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HomeMy WebLinkAboutGeoTech Report for GRD2007-00025 - GRD Engineering / Geo-Tech Reports - 9/24/2007 t o r 11"E N 6 1 N E E R 1 N 6`._ 1 N C 309 WASHINGTON STREET NE • OLYMPIA WA 98501• TEL:360 352-2477• FAX: 360 352-0179 www.vectorengineeringinc.com September 24,2007 Mr.Robert D.Fink,AICP Mason County—Department of Community Development Mason County Bldg 1 P.O.Box 279 Shelton,WA 98584 Subject: Geotechnical Report,Additional Information Requested Permit#: GRD 2007-00025 Parcel No. 12321-75-00020 Applicant:Bret Schwarz Planner: Chuck McCoy VEI#: 7054-017 Dear Mr.Fink, The geotechnical report dated August 29, 2007 prepared by Envirotech Engineering, 74 NE Hurd Road, Belfair, WA 98528 for a proposed multiple office/industrial buildings along Log Yard Road, Belfair WA 98528 in the SW 1/4 of the NE 1/4 of Section 21, Township 23 North, Range 1 West, Mason County was received on September 21, 2007 and reviewed by Vector Engineering,Inc. As the report is incomplete,we regret to say that we cannot recommend approval of the report. Additional comment regarding the followings items are needed: 1. It is recommended the report be retitled as a Geotechnical Report instead of a Geotechnical Assessment. The special reports are either geological assessments or geotechnical reports. 2. It is recommended that more complete explanation be given why a geotechnical report was done instead of a geological assessment. 3. A 50-foot buffer of undisturbed natural vegetation is required around the Landslide Hazard Area or as recommended by the geotechnical engineer.MCRO 17.01.100 D.6.a. • The landslide hazard area was not identified on the site plan. On the Washington Department of Natural Resources Forest Practices Resource Map, an area of high slope instability was identified on the parcel 4. The report includes a discussion of geologic conditions in the general vicinity, including soil types, groundwater conditions, upslope geomorphology, location of upland waterbodies and wetlands, and a history of the landslide activity. MCRO 17.01.100 E.5. (1). Page 1 of 3 X:\7000 Files\7054 Mason County Geotech Reviews\7054-017 Mason_Co(Schwarz)Wdmin\Transmittal Letters\Gcotechnical Report GRD 2007-00025 Review 1 st request Letter.doc • The report states the site is situated within moderately sloping terrain up to 35%with a vertical relief of about 20 feet. The project is located in the Puget Lowland with sedimentary rocks dominated by glacial drift.No water bodies or wetlands are located upslope. The soil types are a moist,brown silty sand or sand with silt. The NRCS soil type is Indianola loamy sand. No mention was made of any history of landslide activity. 5. The report is to include the locations and logs of exploratory holes or probes. MCRO 17.01.100 E.S.(3). • The locations of the 5 exploratory holes are shown on the site plans. One log of Test Pit Number 3 was provided in the report. The other test pit logs need to be included. i 6. The report is to include a geologic map of the site showing the area of the proposed development with the boundaries of the hazard, and associated buffers and setbacks delineated on the map.MCRO 17.01.100 E.S. (4). • A geologic map of the site showing the area of the proposed development with the boundaries of the hazard, and associated buffers and setbacks delineated on the map was found in the report. The landslide hazard area,buffer,site-or project-specific soil and rock units were not shown on the site plan. 7. The report is to include a cross-section at a scale adequately depicting the subsurface profile.MCRO 17.01.100 E.S.(5). • The cross-section in the report is at a scale adequately depicting the subsurface profile. A building was shown. The retention facility was not shown. The location of the cross-section was not identified on the site plan. 8. The report is to include a description and results of the slope stability analysis. The analysis used the Simplified Bishop's Method of Circles. The minimum static factor of safety is 1.5. The minimum seismic safety factor is 1.1. The quasi-static analysis coefficient should be 0.15.MCRO 17.01.100E.5.(6). • The report states slope stability was modeled using the Simplified Bishop's Method of Circles and ASCE stability charts. The summary did not state the minimum factors of safety. The analysis appears to have been done without the proposed retention pond. The cohesion values of the soil types SPM of 600 psf and SM of 200 psf appear to be high. The unit weight of 140 pcf appears to be also high. Justification is needed for the soil parameters. The summary needs to state the minimum factors of safety. • It is recommended the slope stability analysis be revised to include calculations using the 2003 International Building Code criteria. 9. The report is to include recommendations for the preparation of a detailed clearing and grading plan which specifically identifies vegetation to be removed, a schedule for vegetation and replanting, and the method of vegetation removal. MCRO 17.01.100 E.S. (8)• • The report does include a reference to an erosion/sediment control plan. Recommendations are needed in the report. Page 2 of 3 XA7000 Files\7054 Mason County Geotech Reviews\7054-017 Mason_Co(Schwarz)\Admin\Transmittal Letters\Geotechnical Report GRD 2007-00025 Review 1st request Letter.doc 10. The report is to include recommendations for the preparation of a detailed temporary erosion control plan,which identifies the specific mitigating measures to be implemented. MCRO 17.01.100 E.S.(9). • The report does not directly include recommendations for the preparation of a temporary erosion plan. The only recommendations found in the report were that the removal of natural vegetation is minimized,temporary and permanent erosion control measures should be implemented and maintained, conventional construction equipment may be utilized and that earthwork is undertaken during favorable weather conditions. No general erosion control notes were included in the site plan. 11. The report is to include specifications of final development conditions,such as,vegetative management,drainage control,and buffer widths.MCRO 17.01.100 E.S. (10). • The report includes recommendations for vegetation management and drainage control. No mention was made of buffer widths. We have enjoyed working with you on this geotechnical review to support the goals of the Department of Community Development of Mason County, Washington. We look forward to completing this review when the requested items are provided. Please feel free to contact me if you have any questions regarding these comments, or if you feel any features need further discussion or attention. Sincerely, Russell W. La Force, P.E. Design Engineer Page 3 of 3 XA7000 Files\7054 Mason County Geotech Reviews\7054-017 Mason_Co(Schwarz)\Admin\Transmittal Letters\Geotechnical Report GRD 2007-00025 Review 1st request Letter.doc TO at KEPT IN THE PARCEL FILE Geotechnical Report Bret Schwarz Multiple Office/Industrial Buildings Parcel No. 12321-75-00020 Mason County, Washington October 4, 2007 Project#0726 Prepared For: Bret Schwarz P.O. Box 2305 �,C LYIj� Poulsbo, Washington 98370 G�e�tio� wAS s9 Prepared By: c� Envirotech Engineering 74 NE Hurd R �';' 045 R Belfair, Washington 98528 SIO�rA Phone: 360-275-9374 Fax: 360-275-4789 °CP1HL-s`) (0 009 TABLE OF CONTENTS Page 1.0 INTRODUCTION 1 1.1 Project Description 1 1.2 Purpose of Investigation 1 1.3 Scope of Work 2 2.0 SURFACE CONDITIONS 3 2.1 General Observations 3 2.2 Topography 3 2.2.1 Upslope Geomorphology 3 2.3 Drainage 4 3.0 SUBSURFACE INVESTIGATION 5 3.1 Field Methods 5 3.2 Field Sampling 5 3.3 Field Testing 5 3.4 General Geologic Conditions 5 3.5 Subsurface Conditions 6 3.6 Soils Testing 7 3.6.1 Visual Classification 7 3.7 Infiltration Rates 7 4.0 CONCLUSIONS 8 5.0 ENGINEERING ANALYSIS AND RECOMMENDATIONS 9 5.1 Building Foundation Recommendations 9 5.1.1 Bearing Capacity 9 5.1.2 Settlement 10 5.1.3 Concrete Slabs-on-Grade 10 5.2 Lateral Earth Pressures 10 5.3 Earthwork Construction Recommendations 11 5.3.1 Excavations 11 5.3.2 Placement and Compaction of Native Soils and Engineered Fill 11 5.3.3 Retaining Wall Backfill 12 5.3.4 Building Pads 13 5.4 Slope Stability and Erosion Control 13 5.4.1 Septic Drainfield Impacts 14 5.4.2 Building and Footing Setbacks 14 5.4.3 Erosion Control 14 5.4.4 Surface and Subsurface Drainage 15 5.4.5 Vegetation Considerations 15 5.5 Pavement Analysis 15 5.6 Earthquakes and Liquefaction Potential 16 6.0 LIMITATIONS 17 APPENDIX Appendix A- Site Plan Appendix B - Soil Information Soil Cross-Section Soil Logs Well Reports Appendix C - Slope Stability Appendix D- Geological Map APpa-Jix E - cros;o-, c-,n4rvI 1.0 INTRODUCTION Envirotech Engineering (Envirotech) has completed a geotechnical investigation for multiple building sites on one parcel of land identified as parcel number 12321-75-00020 located in Belfair, Mason County, Washington (Project). As presented herein, this report includes information pertaining to the Project in this Introduction Section; observations of the property and surrounding terrain in the Surface Conditions Section; field methods and soils descriptions in the Subsurface Investigation Section; a brief summary of findings in the Conclusions Section; and, geotechnical recommendations in the Engineering Analysis and Recommendations Section. An initial geotechnical evaluation of the Project was conducted by Envirotech with the owner, Bret Schwarz, on December 6, 2007 with subsequent site visits thereafter. The latest site visit was accomplished on August 20, 2007. It was determined that the southern portion of the parcel have slopes between 15% and 40%, and subsequently will require a geological assessment pursuant to landslide hazard areas of the Mason County Resource Ordinance. Due to the scope of work, and to a lesser extent, proposed features and soil characteristics for this Project, a geotechnical report was deemed necessary in order to provide geotechnical recommendations. These geotechnical recommendations include provisions for the extensive earthwork that is required for this Project, anticipated building loads that exceed typical bearing pressures, and significant stormwater mitigation due to future impervious surfaces. During the evaluation and site visits by Envirotech, surface and subsurface conditions were assessed. After completion of the field work and applicable Project research, Envirotech prepared this geotechnical report. 1.1 Project Information Information pertaining to the Project was provided by the owner. The Project consists of approximately 5.3 acres of land, and will minimally consist of developing five industrial/ office buildings. Anticipated industrial usage includes storage of supplies used in light construction activities. The buildings are planned to be 1- or 2-story, 5000 square feet in size, and some may have daylight basements. Additionally, the development will include septic systems, asphalt paved parking lots, fenced enclosures and areas for storm water mitigation. Potable water access shall be installed from existing water lines located within the utility easement adjacent to the property. Currently, the land is vacant with paved access to the site from Log Yard Road. Log Yard Road is accessed by turning west on Belfair Log Road from State Highway 3, north of Belfair, Washington. 1.2 Purpose of Investigation The purpose of this geotechnical investigation was to evaluate the Project in order to provide geotechnical recommendations relating to the construction of the planned Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 1 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4, 2007 industrial/ office buildings. The investigation included characterizing the general Project surface and subsurface conditions, and evaluating the suitability of the soils to support the planned site development. 1.3 Scope of Work In order to fulfill the purpose of investigation, the geotechnical program completed for the proposed improvements of the Project include: • Review project information provided by the Project owner/developer; • Conduct a site visit to document and photograph the site conditions that may influence the construction and performance of the proposed improvements; • Define the general subsurface conditions of the site by observing five test pit excavations to depths of up to 10 feet below the ground surface within the Project, reviewing well logs of neighboring properties, and shallow probing below the surface;u ace; • Collect bulk samples at various depths and locations, • Perform soils testing to determine selected index properties of the soils that includes 10 visual classifications; • Complete an engineering analysis supported by planned improvements, and the surface and subsurface conditions that were identified by the field investigation and soil testing; and, • Establish conclusions based on findings, and make recommendations for foundations, slope stability, erosion control, earthwork construction requirements, and other considerations. Envirotech Engineering Geotechnical Investigation Ph, 360-275-9374 Page 2 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4, 2007 2.0 SURFACE CONDITIONS Information pertaining to the existing surface conditions for the Project was gathered on May 5, 2007 by Michael Staten, geotechnical engineer with Envirotech. During the site visit, the type of geotechnical investigation was assessed, photographs were taken of the surface and surrounding areas, site features were documented that may influence construction, soil samples were collected from selected locations, and near-surface soils were visually classified. This Surface Conditions Section provides information on general observations, topography, vegetation, and drainage for the Project and surrounding areas that may impact the Project. 2.1 General Observations The Project is currently undeveloped land, with the presence of underground utilities near the northern border of the property and within the utility easement along the northwest property line. The Project consisted of moderate to highly dense vegetation, including firs, madronas, scotch broom, grasses, and other trees and shrubbery common to this area of the Pacific Northwest. Log Yard Road borders the east property line with developed and undeveloped land beyond. Developed land exists to the north of the Project, and undeveloped land exists immediately to the west and south of the property. Observations of surface conditions relating to slope conditions can be found in the Slope Stability and Erosion Control Section of this report. 2.2 Topography The parcel of land is situated within moderate sloping terrain of up to 35% on the southern portion of the property with a vertical relief of about 20 feet. These slopes descend in a southeast direction from inside the west property line to Log Yard Road. Site grades range from slightly sloping to relatively flat within the remaining property limits. Off-site ascending and descending slopes within 300 feet of the property appear to have lesser gradients than those exhibited on-site. See the Site Map in Appendix A for an illustration of the general topography with respect to the planned development. 2.2.1 Upslope Geomorphology Ascending grades located to the west of the Project are generally 15% or less. There are no local water bodies or wetlands located upslope from the proposed development. Envirotech Engineering Geotechnical Im-estigation Ph. 360-275-9374 Page 3 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4. 2007 2.3 Drainage Stormwater runoff originating upslope from anticipated building locations are expected to be very minimal or none at all due to the existing topography. Stormwater drainage within the project will be accounted for in the stormwater grading and drainage plan. Currently, stormwater primarily sheet flows in a southeast direction, and along Log Yard Road. Water is directed to Log Yard Road before crossing onto the adjacent vacant land near the southeast portion of the property. During the site visit, running water was not present within 300 feet of the Project. Excessive scour, erosion or other indications of past drainage problems were not observed at or near the Project. Overall, the earth near the Project surface consists of high permeable soils that is an engineering property conducive of fast groundwater drainage. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 4 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4, 2007 3.0 SUBSURFACE INVESTIGATION Information on subsurface conditions pertaining to the Project was gathered on May 5, 2007 by Michael Staten, geotechnical engineer with Envirotech. Specific information on field methods, sampling, field testing, subsurface conditions, and results from soil testing are presented in this section of the report. 3.1 Field Methods Information on subsurface conditions for the Project was accomplished by observing five excavations extending to depths of up to 10 feet below the existing ground surface. Additional information on subsurface conditions was collected by field testing, shallow probing near expected building pad areas, and reviewing well reports originating from near the subject property. General slope stability maps for the Project and surrounding areas were not available. Appendix B has pertinent information on subsurface conditions for the Project, including a test pit log that is representative of the near-surface soils within the Project and one water well report. 3.2 Field Sampling One bulk sample was collected at the Project site at approximately 2.0 feet below the existing ground surface. The soil sample collected was secured and transported for possible laboratory testing. 3.3 Field Testing Relative density of the in-situ soils were acquired by recording the resistance from driving a '/2" steel bar into the site soils at several locations, and observing the resistance of the excavator during the subsurface exploration. These results generally indicated medium to dense soils to depths of up to 7 feet below the ground surface, and dense soils at depths beginning at 7 feet to 8 feet below the existing ground surface. 3.4 General Geologic Conditions In general, soils at the project are composed of materials from glacial advances. The geologic conditions as presented in the "Geologic Map of Washington," compiled by J. li -P 1 o n IT . Lower tertiary Eric Schuster, 2002 indicates Lower Tertiary (O gocene a e ce e), are generally sedimentary rocks, and dominantly deposited from glacial drift, including Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 5 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason Countv, Washington October 4, 2007 alluvium deposits. This project is located within the Puget Lowland. Typically, "lower tertiary sedimentary rocks unconformably overlie the Crescent Formation." as revealed in the Geologic Map. Initial sedimentary rocks were formed from shales, sandstones and coal deposits from rivers. During the Quaternary period, the Puget Lowland was covered by numerous ice sheets, with the most recent being the Fraser glacier with a peak of approximately 14,000 years ago. Upon the glacial retreat, the landscape was formed by glacial erosion glacial drift deposits. 3.5 Subsurface Conditions The Project subgrade within the depth of penetration at all testing, sampling and observed locations were composed of native soils (no indications of borrowed fill). For engineering purposes, these native soils consist of distinguishable layers, as presented below. Soils below the upper 4 inch to 10 inch organic/ soil mixture to depths ranging from approximately 3 feet to 5 feet below the existing ground surface consists primarily of a moist, brown silty sand or sand with silt (SM / SP-SM) with only traces of gravel. Sands are primarily fine with some medium grain size. The fines content is primarily a silt with none to very low plasticity. These soils were observed and tested to be medium dense to dense. generally consisted of a dense moist aforementioned silty sand , The soils below the of ty g Y brownish/gray poorly-graded sand (SP)with gravel, few silts and few cobbles. These soils extended to depths ranging from 7 feet to 10 feet below the existing ground surface. Gravels were primarily coarse and subrounded, sands were mostly fine and medium, and the silts exhibited none to very low plasticity. In 2 of the 5 test pits, denser soils were encountered at 7 feet and 8 feet below the ground surface. These soils were classified as a sand with silt and gravel (SP) and some cobbles. mostly due to the amount of cobbles at this depth. The denser soils appeared to be y P Subsurface explorations in the field did not extend beyond 10 feet in depth. Below the dense silty sand with gravel soils is expected to consist of dense sand and gravel soils to depths extending beyond 90 feet below the ground surface. Neither permanent groundwater nor bedrock was encountered during the field exploration. Permanent groundwater is expected to be approximately 60 to 90 feet below the existing ground surface beneath proposed building locations. According to well water reports near the project, saturated conditions existed at least 60 feet below the ground surface. According to the U.S. Department of Agriculture Textural Classification System, the Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 6 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4, 2007 upper 10 feet of soils for this Project consisted basically loamy fine/ medium sand, and fine/medium sand. 3.6 Soils Testing The soil samples obtained at the Project site during the field investigation were preserved and transported for specific laboratory testing. Visual classification of soils was performed in the field. The following soil tests were performed in accordance to the American Standards for Testing and Materials(ASTM): • 14 Visual Classifications(ASTM D2488). 3.6.1 Visual Classification The general results from the visual classification are presented in the aforementioned Subsurface Conditions Section extending to depths of 10 feet below the existing ground surface. Minor variations observed during the visual classification of particle size content (i.e. gravel, sand, fines), or isolated pockets within the soil stratification were insignificant in relation to the engineering properties of the soil. 3.7 Infiltration Rates According to the 1992 Stormwater Management Manual for Western Washington prepared by the Washington State Department of Ecology Water Quality Program, infiltration rates of the soils encountered for this Project are the following: • Sand: 4.1 inches/hour • Loamy Sand: 1.2 inches/hour The above infiltration rates take into account a reduction of'/2, as recommended by the stormwater manual. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 7 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4, 2007 4.0 CONCLUSIONS The services described in this report were prepared under the responsible charge of Michael Staten, a professional engineer with Envirotech. Michael Staten has appropriate education and experience in the field of geotechnical engineering in order to assess landslide hazards, earthquake hazards, and general soil mechanics. The Coastal Zone Atlas is not applicable to this Project. However, a detailed analysis of slope stability is presented in the Engineering Analysis and Recommendations Section of this report. There are no apparent indications of landslide activity, modified slopes or concerns from the slope stability analysis. This is based on observations during the surface investigation, and an engineering analysis of the slopes using expected subsurface conditions and anticipated site development as presented in this report. The frost penetration depth is not expected to extend beyond 12 inches below the ground surface for this Project under normal circumstances and anticipated design features. The soils on-site have low to moderate frost susceptible characteristics and may be used to the extents provided in this report. The planned site development will be on moderate sloping terrain. Proper drainage provisions should be implemented where practical, including the recommendations herein in order to reduce the potential for damaging erosion or scow. Off-site impacts due to the expected development of this Project are not anticipated to be of significance. It is our opinion that slopes on and near the Project are sufficiently stable for the development if the recommendations presented in this report are adhered to. In addition, sedimentation control should be adequate when utilizing the erosion control recommendations as presented herein together with implementing appropriate erosion controls with the degree of care as expected from a licensed contractor. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 8 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4, 2007 5.0 ENGINEERING ANALYSIS AND RECOMMENDATIONS The following sections present engineering analysis and recommendations for the proposed improvements of the Project. These recommendations have been made available based on the planned improvements as outlined in the Introduction Section of this report; general observations of drainage and topography as summarized in the Surface Conditions Section; and, soil conditions that were identified by the field investigation and soils testing in the Subsurface Investigation Section. Engineering analysis and recommendations for the Project that is provided herein, includes pertinent information for foundations, settlement, slope stability, earthwork construction, concrete slabs-on-grade, lateral earth pressures, pavements, footing setbacks, surface and subsurface drainage, and erosion control. 5.1 Building Foundation Recommendations Recommendations provided in this section account for the site development of at least 5 two-story commercial buildings. Below the upper 12 inches of native soil within the Project, there is apparently two distinguishable layers of soil that will influence the bearing capacity and settlement of the residential structure. The recommended allowable bearing capacities and settlements as presented below, consider the probable type of construction as well as the field investigation results by implementing practical engineering judgment within published engineering standards. Evaluations include classifying site soils, and deriving probable relative densities, unit weights and angles of internal friction of the in- situ soils based on observed field conditions and soil testing for this Project. 5.1.1 Bearing Capacity For the existing site conditions, bearing values should increase with depth. Existing in-situ soils at the Project site indicates that the structures can be established on shallow, continuous or isolated footings. Foundations shall be established on relatively undisturbed native soil. Alternatively, foundations may be constructed on selective re-compacted native soil or compacted engineered fill as described in the Earthwork Construction Recommendations Section of this report. Footing width and depth recommendations shall be adhered to, and are based on a 2500 pounds per square feet(psf)maximum structural bearing pressure. For a bearing capacity requirement of no more than 2500 psf, a minimum of 24- inch wide footings shall be placed at a minimum of 12 inches below the final ground surface. These recommendations are made available based on adherence to the remaining recommendations that are provided in this report. If structural bearing pressures less than 2500 psf are expected, Envirotech may be contacted to revise these recommendations. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 9 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4, 2007 5.1.2 Settlement Total and differential settlement that a structure will undergo depends primarily on the subsurface conditions, type of structure, amount and duration of pressure exerted by the structure, reduction of pore water pressure, and in some instances, the infiltration of free moisture. Based on the expected native soil conditions, and construction abides by the recommendations in this report, the assumed foundation system may undergo a maximum of 1.0 inch total settlement, and a maximum differential settlement of 0.75 inch. 5.1.3 Concrete Slabs-on-Grade Interior slabs should be supported on a minimum of 4 inches of compacted granular material that is placed over undisturbed native subgrade or engineered fill. Native soils found at the Project site is suitable material for supporting concrete slabs in heated structures. Although not required for the structural integrity of the concrete slab-on-grade, a vapor barrier may be utilized for damp-proofing. If vapor barriers are used, it is recommended to utilize a barrier that is sufficiently thick to resist puncturing during construction, or place a 2 inch layer of sand above the barrier prior to placing the concrete slab. 5.2 Lateral Earth Pressures Stem walls may be planned for structural lower levels, which in some degree, will function as retaining walls. The lateral earth pressures exerted through the backfill of a retaining wall are dependent upon several factors including height of retained soil behind the wall, type of soil that is retained, degree of backfill compaction, slope of backfill, surcharges, hydrostatic pressures, earthquake pressures, and the direction and distance that the top of the wall moves. Lateral earth pressures are anticipated to be at-rest for this particular rigid concrete wall construction. Retaining walls should be designed to resist a lateral earth pressure based on an equivalent fluid unit weight of 50 pounds per cubic foot(pcf) for structural backfill, and 70 pcf for re-compacted native soils used as backfill. These values shall be increased by one pcf for each degree of backslope inclination behind the retaining structure. See the Earthwork Construction Recommendations Section for details concerning engineered fill and placement of backfill. Lateral earth pressure recommendations are based on the foundation depth not exceeding 4 feet below the final ground surface, and the backfill conforming to the compaction requirements provided in the Earthwork Construction Recommendations of this report. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 10 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4, 2007 5.3 Earthwork Construction Recommendations Founding material for building foundations may consist of undisturbed native soils, compacted engineered fill, or selective re-compacted native soils. The following earthwork construction recommendations include excavations, subgrade preparation, type of fill, and placement of fill. The earthwork construction recommendations as presented herein, pertain to construction over the entire 5.3 acres of this Project. 5.3.1 Excavation Excavation is recommended to achieve appropriate foundation depth, and to remove any excessive organic content or other deleterious material, if present, beneath foundations. All soils below the bottom of the excavation shall be relatively undisturbed. If these soils are disturbed, re-compaction is necessary. Excavations shall be completely dewatered before placement of additional native soil, engineered fill or concrete. 5.3.2 Placement and Compaction of Native Soils and Engineered Fill for Foundations For engineered fill or disturbed native silty sand and sandy soils that will be utilized as fill material directly beneath foundations, the following placement and compaction requirements are necessary. Both engineered fill and native soils used as compacted fill should be free of roots and other organics, rocks over 6 inches in size, or any other deleterious matter. Engineered fill should consist of at least 65%-100% gravel-sized material, and less than 5%fines(particles passing#200 sieve)by weight. Compaction of these materials shall be achieved in compacted lifts not to exceed 8 inches and 12 inches for native soils and engineered fill, respectively. Each lift should be uniformly compacted to at least 95% of the modified Proctor maximum dry density (ASTM D 1557). Each lift surface should be adequately maintained during construction in order to achieve acceptable compaction and inter-lift bonding. If clean, coarse gravel soils are utilized as engineered fill, compaction may be achieved by an experienced contractor through reasonably densifying granular soils with water and heavy construction equipment. For compacted or re-compacted fill beneath foundations, the limits of compacted fill should extend laterally from the bottom edge of the foundation at a rate of two feet for each foot of compacted or re-compacted fill beneath the foundation. See the illustration below. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 11 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County,Washington October 4, 2007 A FOOTING C❑MPACTED ENGINEERED FILL I UNDISTURBED SUBGRADE 5.3.3 Retaining Wall Backfill Backfill should consist of engineered fill, native soils or borrow materials approved by a geotechnical engineer. Compaction of these materials shall be achieved in compacted lifts of about 12 to 24 inches. Each lift should be uniformly compacted to no more than 85% of the modified Proctor maximum dry density (ASTM D 1557). Over-compaction should be prevented since this will cause lateral earth pressures to increase, which may be detrimental to the retaining structure. If clean, coarse gravel soils are utilized as engineered fill, compaction may be achieved from a sufficiently experienced earthwork contractor by reasonably densifying granular soils with construction equipment. Backfill for the retaining wall should extend vertically from the top of the footing to the proposed ground surface. At the ground surface, backfill should extend horizontally from the face of the retaining wall to at least 2 feet in back of the wall. Perforated foundation drains for retaining walls should have a 4- inch minimum diameter and direct water as recommended in the Surface and Subsurface Drainage Section of this report. Coarse, clean gravel is recommended to be placed at least 12 inches around the drain pipe in order to provide increased drainage capabilities. Non-woven geotextile filter fabric should be wrapped around the aforementioned coarse gravel for reducing the potential of silt migration and clogging of the drain pipe. See the illustration below. P FT MIN WATER PROOFING BACKFILL 4 FT MAX YNON-WOVEN GE❑TEXTILE IN R❑CK G IN MIN N DIA. PERFORATED PIPE 6 IN MIN Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 12 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason Countv, Washington October 4, 2007 5.3.4 Building Pads Building pads, if utilized for this Project, shall be constructed per the fill placement and compaction recommendations as presented above. Both engineered fill and native soils may be used for building pads. Building pad slopes shall be no steeper than 1:1 for compacted engineered fill, or 1:2 for re-compacted native soils used as fill. Building pad fill in excess of 5 feet, benching will be required at increments of every 5 feet of fill depth. A setback of 5 feet shall be maintained between the building face and the top of the building pad slope. 5.4 Slope Stability and Erosion Control Landslides and erosion are natural processes, and structures near slopes possess an inherent risk of adverse settlement, sliding or structural damage due to these processes. These risks cannot be eliminated for any site with moderate to steep sloping grades. Geotechnical engineering provides an acceptable factor of safety for building near sloping site conditions. These factor of safeties are based on engineering judgment, and engineering standards accumulated from years of academic and professional research by individuals in the field of geotechnical engineering. Surface sloughing or other types of surficial slope movements usually do not affect the deep-seated structural capability of the slope. However, excessive and/or repeated surficial slope movements, if not repaired, may represent a threat to the structural integrity of the slope. With appropriate drainage and erosion control provisions for this Project during and after construction, it is unlikely that this Project will experience excessive surficial movements. However, maintenance of the slope must be completed if the situation does arise in order to prevent the possibility of further surficial or deep seated slope movements that may be damaging to life and property. The buildings for this Project are expected to be situated on a relatively flat grade and moderately sloping grades. During the site visit, there were no indications of deep-seated slope or surficial slope failures. Although the slope grades that exist on-site signal a potential landslide or erosion hazard area, indications of past landslide or current slope failures were not observed. Landslide indicators (none observed on-site) include: • Outwash of sediments near the bottom of the slope, • Fissures, tension cracks or naturally stepped land masses on the face or top of the slope, and parallel to the slope, • Fine, saturated subsurface soils, • Old landslide debris, • Significant bowing or leaning trees, or, • Slope sloughing or calving. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 13 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4, 2007 The Simplified Bishop Method was used to analyze the stability of the Project's slopes utilizing expected site soils, topography, surcharges from expected site improvements, and various slip surfaces. Anticipated building loads, building pad loads, building pad cuts, or impacts from the planned septic drainfield and retention areas are not expected to have any significant influence on the global stability of the slopes, provided that the setback requirements and recommendations in this report are adhered to. Based on the aforementioned Project criteria, observations, slope stability analysis, and the recommendations in this report, the Project has an acceptable factor of safety of over 1.5 relative to deep-seated slope failures for the worst-case-scenerio of this Project. Seismic conditions were estimated utilizing worst case scenario values from the static analysis, a horizontal acceleration coefficient of 0.15, and applying the applicable values to slope stability charts. These stability charts were presented by the American Society of Civil Engineers (ASCE) in the "Journal of Geotechnical and Geoenvironmental Engineering," April 2002. See the slope stability information in Appendix C for input parameters and example of outputs. For this project, minimum factor of safeties for static and dynamic conditions were estimated to be 1.8 and 2.4, respectively. 5.4.1 Septic Drainfield Impacts The approximate locations of the planned septic drainfields are presented on the Site Plan in Appendix A of this report. The drainfields are not expected to adversely influence slope stability for the planned building structure or critical slopes. This determination is based on partial saturation inputs for the slope stability analysis, the soil types and minor elevation difference between the structures and drainfields, in addition to the location of the drainfileds with relation to the significant slopes on the Project. 5.4.2 Building and Footing Setbacks There are no minimum setbacks for this Project provided that the earthwork and other recommendations in this report are adhered to. 5.4.3 Erosion Control Erosion control measures may be required during construction due to disturbing the topography. This will mostly depend on the timeliness of construction, and amount of rainfall during construction. For this project, a complete storm water and erosion/ sediment control plan completed by Enviortech Engineering has addressed erosion control concerns. General erosion control information for both temporary and permanent erosion control is provided in appendix E. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 14 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason Countv, Washington October 4, 2007 5.4.4 Surface and Subsurface Drainage Positive drainage should be provided in the final design for all buildings. Surface and subsurface drains should be adequately maintained during the life of the structure. Drainage shall include sloping the ground surface, driveways, parking lots and sidewalks away from the Project structures. Foundation perimeter drains should be utilized for this Project if stem walls will be retaining more than 2 feet of soil. This will help mitigate the excess moisture away from the structure. If used, outlets for perimeter drains should be located downslope, and established at least 5 feet away from structures. It is also recommended to established foundation drains in a rock quarry or very gravelly, clean soils. If roof drains are utilized, water should be transported from the roof directly into a permeable medium that is downslope and at least 5 feet away from building foundations. This permeable medium should also not be located directly downslope from the building unless approved by the geotechnical engineer. If drainage problems occur during or after construction, additional water mitigation may be required. This may include a combination of swales, berms, drain pipes or outlet protection in order to divert water away from the structure and/or reduce erosion. 5.4.5 Vegetation Considerations Vegetation is recommended to remain in place as much as possible. However, vegetation may be removed as any means chosen from anywhere on this Project. For vegetation that is completely removed on slopes greater than 20%, it is recommended to level and lightly re-compact the native soils to the depth of soil disturbance. These additional requirements may be neglected if the stumps remain in place, and ground disturbance is minimal. 5.5 Pavement Analysis The pavement section design analysis was completed using AASHTO's Guide for Design of Pavement Structures. The AASHTO procedure utilizes the CBR value of the subgrade soil, traffic count reliability, serviceability or ability of the pavement to serve the type of traffic the facility will use, and the material properties of the asphalt concrete (AC) and base course (BC). The traffic data was assumed by Envirotech based on number of buildings and anticipated use. Data on reliability, serviceability, and standard deviation values were assumed based on AASHTO's procedures. The soil modulus was calculated Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 15 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4, 2007 based on correlation of soil properties with R-values. A nomograph presented in the AASHTO Guide, was used to calculate the structural number. The thickness of AC and BC were then calculated from the equation relating the structural number and the layer coefficients by assuming a standard AC thickness of 2 inches. Based on the result of the analysis, Envirotech recommends that the following pavement elements be utilized for parking areas: Flexible Pavement Risid Pavement • Asphalt concrete : 2.0 inches 6.0 inches • Base coarse : 8.0 inches The pavement design provided above assumes that the upper 8 inches of sub-base soil (pavement subgrade) is recompacted to its 95 percent compaction. Concrete in rigid pavements should have a 28-day compressive strength of 3000 psi. Appropriate concrete joints at 20 feet apart with transfer mechanisms should be included. Base coarse for parking lot construction should meet the requirements of Class B foundation material from the Washington State Department of Transportation Standard Specifications for Road, Bridge and Municipal Construction. 5.6 Earthquakes and Liquefaction Potential The immediate founding soils for this Project are primarily Type D, corresponding to the International Building Code (IBC) soil profiles. For this region, the seismic zone is 3, which yields an estimated maximum ground acceleration of 0.33g. The potential for liquefaction or lateral spreading is believed to be moderate for this Project. The sandy soils for this Project contributes to the liquefaction potential. However, the rapid stormwater infiltration that is widely distributed over the Project, and the lack of a permanent shallow water table are positive attributes regarding the potential for liquefaction. Biofiltration swales are proposed for the base of the site slopes in order to mitigate storm water. Other than preceding filter strips that will infiltrate much of the storm water, the swale is estimated to have only 4 inches of depth over a 1-foot width, and will transport water very quickly. Liquefaction potential is also decreased by removing at least 6 feet of soils on the top of the slope, and buildings situated at least 100 feet away from bio-filtration swales. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 16 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4, 2007 6.0 LIMITATIONS Due to the inherent natural variations of the soil stratification and the nature of the geotechnical subsurface exploration, there is always a possibility that soil conditions encountered during construction are different than those described in this report. Therefore, it is recommended that a qualified engineer observes and documents the construction, or Envirotech is promptly notified if project and subsurface conditions found on-site are not as presented in this report so that we can re-evaluate our recommendations. This report presents geotechnical design guidelines, and is intended only for the owner, or owners' representative, and project described herein. This report should not be used to dictate construction procedures or relieve the contractor of his responsibility. Any and all content of this geotechnical report is only valid on compliance with all recommendations provided in this report. The recommendations provided in this report are valid for the proposed development at the issuance date of this report. Changes to the site other than the expected development, changes to ordinances or regulatory codes, or broadening of accepted geotechnical standards may affect the conclusions and recommendations of this report. Please contact Michael Staten at 360-275 9374 if you have any questions comments, or require additional information. Sincerely, Envirotech Engineering Michael Staten, P.E. Geotechnical Engineer Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 Page 17 of 17 Parcel 12321-75-00020 Fax: 360-275-4789 Mason County, Washington October 4, 2007 APPENDIX A SITE PLAN A SCALE. I DCH-17o FEET ca)w K er NRsrse—v MWGARBAGE w °EEE"ACLE AREAS �J IXKTK.M' Gmvm SUtrocco Tn S \ `. uTARTr FVICEP YARD OR 1LDG A ar.tEE'> Rw FENCE _ O _s<oavFt TIC owLTRATOR I / YARD P6l1 CTM / SLAG■ PAfblf✓ACCESS n BEiiiEE `0• YR5RRESV EGRESS V. ; RECE"AC E AREAS / goDEGREE botav EGRESS S � / i >Lo SORDFIELD ✓ / CTYP> / / _ tr-Er CMMGE RE11PIACLE ASEAs / / VKL.2G /\-EXt%TM GV ACCESS. / UTRM EFS04M � � T OF EKMTeRG i PM1EE ROWAr of / PROJECT/ OWNER/ LOCATIUM BRET SCHWARZ GEOTECHNICAL ASSESSMENT NOTES- BRET SCHWARZ 00020 LEGEND L EROSION KWAT CLAM E IS PROVIDED D+ THELAN PARCEL NM MASON CIMMTIY. WASHINGTON sraaMvaTNxN AM EROSION CO�ITRII. PLAN COMPLETED BY ENVIRTJTECH EHG mt-t-K G. ENNGD'EER1 TEST PIT I�. CO�ouRs ARE NOT PRECISE, AND ONLY ENGINEERING em DEPICT GENERAL TOPOGRAPHIC CONDITIONS 3. THERE ARE NO NINDW BUFFERS 74 NE H-RD ROAD STORMWATER BE BETWEEN B DwGs Arm SLOPES FOR BrLF 7M5 9a74 TUN 98528 IS RUNOFF 4. ALL BUILDINGS ARE PLANNED TO BE 75 EXISTING CONTOUR WT x MWT IN SIZE SITE PLAN APPENDIX B SOH ,INFORMATION SCALE, 1 NCH 30 FEET 30 PROPOSED LANDSCAPE OR SIDEWALK PROPOSED ASPHALT PROPOSED BIO-INFILTRATION SWALE PAVED PARKING 2.5 FT DEEP, 311 SIDE ORIGINAL GRADE SLOPES, 1 FT BOTTOM 1-2% 50FT 25%t CLh �� SILTY SAND OR SAND <SP/SM) DENSITY 5FT -� 44� INCREASES WITH DEPTH C. 5FT PROPOSED GRADE C2�1) SECTION A-A PROJECT/ OWNER/ LOCATION, BRET SCHWARZ GEOTECHNICAL ASSESSMENT BRET SCHWARZ PARCEL NO. 12321 75 00020 MASON COUNTY, WASHINGTON NOTES: ENGINEER, ENVIROTECH ENGINEERING 1) LOCATION OF CROSS-SECTION IS SHOWN ON THE GEOLOGIC MAP B NE HURD ROAD BE NE WASHINGTON 98528 360-275-9374 S❑IL PR❑FILE TEST MT LOG TESL' PIT NUMBER TP-1 PROJECT: Schwarz Geotec:hnkaI Assessment DATE OF BORING: 05/05/07 PROJECT NO: 0726 LOGGED BY: MACS CLIENT: Brett Schwarz EXCAVATOR: Bret Schwartz LOCATION: Parcel 12321-75-00020 DRILL RIG: None Mason County,Washington ELEVATION: N/A INITIAL DEPTH OF WATER: N/A FINAL DEPTH OF WATER: N/A STANDAM p8&-mTm TEST SOIL STRATA, DEPTH FRS U3C3 DESCRIPTION LL Pt DEPTH � CURVE AND TEST DATA 10 50 SM Brown,motet SILTY SAND,ffw& n donee.Send is mostly fine and medium. Stlt is non- tic T•'+ 2 S - .0 :S �i 4 5 .f .... ........................ .............. SP Brown,motet.medun donee lo dense POORLY GRADED SAND wlh trace of ;' •:: stlta and gravels.Sand is mostly fine and 6 „�;••: medim.Slb are very low to none plasticity. 7 8 Brown,moist,dense POORLY GRADED ;;i a•;�: SAND with GRAVEL and trace of seta. ',•' : i. Sand is mostly med1m.Gravel content is d �-�� about 25%,and well graded. .t•: —10 E=avabon terminated at approximately 10 feet —x±— No Grotindweler F_noountmed ENVIROTECH ENGINEERING rnr.InA�rrn.00r+p+.ar>a ony ro rrs noAr�Q end aewdd roe to Geolodwks!ErgkwmdrV 1�br{xebd a wrp haicr��d�.nw a�w. TEST RT LOG TEST [SOT NUMBER TPm2 PROJECT: Schwarz Geotechnic al Assessment DATE OF BORING: 05�105/07 PROJECT NO: 0726 LOGGED BY: MCS CLIENT: Brett Schwarz EXCAVATOR: Bret Schwartz LOCATION: Parcel 12321-75-00020 DRILL RIG: None Mason County,Washington ELEVATION: NIA INITIAL DEPTH OF WATER: NIA FINAL DEPTH OF WATER: N/A STAFAMM PB&-MTM TEST SOIL STRATA, DEPTH SOIL U3C3 DESCRIPTION LL PI DEPTH N CURVE AND TEST DATA 10 30 50 0 SM Brown,moist SALTY SAND,medium donee.Sand is mostly rime and mediuum. Sit is rwn-piasfic 1 2 8 4 . . . .... . . ..................... .. ..... . .. . .. .. ..... . 5 SP Brown,moist.dense POORLY GRADED SAND with GRAVEL and trace of sdt L Sand b moody medkm-Gravel co ANd Is 8 about 2596,and wed graded. Brown,moist,melt n derm to dense :.; POORLY GRADED SAND with trace of T silts and graveis.Sand is moony line and medium. 8 E=avarion lemrinaled at appwdn d*8 feet 9 10 No Ground a;ler Enoou>tsrod ENVIROTECH ENGINEERING Tft o Lt @ft p GeoWmical Engineering TEST MT LOG TEST Pff NUMBER TP-4 PROJECT: Schwarz Geotec hnkal Assessment DATE OF BORING: 05/05/07 PROJECT NO: 0726 LOGGED BY: INKS CLIENT: Brett Schwarz EXCAVATOR: Bret Schwartz LOCATION: Parcel 12321-75-00020 DRILL RIG: None Mason County,Washington ELEVATION: N/A INITIAL DEPTH OF WATER: N/A FINAL DEPTH OF WATER: N/A srAAlAm pecrm7 orr TEST SOIL STRATA, DEPTH SAMPLERS USC3 DESCRIPTION LL PI DEPTH N CURVE AND TEST DATA 10 30 50 0 Sp-SM Brown,rrwist POORLY GRADED SAND with SILT and few gravels,medluM dense.Sand is mosty title and medtunn. 1 Sot is non-plastic ,;. 2 S - Sp Brown,moist,medium dense 10 dense POORLY GRADED SAND with few gravels and a trace of sit Sand Is mostly 4 ~:,; fie and medlurn. y•9i Y Brown,moist,dense POORLY GRADED SAND with GRAVEL and trace of silts. Sand Is mostly med u n.Gravel conlard is about 15%,and well graded. 7 E=avation brrrrin ded at app ukutely 7 feet 8 9 10 No Groundwater Encountered ENVIROTECH ENGINEERING Tft k*m ftn pwbkw o*r0 era Dorkp Mod&WW ace es GeOMc Mktel Engineering k�lwprabdas beft ft*09&OW�nrtir iNe TEST RT LOG TEST Pff NUMBER TP-1 PROJECT: Schwarz Geotechnicai Assessment DATE OF BORING: 06/05//07 PROJECT NO: 0726 LOGGED BY: MACS CLIENT: Brett Schwarz EXCAVATOR: Bret Schwartz LOCATION: Parcel 12321-75-00020 DRILL RIG: None Mason County,Washington ELEVATION: N/A INITIAL DEPTH OF WATER: NIA FINAL DEPTH OF WATER: N/A STRATA, sTANDMW PE ETMTM IEsr DEPTH SOIL STR T I�CS DESCRIPTION LL PI DEPTH N CURVE AND TEST DATA 10 30 50 . . .. ................... IsP-SM Brown,maid POORLY GRADED SAND wNh SILT and tract of gravels,medium dense.Sand Is mostly fide and medcnn. 1 Silt is low plastic. 2 3 4 . ............... . .. Sp Brawn.moist,dense POORLY GRADED SAND wllh GRAVEL and trace of silts. Sand Is mostly medium.Gravel content is 5 about 15%,and well graded. 8 T E=avaeon to aftrted at gVro*nately 7 fast 8 9 [10 No G ounctwater Erxounoerod ENVIROT ECH ENGINEERING Tilt a*v,,mft poftin any a srs comp and&*wW not be Geoledmk;al Engineering C"pi as b p hdcx.offt wi rs aft The Department of Ecology does NOT Warranty the Data and/or the Information on this Well Kepon. . $ ° g IF I lit GL &L • • t 1=I o R Ln oo o00 oar " g y $I ® N *+ $$ } a r r r r► a a4 IL LO r x1 w .:ti APPENDIX C SLOPE STABILITY Simplified Bishop Method Input major slope minor slope 36 1 Vertical Relief(ft) 116 100 Slope horizontal distance (ft) Soil Type Depth to top Unit weight friction angle, cohesion, of soil layer(ft) of soil(pcf) phi, (deg) c(p O M.Dense SM 0 140 28 200 Soil1 128 34 0 Soil 2 M.Dense SP 5 140 82 600 So113 V.Dense SPM 10 0 0 Soll 4 0 0 0 0 Soils 140 28 600 Minor Slope Surcharge(psf) 1800 Of slope must be beyond top of major slope to Surcharge distance from p 0 Surch Factor of Safety, FS Trial 1 2.5 assumed value Trial Radii ft) 60 Center of circle at top of slope Output Slope Inclination, beta (deg) 16.80 90- beta(deg) 73.20(73.20) (90)+beta+theta Horizontal Length of all slices(ft) 117.43 Horizontal length from center(ft) 57.43 horizontal distance from center of circle to left end of 1 st slice Radius of slip plane 1 (ft) 121.17 for a slip circle at toe of slope Factor of Safety, FS Trial 2 1.95 Factor of safety,FS Trial 3 1.89 Factor of Safety, FS Trial 4 1.88 aotnmtivv, tnoOto C7CV CD �., C� toonrNM �1 � dmO rO/ f- 1"wN rtpO mtODd + c O to N m -y u 0 0 0 0 0 0 0 0 0 0 `y ciciclNNNNNNN b M M M M M M M co M co C rC. O 0 0 0 0 0 0 0 0 0 0 M I`� M O m O m C O ACDtol� rr-- 00 N O CDCD § � mfD � �� Om 3ZA C CO "iC44 V N pCV rtoCV� Or �p P: mC sr Cl r r r r 8 h ti N N n to �- m to CO N co O O O—co rN 0 O co ae- mM O N �rco O O O O r O N /O r N ti Co- O rM Mr N -ttoMO g C (� md1� ONto 'Q tnto OOOO v- v- v- r r r r r � MdstrOr04 Wr- CO O mmmmCOCD I� r MNr rNMtn E m f- r.- r- - r-- r- C r- rrrrrr (A NN � QI t p LL N .r r CL :. O t4 C m-§ U O O m c CD � � OONOrt� `Q NmmtAq -W r- d/ OONtnM � �`' MN Cptliti A rCOM � � �iOtOpM W O coco � � P- �Q ttltpMO tV� � M f� CD et Q OrCptotof� MMt� CD �- deq d Nr 3 od c* mO .+ W Nrto Nl� tiCO rtiMONh- r O Crtof� CO � , co mN tt � c' tptlfmm OD 0 (A �i Z wwcomCD �- ^ � � M rOran .�t rtOtA CD c� O g 0 0 0 0 t- t� CDCD O pp rrt- e-� re- OO .-.co Q N L tL CL z H E mNrtoc lmco � CDCD C► Nd rOf� l� Or M rrh- 1%k -: (hrrONCO CD N N CV CO O Ly cal ob w co) Celt � ¢'' rM tnttf to W qtr OO NtnMOt- v Cl lam ft M trptj ^ � nmCD co tp > = O rNOW OCDCDmf� G! ZOOv--3 an � mcoOO to0i0itpOCD �} titp0 Opr r- ra- rrOO N CO '� to m to to d M to CO c� u � 0O0 m ttL U r r r o.4m cA 'A o E N O r N C7 (RI Co CD CD CD N C7 to m O N- CD M st01d> MMQOr � pui66w6 nto r ,r otriaor` c+iui co _ NM tPOmto rtM SNP- co m.r ONetr OMO OU� tOA � t � .. CONt� C � m m QtMotwAfd+ titim� O h Nr r m � z -1 o tip. tiN l� tl: r1l: t-fi M � I� NMOCOrtoO to CD O O O Cl O O O CD (p rrrrr �- - rrrr pOO rrrrrrrrrr r- re- rrOO Ci .a C Q LL cc � eNC9 � W CDtiCOM � EtICCD �d �DCDtiaO W � � usz EM-HUdV/OMEEMON3 WlN3yWODUVaO3O OW 1"NH031039 d0-NNii"/tom PEoq,ojW aaos cn da(dcmH)Lp JID) ONJO `..�.,.... s71�aql'� st (S) -ba - Paq�P minssaad ae s! 11 umId so �a � m `d �CP'PS aWd q� �JO a�Q 218 ongtA "� MO$ MMPW Id, ` .o 43S OW�T� 84�P as PWWU sa[�►3Q 1 3o asri�aa9�ImB so3 tool ap.u&Wm u8"Pinoas+mP qwS'cxkW3o m3 :W aq PPm-wmp w Mpm 2Wjo uogsgawsajd amaa ,tp;ss aau aqf 30 Dowaq you Am'*�/os a!`m'9o4 am ( so)raqmna��q -t qsT amssasd im m»d aqs aW=p a$Cj)3 P -qs ;o ! 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[au �P to Pala ylan POs_� "aasssa�d x�aes aJod rill }o apsglst8gm�,n aLagb s!31` mpn4o OW JO JWAMpq asp am g4sw Am aei�g you MOP Pm (kws al �) aeooid o�as asp sawn* s (8) ��°m"'a w!tans oikm'w9w1om apsm as mP mwi m *R n -pnla[a,(q a8!sap a!V=P!saoo aogo am sadots uO WuN a!m PS su(0961)um"Wd -M Pm doTslS Al Pm" °a WwOWN0 A P XF=P s<am PRAO OIUMVS nb -sand ra}sm asod at{i;o ao.mgws!P aip`ate 30&q ao .saes awd as$ao aauangR a[p 8unaoswd to asodmd asp sod sadoTs 30 rul!gy48 aq;ao==kid sagses awd amssard sale b awd alg 3o ap ca8esu asp at a8twga asasa tou ,To aoamgm asp 3o..sson8 pMuanpa„uo 07m a4 2lglsod u a4m gwp aa"Tps asp jo aomI1P alb Pas1aP 4io3 aq of P P1s mwj 1 4 ap-!seu'of pwo.fqm wdos jq m9mg 43PS 'V'S ' >('o a 5i3 ti0ti0 £D 20 1�D 5D DO 6'O Vo 0. 3o Y1! co s 1 i t ,Z£ Of 8 (P) tq) S'I 2 S'L L IID 0a S1 t 40 00 4L Z fft L SO �O E � 1-0�Vx L g , L ZOO z Sil y o ' iuq 0egr a s W 9 8 �� $ � �► 8 m(®, tot oats} OZ o4 APPENDIX D GEOLOGICAL MAP ScAu. t PCH •04 FEET Now-. -4 sw.ssr o / s / 1LBG A R-ev /O GATE TE 9 SOILS THFDJGH13UT SITE WERE IDENTIFIED AS USCS SH, SP-SN AND SP) USDA LOAMY FI]NUMEDIUM SAND AND FINE/1£DIIM SAM / A TOP 13F$LaP[ / TM W=0a Sl?E AT ON ff mo / W / PROJECT/ OWNER/ LOCATION• BRET SCHWARZ GE❑TECHNICAL ASSESSMENT BRET SCHWARZ LEGEND NOTES, PARCEL NO. IM1 75 00020 1. CONTOURS EXTAPOLATED FRDI PUBLIC MASON COUNTY, VASHINGTON LIDAR SOURCE, AND ONLY DEPICT GENERAL ENGINEER. *TPI TEST PIT TOPOGRAPHIC CONDITIONS. ENVIROTECH ENGINEERING 3. 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