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GeoTech Report - BLD Engineering / Geo-tech Reports - 9/16/2008
JtN 1 6 LUUd MASON COUNTY Geotechnical Report for Ball Single Family Residence 500 Cutlass Way Parcel 12330 33 00040 Mason County,Washington September 16, 2008 Project#0898 Prepared For: Tom Ball 500 Cutlass Way G�,e�`' wnsECLYDlEsT9T Belfair, Washington 98528 ti°� `'��,, 0 Prepared : /l6/00 Envirotech Engineering o R�43 5�o w � o GISTE4 �� 74 NE Hurd Road ONALti�Gti Belfair, Washington 98528 Phone: 360-275-9374 EXPIRES JAN 10,2009 Fax: 360-275-4789 TABLE OF CONTENTS 1.0 INTRODUCTION...........................................................................................................................1 1.1 PROJECT INFORMATION............................................................................................................... 1 1.2 PURPOSE OF INVESTIGATION........................................................................................................ 1 1.3 SCOPE OF WORK........................................................................................................................... 1 2.0 SURFACE CONDITIONS..............................................................................................................3 2.1 GENERAL OBSERVATIONS............................................................................................................3 2.2 TOPOGRAPHY...............................................................................................................................3 2.2.1 Upslope Geomorphology....................................................................................................... 3 2.2.2 Downslope Conditions.......................................................................................................... 3 2.3 SURFACE DRAINAGE.....................................................................................................................3 2.4 SLOPE AND EROSION OBSERVATIONS...........................................................................................4 3.0 SUBSURFACE INVESTIGATION.................................................................................................5 3.1 FIELD METHODS,SAMPLING AND FIELD TESTING........................................................................5 3.2 GENERAL GEOLOGIC CONDITIONS...............................................................................................5 3.3 SPECIFIC SUBSURFACE CONDITIONS.............................................................................................5 3.3.1 Groundwater......................................................................................................................... 6 3.4 SOILS TESTING.............................................................................................................................6 3.4.1 Visual Classification............................................................................................................. 6 4.0 ENGINEERING ANALYSIS,CONCLUSIONS AND RECOMMENDATIONS..........................7 4.1 BUILDING FOUNDATION RECOMMENDATIONS..............................................................................7 4.L I Bearing Capacity.................................................................................................................. 7 4.1.2 Settlement............................................................................................................................. 8 4.1.3 Concrete Slabs-on-Grade...................................................................................................... 8 4.2 LATERAL EARTH PRESSURES........................................................................................................8 4.3 EARTHWORK CONSTRUCTION RECOMMENDATIONS ....................................................................8 4.3.1 Excavation............................................................................................................................ 8 4.3.2 Placement and Compaction of Native Soils and Engineered Fill.......................................... 9 4.3.3 Retaining Wall Backfill........................................................................................................ 9 4.3.4 Wet Weather Considerations............................................................................................... 10 4.4 SLOPE STABILITY AND EROSION CONTROL................................................................................ 10 4.4.1 Septic Drainfield Impacts.................................................................................................... 12 4.4.2 Building and Footing Setbacks........................................................................................... 12 4.5 EROSION CONTROL.................................................................................................................... 12 4.5.1 Temporary Erosion Control................................................................................................ 13 4.5.2 Permanent Erosion Control................................................................................................ 13 4.6 SURFACE AND SUBSURFACE DRAINAGE...................................................................................... 13 4.7 VEGETATION BUFFER AND CONSIDERATIONS............................................................................. 14 4.8 ON-SITE AND OFF-SITE IMPACTS ............................................................................................... 14 4.9 SEISMIC CONSIDERATIONS AND LIQUEFACTION......................................................................... 14 4.9.1 Liquefaction........................................................................................................................ 14 5.0 CLOSURE..................................................................................................................................... 15 Appendix A-Site Plan Appendix B-Geologic Map Appendix C-Soil Information(Soil Profile; Soil Logs, Well Reports) Appendix D-Slope Stability Input&Output Appendix E—Erosion Control 1.0 INTRODUCTION Envirotech Engineering (Envirotech) has completed a geotechnical investigation for a property located at 500 Cutlass Way, identified as parcel number 12330 33 00040, 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 soil descriptions in the Subsurface Investigation Section; and, recommendations for foundation, settlement, earthwork construction, lateral earth pressures, slope stability, erosion control, drainage and vegetation considerations in the Engineering Analysis and Recommendations Section. An initial geotechnical evaluation of the Project was conducted by Envirotech with the property owner, Tom Ball, on September 9, 2008. It was determined that slopes in excess of 40% with a vertical relief of at least 10 feet were present within 300 feet of the planned development. Consequently, the proposed development will require a geotechnical report pursuant to Landslide Hazard Areas of Mason County Resource Ordinance 17.01.100. During the site visit 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 property owner with general assumptions by Envirotech that are typical of this type of development. The Project is accessed from Cutlass Way, an improved road in Belfair, Washington. See the vicinity map on the following page of this report for a general depiction of the property location. The property is currently developed with an on-site septic system, gravel surfaced driveway, and mobile structures. The planned development will initially consist of a 1-or 2-story garage/shed structure. A 1- or 2- story single family residence is planned after completion of the garage. Foundation construction is expected to consist of continuous strip footings and concrete slabs-on-grade. The residence may incorporate stem walls. Approximate building footprint with relation to site features are illustrated in the Site Map in Appendix A. 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 development of the property. The investigation included characterizing the general Project surface and subsurface conditions, and evaluating the suitability of the soils to support the planned site activities. 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 and/ or owner's representative; • Conduct a site visit to document the site conditions that may influence the construction and performance of the proposed improvements; • Define the general subsurface conditions of the site by observing subsoils extending to a Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 1 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County, Washington September 15,2008 round surface review geological maps for the depth of over 10 feet below the naturalg g g p general area, research published references concerning slope stability, and review water well reports from existing wells near the Project; • Collect bulk samples at various depths and locations; • Perform soils testing to determine selected index properties of the soils that include 4 visual classifications; • Complete an engineering analysis supported by the planned site alterations, and the surface and subsurface conditions that were identified by the field investigation, soil testing, and applicable project research; and, • Establish conclusions based on findings, and make recommendations for foundations, drainage, slope stability, erosion control, earthwork construction requirements, and other considerations. 23 24 - x d0ff } � 26 25 ; o't lox W T23NR�W �! W Sd ,�� �`�f (/ � / NE SEITZ DR ° ' a� T23NRZW E .e 1 ,f rrojea NE UEYA to 31 35 3 1 m Q HOOD CANAL r„ �O < �r m=- �ouReut- W' _� � ( J 3580R Vicinity Map from Mason County Website Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 2 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County, Washington September 15,2008 2.0 SURFACE CONDITIONS Information pertaining to the existing surface conditions for the Project was gathered on September 9, 2008 by Michael Staten, geotechnical engineer with Envirotech. During the site visit,the type of geotechnical investigation was assessed, site features were documented that may influence construction and slope stability, soil samples were collected from selected locations, and near-surface soils were visually classified. This Surface Conditions Section provides information on general observations, vegetation, topography, drainage and slope/ erosion conditions for the Project and surrounding areas that may impact the Project. 2.1 General Observations The Project is partially developed land as previously mentioned. Cutlass Way terminates at the south end of the Project. Beyond the property lines, rural residential development exists. It has been reported that rail road tracks formerly crossed this property within the general confines of the existing driveway. The track pad is apparent beyond the property line to the north. Vegetation on and near the Project consists primarily of firs,alders,blackberry,and other trees and shrubbery common to this area of the Pacific Northwest. An aerial photo of the project and immediate vicinity is provided on the following page. 2.2 Topography The Project is situated within and near moderate to steep sloping terrain. The planned building envelope locations appear to be primarily on slightly sloping terrain of less than 2%. The topographic information provided in this section was extrapolated from a public lidar source, and incorporated observations and field measurements. Where necessary, slope verification included measuring slope lengths and inclinations with a cloth tape and inclinometer. See the Site Map in Appendix A and the Geological Map in Appendix B in this report for an illustration of general topography with respect to the planned development. 2.2.1 Upslope Geomorphology The ascending cut slope located immediately to the east of the planned development is approximately 128% with a maximum of 13 feet vertical relief. Beyond the cut slope, err y y r ascending grades are variable, and average about 26%. There are no apparent water bodies or wetlands located upslope from the planned development. 2.2.2 Downslope Conditions Natural descending grades of approximately 27%to 31%exist to the west of the planned development except in the location of earth fill located within the northwest portion of the property. The descending fill slope has a maximum grade of nearly 70% with a vertical relief of 14 feet. 2.3 Surface Drainage Stormwater runoff originatingu slo a from the anticipated development is expected to be P P P P minimal due to the topography. Sheet flow towards the west is expected before it reaches the proposed residence. Excessive scour, erosion or other indications of past drainage problems were Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 3 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County, Washington September 15, 2008 not observed at or near the planned development. 2.4 Slope and Erosion Observations The existing steep slopes near the Project signal a potential landslide or erosion hazard area. Some indicators that may suggest past slope movements 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. Significant mass wasting on the property or within the general vicinity of the Project were not observed or discovered during research. Indications of past landslides, current unstable slopes, deep-seated slope problems,or surficial slope failures were not observed during the site visit. <s; a `7r 4 Aerial Photo from Mason County Website Envirotech Engineering Geotechnical Investigation Ph 360-275-9374 page 4 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County,Washington September 15,2008 3.0 SUBSURFACE INVESTIGATION Information on subsurface conditions pertaining to the Project was gathered on September 9, 2008 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. Appendix C of this report includes pertinent information on subsurface conditions for the Project, such as subsoil cross-sections, test pit log(s) representative of the bearing soils of the planned building, and water well report(s). Applicable test pit locations are depicted on the Site Plan and Geologic Map provided in the appendix of this report. 3.1 Field Methods, Sampling and Field Testing Information on subsurface conditions for the Project was accomplished by examining soils within test pits and cut slopes extending to depths of at least 10 feet below the natural ground surface. Information on subsurface conditions also included reviewing geological maps for the vicinity of the Project,and water well reports originating from nearby properties. One bulk sample was collected at the Project site at approximately 6 inches below the existing ground surface near the anticipated building location. The soil sample collected was secured and transported for possible laboratory testing. Envirotech measured the relative density of the near-surface in-situ soils by gauging the resistance of hand tools.Within testing locations from natural grade, field testing results generally indicated medium dense soils in the upper 36 inches,and dense to very dense soils from 36 inches to the depth of terminous. Dense to very dense soils were measured within the anticipated building footprints at a depth of less than 6 inches. 3.2 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. Eric Schuster, 2002 indicates Quaternary sediments, Qg. Quaternary sediments are generally unconsolidated deposits, and dominantly deposited from glacial drift, including 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. 3.3 Specific Subsurface Conditions The following subsurface conditions are estimated descriptions of the Project subgrade utilizing information from the depth of penetration at all testing, sampling, observed and investigated locations. Soils for this project were described utilizing the Unified Soil Classification System (USCS). Using the USCS in conjunction with estimated relative densities and other anticipated engineering properties of the soil, susceptibility for potential landslides, erosion and seismic hazards may be assessed. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 5 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County,Washington September 15,2008 The Project is composed of native soils with borrowed fill as shown on the Geologic Map. For engineering purposes, soils consist of distinguishable layers, as presented below. The fill soils are comprised of nearly the same gradation as the native soils, and appear to be slightly compacted. These soils most likely originated from the earth cut on the property. Soils within the upper 10 feet of natural ground were observed to be moist, brown silty sand with gravel (SM). The relative densities of this soil are provided in Section 3.1 of this report. Gravels are primarily well-graded, and subrounded. Sand content was primarily well-graded, and the fines content exhibited none to low plasticity. Soils below the upper 3 to 7 feet layer to the depth of terminous consisted of brownish grey, very dense `hardpan.' According to the well reports and knowledge of the general area, soils below the observed 10 feet in depth are dense to very dense glacial till. This till usually extends to depths between 30 and 100 feet below the ground surface. 3.3.1 Groundwater From the water well reports and knowledge of the general area, permanent groundwater is over 100 feet directly below the property at the building pad location. Perched groundwater at shallow depths was not observed on-site, nor indicated on the well reports. 3.4 Soils Testing The soil samples obtained at the Project site during the field investigation were preserved and transported for possible laboratory testing. Visual classification of soils was performed in the field. The following soil tests were performed in accordance with the American Standards for Testing and Materials(ASTM): 4 Visual Classifications (ASTM D2488) 3.4.1 Visual Classification The results from the visual classification are presented above in the Subsurface Conditions Section at depths of up to 10 feet below the natural ground surface. Specifically, soils within the upper 10 feet consisted of approximately 20%gravel, 65% sand-sized soils, and 15%silt. 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 overall engineering properties of the soil. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 6 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County, Washington September 15,2008 4.0 ENGINEERING ANALYSIS,CONCLUSIONS 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 including drainage and topography as recapitulated in the Surface Conditions Section; and, soil conditions that were identified from the geotechnical investigation that is summarized in the Subsurface Investigation Section. Engineering analysis and recommendations for the Project that is provided herein, includes pertinent information for building foundations, earthwork construction, slope stability/erosion control, drainage,vegetation and seismic considerations. 4.1 Building Foundation Recommendations Recommendations provided in this section account for the site development of a typical one- or two-story, single family residential structure. Below the upper 12 inches of Project soils at the building pad location, there is apparently one distinguishable layer of soil that will influence the bearing capacity and settlement of the structures. 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. 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 should be used only to the extents provided in this report. Building foundations should not be located on the fill soils. Currently, Project information includes building envelopes located outside of fill areas. If buildings are to be located on fill, field density testing of these soils should be completed to verify competent bearing strata. 4.1.1 Bearing Capacity For the existing site conditions, bearing values should increase with depth. Existing in- situ soils for this Project indicates that the structure 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 1500 pounds per square feet(psf) maximum structural bearing pressure. For a bearing capacity requirement of no more than 1500 psf, a minimum footing width of 12 inches shall be placed at a minimum of 12 inches below the existing ground surface. An allowable bearing capacity of 2000 psf is allowed if footings are increased to at least a minimum width of 15 inches. Foundation recommendations are made available based on adherence to the remaining recommendations that are provided in this report. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 7 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County, Washington September 15,2008 4.1.2 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, anticipated development, 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. 4.1.3 Concrete Slabs-on-Grade Interior slabs, if utilized, should be supported on a minimum of 6 inches of compacted coarse, granular material that is placed over undisturbed native subgrade or engineered fill. Native soils found at the Project site are not suitable for use as the material directly beneath concrete slabs.The top 2 to 4 inches of native soil should be removed prior to the placement and compaction of the aforementioned 6-inch coarse, granular material. Although not required for the structural integrity of the concrete slab-on-grade, a vapor barrier is usually used for damp-proofing. If vapor barriers are used, it is suggested 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. 4.2 Lateral Earth Pressures 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. Significant retaining structures are not anticipated for this Project. If retaining walls are later planned for this Project, prescriptive requirements from the County should be adhered to. For retaining structures with a height exceeding County prescriptive requirements, additional design parameters must be accounted for in the retaining wall analysis, and recommendations should only be provided by a qualified engineer after the type of backfill is acquired, inclination of backfill slope is estimated, and the final wall height is determined. 4.3 Earthwork Construction Recommendations Founding material for building foundations shall consist of undisturbed native soils. Compacted engineered fill, or selective re-compacted native soils may be used to the extents provided in this Earthwork Construction Recommendations Section. The following recommendations include excavations, subgrade preparation,type of fill, and placement of fill for building foundations. 4.3.1 Excavation Excavation is recommended to remove any excessive organic content or other deleterious material, if present, beneath foundations and to achieve appropriate foundation depth. Additional sub-excavation will be required for this Project if the soils below the required foundation depth are loose, saturated, or otherwise incompetent due to inappropriate land disturbing, or excessive water trapped within foundation excavations prior to foundation Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 8 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County, Washington September 15,2008 construction. All soils below the bottom of the excavation shall be competent, and relatively undisturbed or properly compacted fill. If these soils are disturbed or deemed incompetent, re-compaction of these soils below the anticipated footing depth is necessary. Excavations shall be completely dewatered, compacted, and suitable before placement of additional native soil, engineered fill or structural concrete. It is suggested that foundation excavations are inspected by a geotechnical engineer or qualified professional in order to assess the bearing material prior to the placement of structural footings. 4.3.2 Placement and Compaction of Native Soils and Engineered Fill For engineered fill or disturbed native soils that will be utilized as fill material directly beneath foundations, observation and/ or geotechnical testing is recommended prior to foundation construction. The following placement and compaction requirements are necessary. For disturbed native soils or engineered fill beneath foundations, limits of compacted or re-compacted fill shall extend laterally from the bottom edge of the foundation at a rate of one foot for each foot of compacted or re-compacted fill beneath the foundation. See the illustration below. FOOTING COMPACTED NATIVE SOILS OR ENGINEERED t FILL I II UNDISTURBED SUBGRADEI 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 60%to 100%gravel-sized material (particles between 3/16-inch and 3 inches), and less than 10%fines(particles passing#200 standard sieve)by weight. Compaction 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) and within 3% of optimum moisture content. Each lift surface should be adequately maintained during construction in order to achieve acceptable compaction and inter-lift bonding. 4.3.3 Retaining Wall Backfill As previously mentioned, significant retaining structures are not anticipated for this Project. However, if used, native soils may be used as retaining wall backfill for this Project. Backfill may also consist of engineered fill or borrow materials approved by a geotechnical engineer. Placement, compaction and extents of retaining wall backfill should also be specified by a geotechnical engineer or qualified professional. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 9 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County,Washington September 15,2008 4.3.4 Wet Weather Considerations Due to the types of subsurface soils, additional provisions may be required during prolonged wet weather. Every precaution should be made in order to prevent free moisture from saturating the soils within excavations. If the bottom of excavations used for footing placement changes from a moist and dense/hard characteristic as presented in this report to muck or soft, saturated conditions, then these soils become unsuitable for foundation bearing material. If this situation occurs, a geotechnical engineer should be notified, and these soils should be completely removed and replaced with compacted engineered fill or suitable native material as presented in this section. 4.4 Slope Stability and Erosion Control Landslides are natural geologic processes, and structures near slopes possess an inherent risk of adverse settlement, sliding or structural damage due to these processes. Geotechnical engineering cannot eliminate these risks for any site with sloping grades because gravity is constantly inducing strain on the sloping soil mass. Excessive wet weather and/ or earthquakes will exacerbate these strains. Geotechnical engineering considers excessive wet weather and `design' earthquakes in order to provide an acceptable factor of safety for developing on or near sloping terrain. These factors of safeties are based on engineering standards such as defining engineering properties of the soil,topography,water conditions, seismic acceleration and surcharges. 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. According to the Resource Map from the Washington State Department of Natural Resources (DNR), the Project is not within terrain labeled `highly unstable' or `highly erodible' relating to soils. In addition, DNR did not indicated previous landslide activity near the Project. DNR labeled portions of this project as medium and high slope instability with relation to slopes. This delineation is primarily dependent upon slopes and convergence. Secondly, lithology and precipitation are modeled within this delineation. In summary, this designation is based on mapping without field observations or knowledge of the specific site geology or soils. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 10 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County,Washington September 15,2008 l f • r M1 Fes• iO4�<6 170N4 F Lacaa lake F-1 • 5 ri 26 t F L ._1701L Project 4j�'• +� w rw rfi / r N Fw rw LM1 / F. N w Fw F'fi 1• ~ .!N FN N w rw Fw �� f••f �A !L FW W Fw FIN. U1 A • _ FW W Fw IY ' 1 st _... srat•i soave S� ! Map from Washington State Department of Natural Resources Website The Simplified Bishop Method, utilizing `STABLE' software, was used to analyze the static stability of the site slopes. Various radii's and center points of the circle were automatically selected, and produced factor of safeties in a graphical and tabular format. Worst case scenario values were used in the slope stability analysis in regards to topography, surcharges, water content, and cohesion of the site soils. STABLE software has been repeatedly checked with manual calculations, and consistently proved to be a very conservative program. The following soil properties were used in the analysis, and are based on observed conditions, known geology, and/or published parameters: Top 4 feet of weathered soils • Soil unit weight: 136 pcf • Angle of internal friction: 32 degrees • Cohesion: 0 psf Soils below 4 feet • Soil unit weight: 140 pcf • Angle of internal friction: 40 degrees • Cohesion: 100 psf Seismic conditions were estimated utilizing worst case scenario values from the static analysis, a quasi-static analysis coefficient of at least 0.15, and applying the applicable values to STABLE software. Anticipated building loads, building pad cuts, or impacts from septic drainfields are not expected to have any detrimental influence on the global stability of the slopes, provided that the setback Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 11 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County,Washington September 15,2008 requirements, drainage and all other 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, static slope failures at the building locations. Furthermore, an acceptable factor of safety of over 1.1 for seismic conditions was also concluded for this Project. See the slope stability information in Appendix D for input parameters and example of outputs. Although minimum factors of safety were calculated to be below requirements on the slope face and up to 25 feet from the top of the slope, minimum factor of safeties for static and dynamic conditions at building locations were estimated to be 3.4 and 1.9,respectively. 4.4.1 Septic Drainfield Impacts The approximate location of the existing septic drainfield is presented on the Site Plan in Appendix A of this report. Based on the septic drainfield location with relation to the existing and proposed topography, the drainfields are not expected to adversely influence the structures near the critical slopes. This is also based on compliance with the recommendations in this report. 4.4.2 Building and Footing Setbacks Provided that assumptions relating to construction occur and recommendations are followed as presented in this report,the factor of safety for slope stability is sufficient for the following setbacks. • 50 feet footing setback between building foundations and the top of the descending fill slope. • 10 feet footing setback between building foundations and the top of the descending cut slope. • 6 feet footing setback between buildings and the toe of the ascending cut slope. The building is considered the outside face of exterior walls, not roof overhangs. See the Geologic Map in Appendix B for an illustration of these setbacks. 4.5 Erosion Control Based on the USCS description of the Project soils, the surface soils are considered moderately erodible. Temporary and/ or permanent erosion control measures may be required for site development. Extents of temporary erosion control will mostly depend on the timeliness of construction,moisture content of the soil, and amount of rainfall during construction. Soil erosion typical to the existing site conditions and planned disturbance of the Project include wind-borne silts during dry weather, and sediment transport during prolonged wet weather. Sediment transport could be from stormwater runoff or tracking off-site with construction equipment. Erosion control measures may need to be employed if excessive erosion occurs or required by the County or other prevailing agencies. 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. Additional erosion control information and specifications Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 12 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County, Washington September 15,2008 may be found in the appropriate "Stormwater Management Manual for Western Washington," prepared by the Washington State Department of Ecology Water Quality Program. 4.5.1 Temporary Erosion Control Erosion control during construction should include minimizing the removal of vegetation to the least extent possible. If necessary, erosion control measures during construction may include stockpiling cleared vegetation, silt fencing, intercepting swales,berms, straw bales, plastic cover or other standard controls. Silt fencing is presented in this report as the first choice for temporary erosion control. Any erosion control should be located down-slope and beyond the limits of construction and clearing of vegetation where surface water is expected to flow. If the loss of sediments appears to be greater than expected, or erosion control measures are not functioning as needed, additional measures must be implemented immediately. See Appendix E for sketches and general notes regarding selected erosion control measures. The Site Map in Appendix A depicts the recommended locations for erosion control facilities to be installed, if necessary. 4.5.2 Permanent Erosion Control Permanent erosion control may also be necessary if substantial vegetation has not been established within disturbed areas upon completion of the Project. Temporary erosion control should remain in place until permanent erosion control has been established. Permanent erosion control may include promoting the growth of vegetation within the exposed areas by mulching, seeding or an equivalent measure. Selected recommendations for permanent erosion control are provided in Appendix E. Additional erosion control measures that should be performed include routine maintenance and replacement, when necessary, of permanent erosion control, vegetation, drainage structures and/or features. The following Surface and Subsurface Drainage Section may have additional recommendations with relation to permanent erosion for surface drainage features. 4.6 Surface and Subsurface Drainage Positive drainage should be provided in the final design for all planned residential buildings. Drainage shall include sloping the ground surface, driveways and sidewalks away from the Project structures. All constructed surface and subsurface drains should be adequately maintained during the life of the structure. If drainage problems occur during or after construction, additional engineered water mitigation will be required. This may include a combination of swales, berms, drain pipes, infiltration facilities, or outlet protection in order to divert water away from the structures to an appropriate protected discharge area. From a geotechnical perspective, footing drains are optional for the single family residence and detached garage. If footings are established at depths greater than 2 feet below final grade, then perimeter footing drains are recommended. Roof drains should at least have a protected outfall at the downspout. If drainage pipes are installed for roof runoff control, then stormwater should be directed to a permanent infiltration or outlet protection pad located outside the building setback as presented in this report. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 13 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County,Washington September 15,2008 4.7 Vegetation Buffer and Considerations Vegetation is an excellent measure to minimize surficial slope movements and erosion on slope faces and exposed surfaces. By removing trees, the root strength is decreased over time, thereby lowering the `apparent' cohesion of the soil. Transpiration is decreased, which results in additional groundwater, increased pore water pressure and less cohesion/ friction of the soil particles. Stormwater runoff also increases, and, fewer plants will create less absorption of the force from raindrops,thereby creating the potential for erosion hazards. Vegetation shall not be removed on the face of any slope exceeding 40%. However, any tree deemed hazardous to life or property shall be removed. If tree removal is necessary, then stumps and roots shall remain in place, and the underbrush and soil shall remain undisturbed as much as possible. Any disturbed soil shall be graded and re-compacted in order to restore the terrain similar to preexisting conditions and drainage patterns. See the Geologic Map in Appendix B of this report for a depiction of the vegetation buffer. 4.8 On-Site and Off-Site Impacts From a geotechnical position, it is Envirotech's opinion that the subject property and adjacent properties to the proposed development should not be significantly impacted if all recommendations in this report are followed. This is based on the expected site development, existing topography, land cover, and the recommendations presented in this report. 4.9 Seismic Considerations and Liquefaction Soils immediately below the expected foundation depth for this Project are generally Type C, corresponding to the International Building Code (IBC) soil profiles. According to the IBC, the regional seismic zone is 3 for this Project. The estimated peak ground acceleration ranges from 0.50g to 0.60g. This estimation is based on the United States Geological Survey(USGS)National Seismic Hazard Project in which there is an estimated 2% probability of exceedance within the next 50 years. There are no known faults beneath this Project. The nearest Class `A' or Class `B' fault to this property is the Tacoma Fault Zone, in which is approximately 5 miles to the south of this Project. This information is based on the USGS Quaternary Fault and Fold Database for the United States. 4.9.1 Liquefaction The potential for liquefaction is believed to be low for this Project. This is based, in part, on the slope stability analysis utilizing seismic considerations in addition to subsurface conditions such as soil characteristics and the lack of a permanent shallow water table. Subgrade characteristics that particularly contribute to problems caused from liquefaction include submerged, confined, poorly-graded granular soils. Although gravel- and silt- sized soil particles could be problematic, fine and medium grained sands are typically subjected to these types of seismic hazards. No significant saturated sand stratifications are anticipated to be within the upper 50 feet of the subsoil for this Project. Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 14 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County,Washington September 15,2008 5.0 CLOSURE Based on the project information and site conditions as presented in this report, it is Envirotech's opinion that additional geotechnical studies are not required to further evaluate this Project. 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 location of 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 in conjunction with the compliance of all recommendations provided in this report. Semantics throughout this report such as `shall,' `should' and `recommended' imply that the correlating design and/or specifications must be adhered to in order to protect life and property. Semantics such as `suggested' or `optional' refer that the associated design or specification may or may not be performed. 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. 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. Please contact Michael Staten at 360-275-9374 if you have any questions, comments, or require additional information. Sincerely, Envirotech E gmeerin Michael Staten, P.E. Geotechnical Engineer Envirotech Engineering Geotechnical Investigation Ph. 360-275-9374 page 15 Parcel 12330 33 00040 Fax: 360-275-4789 Mason County, Washington September 15,2008 APPENDIX A SITE PLAN 235FT± N SCALE- 1 INCH = 6 FEET P ❑P❑SED a NGLE FAMILY ESIDENCE TOP F LOPE TP TEMPORARY ER❑SI❑ ti ❑NTR❑L (TYP), IF oa NECESSARY ti ; v v ti a q 2� T P 2 k Q PROPOSED q GARAGE 2� 3 EXI TING CUT SL PE (128%) EXISTIN GRAVEL DRIVEWAY PROPERTY LINE 190FT± Q 3 O � ��� PROJECT/ OWNER/ LOCATION, J SINGLE FAMILY RESIDENCE u GEOTECHNICAL REPORT TOM BALL PARCEL 12330 33 00040 NOTES LEGEND MASON COUNTY, WASHINGTON 1. EROSION CONTROL MAY BE REQUIRED FOR THIS SITE. GENERAL LOCATIONS, AND ALTERNATIVES TO SILT FENC S ENGINEER, MAY BE UTILIZED AS EXPLAINED IN THE GEOTECHNICAL EROSION CONTROL ENVIROTECH ENGINEERING REPORT. 74 NE HURD ROAD 2, CONTOURS WERE NOT PREPARED BY A LICENSED LAND SLOPE DIRECTION BELFAIR, WASHINGTON 99529 SURVEYOR. CONTOURS WERE EXTRAPOLATED FROM A PUBLIC 8o EXISTING CONTOUR 360-275-9374 LIDAR SOURCE, AND INCORPORATED FIELD MEASUREMENTS AS EXPLAINED IN THE GEOTECHNICAL REPORT. TP1 TEST PIT SITE PLAN APPENDIX B GEOLOGIC MAP SCALE- 1 INCH = 80 FEET q ' 235FTt /,50 FT BUILDING SETBACK / FROM TOP OF S PE 4 /, P as 4 GLE FAMILY IDENCE A \ / I TOP F SLOPE T / XC E G 40% TOE OF SLOPE / 10 FT BUILD/GiUSETBACK EXCEEDING 40% FROM TOP ❑ PE ► SO GLACIAL TILL MEDIUM DENSE c 6 FT BUILDI G TBACK SI T SAND WITH G AVEL (SM) FROM TOE ❑ T SLOPE/ ❑ LYING VERY D NSE SM �2 Td ;e ROPOSED / 4rq GARAGE CU SLOPE REPRESENT TOP, /T AND SIDES OF CR TICAL S PES VEGETATJI S ALL NOT BE XI T NG CUT REMOVEDT EEN THE TOP AND SL P (128%) TOE I T AL SLOPES 040%) WITH EX EPT ONS (SEE REPORT) XISTIN GR VEL DRIVEWAY P OPERTY LINE 19OFTt 3 O y z ep0 ! H u U PROJECT/ OWNER/ LOCATION- SINGLE FAMILY RESIDENCE GE❑TECHNICAL REPORT TOM BALL PARCEL 12330 33 00040 LEGEND MASON COUNTY, WASHINGTON ENGINEER, BUFFER/SET BACK ENVIROTECH ENGINEERING NOTES, 74 NE HURD ROAD 1. CONTOURS WERE NOT PREPARED BY A LICENSED LAND SLOPE DIRECTION BELFAIR, WASHINGTON 98528 SURVEYOR. CONTOURS WERE EXTRAPOLATED FROM A PUBLIC 360-275-9374 LIDAR SOURCE, AND INCORPORATED FIELD MEASUREMENTS AS eon EXISTING CONTOUR J[ EXPLAINED IN THE GEOTECHNICAL REPORT. 7p1e TEST PIT GEOLOGIC MAP APPENDIX C SOIL INFORMATION VERTICAL AND HORIZONTAL SCALE- I INCH = 40 FEET 0 10 20 40 EXISTING CUT PROPOSED HOUSE EXISTING GRADE EXISTING FILL 2%± r r r X� MEDIUM DENSE DENSE SILTY SAND WITH GRAVEL (SM) r 2��+ DENSE GLACIAL TILL (SM)' r ------- r r r r r r r r r r r r r SECTION A-A PROJECT/ OWNER/ LOCATION- SINGLE FAMILY RESIDENCE GE❑TECHNICAL REPORT TOM BALL PARCEL 12330 33 00040 MASON COUNTY, WASHINGTON NOTES ENGINEER 1) MINOR GRADE CHANGES WILL BE COMPLETED IN ORDER ENVIROTECH ENGINEERING TO ACHIEVE POSITIVE DRAINAGE. 74 NE HURD ROAD 2) THE SOIL PROFILE IS ACCURATE FOR THE DEPTH OF BELFAIR, WASHINGTON 98528 THE OBSERVED TEST PITS AT THE SPECIFIED LOCATIONS. 360-275-9374 LOWER DEPTHS ARE BASED ON SITE GEOLOGY, WELL LOG(S), AND/OR EXPERIENCE IN THE GENERAL AREA. SOIL PROFILE TEST PIT LOG TEST PIT NUMBER TP-1 PROJECT: SFR Geotechnical Report DATE OF LOG: 09/9/2008 PROJECT NO: 0898 LOGGED BY: MCS CLIENT: Tom Ball EXCAVATOR: N/A LOCATION: Parcel 12330 3300040 DRILL RIG: None Mason County, Washington ELEVATION: N/A INITIAL DEPTH OF WATER: N/A FINAL DEPTH OF WATER: N/A SOIL STRATA, STANDARD PENETRATION TEST DEPTH SAMPLERS USCS DESCRIPTION LL PI CURVE AND TEST DATA DEPTH N 10 30 50 0 ...... . . .... .I .......... . . .. ... SM Brown, moist, medium dense SILTY SAND with GRAVEL. Gravel is well-graded and subrounded. Sand is 1 primarily well-graded. None to low plasticity. 2 - 3 Dense 4 5 6 7 Very dense'hardpan' 8 9 110 '. Excavation terminated at approximately 10 feet No Groundwater Encountered ENVIROTECH ENGINEERING This information pertains oniy to this.boring and should not be Geotechnical Engineering interpreted as being indicitive of the entire site. TEST PIT LOG TEST PIT NUMBER TP-2 PROJECT: SFR Geotechnical Report DATE OF LOG: 09/9/2008 PROJECT NO: 0898 LOGGED BY: MCS CLIENT: Tom Ball EXCAVATOR: N/A LOCATION: Parcel 12330 33 00040 DRILL RIG: None Mason County, Washington ELEVATION: N/A INITIAL DEPTH OF WATER: N/A FINAL DEPTH OF WATER: N/A STANDARD PENETRATION TEST SOIL STRATA, DEPTH SAMPLERS USCS DESCRIPTION LL PI CURVE AND TEST DATA DEPTH N 10 30 50 0 1 .......... ............................... ....... SM Brown, moist, medium dense SILTY SAND with GRAVEL. Gravel is well-graded and subrounded. Sand is 1 primarily well-graded. None to low plasticity. 2 3 Dense 4 Very dense'hardpan' 5 Moderate Cementation 6 7 8 A- -9 110 Excavation terminated at approximately 10 feet No Groundwater Encountered ENVIROTECH ENGINEERING This information pertains only to this boring and should not be Geotechnical Engineering interpreted as being indicative of the entire site. Firs Fite Department and Ecology Copy with WATER WELL REPORT Department of Ecology Application No. . .__.-.----- - =Steond Copy- Owner's Copy- Copy-Driller's Copy #TATZ OF WASHING bN Permit No. .-.. y (I) OWNER• Name. Thomas Spencer.._...............-'.-.._.-....... Addrese_-.. . .. ........................--........... .... _ _ QL - - ......................... .- ;i -... .... i Sec.. T,rU...N., R...LV w.m. Be,ring and distance from section or subdivlt,ion corner I (3) PROPOSED USE: Domestic X Industrial ❑ Murdmpal Fj (10) WELL LOG: _ Q1 Irrigation ❑ Test Well ❑ Other ❑ tormatton:Describe by color,character slice of material and structure,and shoo thickness of aquifers and the kind and nature of the material In each (4) TYPE OF WORK owner's number of well stratum penetrated;with at Lase owe entry for each chewge of fornsation, y 1 if a than one) .......... l[AT77t[AL rROM TO 7 New well Method:Dug, 0 Bored ❑ +a Deepened ❑ Cable? Q Drivm D - TILL -- O tary Reconditioned Q Rau"❑. -Tatted ❑ DT TILL CONGLOMERATEBR 61 C (5) DIMEN �NS: Diameter of well .._..6..... Inches. ... ... ,0 Drilled ft. Depth of completed well ...._ ._..._._1t. - R ME (6) CONSTRUCTION DETAILS: - - L Casing installed: ...f?......." Diann, from. . n.to .�.1}-..._ ft. e� Threaded❑] ............. Diana. from .._.... .._. ft.to ._._._....---- ft. - Weided{g Dlam. from .............. ft- to _.._._...._.lit. -- Perforations: Yea❑ No X L Type of perforator used. ....... ........................_........_............_--------_ 0 SIZE of perforations .. . .. . .. . In. by ........- in. perforations from .................... ft. to .....-.......,-......... ft, - ....... perforations from .................. ft. to ......................ft. _._._. perforations from ..... .. .... ft to .....................n. ttti 1 r" R Screens: Yen X No p ❑Johnse ManutMtar�r�s_Narpa ..................... ................_. ._....... 3LS1I1J.Bg$..... ,�g 1 No..........-6 Diem. ..Slot size a 3.!�... from .............. ft.to -----�^-!t- Dlam Slot sue _..........from .._..___... ft. to .-------....ft- Gravel packed: Yes❑ No 1D Sire of gravel:-------------------_._-----cc .� L Gravel placed from _......................... _. lit.to._...._..........._.._......__n. L ? Surface seal: Yes O To at depth? ..........i2 ...... ft. — ? tonCe• Material used in seal.. .. .. .__ _ _....._............... O Did any strata contain u2Gaable water? Yes❑ No a Z Type of water?"'.......... . . .... Depth of strata. ..__................ —� Method of sealing strata off..........._.._................................................_..__. - N -- (7) PUMP: manufacturer's Name... ..... .... O _......... Type: ......_................ .. ...... ----------._--------...._.......... RP........................ — �' (8) WATER LEVELS: Land-surface elevation - n above mean sea level.... ................_._..lit. 0 Static level ...... yM . ..............ft. below top of well Date. ............................ 0 Artesian pressure . .............._lba. per square Inch Date_ ..... ................ V Artesian water is controlled by.........................................etc.)................. W (CaP.valve. ) O (9) WELL TESTS: Drawdown is amount water level to `-- r.+ lowered below static level WoZlt/tartad,....__.._.._..........._._.,Is.......... Compieted................ Was a pump test made+ Yes❑ No(C If yes,by whom? .. Q► Yield: gal./min. with ft. drawdown after hrs. WELL DRILLER'$ STATEMENT: 4.6 This well was drilled under my Jurisdiction and this report is L- - true to the best of my knowledge and belief. QL Recovery data (time taken as zero when pump turned Off) (water level m measured from well top to water level) AND$RSON WELL DRILLING t7 Time Water Level Time Water Least Time water Law& NAME............................. . r....................ati.an.._..... ..... .. ........ (Person. Srm, or corporation) 4Type or pnntl .................................. .. ........... .._.... . ............................... ................ '........... . --. ... ----...... AddmuP 13...BELF W SH.a...-9 5.2$ i Dateof tee .. ........ ...................... [Sighed] . . ........ii.r................................. ....... er lest gal./min. wlth......10 ...lit. dnwdown after........1.....hre. ffii- Ball 1 DrilLr) �1f�I Artesianflow .. .......... ........ .....................g.p.m. Data...............................................__.. O 6.-8-f 7 Temperature of water...... ... Was a eharrilea]analysts made?To D No('F tJftdt 0.... ...75............................ Date................................., 19-----.._ iUaY ADDMOXAL XJIZ 'b &IR42CM6gARY) ECv 050-1.70 �' Drileap rim nt and tint Copy with WATER WELL REPORT Department of d oioffynrst Application No. Second Copy—Owner's Copy Third Copy—Drtller's Copy STAYS OF WAJU M(ITON Permit No. .... (1) OWNER: Name. @Xl _... .... Address....._ a (2) LOCATION OF WELL: county_-........ .ii,on............-.........................................I.........._.— .... .. . -_..._, ,: 5 . Seca.... . . T11.._.N.. R.t..__ .M. a Bearing and distance from section or_subdivlaton corner cz _ (3) PROPOSED USE: Domestic as Industrial 0 Municipal ❑ (10_) WELL LOG: Irrigation ❑ Test Well ❑ Other 0 rormatlon: Describe by color,character,sire of materml and structure.and } show thickness of agrtfferr and the kind and nature o/the matertat to each ? stratstm Ixrlst*ats0. with at least one entry )or sash ehanpe of forrrtatsoti• (4) TYPE OF WORK: Owner's number of well Vl iif more than one) ... ....._. ........ ............_. MATiRIAL FROM I TO New well Method: Dug [) f8ored ❑ + Deepened ❑ Cable Driven Q - --- - - - — OReconditioned 0 Rotary❑ Jolted ❑ tl+ C ILL 30 (5) DIM NS: Diameter of well ..-�+...��-st. tncha. j 0 DrlflenIT. _. .. ft Depth of completed well artZRN CLA7 BRM9 CLU _ P (6) CONSTRUCTION DETAILS: --- `p Casing installed: ... 6 0.... 206 ORAXaE,,-c� ���W •, Diem. from .. Lt. to N Egon GUT- Threaded❑ ......._......... Diam, from ft.to ............_.. tt. Welded " Dlam. from . BROfldli TILL � .. St. f;o .......-...... n. S"D AND GRAVEL 0 T Perforations: Yes❑ No L Ty"of perforator used...............................................................-......_..._.. _ 0 SIZE of perforations .. ._ .......... in. by ..._.........__........... in. 'a perforations from . ............._...... ft.to ..... ..._....... ft. perforations from ..................... ft.to ...__-......._. .... ft. perforations from .... . _ ........ ft to ..._................ (j Screens: Yea?5 Na❑ JOHNSON --- -- Ma .............. ... ............No........._.r�T --- �..i Diann. Ll. .... Slot au .. .L7., __ . .. .,... ft.to .1n�r _ fft, - Dlam. ..._ .. Slot site ........... from ..___........ ft.to ............ ft Gravel packed: Yes p No� M: Sire of gravel: ........................... L Grirel placed from.................. ft.to ............................... _. Surface seal: yes A ..o T at depths .......20._....... !t. �^ "'t'�" ^ Sidi Material used in, sea - __. ............ .............-.............. O Did any strata contain unusable water? Yes 13 Nos Z Type of water? . .... _..- Depth of strata ........ ................_.. Method of sealing strata off_..._.........._......._... ....... .......................... O (7) PUMP: Manufacturer's Name..................................... h Typr. . ._ . ._..__..........................................................H.P....................... h (8) WATER LEVELS: Land-surface elevation — AL aove mean Sea level. O Static level . I 6 . 1t.b ... below top of well Date VArtesian pressure lbs. per square inch Date............................. Artesian water is controlled by. .. — LU (Cap,valve, etc.) 0 Drawdown is amount water level Is — (9) WELL TESTS: lowered below static level a+ Work started.._...._.._........._...__.....tY_........ Completed...... .......................... 30.....-. Waa a pump test made? Yes O No jg It yes, by whom? . Yield: gal./min withT ft. drewdown after hr.. WELL DRILLER'S STATEMENT: ya This well wag drilled under my jurisdiction and this report is >` true to the best of my knowledge and belief, Q Recovery data i time taken am zero when pump turned off) (water level measured from well top to water level) f�l•F.0 DRILLING (] Time Water Level Ttme Water Lead Ttms Watee Uuel NAME.. ...oral o (Person, firm.or corporation) (Type or print) - -- --------- --""................... Adarru...PO.�A-, . 823 BELFAIR ................ ....................... ...................................... -.-.... -,....--....................... .. ........................ A 4- BtllDate of I t ... min. with. -lt. dra ......... ...- r test .._.... . Sal./ wdown after.---.............hra. ({Nell D l rip Artesian flow........_........_.... ....,.._ .......g.p.M. Date...._...........-................................ 0875 2�28—f 7 Temperature of water...._........was a ehemlcel analysts msdet Yes Q lfo Q Uce&o No. ........../.. .......................... ate.................... .......... . 19........ It111t ADDIT10NAL Z� It 1fDCMSARYl rrr oso•i.io ��s APPENDIX D SLOPE STABILITY STABLE Slope Stability Analysis System New User Project Ball Datafile: Static Bishop STABLE Version 9.03.00u Bishop 1'1 TLE Static UNITS (Metric/Imperial) I GEOMETRY DEFINITION POINTS NO. X Y 1 0.000 0.000 2 50.000 0.000 3 108.000 16.000 4 130.000 26.000 5 150.000 40.000 6 200.000 41.000 7 270.000 43.000 8 0.000 -4.000 9 50.000 -4.000 10 108.000 12.000 11 130.000 22.000 12 27.000 0.000 13 38.370 0.000 14 49.740 0.000 15 61.110 3.060 16 72.470 6.200 17 83.840 9.340 18 95.210 12.470 19 106.580 15.610 20 117.950 20.520 21 129.320 25.690 22 140.680 33.480 23 152.050 40.040 24 163.420 40.270 25 174.790 40.500 26 186.160 40.720 27 197.530 40.950 28 208.890 41.250 29 220.260 41.590 30 231.630 41.900 31 243.000 42.230 LINES Lo X Hi X SOIL 1 2 1 2 3 1 3 4 1 4 5 1 5 6 1 8 9 2 9 10 2 10 11 2 STABLE02002 MZ Associates Ltd Printed on: 15/09/08 @ 11:11:51 Page: 1 STABLE Slope Stability Analysis System New User Project : Ball Datafile: Static Bishop 11 6 2 6 7 2 SOILS SOIL NAME LINETYPE-PEN COHESION FRICTION UNIT WT. 1 Soil-1 CONTINUOUS-BLACK 0.00 32.0 136.000 2 Soil-2 CONTINUOUS-BLUE 100.00 40.0 140.000 ##tat++++aaa++aaataaa+++++a+a++++++a+a++++++aa+++++aa+aa++ PORE PRESSURE SPECIFICATION SOIL PIEZO RU EXCESS Y/N/P Value Value 1 N 0.000 0.000 2 N 0.000 0.000 PIEZOMETRIC SURFACE POINT POINT PORE PRESSURES POINT PRESSURE SLIP DIRECTION (+/- X) ++a#+#+a+++++#a++#a++sass+++++a++aa++#++}}#++++aa#+++#+}}# SLIP-CIRCLES AUTOMATIC Circle Centre Grid Extremities 259.000 } # 27.000 * * 243.000 a i 43.000 X spacing -- no. of cols (max 10)- 10 Y spacing -- no. of rows (max 20)- 20 Grid 1 Circles through point 12 Grid 2 Circles through point 13 Grid 3 Circles through point 14 Grid 4 Circles through point 15 Grid 5 Circles through point 16 Grid 6 Circles through point 17 Grid 7 Circles through point 18 STABLEOD2002 MZ associates Ltd PrinMd on: 16109M 4111:11:61 Pape: 2 1 . 00 1 . 1 0 1 . 20 1 . 30 1 . 40 1 . 50 1 . 60 1 . 70 1 . 80 1 . 90 2 . 00 8 Project Ball Datafile Static Analysis Bishop STABLE.2002 MZ Associates Ltd 1 . 00 - 110 1 . 20 1 . 30 1 . 40 1 . 50 1 . 60 1 . 70 1 . 80 1 . 90 2 . 00 8 Project : Ball Datafile Dynamic Analysis Bishop STABLE.2002 MZ Associ.tes LtC APPENDIX E EROSION CONTROL GEOTEXTILE FABRIC 2'x2' WOOD POST (TYP) GEOTEXTILE FABRIC WRAP AROUND TRENCH OR EQUIVALENT OR BETTER AND WIRE MESH TO AT LEAST ENTIRE 2 6 FT MAX. O.C. BOTTOM OF TRENCH 0.5 FT BEFORE PLACING GRAVEL 2'x2'x5' WOOD POST OR 6 FT —+� 12' DEEP, 8' WIDE TRENCH EQUIVALENT OR BETTER EXISTING FILLED WITH 3/4' TO 1 1/2' GROUND SURFACE WASHED GRAVEL 2 T DIRECTION r 1 2.5 FT 12' DEEP, 8' WIDE DIRECTION OF ER FLOW EXISTING TRENCH FILLED WITH 1 T WAT12, GROUND SURFACE 3/4' TO 1 1/2' u 2.5 FT T2.5 FT WASHED GRAVEL BOTTOM EXTENTS OF GEOTEXTILE FABRIC u]T FENCE - DETAIL _ ZFrTInN N.T.S. N.T.S. PERMANENT EROSION CONTROL NOTES- GENERAL NOTES; SOD PLACEMENT 1. SHOULD THE TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES SHOWN ON 1. SOD FOR GRASS SWALES SHALL BE MACHINE CUT AT A THESE PLANS PROVE TO BE INADEQUATE DURING CONSTRUCTION, THE CONTRACTOR 3/4-INCH UNIFORM THICKNESS AT THE TIME OF CURING. SHALL INSTALL ADDITIONAL EROSION AND SEDIMENT CONTROL FACILITIES. MEASUREMENTS FOR THICKNESS SHALL EXCLUDE TOP GROWTH AND 2. ALL EROSION AND SEDIMENT CONTROL FACILITIES AND DEVICES SHALL BE THATCH. INSPECTED DAILY AND IMMEDIATELY MAINTAINED, IF NECESSARY. 2. STANDARD SIZE SECTIONS OF SOD FOR GRASS SWALES SHALL 3. ALL EROSION AND SEDIMENT CONTROL FACILITIES AND DEVICES SHALL BE LEFT IN BE STRONG ENOUGH TO SUPPORT THEIR OWN WEIGHT AND RETAIN PLACE UNTIL THE UPSLOPE AREAS HAVE BEEN PERMANENTLY STABILIZED. THEIR SIZE AND SHAPE WHEN SUSPENDED BY THE END OF A 3 FOOT SECTION. TEMPORARY EROSION CONTROL NOTES- 3. SOD FOR GRASS SWALES SHALL NOT BE HARVESTED OR TRANSPLANTED WHEN EXCESSIVELY DRY OR WET MOISTURE FOR ALL AREAS WHICH HAVE BEEN STRIPPED OF VEGETATION OR EXPERIENCED LAND CONTENT MAY ADVERSELY AFFECT ITS SURVIVAL. DISTURBING ACTIVITIES, AND WHERE NO FURTHER WORK IS ANTICIPATED FOR A 4. SOD FOR GRASS SWALES SHALL BE HARVESTED, DELIVERED PERIOD EXCEEDING THE LISTED CRITERIA BELOW, ALL DISTURBED AREAS MUST BE AND PLACED WITHIN A PERIOD OF 36 HOURS. IMMEDIATELY STABILIZED WITH MULCHING, GRASS PLANTING OR OTHER APPROVED EROSION CONTROL TREATMENT APPLICABLE TO THE TIME OF YEAR. GRASS SEEDING SEEDING FOR RAW SLOPES ALONE WILL ONLY BE ACCEPTABLE DURING THE MONTHS OF APRIL THROUGH SEPTEMBER, HOWEVER, SEEDING MAY PROCEED WHENEVER IT IS IN THE INTEREST OF 1. BEFORE SEEDING, INSTALL NEEDED SURFACE RUNOFF CONTROL THE OWNER/CONTRACTOR, BUT MUST ALSO BE AUGMENTED WITH MULCHING, NETTING MEASURES SUCH AS GRADIENT TERRACES, INTERCEPTOR DIKES, OR OTHER APPROVED TREATMENT. SWALES, LEVEL SPREADERS AND SEDIMENT BASINS. 2. THE SEED BED SHALL BE FIRM WITH FAIRLY FINE SURFACE, DRY SEASON (MAY 1 THRU SEPTEMBER 30) -- THE CLEARING OF LAND, INCLUDING THE FOLLOWING SURFACE ROUGHENING. PERFORM ALL OPERATIONS REMOVAL OF EXISTING VEGETATION OR OTHER GROUND COVER, MUST BE LIMITED TO ACCROSS OR PERPENDICULAR TO THE SLOPE. ONLY AS MUCH LAND AS CAN RECEIVE APPROPRIATE PROTECTIVE COVER OR BE 3. SEEDING RECOMMENDATIONS, AS SHOWN BELOW, AND SHOULD BE OTHERWISE STABILIZED, AFTER HAVING BEEN CLEARED OR ❑THERWISE DISTURBED APPLIED AT THE RATE OF 120 POUNDS PER ACRE. BY NO LATER THAN SEPTEMBER 30 OF A GIVEN YEAR. UNLESS IMMEDIATE 4. SEED BEDS PLANTED BETWEEN MAY 1 AND OCTOBER 31 WILL STABILIZATION IS SPECIFIED IN THE EROSION AND SEDIMENT CONTROL PLAN, ALL REQUIRE IRRIGATION AND OTHER MAINTENANCE AS NECESSARY TO AREAS CLEARED OR OTHERWISE DISTURBED MUST BE APPROPRIATELY STABILIZED FOSTER AND PROTECT THE ROOT STRUCTURE. THROUGH THE USE OF MULCHING, NETTING, PLASTIC SHEETING, EROSION BLANKETS, 5. SEED BEDS PLANTED BETWEEN NOVEMBER 1 AND APRIL 30, FREE DRAINING MATERIAL, ETC., BY SEPTEMBER 30 OR SOONER PER THE APPROVED ARMORING OF THE SEED BED WILL BE NECESSARY, (e.g., PLAN OF ACTION. UNLESS OTHERWISE APPROVED BY THE COUNTY, SEEDING, GEOTEXTILES, JUTE MAT, CLEAR PLASTIC COVERING). FERTILIZING AND MULCHING OF CLEARED OR OTHERWISE DISTURBED AREAS SHALL BE 6. FERTILIZERS ARE TO BE USED ACCORDING TO SUPPLIERS' PERFORMED DURING THE FOLLOWING PERIODS- MARCH 1 TO MAY 15, AND AUGUST 15 TO RECOMMENDATIONS. AMOUNTS SHOULD BE MINIMIZED, ESPECIALLY OCTOBER 1. SEEDING AFTER OCTOBER I WILL BE DONE WHEN PHYSICAL COMPLETION ADJACENT TO WATER BODIES AND WETLANDS. OF THE PROJECT IS IMMINENT AND THE ENVIROMENTAL CONDITIONS ARE CONDUCIVE TO SATISFACTORY GROWTH. IN THE EVENT THAT PERANENT STABILIZATION IS NOT USE THE FOLLOWING RECOMMENDED SEED MIXTURE FOR EROSION POSSIBLE, AN ALTERNATIVE METHOD OF GROUND COVER, SUCH AS MULCHING, NETTING, CONTROL, OR A COUNTY APPROVED ALTERNATE SEED MIXTURE. PLASTIC SHEETING, EROSION BLANKETS, ETC., MUST BE INSTALLED BY NO LATER THAN SEPTEMBER 30. PROPORTIONS PURITY GERMINATION IN THE EVENT THAT CONSTRUCTION ACTIVITIES OR OTHER SITE DEVELOPMENT NAME BY WEIGHT (%) (%> ACTIVITIES ARE DISCONTINUED FOR AT LEAST 4 CONSECUTIVE DAYS, THE (%> OWNER/CONTRACTOR SHALL BE RESPONSIBLE FOR THE INSPECTION OF ALL EROSION AND SEDIMENT CONTROL FACILITIES IMMEDIATELY AFTER STORM EVENTS, AND AT REDTOP (AGROSTIS ALBA) 10 92 LEAST ONCE EVERY WEEK. THE OWNER/ CONTRACTOR SHALL BE RESPONSIBLE FOR 90 THE MAINTENANCE AND REPAIR OF ALL EROSION AN SEDIMENT CONTROL FACILITIES. ANNUAL RYE (LOLIUM MULTIFLORUM> 40 98 90 WET SEASON (OCTOBER 1 THRU APRIL 30) -- ON SITES WHERE UNINTERUPTED CHEWING FESUE 40 97 CONSTRUCTION ACTIVITY IS IN PROGRESS, THE CLEARING OF LAND, INCLUDING THE 80 REMOVAL OF EXISTING VEGETATION AND OTHER GROUND COVER, SHALL BE LIMITED (FESTUCA RUBRA COMMUTATA) TO AS MUCH LAND AREA AS CAN BE COVERED OR STABILIZED WITHIN 24 HOURS IN (JAMESTOWN, BANNER, SHADOW, KOKET) THE EVENT A MAJOR STORM IS PREDICTED AND/ OR EROSION AND SEDIMENT WHITE DUTCH CLOVER 10 96 TRANSPORT OFF-SITE IS OBSERVED. 90 (TRIFOLIUM REPENS) ALL CLEARED OR DISTURBED AREAS SHALL RECEIVE APPROPRIATE PROTECTIVE COVER OR BE OTHERWISE STABILIZED, SUCH AS MULCHING, NETTING, PLASTIC MULCHING SHEETING, EROSION BLANKETS, FREE DRAINING MATERIAL, ETC„ WITHIN 5 DAYS AFTER HAVING BEEN CLEARED OR ❑THERWISE DISTURBED IF NOT BEING ACTIVELY WORKED. 1. MATERIALS USED FOR MULCHING ARE RECOMMENDED TO BE WOOD SILT FENCING, SEDIMENT TRAPS, SEDIMENT PONDS, ETC„ WILL NOT BE VIEWED AS FIBER CELLULOSE, AND SHOULD BE APPLIED AT A RATE OF 1000 ADEQUATE COVER IN AND OF THEMSELVES. IN THE EVENT THAT ANY LAND AREA NOT POUNDS PER ACRE. BEING ACTIVELY WORKED REMAINS UNPROTECTED OR HAS NOT BEEN APPROPRIATELY 2. MULCH SHOULD BE APPLIED IN ALL AREAS WITH EXPOSED STABILIZED 5 DAYS AFTER HAVING BEEN CLEARED, ALL CONSTRUCTION ACTIVITY ON SLOPES GREATER THAN 2-1 (HORIZONTALiVERTICAL). THE SITE, EXCEPT FOR APPROVED EROSION AND SEDIMENT CONTROL ACTIVITY, SHALL 3. MULCHING SHOULD BE USED IMMEDIATELY AFTER SEEDING OR IN IMMEDIATELY CEASE UNTIL SUCH A TIME AS AFOREMENTIONED LAND AREA HAS BEEN AREAS WHICH CANNOT BE SEEDED BECAUSE OF THE SEASON. ALL APPROPRIATELY PROTECTED OR STABILIZED. AREAS REQUIRING MULCH SHALL BE COVERED BY NOVEMBER 1. SILT FENCE PROJECT/ OWNER/ LOCATION, 1. GEOTEXTILE FILTER FABRIC TYPE SHALL BE PER SPECIFIED IN THE 'STORMWATER MANAGEMENT MANUAL SINGLE FAMILY RESIDENCE FOR THE PUGET SOUND BASIN; OR APPLICABLE COUNTY STANDARDS 2. GEOTEXTILE FILTER FABRIC SHALL BE PURCHASED IN A CONTINUOUS ROLL CUT TO THE LENGTH OF GE❑TECHNICAL REPORT EACH BARRIER TO AVOID USE OF JOINTS. IF JOINTS ARE NECESSARY, FILTER FABRIC SHALL BE SPLICED TOM BALL TOGETHER ONLY AT A SUPPORT POST WITH A MINIMUM 6-INCH OVERLAP AND SECURELY FASTENED AT PARCEL 12330 33 00040 BOTH ENDS TO THE POST. MASON COUNTY, WASHINGTON 3. STANDARD FILTER FABRIC SHALL BE FASTENED USING 1' STAPLES OR TIE WIRES (HOG RINGS) 2 4 IN SPACING. 4. POSTS SHALL BE SPACED AND PLACED AT DEPTHS INDICATED IN THE DETAILS ON THIS SHEET, AND ENGINEER, DRIVEN SECURELY INTO THE GROUND. ENVIROTECH ENGINEERING 5. WIRE MESH SHALL BE 2'X2'X14 GAUGE OR EQUIVILENT. THE WIRE MESH MAY BE ELIMINATED IF 74 NE HURD ROAD EXTRA-STRENGTH FILTER FABRIC (MONOFILAMENT), AND CLOSER POST SPACING IS USED. BELFAIR, WASHINGTON 9B528 6. A TRENCH SHALL BE EXCAVATED ACCORDING TO THE DETAILS ON THIS SHEET ALONG THE LINE OF THE 360-275-9374 POSTS AND UPSLOPE FROM THE SILT FENCE. 7. SILT FENCES SHALL BE LOCATED DOWNSLOPE FROM THE CLEARING LIMITS OF THE PROJECT. ER❑SI❑N CONTROL 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: Tom Ball Permit# BLD2008-01058 Parcel# 12330-33-00040 Date(s)of the Document(s) reviewed:__September 16, 2008 (1) (a)A discussion of general geologic conditions in the vicinity of the proposed development, OK?_Yes_Comment: (b) A discussion of specific soil types OK?_Yes_Comment: (c) A discussion of ground water conditions OK?_Yes_Comment: (d) A discussion of the upslope geomorphology OK? Yes_Comment: (e) A discussion of the location of upland waterbodies and wetlands OK?_Yes_Comment: (f) A discussion of history of landslide activity in the activity in the vicinity, as available in the referenced maps and records OK? Yes_Comment: (2) A site plan which identifies the important development and geologic features. OK? Yes_Comment: (3) Locations and logs of exploratory holes or probes. OK? Yes_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? Yes_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?_Yes_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 coefficients should be a value of 0.15. OK? Yes_Comment: (7) (a)Appropriate restrictions on placement of drainage features OK?_Yes_Comment: (b) Appropriate restrictions on placement of septic drain fields OK?_Yes_Comment: (c) Appropriate restrictions on placement of compacted fills and footings OK?_Yes_Comment: (d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other slopes on the property. Page 1 of 2 Form Effective June 2008 OK? Yes_Comment: (e) Recommended setbacks from the landslide hazard areas shoreline bluffs and the tops of other slopes on the property. OK? Yes_Comment: (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. OK? Yes_Comment: (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. OK? Yes_Comment: (10) An analysis of both on-site and off-site impacts of the proposed development. OK? Yes_Comment: (11) Specifications of final development conditions such as, vegetative management, drainage, erosion control, and buffer widths. OK? Yes_Comment: (12) Recommendations for the preparation of structural mitigation or details of other proposed mitigation. OK?_N/A_Comment: Not Applicable (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? Yes Comment: Are the Documents signed and stamped?_Yes_ Type and #of License: State of Washington (Professional Engineer)#43045 If not approved, what is the next action/recommendation for further action? An internal review of the submitted Geo-Report was performed and completed on September 22, 2008 using the Mason County checklist for a Geo-Report and was found to address all the necessary criteria as stated in MCRO 17.0 10 .5. (1-13)and is therefore approved for its completeness. Reviewed on_S ember 22, 2008_ Time spent in r iew: n (1) ho SECOND REVIEW/ UPDA Reviewed by on Time spent in second review: THIRD REVIEW/ UPDATE: Reviewed by on Time spent in third review: Disclaimer: Mason County does not certify the quality of the work done in this Geological Assessment Page 2 of 2 Form Effective June 2008 Mason County Department of Community Development Submittal Checklist For a Geotechnical Report 1 'tructions: 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 +9m � �� Parcel# 12330 33 0004-0 Site Address 0© G c u +r "� + �� (1) (a)A discussion of general geologic conditions in the vicinity of the proposed development, Located on page(s) 5 (b) A discussion of specific soil types Located on page(s) S (c) A discussion of ground water conditions Located on page(s) C (d) A discussion of the upslope geomorphology Located on page(s) 3 (e) A discussion of the location of upland waterbodies and wetlands Located on page(s) 3 (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) (2) A site plan which identifies the important developfnent and geologic features. Located on Map(s) 5, ci (3) Locations and logs of exploratory holes or probes. Located on Map(S) .S, PI CAn (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) e.ola a ;r A04J3 (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 Maps) 'o rol, (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) (7) (a)Appropriate restricts on placement of drainage features Located on page(s) (b) Approptiate restrictions on placement of septic drain fields Located on pages) 1,Z (c) Appropriate restrictions on placement of compacted fills and footings Located on page(s) 7 , a 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) /� (e) Recommended setbacks from the landslide hazard areas shoreline bluffs and the tops of other slopes on the property. Located on page(s) ) Z- (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) /1 (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) 13 (10) An analysis of both on-s a and off-site impacts of the proposed development. Located on page(s) / (11) Specifications of final development conditions such as,vegetative management,drainage, erosion control, and buffer widths. Located on page(s) I Z I !� (12) Recommendations for the preparation of structural mitigation or details of other proposed mitigation. Located on page(s) /A (13) A site map drawn to scale showing the property boundaries, scale, north arrow, and the location and nature of existing and pro osed development on the site. Located on Map(s) 5;}� av� ;� . A I, / �i G kCV I GIvd-L C21AKPI 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. 1 also certify that the Geotechnical Report, dated 91/ ��`3 , and entitledI�e�O 2 �/� p �— �Ju �,n v14, �m� Iv {K -P.5 c�tQ*kGe- meets all the requirements of the Mason County Resource Ordi ante, Landslide azard 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 s r as to prevent harm to property and public health and safety. (Signature and Stamp) CLYDAI DMIRES-T N 20091 Page 2 of 2 Form Effective June 2008 Disclaimer: Mason County does not certify the quality of the work done in this Geotechnical Report.