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HomeMy WebLinkAboutGeological Assessment - GEO Geological Review - 4/10/2018 Geological Assessment for RJ Peabody Single Family Residential Property 21 NE Schooner Court Parcel Number 12330-52-00037 Mason County, Washington April 10, 2018 Project#1863 Prepared For: Ron Thomas CLYpE RJ Peabody ��•�� WAsf, s'9, PO Box 565 �'k -- ;, Burley, Washington 98322 Prepared By: 43045 w �•t R�Q/STGR�4 X Envirotech Engineering ��S'�QNALE�G`� PO Box 984 Belfair, Washington 98528 Phone: 360-275-9374 Mason County Department of Community Development Submittal Checklist For a Geological Assessment Instructions: This checklist must be submitted with a Geological Assessment and completed, signed. and stamped by the licensed professional(s)who prepared the Geological Assessment 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 RJ Peabody Parcel# 12330-52-00037 Site Address 21 NE Schooner Court, Belfair (1) A discussion of geologic conditions in the general vicinity of the proposed development, with geologic unit designation based on referenced maps. Located on page(s) 5 (2) (a)A discussion of the ground water conditions at the site Located on page(S) 7 (b) A discussion of the estimated depth to water Located on page(s) 7 (c) A discussion of the quantity of surface seepage Located on page(S) 7 (d) A discussion of the upslope geomorphology Located on page(s) 3 (e) A discussion of location of upland waterbodies and wetlands. Located on page(S) 3 (3) The approximate depth to hard or dense competent soil, e.g. glacial till or outwash sand. Located on page(s) 5 (4) A discussion of any geomorphic expression of past slope instability (presence of hummocky ground or ground cracks, terraced topography indicative of landslide block movement, bowed or arched trees indicating downslope movement. etc.). Located on page(S) 3 (5) A discussion of the history of landslide activity in the vicinity, as available in the referenced maps and records. Located on page(s) 8 (6) An opinion on whether the proposed development is within the landslide hazard area or its associated buffer or setback and the potential for landslide activity at the site in light of the proposed development. Located on page(s) 8 (7) A recommendation by the preparer whether a Geotechnical Report should be required to further evaluate site conditions and the proposed development of the subject property. Page 1 of 2 Form Effective June 2008 Located on page(s) 11 (8) If the presence of a hazard is determined within 300 feet of the proposed development. then the following are delineated on a geologic map/site map (a) the area of the proposed development. Located on Map(s) n;a (b) the boundaries of the landslide hazard area (top, both sides, and toe), Located on Map(s) n/a (c) the associated buffers (top, both sides. and toe) Located on Map(s) n/a (d) building or other setbacks (top, both sides, and toe) Located on Map(s) n/a (9) 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 (app.k 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 Geological Assessment. dated Apr. 12, 2018 , and entitled RJ Peabody Single Family Residential Property (12330-52-00037) 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) r � �.� 4Ai 4/12/18 Disclaimer: Mason County does not certify the quality of the work done in this Geological Assessment. Page 2 of 2 Form Effective June 2008 TABLE OF CONTENTS l.0 INTRODUCTION.................................................................................................................................l l.l PROJECT INFORMATION..................................................................................................................... l l.% P'mpomE OF INVESTIGATION AND SCOPE mF WORK......................................................................... | lOSURFACE CONDITIONS....................................................................................................................3 11GcNamAL OBSERVATIONS--------------......--------------------.J l% Top{GRApBr........ .............................................................................................................................J 2I1tfnxlope Geomorphology.'—'.--.-_---'--.----._—._------.----.] 2.3 SURFACE DRAINAGE..........................................................................................................................] ll1Upland Water Bodies..................................................................................................................3 2.4 SLOPE AND EROSION --'—.----------_--.~_—'----.-~_---.3 lO SUBSURFACE INVESTIGATION.....................................................................................................5 11 FIELD METHODS,SAMPLING AND FIELD TESTING...........................................................................5 l2GEOLOGIC CONDITIONS.....................................................................................................................j 3.3 SPECIFIC SUBSURFACE CONDITIONS.................................................................................................7 j\3./ Groundwater...............................................................................................................................7 4L0 ENGINEERING CONCLUSIONS......................................................................................................W 4.1 LANDSLIDE HAZARDS.........................................................................................................................8 &1./ Landslides ondSlope Stability Analysis.....................................................................................V 4.l2 Surface and Smfwarface Drainage.............................................................................................V 4.2Emosx»N HAZARDS.............................................................................................................................V 4.3Ssismor HAZARDS............................................................................................................................ \0 4.4 OTHER CONSIDERATIONS—.---~~._----------..--'.—.~.'---------- |O WCLOSURE............................................................................................................................................ll Appendix A.' Site Plan 1.0 INTRODUCTION Envirotech Engineering (Envirotech) has completed this geological assessment for a residential property located at 21 NE Schooner Court, identified as parcel number 12330-52-00037 in Mason County, Washington (Project). As presented herein, this assessment includes information pertaining to the Project in this Introduction Section; observations of the property and surrounding terrain in the Surface Conditions Section; field methods and soils descriptions in the Subsurface Investigation Section; and. assessments for landslides. erosion, seismic hazards, and other considerations in the Conclusions Section. An initial geological/geotechnical evaluation of the Project was conducted by Envirotech without the property owner on March 25, 2018. It was determined that natural slopes between 15% and 40% were present within 300 feet of the Project. Due to these slope grades, a geological assessment is required pursuant to landslide hazard areas of the Mason County Resource Ordinance(MCRO). During the evaluation and site visit by Envirotech, surface and subsurface conditions were assessed in order to determine if further geotechnical studies are required. After completion of the field work and applicable Project research. Envirotech prepared this geological assessment. 1.1 Project Information Information pertaining to the Project was provided by the property owner's representative, and observations from a field visit by Envirotech. The proposed development is expected to consist of a new single family residence, septic system and other ancillary features. Approximate site development with relation to existing site features are illustrated in the Site Map in Appendix A. 1.2 Purpose of Investigation and Scope of Work The purpose of this geological assessment was to evaluate the Project in order to confirm that the proposed development is outside of any landslide hazard area and its associated buffers and setbacks as determined in the MCRO. The investigation included characterizing the general Project surface and subsurface conditions, and evaluating the suitability of the soils to support the planned site development. In order to fulfill the purpose of investigation, the geological geotechnical program completed for the proposed improvements of the Project include: • Review project information provided by the Project owner's representative: • Conduct a site visit to document the site conditions that may influence the construction and performance of the proposed improvements; • Define general subsurface conditions of the site by observing soils within test pit excavations. review well logs from existing wells near the Project, and evaluate geological maps depicting the site geology for the vicinity of the Project: • Perform soils testing, such as visual classifications, to detennine selected index properties of the soils; • Complete an engineering assessment supported by planned site alterations and the surface and subsurface conditions that were identified by the field investigation, soil testing, and applicable Project research; and. • Establish engineering conclusions based on findings and anticipated Project. Envirotech Engineering _ ~P RJ Peabody Geological Assessment a Ph. 360-275-9374 page 1 Parcel 12330-52-00037 Fax: 360-275-4789 Mason County,Washington April 12,2018 i i i ,b z .z F i i belqu i Project s Vicinity Map from Mason County Website i 1 3 a i i 5 Y a t t Enviroteeh Engineering RJ Peabody Geological Assessment Ph. 360-275-9374 page 2 Parcel 12330-52-00037 Fax: 360-275-4789 Mason County.Washington April 12,2018 2.0 SURFACE CONDITIONS Information pertaining to the existing surface conditions for the Project was gathered on March 25, 2018 by Michael Staten, geotechnical engineer with Envirotech. During the site visit, site features were documented that may influence construction or reveal potential geological hazards. This Surface Conditions Section provides information on general observations, vegetation, topography, drainage and slope/erosion conditions for the Project and surrounding areas. 2.1 General Observations The Project is currently vacant land. Schooner Court extends along the north side of the propem. Vegetation on and near the property consists primarily of 2"° growth 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 -v\ith a cloth tape and inclinometer. See the Site Map in Appendix A for an illustration of the general slope indicators with respect to the planned development. Ascending slopes exceeding 15% are located on and beyond the property. Slopes were variable, and average slope grades are approximately 25% with a total vertical relief of approximately 25 feet on the property. Descending grades are generally located to the east of the planned development. This slope is 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 is situated on a hillside and crest. Landforms are primarily of glacial origin. 2.3 Surface Drainage The majority of the stormwater runoff originating upslope from the anticipated development is expected to be minimal to moderate. Significant scour, erosion and sediment transport was not apparent near the Project. 2.3.1 Upland Water Bodies There are no apparent water bodies or wetlands located upslope from the planned development that would significantly influence the Project. 2.4 Slope and Erosion Observations The existing moderate slopes near the Project signal a potential landslide or erosion hazard area. Some indicators that may suggest past slope movements include: Envirotech Engineering RJ Peabody Geological Assessment Ph. 360-275-9374 page 3 Parcel 12330-52-00037 Pax:360-273 4789 Mason County.Washington April 12.2018 • 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. The above mentioned indicators, or other signs of 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 m Aerial Photo from Mason County Website Envirotech Engineering RJ Peabodv Geological Assessment Ph.360-275-9374 page 4 Parcel12330-52-00037 Fax: 360-2754789 Mason County, Washington April 12,2018 3.0 SUBSURFACE INVESTIGATION Information on subsurface conditions pertaining to the Project was gathered during research and a site reconnaissance. The site visit was accomplished on March 25. 2018 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 B has pertinent information on subsurface conditions for the Project, including test pit log(s) representative of the site soils. and water well report(s) originating from the subject property andl or nearby properties. 3.1 Field Methods, Sampling and Field Testing Information on subsurface conditions for the Project was accomplished by probing anticipated foundation areas with hand tools, and observing soils within test pit excavations and/ or earth cuts. Information on subsurface conditions also included reviewing geological maps within the Project vicinity, and water well reports originating from nearby properties. No soil samples were collected for this Project. Envirotech measured the relative density of the in-situ soils by gauging the resistance of hand tools. 3.2 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 Quaternan 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 unconfor-nably 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 County, Washington" by Robert E. Derkey, Nicholas J. Hehemann. and Katelin Alldritt, 2009.. provides the following caption(s)for this project: t s l i i i i Envirotech Engineering RJ Peabody Geological Assessment Ph.360-275-9374 page 5 Parcel 12330-52-00037 Fax: 360-275-4789 Mason County. Washington April 12,2018 1 Vaaon glacial ice-contact deposits—Sand,gravel.lodgument till.and flow till:rumor silt and clay beds:tan to gray:variably sorted:loose to compact:massive to well stratified:locally includes over-steepened beds that typically reflect sub-ice flow.but their dip may.along with >rmmall-scale shears.also have developed as collapse features or due to alaciotectonic and tectonic deformation:formed in the presence of meltwater alongside ice.generally toward the end of the glaciatiorm.and is thus conuuonly accomupartied by stagnant-ice features.such as kettles and less-orderly hununocky topography.eskers(also separately mapped as subunit Qge).and subglaciat or subaerial outwash channels.Deposits and morphologies that support conceptual association with both ice and nneltwiter are common in the map area and suggest that where unit Qgic is mapped in the presence of fluted topography,it is commonly only a few feet thick and locally could have been mapped as undifferentiated drift -init Q?d). Elsewhere.the tumit may be over 100 ft thick.Unit Qgic also includes poorly consolidated till conuuonly accompanied by underlying. angular sand and noted as-sub-glacially reworked till"by Laprade(20o3) tree oeolo2ic Settumg).especially in fluted areas that pack dead-ice features. See unit Qgo and fig.4 for discussion of siumilarities between units Qgic and Qgo(and its subunits Qgos.Qgof.and Qgol).A discrepatmcy between this nmap and the Vaughn quadrangle to the sotnth resulted where Logan and Walsh(2t707)mapped undifferentiated Quaternary deposits(taut Qu)because they lacked field expostu•ts and geomorphic signs of the dead-ice deposits that are apparent north of the boundary.Dead-ice topography north of the boundary,also reveals a sandy deposit mapped as unit Qgos by Logan and Iffalsh(2007)to Lit a facies within unit Qgic.Locally_ divided into: ©ge op � Qm Qgtf t Oa gt QPf trt i � ✓ j Qgic ' p, Om 1 r Qm Oaf 9 Qm° _ter rr' Envirotech Engineering RJ Peabody Geological Assessment Ph. 360-275-9374 page 6 Parcel 12330-52-00037 Fax: 360-2754789 Mason County,Washington i Apri 112. 2018 i 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. The Project is primarily composed of both disturbed and undisturbed native soils, with indications of substantial fill. Competent bearing soils were encountered at 18 inches below the existing native, undisturbed ground surface in locations where the ground was probed. For engineering purposes,these native soils consist of distinguishable layers,as presented below. Soils within the upper 6 feet of natural ground were observed to be primarily moist, brown poorly graded sand with silt and some gravel (SP). Expanded subsurface descriptions. other than what is provided in this section, are provided in the soil logs located in Appendix B of this report. According to the "Soil Survey of Mason County," by the United States Department of Agriculture, Soil Conservation Service (SCS), the site soils are described as Indianola Loamy Sand. It, with 5% - 15% slopes. See the soil map below, and the applicable SCS soil profile(s) in Appendix B of this report. lY Soil Survev From USDA 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 50 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 RJ Peabody_ Geological Assessment Ph. 360-275-9374 page 7 Parcel 12330-52-00037 Fax: 360-275-4789 Mason County.Washington April 12.2018 4.0 ENGINEERING CONCLUSIONS The following sections present engineering assessments and conclusions concerning the Project. These conclusions have been made available based on the planned construction activities as outlined in the Introduction Section of this report; general observations of drainage and topography as summarized in the Surface Conditions Section; and, soil conditions that were identified by the field investigation and soils testing as outlined in the Subsurface Investigation Section. Conclusions for the Project that is provided herein, includes pertinent information for landslide.erosion and seismic hazards. 4.1 Landslide Hazards For the planned development, as provided in the Introduction Section of this report, it is Envirotech's opinion that the proposed development is not subjected to or cause adverse impacts to a landslide hazard area or its associated butler or setback as defined in the MCRO. This conclusion is based on the contents provided in this report. Landslides are natural geologic processes. and structures near slopes possess an inherent risk of adverse settlement, sliding or structural damage due to these processes. Geotechnica) 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. Maintenance of the slope should 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 or property. According to the Department of Natural Resources (DNR) "LHZ — Final A-1 Map — Landslide Inventory — ?Mason Watershed, by Sarikhan. et. al., May 2007." previous landslide activity is not recorded near the project. Per the Resource Map from DNR, the Project is not within terrain labeled `highly unstable' or 'highly erodible' relating to soils. DNR labeled portions of this project as medium 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. A resource map from DNR is provided below: Envirotech Engineering RJ Peabody Geological Assessment Ph. 360-275-9374 page 8 Parcel 12330-52-00037 Fax: 360-275-4789 Mason County, Washington April 12,2018 , n Project t �� ■ 4 r s .Vfap from Washington State Department of Natural Resources Website 4.1.1 Landslides and Slope Stability Analysis Past landslide activity or high slope instability indicators near the proposed development was not revealed during the Project research. In addition. detrimental landslide activity or potential high landslide indicators were not observed during the site visit as outlined in the Surface and Subsurface Conditions Sections of this report. Due to these factors, and existing/proposed conditions, a slope stability analysis was not deemed necessary for this Project. Considering the planned constriction as summarized in the Introduction Section of this report; the aforementioned surface and subsurface conditions for the Project; the slope stability assessment provided herein; and the Engineering Conclusions provided later in this report, it is our opinion that the Project is not within a landslide hazard area, and that the proposed site alterations will not encourage a landslide hazard. 4.1.2 Surface and Subsurface Drainage This project does not appear to experience significant subsurface drainage or surface runoff. It is our opinion that groundwater or surface drainage is not a limiting factor for this Project. Any applicable drainage requirements provided within the approved plat should be adhered to. 4.2 Erosion Hazards 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 Fnvirotech Engineering RJ Peabody Geological Assessment Ph. 360-275-9374 page 9 Parcel 12330-52-00037 Fax: 360-275-4789 Mason County,Washington April 12,2018 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 (Ilb), and Kitsap Silt Loam on slopes 15%or greater(Kc). Temporary and/ or permanent erosion control measures may be required for any site when land disturbance is involved. 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 conditions and planned disturbance of this Project include wind-borne silts during dry weather, and sediment transport during prolonged wet weather. Sediment transport of disturbed soils could be from stormwater runoff or tracking off-site with construction equipment. Although an engineered erosion control plan is not warranted for this project, Best Management Practices (BMP's) should be employed during and after construction. Ordinary BMP's includes silt fencing,protection of drainage outlets and vegetating denuded areas. Erosion control information and specifications may be found in the applicable "Stormwater Management Manual for Western Washington," prepared by the Washington State Department of Ecology Water Quality Program. 4.3 Seismic Hazards 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. There are no known faults beneath this Project. The nearest Class `A' or 'B' fault to this property is the Tacoma Fault Zone. This fault is a Class 'A,' and is located approximately 7 miles to the south of the Project. This information is supported by the USGS Quaternary Fault and Fold Database for the United States. The potential for liquefaction and other earthquake induced hazards are believed to be low for this Project. This is based on subsurface conditions such as soil characteristics and the lack of a permanent and substantial shallow water table. Subgrade characteristics that particularly contribute to problems caused by seismic events include submerged and 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. 4.4 Other Considerations Conclusions in this report are based on the type and location of the anticipated development. and existing on-site and off-site conditions. Site development that significantly deviates from the anticipated improvements presented in this report, or nearby development that influences this Project may, require geotechnical design recommendations. It is our opinion that septic drainfields may be constructed on the sloping property at any location when complying with septic regulations. If structures are constructed on slopes exceeding 20%, we recommend that foundations are at least 2 feet below the ground surface. and building pad fill is benched into the subgrade at minimum bench widths of 6 feet. Envirotech Engineering RJ Peabody Geological Assessment Ph.360-275-9374 page 10 Parcel 12330-52-00037 Fax: 360-275-4789 Mason County.Washington April 12.2018 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 Envirotech is promptly notified if project and subsurface conditions found on-site are not as presented in this report so that«e can re-evaluate our recommendations. This report presents a geological/geotechnical assessment, and is intended only for the owner, or owners' representative. Furthermore, this report is only valid for the project information and location described herein. 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. Sincerer. Envirotech Engineering r 6 Michael Staten. P.E. Geotechnical Engineer Envirotech Engineering RJ Peabody Geological Assessment Ph.360-275-9374 page I 1 Parcel 12330-52-000377 Fax: 360-2754789 Mason County,Washington April 12.2018 APPENDIX A SITE PLAN 33��yy N ^'Z D t�'i��CrINC Xf mG IN1rm0 yN A�AOyN CaA 33�Z�.<j2�f'i D Nt'1maa� mrK�oZu�$ mad `"702^ANO�CpQ py 'b 2f O ?mNff'y1ty ZA bN`p*y2 �Onrr<y�y2�„i�� r.i DfT1�SNr1 Gym AAGGGOz�^�^m is N 2 C m m D n C 2^Z mh Gy m K S C�A vDi pz FM-Amrp 9r1N � Z yK N OK�r N Z C 'yp�Z ^ZKmm X NAr'$c+ �Zfm'rrg�fO r'�t�i�i< I Vv -'rmir�iarn� y WM Xric, ,rol NND AC DKr K7°m A= K N=m DG O -o ° x\ \ \ 2 ^ Y I+ co n o \ 7C) Cl a $ m m Z \ K o m D \ O 0-1 C 70 (-1f V) Mrl \ / m x-0 m M ❑ ❑ X ^� o -0 m m -0 C - v rurZi� Ll _ ❑ D -I 0 m N A='Z �20 oK Z_ -izDml= Im Z L5 K(A A ` L, Z t"'m z z m -i fTt aZ $o r 3 r t77 3 N n z � D r� A mD -I ra- z co M Z m o m m K APPENDIX B SOIL INFORMATION TEST PIT LOG TEST PIT NUMBER TP-1 PROJECT: SFR Geological Assessment DATE OF LOG: 3/25/2018 PROJECT NO: 1864 LOGGED BY: MCS CLIENT: RJ Peabody EXCAVATOR: N/A LOCATION: Parcel 12330-52-00037 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 IUSCS DESCRIPTION LL PI CURVE AND TEST DATA DEPTH N 10 30 50 0 SP-SM Brown, moist, medium dense POORLY GRADED SAND with SILT and some gravel. Sand is primarily medium. Non 1 plastic. 2 3 (SP) Decreasing silt 4 5 Excavation terminated at approximately 6.0 feet 7 8 9 10 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: SFR Geological Assessment DATE OF LOG: 3/25/2018 PROJECT NO: 1864 LOGGED BY: MCS CLIENT: RJ Peabody EXCAVATOR: N/A LOCATION: Parcel 12330-52-00037 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 SP-SM Brown, moist, medium dense POORLY GRADED SAND with SILT and some gravel. Sand is primarily medium. Non 1 plastic. 2 3 - - (SP) Decreasing silt 4 5 =< 6 Excavation terminated at approximately 6.0 feet 7 8 9 10 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. Soil Map—Mason County.Washington Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI Ee Everett gravelly loamy sand.5 59.3 41.0% to 15 percent slopes Ib Indianola loamy sand.5 to 15 82.2 56.8% percent slopes Se Saxon silt loam,5 to 15 3.2 2.2% percent slopes Totals for Area of Interest 144.7 108.0%;i -rW' Natural Resources Web Soil Survey 4/11/2018 Conservation Service National Cooperative Soil Survey Page 3 of 3