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GEOtechnical Report - GEO General - 3/15/2024
GEOTECHNICAL REPORT RESIDENTIAL DEVELOPMENT SITE 141 E JACK PINE LANE LOT 91 UNION, WASHINGTON PREPARED FOR ALDERBROOK PROPERTIES BY 36 cl ALL AMERICAN GEOTECHNICAL OLYMPIA, WASHINGTON MARCH 15, 2024 MASON COUNTY IQ' rharklict COMMUNITY SERVICES Geotechnical Report Bufld q Vlal .q.Fnvuormpntal Healln.(ommungy Healir. Instructions: This checklist must be submitted with a Geotechnical Report and completed, signed, and stamped by the licensed professional(s)who prepared the Geotechnical Report for review by Mason County pursuant to the Mason County Resource Ordinance. If an item is found not applicable, the report should explain the basis for the conclusion. Note: Unless specifically documented, this report does not provide compliance to the International Residential Code Sections R403.1.7 for foundations on or adjacent to slopes, Section R403.1.8 for expansive soils or section 1808.7.1 of the International Building Code Section for Foundations on or adjacent to slopes. Applicant/Owner Alderbrook Properties Parcel# 32104-50-0009/ Site Address 141 E Jack Pine Lane Union, Washington (1) (a) A discussion of general geologic conditions in the vicinity of the proposed development, Located on page(s) 6 - 7 (b) A discussion of specific soil types, Located on page(s) 7 - 9 (c) A discussion of ground water conditions, Located on page(s) 9 (d) A discussion of the upslope geomorphology, Located on page(s) 9 (e) A discussion of the location of upland waterbodies and wetlands, Located on page(s) 9 (f) A discussion of history of landslide activity in the vicinity, as available in the referenced maps and records. Located on page(s) 9 (2) A site plan which identifies the important development and geologic features. Located on Map(s) Figure 2 I (3) Locations and logs of exploratory holes or probes. i Located on Map(s) Figure 2 & page 9 (4) The area of the proposed development, the boundaries of the hazard, and associated buffers and setbacks shall be delineated (top, both sides, and toe)on a geologic map of the site. Located on Map(s) Figure 2 & page 10 (5) A minimum of one cross section at a scale which adequately depicts the subsurface profile, and which incorporates the details of proposed grade changes. Located on Map(s) Figure 2 & page 10 (6) A description and results of slope stability analyses performed for both static and seismic loading conditions. Analysis should examine worst case failures. The analysis should include the Simplified Bishop's Method of Circles.The minimum static safety factor is 1.5, the minimum seismic safety factor is 1.1, and the quasi-static analysis coefficients should be a value of 0.15. Located on page(s) 10 - 12 (7) (a) Appropriate restrictions on placement of drainage features, Rev. February 2018 Located on page(s 12 (b) Appropriate restrictions on placement of septic drain fields, s Located on page(s) 12 (c) Appropriate restrictions on placement of compacted fills and footings, Located on page(s) 12 - 13 (d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other slopes. Located on page(s) 13 (e) Recommended setbacks from the landslide hazard areas shoreline bluffs and the tops of other slopes. Located on page(s) 13 (8) Recommendations for the preparation of a detailed clearing and grading plan which specifically identifies vegetation to be removed, a schedule for vegetation removal and replanting, and the method of vegetation removal. Located on page(s) 13 - 14 (9) Recommendations for the preparation of a detailed temporary erosion control plan which identifies the specific mitigating measures to be implemented during construction to protect the slope from erosion, landslides and harmful construction methods. I Located on page(s) 14 - 15 (10) An analysis of both on-site and off-site impacts of the proposed development. Located on page(s) 14 -15 (11) Specifications of final development conditions such as, vegetative management, drainage, erosion control, and buffer widths. Located on page(s) 14 - 15 (12) Recommendations for the preparation of structural mitigation or details of other proposed mitigation. Located on page(s) 14 - 15 (13) A site map drawn to scale showing the property boundaries, scale, north arrow, and the location and nature of existing and proposed development on the site. Located on Map(s) 15 Curtis D Cushman hereby certify under penalty of perjury that I am a civil engineer licensed in the State of Washington with specialized knowledge of geotechnical/geological engineering or a geologist or engineering geologist licensed in the State of Washington with special knowledge of the local conditions. I also certify that the Geotechnical Report, dated March 15, 2024 and entitled 0 Residential Development Site 141 E Jack Pine Lane Union,Washington 1 meets all the requirements of the Mason County Resource Ordinance, Geologically Hazardous Areas Section, is complete and true, that the 6"V-j ceO �� assessment demonstrates conclusively that the risks posed by the 2439 Clandslide hazard can be mitigated through the included geotechnical -- Lurt ::: ���. • ;'UcE1rr, � design recommendations, and that all hazards are mitigated in such a (Signature and Stamp) manner as to prevent harm to property and public health and safety. Page 2 of 2 Disclaimer: Mason County does not certify the quality of the work done in this Geotechnical Report. ALL AMERICAN GEOTECHNICAL CONTACT INFORMATION PREPARER INFORMATION AAG PROJECT NUMBER: AAG24-021 CONTACT: CURTIS D.CUSHMAN I ADDRESS: 8947 BUTTONWOOD LANE NE OLYMPIA,WASHINGTON 98516 TELEPHONE: (360)491-5155 CELL/TEST: (360)481-6677 EMAIL ADDRESS: CURTIS.CUSHMAN@COMCAST.NET i CLIENT INFORMATION i I CLIENT: ALDERBROOK PROPERTIES CONTACT AMANDA MONTGOMERY TELEPHONE: (360)898-0055 BILLING ADDRESS: ALDERBROOK PROPERTIES 871 E BEACH DRIVE UNION,WA 98592-9769 SITE ADDRESS: 141 E JACK PINE LANE UNION,WASHINGTON EMAIL AMANDA@ALDERBROOKPROPERTIES.COM _ PARCEL NUMBER 32104-50-00091 � I GPS LOCATION: 47.334 -123.073 (dd) AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 2 j Phone#: (360)491-5155 Cell#:(360)481-6677 I A1.1. AMERIC'AN GEOTECHNIC ,X1. SCOPE OF UNDERSTANDING AnIAND.A MONTGOMERI ALDERBROOK PROPERTIES 871 EAST BEACH DRIVE UNION,WASHINGTON 98592-9769 RE: ALDERBROOK PROPERTY 141 E JACK PINE LANE UNION,WASHINGTON N47.334-123.073(DD) PARCEL 3 2 1 04-50-0009 1 MARCH 15,2024 Dear Amanda Montgomery: Amanda Montgomery (contact) for Alderbrook Properties (client) hired All American Geotechnical, Inc. (AAG) in January 2024 to do a geotechnical report for a residential property on a parcel in Mason County. Washington. The following is the report written to comply with the Mason County Requirements in the County Code -Critical Areas and in accordance with the Submittal ('hecklist For a Gentechnic•al Report for the above property in the Alderbrook Golf and Yacht Club development area south of Union in Mason County, Washington. References to "client" include information from the contact. The address. 141 E Jack Pine Lane, and the parcel number 32104-50-0091 consists of two lots. 91 and 92. but this report will address the conjoined lots as one parcel. The parcel is planned to be developed with a single-family residence. The geotechnical concern is of steep slopes along the southeastern property line. This slope well exceeds 40% slope and is over 35 feet in height. Landslide hazards will be noted and analyzed in text. This report will demonstrate the parcel is suitable in compliance with Factors of Safety for a Landslide Hazard Area. The location of the residence will require specific evaluation and engineering of the drainage if a standard dimensioned residence is to be built. As per client request, we did a relevant site visit and a search of public documents. Other geotechnical information is likewise included. We appreciate this opportunity to be of service to you and we look forward to working with you in the future. If you have any questions concerning the above items, the procedures used. or if we can be of any further assistance, please call us at the phone number listed below. o o{ 4 a_s��?/ Respectfully Submitted. ALL AMERICAN GEOTECHNICAL,INC. �\ Fngineennq Geolc jisl y �O 2'"g i -..._._/,0 Curtis D. Cushman, L.G., L.E.G. :d(;ems Senior Engineering Geologist Curtis Dt-ar.. Ct1shI17a,J AAG24-021 8947 Buttonwood Lane NE.Olympia. WA 98516 3 Phone#: (360)491-5155 Cell #: (360)481-6677 ALL AMERICAN GEOTECHNICAL TABLE OF CONTENTS SCOPE OF UNDERSTANDING 3 INTRODUCTION 5 1) SITE CONDITIONS 6 SURFACE CONDITIONS 6 A) SITE GEOLOGY 6 B) SOIL 7 C) GROUND WATER CONDITIONS 9 ' D) UPSLOPE GEOMORPHOLOGY 9 E) UPSLOPE WATERBODIES AND WETLANDS 9 F) LANDSLIDE ACTIVITY 9 2) SITE PLAN 10 3) EXPLORATORY HOLES OR PROBES 10 4) PROPOSED DEVELOPMENT 10 5) CROSS SECTION 10 6) SLOPE STABILTY ANALYSIS 10 SEISMIC LIQUEFACTION HAZARD I 1 GEOSEISMIC SETTING 11 LATERAL EARTH PRESSURES 12 CONCLUSIONS AND RECOMMENDATIONS 15 PROVISIONS 16 READ THESE PROVISIONS CLOSELY 16 REFERENCES 17 APPENDIX 19 WELL LOG—ALDERBROOK INN 20 LIDAR IMAGERY 21 ASCE7-16 DESIGN SPECIFICATIONS 22 SLOPE MODELS 24 -STATIC MODEL A-A' 24 DYNAMIC MODEL A-A' 25 FIGURE 1 VICINITY MAP 26 FIGURE 2. SITE PLAN 27 FIGURE 3. EROSION CONTROL NOTES 28 AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 4 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL INTRODUCTION This report summarizes the results of our geotechnical study of the parcel herein described. The parcel is . 0.69 acres in area and is a rectangle somewhat long to the northwest-southeast. The parcel is currently undeveloped. Access from Union Washington and SR-106 is via E Beach Drive to E Country Club to E Manzanita Drive, then to E Jake Pine Lane. In general,the parcel slopes down from northwest to southeast with a broad low rise of up to just under 10 feet in the western two-thirds before the sharp descent to the east. This latter slope exceeds 40%for over ten feet in height and calls for a geotechnical report. The parcel is located on typical glacial scour-and ridge-and-valley terrain,with the golf-course in the valley scour or in a dendritic drainage,the residence on the ridge. The development area is forested in juvenile conifers, other trees, and lower story underbrush. Elevations range from a high of around 505 feet in the center of the parcel to approximately 480 feet in elevation at along the southeastern property line although the slope continues to drop another 20 feet off parcel to the southeast. The proposed development is located around the 490-foot contour. Our understanding of the project is based on information from the contact. The site and development has been drawn on Figure 2 of this report on the base of the Mason County GIS and the Alderbrook map. This geotechnical report and the checklist for Mason County involves the following: 1. A review of the available geologic,hydrogeological and geotechnical data for the site area. 2. A geologic reconnaissance of the site area and surrounding vicinity. 3. Investigation and identification of shallow subsurface conditions at the site by characterizing the exposed soil, sampling, and reviewing published well logs. 4. Comparison of the site to published geologic maps, previous field investigations,and open file reports. Inspection of aerial photographs to determine the geomorphology of the site. 5. Evaluation of the landslide, erosion, and seismic hazards at the site per the Mason County Critical Areas Ordinance regulations. 6. Slope modelling. The slope descending from the parcel to the southeast exceeds 40% and is greater in height than 10 feet. This is considered a Landslide Hazard Areas(LHA)Therefore,Mason County requires that a geotechnical report be prepared in accordance with the Mason County Code of Ordinances; &52 Resource Ordinance. 8.52.140 Geologically hazardous areas. AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 5 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL 1) SITE CONDITIONS SURFACE CONDITIONS The proposed location for the residential development is part of an extensive scour-and-ridge glacial plain cut by numerous drainages. This extends south of Union,Washington. The terrain in this area is relatively flat with steeper slopes lining the drainages. The drainage to the southeast was developed to accommodate a golf fairway. Curtis D Cushman L.E.G. and Blaise Jelinek E.I.T. of AAG conducted a site reconnaissance on February 13,2024. The purpose of a site visit is to physically observe the property and adjacent properties in order to identify any recognized geologic conditions. Visual observations were documented. There are no saturated soils on the property. There is no evidence of erosion on site. There was no standing water seen at the time of the site visit. The property overall is basically covered with juvenile trees and understory vegetation. The trees are generally straight and vertical showing little or no signs of slope movement. A) SITE GEOLOGY The site is mapped as Qgt—Fashon Stade till and on the Mason County GIS is described as: Geologic Unit Label: Qgt Geologic Age: Pleistocene Lithology: continental glacial till, Fraser-age Named Units: mostly Vashon Stade in western WA; unnamed in eastern WA Symbology: Pleistocene continental glacial till This is in keeping with the mapping of the Geologic Map of the Shelton 1:100,000 Quadrangle, Washington by Logan,R. L. 2003; Open File Report 2003-15. The Vashon till generally is relatively thin and in this area it is mapped as overlying a layer of Qga: Geologic Unit Symbol:Qga Geologic Unit Age: Pleistocene Geologic Unit Name: Vashon Stade advance outwash Associated Unit: Qga? Publication Source: WGS Publication Number: OFR 2010-3 Quadrangle Name: Union Unit Description:Pebbles, cobbles, sand, and beds and lenses of silt and clay;gray to tan; clasts typically well rounded and well sorted;clean (percendt[sic];S percent silt or clay in matrix), except in less-sorted and more angular ice proximal deposits;generally compact..., but commonly cohesionless; AAG24-021 8947 Buttonwood Lane NE, Olympia,WA 98516 6 1 f Phone#: (360)491-5155 Cell#:(360)481-6677 r ALL AMERICAN GEOTECHNICAL very thinly to very thickly bedded; contains planar and graded beds, cut-and-fill structures, trough and ripple crossbeds, and foresets; thickness typically between 100 and 300 ft... The area overall appears to be substantially till or till-like diamicton deposits. The Vashon till is widespread in the area and constitutes a commonly used base for residential construction and is acceptable for infiltration depending on septic design. It overlies the glacially compacted outwash deposits. The deposits seen on site are likely SP Poorly graded gravelly sand with silt using the ASTM classification. These glacial deposits are firm and suitable for construction. The water well drilled for the Alderbrook Inn but located as being on Jack Pine Star Lane shows a very mixed lithology as might be expected in glacial till,advance outwash,and other drift elements. Some water was encountered below -38 feet but this indicates that there should be no water phreatic encountered on the client parcel. (See Well Log—Alderbrook Inn in the Appendix,page 20) There are no nearby geologic faults or folds of consequence. The closest fault of note is the Tacoma fault zone that is to the northeast near Allyn, Washington. Seismic acceleration is important in modelling the slope stability as the Puget Sound area is in an active tectonic zone and although this fault does not pose an immediate hazard to the proposed building project, low levels of seismic activity are not uncommon and there is always the possibility of a major shock. In the case of a Cascadia event,the site is mapped on the Mason County GIS as in a zone with a potential MMI of 8 -Severe. B) SOIL The soil at the upper part of the parcel is described by the USDA Web Soil Survey as: Ab—Alderwood gravelly sandy loam,8 to 15 percent slopes Map Unit Setting • National map unit symbol: 2t626 • Elevation: 50 to 800 feet • Mean annual precipitation: 20 to 60 inches • Mean annual air temperature:46 to 52 degrees F • Frost free period: 160 to 240 days Map Unit Composition • Alderwood and similar soils: 85 percent • Minor components: 15 percent • Description of Alderwood Setting • Landform: Ridges, hills • Landform position (two-dimensional): Shoulder AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 7 Phone#: (360)491-5155 Cell#:(360)481-6677 : ALL AMERICAN GEOTECHNICAL • Landform position (three-dimensional): Nose slope,talf . Down-slope shape: Linear, convex • Across-slope shape: Convex s • Parent material: Glacial drift and/or glacial outwash over dense glaciomarine deposits Typical profile . A - 0 to 7 inches: gravelly sandy loam . Bwl - 7 to 21 inches: very gravelly sandy loam Bw2-21 to 30 inches: very gravelly sandy loam . Bg-30 to 35 inches: very gravelly sandy loam . 2Cd1 -35 to 43 inches: very gravelly sandy loam • 2Cd2-43 to 59 inches: very gravelly sandy loam . Properties and qualities • Slope: 8 to 15 percent • Depth to restrictive feature: 20 to 39 inches to densic material • Drainage class: Moderately well drained • Capacity of the most limiting layer to transmit water(Ksat): Very low to moderately low(0.00 to 0.06 in/hr) . Depth to water table:About 18 to 37 inches . Frequency of flooding:None • Frequency of ponding:None • Available water supply, 0 to 60 inches: Very low(about 2.7 inches) This is likely the soil underlying the proposed development. The eastern part of the parcel is as follows: Ac—Alderwood gravelly sandy loam, 15 to 30 percent slopes Map Unit Setting • National map unit symbol: 2t627 • Elevation: 0 to 1,000 feet • Mean annual precipitation: 25 to 60 inches • Mean annual air temperature:46 to 52 degrees F • Frost free period: 160 to 240 days Map Unit Composition • Alderwood and similar soils: 85 percent • Minor components: 15 percent Description of Alderwood Setting • Landform: Hills, ridges • Landform position (two-dimensional): Backslope • Landform position (three-dimensional): Nose slope, side slope,talf AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 8 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL • Down-slope shape: Convex, linear • Across-slope shape: Convex • Parent material: Glacial drift and/or glacial outwash over dense glaciomarine deposits Typical profile • A - 0 to 7 inches: gravelly sandy loam • Bwl - 7 to 21 inches: very gravelly sandy loam . Bw2-21 to 30 inches: very gravelly sandy loam Bg- 30 to 35 inches: very gravelly sandy loam • 2Cd1 -35 to 43 inches: very gravelly sandy loam • 2Cd2 -43 to 59 inches: very gravelly sandy loam Properties and qualities • Slope: 15 to 30 percent • Depth to restrictive feature: 20 to 39 inches to densic material • Drainage class:Moderately well drained • Capacity of the most limiting layer to transmit water(Ksat): Very low to moderately low(0.00 to 0.06 in/hr) • Depth to water table:About 18 to 37 inches • Frequency offlooding:None • Frequency of ponding:None • Available water supply, 0 to 60 inches: Very low(about 2.7 inches This gravelly sandy loam is seen in surface cuts which then becomes indistinguishable from the underlying till deposits. Note that the soils are"moderately well drained." C) GROUNDWATER CONDITIONS There was no standing water at the time of the site visit. There were no springs or seeps seen on-slope. There was no evidence of active surface erosion. D) UPSLOPE GEOMORPHOLOGY There are no appreciable upland heights near the parcel. E) UPSLOPE WATERBODIES AND WETLANDS There are none. F) LANDSLIDE ACTIVITY There are no landslides mapped in the area, and LiDAR shows the terrain to be low and eroded with no evidence of mass-wasting on or near the client parcel. There was no evidence of current on-site landslide activity. (See LiDAR Imagery on Page 21 in the Appendix.) AAG24-021 8947 Buttonwood Lane NE, Olympia,WA 98516 9 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL 2) SITE PLAN Please see Figure 2 in the Appendix. 3) EXPLORATORY HOLES OR PROBES The site was surface examined along the access roads and in exposures on the property, and on the bluff where parts of the column are visible. See Figure 2. 4) PROPOSED DEVELOPMENT This will be a single-family residence with associated septic and access. 5) CROSS SECTION Two cross-sections are in the Appendix. They are along line A-A'. 6) SLOPE STABILTY ANALYSIS The Slope Stability Analysis is as follows following the Mason County Code of Ordinances of 2021: 8.52.140 (E)(5) (d) A description and results of slope stability analyses performed for both static and seismic loading conditions. Analysis should examine worst case failures. The analysis should include the Simplified Bishop's Method of Circles. The minimum static safety factor is 1.5, the minimum seismic safety factor is 1.1 and the quasi-static analysis coefficients should be a value of 0.15. Slope stability was modeled using the GALENA 6.1 program in both static and dynamic conditions (ca= 0.15). "Static" condition refers to an "as is" state of a given slope. "Dynamic" puts seismic acceleration into the model for earthquake conditions. The factor for ground acceleration (ca)was determined from the Peak Ground Acceleration from the USGS Seismic Design Maps, included in the Appendix. The surface soil was field classified as a SP, a Poorly graded gravelly sand with silt. These units are consistent with the description of the Qgt Vashon till. The site was modeled in two layers, with the Qgt overlying the Qga. Parameters used for the subsurface material are presented in the table below. Table 1. Modeling Parameters for Subsurface Material Geologic Unit Unit Weight Cohesion Phi Angle Qgt -Vashon Stade till 11�; 200 32 Qga- Vashon Advance Out-,vash 118 300 34 AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 10 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL Factors of safety were determined using the Bishop (semi-circular) method. Under static conditions, the slopes did not show susceptibility to deep-seated failure that would cause damage to the septic or residence. See Appendix for model output and cross-sections. Under dynamic loading(Ca=0.15),the computations demonstrated that the site has a high FoS with respect to the slopes. The following are the Factors of Safety (FoS)attained for the sections with respect to their current topographical representation. I General information for the slope profiles and the initial positions for analysis is presented in the following table. Table 2. Initial Positions, Variance, and Findings Anah sis Load Across Analysis Earthquake Slope to Initial Positions(Auah-sis Range) C anflguratious Factor of Number Building Favelope Type Force Building Loner L pper RadiusAuah-zed Safeh" Cross-Section A A' ................ ................ ........._.......,_.__.................................._..._..._. __.. .......... -- ..................................... _..... 91-'�1' Static 0 0 g Below 145(50) 218(54) 100(30) 125 001 1.83 Aiial is 1 1,.00 1 t t............................,. ........ Analysis 2_ 1�,004 191-244' Dinannc: 0.1- g : Below ? 145(50) 218(54) 100(30) 1�5 001 1.51 The values input were selected to be as conservative as possible so the FoS are possibly higher. The graphic output of these data is presented in the Appendix, pages 24-25. SEISMIC LIQUEFACTION HAZARD The Liquefaction Susceptibility Map of Mason County, Washington by Palmer, Magsino, Poelstra, Bilderback, Folger, and Niggemann (September 2004) maps the site area as having a Very Low liquefaction potential. The Site Class Map of Mason County, Washington by Palmer, Magsino, Bilderback, Poelstra, Folger, and Niggemann(September 2004)maps the area as site Class C. Site class C is a very stiff soil or soft rock. GEOSEISMIC SETTING According to the Seismic Zone Map of the United States (Figure 1613.3.1(1)) contained in the 2015 International Building Code (IBC), the project site is located where the maximum spectral response acceleration is greater than 65 percent of gravity (g). We recommend following seismic factors for design purposes. • Site Class: C (stiff soil/soft rock) • Spectral response acceleration, short period(SMs): 1.870g(Fa= 1.2) • Spectral response acceleration, 1-second period(SM1): 0.823g (F,,= 1.421) • Peak Ground Acceleration 0.669 AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 11 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL LATERAL EARTH PRESSURES Lateral loads may be resisted by friction on the bases of footings and floor slabs and as passive pressure on the sides of footings. An allowable coefficient of friction of 0.40 may be used to calculate friction between the concrete and the underlying native soil. We recommend the following be used to determine the lateral earth pressures considering the onsite SP: • 0 (soil friction angle) 32 degrees • Ko (at rest earth pressure coefficient) 0.470 • Ka(active earth pressure coefficient) 0.307 • Kp (passive earth pressure coefficient) 3.25 • y(soil unit weight) 115 pcf 7) RESTRICTIONS A) PLACEMENT OF DRAINAGE FEATURES Drainage may be done by surface dispersion. The possible alternative is a Capture-Transport-Dispersal (CDT)system taking storm water from a collection basin for the residence via tightline to a dispersion head where the water is dispersed to avoid erosion. This is not likely as there has to be somewhere to send the water and it cannot be drained on steep slopes. All ground surfaces,pavements and sidewalks should be sloped away from the proposed residence and any associated structures. Surface water runoff should be controlled by a system of curbs, berms, drainage swales, and/or catch basins and disposed of properly. We recommend that conventional roof drains be installed. Footing drains shall be installed for the proposed structure. The roof drain should not be connected to the footing drain. For footing drains, the drain invert should be below the bottom of the footing. Typical drainage control measures are included on Figure 3 in the Appendix. The soil will accept downspout and other drainage located at least 5 feet from the edge of the footing of the residence. (Figure 3 shows recommendations for a tightline system that is not applicable to this parcel.) Again, drainage should be such that there is no flow onto steep slopes. As you want gravity to propel the drainage system, it is possible a modified CTD system may be employed to drain water to the north. The low ridge would have to be factored into the design. A pump system is not recommended. B) PLACEMENT OF SEPTIC DRAIN FIELDS The drain field is located as mapped on Figure 2. The drainfields will be outside the LHA and the 50-foot vegetation buffer. These are not intruding on the LHA and are thus on slopes below 40%. Water is community sourced. C) PLACEMENT OF COMPACTED FILLS AND FOOTINGS RECOMMENDATIONS FOR SITE PREPARATION AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 12 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL Vegetation will be removed as needed to develop the site. Nothing will be done in the LHA on-parcel. Trees will be felled as needed for the septic drainfields and the residence. All areas to be excavated should then be cleared of deleterious matter including any debris, duff, and vegetation. All deleterious material will be removed and sub-soils reached for developing the property. Any material that is excavated may be stockpiled and later used for erosion control and/or landscaping. Surficial material unsuitable for these tasks should be removed from the project site. No foundation elements shall be constructed on"untested"fill material. If demonstrated to be acceptable,the sand/gravel sedimentary material on site may be suitable for re-use as structural fill. Where placement of fill material is required, the exposed subgrade areas should be compacted to a firm and unyielding surface prior to placement of any fill. Over-excavation in any building area should be backfilled with structural fill, compacted to the density requirements described in the "Structural Fill" section,below. RECOMMENDATIONS FOR STRUCTURAL FILL All fill material should be placed as structural fill. In general, the structural fill should be placed in horizontal lifts of 8 inches to allow adequate and uniform compaction of each lift. Fill should be compacted to at least 95 percent of MDD(maximum dry density as determined in accordance with ASTM D-1557)to grade. The final appropriate lift thickness will depend on the fill characteristics and compaction equipment used. Material placed for structural fill should be free of debris, organic matter,trash, and cobbles greater than 6 inches in diameter. The moisture content of the fill material should be adjusted as necessary for proper compaction. Onsite soils may be considered for use as structural fill only if industry standards are satisfied. Fill material requirements are found on page 9-26 to 9-30 of the WSDOT Standard Specifications 2010. In general, a native soil (sand, silt, and gravel) encountered on a site must have less than 10 percent fines (material passing the US No. 200 sieve)to be suitable for use as structural fill D) BUFFERS The construction area is inside the 50-foot vegetation buffer while the septic drainfields are outside of it. The development may continue if adequate erosion control is observed as there is limited space on this parcel. The slopes are such that erosion should be considered as a factor but, with proper control, not a limiting factor. The LHAs shall not be disturbed. E) SETBACKS The drainfields are plotted on Figure 2. Setbacks are as noted. AAG24-021 8947 Buttonwood Lane NE,Olympia, WA 98516 13 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL 8) CLEARING AND GRADING PLAN The building footprint for possible construction is inside the 50-foot vegetation buffer. Timber clearing will be needed. This will be limited to development around the septic drainfields and the residence. No major grading is anticipated. "No Disturb" zones will not be required. No formal plan should be needed as long as safe procedures are employed with the clearing in keeping with Mason County regulations. Hazard trees may be removed if needed. See"Erosion Control Plan,"below. All job site safety issues and precautions are the responsibility of the contractor providing services and/or work. 9) EROSION CONTROL PLAN It is our opinion that the potential erosion hazard of the site is not a limiting factor for the proposed developments. Removal of vegetation will be limited to the development sites and where removed, it is to be revegetated. Simple erosion control methods will reduce or eliminate any potential erosion risk. Trees and understory growth on the LHA slope itself will not be disturbed. Revegetation as needed should occur immediately following disturbance of the soil. No hazard trees appear to be present. The possibility of down-slope contamination is unlikely if proper control methods are employed. A silt fence may be installed as shown on Figure 2 as other control methods, such as swales and baled straw are likely not practical for the residence due to proximity to the LHA . No re-contouring of the site will occur. Surface drainage should be directed away from all slope faces. Straw, hay, or jute matting shall be used to cover the exposed soils until permanent vegetation is established. All slopes should be seeded as soon as practical to facilitate the development of a vegetative cover, or otherwise protected. Surface water should not flow toward or over any steep slopes. Drainage pipes should not daylight on any steep slopes. A revegetation plan should not be required. When residential plantings or any plantings on the periphery of the residential area and the slopes are planned, native species should be considered as the primary vegetation in areas away from lawn and ornamental plantings. Shallow rooted species, such as grass, should be planted closer than 10 feet from underground drainages. Densely rooted evergreen shrubs are preferable than tree species on slopes greater than 15%gradient. Tall trees may become unstable in wet soils under high wind conditions. In general, the steep sides of the bluff should be left in a natural condition unless erosion or sloughing eventually pose a hazard to the residence. 10) ON AND OFFSITE IMPACTS There should be no notable on- or offsite impacts if the project is completed according to the recommendations of this report and in accordance with all regulations and to the high standards and practices of the building contractor. AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 14 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL 11) FINAL DEVELOPMENT CONDITIONS All final conditions will follow the design by the Engineer of Record and compliance with all regulatory agencies. If this and the above recommendations are followed, final development conditions may be achieved. 12) STRUCTURAL MITIGATION There is no structural remediation to be done. 13) SITE PLAN Please see Figure 2. CONCLUSIONS AND RECOMMENDATIONS Based on the results of the site reconnaissance, subsurface observations, and our experience in the area, it is our opinion that the proposed development site on the client property is suitable for a residential development. The residence and septic drainfields may be located as shown on Figure 2 in this report. The erosion hazard is manageable, and drainage should not pose a great problem. The parcel is limited in buildable area, so the 50-foot vegetation buffer may be built in as long as adequate erosion control is provided during and following construction. The project of development should proceed. AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 15 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL PROVISIONS GENERAL We have prepared this report for the exclusive use of Alderbrook Properties and their authorized agents for development of the property in Mason County, Washington. Site inspections,research,and mapping have culminated in this report. This report is intended to meet the requirements of the Mason County Code. This report does not specify setbacks for: line-of-sight setbacks, FWHCA setbacks, eagle tree setbacks, wetland setbacks, or property line setbacks. Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices in the field of geotechnical engineering in this area at the time this report was prepared. No warranty or other conditions, expressed or implied, should be understood. Clients and property owners must understand that,while a slope may be found to have an acceptable Factor of Safety related to deep-seated mass wasting, surficial failure and landslides can and do occur on steep slopes. The property owners should monitor the stability of their property. Moreover, acceptable Factors of Safety do not guarantee there cannot be failures. It is the responsibility of the property owners to understand that there are always risks in building on or near steeply sloped areas. CONTRACTORS ARE RESPONSIBLE FOR SITE SAFETY ON THEIR OWN CONSTRUCTION PROJECTS Our geotechnical recommendations are not intended to direct the contractor's procedures, methods, schedule or management of the work site. The contractor is solely responsible for job site safety and for managing construction operations to minimize risks to onsite personnel and to adjacent properties. READ THESE PROVISIONS CLOSELY Some clients, design professionals, and contractors may not recognize that the geoscience practices (geotechnical engineering or geology) are far less exact than other engineering and natural science disciplines. This lack of understanding can create unrealistic expectations that could lead to disappointments,claims and disputes.All American Geotechnical includes these explanatory"limitations" provisions in our reports to help reduce such risks. i AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 16 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL REFERENCES MAPS DeLorme 3-D TopoQuads(2002),Source Data USGS,Yarmouth,Maine. Dragovich,Logan,Walsh,and Schasse(2002),Geological Map of Washington—Northwest Quadrant(Geological Map GM- 50),published by Washington State Department of Natural Resources. Logan,R.L.,(2003);Geologic Map of the Shelton 100,000 Quadrangle, Washington;DNR Open File Report 2003-15. Palmer, Magsino, Poelstra, Bilderback, Folger, and Niggemann (September 2004), The Liquefaction Susceptibility Map of Mason County, Washington,published by Washington State Department of Natural Resources. Palmer, Magsino, Bilderback, Poelstra, Folger, and Niggemann (September 2004), The Site Class Map of Mason County, Washington,published by Washington State Department of Natural Resources. Polenz,Michael and others(2010);Geologic Map of the Skokomish Valley and Union 7.5-minute Quadrangles, Mason County, Washington;DNR OFR-2010-3. Rogers,A.M.,Walsh,T.J.,Kockelman,W.J.,and Priest,G.R.(1996),Map showing known or suspected faults with quaternary displacement in the Pack Northwest,published by U.S.Geological Survey,OFR 91-441-0,Plate 1,scale 1:2,000,000. PUBLICATIONS ASTM International(2005).Annual Book of Standards 2015, Section 4, Volume 4.08,published by ASTM International,West Conshohocken,Pennsylvania. Kollmorgen Instruments Corporation(1994),Munsell Soil Color Charts(1994 Revised Edition),published by Macbeth Division of Kollmorgen Instruments Corporation,New Windsor,New York. Ness,Fowler,Parvin(1960),The Soil Survey of Mason County, Washington, USDA Soil Conservation Service,in cooperation with the United States Department of Agriculture, and Washington Agricultural Experimental Station, and the Soils Conservation Service. Parks, Neal, Koloski, Laprade, Molinari, Butler, and Lorentson (November 2006), Guidelines for Preparing Engineering Geology Reports in Washington, published by Washington State Geologist Licensing Board,Olympia,Washington. WEBSITES(ALSO ON MASON COUNTY GIS,WASHINGTON GEOLOGIC PORTAL,AND USDA WEB SOIL SURVEY) Mason County Government Information Services (http://www.co.mason.wa.us) Mason County Codes,Ordinances,and Regulations (http://www.co.mason.wa.us/code) Puget Sound Lidar Consortium (http://pugetsoundlidar.ess.washington.edu/lidardata/index.html) Slope Stabilization Erosion Control Using Vegetation A Manual of Practice for Coastal Bluff (http://www.ecy.wa.gov/biblio/9330.html) AAG24-021 8947 Buttonwood Lane NE,Olympia, WA 98516 17 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL Vegetation Management Guide for Puget Sound Bluff Property Owners (http://www.ecy.wa.gov/biblio/9331.html) United States Department of Agriculture Natural Resource Conservation Service (http://soildatamart.nres.usda.gov) Washington Administrative Code (http://apps.leg.wa.gov/wac/) Washington Department of Ecology (http://apps.ecy.wa.gov/welllog) (https://fortress.wa.gov/ecy/coastalatlas/viewer.htm) AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 18 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL APPENDIX Well Log—Alderbrook Inn LiDAR Imagery USGS Seismic Design Specifications Slope Models Figure 1. Vicinity Map Figure 2. Site Plan Figure 3.Erosion Control Notes. AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 19 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL WELL LOG—ALDERBROOK INN yj ill.Orltltt.i and rlrst CePy elth •1 j Application No tn.th�u.m"Ice w.ler la.�.rm•,t WATER WELL REPORT i� Second.'a+ OwnerY Copy 7T+]rei.Cvyy�Dt2liat'/Copy L0I0_57_0_-6-L STATC OF 1CASuMOTON Permit xo..... T _ Q' (1).OWNER: Name A7/e4PRiwee�..__04/fyr"f_.........I Address UJ1iGIli �L d (2) LOCATION OF WELL: eaunty-........ ._./�'a.s_P!�- - 1: 1.see T_;-2./N..R2.", .N. Bt and dlstaaT from aectton or lulodiv)sion corner N (3) PROPOSED USE: Domt.ue Cl )ndurtnal p MUnl.ipal L) (10) WELL LOG: _ Irrigatlonx Tesi well ❑ Other O /'ormulWn DtK,tW by eole,,eAdrati�er/pre v!+ae1/,4t1 and arrycture,and ihetc IA+ckalsl cJ equ"A Dad fhe klna awd'�6tYrJ at tM mattr.a2 4\tech at,atun lvaetrated. W th at!fast one entrV for each rnaage of fo,ntatisn. O (4) TYPE OF WORK: uwr.er,number],I well - ---_- -- tit m than one] MATI[RIAL r'ROX " TO C New well Method:Dug 0 Bored Q p Deepened El cable Ix Driven Q r�� ---- --- -- RReconditioned O Rotary U Jolted (] S) DIMENSIONS: rr NS: lhaeter of well_. iadt$L t0 Drilled.(Gf7O. ft Depth of completed d (S) CONSTRUCTION DETAILS: � Casing installed:/0 - m.m tram 0 ft to30 % ft 4nd�t�j�,{�U. _. Threaded C d.._,`Dia from © papa ft,to 60 G. tt. _.!!may -d m p welde!% ..__-Dt.m from .. .. n.to _ n l/Pd V C Perforations: Yp No r 3 `3Yt,/lj k r,�� k,f .2 1 - �n -� Type o[perforator used �t TJ��/ ?/J,.�� � (��(,j-• �/t /r Q ++/5ry p St7- pf perio+at ons 3�i' by " _J !9've =C'-,/P y i 0�.._ prtontlons frum 1 It to p. R _ r.�� ,�4R 0 9 Perforations from J e Q ft.to.3 f7 7 ft. �-t perforations frum..i-2-9 .It to r3.3. ,. R. Q r1&&0,��'i2YCL�aj Screens: ref CJ no Pne S& 10.1 Manufacturer's Nano ago"No...__.___._,_....... - v v ` D:am. No.laa____.._dotn_....._..._. ft.to_..-_..__u. . 41_ .f!,!!y _ 13-Q�,'�.5�12_ Dtam. NM Mae, ..r_item- __ .tt to........__R 4rkeMfi Q C6(6 14 P Pchru I-0Y1 RYffi. SIv_.. 6Q. Gravel packed: YmQ moo prr[Ls� Y6L. Gravri placed from.._ _...n.to..- papa n RH &A o _. _ G , -r&jyD ! C�Ax- —� �z 3Bo_ Z Surface seal: Yesy ft To wn.t neplk+ .ao..... n. r/LgX/LX?1�dBl�L_.(�8y ( �ryy 1/F�z Vf Mater:ai used in ual... !H Isr rl//Z_._.._..._ _.._. -(,j`[.�J/�t.L t�Q_— .QJ_--..Tr•/_ z Old any strala contain unusable water? Yea Q Noe j�r/QY f.• �i n VV Type of water/ Drrth of strata..-__...__._ _Y vCIL blethad of.eating strata off O (7) PUMP: Manufactunia Name CrellcEltFD_rrdRYIIL1SCC!{�1]1r8 Type:__..__._._papa..-.-._.......______...--. ar.... ..._... __-- /5�61;�P.9ly •�. �_ cpi L3 owft- CLAY 4IfD W ($) WATER LEVELS: Land-wrfaee elevatian �,-• aMw meen ace trvel....X L ft _ R12-eR.IY.�_ .5'Z - 0 static level -077 ..._._art.b.lovr top at wall Date9/ICI 1Q.! �sJ��� 2 sj �4'.« Arlrs:ah pressure -Abs.Per sOture loch Dale. .. - L/_,.,.,, 0 -j% - C Artesian water is controlled by....-_.__..__.___......_papa_..._.._ _. /�LLI7K-as-C r 4! iGp,wive etc.! C-K'!Yfe.L Y ►�xBr i.11tL (9) WELL TESTS' Drawdown is amount castor level Is y � G/l/IYC�s p QQG ' lowered below stauc Intl .d;ark darted ../ AIL..._._,1t�7- e:ooWded._.../�Z5__._.•lt�►/ MWas a pump test model Yer No O It yes-by whom•.UriZs��Cti 12Yiela D gala/mm,w(i 'h SSA�t dra.doern After nr: WEI.I, DRILLEWS STATEMENT: C This W 11 was drilled under my Jurisdiction and this report is true to the best or my knowledge and belief. t Reenvary data ttlme taken Y Sore when pump lttrnod off) (water level +nwsutM trash well top to water!even '�,t, Ttnr water Levee Tim. Wate, Lr..I ( Tlme Were,Level NATAIR T)/Z'!e Wa.L.4o..... . or rporation) ITYPO or tl .................__..._._.._...... ............................_......._..............._................... _ �yn_L . ... _ __._ - ._._ __....._...... ... Add re�..I ..Prm s wI7L(' . papa........................... J� papa. .. ......._..._........._.,..... e. Date of tell_...`�JatZ.l_6'. _ (Sfgr:edJ. .. ......_.._..... Daher test................jailm4t.wtib___.___.1t,dratedawp after.. hn Asa Dri0erl Artryfan ffdw .__-._._.,__jsart. Date Temreratur.of water. ..Was a chemical snalysi.msdo't Yes C No Ucvnse No Date 19. j (USH ADDITIONAL SHC}TS it NECESSARY? B.P.No.TSS6-OS-.Rry :•(gyp)--S-6r �a e7 AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 20 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL UDAR IMAGERY Mk- 5• P 1 IIII � t! x f 0000000 , e 8 8 AAG24-021 8947 Buttonwood Lane NE,Olympia, WA 98516 21 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECI-INICAL ASCE7-16 DESIGN SPECIFICATIONS ATCHazards by Location Search Information v Seattle 014 "`1rj a Coordinates: 47.334 23 073 496ft frr� urtrm R�r:or' Elevation: 496 ft r l)-tstlt. rnTn:•.' v Timestamp: 2024-53-15T01:07:43.275Z ! Tacoma Hazard Type: Seismic C Beac-'=- Slrl,.ar o. Put n IMP -3kewood, Reference Document ASCE7-18 is f'ra•.l ; -dpnl1:n Risk Category: 111 "% � le 1,120 >Aterdecn data c2 Px 0 :Goa;te pon s rnea enoi Site Class: C WER Horizontal Response Spectrum Design Horizontal Response Spectrum Salgl Saigl t.M 1 50 1.00 I 0;0 I 1 00 0.60 050 0.40 0.<0 0.00 0.00 0 5 = 15 Period Is) CI 5 110 15 Period Is) Basic Parameters Name Value Description SS 1 M19 MCEa ground motion:penac=0.2s; S1 0.579 MCER ground motion{period=IA s skj1 1 87 S4e-nodi`ed soectal acceeraoon value SM1 0.823 Sle-modi`ed soecml aoce-*ration value sx� 1 2 47 Nume-,seismc des:g-va-�e at C.2s SA so- 0 542 Numerc seismic desig^va ue at 1.Os SA -Additional Information Name Value Description SDC _ Se smic oesign categcry Fa 1.2 Site ampti eat.on factor at 0.2s F. 1 L21 Site arr_pIr9caton factor at'.;ts CRS 0.905 Coeitctent 0"nsk(0,25) CI% 0.882 Coe"Ticiem of nsk(1.0s) AAG24-021 8947 Buttonwood Lane NE,Olympia,WA 98516 22 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL ASCE7-16 Continued PGA Q.8@9 tdCEG oeak grcu^d 3Cve eration F:,GA 1.2 Site am.plrrcat on factor at=GA PGAr� Q.802 Site rrodried peak ground acceleabon T 1 Lorg-perod tr3nsiton perod's) SsRT I.c`9 Pronabi stic-sk-.argetec grouna motion(0.2s) SsUH 1.722 Fame--d unrorm-hazard soectal aoce<eration j24:probability o` exceeds-ce y]year-1 SsC 1.7'5 Factc-ed deterrnin stic accelerat on value(0.2si S1 RT 0.579 Procab, stic-sk-targetec grouna motor 31UH 0.0-4 F3cic%-dunrorm-hazardsoectal3ceafrationi2`horobabilityo= exceedar.ce -5_-years- S 1 D Q.8Z7 Factord determin sac accelerat.on value-1.0s1 PGAd 0.7 Z Facto ed determ n s8c 3roele-at on value-P 3A: The resu"s ndicareo here DO NOT refrect any state ar iocai amerrdm-nrs ro l,�va-lues cr any aersneanen tin-a made during Ire ba9dir9y code adoption; pro.ess.Users should oonfirm any output obwred f om.itivs r roi worh tme ioca.Autrortty hay.ng Jirisd-snon tefere proceeding with dessgn. I i I AAG24-021 8947 Buttonwood Lane NE,Olympia, WA 98516 23 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL SLOPE MODELS STATIC MODEL A-A' xx 4cc 4 . co U Li o � s z Q y Q Q 8 0 M fh N 8 N C ae pp J Q Q � C t7i a g x a cu A W w .i► v I c n r oLU v U AAG24-021 8947 Buttonwood Lane NE,Olympia, WA 98516 24 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL DYNAMIC MODEL A-A' � c 13 N n E ? y h a m uj Q g g N H; 8 N � 1 Itl a fCO YY o J o C � a wW e : 0J 2 as W � en a N U O AAG24-021 8947 Buttonwood Lane NE,Olympia, WA 98516 25 Phone#: (360)491-5155 Cell#:(360)481-6677 ALL AMERICAN GEOTECHNICAL FIGURE 1 VICINITY MAP 1.23606'00'lV 111,05 06'W 123°04'00'w W0584 031 03 00'w q-Et34� 7.a- 04 Zri .,'. z _yt ._ :� '.'err rR•.aoc S I 1� se�lBrxey r � -, rr /p,t _ rrc Coo I " •_ ` + -- - ,- \-• _ - 4 77 _. qosii !Po fir, :.'I �y771J we.I r rr 1 r tt,ab'uu' u t r o5 00'W 121'04 00"�Yyl W6984 12110300'W 1'rmrl frva-pP?.4: 1�'maod rnrrrr'r F.ritmu�a^�trs m:il I .I AAG24-021 8947 Buttonwood Lane NE,Olympia, WA 98516 26 Phone#: (360)491-5155 Cell#:(360)481-6677 I O r � NOTES �� J This is not a survey. This map is a presentation of i /✓ information from county,state,and/or federal 1 j� / Scale: 1-inch=50-tect agencies,client provided information,and onsite J U Countour Interval=2-feet observations. / � r Water is community sourced. Site Soil (� / %• ; Ab—Alderwood gravelly sandy loam, 8 to 15 percent slopes. Ac—Alderwood gravelly sandy loam, 15 to 30 percent slopes. I / Site Geology Qv Vashon Stade glacial till(Pleistocene) QXa Vashon Stade advance outwash(Pleistocene) ( / o_r hr t 0 s� J 'jig 07, t I��� I h0 .rc,ncr.nt Gwo-ym�� :aav Cos d Goo�o Curtis an Cushman 411 American Geotechnical,Inc. Project Drawn By: Site Plan 32104-50-00091 Figure Permit Number: Parcel Number: 8947 Buttonwood Lane NE Number: BWJ Proposed Home Z Olympia,Washington 98516 AAG24-021 3/15/2024 Union,WA Applicant Name: Alderwood Golf Course Lot 91 Site Address: 141 F Jack Pine Lane Page 27 FILTER FABRIC MATFR—BD•MADE ROLLS USE STAPLES OR WIRE RING TO ATTACH FABwc To OWRE FABRI14 N EQUI WIRE — �FABPoC OREWNALEM GENERAL EROSION CONTROL NOTES: ? 1. EROSION CONTROL MEASURES SHALL BE IN RACE PRIOR TO THE BEGINNING OF CONSTRUCTION.THE PROJECT ENGINEER AND THE COUNTY sa ��� SMALL INSPECT AND APPROVE THE INSTALLATION OF 12 INCH MINIMUM DIAMETER STEEL ROD EROSION CONTROL MEASURES PRIOR TO BEGINNING CONSTRUCTION. (STRAP)CLAMPED SECURELY TO PIPE 2.EROSION CONTROL MEASURES ARE NOT LIMITED TO THE ITEMS MAR ON THIS PLAN.THE CONTRACTOR IS RESPONSIBLE FOR THE CORRUGATED TIGHTLINE 41NCH f INSTALLATION AND MAINTAIN NCE OF ALL EROSION CONTROL MEASURES, MINIMUM,6 INCH SUGGESTED NO SILTATION OF EXISTING OR PROPOSED DRAINAGE FACILITIES SMALL BE ALLOWED.CARE SHALL BE TAKEN TO PREVENT MIGRATION 2'D(4'WOOD POSTS,STANDARD OR WRY BOTTOM OF FILTER OF SILTS TO OFF SITE PROPERTIES. `? BETTER OR EQUAL ALTERNATE: MATERIAL IN 0•X12•TRENCH A..T: Jp,+r•,. AO FF�. STEEL FENCE POSTS 3.THE CONTRACTOR SHALL MAKE DAILY SURVEILLANCE OF ALL EROSION CONTROL MEASURES AND MAKE ANY NECESSARY REPAIRS OR ADDITIONS '!ihD TO THE EROSION CONTROL MEASURES.THE CONTRACTOR SHALL PROVIDE `;^ •,O:'�r'' < 1F}'rdiN: ADDITIONAL EROSION CONTROL MEASURES AS DETERMINED NECESSARY • �` XS.. ; u„ r BY THE COUNTY INSPECTOR AND/OR THE PROJECT ENGINEER FAILURE FILTER FABRIC R TO COMPLY WITH ALL LOCAL AND STATE EROSION CONTROL �: :y�'1 .Ca?•f'A: +,q..�.� Alt,.: RE OUIREMENTS MAY RESULT IN CIVIL PENALTIES BEING LEVIED ,'J'`Y%# `•'_�+�' 1 •'Y'Ti!'�� 2•XTX14 GAME WARE 2V�. W.`:;!' /N��Yy�1^W FABRIC OR EQUIVALENTAGAINST THE CONTRACTOR ANDATR PROJECT OWNER `.."U:'r5 NX"i yn'„r.D•:t, `"':.' `*^'.+ '�•,-'�'+ 2' F. L;✓t!•_ V '!. 1i•�..'I 1'�S.,,i�y'.J GROUND SURFACE Bd 4.DURING THE WET SEASON(NOVEMBER TO MARCH)ALL DISTURBED SOILS YM1 h"y ..'Ji+��gti A a'% `+ ,�;L6'yf4'•' SHALL BE STABILIZED WITHIN 48 HOURS AFTER STOP OF WORK.EROSION 'Y'"TXC +t> k`�+.;L,�S,hv`. ,.�:kti��'tT•Sf,• PROAM N4%1 1/T WASHED CONTROL MEASURES SHALL INCLUDE,BUT NOT BE LIMBED TO, tl.!'.F`tl D'!L�"'Lt,1�l•• :.Yk NY.,i COVERING THE EFFECTED AREA INCLUDING SPOIL PILES MATH Y GRAVED BAGtFB1.IN TRENCH 1T •. ^'.S'S( :?✓+ y'Y wr'—ONe SIDES FILTER PLASTIC SHEETING,STRAW MATTING,JUTE MATTING,STRAW MULCH, FENCEEFABRIC ON THEF SURFACE fi OR WODD CHIPS.SEEDING OF THE DISTURBED AREAS SHELL TAKE •�,�1�v1"� PLACE AS WEATHER PERMITS. TIGHTLINE ANCHORED WITH TWO, •VrOW P03T8 5.ALL SEEDED OR SODDED AREAS SHALL BE CHECKED REGULARLY 3 FOOT REBAR LENGTHS OR BOLTS. AT:STEEL FENCE POSTS TO MAKE SURE VEGETATIVE COVERAGE IS COMLETE.AREAS SHALL BE REPAIRED,RESEEDED,AND FERTILIZED AS REWIRED. FILTER FABRIC FENCE NOTES: 6.TRACKING OF SOIL OFFSITE WILL NOT BE ALLOWED.IF ANY SOL IS 1.FIL R FABRIC SHALL M FORCHASED M/A CONTINUOUS ROLL CUT TO TRACKED ONTO A COUNTY STREET,IT SHALL BE REMOVED BY THE END THE LENGTH OF THE BARRIER TO AVOID USE OF JOINTS.WHEN JOINTS OF THAT WORKING DAY.ANY FURTHER TRACKING OF MUD WILL THEN ARE NECESSARY,FILTER CLOTH SHALL BE SPLICED TOGETHER ONLY AT A SUPPORT POST WRH A MINIMUM&INCH OVERL-AP AND SECURELY BE PREVENTED BY SWEEPING OR WASHING OF THE VEHICLES TIRES FASTENED AT BOTH ENDS TO THE POST. BEFORE DRIVING ON A COUNTY STREET. 2.POSTS SHALL BE SPACED A MAXIMUM OF 8 FEET APART AND DRIVEN 7.NO MORE THAN 500 LF OF TRENCH ON A DOWNSLOPE OF MORE THAN 5 SECURELY INTO THE GROUND(MINIMUM OF SU INCHES), PERCENT SHALL BE OPENED AT ONE TIME. 3.A TRENCH SHALL BE EXCAVATED APPRONMATELY 81NCHES WADE AND 12 8.EXCAVATED MATERIAL SHALL BE PLACED ON THE UPHILL SIDE OF TRENCHES. C FLARE END SECTION INCHES DEEP ALONG THE LINE OF POSTS AND UPSLOPE FROM THE BARRIER 9.TRENCH DE WATERING DEVICES SHALL BE DISCHARGED IN A MANNER THAT WILL I ( QUARRY SPALL r rt-•„•.;,.�'T 4.WHEN STANDARD 1NALL B FASTENED FILTER FABRIC IS USEO.A WIRE MESH f OR ENERGY Rf',>ir.. OF THE O FENCESTSU ING HEA WIFE A THEUPSLOPEINCH 910E NOT ADVERSELY OPERTI FECT FLOWING STREAMS.DRAINAGE SYSTEMS OR y A� - 'x V„�yps"�i O NG,TIE POSTS USING HOG RINGS. THE RIE SH IL AT LFJ16T WO T OFFSITE PROPERTIES. DISPERSION DEVICE sly W."R '�`'"'Jn(t;.�. nilAF� LONG,TIE WIRES ONi MOG RINGS.THE WIRE 6HALL FJ[TENIINTO THE .f•{,T �^.. ilf�':..- `'-'':i - TRENCH),MINIMUM OF M INCHES AND SHALL NOT EXTEND MORE THAN 36 10.ALL STORM SEWER INLETS RECEIVING RUNOFF FROM THE PROJECT DURING INCHES ABOVE THE ORIGINAL GROUND SURFACE. CONSTRUCTION SHALL BE PROTECTED SO THAT SEDIMENT-LADEN WATER GRASS-LINED SWALE SHOULD BE A 5.THE STANDARD STRFNGTH FILTER FABRIC SHALL BE STAPLED OR WIRED WILL BE FILTERED BEFORE ENTERING THE CONVEYANCE SYSTEM. MINIMUM ONE FOOT WIDE AT THE TO THE FENCE AND 20INCHES OF FABRIC SHALL BE EMENDED 11.ALL OFF-SITE CATCH BASINS IMMEDIATELY ADJACENT TO THE SITE BOTTOM AND ONE FOOT DEEP WITH INTO THE TRENCH.THE FABRIC SHAIL NOT EXTEND MORE THAI]8 INCHES ABOVE THE ORIGINAL GROUND SURFACE.FILTER FABRIC SHALL SHALL BE PROTECTED FROM SILTATION. A MAXIMUM SLOPE OF 5 PERCENT. NOT BE STAPLED TO THE EXISTING TREES. MINIMUM 4 FEET 12.ALL DISTURBED AREAS SHALL BE SEEDED OR SODDED UPON COMPLETION LEVEL SECTION 8.WHEN EXTRASTRENOTH FILTER FABRIC AND CLOSER POST SPACING IS OF WORK.THE CONTRACTOR SHALL BE RESPONSIBLE TO ENSURE THAT USED.THE WIRE MESH SUPPORT FENCE MAP BE ELIMINATED,IN SUCH COMPLETE COVERAGE OF THE DISTURBED AREAS IS PROVIDED 8 THAT A CASE,THE FILTER FABRIC IS STAPLED OR WIRED DIRECTLY TO THE GROWTH OF THE VEGETATION IS ESTABLISHED. GEOTEXTILE FABRIC POSTS WITH ALL OTHER PROVISIONS OR ABOVE NOTES APPLYING. T.FLTER FABRIC FENCES SHALL r T BE REMOVEO BEFORE THE UPSLOPE 13.CATCH BASINS SHALL TRAP SEDIMENT OR FILTER FABRIC MUST BE AREA HAS BEEN PERMANENTLY STABNZED. PLACED UNDER GRATE UNTIL VEGETATION IS ESTABLISHED. 8.FILTER FABRIC FENCES SHALL BE INSPECTED IMMEDIATELY AFTER EACH RAINFALL AND AT LEAST ONLY DURING PROLONGED RAINFN.L.ANY REQUIRED REPAIRS SHALL BE MADE IMMEDIATELY. All American Geotechnical,Inc. Dawn By: Figure Erosion Control Notes PenDit Number: Parcel Number 32104-50-00091 8947 Buttonwood Lane NE BWJ 3 Revisions: Olympia,Washington 98516 4 Proposed Home Revisions: Union,Washington Applicant Name: Alderwood Golf Course Lot 91 Site Address. 141 E Jack Pine Lane !'agc 28