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HomeMy WebLinkAboutGEO2013-00030 for BLD2013-00359 - BLD Engineering / Geo-tech Reports - 7/9/2013 07-17-13P03 : '' RCV Geotechnical Report for Joe Galando Retaining Wall 10911 NE North Shore Road, Belfair Parcel No. 32224-50-00083 Mason County, Washington July 9, 2013 Project# 1360 Prepared For: Joe Galando LYDe 3124 SW 171 S` Street WAS s'9, Seattle, WA 98166 �p / Prepared By: -f 9//3 P 43045 k4 Envirotech Engineering OA F�.lSTER� G��w PO Box 984 r�DNAt Belfair, Washington 98528 Phone: 360-275-9374 Fax: 360-275-4789 r 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: /9' Permit# IN / 9 Parcel# �/ U 0 Date(s) of the Doc ent(s�rOiewed: - �,/V417 L P-V 1, (1) (a)A discussion of general geologic conditions in the vicinity of the proposed development, OK? Comment: (b) A disc sion of specific soil types OK?Comment: (c) A dirComment: sion of ground water conditions OK? (d) A disc sion of the upslope geomorphology OK?Comment: (e) A disc ssion of the location of upland waterbodies and wetlands OK? 11 Comment: (f) A discussion of history of landslide activity in the activity in the vicinity, as available in the refer ced maps and re rds OK? V Comment: g f- to (2) A site n which identifies he importanrvelopment and geologic features. OK? Comment: (3) Locati s and logs of exploratory di robes. OK? Comment: (4) The ar of the proposed develop t, the boundaries of the hazard, and associated buffers and setbacks phall be delineated (t , th es, and toe)on geologic map of the site. OK? V Comment: /� (5) A minimum of one cross section at a ficale which a6Auately depicts the subsurface profile, and which inc orates the details of r po d rade chap ��gj��, OK? Comment: 6�/ (6) A description and results of slolie stab4lity analyse6 Ilerformed 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 saXty factor is 1.1. and the quasi-sta c analysis coeffients should be a value of 0.15. OK? Comment: (7) (a)Approp ate restrictions on placeme t f drainage features OK?/Comment: (b) Appropriate restrictions on placement of septic drain fields OK? Comment: (c) Approp late restrictions on placement of compacted fills and footings OK? r Comment: (d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other slopes on the property. Page 1 of 2 Form Effective June 2008 1 OK? Comment: l� (e) Recommended setbacks fikorn the landslide hazard areas shoreline bluffs and the tops of other sl es on the property. OK? LZ Comment: q (8) Recommendations for the preparaVon1bf a detailed clearing and grading plan which specifically identifies vegetation to be removed, a schedule for vegetation removal and replanting, and the method oyvegetation 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 fro erosion, landslide and harmful construction methods. OK? �7// Comment: / (10) An analysis/of both on-site --site impacts of the proposed development. OK? Comment: (11) Specifics ions of final development conditions such as, vegetative management, drainage, erosion co9keol, and buffer widt OK? Comment: (12) Recommendations for the pre aration of structural mitigation or details of other proposed mitigation. OK? Comment: (13) A site m p drawn to scale showing the property boundaries, scale, north arrow, and the location and nature f existing and pro os deve pment on the site. OK?Comment: Are the Documents signed and stamped? c Type and #of License:�C/4�(����/ If not approved, what is the next action/recommendation for further action? Reviewed by on Time spent in review: SECOND REVIEW/ UPDATE: Reviewed by on Time spent in second review: THIRD REVIEW/ UPDATE: Reviewed by on Time spent in third review: Disclaimer: Mason County does not certify the quality of the work done in this Geological Assessment Page 2 of 2 Form Effective June 2008 Mason County Departments of Community Deveiopmen �itbmirrai :.:ieGKi6Si for a Geoiecnnicat Repo,z instructions: This checklist must be submitted with a Geotechnical Report and completed_siened, and stamped Uy the licensed professional(s)who prepared the Geoiechnical Report for review by Mason County pursuant to the f=:iason COuaty an iten. found'to be not eapplicable, tine report should explain the basis for the concirrsion- Applicant/Owner ,,TQLk- (X41c(,,d-o Parcel# 32�ZZq--Sr?-0,,� �� Site A%ddre s /0 // A� Ael/A �1J�f�Z4 , C/6m' e- (1) (a)A discussion of genera geologic conditions in the vicinity of the proposed development: Located on page(s) G' (b) A discussion,of specific SOR types Located on Page(s)_ 7 (c) A discussion of ground water conditions Located an page(S) (d) A discussion of the upslope gec;mor phology `uc:aied on page(s) (e) A discussion.of'he locatin of upland waterbodies and wetlands Located on page(-) (i`jj r,uiscussior:of iusiory of ianasrde activity in the activity in the vicinity,as available in the referenced maps and records L cvcjcd on page(s, (2) A site plan'which identifies the im crtant develop nt and geologic features. Located on Map(s) 57,� 1 cto � (3) Locations and logs of expl 1orat/ry hobs o-r`probes. _vtaieci ui s ivic�is /'��>1 1 o cr > (4) The area of the proposed development, the boundaries of the hazard, and associated buffers and setbacks shall be delineated,(tflp�;yboth sides,and toe)on a'geologic map of the site. Located on i ) � Mapk's ,AC- /'four (5) A minirnurri of one cross section at a scale v hich adequately depicts the subsurface profile,and tcrh ich incorporates the details-of p�r(Q��jc,sed grade changes. rs,/,1e- 6 A P escnption and re-sultS cr-slope stabi '/al J ,-L ( � iltt:3i,alyj�S perfarmett irr:?�:t•h!static aFmd S8!S.T.io:o__. conditions_Analysis should examine worst case-failures_—the anahtsis should include the i.,:::yi vi�3 iJlil?�'�"/J_�S•. F?''t)��"a5 E.N�.s�S_ t�'3e�i3e'tlfroN.b�ii sb Fc safety-factor is`G_5),the minimum, seismic safety factor is 1.1.and tl"re quasi-static anzysis coefHents should be a value of 0-15. Located on page(s) fj�_cl � I II (7) (a).Appropriate restrictions on placement of drainage features Lacaied on page(s) /� tL i Aocronriate;ast^c:ions on place nani of sepfic dr aeZ fields Located on pages) / ,c) .:1 pi-opriale restrictions on©iacer+meni or compacted fills and footings Located on pages? /c,7 Page 1 of 2 Form Effective June 2008 aDisclairner: h4ason County does not c ertifv the nualiiy of the work done in this ni k—<A; (d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other slopes on the proper . Located on page(s) e Recomme nded d setbacks from the landslide hazard areas shoreline bluffs and the tops of other siopes on the property. Located on page(s) f QJ (8) Recommendations Tor the preparation of a detailed clearing and grading peer i w- IGIh si.ie61&;a1ly identifies vegetation to be removed, a schedule for vegetation removal and replanting, and the method of vegetation removal. Located on page(s) I�? (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, iandslides and harmful construction methods. Located on page(s) !Z (iu) An analysis of both on-site and off-site impacts of the proposed development. Located on page(s) /4' (-i i) Specifications of final development conditions such as, vegetative management, drainage, erosion control, and buffer widths. Located on page(s) /40 (12) Recommendations for the preparation of structural mitigation or details of other proposed mitigation. Located on page(s) (13) A site map drawn to scale stowing the property.boundaries,scale.north arrow, and the location and nature of existing n�prgFsed development on the site. of-cried-ys i viral s c 'p ((C41 hereby certify under penalty of perjury inat i am a civil eriginesr iicensed -in the State of Washington wM speciaihmd knowiedge of geotec5mnioallyeologicai a-tgina rig or 6 gc;,logist or angin�-ing gadogist lip�sied iaa U ie Stag of aas�aWr : _ : that�: Report, dated 2!'l3 . and entitled J IO e ietees'S ail file reqi&-env erlw ua`-Ule Mason County R °rce Ordinance.tw.dslide Hazard SecUen,is complete and flue,that the assessment demons ies conclusively that the risl'cs posed by the landslide hazard can be aimiugated ttiirough the included gauleuisr'icai desigia rel[;C emaletadr._�iiS,Qihi ereu celi hazei-dS are cai gaied ire slam a itlanner as t3 pre en ..- �props a'ap ??may -P "A P r '✓ ` 0 V I` -y�R j / 719113 43045 O ru �, FGt�rERti 1� P _ Page 2 of 2 Form Effective June 2008 tSS(ai ?cr_ nA S^n v�ffnty `dces:lot card"-f F,�.a quality of the'wor ii tach , s done in tflis ^^v«. ,r rr, TABLE OF CONTENTS 1.0 Introduction 2 1.1 Project Information 2 1.2 Purpose of Investigation and Scope of Work 3 2.0 Surface Conditions 4 2.1 General Observations 4 2.2 Topography 4 2.2.1 Upslope Geomorphology 4 2.3 Surface Drainage 4 2.3.1 Upslope Water Bodies 4 2.4 Slope and Erosion Observations 5 3.0 Subsurface Investigation 6 3.1 Filed Methods,Sampling and Field Testing 6 3.2 General Geologic Conditions 6 3.3 Specific Subsurface Conditions 7 3.3.1 Groundwater 8 4.0 Engineering Analyses and Conclusions 9 4.1 Slope Stability 9 4.1.1 Slope Stability Analysis 11 4.2 Erosion 12 4.3 Seismic Considerations and Liquefaction 12 4.3.1 Liquefaction 13 4.4 Landslide,Erosion and Seismic Hazard Conclusions 14 4.5 Lateral Earth Pressures 14 4.6 On-Site and Off-Site Impacts 14 5.0 Engineering Recommendations 16 5.1 Building Foundation Recommendations 16 5.1.1 Bearing Capacity 16 5.2 Earthwork Construction Recommendations 16 5.2.1 Excavation 16 5.2.2 Placement and Compaction of Native Soils and Engineered Fill 17 5.3 Building and Footing Setbacks 18 5.4 Surface and Subsurface Drainage 18 5.5 Vegetation Buffer and Considerations 18 5.6 Temporary and Permanent Erosion Control 18 5.7 Septic Drainfields 18 5.8 Structural Mitigation 18 6.0 Closure 19 Appendix A—Site Plan Appendix B—Soil Information(Soil Profile;Soil Logs;Well Reports) Appendix C—Slope Stability Input&Output Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 1 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-275-4789 July 9,2013 1.0 INTRODUCTION Envirotech Engineering (Envirotech) has completed a geotechnical investigation for a recently constructed retaining wall located at 10911 NE North Shore Road, identified as parcel number 32224-50-00083, Belfair,Mason County,Washington. See the vicinity map on the following page for a general depiction of the site location. The geotechnical investigation was conducted at the request of the proponent of the property,Joe Galando, in support of the development as detailed below. The development, as provided herein, and the surrounding area,are identified in this report as the Project. An initial geotechnical evaluation of the Project was conducted by Envirotech on June 28, 2013. 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 development of the Project was provided by the proponent of the property during the geotechnical investigation. Other Project information was obtained by Envirotech. Existing development consists of a single family residence, detached garage, septic system, and other ancillary features. The new development, and subject of this geotechnical report, consists of a modular block retaining wall system. The modular blocks are 2ftx2ftx4ft in size,pre-manufactured with concrete.The retaining wall system is tiered,with an apparent 10 feet maximum tier height,and over 100 feet in length.The retaining wall has been designed by Austin Engineering. The retaining wall with relation to existing site conditions are illustrated on the Site Map provided in Appendix A of this report. Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 2 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-275-4789 ,July 9,2013 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 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 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. Project C—rao .- HOOD CANAL m 19 1 i t I � � A _ Sc r RE PDKE8 RD �— _ q2� 49 JI � �HM1gbitib �bt 722�R2M1 25 lilt) � 39 0 Vicinity Map from Mason County Website Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 3 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-275-4789 July 9,2013 2.0 SURFACE CONDITIONS Information pertaining to the existing surface conditions for the Project was gathered on June 28, 2013 by Michael Staten, geotechnical engineer with Envirotech. During the site visit, the type of geotechnical investigation was assessed, site features were documented that may influence construction, and 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 The property is accessed from North Shore Road, an existing paved roadway. The Project is currently developed land as previously mentioned. The access road extends through the southern 1/3 of the property, and Hood Canal borders the property to the south. Beyond the property, rural residential development exists.Vegetation on and near the Project consists primarily of secondary growth firs, cedars, madronas, 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 slopes,with grades exceeding 40%,are located upslope from the development.Due to the upslope ravine,grades are variable.The total vertical height is approximately 350 feet. 2.2.1 Upslope Geomorphology The upland area of the property is situated on a hillside of glacial origin. 2.3 Surface Drainage Stonmwater runoff originating upslope from the development appears to primarily channel within the ravine, and is expected to be extreme during high intensity rainfall. There is an existing retention pond located about 50 feet upslope from the retaining wall for mitigating high flows and sediments. Stormwater from the retention pond is routed out through two 12-inch outlet pipes and bypasses the site.Overflow appears to bypass the retaining wall. 23.1 Upslope Water Bodies There are no apparent water bodies or wetlands located upslope from the planned development that would significantly influence the Project. The ravine shows signs of heavy flow,but appears to not significantly influence the retaining structure. Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 4 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-2754789 July 9,2013 2.4 Slope and Erosion Observations The slope grades 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. Outwash and debris indicates upslope soil erosion. Tree leaning/bowing, and indications of past landslides are evident on the ascending slopes. Indications of deep-seated slope problems were not observed during the site visit. NEgy,N r m L Project R a t � r Aerial Photo from Mason County Website Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 5 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-275-4789 July 9,2013 3.0 SUBSURFACE INVESTIGATION Information on subsurface conditions pertaining to the Project was primarily gathered on June 28, 2013 by Michael Staten, geotechnical engineer with Envirotech. Specific 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 water well report(s). Water well reports were utilized to estimate ground water levels, and if sufficient, were used in identifying subsoil types. Additional well reports than what is provided in this report may be available from Envirotech upon request. 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 extending to depths of up to 4 feet below the existing ground surface, and observing cut slopes of up to 4 feet within the vicinity of the property. 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 24 inches, and very dense soils from 24 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 uncomfortably 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 Skokomish Valley and Union 7.5-minute Quadrangles, Mason County, Washington' by Michael Polenz, Jessica L. Czajkowski, Gabriel Legorreta Paulin, Trevor A. Conteras, Brendon A. Miller, Maria E. Martin, Timothy J. Walsh, Robert L. Logan, Robert J. Carson, Chris N. Johnson, Rian H. Skov, Shannon A. Mahan, and Cody R. Cohan, June 2010, provides the following caption(s)for the project area: Qpd, Possession Drift-Compact, gray, non-sorted, non-stratified till and glacial marine sediments.Also includes beds of glacial outwash. Possession till resembles Vashon till, and where the surface rill overlies the Whidbey Formation, it is possible that some of the exposures mapped as Vashon till are actually Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 6 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-275-4789 July 9,2013 Possession drift. The age of the Possession lies beyond the limit of radiocarbon dating and is unknown at present;the drift probably represents an early Wisconsinan or pre-Wisconsinan glaciation. Qaf,Qoaf Alluvial fan-Silt,sand,gravel,and boulders;typically poorly sorted and stratified;forms concentric lobes where streams emerge from confining valleys and reduced gradients cause sediment load to be deposited. Subunit Qoaf identifies relict late Holocene(or in at least one instance probably Vashon recessional)alluvial fans that resemble unit Qaf in every way but form relict fans that are tied to an elevated,former base level (see discussion of elevated terraces and fans under Structure). Such older fans typically are dissected by a distinctly incised modem stream channel.The unit post-dates Vashon ice and is predominantly Holocene but locally probably includes some late Pleistocene deposits. r am! Oafs {2gd Oa Qgic gic f Qa _ , QPd %t Qgt rQga 21 "4a 24 �Q ti eQga OafProject C 4 Oaf w i - � •: Qg+c 31-1 {gip f- 'ikT1156 --- - -- -- �, r Qua mpum 0aga WW Geological Map. Source: usgs.gov/maps 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 Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 7 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-275-4789 July 9,2013 locations. Soils for this project were primarily described utilizing the Unified Soil Classification System(USCS)and the Soil Conservation Service(SCS)descriptions. test pit locations, soils within the upper 4 feet of natural ground were moist,brown silty sand with gravel(SM). Soils below the upper 4 feet layer to a depth of 40 feet below the ground surface we believe to be mostly gray, low moisture, silty sand with gravel (SM), locally known as hardpan. The hardpan may extend to depths greater than 50 feet. This is based on nearby well reports, site geology,and/or knowledge of the general area. 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. According to the "Soil Survey of Mason County," by the United States Department of Agriculture, Soil Conservation Service, the lowland site soils are described as Everett Gravelly Sandy Loam, Ek, with 15% - 30% slopes. The soil designations are depicted in the aerial photograph below,and descriptions are provided in Appendix B of thisreport. �1 4 Project r. I VKIK {. ��� Sri � `,�4i, r:1�1�C"l�. r'Zr,[[,3,rr.''�•cj .� Soil Survey From USDA Natural Resources Conservation Service 33.1 Groundwater From the water well report(s)and knowledge of the general area, permanent groundwater is at least 40 feet directly below the property at the building pad location. Perched groundwater at shallow depths was not observed on-site, nor indicated on the well reports. However, some groundwater is expected to flow directly above the hardpan during some or all wet seasons. Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 8 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-2754789 July 9,2013 4.0 ENGINEERING ANALYSES AND CONCLUSIONS The following sections present engineering analyses and conclusions with relation to the existing conditions and proposed improvements of the Project. This section includes slope stability, erosion, seismic considerations, lateral earth pressures, 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, excessive and/or repeated surficial slope movements, if not repaired, may represent a threat to the structural integrity of the slope. If this situation does arise, the slope shall be inspected by a geotechnical 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 Coastal Zone Atlas of Mason County,Washington,the Project is within and near terrain labeled `unstable' regarding potential landslide activity. Unstable slopes are generally prone to landslides due to high grades and accommodating geology.Historically,unstable terrains have been known for landslides. However, this site is considered inherently hazardous due the existing geology and/ or topography, and additional analyses and recommendations concerning the slopes are presented herein.A Stability Map from the Coastal Zone Atlas for the general area of this Project is provided below: Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 9 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax: 360-275-4789 July 9,2013 Slope stability O R^' Stable ar ``-/^ Intermediate V Modified a C,' Unstable IIV Unstable(old slide) O • Unstable(recent slide) - t j6 Public land survey O Pro ect Township/Range/Section B Land—er(2006)O High intensity developed t a Medium intensity a"" developed t.ow Intensity developed J l ! p Developed open space Cultivated Pasture/Kay I > r Grassland Deciduous forest � Evergreen forest Mixed forest I /l Scrub/shrub Palustrine forested , wetland Palustrine scruh/shrub wetland Palustrine emergent wetland Estuarine forested = wetland Estuarine scrub/shrub ...-1-4 Add map data 0 0.2 0.4mi Map from Washington State Department of Ecology Website According to the Resource Map from the Washington State Department of Natural Resources (DNR), the Project is within terrain labeled `unstable' relating to soils. DNR labeled portions of this project as medium and high slope instability with relation to slopes. This delineation is primarily dependent upon slopes and convergence. Secondly, lithology and precipitation are modeled within this delineation. In summary, this designation is based on mapping without field observations or knowledge of the specific site geology or soils.A Resource Map from the DNR Forest Practices Application Review System is provided below: Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 10 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-2754789 July 9,2013 ."a J�Aa' Vic'::1 r A i T ..W ry t 170 00 � 170 02 16 4. / % : 1 nY 2 �115280 y 1705282 _ =w hCOJf;Cl .s 1 , :-' 3 Puget Sou nd �2 05168 1705202 t + t G �` Lr $Puget Sound r Resource Map from Washington State Department of Natural Resources Website 4.1.1 Slope Stability Analysis Based on site geology, a non-circular slope stability analysis should be performed. However, the Simplified Bishop Method (circular analysis), as presented herein, was utilized. Although the method of circles does not fit the site conditions, Envirotech certifies that our analysis is more conservative for these project conditions than other conforming slope stability models. For this Project and level of geotechnical investigation, our conclusions or recommendations would not be changed by this variation in analysis. Where applicable,our slope stability analysis utilizes the subsurface angle of repose. Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 11 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-275-4789 July 9,2013 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: 0 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, minimum factors of safety were determined to be less than 1.33 relative to static slope failures, and less than 0.83 with relation to seismic conditions. See the slope stability information in Appendix C for a depiction of input parameters and example of outputs. 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). Because development is complete, the establishment of vegetation is all that is required for this project.We believe that engineered erosion control plans are required. 43 Seismic Considerations and Liquefaction There are no known faults beneath this Project. The nearest Class `A' or Class `B' fault to this property is the Tacoma Fault Zone, in which the distal end is approximately 2 miles to the northeast of this Project. This information is based on the USGS Quaternary Fault and Fold Database for the United States. Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 12 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-275-4789 July 9,2013 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. 43.1 Liquefaction The potential for liquefaction is believed to be"Very low to 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 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. Ground Response Liquefaction Susceptibility High Project _ Moderate to high Moderate Low to moderate Low Very low to low Very low t Bedrock Peat Ice 1 faater Resource Map from Washington State Department of Natural Resources Website Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 13 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-2754789 July 9,2013 4.4 Landslide,Erosion and Seismic Hazards Conclusions DNR did not indicate previous 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 an evaluation of the shoreline recession rate, it is our opinion that the proposed development should occur in accordance with this geotechnical report. a ra Rd - DIY 1�— Landslides Landslides,1:24,000 Scale Jr'3Q5 Lade 11"I.wn Project Bbct feN or loppp Deeris flow Dell", slide antl amancnes-se Deep-seated:Deepated composde: Deep-seated eartttMw:Deep-seated rotational:Deep-seated translatbnal OO -Muya .,,—oncentrated 9—s =5 � Shalbw undrfferentteted 1 ` Landslides,1:100,000 Scale �-� LandM.es.t'100,f100 Scale L.r^ • �� ilea 7 1 as vo Resource Map from Washington State Department of Natural Resources Website 4.5 Lateral Earth Pressures Retaining walls are the subject of this geotechnical report. However, the retaining wall system is complete, and engineered by others. Our assessment includes landslide, erosion and seismic hazards. 4.6 On-Site and Ott 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 Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 14 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-2754789 July 9,2013 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 Joe Galando Geotechnical Report PO Box 984 page 15 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-2754789 July 9,2013 5.0 ENGINEERING RECOMMENDATIONS The following sections present engineering recommendations for the improvements of the Project, if further work is necessitated. These recommendations have been made available based on the new 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 the modular block retaining wall. 5.1.1 Bearing Capacity Existing in-situ soils for this Project indicates that the structure can be established on any foundation deemed adequate by the structural engineer. Foundations shall be established on relatively undisturbed native soil. Alternatively, foundations may be constructed on selective re-compacted native soil or compacted engineered fill as described in the Earthwork Construction Recommendations Section of this report. For a bearing capacity requirement of no more than 2000 psf, foundations shall be placed at a minimum of 18 inches below native soils or on top of engineered fill. 51 Earthwork Construction Recommendations Founding material 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, Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 16 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-2754789 July 9,2013 compacted, and suitable before placement of additional native soil, engineered fill or structural concrete. 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 I FILL 71 I I UNDISTURBED SUBGRA2 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 Particle 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 90% 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 Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 17 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-2754789 July 9,2013 and fill slopes shall be limited to a slope of 2:1, unless otherwise approved by an engineer. 5.3 Building and Footing Setbacks The factor of safety for slope stability is sufficient for a zero feet retaining wall setback from the nearby ascending slopes exceeding 40%. 5.4 Surface and Subsurface Drainage From a geotechnical standpoint, existing site drainage is adequate for mitigating surface runoff problems that may affect the retaining wall. In addition, the retaining wall will not generate or create channels of significant runoff. The internal stability of the retaining wall may or may not require a drainage collection system, and is assumed to have been considered by the engineer of the retaining wall. 5.5 Vegetation Buffer and Considerations For this project, we believe that a detailed clearing and grading plan is not warranted, and basic vegetation management practices should be adhered to. Vegetation shall not be removed from the face of the critical slope. 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. 5.6 Temporary and Permanent Erosion Control Erosion control during construction appears to have been adequate. Permanent erosion in the form of hydroseeding and mulching, if necessary, should be established within all denuded areas. The natural establishment of vegetation may be adequate. If sediments are found to be exiting the site,additional erosion control measures must be employed. 5.7 Septic Drainfields Septic drainfields are not an element of this project. 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. Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 18 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax: 360-2754789 July 9,2013 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. By developing the property and following the recommendations provided in this report, the property owner(s)shall be required to acknowledge in writing the risks inherent in developing in a geologic hazard area,to accept the responsibility of any adverse effects which may occur to the subject property or other properties as a result of the development, and to agree to convey the knowledge of this risk to persons purchasing the site by filing a notice on the property title. The services described in this report were prepared under the responsible charge of Michael Staten, a professional engineer with Envirotech. Michael Staten has appropriate education and experience in the field of geotechnical engineering in order to assess landslide hazards, earthquake hazards,and general soil mechanics. Please contact Michael Staten at 360-275-9374 if you have any questions, comments, or require additional information. Sincerely, EnviroteclyEngineering Michael Staten,P.E. Geotechnical Engineer Envirotech Engineering Joe Galando Geotechnical Report PO Box 984 page 19 10911 NE North Shore Road Belfair,Washington 98528 Parcel 32224-50-00083 Ph. 360-275-9374 Mason County,Washington Fax:360-2754789 July 9,2013 APPENDIX A SITE PLAN A SCALE, 1 INCH = 100 FEET 0 25 50 100 APPROXIMATE LOCAL TOP OF 407+ SLOPES 1L � Y VEGETATION NOT TO EXISTING 4' HIGH BE VED FRON RETENTION POND CRITICAL SLOPES UNLESS R GEOTECHNO AL REPQR` RETENTION WALL BLOCKS 4'x2'x2' :F EXISTING ASPHALTED APPROXIMATE TOE OF 40%+ OPES / 24' VIDE ROAD Ilk NTS ,l RET�INING WALL TP 27 LOCKS LONG �E �24 BLOCKS LONG1��' 70� (,n EXISTING QAr RAGE E ST NG 8 H SOILS- MEDIUM DENSE SILTY SAND WITH GRAVEL (SM) �� N- HOOD CANAL OVERLYING VERY DENSE ALPINE GLACIAL DEPOSITS NOTES, PROJECT/ OWNER/ LOCATION, 1. EROSION CONTROL MAY BE REQUIRED FOR THIS SITE. GENERAL LOCATIONS SINGLE FAMILY RESIDENCE ARE DEPICTED, AND ALTERNATIVES MAY BE UTILIZED AS EXPLAINED IN THE GEOTECHNICAL REPORT GEOTECHNICAL REPORT. 2. CONTOURS WERE NOT PREPARED BY A LICENSED LAND SURVEYOR. JOE GALANDO CONTOURS WERE EXTRAPOLATED FROM A PUBLIC LIDAR SOURCE, AND 10911 NE NORTHSHORE ROAD INCORPORATED FIELD MEASUREMENTS AS EXPLAINED IN THE GEOTECHNICAL LEGEND PARCEL 32224 50 00083 REPORT. MASON COUNTY WASHINGTON 3. BOUNDARIES WERE NOT PREPARED BY A LICENSED SURVEYOR. LOCATIONS TEMPORARY ENGINEER, OF SITE FEATURES THAT ARE SHOWN HERE, SUCH AS TOP OF SLOPES, TOE ++ +EROSION CONTROL ENVIROTECH ENGINEERING OF SLOOPES, WATER FEATURES, ETC.., WITH RELATION TO THE PROPERTY PO BOX 984 BELFAI LINES MUST BE VERIFIED BY THE OWNER. RECOMMENDATIONS IN THE --a SLOPE INDICATOR R, WASHINGTON 98528 GEOTECHNICAL REPORT PROVIDE SETBACKS, BUFFERS, DEPTHS, ETC.. WITH BELFAI5-9374 RELATION TO GEOLOGIC FEATURES, NOT PROPERTY LINES. THESE GEOLOGIC 80-- EXISTING CONTOUR FEATURES MAY BE LOCATED ON THE SUBJECT PROPERTY OR NEIGHBORING EST PIT PROPERTIES. TPI T SITE PLAN APPENDIX B SOIL INFORMATION 4 SCALE, I INCH = 100 FEET 0 25 50 100 v IM CMTOIG AETEMON FM 4'NIGH OETA00f WALL 16 140 4'KTwm KTANING WN.LS it Hm ACTANNG WALL EXISTING ASPHALTED in 24' WIDE ROAD NE NORTHSHORE ROAD too sN EXISTING HOUSE so 60 VLRT OEM ALP= 4ACFAL OV08TO CM 4 HOOD IO CANAL NOTES, PROJECT/ OWNER/ LOCATION, 1. EROSION CONTROL MAY BE REQUIRED FOR THIS SITE. GENERAL LOCATIONS SINGLE FAMILY RESIDENCE ARE DEPICTED, AND ALTERNATIVES MAY BE UTILIZED AS EXPLAINED IN THE GEOTECHNICAL REPORT GEOTECHNICAL REPORT. 2. CONTOURS WERE NOT PREPARED BY A LICENSED LAND SURVEYOR. JOE GALANDO CONTOURS WERE EXTRAPOLATED FROM A PUBLIC LIDAR SOURCE, AND 10911 NE NORTHSHORE ROAD INCORPORATED FIELD MEASUREMENTS AS EXPLAINED IN THE GEOTECHNICAL LEGEND PARCEL 32224 50 00083 REPORT, MASON COUNTY WASHINGTON 3. BOUNDARIES WERE NOT PREPARED BY A LICENSED SURVEYOR. LOCATIONS TEMPORARY ENGINEER: OF SITE FEATURES THAT ARE SHOWN HERE, SUCH AS TOP OF SLOPES, TOE ++ +EROSION CONTROL ENVIROTECH ENGINEERING OF SLOOPES, WATER FEATURES, ETC- WITH RELATION TO THE PROPERTY PO BOX 984 BELFAI LINES MUST BE VERIFIED BY THE OWNER. RECOMMENDATIONS IN THE SLOPE INDICATOR R, WASHINGTON 98528 GEOTECHNICAL REPORT PROVIDE SETBACKS, BUFFERS, DEPTHS, ETC., WITH BELFAI5-9374 RELATION TO GEOLOGIC FEATURES, NOT PROPERTY LINES. THESE GEOLOGIC --80-" EXISTING CONTOUR FEATURES MAY BE LOCATED ON THE SUBJECT PROPERTY OR NEIGHBORING TPle TEST PIT SITE PLAN PROPERTIES. TEST PIT LOG TEST PIT NUMBER TP-1 PROJECT: Joe Galando Geotechnical Report DATE OF LOG: 06/28/2013 PROJECT NO: 1360 LOGGED BY: MCS CLIENT: Joe Galando EXCAVATOR: N/A LOCATION: Parcel 32224-50-00083 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 Brown, moist, loose to medium dense SILTY SAND with GRAVEL. Gravel is primarily well-graded and subangular. 1 Sand is mostly medium. Low plasticity. 2 3 Light brown, dense 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 indicitive of the entire site. Stan cord No. W 0 61317 File Da"riOriginal tentorad logyirst with WATER WELL REPORT UMQUE WELL I.D-1 ARV 919 Dspsrtmern a Ecology 8ecorrd Copy—Owner's Copy STATE OF WASHINGTON Third Copy—Driller•■Copy Wetter Right Permit No. �.i 0 (I) OWNER: Name Steve Justiss ,ft.._ NE 11271 N Shore Rd Selfair, WA 98528 �I sZ 0 (7) LOCATION OF WELL: County Mason SE ,,. SE ,w sec 23 T 2 2111,to 3W wM_ (20) STREET ADDRESS OF WELL tar memo aarlrwl N F 11271 71 N Shore R ci B e l f a i r, WA 98928 (3) PROPOSED USE: N Dorneabe Indwurel ❑ Municipal C (18) WELL LOG or ABANDONMENT PROCEDURE DESCRIPTION ❑ Irrigation Test WON Q Other O Formation- Describe I»toter,character. size of material and at. urs.and show thkhneae of aquifers H El DeWater and the Idnd and nature of the material in each shatum penetrated.with at 4"one entry for each change o1 ink malwn Owner's number Of Wall r (4} TYPE OF WORK: (N more then one) MATERIAL FROM TO C Abandoned Ll New we" N Metftod:Dug❑ Bored❑ 0 2 0 G Deepened O C Driven❑ Gravel Reconditioned❑ Rotary Jetted C) C 0 C (5) DIMENSIONS: Diameter at wag 6 _ Ind May - Drilled__ 100 fee,. Depth of compte,ed well 1 Q0 —d- _ 0 16. (6) CONSTRUCTION DETAILS: 4- Casing Installed: _ 6 —• Diem.from 0 ft.to—A 5 n. & sand wl water 90 100 _C Welded LX Diem.from n. Liner mstased u — d) Ttseaded ❑ Diem-from— Perforations: Yes❑ No 0 L Type of perforator used SIZE of perforations— in.by in. _ 10 — perorations from ft.to ft. R _ Perforations Iran fl to ft- i�.r i perforations from_ ft.to n- lQ f�L - n Scream: Yee t3 No❑ Manufacturer's Name Cirink _ Type C- _' _model NO. Slot size 40 from n.m 100 n. a.a Diem. —Slot size tram ft to ft R Grevw packed; Yes❑ No Ej Size of gravel i Gravel placed from ft.to n_ R I�1 r Surfsoe sew: Yea[� No❑ To what dapd,7�$ R. Material used in seal _Ran t n n i LP O Did any strata contain unusable wataO Yes❑ No Ejj Z Typo of woof? Depth of WOO—. (h McCrod of sealing strata off —— (7) PUMP: Manutacwr9r c Name G r l 1 n d f c) Type: -- S ll D. H.P. 10 9 5 I (8) WATER LEVELS: Land-surface eleveton Wart Sleeted 7 5 9 5 ,9. cernpleted 7 t9 above meen see level h. 0 static level 20 n below too of was Dam WELL CONSTRUCTOR CERTIFICATION: V Artesian pressure - _.-. ft.Par square inch DR" W Amason wow is controlled by _ I constructed and/or accept responsibillfy for construction of this well, and its �v'v compliance with all Washington well construction standards.Materials used and 0 the information reported above are true to my best knowledge and belief. (9) WELL TESTS: Drawdown is amount water level is iowered below static level r Was a pump Net made?Yes❑ No If yes.by whom?_- C [� NAMp ,�yt s DrlllinQqC.. Yield: gal./mwithin.w n.drawdown after hrs_ IPEneON, oR CORP .y..) -- (TYPE OR PROM Yi „ .. Address B (signed) C c.- Uoer►se No.706 2 Q. Recovery data(trine taken as zero when pump tuned off)(water level measured from WON (WIELE aRLLER) top to crater level) Q Time Water Level Time Water Level Time Water Level Contractor's — _ Ntsgis n D T 1 1 0A Dare my 1995. 19— t i (USE ADDITIONAL SHEETS IF NECESSARY) Date of test Bailer last 16 _gal.lmin.with y n.drawdown char 1 hrs Ecology is an Equal Opportunity and Affirmative Action employer.For spe- Atrtest_ gel./min.with stem set at ft.for` clal accommodation needs,contact the Water Resources Program at(206) Artesian Now 9-P-m- Data 4D7-6600.The TDD number is(206)407-6006. Temperature of water Was a chemical analyse made? Yee❑ No ECY 050-t-20(9W)••I '411W' 0 a a Y WATER WELL REPORT ECOLOGY Original&V copy-Ecology, 2"copy-owner, 3 copy-driller CURRENT , Notice of Intent No.W 236879 Vf Construction/Decommission("x"in circle)Z-79 5Cj C 0 Construction Unique Ecology Well ID Tag No. ALH 631 r � ❑ Decommission ORIGINAL INSTALLATION Water Right Permit No. Notice of Intent Number Shawn Hill O Property Owner Name C PROPOSED USE: ❑rr Domestic ❑ industrial ❑Municipal O ❑Dewater ElIrrigation ElTest Well Elother Well Street Address 251 Southridge Dr. 4W TYPE OF WORK:Owners number of well(if more than one) City Tahuya County Mason cc Q New well ❑ Reconditioned Method: ❑Dug [I Bored ❑ Driven E ❑ Deepened E Cable DR. ❑ Jetted LocationNF 1/4-1/4 SE 1/4 See23 Twn22 R 3 Ewan ❑ Check 6. DIMENSIONS:Diameter of well inches,drilled 07 ft (s,t,r Still REQUIRED) Or One 0 Denth of comolatd well 307 ft. C CONSTRUCTION DETAILS Lat/Long Lat Deg Lat Min/Sec Casing ❑x Welded 6 Diam.from+I ft.to 302 ft. Long Deg Long Min/Sec C Installed: ❑Liner installed Diem.from R.to R_ 1.+ ❑Threaded Diem.From ft.to R. Tax Parcel No.(Required) 321137700100 L Perforations: ❑Yes []No CONSTRUCTION OR DECOMMISSION PROCEDURE Type 6fjierro7ar6r used -' - - Formation:Describe try coiur,character,size of maieriai and structure."""ate K"u ati.i SIZE of perfs in.by in.and no.of perfs from ft,to ft. nature of the material in each stratutn penetrated,with at least one entry for each change C of information. (USE ADDITIONAL SHEETS IF NECESSARY.) Screens: 0 Yes ❑No M K-Pac Location 300 Manufacturers Name Johnson MATERIAL FROM TO Reay ti brown clay with gravel 0 12 Type stainless Model No. Gray ti55 Diarn.5" Slot size 20 from 302 ft.to 307 ft. ll 12 ft.to ft. Cemented sand&gravel with some water SS 70 Diam. Slot size from 70 UFrker ed: Yes >< Brown silts 70 7S Grave pads ❑ ❑No Size of = 7` 128 Materials placed from ft.to ft. Brown till 128 169 Surface Seal: ❑x Yes ❑ No To what depth? 5.0 ft. Gray till Material used in seal Be[onite Brown till 169 293 Brown sand&gravel with water 293 307 LDid any strata contain unusable water? ❑Yes ❑x No - - Type of water? Depth of strata •Method of sealing strata off 'PUMP,Manufacturers Name Type: H.P. v WATER LEVELS:Land- rf a elevation above mean sea level ft 4V Static level R.below top of well Date ALI Artesian pressure lbs.per square inch Date A i O Artesian water is controlled by (cap,valve,etc.) C):r T WELL TESTS:Drawdown is amount water level is lowered below static level Was a pump test made? ❑ Yes ❑ No If yes,by whom? O Yield. galhnin with ft,drawdown after brs. i Yield: gal./min with ft.drawdown after hrs. !Tt 5 Yield: gal/min.with ft,drawdown after hrs. T V Recovery data(time taken as zero when pump turned of0(water level measured from well Ll top to water Irvel) G7 i " OTime Water Level Time Water Level Time Water Level 1 rnn Fir C 0� Anj EDate of test O C �..a Bailer Test gal.hnin.with ?2 _R.drawdown after hrs. L dAinest gal./min.with stern set at ft.for hrs. r'11J Artesian flow g.p.m. Date L.a Temperature of water Was a chemical analysis made? ❑ Yes I]No Start Date 3/16/2010 Completed Date 4/12/2010 1v C WELL CONSTRUCTION CERTIFICATION: I constructed and/or accept responsibility for construction of this well,and its compliance with all Washington well construction standards.Materials used and the information reported above are true to my best knowledge and belief QDriller❑EngineerOTrainee Name(Print) Matt ennin en DnllingCompany Davis Drilling Driller/Engineer)'Trainee Signature -en Iq A 0 ot Address P.O.Box 536 Driller or trainee License No. 30 City,State,Zip Belfair WA 98528 IF TRAINEE:Driller's License No, Contractor's Drillers Signature Registration No DAVISDI I I0OA Date April 2010 ECY 050-1-20 Met,06108)If-you need this document in an altenale format,please call the Water Resources Program at 360-407-6600. Persons with hearing loss can call 71l for Washington Relay Seri-ice. Persons+vith a speech disability can call 877-833-6341. APPENDIX C SLOPE STABILITY STABLE Slope Stability Analysis System New User Project Jo Galando Datafile: dynamic Bishop STABLE Version 9.03.00u Bishop ##+#+*4#4***************+***********444***44#++*4********* TITLE dynamic UNITS (Metric/Imperial) = I GEOMETRY DEFINITION POINTS NO. X Y 1 0.000 20.000 2 60.000 40.000 3 124.000 60.000 4 170.000 80.000 5 0.000 15.000 6 60.000 35.000 7 124.000 55.000 8 170.000 75.000 9 17.000 25.670 10 24.160 28.050 11 31.320 30.440 12 38.470 32.820 13 45.630 35.210 14 52.790 37.600 15 59.950 39.980 16 67.110 42.220 17 74.260 44.460 18 81.420 46.690 19 88.580 48.930 20 95.740 51.170 21 102.890 53.400 22 110.050 55.640 23 117.210 57.880 24 124.370 60.160 25 131.530 63.270 26 138.680 66.380 27 145.840 69.500 28 153.000 72.610 LINES Lo X Hi X SOIL 1 2 1 2 3 1 3 4 1 5 6 2 6 7 2 7 8 2 SOILS SOIL NAME LINETYPE-PEN COHESION FRICTION UNIT WT. STABLE02002 MZAssociates Ltd Printed on: 28/06/13 @ 15:55:50 Page: 1 TUBCW!Trpgf !TLbcjqu!Bobnot jt !Tzt Lf n Ofx !Vtfs QspIf dd!; Kp!Hbrboep Ebftrfi!; ezobn jd Cjt i pq Hsje!!!26!!!!Cjsdrrft!uispvhi !gpjou!!!!34 Hsje! !!27!!!!Elsdrrft!uispvhi !gpjou!!!!35 Hsje!!!28!!!!Ejsdrrft!uispvhi !gpjou!!!!36 Hsje!!!29!!!!11sdrrft!uispvhi !gpjou! !!!37 Hsje!!!2: !!!!Cjsdrrft!uispvhi !gpjou!!!!38 Hsje!!!31!! !!Ejsdrrft!uispvhi !gpjou!!!!39 ! ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ PCL U POf ! U OTJ PO!DSBCL!)Opof OEszOYf u*!! !!!>!O DSBDL!CBTFIZ!DPPSE!!!!!!t!!!!!!!!>!!!!! !1/111 ! FBSURJBLF!BDDFWSBW POI!!!1!!!! !>!!!!! !1/311 ! NJQJNMTMIEF!NBTT! ! !!!!1!!!!! !!!>!!!!! !1/111 ! ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ! OPJ OU!M3BEf I CPJCU!!!BCHKF!! !! !! !CPSDF ! ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ TPJM SFJOCPSDFNFCIJ !!!CPJCUB!!CPJCUC!!I!!G3SDF!!!CFO ! ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ TM1DF!EBUB>!O ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ !+!CJTI !npevrrf!.. !q t i pq!Trrj q!El sdnf!!Bobrrzt j t!+ !FISJE!!!!!!r!!!2 I+++++++++++++++ !Cjsdrrft!uispvhi !gpjou!!!)!!!!28/11!!!!36/78!* !TBGFUZ!GBDUPST ! !!! !!! !! !Y!!28/1!!43/2!!58/3!!73/4!!88/5! !:3/7!218/8!233/9!248/: !264/1 !!!!!Z !!327/1! !!! !!3/31!!3/19!. 1/12!. 1/12!. 1/12!. 1/12!. 1/12!. 1/12!.1/12!.1/12 !!319/9!!!!!!3/33!!3/21!.1/12!. 1/12!. 1/12!. 1/12!.1112!.1/12!.1/12!.1/12 !!312/8!!!!!!3/33!!3/24!. 1/12!. 1/12!. 1/12!. 1/12!. 1112!. 1/12!. 1/12!. 1112 !!2:5/6!!!!!!3/34!!3/25!.1/12!. 1/12!. 1/12!. 1/12!. 1112!. 1/12!.1/12!. 1112 !!298/5!!!!!!3/34!!3/26!.1/12!. 1/12!. 1/12!. 1/12!. 1/12!. 1/12!.1/12!. 1/12 !!291/3!! !!! !3/35!!3/28!!3117!. 1/12!. 1/12!. 1/12!. 1/12!. 1/12!.1/12!. 1/12 !!284/2!! !!!!3/31!!3/2: !!3/19!. 1/12!. 1/12!. 1/12!. 1/12!. 1/12!. 1/12!.1/12 !!276/: !! !!! !3/29!!3/31!13/22!. 1/12!. 1/12!. 1/12!. 1/12!. 1/12!. 1/12!. 1/12 !!269/8!!!!!!3/2: !!3/34! !3/24!. 1/12!. 1/12!. 1/12!. 1/12!. 1/12!. 1/12!. 1/12 TU3CW -3113!N[!BttpdjbLf Me Osjoufe!po; 390I7(24 A 26;66;61 Qbhf; M STABLE Slope Stability Analysis System New User Project : Jo Galando Datatile: dynamic Bishop 1 Soil—1 CONTINUOUS-BLACK 0.00 30.0 132.000 2 Soil—2 CONTINUOUS-BLUE 400.00 40.0 140.000 PORE PRESSURE SPECIFICATION SOIL PIEZO RU EXCESS Y/N/P Value Value 1 N 0.000 0.000 2 N 0.000 0.000 PIEZOMETRIC SURFACE POINT POINT PORE PRESSURES POINT PRESSURE SLIP DIRECTION (+/- X) SLIP-CIRCLES AUTOMATIC Circle Centre Grid Extremities 216.000 17.000 * * 153.000 + # 80.000 X spacing -- no. of cols (max 10)= 10 Y spacing -- no. of rows (max 20)= 20 Grid 1 Circles through point 9 Grid 2 Circles through point 10 Grid 3 Circles through point 11 Grid 4 Circles through point 12 Grid 5 Circles through point 13 Grid 6 Circles through point 14 Grid 7 Circles through point 15 Grid 8 Circles through point 16 Grid 9 Circles through point 17 Grid 10 Circles through point 18 Grid 11 Circles through point 19 Grid 12 Circles through point 20 Grid 13 Circles through point 21 Grid 14 Circles through point 22 STABLE62002WAssociates Ltd Printed on: 28/06/13 @ 15:55:50 Page: 2 TUBCNF!Trpgf !TLbcj*!Bobmt jt !Tzt Lf n Ofx !Vtfs Qspif dt!!; Kp!Hbrboep Ebibgfi!; ezobn jd Cjt i pq TU3CW!W st j po!:/14/11 v Cj t i pq ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ! W LAf ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ VOI LIT!)NfusjdOJngfsjbnf!!!!!! !!!!>!J ! FFPNFLISZ!EFGJ O1111 PO CPJ CUT ! !!CP/!!!!!! !!!Y!!!!!!! !!Z !!! !2!!! !! 1/1111! !131/111 ! !!!3!!!!71/Ill!!!!51/111 !!!!4!!!235/111!!!!71/111 ! !!!5!! !281/111!!!!91/111 !!!!6!! !!! 1/111!! !!26/111 !!! !7!!! !71/111!! !!46/111 !!!!8!!!235/111!!!!66/111 !!!!9!!!281/111!! !!86/111 ! !!!: 1!!!28/111!!!!36/781 !!!21!!!!35/271!!!!39/161 !!!22!!!!42/431!!!!41/551 !!!23!!!!49/581!!!!43/931 ! !!24!! !!56/741! !!!46/321 ! !!25!! !!63/8: 1! !!!48/711 ! !!26!!!!6:/:61! !!!4:/:91 !!!27!! !!78/221! !!!53/331 !!!28!!!!85/371! !!!55/571 ! !!29!!!!92/531!! !!57/7: 1 !!!2:!!! !99/691!!!!59/:41 !!!31!!!!:6/851!!!!62/281 !!!32!!!213/9: 1!!!!64/511 ! !!33!!!221/161! !!!66/751 ! !!34!!!228/321!!!!68/991 ! !!35!!!235/481! !!!71/271 ! !!36!! !242/641! !!!74/381 ! !!37!! !249/791! !!!77/491 !!!38!!!256/951!!!!7:/611 !!!39!!l264/111!!!!83/721 M1CFT ! !W!Y!!Ij !Y!!TPJM !!!!2!!! !!3!!!!!2 !!!!3!!!!!4!!!!!2 !!!!4!!!!!5!!!!!2 !!!!6!!!!!7!!!! !3 !!! !7!!!! !8!! !! !3 !!!!8!!!!!9!!!!!3 ! ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ TPJ MT ! TPJM!CBNF!!! !!!!!! !!! !NUCFLAZCF.CFC!1!! !! 1 !11 DPI FTJPCf !GSJDUJPOr!VOIUXIY TU3CW-3113!N[!Bttpdjbrft!Me O:gorfe!po; 390170?4 A 26;66;61 Qbhf; 112 MASON COUNTY DEPARTMENT OF COMMUNITY DEVELOPMENT Planning Division P O Box 279, Shelton, WA 98584 i (360)427-9670 Geotechnical ReportReview Acceptance Letter December 03, 2013 JOSEPH GALANDO 3124 SW 171 ST SEATTLE WA 98166 Case No.: GE02013-00030 Parcel No.: 322245000083 Proiect Description: Block wall built without permits or geo study review. The Geotechnical Report for JOSEPH GALANDO has been received and reviewed by the Planning Department. The report was prepared by Michael Staten dated 7/9/2013. Based on the certification provided by the licensed engineer/geologist, the referenced Geotechnical Report was prepared in general accordance with the requirements in the Mason County Resource Ordinance, Landslide Hazard Areas 17.01.100.E.5. Mason County considers the review valid until such time as scope of project, site conditions, and/or regulations change. Should the scope of work, site conditions, and/or regulations change after the original review, then an addendum from the original author of the report may be required to address these changes. The report would only be re-reviewed if a permit for development were submitted after these changes occur. Mason County does not certify the quality of the work done in this Geotechnical Report. Please contact me at (360) 427-9670, ext. 365 if you have questions. Sincerely, Allan Borden Land Use Planner Mason County Planning Department 7/M ��f Comments: RECEIVED CHECK ONLY. SENT EMAIL TO OWNER REMINDING HIM OF THE NEED FOR ACTUAL GEO REPORT. 07.15.13 TW 12/3/2013 Page 1 of 1 GE02013-00030