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16115 75TH PL W.PDF1111111111116069 16115 75TH PL W CITY OF EDMONDS. CRITICAL AREAS RECONNAISSANCE REPORT. Site Location: 16115 75th Place West Tax Acct. Number: CRA-2 0 6-01110/01 Determination: Study Required Determination #: CRA-2006-0111 ADnlicant: Janis Hansen Owner: J. Sherman Mills CRITICAL AREAS RECONNAISSANCE REPORT- STUDY REQUIRED (CRA-2006-0111) During review and inspection of the subject site, it was found that the site may contain or be n Ero ' hard Area, pursuant to Chapter 23.40 of the adjacent to critical areas, including a Edmonds Community Development Code (ECDC). The LIDAR map (attached) indicates erosion potential, as the site slopes down from east to west at an approximate 19% slope. Because this slope exceeds 15% and because of,the Soil Survey mapped soil types of #3 and #4 (Alderwood , gravelly sandy loam and Alderwood;Everett rg avelly sjdy Leaf ) this site qualifies as an erosion hazard critical area. There is a narrow man-made cement -lined channel on the property that appears to be a waterfall water faat�,ra. It flows' from east to west down the slope of the property. This drainage channel does not meet the definition of stream pursuant to ECDC: 23.40.320 and is therefore not considered a critical area. This site is also located within the designated Earth Subsidence Landslide Hazar , so if there are any known proposed development plans for this site, the applicant should first contact the Building Official at 425.771.0220 for information on the building permit process for properties. located in this area. GENERAL CRITICAL AREAS REPORT REQUIREMENTS Critical Areas Reports identify, classify and delineate any areas on or adjacent to the subject property that may qualify as critical areas. They also assess these areas and identify any potential impacts resulting from your specific development proposal. If a specific development proposal results in an alteration to a critical area the critical areas reportwill. also -contain a mitigation plan. You have the option of completing the portion of the study that classifies and delineates the critical areas and waiting until you have a specific development proposal'to complete the study. You may` also choose submit the entire study with your specific development application. • Please review the minimum report requirements for all -types of Critical Areas which are listed in ECDC 23.40.090.D. There are additional report requirements for different types of critical areas (see .below). • Note that it is important for the report to be prepared by a qt atified_pmfessuuwL3s defined in the ordinance. There are options on how to complete a critical areas study and'an approved list of consultants that you may choose from'. You may contact the Planning Division for more information. • General Mitigation Requirements for all Critical Areas are discussed in ECDC 23.40.110 through 23.40.140. ` 0.,q e a f C42- 3 STUDY REQUIREMENT - EROSION HAZARD AREA It appears that this property contains or is adjacent to an Erosion Hazard Area. • Erosion Hazard areas include Alderwood and Everett series soils on slopes of 15 p greater, among others. • Landslide Hazard Areas are further defined in ECDC 23.80.020.A. • In addition to the general requirements.for Critical Areas, reports referenced. above;; Critical Area report requirements for Erosion Hazard Areas (which are one.of the ; Geologically Hazardous Areas) are provided in ECDC 23.80.050. • Note that Stable Erosion Hazard Areas may have limited report requirements at t' erector's discretion. At a minimum an erosion and sediment control plan prepare compliance with the` -requirements in ECDC Chapter 18.30 shall be required. DEVELOPMENT PROPOSALS ASSOCIATED WITH EROSION HAZARD AREAS Development is restricted within an Erosion Hazard Area and must meet additional c • For erosion hazard areas with suitable slope stability, an erosion and sediment conV61fl ' prepared incompliance ECDC 18.30 will be considered to meet the Critical Areas "S di Required" determination. The determination of "suitable slope stability will be made,b k the Planning and Engineering divisions of the City of Edmonds. '" • In areas where the slope stability is not suitable, projects within Erosion Hazard ArewJ require a report by a licensed Geotechnical Engineer or other qualified professional. ;F • Note that it is important_ for the report to be prepared by a qualified professional as definE the ordinance. • Report requirements are given in-ECDC. 23.80.0.50, and more generally in ECDC y 23.40.090.D • Development standards are.given in ECDC 23.80.060 and 23.80.070. u+ a ALLOWED ACTIVITIES #y,€ Certain ,activities are allowed in or near critical area buffers as specified in ECDC 23.40.20. If you have any questions about whether your proposed development qualifies as an allowed 4„ activity, please contact a Planner for more information. 4 EXEMPT DEVELOPMENT PROPOSALS Certain development proposals may be exempt from Critical Areas Requirements (ECDC :,1: "•�y 23.40.230). If you think that a specific development proposal. may be exempt, contact a Planner J7Al for more information. Gina Coccia, Planner Au -gust 14 2006 Name, Title Signature Date .. NOTE: Cited sections of the Edmonds Community Development Code (ECDC) can be found on the City of Edmonds website at www.ci.edmonds.wa.us. -2- GEOSPECTRUM CONSULTANTS, INC. Ceotechnical Engineering and Earth Sciences November 12, 2012 Thomas and Monica McDonough 16115 75th Place West Edmonds, WA 98026 NOV 21 2�12 DEVELOPMENT �ERVICES SUBJECT:. HAZARD IDENTIFICATION AND MITIGATION STATEMENTS Proposed Garage 16115 75th Place West Edmonds, Washington Project No. 12-130-01 S KET FILE Dear Thomas and Monica, This letter confirms that we have provided geotechnical review of the proposed garage plans, presents our statements of geotechnical risk and mitigation of risk as required by the City of Edmonds and includes updated recommendations for shallow foundations. Geotechnical Review - Proposed Garage Plans This is to confirm that we have provided geotechnical review of the TESC plan dated 10-25-12, prepared by Donna L. Breske, PE, as well as the structural plan Sheets S1, S2 and S3 dated 11/9/12, prepared by Sound Structural Solutions and the geotechnical design assumptions by Sound Structural Solutions and find them to be in conformance with the geotechnical recommendations presented in our report dated August 28, 2012 and our updated shallow foundation recommendations presented in this letter. Minimized Risk Statement We have prepared geotechnical recommendations for design and construction as presented in our report dated 8/28/12 and in this letter. Provided that the conditions and recommendations of our report are satisfied in construction and use, in our opinion the risk of damage to the proposed development, or to adjacent properties, from soil instability will be minimized subject to the conditions set forth in our report and the proposed development and will not increase the potential for soil movement. P.O. Box276, Issaquah, WA 98027-0276 • Phone. (425) 391-4228 Fax: (425) 391.4228 McDonough Risk Probability Statement November 12, 2012 The previous reports prepared for the city which were referenced in our geotechnical evaluation report indicate that all sites within the ESLHA have risk of being affected by future slide movement and that the risk is estimated to range from less than 10 percent probability in 25 years up to about 30 percent probability in 25 years. In our opinion the site lies within risk zone B as defined by the 2007 Landau report which includes the majority of the North Edmonds ESLHA. Hazards within this zone include localized small scale failures of weakened soils as well as ground movements and displacements resulting from .large scale slide movements. Considering the information presented in the ESLHA reports and our observations of the site conditions, in our judgment the probability of earth movement on or adjacent to the site within a 25 year period is estimated to be in the range of about 20 to 30 percent. Risk Mitigation Statements Due to the large size of the ancient landslide masses, it is not practical or feasible for an individual property owner to mitigate the landslide risk by stabilizing the ancient slide. In our opinion, the only reasonable method of mitigation against the risk of future movements is by providing a sufficiently stiff foundation system adequate to withstand differential displacements of the subgrade and minimize distress to the structure in the event of slide movements. Mitigation measures recommended in our referenced report included that the foundation system should be designed to be capable of withstanding differential subgrade offsets that would result in loss of support under a portion of the structure footprint. It was also recommended that flexible utility connections be provided. The onsite slope is also considered to have a moderate potential for future shallow failures. Mitigation of the risk from onsite shallow slope failures was provided by our recommended minimum horizontal setback of foundations from the face of the existing slope below the site. In addition, we noted mitigation measures included in Table 1 of the 2007 Landau Associates report and included them in our report: o New fill should be minimized. We recommended that no new fill be placed on the existing western slope and permanent new fills in the garage site be limited to less than 1 foot above existing grades. o All discharge from roofs and area drains must be tightlined to the storm drain system and no onsite storm water infiltration is allowed. o No permanent irrigation systems are allowed. o Swimming pools are prohibited and hot tubs are restricted. Project No. 12-130-01 Page 2 McDonough November 12, 2012 You should note that even with a properly designed stiff foundation system there could be some structural damage and portions of the structure may require repairs following a slide re -activation event, however the proposed garage is not an occupied structure and therefore the risk of personal injury is low and the risk would be primarily that of structural damage and loss of value. Our evaluation of the risk of slide debris impacting the site from shallow slides originating on the steep slopes above your property (100 to 300 feet east) concluded that the risk is low to very low and therefore in our opinion mitigation against debris impact from shallow slope failures above the garage site is not warranted. Updated Shallow Foundation Recommendations The updated shallow foundation recommendations presented below supersede the shallow foundation recommendations included in our 8128112 report. Properly designed shallow foundation systems consisting of spread footings with stiff grade beams or a stiff continuous mat foundation with low bearing pressure (500 psf) are considered feasible foundation systems that could control static settlements and minimize structure distortions due to differential subgrade offsets across the site (from landslide movements). It should be noted however that even a properly designed stiff foundation system cannot prevent all structure displacements and damage resulting from subgrade offsets under the site. All foundation systems should be designed by a qualified licensed structural engineer. Due to the potential for landslide movements at the site, the foundation system should be designed to be capable of supporting the structure with differential subgrade offsets that would result in loss of support under portions of the structure footprint. Two separate undermined conditions should be considered in structural design: 1) subgrade offsets undermining 1/4 of the structure in the north -south (longitudinal) direction and 2) subgrade offsets undermining 1/3 of the structure in the east -west (transverse) direction along the west side. When designing for the recommended subgrade offset conditions the maximum foundation bearing pressures should not exceed 1500 psf. The subgrade modulus equation in this section may be used to estimate differential vertical displacements across the bearing portion of the foundation. Shallow foundations should have a minimum width and depth of 18 inches and should be.supported on undisturbed medium dense to dense natural bearing soils or on a zone of compacted structural fill. If loose or otherwise unsuitable soils are exposed at minimum footing depth, the footing excavation should be deepened as required to expose suitable bearing soils or the footing should be supported on a zone of structural fill or on a lean mix monolith extending down to deep bearing soils. Foundations adjacent to the existing western slope should also be deepened as required to provide a horizontal setback of at least 8 feet or two footing widths (whichever is greater) from the existing slope surface. Project No. 12-130-01 Page 3 McDonough November 12, 2012 A structural fill zone for foundation support should be constructed using imported select sand and gravel materials with less than 5 percent fines and should be compacted to at least 90 percent of the maximum dry density as determined by the ASTM D1557 test method in accordance with our recommendations for structural fill placement. The zone of compacted structural fill should extend vertically to at least 2 feet below the base of the foundation (base of structural footing) and should extend horizontally, beyond the footing edge at least 2 feet or a distance equal to the structural fill zone thickness (whichever is greater). Greater excavation and replacement will improve general foundation performance and reduce potential static differential settlements. The structural fill should be placed and compacted in accordance with the recommendations presented under "Site Grading" in our 8/28/1.2 report. In areas where spread footings need to be significantly deepened to penetrate unsuitable soils or to satisfy the required western slope setback, foundation loads may be transferred from the recommended minimum foundation depths to the recommended bearing soils or required setback depth by a monolith of lean concrete constructed by excavating trenches along the foundation lines (with a smooth edge bucket) and backfilling with lean concrete having a minimum compressive strength of 1000 psi up to normal minimum footing depths. The width of an un-reinforced lean concrete monolith should be at least as wide as the footing or at least one-third of the monolith height, whichever is greater. Typically the practical depth limit for construction of lean concrete monoliths for foundation support is about 6 to 8 feet for stable soils without seepage. However in areas of soft, wet soils lean mix monolith construction may not be practical due to the high potential for caving of the trench walls. No personnel should enter the lean concrete trenches especially in wet soil areas due to the potential for side wall caving. Estimated static settlements of foundations supported on undisturbed medium dense to dense natural soils or on a properly constructed structural fill zone with static (non - seismic) loading may be based on a Coefficient of Vertical Subgrade Reaction Ks as defined below: Where: Ks = K2 - (DK) (B-2) Ks = pounds per cubic foot (for B = 2 ft to 4ft) . K2 = 18,000 pcf DK = 4,200 pcf B = footing width or effective mat width, feet (2 ft min) Vertical deflection of the subgrade may be estimated by: Dv = Q Ks Project No. 12-130-01 Page 4 McDonough Where: Dv a vertical displacement, feet Q = foundation bearing pressure, psf November 12, 2012 For lateral design, resistance to lateral loads can be assumed to be provided by friction acting at the base of the foundation and by passive earth pressure on the sides of the foundation. A coefficient of friction of 0.3 may be assumed with the dead load forces in contact with onsite soils or structural fill. An allowable static passive earth pressure of 150 psf per foot of depth may be used for the sides of foundations poured against existing soils. Allowable lateral passive pressures may be increased by 33% for wind and seismic forces. CLOSURE This letter was prepared for specific application to this project and for the exclusive use of Thomas and Monica McDonough and their representatives. The findings and conclusions of this report were prepared with the skill and care ordinarily exercised by members of the local geotechnical profession currently practicing under similar conditions. We make no other warranty, either express or implied. Variations may exist in site conditions between those described in this report and actual conditions encountered during construction. If conditions encountered during construction appear to be different from those indicated in this report, our office should be notified. Sincerely, GEOSPECTRUM CONSULTANTS, INC. James A. Doolittle Principal Engineer dist: 1/Addressee (via email) 2/Rob Michel Project No. 12-130-01 Page 5 E'Sz-1, ' k August Thomas and Monica McDonough 16115 75th Place West Edmonds, WA 98026 SUBJECT: GEOTECHNICAL EVALUATION Proposed Garage 16115 75t" Place West Edmonds, Washington Project No. 12-130-01 Dear Thomas and Monica, RECEIVED DEC 0 5 2012 DEVELOPMENT SERVICES COUNTER This report presents_ the results of our geotechnical evaluation of your proposed garage site. Our work was performed in accordance with the scope and conditions of our proposal dated July 27, 2012. The purpose of our work was to evaluate the site and provide recommendations for foundation construction within the North Edmonds Earth Subsidence and Landslide Hazard Area (ESLHA) a hazard area that affects your property. Your builder, Rob Michel has provided us with a current topographic map of the property and the approximate garage footprint location which we used as a references for our evaluations. Review of the site plan indicates that the proposed garage will be located within the upper southeastern corner of the lot adjacent to 74t" Place West. No detailed plans for the garage were provided but based on discussions with Rob Michel we understand that the garage floor will be at approximately the existing pavement grade or about elevation 84 to 85. For the purpose of our evaluation we have assumed that maximum bearing wall loads will be about 1 to 2 kip ff# or less. If actual structural loads exceed this estimate our office should be notified. P.O. Box 276, Issaquah, WA 98027-0276 • Phone: (425) 391-4228 FczK.- (425) 397-4228 McDonough . SCOPE OF WORK August 28, 2012 Our geotechnical .reconnaissance included site reconnaissance, site explorations, review of data,. engineering analyses and evaluations and the preparation of this report. The scope of work included the following specific tasks: o Reviewed geologic mapping and reports prepared for Edmonds by Dames and Moore (1968), Roger . Lowe Associates (1979) and Landau Associates (2007) regarding the existing landslide(s) in the site area. o Performed a site reconnaissance to observe conditions on the site. o Site explorations were performed via trackhoe dug test pits. Two test pits were excavated at locations outside of existing pavement around the proposed building site (see Figure 3). The depths of the explorations ranged from about 6 to10+ feet. o Performed engineering evaluations of the surface and subsurface conditions observed. o Evaluated the existing landslide and the potential for future movement of the considering potential triggering mechanisms. o Evaluated possible landslide hazard mitigation measures. o Prepared this geotechnical report summarizing our findings and recommendations for site development. DATA REVIEW & RESEARCH Geologic Mapping The geologic mapping of Figure 1 indicates the site is located within landslide deposits (Qls) which are about 3200 feet wide and extend from the very steep head scarp slope about 300 feet east of the site down to the shoreline in the site area. The mapping indicates soils exposed in the head scarp slope include the silt and clay interglacial deposits of the Whidbey Formation,. (Qw) in the lower scarp below about elevation 225 and Esperance Sand (Qe) that was deposited ahead of the last glacial advance into the Puget Sound area, approximately 13,000 to 15,000 years ago. Project No. 12-130-01 Page 2 McDonough Previous Studies in the Site Area August 28, 2012 As we have indicated, the site lies within the North Edmonds Earth Subsidence and Landslide Hazard Area (ESLHA) which includes a large (about 3200 feet in width) ancient landslide and areas within the ancient landslide that have been reported to be historically active. There .have been several studies regarding stability issues in this area performed by geotechnical consultants for the City of Edmonds over a period of several decades documenting the ancient landslide limits as well as historic movements dating from 1947. We have reviewed a report by Dames and Moore dated September 23, 1968, a report by Roger Lowe Associates dated October 16, 1979 and a more recent report by Landau Associates dated March 14, 2007. The following present a brief summary of some of the relevant information in those previous reports: Dames and Moore Report,.1968 This earliest report included an discussion of the geologic history as well as a description of know historic episodes of slide movement in the site area. The report included a site vicinity map showing the approximate locations of major historic slides including one that occurred in 1947 and two that occurred in 1955-56. The 1947 slide occurred near your site affecting.an an area extending from about 162"d Street SW southward about 800 feet and extending from the shoreline inland to about 100+ feet upslope of 75th Place West. The 1955-56 slides affected an area ranging from approximately 500 to 1900 feet north .of your site and extending inland about 300 to 400+ feet. Based on the map included in the report, none of the historic slides directly affected or involved your property but the slide. limits indicated are within about 300 to 600 feet from your proposed garage site. Roger Lowe Associates Report, 1979 This report included subsurface explorations and an extensive discussion of the regional geology as well as the site area geology, landslide history and hydrology. They concluded that the original ancient slide is about 3200. feet wide and likely initially occurred within the. past 7000 years. The slide affected soils. (slide debris) are indicated to extend to depths of 20: to 50 feet below the surface in the slide area. They concluded that active historic slide movements generally had occurred within a zone extending inland (easterly) . approximately 400 feet from the Burlington Northern Railroad tracks, a zone that includes your property. This report also documented two new historic landslide. movement areas that occurred in 1973-74. These included a southern area slide that, was about 425 feet wide, centered about 350 feet north of the Laebugten (currently Meadowdale) wharf and extended eastward to about 80 feet east of 75th Avenue West (currently 76.th Place West) as well as a northern slide centered. about 1200 feet north of the wharf and 200 Project No. 12-130-01 Page 3 McDonough August 28, 2012 feet east of the railroad tracks. Based on the.description provided, it appears that the 1973-74 southern slide was only about 300 feet.northwest of the garage site. The Lowe report concluded that the stability of the general landslide area was very sensitive to ground water levels and indicated that ground water levels could be reduced by a system of sewers, storm drains and subsurface drains but that even with drainage improvements, movements of the slide area would likely occur for a period of decades. Landau Associates. Report, 2007 This latest report summarized the previous reports and provided a brief description of site area geology and landslide history. They reported that drainage improvements were made to the site area in 1984 and that the risk of large scale slide movements have been substantially reduced and that no major movements have occurred since. The report indicates that sites within the ESLHA still have a substantial risk of being affected by future slide movement and indicates that the risk has been estimated to range from less than 10 percent probability in 25 years up to about 30 percent probability in 25 years. Figure 1 of the Landau report indicates that your property lies within risk zone B which includes the majority of the North Edmonds ESLHA. Hazards within this zone include localized small scale failures of weakened soils as well as ground movements and displacements resulting from large scale slide movements. LOCAL SITE CONDITIONS Our observations of the site were made on 8/7/12. The property is located within the ancient landslide limits in north Edmonds as approximately shown on Figure 1. The property is located between 75th Place West on the west side and 74th Place West on the east side and the proposed. garage site is at the southeast corner of the property adjacent to 74th Place West. The local site area topography is approximately represented on the maps of Figures 1 and 2 and topography of the site is shown on Figure 3 and a generalized site section is presented on Figure 4. Topography in the site area includes a generally flat lying area at the east side of your property and within the 74th Place West ROW at about elevation 85 which is located within a moderately steep slope extending down to the west and up to the east. Based on the topography of Figure 2 the slope to the east rises about 20 feet at gradients averaging about 25 percent to the toe of a steep (50 percent) slope that is about 35 feet in height extending to about elevation 140 (this appears to be a secondary scarp slope within the ancient landslide).. The toe of the very steep (near 100 percent) primary slide scarp slope of the ancient landslide lies about 300 feet east of the site at about elevation 120 to 160 (see Figure 2). The primary slide scarp slope extends up about Project No. 12-130-01 Page 4 McDonough August 28, 2012 120 to 140+ feet to about elevation 240 to 300 at gradients of about 85 to 90 percent. Areas above both the primaryand secondary scarps generally have gentle gradients. Topography on your property is approximately represented in Figures 3 and 4 and includes the relatively.. flat asphalt paved area at the east side of your property adjacent to 74th Place West and a moderately steep west facing slope which drops down about 12 feet to a gentle slope that extends down to 75th Place West on the lower side of the property. The proposed garage site at the southeast corner of the property will be within the flat pavement area. Based on the topography of Figure 3, the slope gradients within your property range from about 12 percent up to about 25 percent. The onsite slopes drop_ down a total of about 18 to 20 feet to the 75th Place West ROW at the west side of your property. The slope below 75th Place West drops down an additional 45+ feet to the railroad ROW at moderate to steep gradients. We did not observe any evidence of current landslide activity such as ground cracks or fresh slide scarps or scars on or near the property or on the slopes adjacent to the site. The building site area was paved and the adjacent slopes were generally well vegetated. The vegetation on your property_ included lawn grass, shrubs and ornamental trees. Vegetation on the. slope above the site included a landscaped residential development with natural vegetation areas and mature fir trees to the northeast. Subsoils Shallow subsoils were explored with two test pits excavated at the approximate locations shown in Figure, 3. Logs of the test pits are presented in Appendix A. Soils observed in the test pits included about 1 to 1.5 feet of fill which included decayed wood, rebar, plastic and sawdust at the TP-1 location. The underlying soils were generally classified as silt or sandy silt and were generally loose.. Notable exceptions were a dense sand strata encountered at about 5 feet in TP-1 and a thin layer of very hard siltstone-like material encountered at about 5 feet in TP-2. Ground Water No ground water was observed in TP-1 but water was encountered in TP-2 at a depth of about 5.5 feet. Soils above the water table were classified as moist to very moist with measured moisture contents ranging from about 13 to 46 percent of dry weight. No seeps or springs were observed on the general site although we expect that ground water is. near the surface in. the. low& western area of the property as approximately depicted in Figure 4. Project No. 12-130-01 Page 5 McDonough SITE EVALUATIONS Large Ancient Landslide Hazard August 28, 2012 Based on our review.of the geologic mapping (see Figure 1), topographic mapping (see Figures 1 and 2) and the referenced reports, combined with our own observations of the site conditions and the site area topography, it is our opinion that the site is located within the limits of an existing very large, deep seated ancient landslide (Qls) as shown on Figure 1. The results of our explorations indicated loose and eclectic soils as would be expected within deformed and disturbed landslide debris deposits and .the soils encountered are considered consistent with the geologic mapping. Your property is situated in the southern half of the ancient slide area that has been mapped to extend from the south end of 75th Place West to the northern boundary of Edmonds. The City of Edmonds has included your property within the North Edmonds Earth Subsidence and Landslide Hazard Area (ESLHA). Sites within the ESLHA are considered.to have a'substantial risk of being affected by future slide movement and therefore we caution you about the risk of development in this area due to the potential for property damage and loss of value. We understand that the City has allowed development in this area but they require considerations in the development design to help mitigate the effects of potential future movements of the existing landslides. The referenced reports which we reviewed indicate that sites within the ESLHA have risk of being affected by future slide movement that has been estimated to range from less than. 10 percent probability in 25 years up to about 30 percent probability in 25 years. In our opinion. your property lies within risk zone B as defined by the 2007 Landau report which includes the majority . of the North Edmonds ESLHA. Hazards within this zone include localized small scale failures of weakened soils as well as ground movements and displacements resulting from large scale slide movements. Our observations of the site revealed no evidence of current landslide movement, i.e., fresh scarps. or scars or ground cracks and we understand that drainage systems for the general landslide area have been in place since about 1984 to reduce ground water recharge and remove subsurface water to increase the stability of the general landslide. However the referenced. reports reviewed document historic. sliding episodes. affecting large areas near your site located both to. the north and south of your'property and all of the City's consultants have indicated the landslide to be active with a substantial risk of future movement. In addition we noted that the referenced reports did not discuss or consider strong earthquake shaking as. a potential triggering event for future slide' movements. Earthquake shaking would temporarily add inertial loads to the slide mass which could exceed the available strength (depending upon ground water levels and the intensity of the shaking) and result in slide movements. We estimate that the 2001 Nisqually earthquake likely caused a peak site acceleration .of about 0.06g in the site area based on regional recorded peak ground accelerations documented by the University of Project No. 12-130-01 Page 6 McDonough August 28, 2012 Washington and is the only event for which we can infer that the slide mass apparently remained stable (no reports of 2/28/01 .slide movements in the 2007 Landau report). However, the 2009 IBC seismic criteria indicates that the tectonic environment of Puget Sound is capable of generating peak ground accelerations of 0.33g at the site (see Seismic Considerations), a level more than 5 times higher than the estimated shaking level caused by the Nisqually earthquake. Consideringthe reported marginal static stability of the ancient landslide, in our opinion earthquake ground motion levels approaching the IBC design criteria levels would very likely trigger new landslide movements. Considering all of the above, it is our opinion that the risk that your property may be affected by future slide movement should be considered at the high end of the estimated range which is about 30 percent probability in 25 years. In our opinion slide displacements at the site resulting from increased ground water levels and/or seismic ground shaking could range from a few inches to several feet. In our opinion we feel it is reasonable and conservative to assume for design that there will be landslide related differential movements of the site on the order of inches to feet during the life of the structure. Local Stability Hazards We understand that your. proposed garage would be sited within the upper flat lying area at the southeastern corner of the site as shown in Figures 3 and 4. The proposed site is adjacent to the moderate to gentle west facing slope within your property. We performed stability analyses of the slope section shown in Figure 4 considering the conservative ground water assumption and conservative soil strength parameters. The results of our analyses indicate adequate stability (Safety Factor exceeding 1.5) for static conditions. We also evaluated the potential for debris impact from shallow slides initiating on the steeper and higher slopes east of 74th Place West. Considering that the nearest steep slope above the site is located about 100 feet east of the site and that an existing residence is located at the toe of that slope, the risk of slide debris impacting the site from a shallow slide on that steep slope is considered low and the risk from slides originating on the very steep primary slide scarp slope which is more than 300 feet east of the site is considered very low. Landslide Hazards Mitigation Due to the large size of the ancient. la ndslide mass, it is .not practical or feasible for an individual property owner to mitigate the landslide risk by stabilizing the slide. You must be willing to accept the risk that the proposed garage may be damaged by future movements of the existing ancient landslide. It must be assumed for design that future slide movements may occur.during the life of the structure and that movements may result in differential displacements of the site. In our opinion, the only reasonable Project No. 12-130-01 Page 7 McDonough August 28, 2012 method of mitigation against the risk of future movements is by providing a sufficiently stiff foundation system adequate to withstand differential displacements of the subgrade and minimize distress to the structure. In our opinion the foundation system should be designed to be capable of withstanding differential subgrade offsets that would result in loss of support under a portion of the structure footprint. The differential subgrade offsets should be assumed to undermine 1/4 of the structure in the north -south (longitudinal) direction and 1/3 of the structure in the east -west (transverse) direction. Flexible utility connections should be included in the design as well. We note that the proposed garage is not an occupied structure and therefore the risk of personal injury is low and the highest risk would be primarily that of structural damage and loss of value: Even with a properly designed stiff foundation system there could be some structural damage and the structure may require re -leveling following a slide re -activation event. The structure itself should also be properly designed to withstand the effects of sustained tilting of the foundation resulting from subgrade offsets. Specific recommendations for foundation design are presented later in this report. Although our analyses indicated adequate stability for a rotational failure of the local slope on your property, we consider your slope to have a moderate potential for future shallow failures and therefore we recommend that foundations for the proposed garage should be deepened as required to provide a minimum 8 foot horizontal, setback from the face of the existing slope below the site. Our evaluation of the risk of slide debris impacting the site from shallow slides originating on the steep slopes above your. property (100 to 300 feet east) concluded that the risk is low to very low and therefore in our opinion mitigation against debris impact from shallow slope failures above the garage site is not warranted. In addition, as indicated in Table 1 of the. 2007 Landau Associates report: o New fill should be minimized. We recommend that no new fill be placed on the existing western slope and new fills in the garage site be limited to less than 1 foot above existing grades. o All discharge from, roofs and area drains system. " o No storm water infiltration is allowed o No permanent irrigation systems are allowed. must be tightlined to the storm drain o Swimming pools are prohibited and hot tubs are restricted. Project No. 12-130-01 Page 8 McDonough August 28, 2012 Structure Support Options The structure support system must be capable of spanning potential subgrade offsets due to landslide movements as well as control static settlements. The shallow soils encountered in our explorations were generally loose and compressible. Our analyses indicate that conventional spread footing foundations with normal bearing pressures would have unacceptably high static settlements under the expected design loads. Foundation system options to span potential subgrade offsets and control static foundation settlements include the following: o grade beams on spread footings with low bearing pressure: Our analyses indicate that a spread footing foundation bearing pressure of 500 psf could limit foundation settlements to about 1/3. to 2/3 inch for the expected wall load range. Stiff grade beams above the footings would be required to span potential subgrade offsets. Along the west side of the structure adjacent to the existing slope, footings could be extended down using lean concrete monoliths as necessary to satisfy recommended foundation -slope setback. o mat foundation: This would be a continuous stiff concrete mat (slab) extending under the entire building footprint. As with spread footings, the mat must be designed to span potential subgrade offsets. Again, along the. west side of the structure adjacent to the existing slope, bearing could be extended down using lean concrete monoliths to satisfy our recommended foundation -slope setback. o driven pile foundations: Static settlements could be minimized by driven pile foundations however stiff grade beams would still be required to span potential subgrade offsets. The Roger Lowe report reviewed included deep borings near Meadowdale Road and two of the borings were at about the same elevation as the garage site. Those borings indicated about 30 to 40 feet of slide debris overlying hard Whidbey Formation clay. Therefore we expect that pile foundations might extend to depths of 40 to 50 feet before achieving adequate resistance. Your final selection of a foundation system should be based on consideration of damage risk versus cost: Erosion.Hazard Assessment Based on our explorations and observations the surface soils the onsite soils are predominately silt/sand. soils and are considered to have a moderate to high erosion potential when exposed in un-vegetated or disturbed slope areas. However, provided that our recommendations for surface water control are followed and areas disturbed by construction are planted as soon as possible recommendations for erosion control during and after construction, in our opinion the erosion hazard will be mitigated. Project No. 12-130-01 Page 9 McDonough Seismic Considerations August 28, 2012, The Puget Sound region is a seismically active area and you should be aware of the potential for seismic shaking and associated secondary effects. About 17+ moderate to large earthquakes (M5 to M7+) have occurred in the Puget Sound and northern Cascades region since 1872 (140 years) including the 2/28101 M6.8 Nisqually earthquake and it is our opinion that the proposed structure will very likely experience significant ground shaking during its useful life. The site less than 2 miles southwest of the mapped fault zone of the South Whidbey Island fault which has a postulated maximum credible earthquake magnitude of 7.0 to 7.5. The recurrence intervals of large earthquakes on the South Whidbey fault (SWF) is not known but recent data indicates that a earthquake on the order of M6.5 to 7.0 occurred on the SWF about 3000 years ago and smaller events occur more frequently as evidenced by the 5.3 event on May 2, 1996 which was attributed to that fault. Based on a recently published study by the. USGS, the site is also located about 21 miles north of the inferred east -west trending Seattle fault zone which passes through Seattle and trends along the 1-90 corridor. The Seattle fault has a postulated maximum credible. earthquake magnitude on the order of 7.0. The Seattle fault has been documented to have. moved at its west end (Bainbridge Island) about 1000 to 1100 years ago and evidence of movement at the east end has also recently been documented.. Some experts feel that the recurrence interval between large. events on the Seattle Fault may be on the order of several thousands of years but our calculations indicate it may be on the order of 1200 to 1400 years. Another recent study (2004) of the Vashon-Tacoma area presents evidence for the east -west trending .Tacoma Fault which is indicated to pass through the south end of Vashon and the middle of Maury Island about 36 miles south of the site. The study suggests that the Tacoma Fault and the Seattle fault may be linked at depth. In addition to Puget Sound seismic sources, a great earthquake event (M8 to M9+) has been postulated for the Cascadia Subduction. Zone (CSZ) along the northwest Pacific coast of Oregon, Washington. and Canada. The current risk of a future CSZ event is not known at this time. Published reports have indicated recurrence intervals for a CSZ event to range from as little as 100-200 years to as long as 1000+ years and the time of the last event is reported to have been about 312 years ago. The 2009 International Building Code (IBC) adopted by Edmonds requires consideration of a spectral acceleration level with probability of exceedance of 2 percent in 50 years for seismic structural design. This corresponds to about a 2475- year recurrence interval earthquake ground motion. Based on the short period spectral response accelerations presented in Figure 1613.5(1) of the 2009 IBC, adjusted as per equations 16-36, 16-38"and factored as per section 1803.5.12(2), we estimate the IBC peak ground acceleration for soils design at this site to be about 0.33g. Please note that the 0.33g peak ground acceleration includes the additional reduction factor of section Project No. 12-130-01 Page 10 McDonough August 28, 2012 1803.5.12(2) and is not intended for structural analyses. This site is considered a Site Class F for structural design. Considering the presence of the ancient landslide, it is our opinion that the. potential for damage due to seismically induced ground movements, ruptures and offsets is moderate to high depending upon the level of ground motion as discussed above under "Large Ancient Landslide Hazard" evaluation. RECOMMENDATIONS Shallow Foundation Desian Properly designed shallow foundation systems consisting of spread footings with stiff grade beams or a stiff continuous mat foundation with low bearing pressure (500 psf) are considered feasible foundation systems that could control static settlements and minimize structure distortions due to differential subgrade offsets across the site (from landslide movements). It should be noted however that even a properly designed stiff foundation system cannot prevent all structure displacements resulting from subgrade offsets under the site. All foundation systems should be designed by a qualified licensed structural engineer. Due to the potential for landslide. movements at the site, the foundation system should be designed to be capable of supporting the structure with differential subgrade offsets that would result in loss of support under portions of the structure. footprint. The differential subgrade offsets should be assumed to undermine 1/4 of the structure in the north -south (longitudinal) direction and 1/3 of the structure in the east -west (transverse) direction along the west side. When designing for the recommended subgrade offset conditions, bearing pressures may be assumed to vary linearly and the maximum bearing pressure adjacent to the assumed offset location should not exceed 1500 psf. Structure tilt resulting from subgrade offsets should also be considered in design and may be estimated using the .subgrade modulus equation in this section to estimate differential vertical displacements across the bearing portion ofthe foundation which would be additive to the structural deflections of the cantilevered foundation. Foundations adjacent to the existing slope should be deepened as required to provide a horizontal setback of at least 8 feet or two.footing widths (whichever is greater) from the existing slope surface. As an alternative to satisfy the slope setback requirement, foundation loads may be extended to the recommended depth for adequate setback by a monolith of lean concrete having a minimum compressive strength of 1000 psi. The width of an un-reinforced lean concrete monolith should be at least as wide as the footing or at least one-third of the monolith height, whichever is greater. Project No. 12-130-01 Page 11 McDonough August 28, 2012 Shallow foundations should be supported on a zone of compacted structural fill. The structural fill zone should be constructed using imported select sand and gravel materials with less than 5 percent.fines and should be compacted to at least 90 percent of the maximum .dry density as determined by the ASTM D1557 test method in accordance with the recommendations for structural fill placement. The zone of compacted structural fill should extend vertically to at. least 2 feet below the base of the foundation (base of structural ,footing or base of lean concrete monolith) and should extend horizontally beyond the footing edge at least 2 feet or a distance equal to the structural fill zone thickness (whichever is greater). Greater excavation and replacement will improve general foundation performance and reduce .potential static differential settlements. The structural fill should be placed and compacted in accordance with the recommendations presented below under "Site Grading". Estimated settlements of foundations supported on a properly constructed structural fill zone with static (non -slide movement and non -seismic) loading may be based on a Coefficient of Vertical Subgrade Reaction Ks as defined below: Where: Ks = K2 - (DK) (B-2) Ks = pounds per cubic foot (for B = 2 ft to 4ft) K2 = 18,000 pcf DK = 4,200.pcf B = footing width or effective mat width, feet (2 ft min) Vertical deflection of the subgrade maybe estimated by: Where: . Dv = Q Ks Dv = vertical displacement, feet Q= foundation bearing pressure, psf For lateral design, resistance to lateral loads can be assumed to be provided by friction acting at the base of the foundation and by passive earth pressure on the sides of the foundation. A coefficient of friction of 0.3 may be assumed with the dead load forces in contact with onsite soils or structural fill. An allowable static passive earth pressure of 150 psf per foot of depth may be used for the. sides of foundations poured against existing soils. Allowable lateral passive pressures may be increased by 33% for wind and seismic forces. Project No. 12-130-01 Page 12 McDonough Driven Pipe Piles August 28, 2012 Properly constructed pipe piles are considered a feasible alternative foundation system which could transfer foundation loads through the slide affected soils to deep bearing soils. This type of support is constructed by driving 2-inch or 3-inch diameter steel pipe to refusal into the bearing soils below existing unsuitable soils. Depth to bearing soils is unknown but based, on the Lowe report reviewed indicates they may be at depths ranging from about 30 to 40+ feet. Based on our experience, piles typically penetrate about 5 to 15 feet into the bearing soils before encountering refusal. Pile installation should be accomplished with a tractor mounted hydraulic hammer system. Refusal penetration rates for piles will depend on the hammer size and the load testing results. For 3-inch piles a hammer weight in the range of about 650 to 850 pounds should be used. Refusal penetration rate for a 3-inch pile driven with a tractor - mounted 6501b hydraulic hammer typically should be in the range of about 15 to 20 seconds per inch. Refusal penetration rate for a 2-inch pile driven with a tractor - mounted 6501b hydraulic hammer typically should be in the range of about 8 to 10 seconds per inch. An allowable vertical downward capacity of 4 kips (Factor of Safety = 2+) may be assumed for 2-inch diameter piles and capacities of _10 to 15 kips (Factor of Safety = 2+) can generally be achieved for 3-inch diameter piles installed as recommended above but actual allowable downward capacities must be confirmed based on a site specific load test of 3-inch piles for the specific hammer size and refusal criteria. No uplift capacity or lateral support should .be assumed for driven pipe piles. Resistance to lateral loads can be provided by battered piles (compression only) and by passive earth pressure on the sides of the grade beams. An allowable static passive earth pressure of 150 psf per foot of depth may be used for the sides of foundations poured against existing fill soils. Allowable lateral passive pressures may be increased by 33% for wind and seismic forces. A load test on a representative 3-inch pile should be performed prior to production pile installation to verify the appropriate allowable vertical capacity for the 3-inch pile size and refusal criteria. Testing should.be accomplished according to the ASTM quick test procedure described in the ASTM D .1143-81 test method for piles under static axial. compressive load.' Allowable capacity should be based on test pile settlement of 1/4 inch or less for the design load and a Factor of Safety of 2.0+ of ultimate capacity. Capacity may be limited by the structural capacity of the pipe and connections which should be determined by the structural engineer. The pipe which forms the pile, must be of structural quality (schedule 40+) and must be provided with a corrosion resistant coating (galvanized). Couplers should also be galvanized or as a minimum provided with a zinc coating. The pipe pile supports should be capped with a grade beam to transfer structural loads to the piles. The pile/grade beam system should be designed by a qualified structural engineer. Project No. 12-130-01 Page 13 McDonough August 28, 2012 Due to the potential for landslide movements at the site, the pile foundation system should be designed to be. capable of supporting the structure with differential subgrade offsets that would result in loss of support under portions of the structure footprint. The differential subgrade offsets should be assumed to undermine 1/4 of the structure in the north -south (longitudinal) direction and 1/3 of the structure in the east -west (transverse) direction along the west side. When designing for the recommended subgrade offset condition, capacities of the piles above the offset location may be temporarily increased by 50% to support the undermined structure. Structure tilt resulting from subgrade offsets should also be considered in design and may be estimated by a proportional increase in settlements of the piles with increased loads which would be added to the structural deflections of the cantilevered foundation. Site Grading Site grading is expected to consist primarily of excavation and fill placement to prepare subgrade areas. Excavated onsite natural soils free of deleterious material may be used for general structural fill, however moisture contents of the soils encountered in our explorations were above optimum and therefore compaction of the onsite soils may be very difficult except when properly dried. Approved imported sand and gravel should be used for structural fill in foundation support zones. Recommendations for site preparation, temporary excavations, structural fill, slab subgrade preparation and utility trench backfill are presented below. Site Preparation: Existing vegetation, debris, fill and soft or .loose soils should be stripped from the areas that are to be graded. During rough grading, excess soils may be stockpiled for later use. Soils containing more than 1 % by weight of organics may be used in planter areas, but should not be used for fill beneath building or pavement areas. Stumps, debris and trash, plus rocks and rubble over 6 inches in size, should be removed from the grading areas. Subsoil conditions on the site may vary from those encountered in the test pits. Therefore, the soils engineer should observe the prepared areas prior to placement of any new fills. Temporary Excavations: Sloped temporary construction excavations may be used where planned excavation limits will not. undermine structures or interfere with other construction. Where there is not enough room for sloped excavations, shoring should be provided. Sloped temporary excavations may be made vertically to depths less than 3 feet. Deeper temporary excavations that workers will enter should be shored or made at slope gradients no steeper than 1 : 1 (horizontal:vertical), however it should be noted that the contractor is responsible for safety and maintenance of construction slopes. Soils exposed in cut slopes should be kept moist, but not saturated, to retard ravelling and sloughing. Surface drainage should be directed.away from the top edge of cut slopes. Surcharge loads should not be allowed within 5 feet of the top of cut slopes. Project No. 12-130-01 Page 14 McDonough August 28, 20.12 Structural Fill: Excavated onsite soils may be used for general structural fill provided that. moisture conditions can be adequately reduced for compaction. However, approved imported sand and gravel should be used for structural fill in foundation support areas. Imported material. for fill should be clean, well -graded sand and gravel materials free of organic debris and deleterious material with less than 20 percent fines based on the sand fraction. Organics and any existing fill and loose to medium dense soils and debris should be removed from structural fill areas prior to placing structural fill or backfill. Structural fill should be placed in horizontal layers not exceeding 8 inches in loose thickness and compacted to at least 90% of the maximum dry density as determined, by the ASTM D1557 test method. Slab/Pavement Subgrade Preparation: Existing fill, topsoil and loose or disturbed soils should be excavated to expose natural soils at least 12 inches below final subgrade elevation in slab. and pavement subgrade areas and 18 inches below final subgrade elevation in driveway areas. Structural fill should then be. placed to final subgrade. Structural fill should consist of approved onsite.soils or imported well -graded sand and gravel materials free of organic debris and other deleterious material. Subgrade structural fill should have a maximum particle size of 3 inches. . Subgrade structural.fill should be placed in horizontal lifts not exceeding 8 inches in loose thickness and compacted to at least 90% of the maximum dry density as determined by the ASTM D1557 test method. Risk of slab cracking can be reduced by placing 2-way reinforcement steel. If a floor covering is to be used, the slab should be underlain by a polyethylene vapor barrier of at least 6 mil thickness. Utility Trenches: Buried utility conduits should be bedded and backfilled, around the conduit in accordance with the project specifications. Where conduit crosses pavement subgrade areas the backfill above the pipe should be placed and compacted in accordance with the recommendations for structural fill. Drainage Control All drains including roof drains, subsurface drains and surface area drains should be tightlined to the storm drain system. Positive drainage should be provided away from the slopes to prevent any water flow over the slopes and help reduce stability and erosion hazard. A desirable slope for surface drainage is 2% in landscaped areas and 1 % in paved areas. A permanent perimeter drain, independent of the roof drain system, should be placed adjacent to the base of the foundations and or grade beams. The drain should consist Project No. 12-130-01 Page 15 McDonough August 28, 2012 of a four -inch diameter perforated PVC drain pipe placed in at least one cubic foot of drain gravel per lineal foot along the base of the foundations. The drain gravel zone around the pipe should be encapsulated with a membrane of Mirafi 140 filter fabric or equivalent between the drainage zone material and onsite silty soil backfill. In addition if conditions exposed during construction warrant, an interceptor subdrain system may be required to intercept ground water migration from the upslope areas. The subdrain should be placed along the upper side of the developed area but down slope from any surface drainage control berm and should consist of a filter fabric lined trench filled with clean sand or drain rock with a perforated PVC drain pipe at the base. The drain trench should be at least 18" wide, and should penetrate at least one foot into a any impermeable (silt/clay) layer. Six inches of native soil cover should be placed over the drain to reduce surface water infiltration. Discharge from the subdrain should be conducted via tightline to the storm drain system discharge. Control 'of ground water conditions should be completed during excavations for the proposed garage to minimize the ground water seepage occurring during construction. Erosion Control Onsite materials are expected to be erodible when exposed to uncontrolled water flow in slope areas. Soil stockpiles should be covered during heavy rainfall .and siltation fences or other detention devices should be provided around the lower side of graded areas as required to control the transport of eroded material. The lower edge of the silt fence fabric should have "J" shaped embedment in a trench extending at least 12 inches below the ground surface. Surface drainage should be directed away from slopes and exposed soil areas should be planted immediately with grass and deep rooted plants to help reduce erosion potential. Tree cutting should be minimized on the slope areas (outside of the building area). Pruning or trimming of trees with a minimum of disturbance to the existing slope surface and vegetation is preferred as opposed to felling. If felling is required, stumps should be left intact where possible to reduce disturbance to the shallow slope soils. Plan Review This report has been prepared to aid in the evaluation of this site and to assist the owners and their consultants in the design and construction of the proposed development. It is recommended that this office be requested to review the final design drawings and specifications to determine if the recommendations of this report have been properly implemented and to make any supplemental design recommendations which may be required. Project No. 12-130-01 Page 16 McDonough August 28, 2012 Observations and Testing During Construction Recommendations presented in this report are based on the assumption that soil conditions exposed during construction will be observed by our office so that any necessary design changes or supplements may .be made. Subgrade preparation for shallow foundation systems. should be observed by our office to verify our recommended subgrade preparation procedures. Installation and load testing of all driven pipe piles should be observed by our office to confirm allowable capacities and refusal criteria. Drainage control systems should be observed to verify proper construction. Proper fill placement and compaction should- be verified with field and laboratory density testing by a qualified testing laboratory. Drainage and erosion control systems should also be observed to verify proper construction. CLOSURE This report was prepared for specific application to this project and for the exclusive use of Thomas and Monica McDonough and. their representatives. The findings and conclusions of this report were prepared with the skill and care ordinarily exercised by members of the local geotechnical profession currently practicing under similar conditions. We make_ no other warranty, either express or implied. Variations may exist in site conditions between those described in this report and actual conditions encountered during. construction. If conditions . encountered . during construction appear to be different from those indicated in this report, our office should be notified. Respectfully submitted; GEOSPECTRUM CONSULTANTS, INC. James A. Doolittle Principal Engineer Encl: Figures 1,through .4 Appendix A Dist: 1/Addressee..(via email). 2/Rob Michel Project No. 12-130-01 Page 17 mt Modified Land pis Landslide ! pvr Vashon recessional outwash pvt Vashon till pa Esperance Sand ) 1 i ' \t pw Whidbey formation 1 1 .•} �Ir '" i 1 pdb Double Bluff Drift ei ipvt 100 0 100 Yon 300 400 Sq0 (i !' ` ',1 �/y SCALE IN FEET\1', 1 Cantou. Im.rrtrl 5' II 11` '. .I I \\.\ ..7f_ :..� �Y, 9orinp L... Ilan d NumO�r 44 `� •i, I I �, j�J �1 zy. . P Y' �• /ire' j 's � ''z� O� �r ��l��,il �"r' Iri j �i\ • _ �'` \%^��. rye' �" \\\mil/1 4 ll 1 `�• s{ 4 �� /;/ !;c a r ,•-,Uq.�; �..Z—� it �-- !� rl. SP if nw .�l f l}I ..� I ��t•=,ram 1 ,"\—� �f .�," yr ref: Figure 2, Geologic Map, Roger Lowe Associates report,. dated October 16, 1979 reduced scale: 1 "= 500' SITE VICINITY GEOLOGIC MAP Proposed Garage GEOSPECTRUM CONSULTANTS, INC. 16115 75th Place West Ednonds,.Washington Gootachnlcol E-n8/n©ar/n67 and Eorth Sc/ancoa Proj. No.12-130 Date 8/12 Figure 1 a < r ' •�w1:.w� JT t -27 In '�<.. � A / rr 1iS,� "`'r,,,w' '•�a`'�� mow, "�.„� M""' °`;~ } ) t" me»µ CM7 � s �� 3 t R'�rKi, � hl�.y1+'• a • t , T, i Y� t- ' ` .,,.,,-paw-nr OO y> i+Aa"a . �* r l - _• �� we�s+ei.5r-Sa• ._9_,. .",�,r ', '.S ��y gal bff $ _ C""`'=^.! -_ 't' '�'JyF�"K '3 ti "' G f..T pai yr.0 �'f 1«rNiftls \A inww`^��.�' - - u r3y . t 'tom r.t> V - SL o. x•�s' F./ ? / ..Syr"` .,rlti�� .wni�"' ��p,�.w.>�o C-.-`�{ ^`e� R t Z*' . '� t �, '1`'• -'� � r •rl � ¢Y..0%f a ~•r.a+t''�..«nE..,""S._... ..,.. ,;\ ti a y > s t ? r - ('.P t yi __ \ t>w'�r„ >� 7�Aw/. t �" {� �` •• P Qi �yr�t T�a; r`fi"T•a.s�� .. y�.'.�� ""'�,""� __ i : �. �`1X � ', 7hw=� ,. r' < , a''>4 o W W py. �'�i�..,,••¢¢�� yf _.t l s n('Fs' N) %.�Y ,.4< w�Xy,,. '(, - } { -__.. (� •rl ��'1� � 73'�^e..�.t , „�� a .aR'�r / / • 'Y EF / - "� .a s -;� U 4a > ,♦ < -ry�' "'.C"""� Y n kl f' s y. c '__. z"- _ u`sYt�!'F+��!. N3Aar"~s.wu.".,a",7r"M'Mf"ke-Y.api, n. •, '£ l '� � 2 .S t 77 \ a •• �0 ..w,. -- �`" 40 Ly "1 jti �9' '; {�ykys +t, < \t �C,�. ��'tr c 1, 49 W ✓ ./%,x, wt�f'i v °Y"so tyk > LOCAL SITE AREA TOPOGRAPHY Proposed Garage GEOSPECTRUM CONSULTANTS, INC. 16115 75th Place west Ddmnds, Washington GooYBchnlcol EnFjJnoaiing and Ecrth Scloncos Proj. No. 12-130 Date 8/12 Figure 2 J INN ;6 --- M IT W a � / z �. .91 S s Sgd - m N. �� v 8�Lt11k� Os '" i' M ! N N O1 8 co Wr U co, o U N ^ zo z 80 � > N A � O N co A� CU v o"t a h OL cu �c ^ + `�- Q }0�.� �D + . + + Zt Z ca +8a n QL 1!) N V) �D Ct7p 90 Z st N ` DD.ac + SITE DEVELOPMENT AND EXPLORATION PLAD GEOSPECTRUM CONSULTANTS, INC Proposed Garage 11175th Place west Bdmonds,.Washington GaotBchnlco/ EnB/nosi/n® and Earth Sclancos Proj. No.12-130 Date 8/12 Figure 3 1 I M cjo a ..-a ° u M U a, co — W cn Q c o o �.. o . LLJ CV Ico �. II Q co LLJ U J CO 0 Q c/) t LU z � LJ J c ca O X LU MOa 1saM aoeld u152- O O O O O O O C\l O 0) Cp d CV GENERALIZED SITE SECTION GEOSPECTRUM CONSULTANTS, INC. Proposed Garage 16115 75th Place West Edmonds,Washington Gaotachnlco/'En8/noailn8r and E'orfh Scloncos Proj. No.12-130 Date 8/12 Figure 4 APPENDIX A FIELD EXPLORATION Our field exploration included a site reconnaissance and subsurface exploration program. During the site reconnaissance, the surface site conditions were noted, and the locations of the test pits were approximately determined. The test pits were approximately. located using the existing features as a reference. Elevations at the test pits locations were estimated based on the topographic map provided. Test pits were advanced using a Kubota KX121-3 trackhoe. Soils were continuously logged and classified in the field by visual examination, in accordance with the ASTM Soil Classification system. Logs of the test pits are presented on the test pit summary sheet A-1. The test pit summaries include descriptions of the soils and pertinent field data. Soil consistency and moisture conditions indicated on the logs are interpretations based on the conditions observed in the field. Boundaries between soil strata indicated on the logs are approximate and actual transitions between strata may be gradual. TEST PIT NO. 1 Logged by JAD Date: 8/7/12 Elevation: 84' Depth Blows Class. Soil Description Consistency ,Moisture Color W(%) Comments 0 Crushed Gravel loose moist 9 ray FILL OL Topsoil/or a ics & decayed ood wireTar, dark 1 plastic,sawffust to brown very 2 ML Sandy Silt very fine OrRin with occ roots to 2" moist 24.0 3 4 ............................................................... ML Silt with occ roots . ................ row n 41.2 5 SP Sand, fine dense moist gray 13.3 6 Maximum depth 6 feet. No ground water encountered. TEST PIT NO. 2 Logged by JAD Date: 8/7/12 Elevation: 82' Depth Blows Class. Soil Description Consistency ..Moisture Color W(%) Comments 0 2 SM Silty Sand ve fine w/ ravV,rr loose moist to very brn 15.5 FILL brown ML Sandy Silt,, very fine e..-brn 4 ................. moist ML Silt a 42 g 46:1 6 ML Sandy Silt loose wet brown 8 10 12 Maximum depth 10.5 ft. (excavatic n to 5.5 ft ar d probing to 10.5 ft) Ground water at 5.5 ft. 14 GEOSPECTRUM CONSULTANTS, INC. Proposed Garage 16115 75th .Place West Geotechnical Engineering and Earth Sciences Edmonds, Washington Proj. No. 12-130 Date 8/12 Figure A-1 Critical Areas Checklist Site Information (soils/topography/hydrology/vegetation) 1. Site Address/Location: 2. 3. 4. CA File No Ce)�- We ( � Property Tax,Account Number: Approximate Site Size (acres or square feet): 5YY1 a 11 ' I vt Y1 D r i'1r1 Inert d, i v1 W w►MZY 1 Is this site currently developed? 1/yes; no. o wY1 WS Vt t'Q ,50 C.QY15 i dPre4 cuwibi►'led." pursuan-f If yes, how is site developed? DUs . j Ou-r no I W) 1_ tJ6 to FGDL . la-.40. 03a• C_. 5. Describe the general site topography. Check all that apply. Flat: less than 5-feet elevation change over entire site. Rolling. slopes on site generally less than 15% (a vertical rise of 10-feet over a horizontal distance of 66-feet). Hilly: slopes present on site of more than 15% and less than 30% (a vertical rise of 10-feet over a horizontal.distance of 33 to 66-feet). Steep: grades of greater than 30% present on site (a vertical rise of 10-feet over a horizontal distance of less than 33-feet). Other (please describe):. 6. Site contains. areas of year-round standing water: N11L_ ; Approx. Depth: 7. Site contains areas of seasonal standing water: ; Approx. Depth: 1. 2. 3. What season(s) of the year? Site is in the floodway floodplain_ of a water course. Site contains a creek or an area where water flows across the grounds. surface? Flows are .year-round? Flows are seasonal? (What.time of ye ' )• The W afW Site is primarily: forested ; meadow ;shrubs mixed, f'-f,A IUr?� wa 9 urban landscaped (lawn, shrubs etc) i n o pe (,c d &A -A ol0 c4i Obvious wetland is present on site: ADnot Y!r) -jYtf, deA, n i _._ _ 5 +0.3z.0� - GOACi'FAf,,..._ For City Staff Use Only 5 O� ro Plan Check Number, if applicable? t4 o n e, e Site is Zoned? R• S— 2 0. SCS mapped soil type(s)? 'k 3 avid, * 4 ( tltd,-&vvD f) 4. Critical Areas inventory or C.A. map indicates Critical. Area on site? W DAB vnA 1 A A i GA i't y' 19'/ 6710P-C (Vne,iMlnatiard-. 5. Site within designated earth subsidence landslide hazard area? c7 f G 0 VI r6i C_+ +j e, J5u i l d i n_9 Of+ic ial fvY"iAf rMati Q11 reGardirig deVeAVPMf21f nmia os a 15 e ro s 1 cn h a za rd DETERMINATION 191 51ope STUDY REQUIRED WAIVER Reviewed bv: Ci i h a✓ G o GG i a-- Date: D eb 11 1 N 0 0 (D 9- S #P20 `4C. I %9" City. of Edmonds Development Services Department Planning Division Phone: 425.771.0220 Fax: 425.771.0221 The Critical Areas Checklist' contained on this form is to be filled, out. by, "any pei on .preparing a Development Permit Application for the City of Edmonds prior to 'his/l ei submittal: of the application to the City.' The purpose of the Checklist is to enable City staff to determine whether any potential Critical Areas are, or may be, present on the subject property. The information needed to complete. .the Checklist should be easily available from observations of the site or data available at City Hall (Critical areas inventories, maps, or soil surveys). Date Received: City Receipt #: l�E Critical Areas File #: &0-A - 'ho D lP — of 1 Critical Areas Checklist Fee: $135.00 Date Mailed to Applicant: A property owner, or his/her authorized representative, must fill out the checklist, ,sign and date. it, and submit it to the City. The City will review the checklist,.make a precursory' site visit, and make a determination of the subsequent , steps necessary to complete a development permit application. Please submit a vicinity map, along with the signed copy ofthis:form to assist City staff,in finding and locating the specific piece of property described on this forma In addition, .the applicant, shall. include other pertinent information .(e.g. site' plan, .topography map, etc.) or studies in conjunction with'this Checklist to assistant staff' in completing their preliminary assessment of the site. The undersigned applicant, and his/her/its heirs, and assigns, in consideration on -the processing of the application agrees to release, indemnify,, defend and hold the City .of.Edmonds harmless from any and all damages, including reasonable attomey's fees, arising from any, action or, infraction based in ,whole or part upon . false, misleading, inaccurate or incomplete informationTurnished`by the applicant, his/her/its agents or employees. By, my signature, ,I certify that the* information and exhibits herewith submitted are true and correct to the best of my knowledge and thatI am authorized t e s application orpft behalf of the owner as listed. below. , SIGNATURE OF APPLICANT/AGENT ��✓ DATE �� v Property Owner's Authorizatio ,By.. my -,signature; I certify that Ihave authorized the above Applicant/Agent-to applyfor the subject land use application, and,grant:my perms ro for the public officials and the stafl'of the City of Edmonds to enter the subject property. for the purpose of mppecti p dposting atten to this application. T SIGNATURE OF OWNE , Owner/Ap/pUcant: � PAll'/I `' -i //s- Name. j s � S t ddress 11 Le Zl_ 77 City . State Zip Telephone: Email address (optional): DATE. 7 ✓ p/ r 0 6 licant Repres tative: ' S Address City State, ry Zip Telephony' 'lo '� • '/ ` Email Ad eps (optional): ,pa Lhj thser— cjau] ��=r, Cow CITY OF EDMONDS CRITICAL AREAS RECONNAISSANCE REPORT Site Location: 16115 75'h Place West Tax Acct. Number: 00513105800900/01 Determination: Study Required Determination #: CRA-2006-0111 Applicant: Janis Hansen Owner: J. Sherman Mills CRITICAL AREAS RECONNAISSANCE REPORT: STUDY REQUIRED (CRA-2006-0111) During review and inspection of the subject site, it was found that the site may contain or be adjacent to critical areas, including an Erosion Hazard Area, pursuant to Chapter 23.40 of the Edmonds Community Development Code (ECDC). The LIDAR map (attached) indicates erosion potential, as the site slopes down from east to west at an approximate 19% slope. Because this slope exceeds 15% and because of the Soil Survey mapped soil types of #3 and #4 (Alderwood gravelly sandy loam and Alderwood-Everett gravelly sandy loams) this site qualifies as an erosion hazard critical area. There is a narrow man-made cement -lined channel on the property that appears to be a waterfall water feature. It flows from east to west down the slope of the property. This drainage channel does not meet the definition of stream pursuant to ECDC 23.40.320 and is therefore not considered a critical area. This site is also located within the designated Earth Subsidence Landslide Hazard Area, so if there are any known proposed development plans for this site, the applicant should first contact the Building Official at 425.771.0220 for information on the building permit process for properties located in this area. GENERAL CRITICAL AREAS REPORT REQUIREMENTS Critical Areas Reports identify, classify and delineate any areas on or adjacent to the subject property that may qualify as critical areas. They also assess these areas and identify any potential impacts resulting from your specific development proposal. If a specific development proposal results in an alteration to a critical area the critical areas report will also contain a mitigation plan. You have the option of completing the portion of the study that classifies and delineates the critical areas and waiting until you have a specific development proposal to complete the study. You may also choose submit the entire study with your specific development application. • Please review the minimum report requirements for all types of Critical Areas which are listed in ECDC 23.40.090.D. There are additional report requirements for different types of critical areas (see below). • Note that it is important for the report to be prepared by a qualified professional as defined in the ordinance. There are options on how to complete a critical areas study and an approved list of consultants that you may choose from. You may contact the Planning Division for more information. • General Mitigation Requirements for all Critical Areas are discussed in ECDC 23.40.110 through 23.40.140. - 1 - STUDY REQUIREMENT — EROSION HAZARD AREA It appears that this property contains or is adjacent to an Erosion Hazard Area. • Erosion Hazard areas include Alderwood and Everett series soils on slopes of 15 percent or greater, among others. • Landslide Hazard Areas are further defined in ECDC 23.80.020.A. • In addition to the general requirements for Critical Areas reports referenced above, specific Critical Area report requirements for Erosion Hazard Areas (which are one of the Geologically Hazardous Areas) are provided in ECDC 23.80.050. • Note that Stable Erosion Hazard Areas may have limited report requirements at the director's discretion. At a minimum an erosion and sediment control plan prepared in compliance with the requirements in ECDC Chapter 18.30 shall be required. DEVELOPMENT PROPOSALS ASSOCIATED WITH EROSION HAZARD AREAS Development is restricted within an Erosion Hazard Area and must meet additional criteria. • For erosion hazard areas with suitable slope stability, an erosion and sediment control plan prepared in compliance ECDC 18.30 will be considered to meet the Critical Areas "Study Required" determination. The determination of "suitable slope stability" will be made by both the Planning and Engineering divisions of the City of Edmonds. • In areas where the slope stability is not suitable, projects within Erosion Hazard Areas will require a report by a licensed Geotechnical Engineer or other qualified professional. • Note that it is important for the report to be prepared by a qualified professional as defined in the ordinance. • Report requirements are given in ECDC 23.80.050, and more generally in ECDC 23.40.090.D • Development standards are given in ECDC 23.80.060 and 23.80.070. ALLOWED ACTIVITIES Certain activities are allowed in or near critical area buffers as specified in ECDC 23.40.20. If you have any questions about whether your proposed development qualifies as an allowed activity, please contact a Planner for more information. EXEMPT DEVELOPMENT PROPOSALS Certain development proposals may be exempt from Critical Areas Requirements (ECDC 23.40.230). If you think that a specific development proposal may be exempt, contact a Planner for more information. Gina Coccia, Planner GI/l/I/1/'erV LU (if/r/vl�- August 14, 2006 Name, Title Q Signature Date NOTE: Cited sections of the Edmonds Community Development Code (ECDC) can be found on the City of Edmonds website at www.ci.edmonds.wa.us. -2- CITY OF EDMONDS 'PUBLIC WORKS DEPARTMENT SIDE SEWER PERMIT FOR INSPECTION CALL -71-75 Permit �0 Issue Date PERMIT MUST BE POSTED ON JOB SITE =ML� 1. Address' Construction "WAWAMrjMW. �; �r j'�11771 rr : r'i� �.? )"J NWOOD LINE 2.' Property Legal Description (indlude.all easements)/ o¢s 61) /G' P/be/ S-,p Alrac1ca/dales 3. Single Family Residence ,fj Multi -Family No. of Units Commercial 4. Owner and/or Builder _ %' ��- 1�G� a 5. Contractor & License No. 6.. Invasion into City Right -of -Way: No v' Yes (If Yes Right-of- way Construction Permit Required - Call Dial Dig V!4, ,r-/574AA before excavation). 1-800-454-5555 7. Cross other private property: Yes No a- Easement required - attach legal description and county easement number. READ THE FOLLOWING AND SIGN: a. Property owners must obtain a permit to install side sewers on their property. A licensed side sewer contractor must be employed to construct side sewers in the public right-of-way. b. The side sewer contractor assumes full reponsibility for each installation for one year. C. Commercial establishment requires a minimum of a six inch (6") side sewer line. d. Side sewers may not be installed closer than thirty inches (30") to any structure. e. Side sewer lines must be laid at a minimum grade of 2% (1.150) and maximum grade of 100% (450). f. No turn in side sewer greater than 45° (1/8,bend) is0allowed between cleanout. All 90 turns must be constructed of a 45 (1/8 bend) and Wye with removable cap. g. No down spouts, footing drains or floor drains can be connected to side sewer system. h. Pea gravel is required for bedding when installing sewer lines through other than granular soil. i. Cleanouts are required at 30"-60" from each plumbing exit line and at minimum intervals of 100' along sewer line run. j. Trenches within City right-of-way must be restored to original conditions. Contractors shall be responsible for right-of-way failure due to poor compaction of fill. k.. Side sewer must be left uncovered until inspected and approved by the City. 1.' Inspection during normal working hours only. Two (2) working days notice required. DATE: I certify that I have read and shall comply with the above PERMIT FEE: 30 o CONNECTION FEE: W DISAPPROVED By: Date: X Date: APPROVED By Date : * PERMIT MUST BE POSTED ON JOB SITE O H z 0 w z N C O 0 V Wi ZE zoo: 3 W Qz a 0 LO to V O Q �O i •y i t i l i� U w Z 46,v Nq u: Q mx LC e: 714 `► t/j 6 y r f3 tad 4 _ oii co - � T H %5 PL. cc A "RV C. MOON w r Q � a r _ ,. �, z . '=--°^,>e(--= ::-�r-•^r�.`.r-=P- �w,.-�- Win.. �_ �s;� :s-�-�•-.:-�--ram--",.._.,.•,.-_ _ eo rl to �. tin v, P!. A: b � is , . _.. :� £,I 1•�U S�L�J!t:r� �b �}!.7 ,::� .'s"c. ,.;3(�J � - .. � 4 10 (i�W Gue izto:; feel jo t�1 sqr? s S ^ �� `ol PaIiwis Iou Inq 'G;:;;��:pul.'e,00i �41 C "' li Ottl fu;p2baj fulsbui luaPtiMapui us 31 (4 1t3 !0 m5A Ruy "dEw aq? Po 41101 Ps ! <i��t� �.. . ,• ; ry �rra iou saaP sPuowP3 W A310 041 'sgup;; sl:loo ,ue 0 ql Aq esn 1: ;rdBtu P�� OM ,'Ibvm UN wily.✓ 0 p" f)n,- 'q PP-P!Aoid wip'[18SCIU1 ,infra K) �"Ta 151 Aew 10 Am cq,,iZs o c-r.-=ool oqj -ol poilwil jou .riq,o ri! ul vj fdlrl.bUl lUaPL9d,'jpUl iF21PIPIM '--a )o umad -AUV dew ay?UO q)juj,',j2 fp is IOU SGOP SPUMP3 P 40 OU 'S!'l12USL0O .".2 jo fiI;o q A'q o-.n.toj pa!!eituo svvlaLu p"-a le LD —ij iO JVVM ON !3OLL0,1 ode, 8 9 0- 1 9 9 STREET FILE CITY OF EDMONDS LAURAM.HALL 250 - 5TH AVE. N.. EDMONDS, WA 98020 • (206) 771-0220 - FAX (206) 771-0221 MAYOR COMMUNITY SERVICES DEPARTMENT Public Works • Planning • Parks and Recreation • Engineering Mailed 7/23/92 July 23, 1992 J. S. Mills 16115 - 75th P1. W. Edmonds, WA 98020 SUBJECT: ACCESS SIGNS ON 75TH PL. AND 162ND ST. Mr. Mills, A site inspection of the subject intersection shows that a "Street Ends" sign is present on 162nd off of 75th P1. As "Local Access Only" would be redundant and the City has opted to use "Street Ends" in lieu of "Dead End", no further signage is necessary. Thank you for your interest. hesitate to call. Sincerely, ORDON C. HYDE Engineering Aide GCH/sdt ACCESS/TXTST530 If you have further questions, do not I f&7�— Alb e4r is • Incorporated August 11, 1890 e Sister Cities International — Hekinan, Japan SITE ADDRESS 16115 75TH PL W. EDMONDS, WA 98020 IF c3 I eJ MEADOWDALE:: MARINA. ae 0\p7C ITE RD 168th ST O VICINITY MAP N. T.S. KNOWN LAN5LIDE5 WITHIN 100FEET f EK GEOTEGH KEFOKT i'AGE 3 "KOGEK LOWE A55OCIATE5 KEPOKT 1979" iTREET FILE RECEIVED NOV 21 2012 DEVELOPMENT SERVICES COUNTER Lead Design Professional Designation and Statement The Lead Design Professional shall be Robin W. Michel. As Lead Design Professional, I have been designated by the owner/applicant to oversee and coordinate the permit review process. I have review the geotechnical report, understand its' recommendations and have incorporated into the design measures to reduce the potential risk of injury or damage from any earth movement predicted in the report. Robin W. Michel Lead Design Professional Date 4 History: Robin W. Michel has submitted three previous applications in the ESLHA, for single family houses with garages. All three applications approved by the City of Edmonds. In addition, we extended the 741h Place W roadway, from North Meadowdale Road north approximately 500 feet and installed all utilities including storm detention. J Land Clearing & Tree Cutting Plan No trees of any size will be removed and there will be minimal if any land clearing involved in this project since the location of the existing garage is currently covered in existing asphalt pavement. Please refer to the Grading Plan for any proposed detailed landscape erosion control measures. <44`K4�2 /.4 Robin W. Michel Date Lead Design Professional RECEIVED NOV 21 2012 DEVELOPMENT SERVICES . COUNTER STREET FILE 0 l 'AbjLfitx ,+ fi +r rr y 1,1 n.A s, s l 4 � /F wl -�_ a)W C �.. co L m l` r� U) icii 0 � o a� i >��m L •� a �. W'x c o c �Q o'E v V N o �, ce I :9) � C. ID CL a� as 2 3►� E-a o ® a CL Ca 7 1 ca M r4 CON m O C O- Q Co W (n f0m =m R 0 .,"ZwQ °� u� �C �N �0 CO_ v, oN �i°U � `�_ °p U) co�a`� ai N vo m a>�U c o c(D ao UQ O 2 C O— �� t' � _ Q- W 3 Z= Q C U z .� c(u N c_Oo t `�- O L N � CO O L t O m o t O= C o v O Q CD 0 � O�.--a= �� 00 U)�i L O O O /ate O L co O y O Q lot W.=Wm>� fro>W =� naci 30 0 m v a m c� � a� a� L) - 'ch o Q a) ZJ`.�..0 N (nUi 3CO z �. O N Mmom CN d ; _ r to �. J T- . U \` LO , � O O > N m N - a �z �2 a C m .0 CL CL U N O Qovw -0 ca 0 0 S �rJouv = W 0 Q $ qQ�o V N ajJ y Q E qF o �g S w LU 3 _N c wcc N � ® LU C\j � y � W V w Z o� I W 0 U. w w CD s 1 i Pursuant to Edmonds Community Development Code Chapter 19.10 sites designated within or near the North Edmonds Earth Subsidence and Landslide Hazard Area shall be designated on this map which indicates areas of earth subsidence and landslide hazards in excess of normal allowances. In order to designate the subject project development site located at 7, 711 �A J,; Edmonds, Washington, the following maps, surveys or other noted items below were used: • Geotechnical Report Prepared by ��-S7��C%/fit/ �j�i/.IUL % �ff/Y/`J f C , • Land- Survey Prepared by Ci A C'. S Y/.4,-6 "I certify under penalty of perjury that the site location designation has been made to the best of my knowledge and belief, following an investigation of all information and documentation in my possession as well as reasonably obtainable information in the possession of others, including public agencies. Any information which would tend to designate a differing location for the site is attached as a part of my designation as well as all information upon which I reasonably relied." Site Plotted by ?0, I�Y� Cff�- Date Signed � Date — l02 -/-Z Title � ),E-S"%6 "c ►� � n SSA ENGINEERING DIVISION AP qVE AS NOTE Date: 3 TEL 3 olfVIN ;�.�1T(f 9 IS R-SPDXISiCLE FOR ALCEPTABLE TIGERN R MATERIAL 2SCH O s 010 H \_4" PETRIMETER ROOF DRAIN CONVEYANCE PIPE AS NEEDED FOUNDATION OR GRADE BEAM GRAVa POCKET NOTE ENSURE A MINIMUM OF ONE SQUARE F00T OF DRAIN ROCK AROUND 7HE 4' PVC PERF PIPE PER GEOIECHNICAL RECOMMENDA710M FOOTING DRAIN DETAI 71m, CITY INSPECTION REQUIRED ON ALL EROSION CONTROL MEASURES BEFORE WORK CAN BEGIN. CB CATCH BASIN SW 114 SEC. 05, TWN. 27, RNG. 04, W.M. i$5fyEur#4 / ,SITE ADDRESS 16115 75TH PL W. r rs 3 EDMONDS, WA 98020 �1 •: � � }t Fq ftt � Yr S7 53U lY 4Ji� �}9 �,s� �i GENERAL NOTES N ' 1, ALL MATERIALS AND WORK SHOW ON THESE PLANS SHALL CONFORM TO THE CITY OF EDMONDS 19 AS A MINIMUM REQUIREMENT, ALL DISTURBED AREAS ON AND OFF S17F SHALL BE RETURNED TO 7HE MEADOWDALE :• ; : ' 'yF STANDARD PLANS AND DETAILS THE FOLLOWING SPECIFICARONS AND CODES, RULES AND REGULATIONS: EQUIVALENT OR THEIR PREC'ONSTRUCTION CONDITION IN ACCORDANCE WITH APPROPRIATE REQUIREMENTS MARINA. -CURRENT INTERNATIONAL BUILDING CODE (IBC) AND STANDARDS I -2010 WSDOT/APWA STANDARD SPEaRCA710NS FOR ROAD, BRIDGE AND MUNICIPAL CONSMUC77ON a 5 I T E �� -WASHINGTON STATE DEPARTMENT OF ECOLOGY S70RMWATE•i MANUAL FOR THE PUGET SOUND BASIN 20. ALL DISTURBED SOt AREAS SHALL BE SEEDED OR STABILIZED BY 07HER ACCEPTABLE METHODS FOR THE ' (CURRENT ED171ON) PRM77ON OF ON -SITE EROSION AFTER THE COMPLETION OF CONSTRUCTION. SEE EROSION CONTROL �Z PLANS FOR SPECIFIC GRADIN AND EROSION CONTROL REQUIRMENTS / ' 2 STANDARD PLAN AND TYPE NUMBERS INDICATED ON THESE DRAWINGS REFER 70 CITY OF EDMONDS 21. THE CONTRACTOR SHALL KEEN' OFF -SITE STREETS CLEAN AT ALL TIMES 8Y SWEEPP1NG WASHING OF STANDARD DETAILS UNLESS N07ED OTHERMSE THESE STREETS WILL NOT ALLOWED WITHOUT PRIOR APPROVAL 3 A COPY OF THESE APPROVED PLANS MUST BE ON THE "RTE WHENEVER CONSTRUCTION IS IN 5� }, r PROGRESS 22 THIS PROJECT IS NOT A BALANCED EAR7HIM RK PROJECT. BOTH EXPORT AND IMPORT OF SOIL AND r r ROCK MATERIALS ARE REQUIRED; 4 DEWA71ONS FROM THESE PLANS MUST BE APPROVED BY THE ENGINEER OF RECORD AND THE LOCAL GOVERNING AUTHORITY, 2Z SLOPEOF FINISHED GRADE SHALL BE CONSTANT BETWEEN FINISHED CONTOURS OR SPOT ELEVA71O S �� w � 168th ST SW 5, CONTRACTOR STALL RECORD ALL APPROVED DEVIATIONS FROM THESE PLANS ON A SL;7 OF "AS -BUILT' 24 FINISHED GRADE SHALL SLOPE AWAY FROM BUILDING WALLS AT MINIMUM 5% SLOPE FOR A MINIMUM 19 �9d DRAWINGS AND SHALL SUMMARIZE ALL AS BUILT COND17706 ON ONE SET OF REPRODUCIBLE DRAWINGS �O FOR SUBMITTAL TO THE OWNER PRIOR TO PROJECT COMPLETION AND ACCEPTANCE A SET OF AS -BUILT DISTANCE OF 10 FEET. DRAWINGS SHALL 8E SUBMITTED 10 THE CITY OF EDMONDS PRIOR TO FINAL APPROVAL OF THE BUILDING 21 CONTRACTOR SHALL BE RESPONSIBLE FOR AN SHALL INSTALL AND MAINTAIN SHORING AND BRACING AS OCCUPANCY11RNAL PROJECT APPROVAL NECESSARY TO PROTE', WORKERS EXISTING BUILDINGS STREETS WALKWAYS U71U71ES AND 07HER 6. ELEVAAONS SHON ARE W FEET. SEE SURVEY FOR BENCHMARK INFORMAPOV. EXSTNG AND PROPOSED IMPROVEMENTS AND EXCAVATIONS AGAINST LOSS OF GROUND OR CAVING EMBANKMENTS CONTRACTOR SHALL ALSO BE RESPONSIBLE FOR REMOVAL OF SHORING AND BRACING, Z THE LOCATIONS OF EXISTING UnUTIES AND SITE FEATURES SHOW HEREON HAVE BEEN FURNISHED BY AS REQUIRED. RD OTHERS BY FIELD SURVEY OR OBTIANED FORM AVAILABLE RECORDS AND SHOULD THEREFORE BE 26. CONIR40TOR SHALL OBTAIN APPROVAL FROM THE CITY AND FOLLOW CITY PROCEDURES FOR ALL WATER CONSIDERED APPROXIMATE ONLY AND NOT NECESSARILY COHPLETE IT IS IHE SOLE RESPONSIBILITY OF SERVICE INTERRUPTOVS HYDRANT 5HU10fFS STREET CLOSURES OR OTHER ACCESS RES1RICi110NS THE CONTRACTOR TO INDEPENDENTLY VERIFY THE ACCURACY OF ALL U77UTY LOCATIONS SHOWN AND TO SERV10 I NT SHALL NOT RELOCATE' HU ELIMINATE ANY HYDRANT WITHOUT FIRST OBTAINING WRT 10N& d FURTHER DISCOVER AND PROTECT ANY OTHER U71URES NOT SHOWN AND TO FURTHER DISCOVER AND PROTECT ANY OTHER UTILITIES NOT SHOWN HEREON NtIICH NAY BE AFFECTED BY LINE IMPLEMENTATION OFAPPROVAL FROM THE FIRE MARSHAL THIS PLAN. CONTRACTOR SHALL VERIFY LOCATION, DEPTH. SIZE; TYPE AND COVDI DON OF EigSTING U71UTY LINES AT CONNECTION OR CROSSING POINTS BEFORE TRENCHING FOR NEW UTILITIES ENGINEER 27. COORDINATE AND ARRANGE FOR ALL U77UTY CONNECTIONS UTILITY RELOCATIONS AND/OR SERVICE ASSUMES NO RESPONSIBILITY FOR THE COMPLETENESS OR ACCURACY OF THE &7S7WG U77U77ES AND SITE INTERRUPTIONS WTU THE AFFECTED OWNERS AND APPRtA°RIATE UTILITY COMPANIES COVNECTIOIS TU��, FEATUSRES PRES IED ON THESE DRAWINGS ENGINEER SHALL BE NOTIFIED IMMEDIATELY OF CONFLICTS EXISTING U77UITES SHALL BE MADE WITH ADVANCE WRITTEN APPROVAL OF THE AUTHORITIES GOVERNING�� i � � � W INAT ARISE. SAID Unu1TES r 8 CONTRACTOR WALL LOCATE AND PROTECT ALL U7IU77ES DLRWG CONSTRUCTION AND SHALL CONTACT THE 2a EXISTING U77UTY LINES IN SERVICE WHICH ARE DAMAGED DUE TD CONSTRUCTION WORK SHALL BE w QR�vE UNDERGROUND U17UIIES LOCATION SERVICE (1-800-424-5:55) AT LEAST 48 HOURS PRIOR TO o��SR�REoI ATIi PRIOR iiG BA�FlL INSPECTED AND ACCEPTED BY CITY OF EDMONDS AND QLINPIC CONSTRUCTION. O 9, CONTRACTOR SHALL VERIFY ALL COIVOnONS AND DIMENSIONS AT THE PROJECT SITE BEFORE STARTING 29 NEW UTILITY LOCATIONS ARE GENERALLY SHOWN BY DIMENSION, N IERE NO DIMENSIONS ARE INDICATED, WtGRK AND SHALL NOTIFY OWNER'S REPRE VTA71W OF ANY DISCREPANCIES, LOCATIONS MAY BE SCALED FROM DRAWINGS FIELD ADJUS7MENTS SHALL BE APPROVED BY OWNER'S ` �.. VICINITY MAP REPRESENTATIVE AND CITY. PIPE LENGTHS WERE SHOWN ARE APPROXIMATE AND MAY CHNAGE DUE TO FIELD CONDITIONS: � 30. WHERE NEW PIPE CLEARS AN EXISTING OR NEW UTILTY BY 6" OR LESS, PLACE POLYETHYLENE PLASTIC N. T.S. It. CONTRACTOR SHALL OBTAIN A COPY OF THE GE07EMNICAL REPORT (WHERE APPLICABLE) AND SHALL FOAM AS A CUSHION BETWEEN THE U17U7IES 04 Y & HAUL ROUTE 7HOROUIX.Y FAMILIARIZE HIMSEIF NTH THE CONTENTS THEREOF: ALL SITE WORK SHALL BE PERFORMED IN M/J�C STRICT COMPLIANCE W17H THE RECOMMENDATIONS OF THIS PETPORT 31. SEE MECHANICAL DRAWINGS (NNERE APPLICABLE) FOR CONTINUATION OF SITE U71U7ES WITHIN THE 12. STRUCTURAL FILL MATERIAL AND PLACEMENT SHALL CONFO'IVH TO THE RECOMMENDAAONS OF THE BUILDING: INLET (NOTE' PROJECT GEOTEHNICAL REPORT. JE`R SOCK.) 32. SEE ELECTRICAL ORAWiNS (WHERE APPLICABLE) FOR EXTERIOR ELECTRICAL WORK. 13 MANHOLES CATCH BASINS, UlIU77ES AND PAVEEMENT SHALL BEAR ON MEDIUM DENSE TO VERY DENSE 33. SEE LANDSCAPE DRAWINGS (WHERE APPLIC4 BE) FOR STE IHRAGAiiOV SYSTEM. NA77W SOIL OR COMPAACIED STRUCTURAL FILL /F SOIL IS DISTURBED. SOFT. LOOSE WET OR If ORGANIC MAITERIAL IS PRESENT AT SUBORADE ELEVATION. REMOVE AND REPLACE N1IH COMPACTED STRUCTURAL FILL PER GE07FOHNICAL REPORT EX ASPHALT. PLACE 14. SEE SURVEY AND ARCH17ECIURAL DRAWINGS FOR.DIMENSIOIS AND LOCATIONS OF BUILDINGS LANDSCAPED CITY OF EDHONDS SITE CLAWCATION WCIRKSHEET S, BRICKS SAND BAGG ETC, AREAS AND 07HER PROPOSED OR EXISTING 517E FEATURES Tjpe Area (gears feet PVC 10 PREVENT 15. SEE ARAHIIECTURAL DRAWINGS FOR PERIMETER FOUNDATION DRAINS FOUNDATIONS DRAINS SHALL BE 1. Non-RegWated 2,31i! S"r (He deck, sheet and concrete) )RAIN RADWG DUAN777ZES INDEPENDENT OF OIHER 97F DRAIN LINES AND SHALL BE IGHTLINED 70 THE S70RM DRAIN SYSTEM CUT: 175 CY -INCLUDES OVER-E7lCAVA1E OF 6-FEET IN ORDER Exempt ulat NNIERE INDICATED ON THE PLANS 2 Replaced 16. ALL REQUIRED STORMWATER FACIU77ES MUST BE CONSTRUCTED AND IN OPERATION PRIOR TO -� -� FILL: 152 CY TO PLACE SUITABLE BEARING SOIL UNDER GARAGE J. New (Post 1977) 4 -) -j -) -4 t 1268 SF INSTALLATION OF ANY PAVEMENT UNLESS 01HERWiSE APPROVED BY THE ENGINEER. 4 Miti Total Regulated Impervious Area C 0 GRADING QUANTITIES ARE ROUGH CALCULATIONS 7HAT DO (Mitigation Required if in excess of 2000 sf 17, ALL ROOF DRAINS PERIMETER FOUNDATION DRAINS, CAICH. BASINS AND OTHER EXTERNAL DRAINS SHALL NOT TAKE INTO ACCOUNT SHRINKAGE OR SWELLAGE B Total Area_Mltlgated by Existing Stormwater Management S,stem(s) - 0 BE CONNECTED 70 7HE STORM DRAINAGE SYSTEM UNLESS NOTED 07HERWISE 6.Regulated Area Not Yet Mitigated = 1,2667 -- 18. CONTRACTOR SHALL OBTAIN AND PAY FOR ALL PERMITS REQUIRED FOR INSTALLATION OF ALL 97F Z Am proposed to be Mitigated by Low Impact Development Techniques 0 IMPROVEMENTS INDICATED ON INESE DRAWINGS S Area proposed to be Mitigated through Canventlona! SW Techniques 0 EROSION & SEDIMEN TA TI DIN CON7RQL NOTES 1. DURING CONSTRUCTION, STRAW OR OTHER MATERIAL TO COVER EXPOSED EARTH SHALL BE LOCATED AND READY TO USE IF THE NEXT PEA7HER DAY FORECAST IS RAIN, THE SITE SHALL BE COVERED AT THE END OF THE DAY. 7HE SIE l SHALL BE COVERED IF THE NEXT DAY IS A NON -WORKING DAY. I SOIL STOCKPILES ARE 70 BE COVERED WITH WSQUEEN NIHIN 24 HOUPS 3 IMMEDIATELY FOLLOWING FINISH GRADING, FINAL LANDSCAPING IS TO BE INSTALLED CR HYDROSEED OR&M gREA OF EXPOSED EARTH. Fae aoe tt sf- 6701c anrt �i MIsPEC�a�� CALL THE CJTY ENGINEER INSPEC770N LINE (425-771-022D, ELT. 1326) 24 HOURS IN ADVANCE FOR ALL ENGINEERING INSPECTIONS CONSTRUCTLON 1. SMUENCE CALL ENGINEERING INSPECTION LINE (425-771-0220, EXT 1326) TO SET UP A PRE-CONS7RUCTTON MEETING WITH OWNER, CONTRACTOR, DESIGN ENGINEER, GE07ECHNICAL ENGINEER, AND CITY ENGINEER. 2 TEMPORARY EROSION CONTROL MEASURES TO BE IN PLACE AND INSPECTED PRIOR TO ANY CONSTRUCTION OR SITE CL.EARNG 3 REWEW EROSION & SEDIMENTA77ON CONTROL NOTES TE 4. CONTRACTOR IS TO PROVDDE DUST CONTROL MEASURES, AS REQUIRED INCLUDING STREET SWEEPING. T 5. ROUGH GRADE, INSTALL UTILITIES & STORM SYSTEM PER PLANS 6. DESIGN ENGINEER SHALL INSPECT KEY PROJECT ASPECTS DURING CONSTRUC770N. Z FINAL GRADE, PLACE AND HYDROSEED PER NOTES & DETAILS 8. REMOVE T.E.S.C. FACILITIES PER CITY APPROVAL. ts30050 DEYEMOPME NT APPROVAL STANDARDS FOR EROSION AND S_.___ _A11ON CONTROL 0°=) PLAN. A. ESC MINIMUM REQUIREMENTS ALL ACTIVITIES NECESSITATING A CLEARING OR (TRADING PERMIT AND ALL U77UTY PROJECTS CONSISTING OF MORE THAN 500 LINEAL FEET OF 7RENCH EXCAVATION SHALL BE REQUIRED 70 CONTROL EROSION AND SEDIMENT DURING CONSTRUCTION AND 70 PERMANENTLY STABIUZE EXPOSED SOIL RESULTING FROM COYS7RUC770N. PROJECTS INVOLVING A CRITICAL AREA MAY ALSO BE REQUIRED 70 COMPLY WITH ANY COMBINATION OF THE ESC MINIMUM REQUIREMENT& COMPLIANCE WILL BE DEMONSTRATED 7HROlGH THE IMPLEMOVIA77001 OF AN APPROVED ESC PLAN. GUIDELINES FOR PREPARING ESC PLANS ARE PROVIDED IN THE MANUAL THE PLAN MUST ADDRESS THE FOLLOWNG REQUIREMENTS: 1. ESC MINIMUM REQUIREMENT - CONSTRUCTION ACCESS ROUTE CONSTRUCTION VEHICLE ACCESS SMALL BE; WHENEVER PRAC77CAL, UM17ED TO ONE ROUTE ACCESS POINTS SHALL BE STABILIZED WITH QUARRY SPALLS OR CRUSHED ROCK 70 MINIMIZE THE TRACKING OF SEDIMENT ON70 PUBLIC ROADS. IF SEDIMENT IS TRANSPORTED ONTO A ROAD SURFACE, IHE ROADS SHALL BE GLEANED THOROUGHLY AT THE END OF EACH DAY. SEDIMENT MALL BE REMOVED FROM ROADS BY SHOVELING OR SWEEPING AND BE 7RANSPORTED 70 A CONTROLLED SEDIMENT DISPOSAL AREA WITHIN 24 HOURS STREET WA91ING SHALL BE ALLOWED ONLY AFTER SEDIMENT IS REMOVED IN IRIS MANNER. 2. ESC MINIMUM REQUIREMENT - STABILIZATION OF EXPOSED AREAS ALL SOILS EXPOSED BY LAND DISTURBING ACTIVITIES SHALL BE STABILIZED BY SUITABLE APPUCA770M OF BMPS INCLUDING; BUT NOT LIMITED 70, SOD, HYDROSE'EOING, OR OTHER VEGETA710N, PLASTIC COVERING OR MULCHING. ALL BMPS SHALL BE SELECTED, DESIGNED, AND MAINTAINED IN ACCORDANCE N7H 7HE MANUAL 7HE EXPOSED SOILS SHALL BE STABILIZED ACCORDING 70 AN APPROVED TIMETABLE: (TYPICALLY, NO SOILS SHALL REMAIN EXPOSED FOR MORE THAN MV DAYS FROM OCIOBER 1 THROUGH APRIL 30 AND NO MORE THAN SEEM N DAYS FROM MAY 1 7HRQUGH SEPTEMBER 30). 3 ESC MINIMUM REQUIREMENT - PROTECTION OF ADJACENT PROPERTIES ADJACENT PROPERTIES STALL BE PROTECTED FROM SEDIMENT DEPOSITION BY APPROPRIATE USE OF VEGETATIVE BUFFER SIRIPSy SEDIMENT BARRIERS OR FILIERS DIKES OR MULCHING OR BY A COMBINATION OF THESE MEASURES AND 07HER APPROPRIATE BMPS: 4. ESC MINIMUM REQUIREMENT - MANN7EAIANCE ALL EROSION AND SEDIMENT CONTROL BMPS SHALL BE REGULARLY INSPECTED AND MAINTAINED BY THE OWNER 70 ENSURE CONTINUED PERFORMANCE OF THEIR INTENDED FUNCTION. ALL MAINTENANCE AND REPAIR SHALL BE CONDUCTED IN ACCORDANCE W7H 7HE MANUAL 5. ESC MINIMUM REQUIREMENT - OTHER BMPS AS REQUIRED BY 7HE CITY, OTHER APPROPRIATE BMPS 70 MITIGATE THE EFFECTS OF INCREASED RUNOFF SMALL BE APPLIED 6. EROSION AND SEDIMENT CONTROL REQUIREMENT - UNDERGROUND UnLITY CONSTRUCTION. 7HE CONSTRUCTION OF UNDERGROUND UI7UIY LINES SMALL SPECNFICALL.Y ADDRESS THE FOLLOWWG: A. EROSION CONTROL FOR EXCAVATED AND STOCKPILED MATERIALa B. IRE PLACEMENT OF EXCAVATED MATERNAL WHERE CONSISTENT (WIH SAFETY AND SPACE CONSIDERATIONS SHALL BE PLACED ON THE UPHILL SIDE OF TRENCHES; C. TRENCH DEWATERING SYSIEMS (MUST DISCHARGE IN70 SEDIMENT TRAPS SEDIMENT PONDS OR OTHER ACCEPTABLE MEANS); A 71?ACKING AND SPILLING OF MATERIALS ON S7REEIS DUE 70 HAUUNG; E DAILY CLEANUP AND STREET MAINTENANCE: Z ADDITIONAL ESC MINIMUM REQUIREMENTS FOR LARGER DEVELOPMENTS ALL NEW DEVELOP&fVVT AND REDEVnOFMENT THAT INCLUDES LAND DISTURBING ACTIVITIES OF GREATER THAN, OR EQUAL TO, ONE ACRE IN ADDITION TO MEEnNG 7HE MINIMUM REQUIREMENIS SET FORTH ABOVE SMALL COMPLY WITH ESC REQUIREMENTS LISTED BELOW. TOPOGRAPHY & BOUNDARY SURVEY PROVIDED BY C&C SURVEYS d EX MINIMUM REQUIREMENT - DELINEATE CLEARING AND EASEMENT UM17S IN THE FIELD, MARK CLEARING UMI7S AND/OR ANY EASEME7NN "ACKS SE1977WICRITICAL AREAS AND 7HE BUFFERS, TREES AND DRAINAGE COURSE'S 9 ESC MINIMUM REQUIREMENT - SEDIMENT TRAPPING. PRIOR TO LEAWNG THE SI& STORM WATER RUNOFF SMALL PASS THROUGH A SEDIMENT POND OR SEDIMENT TRAP, OR OTHER APPROPRIATE BMPS SEDIMENT PONDS AND TRAPS PERIMETER DIKES SEDIMENT BARRIERS; AND OTHER BMPS INTENDED 70 TRAP SEDIMENT ON-97E SHALL BE CONSTRUCTED AS A FIRST STEP IN GRADING THESE BMPS SHALL BE FUNCTIONAL BEFORE LAND DISTURBING ACTIVITIES TAKE PLACE. EARTHEN STRUCTURES. SUCH AS DAMS, DIKES, AND DIVERSIONS SHALL BE SEEDED AND MULCHED ACCORDING 70 AN APPROVED TIMETABLE 10. ESC MINIMUM REQUIREMENT - CUT AND FILL SLOPES. CUT AND FILL SLOPES SHALL BE DESIGNED AND CONSTRUCTED IN A MANNER THAT WILL MINIMIZE EROSION. IN ADD177ON, SLOPES SHALL BE STABILIZED IN ACCORDANCE NTH H ESC REQUIREMENT NO. 2. 11. ESC MINIMUM REOUIREMENT - CONTROLLING OFF-971E EROSION PROPERTIES AND WATER WAYS DO WVSTREAM FROM DEVELOPMENT DIES SHALL BE PROTECTED FROM EROSION DUE TO INCREASES IN THE VOLUME, VELOCITY, AND PEAK FLOW RATE OF STORM WATER RUNOFF FROM INE PROJECT SITE, 12. ESC MINIMUM REQUIREMENT - STABILIZATION OF TEMPORARY CONVEYANCE CHANNELS AND OUTLETS ALL TEMPORARY ON-97E CONVEYANCE CHANNELS SHALL BE DESIGNED, CONSTRUCTED AND STABILIZED TO PREVENT EROSION FROM THE EXPECTED VELOCITY OF FLOW FROM A 1W10-YEAR, 24-HOUR FREQUENCY STORM FOR 7HE DEVELOPED COND1710N. STABILIZATION ADEQUATE 70 PREVENT EROSON OF OUTLETS, ADJACENT SIREAM BANKS, SLOPES AND DONNS7REAM REACHES SHALL BE PROVIDED AT THE OUTLETS OF ALL CONVEYANCE SYSTEMS 13 ESC MINIMUM REQUIREMENT STORY DRAIN INLET PROTECTION, ALL STORM DRAIN INLETS MADE OPERABLE DURING CONSTRUC7I0 SHALL BE PROTECTED SO THAT STORM WATER RUNOFF SHALL NOT ENTER THE CONVEYANCE SYSTEM WITHOUT FIRST BEING FILTERED OR 07HERNISE 7RE47ED TO REMOVE SEDIMENT. 14. ESC REQUIREMENTREMOVAL OF TEMPORARY BMPS ALL TEMPORARY EROSION AND SEDIMENT CONTROL BMPS SHALL BE REMOVED WITHIN 30 DAYS AFTER FINAL S17E ST461UZ471ON 1S ACHIEVED OR AFTER 7HE TEMPORARY BMPS ARE NO LONGER NEEDED. TRAPPED SEDIMENT SHALL BE REMOVED OR STABILIZED ON SITE DISTURBED SOIL AREAS RESULTING FROM REMOVAL SHALL BE PERMANENTLY STABILIZED, 15 EROSION AND SEDIMENT CONTROL (REQUIREMENT DEWATERING CO►SMUC71ON 97M DEWATERWO SYSTEMS SHALL DISCHARGE INTO A SEDIMENT TRAP OR SEDIMENT POND. W. EROSION AND SEDIMENT CONTROL REQUIREMENT - CONTROL OF POLLUTANTS 07HER THAN SEDIMENT ON CONSI RUCTION STES, ALL POLLUTANTS 07HER THAN SEDIMENT THAT OCCUR ON SITE DURING CONSTRUCTION SHALL BE HANDLED AND DISPOSED Of IN A MANNER THAT DOES NOT CAUSE C'ONTAMINA77ON OF STORM WATER. 17. EROSION AND SEDIMENT CONTROL REQUIREMENT - FINANCIAL LIABILITY. PERFORMANCE BONDING OR OTHER APPROPRIATE FINANCIAL INSTRUMENTS, SHALL BE REQUIRED FOR ALL PROJECTS TO ENSURE COMPLIANCE WITH THE APPROVED EROSION AND SEDIMENT CONTROL PLAN [ORD. 3013 9 1, 1995] RESUB MAR 0 7 2013 EjuCITY Of EpMON� O DS STREET SITE ADDRESS hl_-4 16115 torn PLACE WEST CITY ENGINEERING DIVISION DATE �; EDMONDS, WA 98020 4" PERFORATED PVC ` :' �• STRAW BALES MAY BE USED IN DESCRIPTION DATE GRADING TESC &DRAINAGE PER/ME77:R fiDOnNG DRAIN CERTAIN CIRCUMSTANCES (SEE 1 Revisions per Jan 23 2013 City Review Letter, Add grading quantiites,add Imp area calcs. 1-28-13 L . PREPAR�'D BY.' W/ WASHED GRAVEL POCKET DETAIL E110. THIS APPLICAITON ' 8 WRAPPED IN FILTER FABRIC SHALL BE MAINTAINED AT ALL 2 Revisions per January 28, 2013 letter from Landau Associates, Add Detail 2 & check valve, 2-11-13 ^� �E WAS . I, ,. MIRAR 140 OR EQUIVALENT TIMES DURING CONSTRUCIT13N �� cj PERIOD, 3 Respond to Cif Review comments dated March s, 2013, Revise GradingQuantifies 3-6-13 } o ,� ti DONNA L. BRESK.E P E FOR 6621 FOSTER SLOUGH RD. 3 5 SNOHOMISH, WA 98290 MCDONO UGH GARA GE CONSTRUCTION TEMPORARY SEDIMENT TRAP FOR CBS ffaff CONFMC'P NOTE. 3ER� �� s 0 G `` (425) 334 - 9980 005131105800900 7HE CONTRACTOR SHALL BE RESPONSIBLE FOR WNFI7NG THE LOCATION, DIMENSION AND DEPTH CIF' ALL EXISTING U7IUTIES WHETHER s/ONAL �N PHONE: TAX ID. . L 0 4 NOT TO SCALE Edmonds STD E1.3 SHOWN ON THESE' PLANS OR NOT, BY P07HOUNG THE U77U77ES AND SURVEYING IHE HORIZONTAL AND VERTICAL LOCATIONS PRIOR TO ,� FAX 425 334- 7380 CONSTRUCTION. THIS SHALL INCLUDE CALLING U71UTY LOCATE AT 1-800-424-5555 AND THEN POTHOLING ALL OF THE EXISTING UnUTIES AT THEIR LOCATIONS OF NEW Ul1UTY CROSSINGS TO PHYSICALLY VERIFY 14 HETHER OR NOT CONFLICTS EXIST. LOCA770N OF donna breske@comcast.net SCALTS: I "= 20' ISSUE DATE: 10-25-12 SET NO. 1 OF 1 SAID UlIU77ES AS SHOWN ON THESE PLANS ARE BASED UPON THE UNVERIFIED PUBLIC INFORMATION AND ARE SUBJECT TO VARIATION. HEIGHT CALCULATION A 85.75' E3.84.15' C. &3.95' D. &3Z TOTAL I4 = 54.40' ENGINEERING DIVISION A" J�JD S NOTE _Date: ALL E 3C L :.1=C� SUFs 1Q.Izi I '� FE COMEPED. IiVITHN 2 V* 4) 0Vgp,Fi�JC0;4' T RAOT ��3 15 i'F 06 3 91 LE FOR F 0 10 4 00e -I 1-,0L B ►'12 UA= el � 0 IMPERVIOUS SURFACE CALCULATION EXISTING HOUSE W/ EAVE51282.92 50. FT EXI5ITNG DRIVEWAY 1514.49 50. FT. EXISTING FATI05 765.5150. FT. PKOPO5ED NEW GARAGE WIEAVES &16.00 5Q. FT (NOT COUNTED BECAUSE IT 15 OVER EXISTING DRIVEWAY) TOTAL IMPERVIOUS 3862.92 5Q.FT LOT SIZE:19035.14 5Q. FT LOT SLOPE:12% E-W TAX PARCEL NUMBER:©,1 "v1 b DATUM MARK: TOP OF 5I8" KEBAK AND KPC LOCATED AT THE NOKTHEA5T QUADRANT OF THE ENTRY DRIVE TO #164311 & 16315 75TH AVE W ELEV 78.1 & (OKTHO) APPROVED BY PLC►1 ING Zone 4-Sr- Z O Corner Flag Setbacks Required Actual Front w Sides N15 1 6 � _- desk - j0 M,n S`ta'� s ro �d(yG-wf� Rear L- ether e Za.0SD- il, mtimi,- t a k w �i� 20l 2 - Il3y - 0A V-�5-40— 1 rii � APR 2 6 2013 BUILDING DEPARWENT CITY OF: EDMONDS '01 I WA -so I Aw WLI SCALE:1" = 20'-0" S30IAH3S 1N3WdOl3A3® Z10Z T � AON I303 SSMH A rI CB D COPYRIGHT 2012 C&C SURVEYING, ITS SUCCESSORS AND/OR ASSIGNS. ALL RIGHTS RESERVED. NO PART OF THIS DRAWING MAY BE REPRODUCED BY PHOTOCOPYING, RECORDING OR BY ANY OTHER MEANS, OR STORED, PROCESSED OR TRANSMITTED BY ANY COMPUTER OR OTHER SYSTEMS WITHOUT THE PRIOR WRITTEN PERMISSION OF THE SURVEYOR. COPIES OF THIS PLAN WITHOUT AN ORIGINAL SIGNATURE AND SURVEYOR'S SEAL ARE NOT VALID. THIS DRAWING IS THE PROPERTY OF C&C SURVEYING, ITS SUCCESSORS AND/OR ASSIGNS. ANY UNAUTHORIZED USE OR REPRODUCTION OF THIS DRAWING WILL BE SUBJECT TO CIVIL PENALTIES. C Sup&,# hljj i veym, 4 Mounflake Terrace, i 98043. r 1(206)523-1654 I \ f 1 o, 0 f DERRY TP 00790400001000 \ TSOUKLAS / TP 00790400000900 l ' ` V TOPOGRAPHY SURVEY FOR THOMAS AND MONICA McDONOUGH 16115 -- 75TH PLACE WEST PROJECT EOAL DESCRIPTI LOTS 8, 9 AND 10, BLOCK 58, PLAT OF MEADOWDALE BEACH, ACCORDING TO THE PLAT THEREOF, RECORDED IN VOLUME 5 OF PLATS, PAGE 38, RECORDS OF SNOHOMISH COUNTY, WASHINGTON; EXCEPT THE NORTH HALF OF SAID LOT 8; AND EXCEPT THAT PORTION CONVEYED TO CITY OF EDMONDS FOR 75TH PLACE WEST BY DEED RECORDED UNDER AUDITOR'S FILE NUMBER 9010110126; TOGETHER WITH THE WESTERLY ON -HALF OF VACATED 74TH PLACE WEST, WHICH WOULD ATTACH BY OPERATION OF LAW PURSUANT TO CITY OF EDMONDS ORDINANCE NO. 2797 RECORDED UNDER AUDITOR'S FILE NUMBR 9010110127; AND TOGETHER WITH THE WESTRLY 11.0 FEET OF THE EASTERLY ONE-HALF OF VACATED 74TH PLACE WEST IN THE CITY OF EDMONDS, WASHINGTON, BETWEEN THE NORTHERLY BOUNDARY, AS EXTENDED EASTERLY, OF THE SOUTH HALF OF LOT 8, BLOCK 58, AND THE SOUTHERLYL BOUNDARY AS EXTENDED EASTERLY OF OT 10, BLOCK 58, SAID PLAT OF MEADOWDALE BEACH; TOGETHER WITH AN EASEMENT FOR INGRESS AND EGRESS AS GRANTED BY QUIT CLAIM DEED AND EASEMENT RECORDED LINER RECORDING NUMBER 90101120368, RECORDS OF SNOHOMISH COUNTY, WASHINGTON; SITUATE IN THE COUNTY OF SNOHOMISH, STATE OF WASHINGTON. (FROM LEGAL DESCRIPTION EXHIBIT, CHICAGO TITLE COMPANY, SCHEDULE A, POLICY NUMBER 005256707, DATED MAY 2, 2012. AS PROVIDED BY CLIENT) CONTAINS 30,000.0 SO. FT. (0.12 AC.) VERTICAL DATUM - NAVD88. SNOHOMISH COUNTY SURVEY DESIGNATION 2063 - CAD #, DB ID 17869. TOP OF 5/8" REBAR AND RPC LOCATED AT THE NORTHEAST QUADRANT OF THE ENTRY DRIVE TO #164311 & 16315 75TH AVE. W. ELEV = 78.18 (ORTHO) SURVEYOR'S NOTES: 1.) THE CONTROLS SHOWN REPRESENT A COMPILATION OF MEASUREMENTS MADE DURING THIS SURVEY, PREVIOUS SURVEYS PERFORMED BY THIS FIRM, PUBLIC RECORDED SURVEYS AND MUNICIPAL RECORDS. 2.) THE CONTROLLING MONUMENTATION WAS FOUND IN JULY, 2012. CONDITIONS NOTED ARE AS OF AUGUST 6, 2012. 3.) FIELD INSTRUMENTATION WAS A LEICA TCRP 1203 TOTAL STATION LAST CALIBRATED WITHIN THE YEAR BY A FACTORY AUTHORIZED TECHNICIAN. 4.) THE LINES OF THE BOUNDARY OF THIS SURVEY ARE PER THAT CERTAIN RECORD OF SURVEY FILED UNDER RECORDING NO. 199107125003, RECORDS OF SNOHOMISH. NO BOUNDARY SURVEY WAS PERFORMED BY THIS FIRM. 5.) ANY ENCROACHMENTS SHOWN -HEREON -MAY OR MAY NOT INDICATE UNWRITTEN PROPERTY RIGHTS. _ 6.) THE BOUNDARY MARKERS AND LINES DEPICTED ON THIS MAP ARE PER RECORD TITLE INFORMATION AND REPRESENT DEED LINES ONLY. THEY DO NOT PURPORT TO SHOW OWNERSHIP LINES THAT MAY OTHERWISE BE DETERMINED BY A COURT OF LAW. WHERE DISCREPANCIES EXIST THE SURVEYOR RECOMMENDS THAT THE OWNER OR POTENTIAL PURCHASER CONSULT WITH LEGAL COUNSEL TO DETERMINE HOW BEST TO INTERPRET THEIR PROPERTY RIGHTS AND ADDRESS ANY POTENTIAL BOUNDARY DISPUTES. 7.) FENCE LINES ARE SHOWN AS MEASURED TO THE CENTERLINE OF THE FENCE POSTS. 8.) ALL DIMENSIONS NOTED ARE SHOWN IN U.S. FEET. 9.) OFFSETS AND SETBACKS ARE SHOWN PERPENDICULAR TO SIDE LINES. 10.) THE DRAWING SHOWN HEREON DOES NOT NECESSARILY CONTAIN ALL OF THE INFORMATION OBTAINED OR DEVELOPED BY THE SURVEYOR IN HIS FIELD WORK, OFFICE WORK, OR RESEARCH. UTILITY TABLE: STRUCTURE RIM INVERT SSMH A 85.56 8" N/S 78.56 SSMH B 66.74 8" N/S 58.58 SSMH C 65.24 8" N/W 57.66 SSMH D 88.25 12" N/W 78.35 6" E 80.40 SSMH E 89.90 12" N/S 79.45 CO A 67.70 12" N 65.00 12" S 64.90 6" NE 65.10 4" NE 65.30 CB B 64.55 12" N 60.45 12" S 59.95 8" E 63.25 CB C 64.70 12" N 59.05 12" S 58.95 6" N 62.05 6" S 61.65 CB D 89.67 12" W 80.22 12" NE 80.77 12" N 80.27 CB E 85.32 12" S 81.42 12" E 81.52 6" N 81.72 INLET A 82.58 - WATER FILLED 80.78 (BOX BOTTOM) NOTE: THE LOCATION OF THE WATER LINE IS PER CITY OF EDMONDS ENGINEERS, NOT VERIFIED BY THIS FIRM. RECEIVE NOV 21 2012 DEVELOCOUNT SERVICES SCALE: 120' No. Date B RevIslon PROJ NO. " = DATE: 8-7-12 2312 DRAWN BY. JJH SHEET MAP FILE: 2312TOPO '� OF '�