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Home My WebLink AboutGEOtech BLD2006-00995 - BLD Engineering / Geo-tech Reports - 7/10/2006 t T t t �oN STArFo� MASON COUNTY �P MCp PUBLIC WORKS DIRECTOR/COUNTY ROAD ENGINEER A N Shelton, Washington 98584 O Y O Y 1864 DATE: August 14, 2006 INTER-DEPARTMENTAL COMMUNICATIONS TO: Rebecca Hersha PARCEL # 12221-24-90041 FROM: John Sliva, Programs Engineer-PW BUILDING PERMIT NUMBER: BLD2006-00995 SUBJECT: Geo-Tech Report Review NAME: Ison Jim Rebecca, The Geotechnical Report prepared for the proposed new single-family residential development located at 451 East Victor Road near Belfair has been received and reviewed by Public Works. The proposed residence will be built on the levelest portion the lot approximately 40 feet north of the east west access road. The steepest portion of the site has slopes approaching 66% approximately 75 feet south of the proposed building location. Slope stability was modeled in both static and dynamic conditions for the residence. As a result, there is a need for a building setback of 30 feet from the face of slopes greater than 40%. It is the author's opinion that the site is suitable for the proposed project. The southern slope will not be affected by the proposed structure. If their analysis and recommendations are followed, they do no anticipate any on site or off site impact from the construction. Adequate erosion and sediment control features need to be implemented during land disturbing activities to protect neighboring properties and State waters from adverse stormwater runoff impacts. The migration or release of silty water or mud from the applicant's property will be considered a violation of County and State water quality protection regulations. The report appears to satisfactorily address County requirements for Geotechnical Reporting. Recommendations contained in the report should be incorporated into the site development plans and made conditions for permit issuance. Please feel free to contact me at 724 if you have any questions regarding these comments, or if you feel any features need further discussion or attention. aerelSiny, Sliva Programs Engineer t ' O N N 0 Cl O N O T22NRIW 21 160 140 68420 E VICTOR RD • i � t GEOTECHNICAL REPORT 451 EAST VICTOR ROAD BELFAIR, WASHINGTON PREPARED FOR S TEPHEN JOHNS ON, INC. BY GEOTECHNICAL TESTING LABORATORY OLYMPIA, WASHINGTON JULY 10, 2006 t �'''� p (may"• EOTECHNICAL TE'Ad tNG LABORATORY CONTACT INFORMATION PREPARER INFORMATION GTL PROJECT NuMBER: 06-2631-06 ADDRESS: 10011 BLOMBERG STREET SOUTHWEST OLYMPIA,WASHINGTON 98512 TELEPHONE: (360)754-4612 FACSIMILE: (360) 754-4848 EMAIL ADDRESS: GEOTESTLAB@COMCAST.NET CLIENT INFORMATION CLIENT: STEPHEN JOHNSON,INC. CONTACT: STEVE JOHNSON TELEPHONE: (360)275-6734 FACSIMILE: (360) 275-6775 MAILING ADDRESS: P.O.BOX 488 BELFAIR,WASHINGTON 98528 SITE ADDRESS: 451 EAST VICTOR ROAD BELFAIR,WASHINGTON 98528 PARCEL NUMBER: 122212490041 GPS LOCATION: N470 22.935' W1220 48.676' 10011 Blomberg Street SW,Olympia, WA 98512 2 Phone#: (360)754-4612 Fax#: (360)754-4848 MASON COUNTY DEPARTMENT OF COMMUNITY DEVELOPMENT o ,MU Planning Division i P O Box 279, Shelton, WA 98584 �p Doti (360)427-9670 1864 REQUEST FOR ADDITIONAL INFORMATION une 19, 2006 JIM ISON P.O. BOX 488 BELFAIR WA 998528 Parcel No.: 122212490041 Project Description: CONSTRUCT NEW SFR Dear Applicant: You have submitted a permit application (case no. BLD2006-00995) for proposed construction or development in the county. Upon review of your application, I require additional information to complete the permit review process. Therefore, review of your application will not proceed until the necessary information is provided (see the comment section of this letter for details.) Once the information is submitted and the application is complete, I will continue to process your application accordingly. If the additional information is not provided to the County within 180 days of this request, the application shall expire and no further action on the proposed development shall take place. Please contact me at (360) 427-9670, ext. 593 if you have questions. Sincerely, Rebecca Hersha Land Use Planner Mason County Planning Department 6/19106 1 of 2 BLD2006-00995 GEOTECHNICAL EOTE/ NCAL TESTING LABORATORY TORY SCOPE OF UNDERSTANDING STEPHEN JOHNSON,INC. P.O.Box 488 BELFAIR,WASHINGTON 98528 RE: GEOTECHNICAL REPORT 451 EAST VICTOR ROAD BELFAIR,WASHINGTON 98528 PARCEL 122212490041 N470 22.935' W 1220 48.676' Mr. Johnson: As per your request, we have conducted a soils exploration, foundation evaluation, and slope stability analysis for the above-mentioned parcel. The results of this investigation,together with our recommendations, are to be found in the following report. We have provided three copies for your review and distribution. Data has been carefully analyzed to determine soils bearing capacities, footing embedment depths, and building setback distances. The results of the exploration and analysis indicate that conventional spread and continuous wall footings appear to be the most suitable type of foundation for the support of the proposed structure. Some variability was encountered in comparing the soil profiles of the site. Net allowable soil pressures, embedment depth, and total expected settlements have been presented for the site later in the report. 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. Respectfully Submitted, GEOTECHNICAL TESTING LABORATORY Wasy c t P"y 1�0'4�4AT' Harold Parks, L.G., L.E.G. <0 Engineering Geologist w Senior Engineering Geologist �. 82T c o used Ge HAROLD PARKS K� -31-00 10011 Blomberg Street SW, Olympia, WA 98512 3 Phone#:(360) 754-4612 Fax#: (360) 754-4848 . GEOTECHNICAL, 1 STtNG'r LAwRATORY TABLE OF CONTENTS CONTACTINFORMATION.....................................................................................................................................2 SCOPE OF UNDERSTANDING...............................................................................................................................3 TABLEOF CONTENTS............................................................................................................................................4 INTRODUCTION.......................................................................................................................................................5 SITECONDITIONS...................................................................................................................................................6 SurfaceConditions..................................................................................................................................................6 SiteGeology............................................................................................................................................................7 SiteSoils.................................................................................................................................................................7 SubsurfaceExplorations.........................................................................................................................................8 SubsurfaceConditions............................................................................................................................................8 SlopeStability.........................................................................................................................................................8 CONCLUSIONS AND RECOMMENDATIONS......................................................................................................9 General....................................................................................................................................................................9 LANDSLIDE—EROSION HAZARD AREA.......................................................................................................... 10 Classification ........................................................................................................................................................ 10 SlopeStability....................................................................................................................................................... 10 BuildingSetback................................................................................................................................................... 11 Seismic—Liquefaction Hazard............................................................................................................................. 13 ErosionControl..................................................................................................................................................... 14 EARTHWORK......................................................................................................................................................... 14 SitePreparation..................................................................................................................................................... 14 StructuralFill........................................................................................................................................................ 15 Suitabilityof Onsite Soils as Fill.......................................................................................................................... 15 Cutand Fill Slopes................................................................................................................................................ 15 FoundationSupport............................................................................................................................................... 16 FloorSlab Support................................................................................................................................................ 16 RetainingWalls..................................................................................................................................................... 17 Slope Inclination: Equivalent Fluid Pressure........................................................................................................ 17 RetainingWall Alternatives.................................................................................................................................. 18 SiteDrainage......................................................................................................................................................... 18 SepticImpact......................................................................................................................................................... 18 LIMITATIONS......................................................................................................................................................... 19 FIGURE 1 VICINITY MAP.....................................................................................................................................20 10011 Blomberg Street SW, Olympia, WA 98512 4 Phone#: (360) 754-4612 Fax#: (360) 754-4848 GEOTECHNWAt, TESTING LABORATORY INTRODUCTION This report summarizes the results of our geotechnical consulting services for the single-family residence to be located along the west-facing slope overlooking North Bay, approximately 5.0 miles sputheast of Belfair, Washington. The location of the site is shown relative to the surrounding area on the Vicinity Map,Figure 1. r S .� `c. .f.. y.• :n, t S�� fir k t ,1 LY Our understanding of the project is based on our discussions with you and our explorations and review of the site. We unders hat the parcel is to be developed by constructing a single-family residence. The site is accessed d. In general, grading will consist of the excavation of the footings and un ation. The approximate- t layout of the site is shown on the Site Plan,Figure 2. The site slopes toward the northeast from the proposed building location. Theme w' is nearly 66 per '�over 75 feet south of the � building location. Thereforemuir that a geotechnical report be pain accordance with the Critical Areas Ordinanee.�— The purpose of our services is to evaluate the surface and subsurface conditions at the site as a basis for providing geotechnical recommendations and design criteria for the project and to satisfy the requirements of the Mason County Critical Areas Ordinance. Geotechnical Testing Laboratory is therefore providing geologic and hydrogeologic services for the project. Specifically, our scope of services for this project will include the following: 1. Review the available geologic,hydrogeologic, and geotechnical data for the site area. 2. Conduct a geologic reconnaissance of the site area and surrounding vicinity. 3. Investigate shallow subsurface conditions at the site by observing the exposed soil and reviewing published well logs. 4. Evaluate the landslide and erosion hazards at the site per the Mason County Critical Areas Ordinance regulations. 5. Provide geotechnical recommendations for site grading including site preparation, subgrade preparation, fill placement criteria (including hillside grading), temporary and permanent cut and fill slopes, and drainage and erosion control measures. 10011 Blomberg Street SW,Olympia, WA 98512 5 Phone#: (360)754-4612 Fax#: (360)754-4848 GEOTECHNic.A L TESTING LABORATORY SITE CONDITIONS SURFACE CONDITIONS The site is surrounded by a forested y parcel on the east and north, a residential parcel to the west, and Victor Road to the south. The site has western exposure. We conducted a reconnaissance of th site area on June 29 2006. Site elevations range from approximately 17 *to 226 feet. dr The building area of the site has U vegetation common to the Northwest. + The vegetation includes fir, hemlock, alder, madrone, maple, and cedar trees as 1, well as bracken fern, sword fern, Oregon grape, daisy, foxglove, salal, Scot's broom, and blackberry. At the time of the site visit, active erosion was not observed at the proposed '? •,.r building location or throughout the site. Deep-seated slope instability was not observed onsite. No evidence of deep-seated instability was observed at the proposed building location or throughout the site. Sloughing and raveling were not observed along the well- vegetated slopes. Surface water flow was not observed at or near the proposed building location. Seepage was not observed onsite. The general topography of the site area indicates that drainage flows toward the west from the proposed building location. ap$ } s sw; L-s •ti. 10011 Blomberg Street SW,Olympia,WA 98512 6 Phone#:(360)7544612 Fax#: (366)754-4848 SITE GEOLOGY The site is generally situated within the extent of recent glacial deposits. The existing topography, as well as the surficial and shallow subsurface soils in the area, are the result of the most recent Vashon stade (stage) of the Fraser glaciation that occurred between about 9,000 and 11,000 years ago, and weathering and erosion that have occurred since. A description of the surficial soils is included in the"Site Soils" section of this report. In general, the soils are composed of Vashon glacial material. The Geologic Map of Washington — Northwest Quadrant (2002) has mapped the site geology as glacial till deposits(Qgt)of continental glacial origin. The report reads: Till— Unsorted, unstratified, highly compacted mixture of clay, silt, sand, gravel, and boulders deposited by glacial ice; may contain interbedded stratified sand, silt, and gravel. Includes part of the Vashon Dry undivided. SITE SOILS \ The Soil Survey of Mason County, Washington, USDA Soil Conservation a (1960) has mapped the western site soils as an Everett very gravelly sandy loam, 15 to 30 percent slope urvey reads, This very deep, somewhat excessively drained soil on terraces outwash plains formed in the glacial outwash stage of the most recent Fraser glaciation. Permeability is rapid (up to 20 inches per hour) with a high rate of water transmission. These soils are typically classified as a "Group A" relative to surficial runoff. The soils are further characterized as having medium runoff potential and moderate water erosion potential. Shrink-swell potential is described as low due to the low organic content. We observed no active erosion or slope disturbance in the site area during our reconnaissance. rr I M I ` J* rn f �eL� � ^I .�. �� {�•�f�-JM� e � '_jam. �.k� �• I"- r�'.��l .� ..J 'rig. _ _-' 10011 Blomberg Street SW,Olympia, WA 98512 7 Phone#: (360) 7544612 Fax#: (360)754-4848 r • The Soil Survey of Mason County, USDA Soil Conservation Service(1960) has mapped the southeastern site soils as a Sinclair shotty loam, 5 to 15 percent slopes(So)and is described as follows: This gently rolling and rolling soil is the dominant soil of the Sinclair series. A thin, very dark brown acid, organic mat is on the surface. The upper 3 to 5 inches of mineral soil is medium acid, granular and friable, grayish-brown shotty loam (very dark grayish-brown when moist). This is underlain by medium acid, friable and granular, light brownish-gray shotty loam that continuous to depths of 10 to 12 inches. The shot are grayish and very pronounced. This shotty loam is underlain by very pale brown gravelly loam subsoil that reaches to depths of 20 to 24 inches. It is faintly stained and mottled with yellowish brown and light gray and is massive or <<' \ has a weak subangular blocky structure. The gravelly loam is hard when dry but friable when moist; it contains much less shot than the horizons above. Between the subsoil and the underlying till is a more sandy layer, 3 to 6 inches thick, that is firm and moderately mottled, contains very few shot, and is massive. The firm till very abruptly changes to cemented till at depths of 28 to 42 inches. The upper 2 to 6 inches of cemented till is, normally, a sequence of thin plates consisting of mottled and stained, strongly cemented, grayish gravelly sandy loam. To depths of many feet, the till is granitic, light gray, strongly cemented, and strongly acid. The Sinclair soils have typically developed from very compact vashon gravelly till. Surface drainage is well to moderately well established. Internal drainage is restricted by the substratum of cemented till. Typically, there is no occurrence of a high water table. The soils are not considered hydric. SUBSURFACE EXPLORATIONS Subsurface conditions at the site were evaluated by observing the exposed building site soil, reviewing available well logs, and observing the slopes. s8%tic groundwater was not encountered resumed deep, and is beyond the ort. Depth to competent soil is appo;lately 8 inches througt the proposed building location. SUBSURFACE CONDITIONS In general, undisturbed dense Everett gravelly sandy loam and Sinclair shotty loam were observed in the undisturbed portions of the site. At the proposed building location, glacial material was observed below the surficial soils. Based on the site topography and the nature of the near-surface soil, seasonally perched groundwater conditions may not be expected during periods of extended wet weather. 2 SLOPE STABILITY ' li"rcent_,or-greater relief occur on po io si e, Mason County requires that a i geologic hazards report be completed according to the Critical Areas , Ordinance. The near-surface soils are in a dense to very dense condition except at ;S; the ground surface. The surficial soils are generally in a medium .i dense condition. ; j •-"""'� 10011 Blomberg Street SW,Olympia, WA 98512 8 Phone#:(360)754-4612 Fax#: (360)754-4848 GEE TECHNICAL TESTtNO LABORATORY In general,the undisturbed native soils of the site consist of a mixture of variable amounts of sand, silt,and gravel. These soil materials are in a dense condition except where they have been disturbed by weathering activity. These soils are generally stable relative to deep-seated failure. Deep-seated landslide activity was not observed onsite at the time of our investigation. Weathering, erosion, and the resultant sloughing and shallow landsliding are natural processes that can affect steep slope areas. Instability of this nature is typically confined to the upper weathered or disturbed zone, which has been disturbed and has a lower strength. Surficial raveling and sloughing were not observed along the southern slope. Significant weathering typically occurs in the upper 2 to 3 feet and is the result of oxidation, root penetration, wet/dry cycles, and freeze/thaw cycles. Erosion in steep slope areas such as this can be reduced by encouraging vegetation and discouraging runoff from the steep slopes. Erosion control recommendations for the sloping areas are provided in the"Erosion Control"section of this report. OEM -, Y 5`i .R yp Llvct-v 9' CONCLUSIONS AND RECOMMENDATIONS GENERAL of our site reconnaissance. subsurface observations, and our experience in the area. it is our e is suitable for the proposed project. The southern slopUNNObe affected by the proposed X ,Wstru The proposed structure will not undermine adjacent slopes. Proper drainage control measures will reduce or eliminate the potential for erosion in this area and improve slope stability. The hazards of the landslide area can be overcome in such a manner as to prevent harm to property and public health and safety, and the project will cause no significant environmental impact for the life of the project. In general, the site soils observed at the site may be suitable for use as structural fill material. Saturated soil conditions are associated with these soils during or following extended periods of rainfall. However, to reduce grading time and construction costs, we recommend that earthwork be undertaken during favorable weather conditions. 10011 Blomberg Street SW,Olympia, WA 98512 9 Phone#: (360)754-4612 Fax#: (360) 754-4848 G + OTECHNICAL TESTtNG LABORATORY Conventional construction equipment may be utilized for work at the site. Conventional spread footings may be utilized at the site for support of the structure. We do recommend that roof and footing drains be installed for the structure with conventional spread footings. A vapor barrier is recommended for all slabs-on-grade. Pertinent conclusions and geotechnical recommendations regarding the design and construction of the proposed single-family residence are presented below. �Jc s" e LANDSLIDE - EROSION HAZARD AREA CLASSIFICATION The Mason County Critical Areas Ordinance (17.01.100) defines a landslide hazard area as one containing slopes equal to or greater than 40 percent with more than a 10-foot vertical relief. The southern slope approaches 66 percent with a vertical relief in excess of 10 feet. Based on the preceding,this site does meet the technical criteria of a landslide hazard. The Mason County Critical Areas Ordinance(17.01.104)defines an erosion hazard area as: Areas in Mason County underlain by soils which are subject to severe erosion when disturbed. Such soils include, but are not limited to, those for which potential for erosion is identified in the Soil Survey of Mason County, USDA Soil Conservation Service, 1960, or any subsequent revisions or additions to this source. These soils include, but are not limited to, any occurrence of River Wash ("Ra') or Coastal Beaches ("Cg') and the following when they occur on slopes 1 S%or steeper: a.Alderwood gravelly sandy loam ("Ac"and"Ad') b. Cloquallum silt loam("Cd') c. Harstine gravelly sandy loam ("Hb') d. Kitsap silt loam ("Kc') The soils at the site are mapped as Everett gravelly sandy loam (Ek)and Sinclair shotty loam (So). This site does not meet the technical criteria of an erosion hazard area. SLOPE STABILITY Based on our field observations, explorations, and our experience with the soil types encountered on the property, we conclude that although portions of the slopes on the lot approach 66 percent,the proposed building location is generally stable relative to deep-seated failure at the present configuration. 10011 Blomberg Street SW,Olympia,WA 98512 10 Phone#: (360) 754-4612 Fax#: (360)754-4848 The Coastal Zone Atlas, Volume 9, Mason County(MA-12)maps the site as Vashon glacial till (Qvt). Foundation ,as " lbility is described as "good." The slope stability is described as kk: The Relative Slope Stability of the Southern Hood Canal Area, Washington, (1977)describes the site area as Class 3. Class 3 is described as: Areas inferred to be unstable because slopes, generally greater than 15 percent, are underlain by weak, unstable materials in which old or recently active landslides have occurred. Includes areas of sand and gravel on top of impermeable silt and clay, mostly along steep valley sides. Excavation and backfilling will occur based on appropriate engineering and earthwork recommendations found in the following"Earthwork" section. Grading in the building portion of the site should be conducted in accordance with geotechnical recommendations provided herein. As previously discussed, weathering, erosion, and the resultant surficial sloughing and landsliding are natural processes that affect slope areas. Significant weathering typically occurs in the upper 2 to 3 feet and is the result of oxidation, root penetration, wet/dry cycles, and freeze/thaw cycles. Over-excavation may be necessary to ensure the removal of deleterious material. These processes can be managed and the risk reduced through proper construction of the residence. Erosion control recommendations in the slope and buffer areas are provided in the "Building Setback" and "Erosion Control"sections of this report. BUILDING SETBACK A building setback from landslide hazard areas is required unless evaluated and reduced by an engineering geologist or a licensed professional engineer. Based on our geotechnical evaluation of the site and our experience in the area, a building setback will be needed for this lot. The building setback may be measured from the bottom of the footing to the face of the steep slope in accordance with the International Building Code (1805.3.1). The following figure represents a shear angle for the gravelly sandy loam. Shear angle and cohesion are variables used to model the site. Peak Shear Stress vs. Normal Stress 410----- _ 2500 Al N a 2000 a I N d N 1500 lC 47 L N Y 1000 10 a � 500 [-*-1/4ton' i-M ton -a-1 ton 0 0 500 1000 1500 2000 2500 3000 Normal Stress(psf) 10011 Blomberg Street SW,Olympia, WA 98512 11 Phone#: (360) 754-4612 Fax#: (360)754-4848 Setback L L Slope stability was modeled using the GeoStudio 2004 (version 6.17) in both Steve Johnson -- Ison Site -- Slope A static and extreme dynamic conditions .2--67 (ca = 0.3). Factors of safety were determined using Bishop's, Janbu, and the Morgenstern-Price methods. The 0 site was modeled using a gravelly sandy , loam. The gravelly sandy loam material . was determined to have a unit weight of . 132 pcf, cohesion of 200 psf, and a shear angle (�) of 41°. Under static conditions, the slope was not susceptible to shallow failure or • rL ' S susceptible to deep-seated failure. •0 Under dynamic loading, the 3,328 computations demonstrated that the I.' 0 slope is not susceptible to surficial 0 raveling or to large deep-seated failure. The following figure illustrates the , moment factor of safety for slope "A" 230 — ' under the existing conditions. The 220 figure is the solution of greatest concern 210 exhibits a nee or a m mg 200 set ac of 30 feet from the Tace of o 190 Description: Gravelly s opes grea er an 0 percent. All a 180 Cohesion: 200 foun ation elements shall be w 170 constructed on native material or Phi: 41 160 engineered fill material. The current 150 - building location meets the previous 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 requirements. Distance (ft) 10011 Blomberg Street SW,Olympia, WA 98512 12 Phone#: (360) 754-4612 Fax#: (360)754-4848 GEOTECHNICAL TESTING LABORATORY As previously discussed, weathering, erosion, and the resultant surficial sloughing and shallow landsliding are natural processes that affect slope areas. Surficial raveling, slumping, and sloughing were not observed along the southern slope. To manage and reduce the potential for these natural processes, we recommend the following: ➢ No drainage of concentrated surface water or significant sheet flow onto the sloped areas. ➢ No filling within the setback zone unless retained by retaining walls or constructed as an engineered fill. ➢ Vegetate exposed soil as soon as possible. SEISMIC—LIQUEFACTION HAZARD According to the Seismic Zone Map of the United States contained in the 2003 International Building Code(IBC), the project site is located where the maximum spectral response acceleration is 45 percent of gravity(g). 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 site area as site class C. Site class C is a very stiff soil or soft rock. Based on the subsurface conditions observed at the site,we interpret the site conditions to correspond to a seismic Soil Profile Type D, for Stiff Soil, as defined by Table 1615.1.1 (IBC). This is based on probing with a '/z-inch diameter steel probe rod. The shallow soil conditions were assumed to Be representative for the si a con itions eyon t e depths explored. Based on our review of the subsurface conditions, we conclude that the site soils are only mildly susceptible to liquefaction. The near-surface soils are generally in a dense condition and the static water table is located well below the surface. Shaking of the already dense soil is not apt to produce a denser configuration and subsequently excess pore water pressures are not likely to be produced. 10011 Blomberg Street SW,Olympia, WA 98512 13 Phone#: (360)754-4612 Fax#: (360)754-4848 GEO TECUNICALy TESTING LABORATORY EROSION CONTROL It is our opinion that the potential erosion hazard of the site is not a limiting factor for the proposed development. Removal of natural vegetation should be minimized and limited to the active construction areas. qlav 1 ca ing around the home is perrrftsible, but understory growth on th s s Wd be encouraged as much as possible as a deterrent to erosion. Hazard trees located on steep slopes may be removed only if the stumps remain deter erosion. Temporary and permanent erosion control measures should be implemented and maintained during construction and/or as soon as practical thereafter to limit the additional influx of water to exposed areas and protect potential receiving waters. Erosion control measures should include, but not be limited to, silt fences, berms, and swales with ground cover/protection in exposed areas. A typical silt fence detail is included on Figure 2. Any re-contouring of the site will create a need for erosion control measures as listed above. 7. k 44 - �� .iy , �°� •. .4 SYti 4 ��f. `If RSA, §,. i .. EARTHWORK SITE PREPARATION All areas to be excavated should be cleared of deleterious matter including any existing structures, debris, duff, and vegetation. Based on our observations, we estimate that stripping on the order of 8 to 14 inches will be necessary to remove the root zone and surficial soils containing organics. Areas with deeper, unsuitable organics n should be expected in the vicinity of depressions or heavy vegetation. Stripping depths of up to 2 feet may occur f \ in these areas. These materials may be stockpiled and later used for erosion control and landscaping. Materials that cannot be used for landscaping or erosion control should be removed from the project site. Where placement of fill material is required, the exposed subgrade areas should be proof-rolled to a firm and unyielding surface prior to placement of any fill. We recommend that trees be removed with the roots, unless located on a slope. Excavations for tree stump removal in any building area should be backfilled with structural fill,compacted to the density requirements described in the"Structural Fill"section of this report. 10011 Blomberg Street SW,Olympia, WA 98512 14 Phone#: (360)754-4612 Fax#: (360)754-4848 GEOTECHNICAL TESTING LABORATORY. If structural fill is needed, we recommend that a member of our staff evaluate the exposed subgrade conditions after vegetation removal and topsoil stripping are completed. Any soft, loose, or otherwise unsuitable areas delineated during foundation preparation or probing should be compacted, if practical, or over-excavated and replaced with structural fill,based on the recommendations of our report. STRUCTURAL FILL All fill material should be placed as structural fill. The structural fill should be placed in horizontal lifts of appropriate thickness to allow adequate and uniform compaction of each lift. Fill should be compacted to at least \ , 90 percent of MDD (maximum dry density as determined in accordance with ASTM D-1557) to within 2 feet of �1 subgrade and 95 percent MDD in the upper 2 feet. The appropriate lift thickness will depend on the fill characteristics and compaction equipment used. We recommend that the appropriate lift thickness be evaluated by our field representative during construction. The suitability of material for use as structural fill will depend on the gradation and moisture content of the soil. As the amount of fines (material passing No. 200 sieve) increases, soil becomes increasingly sensitive to small changes in moisture content and adequate compaction becomes more difficult to achieve. During wet weather,we recommend the use of well-graded sand and gravel with less than 9 percent(by weight) passing the No. 200 sieve based on that fraction passing the 3/4-inch sieve. If prolonged dry weather prevails during the earthwork and foundation installation phase of construction, a somewhat higher(up to 10 percent)fines content will be acceptable. 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. SUITABILITY OF ONSITE SOILS AS FILL Onsite soils may be considered for use as structural fill. In general, the native soils (sand, silt, and gravel) encountered on the site must have less than 10 percent fines (material passing the US No. 200 Sieve) to be suitable for use as structural fill. CUT AND FILL SLOPES All job site safety issues and precautions are the responsibility of the contractor providing services and/or work. The following cut/fill slope guidelines are provided for planning purposes. Temporary cut slopes will likely be necessary during grading operations. As a general guide,temporary slopes of 1.5 to 1 (horizontal to vertical) or flatter may be used for temporary cuts in the upper 3 to 4 feet of the glacially consolidated soils that are weathered to a loose/medium-dense condition. Temporary slopes of 1 to I or flatter may be used in the unweathered dense to very dense sands and gravel. These guidelines assume that all surface loads are kept at a minimum distance of at least one-half the depth of the cut away from the top of the slope and that significant seepage is not present on the slope face. Flatter cut slopes will be necessary where significant raveling or seepage occurs. Surface drainage should be directed away from all slope faces. All slopes should be seeded as soon as practical to facilitate the development of a protective vegetative cover, or otherwise protected. 10011 Blomberg Street SW,Olympia,WA 98512 15 Phone#: (360)754-4612 Fax#: (360)754-4848 GEO TECHNICAL TESTING LABORATORY IkE rr � .ft f FOUNDATION SUPPORT Where foundation elements are located near slopes between 5 and 30 percent, the footings shi" �\ minimum of 2 times the footing width from the djape face (horizontally), and founded in medium dense or denser native soils or properly prepared structural fill. We recommend a minimum width for isolated and continuous wall footings to meet IBC 2003. Footings founded as described above can be designed using an allowable soil bearing capacity of 2,000 psf(pounds per square foot) for combined dead and long-term live loads in areas of medium dense to dense soils. The weight of the footing and any overlying backfill may be neglected. The allowable bearing value may be increased by one-third for transient loads such as those induced by seismic events or wind loads. Lateral loads may be resisted by friction on the bases of footings and floor slabs and as passive pressure on the sides of footings. We recommend that an allowable coefficient of friction of 0.40 be used to calculate friction between the concrete and the underlying soil. Active pressure may be determined using an allowable equivalent fluid density of 200 pcf(pounds per cubic foot). We estimate that settlements of footings designed and constructed as recommended will be less than 1 inch, for the anticipated load conditions, with differential settlements between comparably loaded footings of '/2 inch or less. Most of the settlements should occur essentially as loads are being applied. However, disturbance of the foundation subgrade during construction could result in larger settlements than predicted. FLOOR SLAB SUPPORT Slabs-on-grade should be supported on medium dense or dense native soils or on structural fill prepared as described in the "Structural Fill" section of this report. We recommend that floor slabs be directly underlain by a minimum 6-inch thickness of coarse sand and/or gravel containing less than 5 percent fines (by weight). The drainage material should be placed and compacted to an unyielding condition. A synthetic vapor barrier may be used for the control of moisture migration through the slab, particularly where adhesives are used to anchor carpet or tile to the slab. A thin layer of sand may be placed over the vapor barrier and immediately below the slab to protect the liner during steel and/or concrete placement. The lack of a vapor barrier could result in wet spots on the slab, particularly in storage areas. 10011 Blomberg Street SW,Olympia, WA 98512 16 Phone#: (360) 754-4612 Fax#: (360)754-4848 GEOTECHNCCAL TESTING LABORATORY RETAINING WALLS Retaining walls may be utilized on the sloping portion of the site to retain fill material. The lateral pressures acting on the subgrade and retaining walls will depend upon the nature and density of the soil behind the wall. It is also dependent upon the presence or absence of hydrostatic pressure. If the adjacent exterior wall space is backfilled with clean granular, well-drained soil (washed rock), the design active pressure may be determined using an active pressure coefficient equal to 0.25 (Ka = 0.25). This design value assumes a level backslope and drained conditions as described below. Retaining walls located on or near the toe of a slope that extends up behind the wall should be designed for a lateral pressure, which includes the surcharge effects of the steep slope in proximity to the wall. Although not expected at this site,the following data is provided for planning purposes. For an irregular or composite slope, the equivalent slope angle may be determined by extending a line upward from the toe of the wall at an angle of 1 to 1 (Horizontal to Vertical)to a point where the line intersects the ground surface. The surcharge effects may be modeled by increasing the equivalent fluid pressure for flat ground by the percentage given in the following table: SLOPE INCLINATION: EQUIVALENT FLUID PRESSURE Slope Angle Percent Increase Equivalent Fluid Pressure Horizontal 0% 35 pcf 3H:1 V 25% 44 pcf 2H:I V 50% 53 pcf 1H:IV 75% 61 pcf If the walls are greater than 4 feet in height, exclusive of the footing, additional design considerations should be applied. Positive drainage,which controls the development of hydrostatic pressure, can be accomplished by placing a zone of coarse sand and gravel behind the walls. The granular drainage material should contain less than 5 percent fines. The drainage zone should extend horizontally at least 18 inches from the back of the wall. The drainage zone should also extend from the base of the wall to within 1 foot of the top of the wall. The drainage zone should be compacted to approximately 90 percent of the MDD. Over-compaction should be avoided as this can lead to excessive lateral pressures. A perforated PVC pipe with a minimum diameter of 4 inches be placed in the drainage zone along the basil* of the wall to direct accumulated water to an appropriate discharAwkation. We recommend that a non-woven geotextile filter fabric be placed between the drainage material and the remaining wall backfill to reduce silt migration into the drainage zone. The infiltration of silt into the drainage zone,with time,can reduce the permeability of the granular material. The filter fabric should be placed in such a way that it fully separates the drainage material and the backfi 11, and should be extended over the top of the drainage zone. 10011 Blomberg Street SW, Olympia, WA 98512 17 Phone#:(360) 754-4612 Fax#: (360) 754-4848 GEOTECHNiCAL 'TESTING LABORATORY Lateral loads may be resisted by friction on the bases of footings and as passive pressure on the sides of footings and the buried portions of the wall. We recommend that an allowable coefficient of friction of 0.40 be used to calculate friction between the concrete and the underlying soil. RETAINING WALL ALTERNATIVES Typically, block wall systems are more cost effective for long-term walls than the other options. Specific design criteria for these options can be provided at your request by the block manufacturers. SITE DRAINAGE XN en s, and sidewalks s ou from the resi+� fated Surface water runoff should be controlled by a system of curbs, berms, drainage swales, and/or catch t(J basins and tight-lined to the appropriate drainage facilities. We recommend that conventional roof drains be \\ installed. Footifk drains shall be installed for the single-family residence --'Me roof drain should not be *MnVeted.to the,faiating drain. For footing drains,the drain invert should be below the bottom of the footing. We recommend that the collected stormwater runoff be directed to the appropriate drainage facilities by tight-line. Drainage control measures are included on Figure 3. Onsite irrigation to lawn areas should be closely monitored. We do not expect any adverse affects on the recharge condition of the groundwater system. SEPTIC IMPACT The drainfield is located in the western portion of the site. We conclude the slope stability of the site will not be compromised by the septic drainfield location. Z. 1+{Yf,fir�, yi[F'niaaTT >M• y..t �, .17 10011 Blomberg Street SW,Olympia, WA 98512 g Phone#: (360)754-4612 Fax#: (360) 754-4848 GEO'TECHNICAL TESTING LABORATORY LIMITATIONS We have prepared this report for Stephen Johnson, Inc. as well as members of their design team for use in the design of a portion of this project. The data used in preparing this report, and this report, should be provided to prospective contractors for their bidding or estimating purposes only. Our report, conclusions and interpretations are based on data from others and our site reconnaissance, and should not be construed as a warranty of the subsurface conditions. This report is quantified as a micro-study and not a macro-study. Geotechnical Testing Laboratory and its personnel cannot be responsible for unforeseen and widespread geologic events (such as earthquakes, large-scale faulting,and mass wasting)beyond the scope of this project. Variations in subsurface conditions are possible and may occur with time. A contingency for unanticipated conditions should be included in the budget and schedule. Sufficient consultation should be made with our firm during construction to confirm that the conditions encountered are consistent with those indicated by the recommendations, for design changes should the conditions revealed during the work differ from those anticipated,and to evaluate whether earthwork and foundation installation activities comply with contract plans. If our analysis and recommendations are followed, we do not anticipate any on site or off site impact from the construction. It is our conclusion that potential landslide hazards from the landslide area can be overcome so as not to cause harm to property,public health and safety, or the environment. The scope of our services does not include services related to environmental remediation and construction safety precautions. Our recommendations are not intended to direct the contractor's methods, techniques, sequences, or procedures,except as specifically described in our report for consideration in design. If there are any changes in the loads, grades, locations, configurations, or types of facilities to be constructed, the conclusions and recommendations presented in this report may not be fully applicable. If such changes are made, we should be given the opportunity to review our recommendations and provide written modifications or verifications, as appropriate. { 'ry 1001 l Blomberg Street SW,Olympia,WA 98512 19 Phone#: (360)754-4612 Fax#: (360)754-4848 Ali/�\\`� ,•qE "AC��u �� yA v, KIWI �� 40. � : � • y 1/2 INCH MINIMUM DIAMETER STEEL ROD (STRAP)CLAMPED SECURELY TO PIPE CORRUGATED TIGHTLINE 4 INCH MINIMUM,6 INCH SUGGESTED 10CIPV6 i� �•:; %xd'v;+trl:,r•�,+t••Zri�" ..�..�•=ti�,y�•:r1:t�:Y.'?'•": :41 �y tf}w`Z,•.,�Rr �a"'i,Yi}t > '' 1t.1.;.^. •,.�:Y`,-7F:y" cF:d, tJ i.;'•;i1`s �.�.�xts''•! 'k {ti •tY•FM°�.�,;,;..at;�-.;'ti:. 'a:.:s+r,°`•a�,rx•`."•,e _ ±��!•.�h,SY. '~• :ir:•=:>;•r.-�+'y,�.st'•i•,isf•+i:.'.rr)•"iy:`:• -::1:,: Jn�,.Z:i. ,'� t� `.'4�'G `l�...��t�=t`�$�:jptw•Y�-. `.:A`t.V�rti`,l• .i 4ti.,iw.11 ti•,\vt..>)Y ..,t'ci e:r- ��+Y:1:-• ''ti"j+.:� TIGHTLINE ANCHORED WITH TWO, 3 FOOT REBAR LENGTHS OR BOLTS. FLARE END SECTION �j QUARRY SPALL OR ENERGY :t,,.<;:.�.x;, a: V. .� .• ..:.•.�.•�'.-;"��J�,�.-1..•^i^•p•+•��j.1A:. :: DISPERSION DEVICE • •�-'F`�a: ?:.�;`; t! .x _ ,��;=:� s' GRASS-LINED SWALE SHOULD BE A MINIMUM ONE FOOT WIDE AT THE BOTTOM AND ONE FOOT DEEP WITH A MAXIMUM SLOPE OF 5 PERCENT. MINIMUM 4 FEET LEVEL SECTION GEOTEXTILE FABRIC Geotechnical Testing Laboratory Geotechnical Services 10071 ag sl SW .WA W512 FIGURE 3 Q�Qc cervices Phom:(360)75`-"61Z DRAINAGE DETAILS Testing Services F":(360)754 4646 Not to scale "Ph"John",kw P.M IBOX 488 091W WA 98526 RECEIVED JUN o 8 2006 'SELF'A OFf:IC,: 01 4CP Qo e At A- ti (A x H l�l AIR A 40 fv) El 4Ca d> Qj Pc4 , i7:FACE IAL SO-WIDE ROLLS E RING TO ATTACH OWRE Ge o tec h nic al STAPLES FABRIC OR EQUIVALENT I I /' , I 1 1 I Testing (jj boTENrv,L % ; ' IINFILTRATIOAI % /' ��' 5a' /A\LOCATION Laboratory 6 MAX 2'Xr WOOD POSTS,STANDAW OR BURY BOTTOM OF FILTER I / BETTER OR EQUAL ALTERNATI: MATERIAL IN B'X12'TRENCH 1 / f STEEL FENCE POSTS 1 / R� OS r � - FILTER FABRIC 6- (,(J SEPTIC1 // / l' A FABRIC I I~ LCQCAT10N i ' I/ FABRIC OR EQUIVALENT 2'-0- 1 , GROUND SURFACE 5'-0' 1 I PROVIDE 3/f-11?WASHED lO / �l GRAVEL SACIffILL IN TRENCH 17 �/ / r �j AND ON BOTH SIDES OF FILTER FENCE FABRIC ON THE SURFACE 8'MI rxr VA700 POSTS ALT:STEEL FENCE POSTS Geotechnical Services 1 1 j 1 I I FILTER FABRIC FENCE NOTES: QA/QC Services I j / I 1 I 1.FILTER FABRIC SHALL BE PURCHASED IN A CONTINUOUS ROLL CUT TO 1 1 I i 1 1 I 1 THE LENGTH OF THE BARRIER TO AVOID USE OF JOINTS.WHENJOINTb Testing Services ARE NECESSARY,FILTER CLOTH SHALL BE SPLICED TOGETHER ONLY AT 1 1 1 1 I 1 ♦ -__----- ----- - - --- - - A SUPPORT POST H ENA MNIMUM POS54NT H OVERLAP AND SECURELY 1 1 1 1 `♦ _ FASTENED AT BOTH ENDS TO THE POST. POTENTIAL. 1 I ,` 220---- 2.POSTS SHALL BE SPACED A MAXIMUM OF 6 FEET APART AND DRIVEN jINPILTRA I 1 --- -� - SECURELY INTO THE GROUND(MINIMUM OF 30 INCHES), ♦♦` - - ---1 - INCHES DEEP ALONG THE LINE OF POSTS AND UPSLOPE FROM THE BARRIER. li iLOCAnor 1 \ �♦♦ ----------------- --�� 3.ATRENCH SHALL BE EXCAVATED APPRO%IMATELVBINCHES WIDE AN072 10011 Blomberg St SW '�� Olympia,WA 98512 O A /t �♦♦ 4 WHEN STANDARD STRENGTH FILTER FABRIC I6 USED.A WRE MESH Phone:(360)754 4612 `♦, ``� ♦\`` 4 SUPPORT FENCE SHALL BE FASTENED SECURELY TO THE UPSLOPE 510E OF THE POSTS USING HEAVY -0UTY W RE STAPLES AT LEAST 1 INCH 1i , ♦ LONG.THE WIRES OR HOG RINGS.THE WIRE SHALL EXTEND INTO THE Fax:(360)754-4848 I � I A C E S IS ROAD, TRENCH A ABOVE T Of INCHES AND SHALL NOT EXTEND MORE THAN 36 INCHES ABOVE THEE ORIGINAL GROUND SURFACE. -----_- 5.THE STANDARD STRENGTH FILTER FABRIC SINLL BE STAPLED OR VARED i V 1 1 TOTHE FENCE AND 20 INCHES OF FABRIC SMALL BEEXTENDED Date: W/30/2006 INTO THE TRENCH.THE FABRIC SHALL NOT EXTEND MORE THAN 38 Designed by: LL (I ; ; , INCHES ABOVE THE ORIGINAL GROUND SURFACE.FILTER FABRIC SHALL I I I I co ; li 11, NOT BE STAPLED TO THE EXISTING TREES. Drawn by:8.WHEN E%TRASTRENGTMFILTER FABRIC AND CLOSER PO5T SPACING IS Checked by:LLL 1 `� -----_ __ USED,THE WIRE MESH SUPPORT FENCE MAP BE ELIMINATED,IN SUCH 1 U M P FAO U S E \ ---- - ,` A CASE,THE FILTER FABRIC IS STAPLED OR`WIRED DIRECTLY TO THE Dwg#:06-30-06-049 1 1 I A ♦`I 1 POSTS WTH ALL OTHER PROVISIONS OR ABOVE NOTES APPLYING. 1 _ 1 j I ♦`-- Y 1 7.FILTER FABRIC FENCES SHALL NOT BE REMOVED BEFORE THE VPSLOPE o ~_ 1 I 1 I AREA HAS BEEN PERMANENTLY STABILIZED 1 _______---- ` `II 11 1 II 1 1 _ __-_-__ 1 1 I 1 1 _-__ 1 ��__-.-- -- 1 1 1 B.FILTER FABRIC FENCES SMALL BE INSPECTED IMMEDIATELY AFTER EACH I II 1 1 ♦ ; i I RAINFALL AND AT LEAST DAILY DURING PROLONGED RAINFALL.ANY 1 1 __-__- - - ♦♦♦ 1 I REQUIRED REPAIRS SHALL BE MADE IMMEDIATELY. ---- 1, .- 1 I 1 - `. ♦♦ 1 I 1 1 ♦�- I 1 I 1 I I 1 1 -___-_ 1 I 1 1 -___-- 1 I ,♦- ____� ___________ •♦ ♦ GENERAL EROSION CONTROL NOTES. _ - ♦♦♦♦ �, I I 1. EROSION CONTROL MEASURES SHALL BE IN PLACE PRIOR TO THE ♦ I -- --- ♦♦ ♦♦♦ ♦ I i I BEGINNING OF CONSTRUCTION.THE PROJECT ENGINEER AND THE COUNTY 1 _ _ _ ""�---------------2w—_ ♦♦♦ \` ♦` 1 j � Q � SHALL INSPECT AND APPROVE THE INSTALLATION OF 1 -_ - EROSION CONTROL MEASURES PRIOR TO BEGINNING CONSTRUCTION. < NORTH _ ♦♦♦,` I 2.EROSION CONTROL MEASURES ARE NOT LIMITED TO THE ITEMS \ - - ♦` 1 �1 j O SCALE D-40' ON THIS PLAN.THE CONTRACTOR I$RESPONSIBLE FOR THE PROJECT NAME: l^ INSTALLATION AND MAINTAINANCE OF ALL EROSION CONTROL MEASURES. _ `♦`` `` 1 I I I w/ _I' DATUM ASSUMED NObILTATIONOFEXISTIN00RPROPOSEDDRAINAGEFACILRIES STEPHEN JOHNSON SITE _ ___ ___ ,` % 1 1 j 'r SHALL BE ALLOWED.CARE SHALL BE TAKEN TO PREVENT MIGRATION ~ -it� , , 1 I I I•i•• TFHS IS NOT A SURVEY OF SILTS TO OFF SITE PROPERTIES. _r_--- "" �, (n �. 3.THE CONTRACTOR SHALL MAKE DAILY SURVEILLANCE OF ALL EROSION JAMES ISON RESIDENCE _ CONTROL MEASURES AND MAIM ANY NECESSARY REPAIRS ORADDITIONS 451 VICTOR ROAD ♦♦♦♦ ` ,, 1 1 j i �/1 I TO"THE EROSION CONTROL MEASURES,THE CONTRACTOR SHALL PROVIDE 10 20 30 40 ADDITIONALEROS]ON CONTROL MEASURES AS DETERMINED NECESSARY ♦�`` 11 I ; By THE COUNTY INSPECTOR ANCIOR THE PROJECT ENGINEER.FAILURE BELFAIR,WASHINGTON _ --------1$0 I 1 1 1 REQUIREMENTS MAY RETO COMPLY WTH ALL SULT IN CIVIL PENALTIES BEICAL AND STATE EROSION NG EKED PARCEL 122212490041 1 1 I I I AGAINST THE CONTRACTOR AND/OR PROJECT OWNER 4,DURING THE WET SEASON(NOVEMBER TO MARCH)ALL DISTURBED SOILS / I SHALL BE STABILIZED WITHIN 48 HOURS AFTER STOP OF WORK EROSION '/1c1/�µ. C`I I CONTROL MEASURES SHALL INCLUDE.BUT NOT BE LIMITED TO, Re'W'NI N� 1 1 1 I COVERING THE EFFECTED AREA INCLUDING SPOIL PILES WITH PLASTIC SHEETING,STRAW MATTING,JUTE MATTING,STRAW MULCH, 1 1 1 OR WOOD CHIPS.SEEDING OF THE DISTURBED AREAS SHALL TAKE j j 1 i E I 1 PLACE AS WEATHER PERMITS. I I I I II CULVER I 5,ALL SEEDED OR SODDED AREAS SHALL BE CHECKED REGULARLY 1 TO MAKE SURE VEGETATIVE COVERAGE IS COMLETE AREAS SHALL BE I � 1 1 REPAIRED,RESEEDED.AND FERTILIZED AS REQUIRED. 1 1 I I I 6.TRACKING OF SOIL OFFSITE WILL NOT BE ALLOWED. ANY SOIL IS I 1 I I TRACKED ONTO A COUNTY STREET,IT SHALL BE REMOVED VED BY I THE END ! i OF THAT WORKING DAY.ANY FURTHER TRACKING MUD WILL THEN V 1 I I{ I 1 BE PREVENTED By SWEEPING OR WASHING OF THE VEHICLES TIRES I I I j l 1 BEFORE DRIVING ON A COUNTY STREET. I 1 I I 1 -------------`----------------' ____ 7.NO MORE THAN 800 LF OF TRENCH TIME. DOWNSIOPE OF MORE THAN 5 P ERCENF SHALL OPENED AT ONEE TIME. _- � • 1 S.EXUVATEC HA MATERIAL SHALL BE PLACED ON THE UPHILL SIDE OF TRENCHES.� TRENCH ADVERSELY AFFECT DEVICES SHALL BE DISCHARGED IN MANNER THAT WILL --�--_� `" ~ --- -------- � ---� , ` � NOT ADVERSELY AFFECT FLOWING STREAMS DRAINAGE SYSTEMS OR OFFSTTE PROPERTIES. -----_--"-- ------ -- ---------- -- �""'' 10. =ALL STORM SEWER INLETS RECEIVING RUNOFF FROM THE PROTECT DURING SCALE:1 inch 40 feet --`- -------- ,' -- /�"---- CONSTRUCTION SHALL BE PROTECTED SO THAT SEDIMENTIADEN WATER WILLS FILTERED BEFORE ENTERING THE CONVEYANCE SYSTEM. �O 11.ALL BE IPR PROTECTED FROM R SIMMEDIATELY ADJACENT TO THE SITE 1 1 1 ��\ J - _ ALL DI BE AREAS SHALL BE STION. FIGURE 2 1 1 1 V 12,ALL OR REED AREAS SHALL BE SEEDED OR SPSOODEO UPON COMPLETIONTHAT 1 L 1 1 -- OF WORK.THE CONTRACTOR SHALL BE RESPONSIBLE O ENSURE TWAT L I j ` f �, - ------ COMPLETE COVERAGE ATHE DISTURBED AREAS IS PRONDEDBTHAT 1 I 11 V , ---- GROWTH OF THE VEGETATION IS ESTABLISHED. 1 13. SITE PLAN -- CATCH BASINS SMALL TRAP SEDIMENT OR FILTER FABRIC MUST BE j , \---- '' PLACED UNDER GRATE UNTIL VEGETATION IS ESTABLISHED. It