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HomeMy WebLinkAboutGEO2018-00009 FPA - GEO Geological Review - 1/17/2018 Geuw�_000©q RECEIVED JAN 2 3 2018 615 W.Alder Street Geotechnical Report for Logging and Single Family Residence NE Courtney Creek Lane, Belfair Parcel No. 12317-34-90010 Mason County, Washington January 17, 2018 Project 417213 Prepared For: c/o Ron Godwin Joseph & Nancy Luton 1597 NE Courtney Creek Lane ,Iv c" Belfair, Washington 98528 Prepared By: Envirotech Engineering, PLLC 43045 PO Box 984 ``'��� �' 1/17/18 Belfair, Washington 98528 Phone: 360-275-9374 r � TABLE OF CONTENTS 1.0 INTRODUCTION.................................................................................................................................I 1.1 PROJECT INFORMATION.....................................................................................................................1 1.2 PURPOSE OF INVESTIGATION AND SCOPE OF WORK......................................................................... 1 2.0 SURFACE CONDITIONS....................................................................................................................3 2.1 GENERAL OBSERVATIONS..................................................................................................................3 2.2 TOPOGRAPHY......................................................................................................................................3 Z2.1 Upslope Geomorphology............................................................................................................3 2.3 SURFACE DRAINAGE...........................................................................................................................3 2.3.1 Upslope Water Bodies.................................................................................................................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.................................................................................................6 3.3.1 Groundwater............................................................................................................................... 7 4.0 ENGINEERING ANALYSES AND CONCLUSIONS.......................................................................8 4.1 SLOPE STABILITY...............................................................................................................................8 4.1.1 Slope Stability Analysis..............................................................................................................9 4.2 EROSION............................................................................................................................................10 4.3 SEISMIC CONSIDERATIONS AND LIQUEFACTION............................................................................. 10 4.3.1 Liquefaction..............................................................................................................................10 4.4 LANDSLIDE,EROSION AND SEISMIC HAZARDS CONCLUSIONS.......................................................11 4.5 LATERAL EARTH PRESSURES...........................................................................................................11 4.6 ON-SITE AND OFF-SITE IMPACTS....................................................................................................1 1 5.0 ENGINEERING RECOMMENDATIONS.......................................................................................12 5.1 BUILDING FOL^vDATION RECOMMENDATIONS................................................................................12 5.1.1 Bearing Capacity......................................................................................................................12 5.1.2 Settlement.................................................................................................................................. 13 5.1.3 Concrete Slabs-on-Grade......................................................................................................... 13 5.2 EARTHWORK CONSTRUCTION RECOMMENDATIONS......................................................................13 5.Z.1 Excavation................................................................................................................................ 13 5.2.2 Placement and Compaction of Native Solis and Engineered Fill........................................... 14 S.2.3 Retaining Wall Backjill............................................................................................................ 15 5.2.4 Wet Weather Considerations.................................................................................................... 13 53 BUILDING AND FOOTING SETBACKS................................................................................................ 15 5.4 SURFACE AND SUBSURFACE DRAINAGE........................................................................................... 15 5.5 VEGETATION BUFFER AND CONSIDERATIONS................................................................................. 16 5.6 TEMPORARY AND PERMANENT EROSION CONTROL....................................................................... 16 5.7 SEPTIC DRAINFIELDS........................................................................................................................ 17 5.8 STRUCTURAL MITIGATION............................................................................................................... 17 5.9 TIMBER HARVESTING RECOMMENDATIONS................................................................................... 17 6.0 CLOSURE............................................................................................................................................is Appendix A-Site Plan Appendix B-Soil Information Appendix C-Slope Stability Appendix D—Erosion Control 1.0 INTRODUCTION Envirotech Engineering (Envirotech) has completed a geotechnical investigation for logging and a planned single family residence located at on NE Courtney Creek Lane, identified as parcel number 1 23 1 7-34-900 1 0, Mason County, Washington. See the vicinity map on the following page for a general depiction of the site location. An initial geotechnical evaluation of the Project was conducted by Envirotech on October 13, 2017. 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. Based on this site characteristic, the proposed development will require a geotechnical report pursuant to Landslide Hazard Areas of Mason County Resource Ordinance (MCRO) 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 which, at a minimum, conforms to the applicable MCRO. 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; supporting documentation with relation to slope stability, erosion, seismic considerations, and lateral earth pressures in the Engineering Analyses and Conclusions Section; and, recommendations for foundation, settlement, earthwork construction, retaining walls, erosion control, drainage, and vegetation in the Engineering Recommendations Section. 1.1 Project Information Information pertaining to the planned development of the Project was provided by the proponent of the property. The planned development consists of a 1- or 2-story single family residence. new on-site septic system, and other ancillary features typical of this type of development. Logging will consist of selective tree harvesting. Approximate building footprint and other proposed features with relation to existing site conditions are illustrated on the Site Map provided in Appendix A of this report. 1.2 Purpose of Investigation and Scope of Work The purpose of this geotechnical investigation is to assess geological hazards, and evaluate the Project in order to provide geotechnical recommendations that should be implemented during development. The investigation included characterizing the general Project surface and subsurface conditions, and evaluating the suitability of the soils to support the planned site activities. 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 of the Project-, • Define general subsurface conditions of the site by observing subsoils within test pits Emirotech Engineering. PLLC NE Courtney Creek Lane PO BoN 984 pa-e I Parcel 12317-34-90010 Belfair. Washington 98528 Mason County. Washinston Ph. 360-275-9374 January 17.2018 r r and/ or cut banks, review geological maps for the general area, research published references concerning slope stability, and review water well reports from existing wells near the Project; • Collect bulk samples, as applicable, at various depths and locations; • Perform soils testing to determine selected index and/or engineering properties of the site soils; • 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. r y r t Seclon 17 ---lk r t � t Project ti Vicinity Map from!Mason County Website Envirotech Engineering,PLLC NE Courtney Creek Lane PO Box 984 page 2 Parcel 1 23 1 7-34-900 1 0 Belfair, Washington 98528 Mason County, Washington Ph. 360-275-9374 January 17,2018 2.0 SURFACE CONDITIONS Information pertaining to the existing surface conditions for the Project was gathered on October 13, 2017 by a representative with Envirotech. During the site visit, the type of geotechnical investigation was assessed, site features were documented that may influence construction, and site features were examined that may be influenced by construction. This Surface Conditions Section provides information on general observations, vegetation, topography, drainage and observed slope/ erosion conditions for the Project and surrounding areas that may impact the Project. 2.1 General Observations Currently, the property is vacant with an existing driveway. Vegetation on and near the Project consists primarily of cedars, firs,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 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 Plan in Appendix A in this report for an illustration of general topography with respect to the planned development. Critical descending slopes, with grades exceeding 40% appear to be within 300 feet of the planned development. The maximum critical slope is approximately 65% with a maximum vertical relief of nearly 35 feet. Ascending grades are generally located to the southeast of the planned development. These slopes are relatively minor within 300 feet of the Project, with no apparent slope grades of at least 15%. 2.2.1 Upslope Geomorphology The upland area of the property and beyond is generally situated on a hillside of alluvial and glacial origin. 2.3 Surface Drainage Runoff originating upslope of the development is mostly diverted into stream convergences. Excessive scour and erosion were observed within the streams, but not where development is expected to occur. 2.3.1 Upslope Water Bodies Although the critical slope is descending to the stream, these water features are generally located upslope from the planned development as they originate at a higher elevation. See the surface drainage section provided later in this report for additional information. Envirotech Engineering. PLLC NE Courtnev Creek Lane PO Box 984 page ; Parcel 12317-34-90010 Belfair. Washington 98528 Mason Countv. Washington Ph. 360-275-9374 January 17, 2018 2.4 Slope and Erosion Observations The slope gradients 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, hummocky ground or 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. These slope instability indicators or other 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. = e r Aerial Photo from Google Website Envirotech Engineering. PLLC NE Courtney Creek Lane PO Box 984 page 4 Parcel 1 23 1 7-34-900 1 0 Belfair, Washington 98528 Mason County, Washington Ph. 360-275-9374 January 17.2018 3.0 SUBSURFACE INVESTIGATION Information on subsurface conditions pertaining to the Project was primarily gathered on October 13, 2017 by a representative with Envirotech. Applicable information on field methods, sampling, field testing, general geologic conditions, specific subsurface conditions, and results from soil testing are presented in this section of the report. Appendix B of this report includes pertinent information on subsurface conditions for the Project, such as subsoil cross-section(s), test pit log(s), and applicable water well report(s). Water well reports were utilized to estimate ground water levels, and if sufficient, were used in identifying subsoil types. Applicable test pit locations are depicted on the Site Plan 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/ or nearby banks extending to depths of up to 6 feet below the natural ground surface. Information on subsurface conditions also included reviewing geological maps representing the general vicinity of the project, and water well reports originating from nearby properties. Soil samples were not obtained from this project. Envirotech measured the relative density of the near-surface in-situ soils by gauging the resistance of hand tools. Within testing locations, field testing results generally indicated loose to medium dense soils in the upper 48 inches, and dense soils from 48 inches to the depth of terminous. 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. The "Geologic Map of the Belfair 7.5-minute Quadrangle, Mason, Kitsap and Pierce Counties, Washington" by Michael Polenz, Katelin Alldritt, Nicholas J. Hehemann, Isablle Y. Sarikhan, and Robert L. Logan,July 2009, provides the following caption(s)for the project area: alluvial fat:—Silt, sand.gravel.and boulders,t}pically poorl%.sorted and stratified. fortis concentric lobes inhere streatns emerge from confnuig valleys and reduced gradients cause sedmient load to be deposited Subtuut Qoaf identifies relict late Holocene(or m at least one untance probably tiashon recessional)alluvial fans that resemble unit Qaf to event• Envirotech Engineering. PLLC NE Courtney Creek Lane PO Box 984 page 5 Parcel 1 23 1 7-34-900 1 0 Belfair. Washington 98528 Mason County, Washington Ph. 360-275-9374 January 17,2018 wav but form relict fans that are tied to an elevated, farrier base level(see discussion of elevated terraces and fans under Structure). Such older fvis t}picaliv are dissected by a distinctly incised modern stream channel The unit post-dates Vaslwn ice and is predotntnantIv Holocene but locally probably urcludes soiree late Pletsaxene deposits t Q9tCNX , �1� � M C]af -� � , . Oa ` Project Oaf y r Q is 9af I ogic Oaf Oa Otom$ i r Geological Map Department of Natural Resources Washington State 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 primarily described utilizing the Unified Soil Classification System (USCS)and the Soil Conservation Service(SCS)descriptions. The Project is currently composed of native soils without indications of borrowed fill. Within test pit locations, soils within the upper 6 feet of natural ground were generally observed to be moist, dark brown silty sand with gravel (SM). The soils exhibited some plasticity indicating clay within the substrata. The relative densities of the soil within selected test pits are provided above in Section 3.1. Expanded and specific subsurface descriptions, other than what is provided in this section, are provided in the soil logs located in Appendix B of this report. Envirotech Engineering, PLLC NE Courtney Creek Lane PO Box 984 page 6 Parcel 1 23 1 7-34-900 1 0 Belfair. Washington 98528 Mason County, Washington Ph. 360-275-9374 January 17,2018 According to the "Soil Survey of Mason County," by the United States Department of Agriculture, Soil Conservation Service, the site soils are described as Everett Gravelly Loamy Sand, Ed, with 0% - 5% slopes, and Saxon Silt Loam, S., with 5% - 15% slopes . The soil designations are depicted in the aerial photograph below, and descriptions are provided in Appendix B of this report. Soil Survey From I ISDA Natural Resources Conservation Service 3.3.1 Groundwater From the water well report(s)and knowledge of the general area, permanent groundwater is at least 30 feet directly below the property at the building pad location. Surface seepage or perched groundwater at shallow depths was not observed on-site, nor indicated on the well reports. Envirotech Engineering. PLLC NE Courtney Creek Lane PO Box 984 page 7 Parcel 12317-34-90010 Belfair.Washington 98528 Mason County,Washington Ph. 360-275-9374 January 17.2018 4.0 ENGINEERING ANALYSES AND CONCLUSIONS The following section includes slope stability, erosion, seismic considerations, and impacts to both on-site and off-site properties. 4.1 Slope Stability 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 with relation to current engineering protocol. 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, repeated surficial slope movements, if not repaired, may represent a threat to the structural integrity of the slope.If any slope movement arises,the slope should be inspected by an engineer. Subsequently, maintenance may be required 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' relating to soils. DNR labeled portions of within the vicinity of this project as medium and high slope instability with relation to slopes. A Resource Map from the DNR Forest Practices Application Review System is provided below: oil -# � � a . on •«,t Project -r Jr Resource Map from Washington State Department of Natural Resources Website Envirotech Engineering, PLLC g NE Courtney Creek Lane PO Box 984 page 8 Parcel 1 23 1 7-34-900 1 0 Belfair, Washington 98528 Mason County, Washington Ph. 360-275-9374 January 17,2018 SOILS—On Resource Map onh HtLdnc Soils Highly Unstable Highh•Erodible Highly Unstable fh;hly Erodible \o Data or Gravel Pits SLOPE—on Reson ve Hu only 3-9, r, Medium Slope lnstabilir. _High Slope Instability 4.1.1 Slope Stability Analysis The Simplified Bishop Method, utilizing `STABLE' software, was used to analyze the static stability of the site slopes. 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. 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, internal friction 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: Upper 5 feet soil depth Soil unit weight: 132 pcf Angle of internal friction: 30 degrees Cohesion: 200 psf Soils below 5 feet in depth Soil unit weight: 140 pcf Angle of internal friction: 40 degrees Cohesion: 400 psf Based on the slope stability analysis, unacceptable factors of safety could be present on and near the critical slope, but do not reflect conditions where development is expected to occur. For this Project, at the location of the proposed development, minimum factor of safeties for static and dynamic conditions were estimated to be 1.8 and I.I. respectively. See the slope stability information in Appendix C for a depiction of input parameters and example of outputs. Envirotech Engineering,PLLC NE Courtney Creek Lane PO Box 984 Page Q Parcel 12317-34-90010 Belfair. Washington 98528 Mason County, Washington Ph. 360-275-9374 January 17.2018 4.2 Erosion Based on the USCS description of the Project soils, the surface soils are considered moderately erodible. According to the Resource Map from the Washington State DNR, as provided above, the Project is not within terrain labeled `highly erodible.' This Project is not within an erosion hazard area as defined by the MCRO. Erosion hazard areas are those with USDA SCS designations of River Wash (Ra), Coastal Beaches (Cg), Alderwood Gravelly Sandy Loam on slopes 15% or greater (Ac and Ad), Cloquallum Silt Loam on slopes 15% or greater (Cd), Harstine Gravelly Sandy Loam on slopes 15% or greater (Hb), and Kitsap Silt Loam on slopes 15%or greater(Kc). It is our opinion that minor erosion control recommendations provided in this report is sufficient for the development of this Project, and additional engineered erosion control plans are not required. Temporary and permanent erosion control measures are 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. The Temporary and Permanent Erosion Control Section (Section 5.6) of this report consist of specific erosion controls to be implemented. Additional erosion control information and specifications may be found in the latest addition of the "Stormwater Management Manual for Western Washington." prepared by the Washington State Department of Ecology Water Quality Program. 4.3 Seismic Considerations and Liquefaction There are no known faults beneath this Project. The nearest Class 'A' or CIass `B' fault to this property is the Tacoma Fault Zone, in which is approximately 9 miles to the south of this Project. This information is based on the USGS Quaternary Fault and Fold Database for the United States. Potential landslides due to seismic hazards have been considered, and are addressed in the Slope Stability Analysis Section provided earlier in this report. Soils immediately below the expected foundation depth for this Project are generally Type D, 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. 4.3.1 Liquefaction The potential for liquefaction is believed to be low for this Project. This is based, in part, on the 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 (i.e. gravel, sand. silt). Although gravel-and silt-sized soil particles could be problematic, fine Envirotech Engineering. PLLC NE Courtney Creek Lane PO Box 984 page 10 Parcel 12317-34-90010 Belfair. Washington 98528 Mason County. Washington Ph. 360-275-9374 January 17.2018 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. 4.4 Landslide,Erosion and Seismic Hazards Conclusions DNR did not indicate historic landslide activity near the Project. Mapped slope conditions, as delineated by the Departments of Ecology and/ or Natural Resources, were considered in our slope stability assessment. Based on the proximity and severity of mapped delineations with respect to the proposed development, results of the aforesaid slope stability analysis, observed surface conditions, and other pertinent information, it is our opinion that the proposed development may occur in accordance with the recommendations in this geotechnical report. 4.5 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. 4.6 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 opinion is based on the expected site development, existing topography, existing nearby development, land cover, and adhering to the recommendations presented in this report. Future development or land disturbing activities on neighboring properties or properties beyond adjacent parcels that are upslope and/or downslope from the subject property could cause problems to the subject property. For this reason, future development or land disturbance near the subject property should be evaluated by a geotechnical engineer. Envirotech Engineering. PLLC _ NE Courtney Creek Lane PO Box 984 y page 1 1 Parcel 12317-34-90010 Belfair. Washington 98528 Mason County. Washington Ph. 360-275-9374 January 17.2018 5.0 ENGINEERING RECOMMENDATIONS The following sections present engineering 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; soil/ geologic conditions that were identified from the geotechnical investigation that is summarized in the Subsurface Investigation Section; and, Project research, analyses and conclusions as determined in the Engineering Analysis and Conclusions Section. Recommendations for the Project that is provided herein, includes pertinent information for building foundations, earthwork construction, building and/ or footing setbacks, drainage, vegetation considerations, and erosion control. 5.1 Building Foundation Recommendations Recommendations provided in this section account for the site development of a typical one- or two-story, single family residential structure. 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 based on observed field conditions and soil testing for this Project. After deriving conservative relative densities, unit weights and angles of internal friction of the in-situ soils, the Terzhagi ultimate bearing capacity equation was utilized for determining foundation width and depth. Foundation parameters provided herein account for typical structural pressures due to the planned type of development. A structural analysis is beyond the scope of a geotechnical report, and a structural engineer may be required to design specific foundations and other structural elements based on the soil investigation. Stepped foundations are acceptable, if warranted for this Project. Continuous, isolated, or stepped foundations shall be horizontally level between the bottom of the foundation and the top of the bearing strata. 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. 5.1.1 Bearing Capacity 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 that is competent and unyiclding. 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. For a bearing capacity requirement of no more than 1500 psf.. a minimum continuous footing width of 15 inches(18 inches for 2-story structures) shall be placed at a minimum of 18 inches below the existing ground surface atop unyielding soils. For a columnar load of no more than 3 tons, a circular or square isolated foundation diameter or width shall be at least 30 inches. Foundation recommendations are made available based on adherence to the remaining recommendations that are provided in this report. Alterations to the aforementioned foundation recommendations may be completed upon a site inspection by a geotechnical engineer after the foundation excavation is completed. Em irotech Engineering.PLLC NE Courtney Creek Lane PO Box 984 page 12 Parcel 123 1 7-34-900 1 0 Belfair. Washington 98528 Mason County. Washington Ph. 360-275-9374 January 17.2018 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, 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. 5.1.3 Concrete Slabs-on-Grade Interior slabs, if utilized, should be supported on a minimum of 6 inches of compacted coarse, granular material (Retained on U.S. Sieve 48 or greater) that is placed over undisturbed, competent native subgrade or engineered fill per the Earthwork Recommendations Section below. The recommendations for interior concrete slabs-on-grade as presented herein are only relevant for the geotechnical application of this Project. Although beyond the scope of this report, concrete slabs should also be designed for structural integrity and environmental reliability. This includes vapor barriers or moisture control for mitigating excessive moisture in the building. 5.2 Earthwork Construction Recommendations Founding material for building foundations shall consist of undisturbed native soils to the specified foundation depths. 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. 5.2.1 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, not as described in this report, or otherwise incompetent due to inappropriate land disturbing, or excessive water trapped within foundation excavations prior to foundation 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. F.nvirotech Engineering, PLLC NE Courtnev Creek Lane PO Box 984 page 13 Parcel 12317-34-90010 Belfair. Washington 98528 Mason County, Washington Ph. 360-275-9374 January 17.2018 5.2.2 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 required 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 horizontal foot for each foot of compacted or re-compacted fill depth beneath the foundation. See the illustration below. FOOTING COMPACTED NATIVE SOILS OR ENGINEERED 1 FILL i UN ISTURBED SUBGRAI)E 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. Because of moisture sensitivity, importing and compacting engineered fill may be more economical than compacting disturbed native soils. Engineered fill shall include having the soils retained on the No. 4 sieve crushed (angular), and should consist of the following gradation: U.S. Standard Sieve % Finer(by weight) 6" 100 3" 60— 100 No.4 20—60 No. 200 0 - 8 Table 1 Partical Size Distribution of Engineered Fill Compaction shall be achieved in compacted lifts not to exceed 6 inches for both 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. Temporary earth cuts and temporary fill slopes exceeding 4 feet in height should be limited to a slope of 2:1 (horizontal:vertical). Utility trenches or other confined excavations exceeding 4 feet should conform to OSHA safety regulations. Permanent cut and fill slopes shall be limited to a slope of 2:1, unless otherwise approved by an engineer. Envirotech Engineering,PLLC NE Courtney Creek Lane PO Box 984 page 14 Parcel 12317-34-90010 Belfair,Washington 98528 Mason County, Washington Ph. 360-275-9374 January 17,2018 5.2.3 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. 5.2.4 Wet Weather Considerations Due to the types of subsurface soils, additional provisions may be required (luring 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. 5.3 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 a 35 feet footing .- setback from the face of the nearby descending slopes exceeding 40% where the slope height is at least 20 feet. Where the slope height is less than 20 feet, then a footing setback may be reduced to 20 feet. See the figure below and the Site Plan in Appendix A for an illustration of the setbacks. ;7PJ,-T,y k, i From the illustration above, structures may be located closer to the top of slope by extending the foundation deep enough to maintain the recommended setback. In addition, the required setback may be reduced by mitigation.and subsequently would require additional geotechnical studies. 5.4 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 immediately. This may include a combination of swales, berms, drain pipes, infiltration facilities, or outlet protection in order to divert water away Envirotech Engineering, PLLC NE Courtney Creek Lane PO Box 984 page 15 Parcel 12317-34-90010 Belfair, Washington 98528 Mason County, Washington Ph. 360-275-9374 January 17.2018 from the structures to an appropriate protected discharge area. Leakage of water pipes. both drainage and supply lines. shall be prevented at all times. If impervious thresholds are exceeded per Mason County code, then engineered stormwater management plans are required for this project. The drainage engineer must coordinate with a geotechnical engineer for input with relation to slope stability prior to submitting drainage plans. If stormwater management plans are not required for this project, then the following recommendations should be followed. Both footing perimeter drains and roof drains are required for this Project. Subsurface water intercepted in the footing perimeter drains, and stormwater collected from roof drains shall be separately tight-lined to the recommended outlet. Roof and foundation drains may share a tightline if an above ground drainage outlet is allowable and a backflow preventer is installed within the pipe system in order to prevent roof water from entering the foundation area. For this project, we recommend that roof infiltration or dispersion is located outside of geotechnical setbacks as presented in this report,conforming to Mason County requirements. From a geotechnical perspective, the streams on the property may or may not induce slope instability. However, setbacks and buffers in this report are sufficient protection from this type of geological hazard. It is our opinion that if one of the streams migrate towards the planned building, the footing depth will provide immediate scour protection. Flood elevation determination is beyond the scope of this report, and it is the owner's responsibility to ensure that the finished floors are at least 1 foot above the base flood elevation. 5.5 Vegetation Buffer and Considerations For this project, we believe that a detailed clearing and grading plan is not warranted unless Mason County thresholds are exceeded, and basic vegetation management practices should be adhered to. Vegetation Buffer—Vegetation shall not be removed from the face of the critical slope (> 40%) or within a distance of 25 feet beyond the top of the slope where the slope height is at least 20 feet. This buffer may be reduced to 10 feet where the critical slope height is less than 20 feet.. 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 Site Plan in Appendix A of this report for a depiction of the vegetation buffer. 5.6 Temporary and Permanent Erosion Control Erosion control during construction should include minimizing the removal of vegetation to the least extent possible. Erosion control measures during construction may include stockpiling cleared vegetation, silt fencing, intercepting swales, beans, straw bales, plastic cover or other standard controls. Although other controls may be used, if adequate, 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 En irotech Engineering. PLLC NE Courtney Creek Lane PO Box 984 page 16 Parcel 1 23 1 7-34-900 1 0 Belfair. Washington 98528 Mason County. Washington Ph. 360-275-9374 JanuarN 17,2018 control measures are not functioning as needed, additional measures must be implemented immediately. See Appendix D 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 as necessary. 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 D. 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. 5.7 Septic Drainfields The approximate location of the 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 critical slopes. This is also based on compliance with all recommendations in this report. 5.8 Structural Mitigation With respect to landslide alleviation or slope improvements, structural mitigation is not necessary for this project. This determination is based on the anticipated improvements of the project, engineering conclusions,and compliance with all recommendations provided in this report. 5.9 Timber Harvesting Recommendations The Site Plan provides general location requirements regarding the logging of this project. This includes areas outside of the geotechnical vegetation buffers, and other areas disallowed by regulation such as stream setbacks. The selective harvesting areas encompass the entire property except for the aforementioned area that should be untouched. For areas with slopes of 15% or less, complete tree and stump removal i permitted. For areas greater than 1511o, stumps from harvested trees, ground and roots shall be minimally disturbed. Conventional equipment such as skidders and crawlers may be used for this Project. Logs shall be elevated on one end when dragging across the project, although dragging should be minimized as much as possible for this site. Timber harvesting causes a disturbance of a complex interaction between water, soil and vegetation, and allows for an increased erosion potential. Young trees should be monitored and protected from competing vegetation. Permanent erosion control, drainage facilities and slopes shall be immediately maintained. if necessary. Some conditions that may need immediate attention includes excessive erosion, scour, sloughing, significant changes to drainage patterns, new springs, new seepages or isolated areas of ground saturation. Envirotech should be notified if these situations occur. E:nvirotech Engineering,PLLC NE Courtney Creek Lane PO Box 984 page 17 Parcel 12317-34-90010 Belfair. Washington 98528 Mason County, Washington Ph. 360-275-9374 January 17. 2018 6.0 CLOSURE Based on the project information provided by the owner, the proposed development, 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. It is not recommended that a qualified engineer performs a site inspection during earthwork construction unless fill soils will influence the impending foundation. However.. if native, undisturbed subsurface conditions found on-site are not as presented in this report, then a geotechnical engineer should be consulted. 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 potentially protect life and/ or property. Semantics such as 'suggested' or `optional' refer that the associated design or specification may or may not be performed, but is provided for optimal performance. 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 neighboring properties, changes to ordinances or regulatory codes, or broadening of accepted geotechnical standards may affect the long-term 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 mechanic. Please contact Michael Staten at 360-275-9374 if you have any questions, comments. or require additional information. Sincerely, Envirotech Engineering Robert McNearny, E.I.T. Michael Staten. P.E. Staff Engineer Geotechnical Engineer Envirotech E:nginecring. PLLC _ ���� NE Courtney Creek Lane PO Box 984 page 18 Parcel 12317-34-90010 Belfair. Washington 98528 Mason County, Washington Ph. 360-275-9374 Januar,, 17. 2018 APPENDIX A SITE PLAN �SIO' N SCALE I INCH = 250 FEE 0 125 50 140 LOGGING ALLOWED OUTSIDE OF VEGETATION BUFFER GEOTECHNICAL VEGETATION BUFFERS SHOWN ON THIS SITE 25' FROM TOP OF 40'/.+ SLOPE PLAN AND OTHER WHERE SLOPE HEIGHT IS ENVIRONMENTAL/ PLANNING GREATER THAN 20 FEET SETBACKS PER COUNTY SUCH AS STREAMS, PROPERTY LINES, ETC, 10' FROM TOP OF 40Z+ SLOPE SEE REPORT FOR A➢DITIONAL WHERE SLOPE HEIGHT IS INFORMATION. LESS THAN 20 FEET BUILDING SETBACK- 10' FROM VEGETATION BUFFER 120 N N 0 100 A ` 2 yV STRE4M N \ J 4pPROXIy,1 RX) LEGEND APP E r OF 4 ,Y £p pD gr � -I-EROS 0 ONTROL UjLGDt ISSN fR OF 40,o SL LEES —� opfS SLOPE INDICATOR P BARN LOCATION OSS t 80 EXISTING CONTOUR TPjj@ TEST PIT POSSIBLE CME LOCATION NOTES POSSIBLE SEPTIC DRAINFIELD 1. EROSION CONTROL MAY BE REQUIRED FOR THIS SITE. AREA GENERAL LOCATIONS ARE DEPICTED, AND ALTERNATIVES MAY BE UTILIZED AS EXPLAINED IN THE GEOTECHNICAL REPORT. 2, CONTOURS WERE NOT PREPARED BY A LICENSED / PROJECT/ ❑WNER/ LOCATION LAND SURVEYOR. CONTOURS WERE EXTRAPOLATED FROM Tp? LOGGING & RESIDENCE A PUBLIC LD MEASUREMENITS ASDAR OEXPLAINED INURCE, AND C THE OGEOTECHNRATED ICAL GEOTECHNICAL REPORT REPORT. A Ao, LUTON 3. BOUNDARIES WERE NOT PREPARED BY A LICENSED NE COURTNEY CREEK LANE SURVEYOR. LOCATIONS OF SITE FEATURES THAT ARE PARCEL 12317-34-90010 SHOWN HERE, SUCH AS TOP OF SLOPES, TOE OF N MASON COUNTY, WASHIN T N SLOOPES, WATER FEATURES, ETC.., WITH RELATION TO ENGINEER THE PROPERTY LINES MUST BE VERIFIED BY THE OWNER, RECOMMENDATIONS IN THE GEOTECHNICAL ENVIROTECH ENGINEERING REPORT PROVIDE SETBACKS, BUFFERS, DEPTHS, ETC.. PO BOX 984 WITH RELATION TO GEOLOGIC FEATURES, NOT PROPERTY BELFAIR, WASHINGTON 98528 LINES. THESE GEOLOGIC FEATURES MAY BE LOCATED ON 360-275-9374 THE SUBJECT PROPERTY OR NEIGHBORING PROPERTIES. SITE PLAN APPENDIX B SOIL INFORMATION VERTICAL AND NORIZINTAL SCALE. I INCH - 40 FEET 40 PROPOSED HOUSE 'A SILTY SAND WITH GRAVEL & .CLAY. CONGLOMERATES SECTION A—A PROJECT/ OWNER/ LOCATION- LOGGING & RESIDENCE GEOTECHNICAL REPORT LUTON PARCEL 12317-34-90010 MASON COUNTY, WASHINGTON NOTES- ENGINEERs 1) MINOR GRADE CHANGES REQUIRED IN ORDER TO ACHIEVE POSITIVE DRAINAGE ENVIROT994 ECH ENGINEERING 2) THE SOIL PROFILE IS ACCURATE FOR THE DEPTH OF PO BOX 984 BELFAIR, WASHINGTON 98528 THE OBSERVED TEST PITS AT THE SPECIFIED LOCATIONS. 360-275-9374 LOVER 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: Luton Geotechnical Report DATE OF LOG: 10/13/2018 PROJECT NO: 17213 LOGGED BY: MCS CLIENT: Ron Godwin EXCAVATOR. N/A LOCATION: Parcel 12317-34-90010 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 ILL PI CURVE AND TEST DATA DEPTH IN 30 50 0 SM Dark brown, moist, loose to medium dense SILTY SAND with GRAVEL. Gravel is primarily well-graded and 1 subrounded. Sand is mostly fine and medium. Low plasticity. 2 3 4 Density increased with depth 5 - 6 Excavation terminated at approximately 6.0 feet 7 8 9 110 No Groundwater Encountered ENVIROTECH ENGINEERING This information pertains only 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: Luton Geotechnical Report DATE OF LOG: 10/13/2018 PROJECT NO: 17213 LOGGED BY: MCS CLIENT. Ron Godwin EXCAVATOR: N/A LOCATION: Parcel 12317-34-90010 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 SM Dark brown, moist, loose to medium dense SILTY SAND with GRAVEL. Gravel is primarily well-graded and 1 subrounded. Sand is mostly fine and medium. Low plasticity. 2 Density increased with depth 3 4 Excavation terminated at approximately 4.0 feet 5 6 7 8 9 110 No Groundwater Encountered ENVIROTECH ENGINEERING This information pertains only to this boring and should not be Geotechnical Engineering interpreted as being indicdive of the entire site. Map Unit Descnption:Saxon silt loam,5 to 15 percent slopes—Mason County.Washington Mason County, Washington Sa—Saxon silt loam, 5 to 15 percent slopes Map Unit Setting National map unit symbol. 2hmw Elevation. 0 to 200 feet Mean annual precipitation: 70 inches Mean annual air temperature: 43 degrees F Frost-free period: 100 to 120 days Farmland classification: Farmland of statewide importance Map Unit Composition Saxon and similar soils: 100 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Saxon Setting Landform: Escarpments; terraces Parent material: Glaciolacustrine deposits with a mantle of volcanic ash Typical profile H1 - 0 to 3 inches: silt loam H2- 3 to 9 inches: silt loam H3- 9 to 60 inches: silt loam Properties and qualities Slope: 5 to 15 percent Depth to restrictive feature. More than 80 inches Natural drainage class: Moderately well drained Capacity of the most limiting layer to transmit water(Ksat): Moderately high (0.20 to 0.57 in/hr) Depth to water table: About 18 to 23 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile. Very high (about 12.3 inches) Interpretive groups Land capability classification(irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C/D Other vegetative classification: Soils with Moderate Limitations (G002XN602WA) Natural Resources Web Soil Survey 1/16/2018 ® Conservation Service National Cooperative Soil Survey Page 1 of 2 Map Unit Description:Saxon silt loam,5 to 15 percent slopes—Mason County,Washington Hydric soil rating: No Data Source Information Soil Survey Area: Mason County, Washington Survey Area Data: Version 13, Sep 7, 2017 Natural Resources Web Soil Survey 1/16/2018 Conservation Service National Cooperative Soil Survey Page 2 of 2 Map Unit Description: Everett gravelly loamy sand.0 to 5 percent slopes—Mason County. Washington Mason County, Washington Ed—Everett gravelly loamy sand, 0 to 5 percent slopes Map Unit Setting National map unit symbol: 2hk6 Elevation: 50 to 500 feet Mean annual precipitation: 55 to 90 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 160 to 180 days Farmland classification: Prime farmland if irrigated Map Unit Composition Everett and similar soils: 100 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Everett Setting Landform. Terraces Parent material., Glacial outwash Typical profile H1 - 0 to 7 inches: gravelly ashy loamy sand H2- 7 to 21 inches: extremely gravelly sand H3-21 to 60 inches: very gravelly sand Properties and qualities Slope: 0 to 5 percent Depth to restrictive feature. More than 80 inches Natural drainage class: Somewhat excessively drained Capacity of the most limiting layer to transmit water(Ksat): High to very high (5.95 to 19.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile. Very low (about 2.5 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4s Hydrologic Soil Group. A Other vegetative classification: Droughty Soils (G002XN402WA) Hydric soil rating. No Data Source Information Soil Survey Areas Mason County; Washington Survey Area Data: Version 13. Sep 7. 2017 r Natural Resources Web Soil Survey 1/16/2018 Conservation Service National Cooperative Soil Survey Page 1 of 1 File Original WithE WATER WELL REPORT Notice of intent _ 127202 Department of Ecology Second Copy-Ownera Copy STATE OF WASHINGTON UNIQUE WELL 1.0 Third Copy-Orilters Copy Water Right Parma No. 0 (1) OWNER: Name Her1rey Hannigan AddrWS I3E 9-1_COUrtney C ek n., Belfair,_WA 9852; CL (2) LOCATION OF WELL:County Macon NE IM NWl1l4 see�T_23 ,N.R 1W WM (28) STREET ADDRESS OF WELL:(or nearest Address) -NE 91 C�nr rtmy Creek In-. R.Al faL, IJA 9A52-A Z TAX PARCEL NO.: _ 12320-21-01WO (3) PROPOSED USE: r Domestic 0 Induatrial E: Municipal (10) WELL LOG or DECOMMISSIONING PROCEDURE DESCRIPTION N irrigation 7 Test Well C Other Formation:Descrlbe by color,character,size of material and structure.and _ DeWater the kind and nature of ft material in each stratum penetrated.with at least (4) TYPE OF WORK: Owners number Of well(If more than one) one entry Our each change of information.Indicate all water encountered. C IC New Well Method: MATERIAL FROM TO 0 C Deepened _ Dug 71 Saed C - Reconditioned V Cable C Driven 0 C Decommission D Rotary C .jetted Top soil 0 1 (5) DIMENSIONS: Oiitmeter of weft h Inchu E Drilled196 feel. Depth of completed well 196 ft. Sand & ravel 1 1 24 (8) CONSTRUCTION DETAILS Csafnq s` I a stied: 6 Diem.rrom Brown c n r to 4 42 IS _Q.,__tt.to 1% Liner installed Diem.from tt.to ft. C Threaded Diem.from f.to tt. Fine gray sand J siltg_ �+ t wateg 42 144 „ 0 Pvtorsdons-. Yea C9 No *0 Type of perforator used C to SIZE of perforations In.by t*� wrforations from ff.to ft Screens: C Yes !%No O K-Pao Location t Manufacturer's Name ++ Type Model No. �+ Diem. Slot Size from tt.to tt. sr diem Slot Size hom ft.to_ft. C ` Gravel/Fllter packed: Cl Yes CXNo ❑Size o1 graveUsand M Material placed from f1.to R. Surface seal: M Ybs :)No To what depth? 1 h, O Material Used in seat Ata to n2 tQ _ z Did eny strata contain unusable water? a Ybs Zlo Tyw of water? Depth of strata Memod of Dealing strata oft ^.7,11 0 M PUMP: Manufacturer's Name Type: M.P. (8) WATER LEVELS: Land•surtaos elevation above mean Asa level ft. Static)" 82 ft.below top of wall Data work Started J j/ , Completed 3/_1 fj/w Artesian pressure lbs.per square inch Data W Artesian water is Controlled by (Cap.VANS,at.) WELL CONSTRUCTION CERTIFICATION: w 0 (9) WELL TESTS: Drawdown is amount water level is lowered below static W#W I contracted and'or socept responsibility for construction of f}frs wall,and ft it was a pump teat made? C Yes K No K yes,by whom? compliance with all Washington C ngton well construction DtanderW. Materials used f� Yield: oeVmin.with ft.drawdorm slier hn. and the information reported above are true to my beat knowledge and belief. Yleid: oalJmin.wah ft.drawllown after M. Type or Print Name_,ZQnB( _.—License No. 1884 L Yield oal.lmin.with f4 drawdown afar hire. (Licensed Oritler/Engineer) Recovery data(time taken ss zero when pump turned off)(water I"measured irpm Trained Name License No. C well top to water level} 0 Time Water I" Time Water Level Time Water Leal Drilling Coin Dayi Drilling- (Signed } License No. 1884 _ — ( ' ensed r/Enginser) 1-- Address -__ Belfair. WA 98528 Date of test 8a(ler test 15��.f./min.wkh 3 ff.drorwdoitm s?W_ _hra. Cpn[raclors Art" eaUmin.whh tt.drawdown after fus. Registration No. DMI;DT1100A —oate__MargbL, QQ_ Anesian flow o.p.m. Do% (USE ADDITIONAL SHEETS IF NECESSARY) Temperature of water Was a Chetnial snatysis made? O Yes (I No Eulogy is an Equal Opportunity and ANirmatnw Action employer.For spwW ECY 050.1-20(11Me) aocornmodation reeds,contact the Waror Reeouroes Program at (360)407- 6600.The TDD number is(360)407-6006 APPENDIX C SLOPE STABILITY STABLE Slope Stability Analysis System New User Project Godwin Datatile: dynami Bishop ST?B_E Version 3.03.00u Bishop .........«..........«..........«.......................... TITLE dynami UNITS (Metric/Imperial) - I GEOMETRY DEFINITION POINTS NO. X Y 1 0.000 0.000 2 50.000 0.000 3 105.000 -35.000 4 155.000 -35.000 5 15.500 0.000 6 22.030 0.000 7 28.550 0.000 8 35.080 0.000 9 41.610 0.000 10 48.130 0.000 11 54.660 -2.960 12 61.180 -7.120 13 67.710 -11.270 14 74.240 -15.420 15 80.760 -19.580 16 87.290 -23.730 17 93.820 -27.880 18 100.340 -32.040 19 106.8?0 -35.000 20 113.390 -35.000 2! 119.920 -35.000 22 126.450 -35.000 23 132.9?0 -35.000 24 139.500 -35.000 LINES Lo X Hi X SOII. 1 2 i 2 3 3 4 i .......................................................... SOILS SOIL NAME LINETYPE-PEN COHESION FRICTION UNIT WT. 1 Soi1_1 CONTINUOUS-BLACK 100.00 30.0 130.000 ......................................«........ .«..««..... PORE PRESSURE SPECIFICATION SOIL PIEZO RU EXCESS Y/N/P Value Value STABLE8=2UZ Associates Ltd Printed on: 17,0118 @11:49:41 Page: t STABLE Slope Stability Analysis System New User Project Godwin Datafile: dynami Bishop 1 N 0.000 0.000 PIE20METRIC SURFACE POINT POINT PORE PRESSURES POINT PRESSURE xx+xxxttttr+xrtxr+♦tt++tttt+tttrrrt++t+ttrtt+rrftrxrrrrraf SLIP DIRECTION (+/- X) - + ffi r}fit}r}r rf rtf xrrr+}rrflffrttflrff}trrtffxfrrtrtrrrrf rf rf SLIP-CIRCLES AUTOMATIC Circle Centre Grid Extremities 124.000 r♦rr rr•.rr.rrtr 15.500 • 139.500 w r t rrr►tfrrrrr rrr 0.000 X spacing -- no. of cola (max 10)- 10 Y spacing -- no. of rows (max 20)- 20 Grid 1 Circles through point 5 Grid 2 Circles through point 6 Grid 3 Circles through point 7 Grid 4 Circles through point 8 Grid 5 Circles through point 9 Grid 6 Circles through point 10 Grid 7 Circles through point it Grid 8 Circles through point 12 Grid 9 Circles through point 13 Grid 10 Circles through point 14 Grid 11 Circles through point 15 Grid 12 Circles through point 16 Grid 13 Circles through point i7 Grid 14 Circles through point 18 Grid 15 Circles through point 19 Grid 16 Circles through point 20 Grid 17 Circles through point 21 Grid 18 Circles through point 22 Grid 19 Circles through point 23 Grid 20 Circles through point 24 +f►rrt+f rf+++rrr.rrrf:rrf tfrrfrtr r►frrf}+:rr}r rrarwrr+r♦rr OPTIONS STABLE02002 MZ Associates Ltd Printed on: 17,0V18 @ 11:49:41 Page: 2 I I i ! i i I { i i I i f c 0 0 0 c 0 0 0 0 0 c I 1 , I I i ! 1 I i 1 4� i I j O i 0 j I rJ `9 'nP; a I I i ! 0 rJ i NP3c2 I aoa; 1 - I i f I I I i I Ii 1 � I I I ! I I ! I c O Q 0 0 0 0 0 0 0 c 1 i I i I I i � 1 I I I I 1 � I ► I � I I i I ♦ O I 1 i f I o ! f I •-+ E 0 'OGW i I � (i •d iG '. i I I I � a1 w >,; I I o � ro- .. I I APPENDIX D EROSION CONTROL r GEOTEXTILE FABRIC 2'x2' WOOD POST (TYP) GEOTEXTILE FABRIC WRAP AROUND TRENCH OR EQUIVALENT OR BETTER AND WIRE MESH TO AT LEAST ENTIRE 8 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 t/2'1 GROUND SURFACE 2�T WASHED GRAVEL or VEGETATION DIRECTION OF It 2'S�FT 12' DEEP, 8' WIDE WATER FLOW GROUND SURFACE EXISTING TRENCH FILLED WITH i T 1p• 3/4' TO 1 1/2' 2,5 FT 2.5 fT WASHED GRAVEL OR VEGETATION �8, BOTTOM f GEOTEXT LE EXTENTS FABRIOC SILT FENCE - DETAIL SILT FENCE - CROSS SECTION N.T.S. N.T.S, HAY OR STRAW MATTING ENERAL NOTES: 1. STRAW SHALL BE AIR DRIED, AND FREE FROM WEED SEEDS AND COARSE MATERIAL. SHOULD THE TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES SHOWN ON 2. APPLY AT APPROXIMATELY 75 TO 100 POUNDS PER 1000 SQUARE HESE PLANS PROVE TO BE INADEQUATE DURING CONSTRUCTION, THE CONTRACTOR FEET OF GROUND. HALL INSTALL ADDITIONAL EROSION AND SEDIMENT CONTROL FACILITIES. 3, MINIMUM THICKNESS SHALL BE 2 INCHES. ALL EROSION AND SEDIMENT CONTROL FACILITIES AND DEVICES SHALL BE 4. HAY OR STRAW IS SUBJECT TO BLOWING, KEEP MOIST OR TIED NSPECTED DAILY AND IMMEDIATELY MAINTAINED, IF NECESSARY. DOWN. . ALL EROSION AND SEDIMENT CONTROL FACILITIES AND DEVICES SHALL BE LEFT IN LACE UNTIL THE UPSLOPE AREAS HAVE BEEN PERMANENTLY STABILIZED, PERMANENT EROSION CONTROL NOTES EMPORARY EROSION CONTROL NOTES, SEEDING FOR RAW SLOPES OR ALL AREAS WHICH HAVE BEEN STRIPPED OF VEGETATION OR EXPERIENCED LAND 1. BEFORE SEEDING, INSTALL NEEDED SURFACE RUNOFF CONTROL ISTURBING ACTIVITIES, AND WHERE NO FURTHER WORK IS ANTICIPATED FOR A MEASURES SUCH AS GRADIENT TERRACES, INTERCEPTOR DIKES, ERIOD EXCEEDING THE LISTED CRITERIA BELOW, ALL DISTURBED AREAS MUST BE SWALES, LEVEL SPREADERS AND SEDIMENT BASINS. MMEDIATELY STABILIZED WITH MULCHING, GRASS PLANTING OR OTHER APPROVED 2. THE SEED BED SHALL BE FIRM WITH FAIRLY FINE SURFACE, ROSION CONTROL TREATMENT APPLICABLE TO THE TIME OF YEAR, GRASS SEEDING FOLLOWING SURFACE ROUGHENING. PERFORM ALL OPERATIONS ACCROS LONE WILL ONLY BE ACCEPTABLE DURING THE MONTHS OF APRIL THROUGH OR PERPENDICULAR TO THE SLOPE. EPTEMBER, HOWEVER, SEEDING MAY PROCEED WHENEVER IT IS IN THE INTEREST OF 3. SEEDING RECOMMENDATIONS, AS SHOWN BELOW, AND SHOULD BE HE OWNER/CONTRACTOR, BUT MUST ALSO BE AUGMENTED WITH MULCHING, NETTING APPLIED AT THE RATE OF 120 POUNDS PER ACRE, R OTHER APPROVED TREATMENT. 4. SEED BEDS PLANTED BETWEEN MAY 1 AND OCTOBER 31 WILL REQUIRE IRRIGATION AND OTHER MAINTENANCE AS NECESSARY TO RY SEASON (MAY 1 THRU SEPTEMBER 30) -- THE CLEARING OF LAND, INCLUDING THE FOSTER AND PROTECT THE ROOT STRUCTURE, EMOVAL OF EXISTING VEGETATION OR OTHER GROUND COVER, MUST BE LIMITED TO 5. SEED BEDS PLANTED BETWEEN NOVEMBER i AND APRIL 30, NLY AS MUCH LAND AS CAN RECEIVE APPROPRIATE PROTECTIVE COVER OR BE ARMORING OF THE SEED BED WILL BE NECESSARY, (e.g., THERWISE STABILIZED, AFTER HAVING BEEN CLEARED OR OTHERWISE DISTURBED , GEOTEXTILES, JUTE MAT, CLEAR PLASTIC COVERING). Y NO LATER THAN SEPTEMBER 30 OF A GIVEN YEAR, UNLESS IMMEDIATE 6, FERTILIZERS ARE TO BE USED ACCORDING TO SUPPLIERS' TABILIZATION IS SPECIFIED IN THE EROSION AND SEDIMENT CONTROL PLAN, ALL RECOMMENDATIONS. AMOUNTS SHOULD BE MINIMIZED, ESPECIALLY REAS CLEARED OR OTHERWISE DISTURBED MUST BE APPROPRIATELY STABILIZED ADJACENT TO WATER BODIES AND WETLANDS. HROUGH THE USE OF MULCHING, NETTING, PLASTIC SHEETING, EROSION BLANKETS, REE DRAINING MATERIAL, ETC., BY SEPTEMBER 30 OR SOONER PER THE APPROVED USE THE FOLLOWING RECOMMENDED SEED MIXTURE FOR EROSION LAN OF ACTION. UNLESS OTHERWISE APPROVED BY THE COUNTY, SEEDING, CONTROL, OR A COUNTY APPROVED ALTERNATE SEED MIXTURE. ERTILIZING AND MULCHING OF CLEARED OR OTHERWISE DISTURBED AREAS SHALL BE ERFORMED DURING THE FOLLOWING PERIODS MARCH 1 TO MAY 15, AND AUGUST 15 TO PROPORTIONS PURITY GERMINATIO CTOBER 1. SEEDING AFTER OCTOBER 1 WILL BE DONE WHEN PHYSICAL COMPLETION NAME BY WEIGHT(Z) (Z) (Z) F THE PROJECT IS IMMINENT AND THE ENVIROMENTAL CONDITIONS ARE CONDUCIVE 0 SATISFACTORY GROWTH. IN THE EVENT THAT PERANENT STABILIZATION IS NOT REDTOP (AGROSTIS ALBA) 10 92 90 OSSIBLE, AN ALTERNATIVE METHOD OF GROUND COVER, SUCH AS MULCHING, NETTING, ANNUAL RYE <LOLIUM MULTIFLORUM) 40 96 90 LASTIC SHEETING, EROSION BLANKETS, ETC., MUST BE INSTALLED BY NO LATER THAN CHEWING FESUE 40 97 80 EPTEMBER 30. (FESTUCA RUBRA COMMUTATA) (JAMESTOWN, BANNER, SHADOW, KOKET) N THE EVENT THAT CONSTRUCTION ACTIVITIES OR OTHER SITE DEVELOPMENT WHITE DUTCH CLOVER 10 96 90 CTIVITIES ARE DISCONTINUED FOR AT LEAST 4 CONSECUTIVE DAYS, THE (TRIFOLIUM REPENS) WNER/CONTRACTOR SHALL BE RESPONSIBLE FOR THE INSPECTION OF ALL EROSION ND SEDIMENT CONTROL FACILITIES IMMEDIATELY AFTER STORM EVENTS, AND AT MULCHING EAST ONCE EVERY WEEK. THE OWNER/ CONTRACTOR SHALL BE RESPONSIBLE FOR HE MAINTENANCE AND REPAIR OF ALL EROSION AN SEDIMENT CONTROL FACILITIES. 1. MATERIALS USED FOR MULCHING ARE RECOMMENDED TO BE WOOD FIBER CELLULOSE, AND SHOULD BE APPLIED AT A RATE OF 1000 ET SEASON (OCTOBER I THRU APRIL 30> -- ON SITES WHERE UNINTERUPTED POUNDS PER ACRE. pNSTRUCTION ACTIVITY IS IN PROGRESS, THE CLEARING OF LAND, INCLUDING THE 2. MULCH SHOULD BE APPLIED IN ALL AREAS WITH EXPOSED SLOPES EMOVAL OF EXISTING VEGETATION AND OTHER GROUND COVER, SHALL BE LIMITED GREATER THAN 21 (HORIZONTAL,VERTICAL). 0 AS MUCH LAND AREA AS CAN BE COVERED OR STABILIZED WITHIN 24 HOURS IN 3. MULCHING SHOULD BE USED IMMEDIATELY AFTER SEEDING OR IN HE EVENT A MAJOR STORM IS PREDICTED AND/ OR EROSION AND SEDIMENT AREAS WHICH CANNOT BE SEEDED BECAUSE OF THE SEASON, ALL TRANSPORT OFF-SITE IS OBSERVED, AREAS REQUIRING MULCH SHALL BE COVERED BY NOVEMBER 1, LL CLEARED OR DISTURBED AREAS SHALL RECEIVE APPROPRIATE PROTECTIVE OVER OR BE OTHERWISE STABILIZED, SUCH AS MULCHING, NETTING, PLASTIC HEFTING, EROSION BLANKETS, FREE DRAINING MATERIAL, ETC., WITHIN 5 DAYS AFTER AVING BEEN CLEARED OR OTHERWISE DISTURBED IF NOT BEING ACTIVELY WORKED, ILT FENCING, SEDIMENT TRAPS, SEDIMENT PONDS, ETC„ WILL NOT BE VIEWED AS DEQUATE COVER IN AND OF THEMSELVES, IN THE EVENT THAT ANY LAND AREA NOT EING ACTIVELY WORKED REMAINS UNPROTECTED OR HAS NOT BEEN APPROPRIATELY TABILIZED 5 DAYS AFTER HAVING BEEN CLEARED, ALL CONSTRUCTION ACTIVITY ON HE SITE, EXCEPT FOR APPROVED EROSION AND SEDIMENT CONTROL ACTIVITY, SHALL MMEDIATELY CEASE UNTIL SUCH A TIME AS AFOREMENTIONED LAND AREA HAS BEEN PPROPRIATELY PROTECTED OR STABILIZED. ILT FENCE PROJECT/ OWNER/ LOCATION, 1. GEOTEXTILE FILTER FABRIC TYPE SHALL BE PER SPECIFIED IN THE 'STORMWATER MANAGEMENT MANUAL LOGGING & RESIDENCE OR THE PUGET SOUND BASIN,' OR APPLICABLE COUNTY STANDARDS 2. GEOTEXTILE FILTER FABRIC SHALL BE PURCHASED IN A CONTINUOUS ROLL CUT TO THE LENGTH OF GEOTECHNICAL REPORT EACH BARRIER TO AVOID USE OF JOINTS. IF JOINTS ARE NECESSARY, FILTER FABRIC SHALL BE SPLICED LUTpN TOGETHER ONLY AT A SUPPORT POST WITH A MINIMUM 6-INCH OVERLAP AND SECURELY FASTENED AT PARCEL 12317-34-90010 BOTH ENDS TO THE POST. MASON COUNTY, WASHINGTON . STANDARD FILTER FABRIC SHALL BE FASTENED USING 1' STAPLES OR TIE WIRES (HOG RINGS) H 4 IN PACING. POSTS SHALL BE SPACED AND PLACED AT DEPTHS INDICATED IN THE DETAILS ON THIS SHEET, AND ENGINEER RIVEN SECURELY INTO THE GROUND. ENVIROTECH ENGINEERING . WIRE MESH SHALL BE 2'X2'X14 GAUGE OR EQUIVILENT. THE WIRE MESH MAY BE ELIMINATED IF PO BOX 984 XTRA-STRENGTH FILTER FABRIC (MONOFILAMENT), AND CLOSER POST SPACING IS USED. BELFAIR, WASHINGTON 99528 . A TRENCH SHALL BE EXCAVATED ACCORDING TO THE DETAILS ON THIS SHEET ALONG THE LINE OF THE 360-275-9374 OSTS AND UPSLOPE FROM THE SILT FENCE, 7. SILT FENCES SHALL BE LOCATED DOWNSLOPE FROM THE CLEARING LIMITS OF THE PROJECT. EROSION CONTROL 1 Mason County Department of Community Development Submittal Checklist For a Geotechnical Report Instructions: This checklist must be submitted with a Geotechnical Report and completed, signed, and stamped by the licensed professional(s) who prepared the Geotechnical Report for review by Mason County pursuant to the Mason County Resource Ordinance. If an item found to be not applicable, the report should explain the basis for the conclusion. Applicant/Owner Joseph & Nancy Luton Parcel# 12317-34-90010 Site Address XXX NE Courtney Creek Lane, Belfair (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) 6 (c) A discussion of ground water conditions Located on page(s) 7 (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) 8 (2) A site plan which identifies the important development and geologic features. Located on Map(s) Site Plan (3) Locations and logs of exploratory holes or probes. Located on Map(s) Site Plan/Soil Logs (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) Site Plan (5) A minimum of one cross section at a scale which adequately depicts the subsurface profile, and which incorporates the details of proposed grade changes. Located on Map(s) Soil Profile (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) 9 (7) (a)Appropriate restrictions on placement of drainage features Located on page(s) 15 (b) Appropriate restrictions on placement of septic drain fields Located on page(s) 17 (c) Appropriate restrictions on placement of compacted fills and footings Located on page(s) 12. 14 Page 1 of 2 Form Effective June 2008 Disclaimer: Mason County does not certify the quality of the work done in this Geotechnical Report. t f (d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other slopes on the property. Located on page(s) 16 (e) Recommended setbacks from the landslide hazard areas shoreline bluffs and the tops of other slopes on the property. Located on page(s) 15 (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) 16 (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) 16 (10) An analysis of both on-site and off-site impacts of the proposed development. Located on page(s) 11 (11) Specifications of final development conditions such as. vegetative management, drainage, erosion control• and buffer widths. Located on page(s) 15-17 (12) Recommendations for the preparation of structural mitigation or details of other proposed mitigation. Located on page(s) 17 (13) A site map drawn to scale showing the property boundaries, scale, north arrow, and the location and nature of existing and proposed development on the site. Located on Map(s) Site Plan I, Michael C Staten hereby certify under penalty of perjury that I am a civil engineer licensed in the State of Washington with specialized knowledge of geotechnical/geological engineering or a geologist or engineering geologist licensed in the State of Washington with special knowledge of the local conditions. I also certify that the Geotechnical Report. dated 1/17/18 and entitled Logging and Single Family Residence meets all the requirements of the Mason County Resource Ordinance, Landslide Hazard Section, is complete and true, that the assessment demonstrates conclusively that the risks posed by the landslide hazard can be mitigated through the included geotechnical design recommendations. and that all hazards are mitigated in such a manner as to prevent harm to property and public health and safety. (Signature and Stamp) {' 1/17/18 .44 Page 2 of 2 Form Effective June 2008 Disclaimer; Mason County does not certify the quality of the work done in this Geotechnical Report. GEO � � - ��► 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: Lb�Ire`1\ Permit#: P)a 11- 01 Parcel#: i Z 3 1 - 3 - 9 O c) U Date(s) of the Document(s) reviewed: y 1Z S / I X 1. (a) A discussion of general geologic conditions in the vicinity of the proposed development, OK? v Comment: 3 Z (b) A discussion of specific soil types OK? Comment: 3 Z (c) A discussion of ground water conditions OK? Comment: (d) A discussion of the upslope geomorphology OK? ✓ Comment: '2 . 2. (e) A discussion of the location of upland waterbodie§and wetlands OK? V Comment: 2 , 3- 1 (f) A discussion of history of landslide activity in the vicinity, as available in the referenced maps and records OK? Comment: 2. A site plan that identifies the important development and geologic features. OK? �Comment: >>to Ql4R.1 lcm S 3. Locations and logs of exploratory holes or probes. OK? I/ Comment: s � elc_h 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? v Comment: S,2= Y hh 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?JZ 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 coeffients should be a value of 0.15. OK? ✓ Comment: Ll. ( 7. (a) Appropriate restrictions on placement of drainage features OK? ✓ Comment: 5- `f (b) Appropriate restrictions on placement of septic drain fields OK? ✓ Comment: 5 (c) Appropriate restrictions on placement of compacted fills and footings. OK? ✓ Comment: s I S. Z. Z Page 1 of 2 Form Effective June 2008 (d) Recommended buffers from the landslide hazard areas shoreline bluffs and the to of other slopes. OK? ✓ Comment: 621,4c.- 0� s�� s g �vl S- (e) Recommended setbacks from the laSS clslide hazard areas shoreline bluffs and the tops of other slopes. OK? ✓ 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? 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? Comment: S 10. An analysis of both on-site and off-site impacts of the proposed development. OK? Comment: 11. Specifications of final development conditions such as, vegetative management, drainage, erosion control, and buffer widths. _ OK? ` Comment: 12. Recommendations for the preparation of structural mitigation or details of other proposed mitigation. OK? vl Comment: 5 Y A,/A 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? i/ Comment: Are the Documents signed and stamped? By whom? rc Inc Q.( s�c n License#: G License type: FIRST REVIEW VApproved ❑ Need more info. If not approved, what is the next action/recommendation for further action? Reviewed by M I,"S on f 3 I „`) Time spent in review: SECOND REVIEW/UPDATE ❑ Approved ❑ Need more info. Reviewed by , on . Time spent in second review: THIRD REVIEW/UPDATE ❑ Approved ❑ Need more info. Reviewed by , on . Time spent in third review: Disclaimer. Mason County does not certify the quality of the work done in this Geotechnical Report. Page 2 of 2 Form Effective June 2008 I i1854 ) MASON COUNTY (360)427-9670 Shelton ext. 352 COMMUNITY SERVICES DEPARTMENT (360)275-4467 Belfair ext. 352 Mason County Bldg. 8, 615 W.Alder Street (360)482-5269 Elma ext. 352 Shelton, WA 98584 www.co.mason.wa.us Ron Godwin Evergreen Forest Resources 13504 Woodside Lane SW Port Orchard,WA 98367 September 18,2017 Re: TPN 12317-34-90010 Dear Mr.Godwin, This letter is in follow up to our site visit for the Luton property.on Courtney Creek Rd,on the above referenced tax parcel. On September 13th,we walked the site as part of the review of a Class IV General FPA,which seeks to open up ground for a home,a barn and create pasture.You and the Lutons also walked the site in June with planner Kell Rowen as part of a site pre- inspection. This is an undeveloped 10 acre parcel that is bisected by two streams at three locations. One is Courtney Creek,which is classified as a Fish stream and has a 150'buffer(on each side)with an additional 15'building setback. The second stream is considered a non-fish perennial(Np)which has a 100'buffer(and an additional 15'building setback). The Np stream arches through the parcel and has an associated wetland parallel to portions of its bank. The cumulative effect of the buffers for both streams,plus the buffer for the wetland(which is undetermined)has a significant footprint on this parcel. At our meeting you gave me a new site plan(1"= 150')that shows the locations of the streams with their buffers which is very helpful,but on further inspection I see that the buffers are not drawn to scale and that in the case of Courtney Creek, it is not centered over the creek. I'm not too worried as I know that you have measured and flagged the 150'foot buffer for Courtney Creek,but the map will have to be corrected.I also noticed that the buffer for the Np does not scale out to 100'on each side. The map divides the site up into three units(1 -home site,2 - inside the arch of the Np stream plus barn site,and 3 -the old Christmas tree stand north of the Np stream). This is a helpful way to think about the site and the unique features of each unit. Unit 1: Unit I is bounded by Courtney Creek Rd to the south and west,by Courtney Creek to the north and the property line on the east.This portion of the site will be an eventual home site.The buffer for Courtney Creek has been flagged.However Unit 1 also contains slopes over 15%and over 10' tall.We talked about this in the field and you were under the impression that Kell Rowen thought that a 50'building setback would be sufficient,but she doesn't recall saying that. It may tam out that a 50'building setback for the slope(usually the 40%point)will be adequate,but we don't know that without a geological assessment or geotechnical report(full report when slopes are over 40%).To log,grade, or construct anything(including septic)within 300'of this slope will require a geo-review. I am attaching a handout of engineers known to Mason County,but you are not limited to this list. I am also attaching the submittal checklist that the engineer needs to submit with the assessmentireport. The County review fee for geo assessment/reports is$300. In between Unit 1 and 2: In between Unit 1 and 2 are Courtney Creek and the lower run of the Np stream as well as 200+ feet of combined(over lapping)buffer for these two creeks.Courtney Creek Rd runs through this area Courtney Creek is cross with an existing wooden bridge.You would like to establish a landing in the buffer between Courtney Creek and the Np stream. There is already a disturbed area in the buffer,adjacent to the existing road that could be used for this purpose.For reasons that I will explain below,this project will need a Mason Environmental Permit and a Habitat Management Plan(MEP&IMP)and this landing can be addressed in that permit. You are also interested in taking some trees from the buffer.We briefly discussed MCC 8.52.170.F.4 which reads as follows: Buffer alterations for view corridors are allowed with emphasis placed on limbing and with selective timber removal minimized to the extent possible. Proposed alterations shall be the minimum to afford views within the buffer and shall minimize shrub vegetation removal and ground disturbance while maintaining the large mature trees.Under this provision, no more than ten percent of trees in the buffer less than six inches in diameter at breast height may be cut without specific authorization from Mason County, which may allow removal up to twenty percent.View corridor improvement actions which include the cutting of trees larger than six inches in diameter at breast height will require Mason County approval prior to cutting,replacement with native tree and/or shrub plant species, and are limited to fifteen percent of such trees in the buffer. The cutting down of more than fifteen percent of such trees requires a Mason Environmental Permit from Mason County. To cut up to 15%of the trees in the buffer over 6" dbh will require a an inventory of all such trees in the buffer. Beyond that, it would have to be addressed through the MEP4IMP process(which you are going to do anyway). Unit 2: In order to harvest Unit 2,either a culvert or a bridge will have to be installed in the Np stream at the south end of the unit. Whether a culvert or a bridge,a Hydrolic Project Application(HPA) permit for the stream crossings will be required from the Washington State Dept of Fish and Wildlife using the JARPA form.Your contact at WSF&W is Josh Benton at 360-280-3572 or at Joshua.Benton@dfw.wa.gov.Work within the buffer to widen the exiting trail to accommodate either the logging or the eventual barn/pasture access,will require a Mason Environmental Permit with a Habitat Management Plan(MEP/HMP). I am attaching the form for this. Much of the length of the Np stream is bordered by some type of wetland.The edge of the wetland,as well as its classification type,need to be determined so that the buffer can be established.The buffer could be as large as 225'or as small as 40',but most likely will be 110'. The edge of the wetland itself does not appear to be as obvious on the ground as they sometimes are,so a wetland delineation and report from a qualified biologist will be essential to doing any work on Units 2 and the lower portion of Unit 3. The wetland report also is needed as a supporting document for the MEP/HIVIP for the stream crossing between Units 2 and 3. Unit 3: A second crossing of the Np stream(and the associated wetland)is required to access Unit 3, which is mostly a high and dry abandoned Christmas tree farm on a moderate slope. The environmental issues for Unit 3 are the same as for Unit 2.You talked about going with some sort of temporary crossing structure,but is seems like with all the permitting that is being done anyway,this might as well be a permanent crossing so that the Lutons can have vehicular access to the upper portion of their property. To recap,the following items are need for this FPA 1. Revised site plan (with scaled buffers for streams and wetland-let me know if you need a new base map). 2. Geological assessment or geotechnical report(with submittal checklist):Review Fee$300. 3. Mason Environmental Permit with a Habitat Management Plan for the approaches to the stream crossing, the second landing and possibly for removing trees from the buffer over and above the amount allowed under MCC 8.52.170.F.4. Review Fee$1,500 4. Wetland report to determine the edge, type and buffer of the wetland associated with the Np stream. Review Fee$160. 5.A HPA/JARPA for the two stream crossings submitted to WSF&W with a copy to Mason County. No cost. I recognize that lining up the professional services this late in the construction season will be challenging.You and the Lutons may want to regroup,work on this over the winter with an eye to having the permits in hand to do the work next spring. If you have any follow up questions,I can be reached at ext. 571 or by e-mail at mms@co.mason.wa.us. Sincerely, Michael MacSems FPA Reviewer