity is: 30072 Using a Factor of Safety of 3 10024 c= unit cohesion 1 Y= soil density 128 B =footing width 2 D(f) = depth of footing 1 N ( c ) = bearing capacity factor 60 N ( q ) = bearing capacity factor 52 N (Y) = bearing capacity factor 65 Qd =Total bearing capacity Bearing capacity factors taken from, fig 6.3, Soil Dynamics, Shamsher Prakash, Mc Graw Hill Inc. 1981 #08-01 18 13 1001 1 Blomberg Street SW, Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360) 754-4848 GEOTECHNICAL TESTIM LAIMRATORY SLOPE STABILITY AND ANALYSIS In general, the undisturbed native materials of the site consist of a mixture of variable amounts of sand and gravel with minor silt. These materials are in a dense and cemented condition except where they have been disturbed by weathering activity. No evidence of significant erosion was observed onsite at the time of our investigation. Instability of this nature is typically confined to the upper weathered zone, which may be disturbed and has a lower strength. Raveling and sloughing were not observed along the northwestern slope. As previously discussed, weathering, erosion, and the resultant surficial sloughing and landsliding are natural processes that affect slope areas. Significant weathering typically occurs in the upper 2 to 3 feet and is the result of oxidation, root penetration,wet/dry cycles and freeze/thaw cycles. Over excavation may be necessary to ensure the removal of deleterious material. These processes can be managed and the risk reduced through proper construction of the residence. Erosion control recommendations in the slope and buffer areas are provided in the "Building Setback"and"Erosion Control"sections of this report. Excavation and back filling will occur based on appropriate engineering and earthwork recommendations found in the following "Earthwork" section. �� J Grading in the building portion of the 21 u site should be conducted in accordance ✓ �, Ta ; with geotechnical recommendations 1 provided herein. s The Coastal Zone Atlas, Volume 8, Mason County(MA-7)maps the site as $ ^, Vashon glacial till (Qvt). The slope qkv Ta stability is described as "Intermediate" Scale i:za.000 � s throughout the site. The overall geology is that of the Vashon Till (Qgt). It is so marked on Urs figure 2. — sisters Pt- 5 Resources by Rogers and Walsh t... detailing faults in the Puget Sound were reviewed. There is a Quaternary- age inferred fault trending northeast- southwest through Hood Canal northwest of Union approximately 4 to 5 miles northwest of the property. This geophysical lineament is inferred to be a fault running through upper Hood Canal almost parallel to Highway101 P #08-0118 14 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360)754-4612 Fax#: (360)754-4848 GEOTECHNICAL TESTING LABORATORY in the area. There is no specific danger associated with this fault to the property. No other known faults are mapped in the vicinity of the subject site. 17.01.100E5(6) -- A description and results of slope stability analyses performed for both static and seismic loading conditions. Analysis should examine worst case failures. The analysis should include the Simplified Bishop's Method of Circles. The minimum static safety factor is 1.5, the minimum seismic safety factor is 1.1. and the quasi-static analysis coefficients should be a value of 0.15. Slope stability was modeled using the GeoStudio 2004 program (version 6.20) in both static and dynamic conditions (ca = 0.15). Factors of safety were determined using Bishop's, Janbu, and the Morgenstern-Price methods. The site was modeled using a monolithic layer of cemented gravelly sand with minor silt (see Figure 4 Cross-section). The following values were utilized in the slope model: unit weight of 128 pcf, cohesion of 225 psf, and a shear angle of 37'(see Appendix for shear test results). Since groundwater seepage was not observed, the site was modeled using "dry" or unsaturated conditions. The footings will be founded on undisturbed and unyielding native material; hence,the surficial material was not used in the slope model. The hillside is susceptible to specific deep-seated failure. The static Factor of Safety (FoS) is equal to 1.5 for section "A." Under dynamic loading,the 3328 computations demonstrated that the slope is likewise susceptible to failure and is modeled with a FoS of 1.1. We have thusly modeled the "worst-case" scenario; that is, our slope- stability models show the maximum failure coinciding with the Mason County Requirements of a minimum ov 1.50 and 1.10 for factors of safety. The following figures exhibits the solutions of extreme concern under acceptable factor of safety as designated by Mason County. Under this failure scenario, the static factor of safety and dynamic factor of safety for the slope is 1.50 and 1.10 respectively. The results indicate a safety setback and along with vegetation buffer zone is required for this site. See the site plan, Figure 2. #08-01 18 15 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 GLoTwnNw*L TasTiNG Wright Slope Model Slope A, Static Model FoS 1.50 310 - 290 270 • •. •. • •. 260 •- -- •• •• 250 - 2407 C 230 O 220 - •- a 200 Description:Silty Sand w/Gravel lL t: 128 - 7! 790 WCohesion:225 j 186 Phi:37 170 160 160 14o ,so 120 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 310 Distance(ft) Wright Slope Model Slope A, Dynamic Model FOS 1.10 310 • • • • - • - 290 0 - • •�• • •• ••- • •• 270 • • - • • - 260 • • • •• •• •• 240 • -- -- C 230 • • - p 220 - • - a 210 • - 200 Description:Silty Sand w/Gravel - 10 M* 128 _ 190 Cohesion:225 160 Phi:37 - - 170 160 150 140 130 120 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 Distance(ft) #08-0118 16 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360)754-4612 Fax#: (360)754-4848 17.01.100E5(7) -- Appropriate restrictions on placement of drainage features, septic drain fields and compacted fills and footings, including recommended buffers and setbacks from the landslide hazard areas. The slope models above exhibit under the present grade; a setback from the active land slide hazard area is needed for the proposed construction. There are few drainage problems foreseen,considering the size and location of the lot. The active landslide hazard area is heavily vegetated. The area of landslide hazard has been specified on the site plan. The residence is setback 49 feet to exclude the building from any potential slide damage. Due to the existing vegetation, the type of construction proposed, and the soil erosion classification of this site, a 30 foot vegetation buffer measured from the top of the Landslide Hazard Area is sufficient and recommended. Any larger could impinge directly on the proposed building site. Refer to the site plan attached .The vegetation buffer area should be left undisturbed as much as possible. 17.01.100E5(11) -- Specifications of final development conditions, such as vegetative management, drainage, erosion control, and buffer widths. RECOMMENDATIONS FOR BUILDING SETBACK The building setback may be measured from the footing of the structure to the top of the steep slope in accordance with the International Building Code(1805.3.1), see figure to right. As previously discussed, weathering, erosion and the resultant surficial sloughing and shallow landsliding are natural processes that affect slope ��— areas. Slumping and sloughing were not observed along the various slopes. To manage and reduce the potential for these natural processes, we recommend the following. " No drainage of concentrated surface water or significant sheet flow onto the sloped areas. No filling on the setback zone. Maintain a 30 foot vegetation buffer from the active land slide hazard area. LIQUEFACTION HAZARD The surrounding undisturbed slopes are well vegetated. The absence of springs and seeps along the slope faces and the lack of groundwater encountered during drilling signify that groundwater is at least 60 feet below the ground surface which is also noted in the available well log close to the parcel. Shaking of the already dense glacial till is not apt to produce a denser configuration and subsequently excess pore water pressures are not likely to be produced. Lacking shallow groundwater, the mixed material (gravels, sands, and silts) is well graded and cemented and is not a likely candidate for liquefaction concerns. Grain-size analyses are found in the Appendix. Based on our review of the subsurface conditions, we conclude that the site soils are not susceptible to liquefaction. #08-0118 17 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360)754-4612 Fax#: (360) 754-4848 The Liquefaction Susceptibility Map of Mason County, Washington by Palmer, Magsino, Poelstra, Bilderback, Folger, and Niggemann(September 2004)maps the site area as having a very low liquefaction potential. The Site Class Map of Mason County, Washington by Palmer, Magsino, Bilderback, Poelstra, Folger, and Niggemann(September 2004)maps the site area as site class C. Site class C is a very stiff soil or soft rock. SEISMIC HAZARD According to the Seismic Zone Map of the United States contained in the 2006 International Building Code(IBC), the project site is located where the maximum spectral response acceleration is 45 percent of gravity(g). Based on the subsurface conditions observed at the site, we interpret the site conditions to correspond to a seismic Soil Profile Type C, for very stiff soil, as defined by Table 1613.5.2 (IBC). This is based on probing with a ''/c- inch diameter steel probe rod and drilling results. The shallow soil conditions were assumed to be representative for the site conditions beyond the depths explored. 17.01.100E5(9) Recommendations for the preparation of a detailed temporary erosion control plan which identifies the specific mitigating measures to be implemented during construction to protect the slope from erosion, landslides and harmful construction methods. RECOMMENDATIONS FOR EROSION CONTROL No active surface erosion was observed on or surrounding the subject site. Evidence of ponding was not observed onsite. It is our opinion that the potential erosion hazard of the site is not a limiting factor for the proposed development. Further removal of natural vegetation should be minimized. Yard landscaping around the home is permissible,but native understory growth on the slopes should be encouraged as much as possible as a deterrent to erosion. Temporary and permanent erosion control measures should be implemented and maintained during construction and/or as soon as practical thereafter to limit the additional influx of water to exposed areas and protect potential receiving waters. Erosion control measures should include, but not be limited to, silt fences, berms, and swales with ground cover/protection in exposed areas. Typical erosion control notes and a silt fence detail are included on Figure 2 Site Plan. Any re-contouring of the site will create a need for erosion control measures as recommended above. 17.01.100E5(8) -- Recommendations for the preparation of a detailed clearing and grading plan which specifically identifies vegetation to be removed, a schedule for vegetation removal and replanting, and the method of vegetation removal. The vegetation is removed at the building site, and the landslide hazard area has abundant native vegetation including trees and local shrubs. 408-01 18 18 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 GEOTECHNICAL TESTING LABORATORY ORY 17.01.100E5(12) -- Recommendations for the preparation of structural mitigation or details of other proposed mitigation. No mitigation is required. EARTHWORK RECOMMENDATIONS FOR SITE PREPARATION Based on our observations,we estimate that little additional stripping will be needed. Surficial material that cannot be used for landscaping or erosion control should be removed from the project site. No foundation elements shall be constructed on"untested"fill material. If structural fill is needed,we recommend that a member of our staff evaluate the exposed subgrade conditions. Any soft, loose or otherwise unsuitable areas delineated during foundation preparation or probing should be compacted, if practical, or over-excavated and replaced with structural fill, based on the recommendations of our report. RECOMMENDATIONS FOR STRUCTURAL FILL All fill material should be placed as structural fill. The structural fill should be placed in horizontal lifts of appropriate thickness to allow adequate and uniform compaction of each lift. Fill should be compacted to at least 90 percent of MDD (maximum dry density as determined in accordance with ASTM D-1557) to within 2 feet of subgrade and 95 percent MDD in the upper 2 feet. The appropriate lift thickness will depend on the fill characteristics and compaction equipment used. We recommend that the appropriate lift thickness be evaluated by our field representative during construction. The suitability of material for use as structural fill will depend on the gradation and moisture content of the soil. As the amount of fines (material passing No. 200 sieve) increases, soil becomes increasingly.sensitive to small changes in moisture content and adequate compaction becomes more difficult to achieve. During wet weather, we recommend the use of well-graded sand and gravel with less than 9 percent (by weight) passing the No. 200 sieve based on that fraction passing the 3/4-inch sieve. If prolonged dry weather prevails during the earthwork and foundation installation phase of construction, a somewhat higher(up to 10 percent)fines content will be acceptable. Material placed for structural fill should be free of debris, organic matter, trash, and cobbles greater than 6 inches in diameter. The moisture content of the fill material should be adjusted as necessary for proper compaction. #08-0118 19 10011 Blomberg Street SW,Olympia,WA 98512 Phone#: (360)754-4612 Fax#: (360) 754-4848 GaoTacnNicAL TUTING LABORATORY RECOMMENDATIONS FOR CUT AND FILL SLOPES All job site safety issues and precautions are the responsibility of the contractor providing services and/or work. The following cut/fill slope guidelines are provided for planning purposes. Temporary cut slopes may be necessary during grading operations. As a general guide,temporary slopes of 1.5 to 1 (horizontal to vertical) or flatter may be used for temporary cuts in the upper 3 to 4 feet of the glacially consolidated soils that are weathered to a loose/medium-dense condition. Temporary slopes of 1 to 1 or flatter may be used in the unweathered dense to very dense sands and gravel. These guidelines assume that all surface loads are kept at a minimum distance of at least one half the depth of the cut away from the top of the slope and that significant seepage is not present on the slope face (due to recent rain events). Flatter cut slopes will be necessary where significant raveling or seepage occurs. Surface drainage should be directed away from all slope faces. Straw, hay, or jute matting shall be used to cover the exposed soils until permanent vegetation is established. All disturbed areas should be revegetated as soon as practical to facilitate the development of a protective vegetative cover or otherwise protected. RECOMMENDATIONS FOR FOUNDATION SUPPORT We recommend standard procedures for foundations for a residential home is followed. Where foundation elements are located near slopes between 5 and 30 percent, the footings should be located a minimum of 2 times the footing width from the slope face (horizontally), and founded in medium dense or denser native soils or properly prepared structural fill. We recommend a minimum width for isolated and continuous wall footings to meet IBC 2006. Footings founded as described above can be designed using an allowable soil bearing capacity of 2,000 psf(pounds per square foot) for combined dead and long-term live loads in areas of medium dense to dense soils. The weight of the footing and any overlying backfill may be neglected. The allowable bearing value may be increased by one-third for transient loads such as those induced by seismic events or wind loads. Lateral loads may be resisted by friction on the bases of footings and floor slabs and as passive pressure on the sides of footings. We recommend that an allowable coefficient of friction of 0.40 be used to calculate friction between the concrete and the underlying soil. Active pressure may be determined using an allowable equivalent fluid density of 150 pcf(pounds per cubic foot). We estimate that settlements of footings designed and constructed as recommended will be less than 1 inch, for the anticipated load conditions, with differential settlements between comparably loaded footings of '/z inch or less. Most of the settlements should occur essentially as loads are being applied. However, disturbance of the foundation subgrade during construction could result in larger settlements than predicted. 908-01 18 20 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360)754-4612 Fax#: (360) 754-4848 RECOMMENDATIONS FOR FLOOR SLAB SUPPORT Slabs-on-grade should be supported on medium dense or dense native soils or on structural fill prepared as described in the "Structural Fill" section of this report. We recommend that floor slabs be directly underlain by a synthetic vapor barrier. Below the synthetic vapor barrier, we recommend a minimum 4-inch thickness of coarse sand and/or gravel containing less than 5 percent fines (by weight). The drainage material should be placed and compacted to an unyielding condition. A synthetic vapor barrier must be used for the control of moisture migration through the slab, particularly where adhesives are used to anchor carpet or tile to the slab. A thin layer of sand may be placed over the vapor barrier and immediately below the slab to protect the liner during steel and/or concrete placement. The lack of a vapor barrier could result in wet spots on the slab,particularly in storage areas. RECOMMENDATIONS FOR RETAINING WALLS At this point,no retaining walls are proposed for this development. The following is for completeness. Retaining walls may be utilized on the sloping portion of the site to retain fill material. The lateral pressures acting on the subgrade and retaining walls will depend upon the nature and density of the soil behind the wall. It is also dependent upon the presence or absence of hydrostatic pressure. If the adjacent exterior wall space is backfilled with clean granular, well-drained soil (washed rock), the design active pressure may be determined using an active pressure coefficient equal to 0.25 (Ka = 0.25). This design value assumes a level backslope and drained conditions as described below. Any retaining walls located on site should be designed for a lateral pressure, which includes the surcharge effects of the steep slope in proximity to the wall. Although not expected at this site,the following data are provided for planning purposes. For an irregular or composite slope, the equivalent slope angle may be determined by extending a line upward from the toe of the wall at an angle of 1 to 1 (Horizontal to Vertical)to a point where the line intersects the ground surface. The surcharge effects may be modeled by increasing the equivalent fluid pressure for flat ground by the percentage given in the following table: SLOPE INCLINATION:EQUIVALENT FLUID PRESSURE Slope Angle Percent Increase Equivalent Fluid Pressure Horizontal 0% 35 pcf 3H: IV 25% 44 pcf 2H: IV 50% 53 pcf 1 H: IV 75% 61 pcf If the walls are greater than 4 feet in height, exclusive of the footing, additional design considerations should be applied. Walls greater than 4 feet in height must be designed by a Professional Engineer. Positive drainage, which controls the development of hydrostatic pressure, can be accomplished by placing a zone of coarse sand and gravel behind the walls. The granular drainage material should contain less than 5 percent 908-01 18 21 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 fines. The drainage zone should extend horizontally at least 18 inches from the back of the wall. The drainage zone should also extend from the base of the wall to within 1 foot of the top of the wall. The drainage zone should be compacted to approximately 90 percent of the MDD. Over compaction should be avoided as this can lead to excessive lateral pressures. A perforated PVC pipe with a minimum diameter of 4 inches should be placed in the drainage zone along the base of the wall to direct accumulated water to an appropriate discharge location. We recommend that a non-woven geotextile filter fabric be placed between the drainage material and the remaining wall backfill to reduce silt migration into the drainage zone. The infiltration of silt into the drainage zone can,with time, reduce the permeability of the granular material. The filter fabric should be placed in such a way that it fully separates the drainage material and the backfill, and should be extended over the top of the drainage zone. Lateral loads may be resisted by friction on the bases of footings and as passive pressure on the sides of footings and the buried portions of the wall. We recommend that an allowable coefficient of friction of 0.40 be used to calculate friction between the concrete and the underlying soil. Passive,pressure may be determined by using a passive pressure coefficient equal to 4 (Kp=4). Mason County has provided a prescribed retaining wall design that may be used for non-bulkhead retaining walls less than 4 feet in height. 408-01 18 22 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360) 754-4848 GEOTECHNICAL TESTING LABORATORY MASON COUNTY PRESCRIBED WALL DESIGN MASON COUNTY DEPARTMENT OF COMMUNITY DEVELOPMENT Mason County Bldg.III.426'nest Cedar Street PO Box 1186.Shaft4n.WA 68584 wwrrm.ay.nuwn.wau9 (3W)427-9670 BetFar f36D;k27�-4467 Elena(360)482-52269 UPLAND CONCRETE DesignPrescriptive DESIGN STANDARDS DO NOT APPLY TO SHORELINE EROSION CONTROL BULKHEADS Slope less than or equal to 1:1 S � l s-8ARS -4- -'1---4---'t---� FPZ;VIDE FLOOD 1 I 1 I Fw" CtATINr" 1 1 1 I 1 I t I f I- *-- )) 1'r1EBA•tlrtltlR 1 I 1 i--r --r--- � t1#- 'n- a' AT I$'O.C. -1-4-4--1-4--t--F--I-- r I Ffte'3WC I 1 1 I I 1 I I VZ- SLRFGC�E e' r3t6rJC1 _L_1_1_1_1_1_1_1_ BARSFI"I'- I I 1 1 I I 1 I 1 darl+3C133'C 3C CFre,eC cc-lion. I I 1 I I I 1 I 1 '-'--- 1_ 1_ 1_ , FOatl11CJ6 � --- Beal be \-SHEAR KE'Y°�'na g- paG . �2r6 Gal KNOCKOUT ELEVATION Gal B NOTE; SECTIOra SPACINQ OF S•EMS IS APMC-AINATE.USE TABJLAR N314SER CF W%AND SPACE EVEr+f Y w,?'CC(,/ER s- H E3 T 10L CONC 6AR3 LE�Oi9THE B,B17] REINFORCEMENT FT FT-IN IN '+DS'IFT BQE lPh— 'H-BAFS VZ-RARE SIZE S—C[ LENGTH ! SWE —KM'w: Let PER FOOT 3.6 17 3-- A'E' tp' 6'� — 3.'r 13' 312, 3,B' 12' e-3 17 3.30 1fS 'T 7+4' — 1/2 1C• 31 1T 1 319' 12 11A 11-13 19 U.N. Irz T 2'-1' 1.? A 4w 1= 211' 11' 15.i e •Q 12 BL7 Sw i' - - F-3' SAr 91 91-r 1°, 3w 12' 3e i 408-01 18 23 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 Prescriptive Concrete Retaining Wall DESIGN STANDARD3 Do NOT APPLY To SHORELINE EF4osioN COKYROL BULKHEADS Height:Maximum Eight Feet Upland concrete retaining walls installed in accordance with the prescriptive design shown on the rerveme side need not be designed by an engineer unless the Mason County Building Dept.determines special conditions exist. Any retaining wall exceeding eight feet in height or varying from the prescriptive design requires an engineered design. Location of Retaining Wall Reialning walls must only be placed against stable slopes, consisting of firm,undisturbed soil. Drainage must be provided as shown with a 4'perforated drain pipe or 2'weep holes spaced not less than 12 feet on center. No surcharge load, such as a building or drivcnvay, may be placed on the retaining wall or within a distance equal to the vertical height of the retaining wall unless an engineered design is prtapared for the additional load. Ground Surface Above Retaining Wall The ground surface above the retaining wall shall be less than or equal to 1:1 (i.e. 1-foot vertical to 1-foot horizontal). Retaining Waif Placement The top of the footing for the retaining wall must be set a minimum of 12 inches below grade. The footing and wall dimensions shall not be less than outlined in the retaining wall chart. The footing shall be placed on firm,undisturbed earth. Drainage A minimum of 12 inches of washed granular drainage material shall be placed between the undisturbed soil and the retaining wall. The drainage materials must be composed of gravel with 1-inch particle sizes. Two-inch weep holes shall be located approximately 6-inches above grade, below the granular drainage material, spaced not less than 12-feet on center. At the base of the wal I; a perforated drain pipe,with at least a four-inch diameter,shall be installed within the drainage materials. The drain pipe must drain to a point of discharge,approved by Mason County. Inspections Prior to the placement of concrete.the builder must schedule an inspection of the fonrnrrork and reinforcement placement for the retaining wall footing. During the first inspection,the inspector will verify the soil condition.footing dimensions,footing reinforcement,and footing placement as well as the provisions for drainage. At the next inspection,the inspector shall verify the wall dimensions and reinforcement prior to the wall pour. A final inspection must be performed once all work is complete. To schedule an nspection call the Mason County 24-hour recorded inspection request line at(360)427- 7262. Inspections can also be requested online at:wmv.co.mason.wa.us or by fax at(360)427-7798. When requesting an inspection please provide ttie following informahart: 1) Name on permit 2)type of inspection 3)Permit number 4)Site Address 5)Type of permit 6) Date inspectim requested and 7)Name and phone number of caller. #08-0118 24 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360) 754-4848 GROT YCHNI L TESTING LABORATORY RECOMMENDATIONS FOR RETAINING WALL ALTERNATIVES Typically, block wall systems are more cost effective for long-term walls than the other options. Specific design criteria for these options can be provided at your request by the block manufacturers. RECOMMENDATIONS FOR SITE DRAINAGE All ground surfaces, pavements and sidewalks should be sloped away from the residence and associated structures. Surface water runoff should be controlled by a system of curbs, berms, drainage swales, and/or catch basins and tight-lined into the appropriate drainage facilities. We recommend that conventional roof drains be installed. Footing drains shall be installed for the proposed structure. The roof drain should not be connected to the footing drain. For footing drains,the drain invert should be below the bottom of the footing. Typical drainage control measures are included on Figure 3. Onsite irrigation to lawn areas shall be closely monitored. 17.01.100ES(10) An analysis of both on-site and off-site impacts of the proposed development. SEPTIC IMPACT The proposed septic drainfield is located southeast of the building site. Chapter 246-272A-0210 of the Washington Administrative Code requires a minimal horizontal separation between septic drainfields and various facilities, including footing drains. The proposed drainfield will be located over 50 feet from the landslide hazard area. The proposed drainfield will be located over 20 feet from the proposed building location. We conclude the slope stability of the site will not be adversely impacted by the proposed septic drainfield and the proposed septic drainfield will not be adversely impacted by the landslide hazard area. We also conclude the proposed septic drainfield will not adversely impact the proposed structure. No off site, impacts are expected if the contractor follows the recommendations of this report, Mason County regulations, and approved standards and practices of the industry. #08-01 18 25 10011 Blomberg Street SW, Olympia,WA 98512 Phone#: (360) 754-4612 Fax#: (360) 754-4848 GrEOTEC NICAL TESTING LABORATORY CONCLUSIONS AND RECOMMENDATIONS GENERAL Based on the results of our site reconnaissance, subsurface observations, and our experience in the area, it is our opinion that the site is suitable for the proposed project. The proposed building location is stable relative to deep- seated instability and will not be affected by the proposed structure. The proposed structure will not undermine adjacent slopes. Proper drainage control measures will reduce or eliminate the potential for erosion in this area and improve slope stability. The hazards of the landslide area can be overcome in such a manner as to prevent harm to property and public health and safety, and the project will cause no significant environmental impact for the life of the project. Conventional construction equipment may be utilized for work at the site. A continuous wall footing may be used for this site. Conventional spread footings may be considered for a more permanent foundation. REPORT LIMITATIONS AND GUIDELINES FOR USE We have prepared this report for the exclusive use of Mr. Gary Wright and his authorized agents for the proposed single-family residence in Mason County, Washington. Site inspections, research, and mapping have culminated in this report. This report is intended to meet the requirements of the Mason County Critical'Areas Ordinance. This report does not specify setbacks for: line-of-sight setbacks, FWHCA setbacks, eagle tree setbacks, wetland setbacks, or property line setbacks. Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices in the field of geotechnical engineering in this area at the time this report was prepared. No warranty or other conditions, expressed or implied, should be understood. CONTRACTORS ARE RESPONSIBLE FOR SITE SAFETY ON THEIR OWN CONSTRUCTION PROJECTS Our geotechnical recommendations are not intended to direct the contractor's procedures, methods, schedule or management of the work site. The contractor is solely responsible for job site safety and for managing construction operations to minimize risks to onsite personnel and to adjacent properties. READ THESE PROVISIONS CLOSELY Some clients, design professionals, and contractors may not recognize that the geoscience practices (geotechnical engineering or geology) are far less exact than other engineering and natural science disciplines. This lack of understanding can create unrealistic expectations that could lead to disappointments, claims and disputes. Geotechnical Testing Laboratory includes these explanatory "limitations" provisions in our reports to help reduce such risks. Please confer with Geotechnical Testing Laboratory if you are unclear how these "Report Limitations and Guidelines for Use"apply to your project or site. GEOTECHNICAL,GEOLOGIC,AND ENVIRONMENTAL REPORTS SHOULD NOT BE INTERCHANGED The equipment, techniques and personnel used to perform an environmental study differ significantly from those used to perform a geotechnical or geologic study and vice versa. For that reason, geotechnical engineering or geologic reporting does not usually relate any environmental findings, conclusions or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Similarly, environmental reports are not used to address geotechnical or geologic concerns regarding a specific project. 408-01 18 26 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360)754-4612 Fax#: (360)754-4848 GEOTECHNICAL TESTING LABORATORY REFERENCES MAPS DeLorme 3-D TopoQuads(2002),Source Data USGS,Yarmouth,Maine. Dragovich, Logan, Walsh, and Schasse (2002), Geological Map of Washington-Northwest Quadrant(Geological Map GM- 50),published by Washington State Department of Natural Resources. Logan(2003), Geologic Map of the Shelton 1:100,000 Quadrangle, Washington, (Open file report 2003-15),by published by Washington State Department of Natural Resources. Noble and Molenaar (1970), Geologic Map of Southeastern Mason County, Washington, Water Supply Bulletin 29, Plate 1, Published by Washington State Department of Water Resources Palmer, Magsino, Poelstra, Bilderback, Folger, and Niggemann (September 2004), The Liquefaction Susceptibility Map of Mason County, Washington, published by Washington State Department of Natural Resources. Palmer, Magsino, Bilderback, Poelstra, Folger, and Niggemann (September 2004), The Site Class Map of Mason County, Washington,published by Washington State Department of Natural Resources. Rogers, A. M., Walsh, T. J., Kockelman, W. J., and Priest, G. R. (1996), Map showing known or suspected faults with quaternary displacement in the Pacific Northwest, published by U.S. Geological Survey OFR 91-441-0, Plate 1, scale 1:2,000,000. Smith, Carson (1977), Relative Slope Stability of the Southern Hood Canal Area, Washington, prepared in cooperation with the Washington Department of Natural Resources Division of Geology and Earth Resources; and, Department of the Interior United States Geological Survey. Dragovich, Logan, Walsh, and Schasse (2002), Geological Map of Washington-Northwest Quadrant(Geological Map GM- 50),published by Washington State Department of Natural Resources. Walsh (1997), The Canyon River fault, an active fault in the southern Olympic Range, Washington: Washington Geology, v. 25,no.4,p.21-24,published by U.S.Geological Survey. Washington State Department of Ecology (1979), Coastal Zone Atlas of Washington, Volume 9, published by Washington State Department of Ecology. PUBLICATIONS Ambrose(1981),Simplified Design of Building Foundations,Table 2.5,pages 48-57,published by John Wiley&Sons, Inc. ASTM International(2005),Annual Book of Standards 2005, Section 4, Volume 4.08,published by ASTM International,West Conshohocken, Pennsylvania. Bloom(1991),Geomorphology,published by Prentice-Hall,Inc.,Upper Saddle River,New Jersey. Gallagher, Patricia M. (October 27, 2000), Passive Site Remediation for Mitigation of Liquefaction Risk, Dissertation submitted to the Faculty of the Virginia Polytechnic Institute and State University,Virginia. International Code Council,Inc.(2004),20031nternational Building Code,published by International Code Council,Inc. 408-01 18 27 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360) 754-4848 GROTECHNICAL STING LABORATORY International Code Council,Inc.(2006),2006 International Building Code,published by International Code Council, Inc. Kollmorgen Instruments Corporation (1994), Munsell Soil Color Charts (1994 Revised Edition), published by Macbeth Division of Kollmorgen Instruments Corporation,New Windsor,New York. McCarthy (1993), Essentials of Soil Mechanics and Foundations, published by Prentice-Hall, Inc., Upper Saddle River,New Jersey. Moffit(1992),Surveying 9'h Edition,published by Harper Collins,New York,New York. Ness, Fowler, Parvin(1960),The Soil Survey of Mason County, Washington, USDA Soil Conservation Service, in cooperation with the United States Department of Agriculture, and Washington Agricultural Experimental Station, and the Soils Conservation Service. Parks, Neal, Koloski, Laprade, Molinari, Butler, and Lorentson (November 2006), Guidelines for Preparing Engineering Geology Reports in Washington, published by Washington State Geologist Licensing Board,Olympia,Washington. Prakash(1981),Soil Dynamics,Figure 6.3,page 173,published by McGraw-Hill,Inc. Sowers(1979),Introductory Soil Mechanics and Foundations: Geotechnical Engineering,Table 10:4,page 472,published by Macmillan Publishing Co., Inc. Washington State Department of Transportation (WSDOT) (2005),Standard Specifications for Road, Bridge, and Municipal Construction 2006 M41-10,prepared by WSDOT Engineering Publications,P.O. Box 47408,Olympia, Washington. WEBSITES Mason County Government Information Services (http://www.co.mason.wa.us) Mason County Codes,Ordinances,and Regulations (http://www.co.mason.wa.us/code) Puget Sound Lidar Consortium (http://pugetsoundlidar.ess.washington.edu/lidardata/index.html) Slope Stabilization Erosion Control Using Vegetation,A Manual of Practice for Coastal Bluff (http://www.ecy.wa.gov/biblio/9330.html) Vegetation Management Guide for Puget Sound Bluff Property Owners (http://www.ecy.wa.gov/biblio/9331.html) United States Department of Agriculture Natural Resource Conservation Service (http://soildatamart.nres.usda.gov) Washington Administrative Code (http://apps.leg.wa.gov/wac/) Washington Department of Ecology (http://apps.ecy.wa.gov/weillog) (https://fortress.wa.gov/ecy/coastalatias/viewer.htm) #08-01 18 28 10011 Blomberg Street SW,Olympia,WA 98512 Phone#: (360)754-4612 Fax#: (360) 754-4848 APPENDIX #08-0118 29 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360)754-4612 Fax#: (360)754-4848 GOTCNICAL TESTING LABORATORY BORING LOG H-1 Date:4I16l2008 N 47°20.861'W 123°003.331' File M 08-0113 Boring Log#: 1 Client: Gary Wright Boring Type:Hollow Stem Auger Depth Drilled: 30' Depth Lab Ckmige �Nrc,nt Minus Drillers (ft) Description in Soils %M N Qs Qp V LL FL PI 3f4" ##4 #200 Comments 1 Drak Brown silty sand and gravel 2 Reddish brawn silty sand&gravel 3 4 5 28 6 7 8 9 10 Silty Sand w/Gravel 14.1% 49 98.5% 83.1% 25.1% 11 SM 12 13 14 15 Silty Saud w/Gravel 13.7% 50 97.3% 76.1% 8.1°% 16 SP-SM 17 18 19 20 Silty Sandw/Gravel 11.1% 50 100.0%82.0% 6.5% 21 22 23 24 25 Silty Sand w/Gravel 11.0% 50 88.6°% 71.0°% 7.0% 26 SP-SM 27 28 29 30 Silty Sand w/Gravel 11.4% 50 100.0°%64.0% 6.9% #08-01 18 30 10011 Blomberg Street SW, Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360) 754-4848 GEOTECHNIC. L TESTING LABORATORY LABORATORY RESULTS H-1,5 FEET U.S.Standard Sieve Opening in Inches U.S.Standard Sieve Numbers Hydra meter F'e:�3lts 20 6 4 3 tic :s x h #4 10 16 20 30 40 50 100 200 0% 100% 90% -;.. - - -...... --- - •------------- ----•------------------- ---- 10% 80% ;.. - ....-------------------------- ---------- -------------- 20% 1= 70% - ;.. •-------- -..... ----------------------- ...-..------------------------ 30% 01 60% --,..- ------ -- 40% a1 n m CL 30% -------------;--------------�-------------;---- ---------�-------------:-------------- 70% 20% --------------*-------------�-------------;------ ------Ir-------------;-------------- 80% 10% -------------;-----------------------------;----------- --------:-------------- 90% 0% 100% 1000 100 10 1 0.1 0.101 O.i i01 Grain Size in Millimeters Cobbles Gravels Sands Silts Cla,s Coarse I Fine Coarse Medium I Fine Date : 04115M Did= 0.13 Classification %Gravel Sample#: 514 D30= 0.46 SP-SM,Poorly graded Sand xith Silt and Grave 28.97% Sample ID: Sand with Silt and Gravel D6e= 2.27 Specifications %Sand Source: H-1 Cc= 0.72 No Specs 64.07% Project: Wright,Gary CU. 17.80 %Moisture 11.0% %Silt&Clay Client: Gary Wright Liquid Limit= 0.00 )ust Ratio= 6.96% ASTM#: C-136 Plastic Limit= 0.00 Fineness Moduhu Sample Meets Specs Depth: 25' Plasticity Index= 0.00 3.76 NA Coarse Actual Interpolatedfines Actual Jnterpolated section Cunvilative iCumulative Section Cwnu ative iCurnulative sieve 5zae Percent Fervent .Specs Specs Sieve Si9e ............ :....... .............. Percent i Percent i pees pees US Metric Passing Passing Max Min US Metric Passing Passing Max hour 6.00" € 150.00 1 100.0% #4 4.750 71.0% 71.0% 4.00" 100.00 € 100.0% 1 #8 € 2.360 60.8% 60.8% 3.00" 75.00 € 100.0% #10 2.000 57.5% 2.50" 63.00 [ 100.0% 1 #16 1.180 50.1% i 50.1% 2.00" 1 50.00 100.0% 1 920 0.850 43.5% 1.75" 45.00 1 € 100.0% 1 #30 1 0.600 1 38.5% 38.5% 1.50" 37.50 100.o% 1 100.0% #40 0.425 28.0% 1.25" 31.50 92.7% 92.7% #50 0.300 € 20.5% [ 20.5% € 1,00" 1 25.00 1 90.6% #60 0.250 € 17.4% 1 718" 22.40 89.7% #180 0.180 13.1% 3#4" 1 19.00 1 1 88.6% 1 #100 1 0.150 1 11.3% 1 11.3% 1 518" € 16.00 € 87.6% #140 1 0.106 8.8% € 1/2" [ 12.50 1 86.5% 1 86.5% 1 #170 1 0.090 1 7.8% X8" 1 9.50 82.9°l° 82.9% € 9200 0.075 1 7.0% 7.0% lI4" 1 6.30 1 74.9% #270 1 0.053 1 Copyright;Spear.Engineering&Technical Service,PS,1336.2004 #08-01 18 31 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 GEOTECHNICAL TESTING LABORATORY SHEAR H-1,1O FEET Peak Shear Stress vs. Normal Stress 3000 z6on Shear= 37" zone I W U 1000 i i-114 to 600 •-1l2ton Cohesion =225 psf 0 600 1000 1500 2000 25DD 3000 Normal Stress (psf) #08-0118 32 10011 Blomberg Street SW,Olympia, WA 98512 Phone#: (360)754-4612 Fax#: (360)754-4848 Gconatr,ticAL 7U TwG LAsoRATORY SIEVE ANALYSIS H-1s 15 FEET U.S.Standard Sieve Opening in Inches U.S.Standard Sieve Numbers Hydrometer Results 20 6 4 3 V4 % x `l #4 10 16 20 30 40 50 100 200 0% 100% i 90% �C - �II 1 I 1 0% 80% . .------------------------ ......--------- -------- 20% - 70% --------------- -- 4--------------- -•------------- •------- 30% .cn 1-2 80% ......----- ---.....------ -- •----•----------..------------=-----•--- ---- 40% cn50% --------------------------- ----------- ------------- -------------;-------------- 50% n �rn � 40% -------------i--------------r-------------;-- ----------r-------------r-------------- 60% ,c 30% ----------------------------r-------------;----- --------r-------------;-------------- 70% o 20% ---------------------------- ---------------------- -----f-------------T-------------- 80% 1 I 10% ----------------------------f-------------1------------- ' -------------T-------------- 90% 0% 100% 1000 100 10 1 0.1 0.01 0.001 Grain Size in Millimeters: Gravels S'Uids Silts Clays Co ane I Fine Coarse Mednun Fine Date : 04fl5M D14= 0.10 0"Nification %Grave l Sample#: 512 D36= 0.43 SP-SM,Poorly graded Sand with Silt and Grave 23.93% Sample ID: Sand with Silt and Gravel Dso= 1.89 Sfeci8caltions %Sand Source: H-1 CC= 0.95 No Specs 68.02*4 Project: Wright,Gary Cv. 18.21 %Moisture 13.7% %Silt&Clay Client: Gary Wright Liquid Limit= 0.00 lust Ratio= 8.05°% ASTM#: C-136 Plastic Limit= 0.00 Fineness Modulus Sample Meets Specs Depth: 15' Plasticity Index= 0.00 3.46 NA oamet Actual Jnterpolated fines Actual Jnterpolated Section CusmxlativeiCuaulative Section Curro ative Cumulative 5ieve..S ................I Percent Percent .......Specs.............Specs..... .............5ieve..sue................. Percent Percent Specs " "Specs'" US Metric Passing Passing Max Min US Metric Passing Passing Max Min 6.00" 150.00 100.0% #4 4.750 76.1% 76.1% 4.00" 100.00 € 100.0% #8 E 2.360 64.7% 64.7% 3.00" 75.00 100.0% ? #10 2.000 61.1% 2.50" € 63.00 i 100.0% #16 i 1.180 52.9% 52.9% 2.00" 50.00 100.0°% 1 #20 1 0.850 1 45.5% 1.75" € 45.00 100.0% 1 #30 0.600 39.8% € 39.8% € 1.50" 37.50 100.0% s #40 's 0.425 29.6% 1.25" 31.50 100.0% #50 0.300 22.3% 22.3°% 1.00" 1 25.00 1 100.0% 100.0% ' #60 0.250 1 19.2% 7/8" 22.40 98.8% #80 0.180 i 14.9% € 3/4" 19.00 97.3°l0 97.3°!0 #100 0.150 13.1°% 13.1% 5/8" 16.00 's i 94.7% #140 0.106 i 10.1% lf2" 12.50 1 91.6°% 91.6°% ' #170 0.090 9.1%. 3/8" 9.50 € 88.0°% 88.0% 1 #200 0.075 8.1% 8.1% 1/4" 6.30 80.0% #270 0.053 Copyright;Spears Engineering&Tochnicol Service.PS,1336-2004 #08-01 l 8 33 10011 Blomberg Street SW, Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 GEOTECHNICAL TESTING LABORATORY SIEVE ANALYSIS H-1,20 FEET U.S.Standard Sieve Opening in Inches U.S.Standard Sieve Numbers Hydrurneter Results 00% 20 6 4 3 1.% % " A #4 10 16 20 30 40 50 100 200 0-0.00 0% i 90% - r ...... - - -, - - r..- - -- -- --- 10% i 01 2 of50% -------------I-.-.----------- .------------'-------------- -------------T-------------- 50% n C � ----------- --- 60% 4O% - 1______________f__-----_--_-_1_ ---.--_---__f._.______ T___________ a � as 30% - - -- - - - ----- --------- -------------T- - 70% w 20% -------------i--------------�-------------i------ ------�-------------T- ------------ 80% 10% - - ----------------------------- - --- T - - - 90% 0% 100% 1000 1 iii 1 i i 1 0.1 i 01 0.001 Grain Size in Millimeters isravels Cobbles Sands ilti Clays Coarse Fine Coarse I Medium I Fine Date: 04I15108 D,o= 0.13 Classification %Gravel Sample#: 513 D16= 0.49 SW-SC,Well-graded Sand with Silty Clay and C 18.01 Sample ID: Sand with Silty Clay and Gravel Dao= 1.56 Specifications %Sand Source: H-1 Cc= 1.20 No Specs 75.46'�, Project: Wright,Gary Cv. 12.33 %Moisture 11.1% %Silt&Clay Client: Gary Wright Liquid Limit= 0.00 but Ratio= 6.52% ASTM#: C-136 Plastic Limit= 0.00 Fineness Moduhrs Sample Meets Specs Depth: 20' Plasticity Index= 0.00 3.31 NA Coarse Actual iInterpolated Fixes Actual jinterpolated Section Currailative Cun ulative Section Curmilative`:Cumulative Percent Percent Specs Specs ......... Sieve Sipe Percent Percent Specs Specs ........... .......... Sieve Sipe US Metric i Passing i Passing Max Min US Metric [ Passing Passing Max Min 6.00" 150.00 100.0% 94 4.750 82.0% 82.0% 4.00" 's 100.00 € € 100.0% #8 2.360 72.5% 72.5% 3.00" 75.00 100.0% #10 2.000 € 66.9% 2.50" i 63.00 i 100.0% #16 i 1.180 € 54.0% 54.0% 's 2.00" 50.00 100.0% 920 [ 0.850 43.9% 1.75" 6 45.00 100.0% #30 0.600 € 36.2% 36.2% 1.50" 37.50 100.0% #40 0.425 26.6% 1.25" 31.50 100.0% #30 0.300 193% 19.7% 1.00" 25.00 100.0% #60 0.250 17.0°% ?B" 22.40 € 100.o% [ #80 's 0.180 13.2°% € 314" 19.00 € 100.0% [ 100.0% € #100 0.150 11.6% 1 11.6% SF8" 16.00 98.0% #140 0.106 8.6% lt2" 12.50 95.6% 95.6% #170 ? 0.090 € 7.5% 3J8" i 9.50 92.7% 92.7% #200 0.075 6.5% s 6.5% 1/4" 6.30 85.5% 1 #270 0.053 Copyright;Spear•,Engineering&Technical Services PS,1336-2004 #08-01 18 34 10011 Blomberg Street SW, Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 G-ROTECHNICAL TESTING ]LABORATORY SIEVE ANALYSIS H-1,25 FEET U.S.Standard Sieve Opening in Inches U.S.Standard Sieve Numbers H;hometer Results P _ 20 6 4 3 1% ry x h #4 10 16 20 30 40 50 100 200 0% 100% 90% ;.. - - ---------------------------- - ---------:--------- ---- 10% • 80% ;.. ;------------ -------------- 20% 1= 70% ;.. -.... --------;---------------.....----------:-------------- 30% QL cm 50% -------------i--------------�------------ ;--------------�-------------r-------------- 50% C � 40% ------------- --------------r-------------1-- -----------r-------------T-------------- 60% .c 30% ............................�-------------I---- ---------�-------------r-------------- 70% 20% ---------------------------�-------------;----- ----�-------------T----------- 80% 10% -------------------------- -- ------------T-------------- 90% 0% 100% 1000 110 10 1 0.1 0.01 0.001 Grain Size in Millimeters :r.a rnls Sands t_ohhle Silt_ :-hoe- Coarse Fine Coarse Medium Fine Date : 041l5N8 Dig= 0.13 Classification %Gravel Sample#: 514 D30= 0.46 SP-SM,Poorly graded Sandwith Silt.uid Grave 28.97% Sample ID: Sand with Silt and Gravel Dug= 2.27 Specifications %Sand Source: H-1 Cc= 0.72 No Specs 64.07% Project: Wright,Gary Cu. 17.80 %Moisture 11.0% %Silt&Clay Client: Gary Wright Liquid Limit= 0.00 )wt Ratio= 6.96% ASTM#: C-136 Plastic Limit= 0.00 Fineness Moduhus Sample Meets Specs Depth: 25' Plasticity Index= 0.00 3.76 NA oane Actual 2:Interpolated Actualnterpo to Section C=mlative!Cumalative Section Cumulative€Cumulative breve Srae Percent Percent Specs Specs 5-ii Siae................1 Percent Percent Specs ..Specs US Metric Passirlig Passing Max Min US Metric Passing Passing Max Min 6.00" 150.00 € 100.0°% #4 4.750 71.0°% 71.0% 4.00" € 100.00 i 100.0% M3 2.360 60.8% 60.8% 3.00" 75.00 100.0% #10 2.000 57.5% 2.50" 63.00 [ 's 100.0°l0 #16 I 1.180 50.1°lo i 50.1°I 2.00" 's 50.00 100.0% 1 #20 0.850 43.5% 1.75" 45.00 100.0% #30 0.600 38.5% 38.5% 1.50" 37.50 100.0% 100.0% #40 0.425 28.0°! 1.25" 31.50 92.7% 92.7% #50 0.300 20.5°10 20.5°I 1.00" 25.00 90.6% #60 0.250 17.4% 7/8" 1 22.40 i 89.7% #80 0.180 [ i 13.1% i 3/4" 19.00 s 88.6% #100 0.150 11.3% 11.3% 518" 16.00 87.6% #140 € 0.106 8.8% i 1/2" 1 12.50 86.5% 86.5% #170 0.090 7.8% 3/8" [ 9.50 82.9°% 82.9% #200 0.075 I 7.0% i 7.0% € 114" 6.30 74.9% #270 0.053 Copyright Spear;Enginccring&Technical Service;PS,•1336-2004 #08-0118 3 5 10011 Blomberg Street SW,Olympia,WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 GTECHNIL THING LABORATORY SIEVE ANALYSIS H-1,30 FEET U.S.Standard Sieve Opening in Inches U S,Standard Sieve Numbers Hydrometer Results 100% 20 6 4 3 lk % x 'Au4 10 it, ii:;04i `0 100 200 0% 90% - - ;.. - �..... ;•------------- ..------------;-------------- 10% 80% -- 20% If- 70% - - -•-- .--'•--•-------------------- rn � 60% --- 40% f I i I N 1 r 1 i rn __-_____--_- ' ______---_- ____________ 60% I Z9 30% -------------;-_____________�-------------;__ ________ _________T__________1100% 70% o�¢g S 20% ----------------------------r-------------,------ -------r-------------r---------- 80% 10% -------------=--------------r-------------;----------- -------------T---------- 90% 0% 1000 100 10 1 0.1 0.01 0.001 Grain Size in Millimeters Cobbles Gravels Sands Silts Clays Coarse I Fine I Coarse Medium JFine Date: 04/15108 Dig= 0.13 Classification %Gravel Sample#: 515 Dag= 0.58 SP-SM,Poorly graded Sand with Silt and Grave 35.99% Sample ID: Sand with Silt and Gravel Deg= 3.98 Specifications %Sand Source: H-1 Cc= 0.64 No Specs 57.10% Project: Wright,Gary Cv. 30.41 %Moisture 11.4% %Silt&Clay Client: Gary Wright Liquid Limit= 0.00 hrst Ratio= 6.91% ASTM#: C-136 Plastic Limit= 0.00 Fineness Modulus Sample Meets Specs Depth: 30' Plasticity Index= 0.00 4.03 NA Coarse Actual Jnterpolated flues Actual jInterpolated Section CunnrlativeiCurrwlative Section Cumilative Curmilative Sieve Sipe , Percent Percent Specs -Specs. Sieve Si�e...............� Percent i Percent Specs .Specs US Metric Passing Passing Max Min US Metric Passing Passing Max Min 6.00" 150.00 100.0°I° € #4 4.750 64.0% 64.0% 4.00" 100.00 100.0% € #8 2.360 51.5% 51.5% 3.00" 75.00 100.0% #10 2.000 48.3% 2.50" 63.00 f 100.0% #16 [ 1.180 € 41.0°1° 41.0°l° 2.00" 50.00 € 100.0% #20 0.850 35.2% 1.75" 45.00 [ 100.o% #30 0.600 30.8% 30.8% 1.50" 37.50 100.0% s #40 0.425 23.5% 1.25" 31.50 100.0% € #50 0.300 18.3% 18.3% 1.00" € 25.00 100.0% #60 ' 0.250 i 15.9% 718.. € 22.40 100.0% #80 0.180 12.5% € 314" 19.00 100.0% 100.o% #100 0.150 11.0% 11.0°I° 518" 16.00 96.6% #140 's 0.106 8.6% 1r2" 12.50 92.6% 92.6% #170 0.090 7.7% 3/8" 9.50 80.6°% 1 80.6% #200 0.075 6.9% 6.9% 114" 6.30 69.4% #270 0.053 Copyright;Spear;Enginecrir.q is Technic°I Service.PS,1336.2004 908-01 18 36 10011 Blomberg Street SW,Olympia,WA 98512 Phone#: (360) 754-4612 Fax#: (360)754-4848 GRoTiEciancAL Timm LABORATORY FIGURE 1 VICINITY MAP • I - - J � I #} ' alll ploir 75 i fY •yI I �. N P f'',%�`s/ .+"`"r r.d 1 ,cr t� _., > •-mac-'_ -:� ... / - _- -�, ` .�rf�• FP sryr �Ci�1 �,ti��•�., 'sM'�i �z ��a��y�' d r I� �1..�� :-_� �r ,�^-. �44� fly_ 4- `�. ;fl, �'.i ,i 1S ��...s",.�_. ,f, � ,/ s�/ '?I � ve.�:A'•'' 't-•'.1 ✓,. i a V v "'... .1__ -t, ��, 4 •�/ a I / 7,f j fl S - � �/• j�`�` .'. o Mrs •:.')!t !�I /! 53g14 -1 ti_, 9 G� /� •SOr �� ' / �/I � Jd -~i` c�`�i +f If -� ,l s�yi_.` �;+,�� -� `�2 `�fJ"7�'�� _ l_'-• `�� I � I i •/� ` tip•' t� r J • �' (,._,._v•1 ,�° _� -�; � ,!.� 4J —to--. f t_—, _/ •a. , _..- .� � ��;�,1� J•-. j `'-` -@'�. r �f �Lr�t•_ ems`-' -��l�< ,J SD iapoQrds Cap}rtW C 1999DdAnw Yu=Dwb,DIF OM Sauce Dtts Uscs �1 MD ft Slat 1:2kW L'V1 Dan=nY.M w 408-01 18 37 10011 Blomberg Street SW,Olympia,WA 98512 Phone#: (360)754-4612 Fax#: (360) 754-4848 WELL LOG The Orfpnal and Flnt Copy with WATER WELL REPORT Application 210. .................................. Department of rcobgy T?ilydn CoDYr DOrlfiera CODYy STATi OiR WASfi�1Q'1'ON Permit No. .... 5 (1> OWNER Name �! �� _..._.................._............ 2. U (2) LOCATION OF WELL: counv..... � _....___. -Y. _.t.seoA... TAM-rt.. Baorins and dlatance from section or subdivision corner (3) PROPOSED USE: Domattle ❑ lndnatrtal ❑ Muntelp" (10) WELL LOG: ' Irrigation ❑ Test well ❑ Other 17 For by iM knr a�WU to Ike ktakoi.itun aorilatlu sae Wl�w'iaeh �I atratrea panscraleIL vftfe at&east a" "try for each ch-pe of formation. (4) TYPE OF WORK: (°i"mo a n;a ar)t well xAI>�lAt sRobl To ............. New wall Method:Dug ❑ Bond ❑ +• + . �- C C _ �, ) Deepen ❑ cable ❑ Driv.o Q S' 7 Deepened - Reconditioned[3 Rotary O Rotary❑ - (S) DIMENSIONS: Diameter of ww.......-. _,. .inches. A J 3 ? .2 Depth of complete a well-_ /n O _- Dsiusd.._.!n.....-...2f..-......-tt. (8) CONSTRUCTION DETAILS: ?/J � - CasiaB lastalled:..�.......-Diem.from...t...-/- fL ta ft. -Threaded❑ ........_......"Dlam.tram_.............. ft.to -- Welded❑ _..._.__._.••Dism.tram................ ri.to j Perforations: Yea❑ Noo _ Type of perforator Used. s �- 6IZi at perforations ...._..._--_..._...-._.In.by ................. S ...._.................perforations from......_.....__.._.ft.to.___.____....ri. from__....__...___ft.to ----------.._.... 3 .perforations from.--._......__...._ft.to ft. _ Screens: Yee❑ No`O .�_..-._ .... — Manufseturees Name......___.....____....-._......_._- 5 a DLm. .............._f1Wt else___..._._.nos, _ Dltm ze.................Siot Sim..-.........--?ran rL to ._...__-tL..._........._ 3 - - a se of gravel:...._.._...... Gravel Packed: Yea 0 No fuse _-•-- ft.to_.........._.....---._...__ Orrvel Placed from_._._...__._..._.-......_. - Surface seal: Yes$ Na[� :'a what se depthf... .__..._._. _ !L Material used In al.. .1.� ..... ......._...-_..._......_ f... ....t.Y_._.C .,_1 Did any strata contain unusable water) Yes D N ---- q Type of water?...................._.__._..-Depth of strata......_..._.............-... Il ) 3 (7) PUMP: Msnufactuner's Nanr..._..__..._......_........_............ __ .. ....HP..__._._.__._-._ _ Type: ....._......_........_._.__..._._-_.....--..._.......----_-...... (8) WATER LEVELS: anovas mean Mau�lZal. .. -.c_... ._. ....tt.below top of well fttatle level .__.....(0...!,�....-.._....._. focb ........ Artesian Dre�ure _.-..---_................_.A.. Par aQwn Artesian water is controlled by...............(Cap,vulva,ere.)..._._..._.. _ DrtwdovrR s smorani avatar level it - la&- Compfated-....Q_.__� ..._.....1P (0) WELL TESTS: lowered below static level waft.t++td.__. _.-_. _ Was a pump teat made? Yea❑ No..v if yea.by whom?- ... �. WELL DRILLER'S STATEMENT: 3 Yield: aWmin. wltb it.drawdown after This well was drilled tinder my jurisdiction and this report Is a true to the best of Wily knowled{e and belief. .. turned on) (water 1svY Recovery data (lime taaen as sere when Dump -ttelc .t.'..!.. /�..�.. .............. measured from welt top to water level) NAME._.. �...✓ - --..--...'^"---........ tlpt{ t) L! Tlma orate.f.sDat rims Water I.eua1 rune avatar Latret .-- (passe-erm,oe osrpete > (True prW _.........__..................... / ,F . Addfesg..! _ .�._........ ' ...... .................y....... -..... _.......-._..................- .... -� ............................................ Data of last_...._i£'.�!•-:..... ..�!.-- ..._-... I�sl--•t✓•.._. 'iwau D ..1.. Baler teat_.,,.f7__...salJmtn.with._-.�.(=•.-tt.dnwde..n.ftv__�..___ar.. ) A41 _ / - Arteabn flow----.-._._._._.__------•-._._i.Dm. Dab..-.....-_....__...__---. ---_ i'.)� )) / _ ;� ...... 1.-�.... Temperature of water..._-......-.Was■ehemiesl analysis mad"Yai O 1• License No....::._....... i.... . .. �. __..Date - .. (Uri ADDMONAL seams a N>OCse$ARY) '�a 408-01 18 38 10011 Blomberg Street SW, Olympia, WA 98512 Phone#: (360) 754-4612 Fax#: (360) 754-4848 DATUM FOR THE SITE PLAN INCORPORATED VARIOUS TECHNIQUES AND SOURCES FILTER FABR C MATERIAL SO'WIDE ROLLS INCLUDING THE FOLLOWING: FUSE ABRIC oWREPLES WIRE RING TO ATTACH Geotechnical FABRIC TO WIRE TAPING AND PACING,SLOPE MEASUREMENTS WITH AN INCLINOMETER,ANGLES AND 2'%2 X14 GAUGE WIRE BEARINGS USING A BRUNTONS GEO TRANSIT,SITE LOCATIONS USING A GARMINS HAND FABRIC OR EQUIVALENT HELD OPS UNIT,TOPOGRAPHIC MAPS FROM DELORMES,MASON COUNTY G.I.S.WEBSITE, AND SURVEYS RECORDED AT THE MASON COUNTY ASSESSOR Testing THIS IS NOT AN ACTUAL SURVEY. sd RFADE �, Laboratory r A'MAx LIMIT OF LANDSLIDE HAZARD AREA Z'Xs WOOD POSTS,STANDARD OR BURY BOTTOM OF FILTER BETTER OR EQUAL ALTERNATE: MATERIAL IN B'XI2'TRENCH STEEL FENCE POSTS LIMIT OF 30 FEET VEGETATION BUFFER FILTER FABRICAE Q' 2-AMI4 GAUGE HARE FABRIC OR EQUIVALENT 7 GROU 5-4' II PROVIDE 3/4'-I I?WASHED GRAVEL BACKFILL IN TRENC1? AND ON BOTH SIDES a FIL FENCE FABRIC ON THE SUR 27L4'V-gOD POSTS NORTH ALT:STEEL FENCE POSTS Geotechnical Services SCALE I"•40' FILTER FAWN FENCE NOT!!: QA/QC Services Qgt / C.I.•10, 1.FILTER FABRIC SHALL BE PURCHASED IN A CONTINUOUS ROLL CUT t TO -I THE LENGTH OF THE BARRIER TO AVOID USE OF JOINTS.WHEN JOINTS Testl n/''� Services ARE NECESSARY,FILTER CLOTH SHALL BE SPLICED TOGETHER ONLY AT 9 FASTEN D AT BOTH ENDS TPPORT POST WITH A MINIMUM THP H OVERLAP AND SECURELY 0 10 20 30 1 10 2,POSTS SHALL BE SPACED A MAXIMUM OF 0 FEET APART AND DRIVEN SECURELY INTO THE GROUND(MINIMUM OF 301NCHES). p O 0.A TRENCH SHALL BE EXCAVATED APPROXIMATELY B INCHES WIDE AND/2 10011 Blomberg St.SW 1 INCHES DEEP ALONG THE LINE OF POSTS AND UPSLOPE FROM THE BARRIER. N p g �� Olympia,WA 98512 r O p p p - �]w 4.WHEN STANDARD STRENGTHFILTER FABRIC ISUSED,AWAREME9H Phone:(360)754-4612 V! M p N CV SUPPORT FENCE SHALL BE FASTENED SECURELY TO THE UPSLOPE SIDE r• r� W N N ill" OF THEPOSTSUSINGHEAW-DUTY WARE STAPLES AT LEAST I INCH Fax:(360)754�848 I � LONG,TIE WIRES OR NOG RINGS.THE WIRE SHALL EXTEND INTO THE C� TRENCH A MINIMUM OF 41NCHES AND SHALL NOT EXTEND MORE THAN 30 y INCHES ABOVE THE ORIGINAL GROUND SURFACE. q I S.THE STANDARD STRENGTH FILTER FABRIC SHALL BE STAPLED OR WIRED Date: 05/12/2008 TO THE FENCE AND 20INCHES OF FABRIC SHALL BE EXTENDED Designed by: PL I ^ INTO THE TRENCH.THE FABRIC SHALL NOT EXTEND MORE THAN 30 INCHES ABOVE THE ORIGINAL GROUND SURFACE.FILTER FABRIC SHALL ,J NOT BE STAPABOVE ORIGINALHE ROUNDSTREES. Drawn by: PL /� 8.WHEN EXTRASTRENGTHFILTER FABRIC AND CLOSER POST SPACING IS Checked by: CDC 9 V/I S`- Q USED,THE WIRE MESH SUPPORT FENCE MAP BE ELIMINATED,IN SUCH II ` L`_ a A CASE,THE FILTER FABRIC IS STAPLED OR WIRED DIRECTLY TOTHE Dwg#:05-12-08-032 \\ /ryuy ( •w J 013 ' POSTS WTH ALL OTHER PROVISIONS OR ABOVE NOTES APPLYING. Q Jt Cq ,i (/ 7.FILTER FABRIC FENCES SHALL NOT BE REMOVED BEFORE THE UPSLOPE v 4 + AREA NAS BEEN PERMANENTLY STABILIZED 5,FILTER FABRIC FENCES SHALL BE INSPECTED IMMEDIATELY AFTER EACH Y RAINFALL AND AT LEAST DAILY DURING PROLONGED RAINFALL.ANY REQUIRED REPAIRS SHALL BE MADE IMMEDIATELY. t �J Q9 H- 1 Qg t GENERAL lRDt10N CONTROL NOBS: 1, EROSION CONTROL MEASURES SHALL BE IN PUCE PRIOR TO THE BEGINMNGOFOONSTRUCTION.THE PROJECT ENGINEER AND THE COUNTY SHILL INSPECT AND APPROVE THE INSTALLATION OF Qg(�t ((''�� (�� EROSION CONTROL MEASURES PRIOR TO BEGINNING CONSTRUCTION. A7 POTENTIAL Cd /--.JO 2.EROSION CONTROL MEASURES ARE NOT LIMITED TO THE ITEMS 4 SEPTIC ON THIS PLAN.THE CONTRACTOR IS RESPONSIBLE FOR THE INSTALLATION AND MAINTAINANCE OF ALL EROSION CONTROL MEASURES. LOCATI NO SILTATION OF EXISTING OR PROPOSED DRAINAGE FACILITIES SHALL BE ALLOWED.CARE SHALL BE TAKEN TO PREVENT MIGRATION PROJECT NAME: OF SILTS TO OFF SITE PROPERTIES. 3.THE CONTRACTOR SHALL MAKE DAILY SURVEILLANCE OF ALL EROSION MIGHT SITE CONTROL MEASURESAKEMEASURES ORESNY ESSARY ECONTREPAIRS ACTOR OR SHALL PRONS VIDE 420 OLYMPIC VISTA DRIVE TO THE EROSION ES AND NDL MEASURES.THE CONTRACTOR SHALL PROVIDE j ADDITIONAL EROSION CONTROL MEASURES AS DETERMINED NECESSARY /.' BY THE COUNTY INSPECTOR AND/OR THE PROJECT ENGINEER.FAILURE UNION,WASHINGTON TO COMPLY WITH ALL LOCAL AND STATE EROSION CONTROL REQUIREMENTS MAY RESULT IN CIVIL PENALTIES BEING LEVIED PARCEL 322345100034 AGAINST THE CONTRACTOR AND/OR PROJECT OVMER. 4.DURING THE WET SEASON(NOVEMBER TO MARCH)ALL DISTURBED SOILS SHALL BE STABILIZED WITHIN 48 HOURS AFTER STOP OF WORK EROSION CONTROL MEASURES SHALL INCLUDE,BUT NOT BE LIMITED TO, RBVISI011S, COVERING THE EFFECTED AREA INCLUDING SPOIL PILES WITH Rei J n PLASTIC SHEETING,STRAW MATTING.JUTE MATTING,STRAW MULCH, OR WOOD CHIPS.SEEDING OF THE DISTURBED AREAS SHALL TAKE PLACE AS WEATHER PERMITS. 5.ALL SEEDED OR SODDED AREAS SHALL BE CHECKED REGULARLY TO MAKE SURE VEGETATIVE COVERAGE IS COMLETE,AREAS SHALL BE REPAIRED,RESEEDED,AND FERTILIZED AS REQUIRED. 0.TRACKING OF SOIL OFFSITE WLL NOT BE ALLOWED,IF ANY SOIL IS TRACKED ONTO A COUNTY STREET,IT SHALL BE REMOVED BY THE END OF THAT WORKING DAY.ANY FURTHER TRACKING OF MUD WILL THEN BE PREVENTED BY SWEEPING OR WASHING OF THE VEHICLES TIRES BEFORE DRIVING ON A COUNTY STREET. 7.NO MORE THAN 500 LF OF TRENCH ON A DOWNSLOPE OF MORE THAN 5 PERCENT SHALL BE OPENED AT ONE TIME. 8.EXCAVATED MATERIAL SHALL BE PLACED ON THE UPHILL SIDE OF TRENCHES. 9.TRENCH DEWATERING DEVICES SHALL BE DISCHARGED IN A MANNER THAT WILL NOT ADVERSELY AFFECT FLOWING STREAMS.DRAINAGE SYSTEMS OR OFFSITE PROPERTIES. 10.ALL STORM SEWER INLETS RECEIVING RUNOFF FROM THE PROJECT DURING SCALE:1 inch=40 feet CONSTRUCTION SHALL BE PROTECTED SO THAT SEDIMENT-LADEN WATER WILL BE FILTERED BEFORE ENTERING THE CONVEYANCE SYSTEM. 11,ALL OFFSITE CATCH BASINS IMMEDIATELY ADJACENT TO THE SITE SHALL BE PROTECTED FROM SILTATION. FIGURE 2 12.ALL DISTURBED AREAS SHALL BE SEEDED OR SODDED UPON COMPLETION OF WORK.THE CONTRACTOR SHALL BE RESPONSIBLE TO ENSURE THAT COMPLETE COVERAGE OF THE DISTURBED AREAS IS PROVIDED A THAT GROWTH OF THE VEGETATION IS ESTABLISHED. 13.CATCH BASINS SHALL TRAP O T SEDIMENT OR FILTER FABRIC MUST BE SITE PLAN PLACED UNDER GRATE UNTIL SEDIMENT IS ESTABLISHED. 1/2 INCH MINIMUM DIAMETER STEEL ROD (STRAP)CLAMPED SECURELY TO PIPE CORRUGATED TIGHTLINE 4 INCH MINIMUM,6 INCH SUGGESTED 1 :;aa .� '-i'.?::'::.•.... Fib.i. i�: .?yti.w-3':r:w ;.e.��.v n'�.s:Y III 1p TIGHTLINE ANCHORED WITH TWO, 3 FOOT REBAR LENGTHS OR BOLTS. FLARE END SECTION ��: QUARRY SPALL OR ENERGY � DISPERSION DEVICE =:�'..::'� �'_`s',,�: '�-r�`''-� ;:�,,;.,., ".�j1�•+,;;._ ,:��;'.,' GRASS—LINED SWALE SHOULD BE A MINIMUM ONE FOOT WIDE AT THE BOTTOM AND ONE FOOT DEEP WITH A MAXIMUM SLOPE OF 5 PERCENT. MINIMUM 4 FEET LEVEL SECTION GEOTEXTILE FABRIC Geotechnical Testing Laboratory Geotechnical Services 10011 Bb bGq n.BW FIGURE 3 QA/QC Services O"pia.wn W51z Phone:(360)754-4612 Testing Services Fex:(360)754-4648 Not to scale DRAINAGE DETAILS CROSS-SECTION A (SOUTH-NORTH) PROPOSED 290 HOUSE . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 LOCATION . . .. . . . . . . .. .. . . . . . . . . . . . . . . . . .. . . . . . . . .. . . . . . . ... . . . . . . . . . . . . . .. 270 .. . .. . . .. . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . ... . . . .. . . . . . . . . . . LLY 260 .... . . . . . . . . . ... < .. . . . . ... . . . . . . . .. . . . . . Qgt w 250— _:.. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 240 , z .................0................................................................................................................................ 230 , . . . . . . . . . . . . . . . . .. w 00 220 �. . . . . . . . . . . . . . . . . . . . . . . . . .. . . .. .. .. — 210 t. . . . . . . . . . . 1 LL .. . . ..iu >. . . 0 Qgt . . 200. . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . .. . . . . . . . . .. . . . . . . . . .. . . . . .. .. ...... ....I... .. ...... .. .. .... ... .. .... . .. . 4 190................................ .................................................................................... . ....n X 180 .. . . . . .. . . . . . L . .. . . .. .................................... .................................. .0. . 170.. . . ..Q 160. o . . . . . . . . . . . . .. . . .. . . . . . . . . . .1.0 . . . . . . . .. . . .. . . .. . . . . . . J . . . .. . . .. . . . . . .. . . .. . . . . . . . . . . . . . . . . . . . . .150.. . . . . . . . . . . . Q ................................................................................................. .................. .............................. ......................................................... ...................... . ................... 140—.... .......................................... 130 . . ... . . . . ... . . . . .. . . 120h. . .L1 0 150 1100 150 2700 1250 1300 Geotechnical Testing Laboratory Geotechnical Services 10011 Blomberg St.SW FIGURE 4 Olympia,WA 98512 SCALE QAjQC Services Phone:(360)754-4612 1"=50' CROSS-SECTIONS Testing Services Fax:(360)754-4848 G EO,;&1_2- e7e'0 l� Mason County Review Checklist for a Geotechnical Report Instructions: This checklist is intended to assist Staff in the review of a Geotechnical Report. The Geotechnical Report is reviewed for completeness with respect to the Resource Ordinance. If an item is found to be not applicable, the Report should explain the basis for the conclusion. The Report is also reviewed for clarity and consistency. If the drawings, discussion, or recommendations are not understandable, they should be clarified. If they do not appear internally consistent or consistent with the application or observations on site, this needs to be corrected or explained. If resolution is not achieved with the author, staff should refer the case to the Planning Manager or Director. Applicant's Name: Permit#: ��0 Parcel#: �. f� Date(s) of the Document(s) reviewed: t 08 1. (a) A discussion of general geologic conditions in the vicinity of the proposed development, OK? Comment: (b) A discussion of specific soil types OK? -/ Comment: (c) A discussion,of ground water conditions OK? 1/ Comment: (d) A discussion of the upslope geomorphology OK? ✓ Comment: (e) A discussion the location of upland waterbodies and wetlands OK? Comment: (f) A discussion of history of landslide activity in the vicinity, as available in the referenced maps and records OK? [/ Comment: 2. A site plan that identifies the important development and geologic features. OK? 1 Comment: 3. Locations and logs of exploratory holes or probes. OK? L-- Comment: 4. The area of the proposed development,the boundaries of the hazard, and associated buffers and setbacks shall be delineated (top, both sides, and toe) on a geologic map of the site. OK? Comment: 5. A minimum of one cross section at a scale which adequately depicts the subsurface profile, and which incorporates the details of proposed grade changes. OK? / Comment: 6. A description and results of slope stability analyses performed for both static and seismic loading conditions. Analysis should examine worst case failures. The analysis should include the Simplified Bishop's Method of Circles. The minimum static safety factor is 1.5, the minimum seismic safety factor is 1.1 and the quasi-static analysis coe cents should be a value of 0.15. OK? Comment: j k S' Ar-_el l 7. (a) Appropriate restrictions on placement of rains a features - �/ OK? Comment: aof d'lei �N �1.�6� .��-•�Y_ Sw�/�y� to- `. : �`'j (b) Appropriate restrictions on placement of septic drain fields _ .e_��. OK? Comment: �. c///�r-- — �o f co•,�ev�1 (c) Appropriat strictions on placement of compacted fills and footings. OK? r/ Comment: Page 1 of 2 Form Effective June 2008 i (d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other slopes. OK? ✓ Comment: yrg (e) Recommended setbacks from the landslide hazard areas shoreline bluffs and the tops of other slopes. OK? Comment: 8. for the preparation of a dekiioi�clearing and grading plan which specifically identifies vegetation to be removed, a schedule for vegetation removal and replanting, and the method of vegetation removal. i OK? i,' Comment: 9. Recommendations for the preparation i4f a detailed temporary erosion ntrol plan which identifies the specific mitigating measures to be implemented during construction to pro the slope from erosion, landslides and harmful construction methods. OK? Comment: , 10. An analysis of both on-site and off-site impacts of the proposed development. OK? ✓ Comment: 11. Specifications of final development conditions such as, vegetative management, drainage, erosion control, and buffer widths. OK? ✓ Comment: 12. Recommendations for the preparation of structural mitigation or details of other proposed mitigation. OK? ✓Comment: 13. A site map drawn to scale showing the property boundaries, scale, north arrow, and the location and nature of existing and proposed development on the site. OK? ✓Comment: Are the Documents signed and stamped? 5 By whom? � 5 License#: L Zense type: FIRST REVIEW Approved ❑ Need more info. If not approved, what is)the ext action/recommendation fo further action? fc�° c`'r (`' '', emu, Reviewed by on A Time spent in review: f =7 SECOND REVIEW/ UPDATE ❑ Approved ❑ Need more info. Reviewed by , on . Time spent in second review.- THIRD REVIEW/UPDATE ❑ Approved ❑ Need more info. Reviewed by , on . Time spent in third review: Disclaimer. Mason County does not certify the quality of the work done in this Geotechnical Report. Page 2 of 2 Form Effective June 2008 Mason County Department of Community Development Submittal Checklist For a Geotechnical Report Instructions: This checklist must be submitted with a Geotechnical Report and completed, signed, and stamped by the licensed professional(s)who prepared the Geotechnical Report for review by Mason County pursuant to the Mason County Resource Ordinance. If an item found to be not applicable, the report should explain the basis for the conclusion. Applicant/Owner. Gary Wright Parcel#322345100034 Site Address 420 0i.N NiNic DRINT UNION,WASHINGTON 98592 (1) (a) A discussion of general geologic conditions in the vicinity of the proposed development, Located on page(s) 6& 7 (b) A discussion of specific soil types Located on page(s) 10 (c) A discussion of ground water conditions Located on page(s) 11 (d) A discussion of the upslope geomorphology Located on page(s) 7& 8 (e) A discussion of the location of upland waterbodies and wetlands Located on page(s) 8 (f) A discussion of history of landslide activity in the activity in the vicinity, as available in the referenced maps and records Located on page(s) 8 (2) A site plan which identifies the important development and geologic features. Located on Map(s) Figure 2 (3) Locations and logs of exploratory holes or probes. Located on Map(s) Figure 2 (4) The area of the proposed development, the boundaries of the hazard, and associated buffers and setbacks shall be delineated (top, both sides, and toe) on a geologic map of the site. Located on Map(s) Figure 2 (5) A minimum of one cross section at a scale which adequately depicts the subsurface profile, and which incorporates the details of proposed grade changes. Located on Map(s) Figure 4 (6) A description and results of slope stability analyses performed for both static and seismic loading conditions. Analysis should examine worst case failures. The analysis should include the Simplified Bishop's Method of Circles. The minimum static safety factor is 1.5, the minimum seismic safety factor is 1.1. and the quasi-static analysis coeffients should be a value of 0.15. Located on page(s) 15& 16 (7) (a)Appropriate restrictions on placement of drainage features Located on page(s) 17&25 (b) Appropriate restrictions on placement of septic drain fields Located on page(s) 25 (c) Appropriate restrictions on placement of compacted fills and footings Located on page(s) 19& 20 Page 1 of 2 Form Effective June 2008 Disclaimer: Mason County does not certify the quality of the work done in this Geotechnical Report. (d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other slopes on the property. Located on page(s) 17,figure 2 (e) Recommended setbacks from the landslide hazard areas shoreline bluffs and the tops of other slopes on the property. Located on page(s) 17. Figure 2 (8) Recommendations for the preparation of a detailed clearing and grading plan which specifically identifies vegetation to be removed, a schedule for vegetation removal and replanting, and the method of vegetation removal. Located on page(s) 18 (9) Recommendations for the preparation of a detailed temporary erosion control plan which identifies the specific mitigating measures to be implemented during construction to protect the slope from erosion, landslides and harmful construction methods. Located on page(s) lh (10) An analysis of both on-site and off-site impacts of the proposed development. Located on page(s)25 (11) Specifications of final development conditions such as, vegetative management, drainage, erosion control, and buffer widths. Located on page(s) Covered on points through 7 to 10 (12) Recommendations for the preparation of structural mitigation or details of other proposed mitigation. Located on page(s) None envisioned! (13) A site map drawn to scale showing the property boundaries, scale, north arrow, and the location and nature of existing and proposed development on the site. Located on Map(s) Figure 2 I, Curtis D Cushman hereby certify under penalty of perjury that I am a civil engineer licensed in the State of Washington with specialized knowledge of geotechnical/geological engineering or a geologist or engineering geologist licensed in the State of Washington with special knowledge of the local conditions. I also certify that the Geotechnical Report, dated August 22, 2008, and entitled Geotechnical Report,420 Olympic Drive, Union, Washington meets all the requirements of the Mason County Resource Ordinance, Landslide Hazard Section, is complete and true, that the assessment demonstrates conclusively that the risks posed by the landslide hazard can be mitigated through the included geotechnical design recommendations, and that all hazards are mitigated in such a manner as to prevent harm to property and public health and safety. Wash�' �o h Engineering Geologist 2439 os�sed Gg0 CURTIS DEAN CUSHMAN Page 2 of 2 Form Effective June 2008 Disclaimer: Mason County does not certify the quality of the work done in this Geotechnical Report.