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614 12TH AVE N.PDFlill 111111 642 614 12TH AVE N IN ADDRESS: A,/ TAX ACCOUNT/PARCEL #: BUILDING PERMIT (NEW STRUCTURE) #: COVENANTS (RECORDED) FOR: CRITICAL AREAS #: DETERMINATION: E] Conditional Waiver E] Study Required El Waiver CRITICAL AREAS #: DETERMINATION: El Conditional Waiver Study Required E] Waiver DISCRETIONARY PERMIT #'S: DRAINAGE PLAN DATED: PARKING AGREEMENTS DATED: EASEMENT(S) RECORD FOR: PERMITS (OTHER — list permit #'s): PLANNING DATA CHECKLIST DATED: SCALED PLOT PLAN DATED: SEWER LID FEE $: LID #: SHORT PLAT FILE: LOT: BLOCK: SIDE SEWER AS BUILT DATED: SIDE SEWER PERMIT(S) #: GEOTECH REPORT DATED: STREET USEIENCROACHMENT PERMIT #: FOR: WATER METER TAP CARD DATED: OTHER: L:\TEMP\DST's\Forms\Jana's Street File Checklist 5-14-08.doc APPLICATION for The City of Edmonds SIDE SEWER PERMIT EASEMENT No . .......................................... NEW CONSTRUCTION REPAIRS 0 OV*rNER, ... 1.�= ............................... CONTRACTOR ... ....... ��.WW ............................................ PERMIT No. �424� ADDRESS ............... N- TH LEGAL DESCRIPTION: LOT No . ......... ....... **** .......... BIX)CK No . ...................................... ANAME OF ADDITION ..... f1mis lb G -7 4 3. w -28 1 14 - I22-n-i NVE=—NLJF=- N. Approved: DATE.�� .. . ... ... ... ........................... M 6 C. A. McConnachie Construction Co. Thls permit covers work to be done -i urivate propertY WILY. i_iy ccn3tructlon on. -.�!-tbllc domain Icu.: s. marquees, qtia,j will permission 9- 776.6556 or 776-0072 81`1 Alder Street Edmonds, Washington 98020 ��t j w . - APPLICATION for The City of Edmonds SIDE SEWER PERNaT NEW CONSTRUCTION 0 REPAIRS EASEMENT No . .......................................... OWNER .... C., A. McConnachie Bob Aklin --------------------------------------------------------------------------------------------------------- CONTRACTOR .................................................................................................. PERMIT No. 614 - 12th Avenue North 6 ADDRESS.......................................................................................................... LEGAL DESCRIPTION: LOT No . .............................................. BLOCK No . ............................................ NAME OF ADDITION .......... Hi_9.9.ins Addition #1 ..... .................................................................................................................... L-1 40 Approved: DATE................................................ By ...................................................................... ­ --- ------ CITY OF EDMONDS - SIDE SEWER PERMIT WATER -SEW= DEPARnM" PERMITNO. Call 7-76-1107 for side sewer inspections BEFORE covering any Portion of 00 ru -equest. NO S&t., Sun., or holiday inspections. (Inspection will be Provided within 24 hours after r the nst etion.) ADDRESS LOCAIHON OF CONSMUCTIOIV 6) 1 'cti Avel'UK.- I'lorth - --------------------------- .................. * ................... ................. . .................. . .. . ........... ................................... . PROPERTY LEGAL DESCRIPTION ...... 6� - 3 L ..ns �Aiition .. .. .. .... 19. ................... .............................................. I ...................... .................................. ...................... . .......................... . .......... . .......... . . _ ................................................. ....... . .................. . ................................... o1vvx= AxD/OR BuILDER .......... C. A. 1",IcConnachie ................................... ------------------------------ - ------------------------ q ----------- ............. * ---------------- CONTRACTOR-S NAME ADDRESS ... 'klin Dackhoe Se Pernitsdon 4 Is granted ..... 72, �i­ .. �p I for repair and/or connection of & side gyntm In amordance ......... 19._ er to t with City sew he atv sanitary Afobw ATTENTION IS CALLED TO THE FOLLOWING: NOTE No. I —The owners of the property may obtain a permit to nstruct ewer I ide y Ito side sewer in street area. Do not cover any Portion 0 co 8 ns propert e. A licensed'Side Sewer Contractor musthe employed to co NOTE No, 2—All work Performed In city right f sewer before it has been inspected. NOTE No. 3 -of-way requires an Invasion of RJght-of-Way Permit obtainable from the City Engineer's office. —Obtaln full information regarding Ordinance 11-16.030 and Regulations governing side sewers when You get permit. NOTE No. 4—Top of side sewer must have at least 30 Inches coverage at property line and 12 inches inside property line; minimum g I r sharper than % will be permitted. NOTE No. 5—Trenches in street must be water settled and surface of street restored Ode of 2,y#. No beads in work which may develop within one year of completion. to original condition. Contractors sh I be al responsible for failure due to im NOTE No. 6—It is unlawful to alter or do any other work than is Provided for in the permjt� or to do any work on the main sewer Or tU appurtenances except tbl"* sert the pipe Into the wye. t. DISAPPROVED E] Date ... ................................... By ---------------- Date ....... . . ......... Date. ---------- - - . .. . ........................ . .......... .... . y ­­ ...... .. ........ By ........ ;4 J_i - -------- "PROVED DatB..._ Remarks: ............................ ............. . .. . ....... .................. .......... _----------------- . ..................................... . ...... ........................................... ................................................................. 4 ... . ............ -------- ................ .................................. . .............. . ................ w .................. .. . ................ ...................... . ... BOTH Pernlit Copies MUST Be Signed 13Y Owner of Firm Perforining Construction PRIOR To Request For InSpection 77t ......................... ------------ ... ... I hereby certify that the side sewer inewiation' con �Owner of Contracting Firm Performing construction) , stmeted under this MbEvAlcu in accordance with all governing ordinances of the City of Fdinonds. Dated this .............. Y --------- day of ...... 140 ..... ...... V V Check BEFORE you dig for: Water 0, G, 0, 11phone 0, power 0, Sewer 0, Other 13 14E I -A& 0014?=Ja=014 El vvbvilm n ffl, L =7 City of Edmo Critical Area Notice otecision Applicant: () (It 0i Property Owner: Critical Area File I(Z I ;'� I" - � � -A Permit Number: 03 13P Site Location: (P14 i An, W Parcel Number: Project Description: ft-rAinivig WAII (e'IFI4LC'VVIf/YI+- Fj Conditional Waiver. No critical area report is required for the project described above. I . There will be no alteration of a -Critical Area or its required buffer. 2. The proposal. is an allowed activity pursuant to ECDC 23.40.220, 23.50.220, and/or 23.80.040. 3. The proposal is exempt pursuant to ECDC 23.40.230. Erosion Hazard. Project is within erosion hazard area. Applicant must prepare an erosion and sediment control plan in compliance with ECDC 18.30. Critical Area Report Required. The proposed project is within a critical area and/or a critical area buffer and a critical area report is required. A critical area report has been submitted and evaluated for liance with the following criteria pursuant to ECDC 23.40.160: 1. C2 The proposal minimizes the impact on critical areas in accordance with ECDC 23.40.120, Mitigation sequencing; 2. The proposal does not pose an unreasonable threat to the public health, safety, or welfare on or off the development proposal site; 3. The proposal is consistent with the general purposes of this title and the public interest; 4. Any alterations permitted to the critical area are mitigated in accordance with ECDC 23.40.110, Mitigation requirements. 5. The proposal protects the critical area functions and values consistent with the best available science and results in no net loss of critical functions and values; and 6. The proposal is consistent with other applicable regulations and standards. F-1 Unfavorable Critical Area Decision. The proposed project is not exempt or does not adequately mitigate its impacts on critical areas and/or does not comply with the criteria in ECDC 23.40.160 and the provisions of the City of Edmonds critical area regulations. See attached findings of noncompliance. F� Favorable Critical Area Decision. The proposed project as described above and as shown on the attached site plan meets or is exempt from the criteria in' ECDC 23.40.160, Review Criteria, and complies with the applicable provisions of the City of Edmonds critical area regulations. Any subsequent changes to the proposal shall void this decision pending re -review of the proposal. F� Conditions. Critical Area specific condition(s) have been applied to the permit number referenced above. See referenced permit number for specific condition(s). Reviewer Kignature 11. IM 11 Date Appeals: Any decision to approve, condition, or deny a development proposal or other activity based on the requirements of critical area regulations may be appealed according to, and as part of, the appeal procedure, if any, for the permit or approval involved. Revised 12/16/2010 i i! A �-" X4) AL eat IWS I $14-k it lkl Olt 411-- 'Qn� . Y' 4e ej iWi. 4 Oka It �l is 4IN St fj AN -vo - k io -1 r -AID All, .01 Met v -'ere, IN TP Vl AM k�­: im Or "'Aw 1�7 V4" A av Y, , 4 .. rA 14 — is N'l 4j, , lf NO �17 .1 "N'r �l �kt 7-0 Vj�., �l U-1 'All f-v v .4t, 31 Al. W.Or 7 TZ ai "'o �4 '4N" 7X M4 'pn, Met, A.1 T; i V. 1A 1110 t�d; -j, -X:s, �p 47 -c';t CD 14 Ay, U- T k", 4, 4�I AS, A 1A Z A co C-D CD C) CD tio V1, 41,h JO el Q POO, Nj cc, CD CD C), I Nv IFIA Al 05 CO CD ,719 71 8 9 2 O� 21 62 i-493 5 61 H8-97 8-178 560 40 8-111 2030 15 H8-97 8-178 87 61 8-187� oe" i r4r, 4 Ll E7 October 27, 2011 Suzanne Ortega 308 Spring Meadow Drive Chapel Hill, NC 27517 FYI Re: Responses to City of Edmonds Review Comments Dated October 25, 2011 Permit File BLD20110310 (Ortega Retaining Walls) at 61412 th Avenue North, Edmonds, Washington Our Reference: J-034 - 01-11 Dear Suzanne: Adams Resource Consultants (ARC) has provided the attached revised report to assist you in response to the review comments provided as outlined above from the City of Edmonds (City). We supply our responses below (indicated by "ARC') directly under a copy of the applicable City comment. Where ever possible we have included an appropriate reference page and section where the comments are addressed in our previous geotechnical. report (dated October 6, 2011). 1. Heiqht: Please provide the heiqht of the walls as measured from the top of the wall to the averacie oriqinal qrade. Thev appear to be cut into the slope, but if the heiqht exceeds three feet then they are "structures" and must meet setbacks. Please clarify. As discussed at the counter with Mr. Fleming, we W need a section view of the wall showing the elevation of the top of the wall compared to the elevation of "originalgrade. " / can sign off if the wall is less than 3'tall as measured from top of wall to original grade. The location of the wall must also be shown on the site plan. ARC: We addressed this issue in ourqeotechnical report with the first paragraph on page 3 "The toe of the slope was un-retained until recent timber crib walls (less than 3 feet higher than ori0inalwade) were constructed in the slide area. " We also provided a field measured geologic cross section titled, "Figure 7: Idealized Composite Geologic Cross Section (A -A that shows the height of the crib walls confirming our statement. ARC: We have prepared a new enlat�qement of Figure 7 showing our interpretation of the originalqrade and a callout showing the measurement less than 3 feet See the new Figure 10. 2. Geotechnical Report: The report submitted does not address any of the Ortega Property Review Responses J-034 - 01 --11 October 27, 2011 critical areas ordinance, as required. ARC: We disagree with this statement and have indicated in this letter response where the ordinance was Partly or fully addressed in our original report and also provide additional information where appropriate or necessary. Please review each item contained in ECDC 23.80.070.A (copied and pasted, below) and provide assurance in writinq that these requirements can be met. An "hazards analysis" addendum to the qeotechnical report should suffice if it addresses the topics covered in the code. As discussed at the counter with Mr. Fleminq, well need an updated qeotechnical report (typically one page) with statements on how theproject complies with the critical areas ordinance, specifically the design standards in ECDC 23.80.040.A.3 (a-g). ECDC 23.80.070 Development standards - Specific hazards. A. Erosion and Landslide Hazard Areas. Activities on sites containinq erosion or landslide hazards shall meet the requirements of ECDC 23.80.060, Development Standards - General Requirements, and the specific following requirements: 1. Buffer Requirement. A buffer shall be established from all edqes of landslide hazard areas. The size of the buffer shall be determined by the director consistent with recommendations provided in the geotechnical report to eliminate or minimize the risk of property damaqe, death, or injury resulting from landslides caused in whole or part by the development, based upon review of and concurrence with a critical areas report prepared by a qualified professional. ARC: We have assumed that the ECDC buffer requirements stated above do not apply to this project since the two (tiered) crib walls constitute the only siqnificant changes (existing or planned) on the site. We understand that since the walls have been measured to not exceed 3 feet above the oriqinal .grade that they would not be considered structures and do not require a setback. ARC: We alsounderstand that the existing crib walls were completed without permit (as drawn and stamped by Dennis Bruce, P.E dated May 24, 2011) and are currently under review by the City and are referred to by the City as "Proposed. "' a. Minimum Buffer. The minimum buffer shall be equal to the heiqht of the slope existing within the project area or 50 feet, whichever is greater; b. Buffer Reduction. The buffer may be reduced to a minimum of 10 Ortega Property Review Responses October 27, 2011 J-034 - 01 --11 feet when a qualified professional demonstrates to the satisfaction of the director that the reduction will adequately protect the proposed development, adjacent developments and uses and the subject critical area; c. Increased Buffer. The buffer may be increased where the director determines that a larqer buffer is necessary to prevent risk of damage to proposed and existing development; 2. Alterations. Alterations of an erosion or landslide hazard area and/or buffer may only occur for activities for which a hazards analysis is submitted and certifies that: a. The development will not increase surface water discharge or sedimentation to adjacent properties beyond predevelopment conditions; ARC: We have addressed these issues in several places in our report and the proposed remedial measures. In our summary on page 2 of the report the last two sentences of the first paragraph indicate our assessment of current site conditions: "It is our opinion that this mechanism for erosion and slope movement will continue unless remediation measures are completed on the slope. In order to help control continued erosion the following minimum measures should be taken..." We also state in paragraph 2 on page 5; '7n our opinion the following recommended remedial measures will: a) decrease surface water discharge or sediment delivery to adjacent properties... " ARC: We will add in the report revision that our recommended minimum measures to redirect surface water are intended to decrease surface water discharge and sedimentation to adjacent properties when compared to predevelopment conditions. See page 5, second paragraph. b. The development will not decrease slope stability on adjacent properties; and ARC: We addressed slope stability in the second paraqraph ofoage 5: "In our opinion the following recommended remedial measures will; a) decrease surface water discharge or sediment delivery to adjacent properties, b) increase (meaning improve) slope stability and c) not adversely impact the critical area. " ARC: We will add the word "improve" and the phrase "'... on adjacent properties... " to our revised report text. See page 5, second paragraph. c. Such alterations will not adversely impact other critical areas; ARC: We will add the phrase ". ..or other critical areas... " to our revised Ortega Property Review Responses J-034 - 0 1 --11 October 27, 2011 report text. See page 5, second paragraph. 3. Design Standards. Development within an erosion or landslide hazard area and/or buffer shall be designed to meet the following basic requirements unless it can be demonstrated that an alternative design that deviates from one or more of these standards provides greater long-term slope stability while meeting all other provisions of this title. The requirement for long-term slope stability shall exclude designs that require regular and periodic maintenance to maintain their level of function. The basic development design standards are: a. The proposed development shall not decrease the factor of safety for landslide occurrences below the limits of 1.5 for static conditions and 1.2 for dynamic conditions. If stability at the proposed development site is below these limits, the proposed development shall provide practicable approaches to reduce risk to human safety and improve the factor of safety for landslidinq. In no case shall the existing factor of safety be reduced for the subject property or adjacent properties; ARC: We will add text to our revised report that states; "Our proposed remediation design of the slope meets the ECDC 23.80.070 factor of safety guidelines of 1.5 (static) and 1.2 (dynamic) for long-term conditions. Thus decreasing risk to this critical area and adjacent properties while at the same time avoiding regular or periodic maintenance to maintain the intended level of function." See page 5, first paragraph. b. Structures and improvements shall be clustered to avoid geologically hazardous areas and other critical areas; ARC: No new structures are proposed in our remedial design. The drainage improvements and drain rock are necessary to improve the stability of the critical area. c. Structures and improvements shall minimize alterations to the natural contour of the slope, and foundations shall be tiered where possible to conform to existing topography; ARC: We have devised a design that applies improvements that require the minimal alterations necessary to achieve the stability and drainage goals. d. Structures and improvements shall be located to preserve the most critical portion of the site and its natural landforms and vegetation; ARC: We provided improvements with this standard as a guide. e. The proposed development shall not result in greater risk or a need for Ortega Property Review Responses October 27, 2011 J-034 - 01 --11 increased buffers on neighboring properties; ARC: We addressed these standards in items A-3a and A-1 above in this response. f The use of retaining walls that allow the maintenance of existing natural slope area is preferred over graded artificial slopes; and ARC: We addressed this standard by providing a planting plan and mulch in our remediation design. g. Development shall be designed to minimize impervious lot coverage; ARC: We have assumed that this standard does not appiv to the suggested improvements because there will be no new impervious surfaces. 4. Vegetation Retention. Unless otherwise provided or as part of an approved alteration, removal of vegetation from an erosion or landslide hazard area or related buffer shall be prohibited; ARC: We have assumed that this standard does not applV to the suggested improvements because there will be no vegetation removal. Sincerely, ADAMS RESOURCE CONSULTANTS COMPANY a. sh 110 Wavm C. A&nis I WAYNE C. ADAMS, PE, PENG, EG President/CEO ADAMS Resource Consultants wayne.@AdamsResource.com October 31, 2011 Ms. Suzanne Ortega 308 Spring Meadow Drive Chapel Hill, NC 27517 Re: Revision 2 - Geotechnical Reconnaissance Report for Assessment of Environmentally Critical Area - Steep Slope Remediation 614 — 12'h Avenue North Edmonds, Washington Our Reference: J-034-01-11 Dear Suzanne: Adams Resource Consultants (ARC) provides this revision to our geotechnical report in response to the City of Edmonds (City) comments dated October 25, 2011. This report concerns our observations, opinions and recommendations of the critical area steep slope as they pertain to the December 2010 shallow landslide area At the above referenced address in the Edmonds, see Figure 1. Our original report was completed at your request following the City's requirement for a geotechnical evaluation (or hazard assessment) of the steep slope and landslide as defined by the City codes in ECDC 23.40 and 23.80. We anticipate that this report will be submitted as part of your efforts to explore remediation options and complete an engineered design and permitted slope repair. Please be aware that as a reconnaissance level investigation, we have not completed; a) relatively deep explorations such as borings, b) groundwater measurements, c) soil sample testing or d) detailed slope stability analyses. Our scope also does not include investigation of any potential contaminants or hazardous materials. During our site visit on August 30, 2011 we observed surface and subsurface conditions both in exposed areas and in "hand -dug" excavations. Our shallow excavations helped us estimate of the thickness and density of materials. We confirmed the consistency of the soil units and drain features by digging shallow (less than about 2 feet deep) "hand excavated" test pits. We measured slope angles with an inclinometer, used a metal tape to measure slope distances -and oih4-!j6.ktUf-�s','Our observations, opinions are provided below to further explain the details of oui'conclusions and recommendations. The key to some of the terminology`we use in this report is provided in the attached Appendix A. U 7 NOV 7 19 1 FLE CIW W: mi/m,1103 Ortega - Critical Areas Steep Slope October 31, 2011 J-034-01 -11 In summary, based on our observations of the site conditions and project documents we conclude that the shallow landslide (debris flow) occurred due to saturated soil from precipitation and/or elevated levels of groundwater seepage that infiltrated backfill in the sewer line trench that is part of the City's 10 feet wide utility easement. Once the fill became saturated the slope moved toward the house as a debris flow or "groundwater blowout." It is our opinion that this mechanism for erosion and slope movement will continue unless remediation measures are completed on the slope. In order to help control continued erosion the following minimum measures should be taken under the proper permit before the next rainy season or as soon as possible: • Provide design and specifications to adequately drain the timber crib walls; • Remove the temporary plastic sheeting and place mulch and a fiber blanket on the slope for erosion control; • Replant the slope in and around the slide area. In addition the following measures should be discussed with the City to see if they are willing to implement an additional level of improvement along the sewer line; • Remove the loose fill in the sewer trench above the crib walls and replace with angular drain rock or structural fill; • Place small seepage collars around the sewer pipe at the slope brow, middle and near the existing upper crib wall; • Collect seepage and direct to positive discharge west of the home. The details for these measures are provided in our conclusions and recommendations. 1.0 GENERAL BACKGROUND In preparing this report we have reviewed: 1. Original Plat Map for the Higgins Addition, submitted by Reid, Middleton & Associates, Inc., dated May, 14, 1970; 2. Various photos of the slide area, dated December 2010 and March 2011. 3. Letter report titled; "Geotechnical Evaluation - Slope Stabilization, Ortega Residence, 614 - 12'h Avenue North, Edmonds, WA", dated March 29, 2011, by Dennis Bruce; 4. A typical drawing sketch of a proposed timber crib structure and discussions, A & J Retaining Wall Company, undated; 5. Site Plan, by Dennis Bruce, dated May, 2011; Ortega - Critical Areas Steep Slope October 31, 2011 J-034-01 -11 6. City of Edmonds memorandum titled; "Planning Division comments for file BLD20110313 (Ortega Retaining Walls)," by Gina Coccia - Associate Planner, dated May 31, 2011; 7. City of Edmonds memorandum titled; "Plan Review Comments," by JoAnne Zulauf - Engineering Division, dated June 24, 2011; 8. Various City code and permit submittal requirements including ECDC 23.80.070.A; 9. Site observations and test pits by ARC in September 2011. The property is on the west facing slopes of the local community referred to as the Emerald Hills. The house on the property faces west along the east side of 12 1h Avenue North with the parking area and a garage along the east side of the house. The parking area and garage are situated between the main living quarters and the toe of the steep slope. A terraced landscape extends from the parking area up the slope along the northern portion of the back yard. The terraces are retained by an approximately 5 feet high rockery at the toe and two cement block walls higher on the slope, see Figure 2. The garage is supported on a stem wall that is approximately 4 feet high along most of the southern portion of steep slope, Figure 2. The area where the slide occurred is located south and southeast of the garage. The toe of the slope was un-retained until recent timber crib walls (less than 3 feet higher than original grade) were constructed in the slide area. See Figures 3, 4, 7 and 10. The landslide was initiated along the south edge of the property on the steep (approximately 35 to 40 degree) slope during heavy precipitation in December 2010, Figure 5. According to first hand observations and photographs (Figure 6) the slide exposed the City sewer pipe that was placed in a shallow (less than about 3 feet deep) trench along a utility easement that was part of the original plat (1970). We understand that the un-permitted crib walls were installed in the spring of 2011 according to the drawing stamped by another consulting engineer and that the walls are currently under review by the City. The crib walls are referred to by the City as "proposed." 2.0 SITE GEOLOGY AND SITE CONDITIONS 2.1 Geology The recent geologic history of the Puget Sound region has been dominated by several glacial episodes. The most recent, the Vashon stacle of the Fraser glaciation is responsible for most of the exposed geologic and topographic conditions in the area. The Puget lobe of Ortega - Critical Areas Steep Slope J-034-01 -11 October 31, 2011 the Cordilleran ice sheet left a heterogeneous deposit of pro -glacial lacustrine soil deposits, advance outwash, lodgment till, recessional outwash, and ablation till. These deposits were placed upon either bedrock or older pre-Vashon sediments and bedrock. Once the melting ice retreated northward, it uncovered a sculpted landscape of elongate uplands oriented generally northeast -southwest between intervening valleys and depressions. The project site is located within this type of terrain. 2.2 Soil Units and Slope Measurements The geologic map by Minard (1983) indicates that the project site is underlain by soil materials originating from Vashon Advanced Outwash (sand) along the lower portion of the property and by Vashon Till (silty sand and gravel) higher on property. We observed soil material of till origin on the site during our excavation of three hand dug explorations on the steep slope. Subsurface soil conditions generally included the following: Loose, dark brown, silty sand (Topsoil) from the ground surface to a maximum depth of about 1.0 feet near the top of the steep slope; Loose to medium dense, silty sand and gravel (Fill) is placed in and above the timber crib walls; Very dense, gray, silty sand and sandy gravel (Till) from a depth of about 0.5 feet to at least 3.0 feet on the steep slope. We present a composite geologic cross section (Figure 7) showing these soil units and other features. Our field developed geologic cross section shows the location of the steep slope in relation to the home and estimated landslide surface. Our measurements of the topography indicate that the steep slopes rest at maximum angles of about 40 degrees and are near vertical where faced with rockery of block walls. The observed steep slope is about 25 feet high at the location of the slide. 2.3 Groundwater We observed some seepage (perched condition) in several locations along the base of the steep slope. Although not directly observed, based on the mapped contact between the till above and outwash below it appears the highest elevation of seepage is near the contact of these two geologic units. The contact is higher than the base of the rockery shown in Figure 8. It is our interpretation that levels of groundwater seepage are elevated during portions of the rainy season (November through March). There is also a buried drain along/near the north property line. We understand that the drain pipe has recently been repaired (October, 2011) and is now functioning properly. We also viewed the house foundation, e 'o. V, T Ortega - Critical Areas Steep Slope October 31, 2011 J-034-01 -11 existing deck supports and roadway. Based on our observations there are no indications of recent structural movement such as foundation cracking, out -of -plum or offset of structures. There are also no other indications of slope stability issues in the other areas of the steep slope. 3.0 CONCLUSIONS AND RECOMMENDATIONS Based on our observations of the site conditions and project documents we conclude that the December 2010 landslide occurred due to elevated levels of groundwater seepage that infiltrated backfill in the sewer line trench. once the fill became saturated the slope reached a point of equilibrium that drove soil strength conditions to a factor of safety below 1.0 and the fill formed a debris flow or "groundwater blowout." Our proposed remediation design of the slope meets the ECDC 23.80.070 factor of safety guidelines of 1.5 (static) and 1.2 (dynamic) for long term conditions. Thus decreasing risk to this critical area and adjacent properties while at the same time avoiding regular or periodic maintenance to maintain the intended level of function. in our opinion the following recommended remedial measures will: a) decrease surface water discharge or sediment delivery to adjacent properties, b) improve slope stability on this and adjacent properties and c) not adversely impact this or other critical areas. Our recommended minimum measures to further control and/or redirect surface water are intended to decrease surface water discharge and sedimentation onto the site and adjacent properties when compared to predevelopment conditions (ECDC 23.80.60 2a). The recently constructed timber crib walls (unpermitted) improve the stability of the steep slopes on the site and the steep slopes do not pose any geotechnical issues for the walls provided the observed wall drainage is collected and transmitted to a positive discharge location. In the current configuration it appears backfill was placed behind (upslope) of the crib walls with provisions for drainage that included drain rock and perforated pipes. Currently the drain pipes discharge to a perforated pipe running south to north along the east side of the garage. Without remediation, seepage levels may rise again to saturate the fill on the slope, and would again expose the slope to further risk of movement. The drainage system that extends from the crib walls should be revised to discharge to a dry well west of the home. The slide area, currently covered by temporary plastic sheeting, should be covered with permanent erosion protection such as a thin layer of compost amended mulch covered by a fiber blanket such as jute mat. The area in and around the slide should also be planted with vegetation that will help reduce surface erosion and slow infiltration. Ortega - Critical Areas Steep Slope J-034-01 -11 October 31, 2011 We also recommend for that slide area above the crib walls you consider: a) removing the loose fill down to the top of the sewer pipe, b) placing approximately 6-inches of bedding gravel (5/8-inch minus crushed rock) on top of the pipe and c) placing a 12 to 24-inch thick drain blanket consisting of 1 to 2-inch angular drain rock above the bedding gravel in the sewer trench. Alternatively, the area could be backfilled with granular free -draining structural fill placed in stepped lifts to a maximum dry density specified in an engineered design. We have considered it possible that, during the landslide of December 2010, seepage traveled down the sewer line from upslope to the east. Although we did not observe any indications of this condition it remains a potential risk for erosion. In order to prevent this possible source of erosion in the future an additional preventive measure might include small seepage collars, made of controlled density fill (CDF) or concrete, constructed around the pipe at the brow of the slope, midway and also near the top of the upper crib wall. We recommend remedial measures be completed before the next rainy season or as soon as possible and that you retain ARC to complete the previously mentioned engineering design for remediation of the landslide area. We can also be available for review of contractor bids and construction observations as part of our added scope if you wish provided the City required monitoring/documentation of the remediation. -7 Ortega - Critical Areas Steep Slope October 31, 2011 4.0 LIMITATIONS J-034-01 -11 Work for this project was performed, and this report prepared, in accordance with our original contracts with the property owners. This work was completed with generally accepted professional practices for the nature and conditions of the work done in the same, or in similar localities, at the time the work was performed. This report is intended for the exclusive use of owners and their contractors and/or consultants for specific application to the referenced properties. ARC makes no other warranty, express or implied. Subsurface conditions interpreted from soil materials and seepage conditions encountered formed the basis for developing the recommendations in this report. The nature and extent of condItions may change over time, often vary between observation locations and differences may not become evident until the start of site work. If significant variations in conditions and/or requirements used for our recommendations appear evident, we should be consulted to re-evaluate the conclusions and recommendations in this report. It should be noted that groundwater seepage and any fluctuations in the level of the groundwater are dependent on seasonal variations in precipitation, temperature, and other climatic factors. 0"� A(' 4", , '%� �M Y,"-' Ortega - Critical Areas Steep Slope October 31, 2011 J-034-01 -11 We appreciate this opportunity to work with you on your project. If we may provide any additional information or clarification about this report, please do not hesitate to contact me on my cell at 4.25.248.8441 or by message at 425.788.3244. Sincerely, ADAMS RESOURCE CONSULTANTS COMPANY I Waym C. Adafm I WAYNE C. ADAMS, PE, PENG, EG President/CEO ADAMS Resource Consultants wayne@AdamsResource.com cc: Gina Coccia - City of Edmonds Linda Thornquist - City of Edmonds D, "T1 0-'1- ".'i, V. J P't V T 30 Vs. S A ARTHUR J. FLEMING, PIE Associate Engineer ADAMS Resource Consultants ,afleming@AdamsResource.com Ortega - Critical Areas Steep Slope October 31, 2011 FIGURES 41, , I J-034-01 -11 Ortega - Critical Areas Steep Slope October 31, 2011 APPENDIX A KEY TO SOIL DESCRIPTIONS J-034-01 -11 .171 b ft a Well -graded gravel and Relative Density or Consistency > Ow gravel with sand, little to Using Standard Penetration Test Values cc 'IT cu C If no fines Cohesionless Soils (a) Cohesive Soils (b) > 6 2 Z . LL.�� -- LO 6� Im a Density (c) N. blows/ft (c) Relative Consistency N. blows/ft (c) Undrained Shear Density % Strength(d) (pso 0 . 0 '=> — Poorly -graded gravel C: 0 3 ep and grav I with sand, Very loose 0 to 4 0 to 15 Very soft 0 to 2 < 250 0 r_ little to no fines Loose 4 to 10 15 to 35 Soft 2 to 4 250- 500 C11 6 = a I U) Z MediumDense 10to30 35 to 65 Medium Stiff 4 to 8 500-1000 Silty gravel and silty Z 21 W Dense 30 to 50 65 to 85 Stiff 8 to 15 1000-2000 C 0 4) C > ito GM gravel with sand Very Dense over 50 > 85 Very Stiff 15 to 30 2000-4000 .0— Hard over 30 > 4000 0) 0 LL - (a) Soils consisting of gravel, sand, and silt, either separately or in combination, possessing no Clayey gravel and (D cc (D �2 characteristics of plasticity, and exhibiting drained behavior. (b) Soils possessing the characteristics t2 AU Gc clayey with sand of plasticity, and exhibiting undrained behavior. (c) Refer to text of ASTM D 1586 for definition of N; in normally relative density terms are based on N values corrected for > 0 M 0 6 gravel consolidated cohesionless soils overburden pressures. (d) Undrained shear strength = 112 unconfined compression strength. LO C M Well -graded sand and Component Definitions by Gradation wc 16 2 SWI sand with gravel, little Descriptive Term Size Range and Sieve Number 0 > 0 LD '44) .......... .......... to no fines Boulders Larger than I T Z> LWL Cobbles 3" to 12" Gravel 3" to No. 4 (4.75 mm) Poorly -graded sand U) e Z SP and sand with gravel, Coarse Gravel 3" to 3/4" '0 (D 4) T 0 little to no fines Fine Gravel 3/4" to No. 4 (4.75 mm) Lo 0 M Sand No. 4 (4.75 mm) to No. 200 (0.075 mm) Silty sand and (>0' r -0.2 Coarse Sand No. 4 (4.75 mm) to No. 10 (2.00 mm) i2 C t5 — au- sm silty sand with Medium Sand No. 10 (2.00 mm) to No. 40 (0.425 mm) M 0 Co L (0 4) gravel Fine Sand No. 40 (0.425 mm) to No. 200 (0.075 mm) -0 C Q .9 Silt and Clay Smaller than No. 200 (0.075 mm) Clayey sand and M 12 Ca -0 0 �o (3) Estimated Percentage Laboratory Tests M AUN SC clayey sand with gravel Percentage by Test Designation U) , Component Weight (Trace) <5 Moisture (6) M Density D Silt, sandy silt, gravelly silt, (Few) 5 to 10 Grain Size G > ML silt with sand or gravel (Little) 15 to 25 Hydrometer H (6) If plotted a) co LO (n C (And) or adjectives 25 to 50 Atterberg Limits (6) A on log. C3 CD cc :!= With Non -primary coarse Consolidation C Unconfined U Clay of low to medium N E5 cn 0 constituents: > 15% — C; .0 CL plasticity; silty, sandy, or Fines content between UU Triax UU Z (n ca _J = gravelly clay, lean clay 5% and 15% CU Triax CU W U) 0) — E = -_ U) Adjectives: Gravelly, Sandy, or Silty CO Triax CO Organic clay or silt of low Permeability P Samples Symbols a. OL plasticity 0 Cement grout SS SPT Sampler (2.0" OD) surface seal HD Heavy Duty Split Spoon Elastic silt, clayey silt, silt a) MHJ with micaceous or SH Shelby Tube ,4) (4) Bent nite sealo CD 8 diatomaceous fine sand or P Push Tube Sampler T to 2 silt B Bulk Filter pack with A >� 0 M C Cored blank casing Clay of high plasticity, U) G Grab section 'a (D CD CH sandy or gravelly clay, fat Screened casing E clay with sand or gravel Unless otherwise noted, drive samples Z or Hydrotip with filter pack advanced with 140 lb. hammer with 30 in. drop. End cap Organic clay or silt of O-V Groundwater Seepage Cr OH medium to high (1) Percentage by dry weight (4) Depth of ground water plasticity (2) Deleted SZ ATD = At time of drilling (3) In General Accordance with _y Static water level (date) Peat, muck and other Z 0) PT highly organic soils Standard Practice for Description (5) Combined USCS DUAL symbols 25, 0 . . . 1- * ' and Identification of Soils (ASTM D-2488) I used for fines between 5% and 15% Classifications of soils in this report are based on visual field and/or laboratory observations, which include density/consistency, moisture condition, grain size, and plasticity esfimates and should not be construed to imply field or laboratory testing unless presented herein. Visual -manual and/or laboratory classificabon methods of ASTM D-2487 and D-2488 were used as an identification guide for the Unified Soil Classification System. ADAMS P. 0. BOX 1 7 70 DUVALL WA 9 801 9 SOIL DESCRIPTION METHODS RESOURCE CELL425-246-8441 msG425-766-3244 FAX666-248-IE1629 WAYNE@ADAMSRESOURCE.ORr. A& CONSULTANTS WWW.ADAMSRESOURCE.ORr. FIGURE A-1 M Yi­ " S, t"C' 4",V �51 U. "y Xlk 0,8,7, I'A "Apt" All - 'A 41W CD Ul N) CD _40 7 9 1 z c o IOZ/Sl /EO �fZ oV eTc ' 7) 14k/ Liu, 77W'V� - CD to I 's - o'-11 ok--T e& A 0! 's F- 5 ILL -a,011-09L-3 MAUti 71, 70t( aEO-TEC44. ILEPOP--r SITE7- -PIAO-ro .11* A#j.L SITS MAP Lo%%four 01; SMALL . � (D Kbet cittlB WALLS - COfJS-rk%JC-TC-j T%c A ToP -ME SANITAR-Y N BOTY& dkiTS WALLS APP"VEL AS BOW Fl. 12" GP"Pljvae:� p-T /.4 CACO, TIM 8&-IZ , /i 7' 11,cA 9 7- 2 F7- 0 Ic 2-3. SPIKES CNO)'QC-, 7-HRD44 H LEA_ S L 64 /4,ftfi� 6109E &U e�gTfw-51.- .3 919 STREET FLE a Luj E,, -@ MAY 2 4 201? qpm Tea - C) E 9 rn 9 z 0 CL Figure 1: Project Site - Plan View. Note: All locations and climenlsjq��s��are approximate. F CD) , I c, ) MV 7 -?Ml� LE nugixg cKIV 4 4 Wx Ai A 17! 1 -P S& Landslide Location (east, uphill, from and southY behind,.hedgg) NQ C) r4 CU -0 E (U M W cc 0 9 't C0 9 7! z 0 Note: All locati6ns and dimensions shown are approximate. � �� � I ',-- - - , L 'L- 5 Figure 3: Outline of Slide Scarp (Dashed Line) and Approximate Location of Sewer Pipe (Dash -dot Line); (vi looking west from top of steep slope). NOV 07 2Hj C57V 07 EMMIXOS CD C4 -0 E W M 9 Iqr (n 9 0 z 0 CL Note: All locations and di Figure 4: Location of Timber Crib Walls, (view looking south from east side of garage). re approximate. M OV 7 A Co E a) W 9 9 M 0 z 0 Note: All locations and dimensions shown are approximate. q rE3') Figure 5: Approximate Location of Timber Crib Wall, Slide and City Sewer, (view looking east from so0k'*ViGiq4r," of garaae). D��jyp�2^!xn nZPAT---MIEN7 n-7: F I C;W � -�2Y"D-MC)3 OW-2 -I 4r INN I- f. IA It AdW ip PN' W -0 E W cu East Property Estimated Line Ground Surface Southeast Corner of Garage Approximate Location of Slide Surface Silty Sand and Timber Crib Walls Gravel (Till) retaining Fill soil Approximate Uppermost Elevation of Observed Estimated Location Seepage (north of of Sewer Pipe section A-X) I I I I FM 1� j Mc- I 0 20 40 60 MOV 07 'VII Horizontal Scale in Feet (equal to vertical) c�w 07 MY0,08 Figure 7: I�ealizedl Composite Geologic Cross Section (A — X). Note: All locations and dimensions shown are approximate. Ak 1-4 (U -0 E (V CL (U lei M 0 9 9 0 z .W 0 Note: All locations and dimensions shown are approximate. Figure 8: Close-up of seepage, (view looking east from parking area.) Mun.'Dixe DF'PAR'MJKEII7' C37V 07: F_Iz!M'NLCS -4 ,-4 CD C11 0) -0 E 0) CL (U 9 CT en 9 z 0 1 Note: All locations and dimensions shown are approximate. I— — — M r Figure 9: View looking east from 12th Avenue North. ��-PD �jj Lp� Ak NOV 7 sun.umn QTV C7 9 'Cr M 9 M 0 Z 0 East Existing Ground Surface West Estimated Original Ground Surface mber 2010 Debris Flow) Distance to Original Ground (1.5 to 2.0 feet) I imber Crib Walls Retai.ning Fill Soil and Drain Gravel Distance to Original Ground 0 10 20 30 (2.0 to 2.5 feet) Scale in Feet (horizontal equals vertical) - NOV 7 Note: All locations and dimensions shown are approximate. Figure 10: Expanded View of Idealized Composite Geologic Cross Section (A — X). C"TY OF ED-Vfl0N,0,`; K�L�NQ WORK r) iR s S SD D DATE: M "ur"[Emn CX7dEdM0UdSBUHdiM'DePSft(BMt (7; 7;; AF11 "NothAng I pvnWt &pproval pro. hW, be interPrOW ae all6wing or permitting the maintenance of my curre�* nonconfo, r un frmitted or site col=nowh is outside the Of the =t application, regardlm of such , structure or condition is shmn of, the siteslan or drqwin ing, sbuctwe or _g. Such buikh 01 �n )n tion may be the &J*d of a separate enforcement actioL" APPROVED By PLANNING .�i 1+�vf of WAH SPTIRFFT HLE �1 rYN" 7:112MAM, HIGGINS ADDITION DIVISION NO, I SECTION 24, T 27N., R.3 E., W. M. EDMONDS, WASHINGTON DEDICATION /'7 A&a- -�W'ov7f& =01caf, 06 1=7= YYA6 ae.-Ahc ha':�Jsvl! . o' ;t Z; � ' � - / -- e.rmmo"e�?�r &WAX =t; SCALE: /"-Sol 7t�'e ze-�e ,/A-, u; e AIMMISYr St7 0 - Alawmfiw lvao .-.24 ..- -�MAPLIEWOOD . . ......... DESCRIPTION No. —Lj drccallal;��V Ahe P&Str7A - ' - �;r P/.r,,4:s o,� ,mxM 4 7, -&co�er ovl 9 1Z I/ =I' SOa?�AWMS-1" , �? V, Vie Clz'/Tlff� 4oyl Z-4, AAwk-w7oal YlllcWe A6. /, �eeo-al' plo Ahe '�kre /'� 'vdfv'�� 20 ce Ahr�. o'-p '�'ff$rc ZIP, --eco"alff V/ 010 ao' 1;,S 00 /VO */0 �� 7"W � effiw�-c of &/ 5.0 J'L-c;�; '��/wm et '5*&-v--fw;?&"4- 11he. -ro"7%�'6e /,>Y-- ...' Z'vyl /' */*E� -Mo�-ewl' 0.01 Me W�-ro /��c LAW zi; 0&vo7A 5 4cmc r5-ere-1% � ol,5Amice X M? -'e 8z ;ob m� et.'"e� oy�.Z."x S, 496�7'vlc lla'50y�s A� 'jolo --Ol velp�&.71 '� Zs ." IaAs 0/�' '2./b'o7!p' "/A-- Meffil ///X- h� A01,1y, 0.01 Ae ae Z87.91 Y' As'o. ACKNOWLEDGEMENT q�� �)' SIERRA STREEI 7h,,r s x10 �o�,SA -�ry -"'9m4'6A llllo� �s Me/,- 101"�"M- tcy,.rinl 7o� e4s�e5 'y e jollwyle" TEMPORARY TREE CUTTING RESTRICTION 7Acal7"AC 0= M-5ES IS ACM1617MO fV 7Ae Zr7Z~ 25 QSE;� .43QPZ,�'� MIZV *VO Q�k"9WAV 7,7(- S7Zq5V' 0GAW7VC-C Oc "-/- 407�, z-7-XC602- "W X� AE&-7- WIZL- 0lC1t---0V,- Aa5QS WIS 1155-1ZYC7AW S44�/- aQA-lY aV771- 0XZ1,02%VY P""IX5 ACE 45- -WAW lVW Ale aWeL41A429 W17711oV ;WZ XkV;' auVmm" 9s. 4v Z'l .-Vrcwzor iz VILLAGE I Zs' W. Lu > ------ -- doz ........ - — -- ------- - .. . - 7 VZ NW7 - - - I OLYMPIC JqEJGHTS NO. I SURVEYOR'S CERTIFICATE Z, e e,~ /- W10,01 eMoK Zr,,7� a& lo�hy ylh,:r Xr "^ ,rz,wye -mwhaop%y1,o" ayl ffarcllo� e-4, rZ 7Ae, A' Se, WW, 16�d/7 onodo�� -r�r 401, TREASURERIS CERTIFICATE Z y Y"c Azra.-T a,? y"a aLvt�vv-�dd '40 ' 19we. or A&AAC h-�-07 Y'�WI61 O.W�Y' t4O -/0 al7d: idZV -Me-. year APPROVALS --*X Af.4>10,e, 4-17-Y 0,-- "Mla.410-r C171 C17-Y Jwc- --0"01V,0S ,---'FILtNG- REbORD EASE9tkT----0R'OYJ8I4* --- --- --- --- A:— w h ^a � ew, 'w' r'h Me pla r"�'Acv- goa,7 '9�-- "�s �e -ell Is y m m C:) 13 6 0 M C 0 -4- (0 C: E 7-v) CL + ci--Q W CL em - C: -C"i-r- ot, (50 Ui D E V) > "o X U) 0) cu C: 0 ca 0 X LU M a) 0 0 0-0 a) > ::3 a) -0 cu E -r E 0 0 W-0 =3 0 4-- a) -0 6 u) E cc:) C(D) 1 0 M 0 a) a) C/) > 0 C: 0-o E cu 0 C: (1) C: Co (n 0— C a) 0 cu 0 - W CL 0 0 E -o --0 C a) 0) CY). LID a) M > C C: > 0 = z- 0 0) 0 (n - 0-0 .� An cu E 2 ---" C C-1 324 LLJ a) 8 E 5 0 0 - - - -------- C 0 0 0 > 0 E co a a) W Cn Co id� 0 —C: C14 14-1,Lf? V. -4c BASIS OF BEARINGS: FOUND MONUMENTS IN THE CENTER LINE OF 12TH AVENUE IN AS SHOWN ON THE PLAT OF HIGGINS ADDITION DIVISION NO . 1 BEARING N 00'ID'53" W I LEGAL DESCRIPTION: I LOT 6, HIGGINS ADDITION JIVISION NO. 1, ACCORDING TO THE PLAT THEREOF, RECO14DED IN VOLUME 32, PAGE 3, RECORDS OF SNOHOMISH qOUNTY, WASHINGTON I I C6 14 1 L 110 " N L C. F r,,l F F 7 '1:. L"I'D INFP (-)T F- 7) 71 L 'A- API'IFOX 5Z10F AR-- 329.5 X 334.0 - - - - - - - - - - - - - - + 141, PATLO (PAVER S)- IROX' 181, tit 336.0 X s AF 24'Cedar� 48"Cedar Fir 1 'Y JTUTY z"AS'.--t-/.-NT DFR PLAT 0- -11C"G NQ AD--11-!--",l 1, VO'L� 32, P-11-1 �S RESPONSIBLE FOR =�'YNOL AND DPAINAGE p" r V� 342.7 jo I? NEW PZ AN 71A 5ZZ- 0010 02 r N A 0 1P 2P FEET I C�Cktn Q FOUND SURFACE MON. FOUND EXISTING REBAR SET PK NAIL W/ SHINER ON = DOWN (P) = PLAT ? = PROPERTY LINE (M) = MEASURED INSTRUMENT DATA: (1" DIRECT READING THEODOLITE WITH E.D.M) PRECISION OF CONTROL TRAVERSE IS AT HIGHER LEVEL THAN MINIMUM STANDARDS REQUIRED F CC k BY WAC, 332-130-090. �-�.4'E OF k--- -0T THIS SURVEY WAS PERFORMED WITHOUT THE BENEFIT OF A TITLE REPORT. ANY EASEMENTS, RESTRICTIONS OR BENEFITS ARE NOT SHOWN HEREON. THIS MAP IS A REPRESENTATION OF THE CONDITIONS AT THE TIME THE FIELD SURVEY WAS PERFORMED. APPROVED BY PLANNING W6111 j!5 44-31-f"M DyiBiVlal t3 v, a A C, ( Vi a,5 �it i In 5r'+i0A F�,,.r, S, EfjD ARZA- NOTES: 1. Elevations are approximate. 2. Existing Timber Crib walls are located 3.0 feet north of Fence. Cribs are approx. &-6 wide by 6'deep by 3.0 and 3.5' tall. 3. Details of crib walls were submitted to City of Edmonds Building Dept May 24, 2011 Designed by Dennis Bruce PIE. 357 -j4K6rAL-kt-!.b--uY6 P-F-tZm jr) CR19 HIAZZ 70TAZ�)&Z- �7 - NOTT 2 F I![) E�/E4­ :;,EE-AF- -4�,F X 0,(-',12'--, OF SE C0zT,,Ez1' I '--)T 6 A L 57 1 N), (I NOV 0 7 7P '�! BUH-DING DEPAi,, mtri. CITY OF EDMONDS Z: 0 0 U) LJ 0:� L'i F- Ld IV- 0 U) CD z �7- V) 57< Ld 334.0 340 j- X, tj IT PATIO (RAVERS-)- 18 �i rr 336.0 24 Cedar(--"� Z W 12" Fir 1-ITUT' .-EMENT P- L. J- F H 1!-, —7 Z., F PLANTING NOTES AND PLANT SEQUENCE: 1. Plants to be installed du ring the period November 2011 to March 2012 2. Prior to planting the ground cover plants, Contractor shall install 3" of compost, covered by coir netting. LEGEND Staple netting to ground with 6" staples plus #3 rebar pins. Plant ground cover through coir netting. Coir netfing shall weigh 900 grams/sq meter minimum. 3. Install temporary summer irrigation soaker hoses around plants. 4. Install 5 to 7 Concrete retaining wall blocks (Keystone or equal) to support new trees on slope. In e 5. Contractor to monitor plants during the summer of 2012 and irrigate twice a week. Contractor to replace any plants that have died in the Fall of 2012. Gp, s ALL'DI,'jTuK-6q-,0 56iL,,5 Sq^Lt-186 CoyyIft5T AMej�,jbE-t, cDft SIISTV*�ZW W %-N CT-" 0 f �- G'DTYWbS +VkMW OT R- -7 Z-C- \Z\ n 342.7 341.5 V Existing Rhod /'/Grovi. �oc 0, 0 ZZ ------ OG OG 00C (V DMC -1 357 Acul,floylo.-A c rqp %) Y\cA co V e- R 'to b-C'I'NStVj ted C-1 I(elv-- e2TO ar-C-6 !E611 aq-as OWNER/CONTRACTOR IS RESPONS1136t FOR EROSION CONTROL AND DRAINAGE Type Common Name Latin Name Size Quantity Spacing, ft Tree shore pine Pinus contorta var. 4 to 5' 1 NA contotta tall Tree Vine Maple Acercircinatum 10 gal 2 NA Shrub Oregon grape Mahonia aquifolium 1 gal 12 2 Groundcover, kinnikinnik; Arctostaphylos uva-ursi 4" pot 350 1.5 East area bearberry Groundcover, kinnikinnik; Arctostaphylos uva-ursi 4" pot 65 1.5 North area bearberry N A 0-- l' FEET NOV 0 7 2011 BUILDING 1131jPAW-MENT CITY OF EDMONDS g t2 o - in I— Z Ld �< L1 m to [r -j a, :3 :) < 2 (3 u) ul Z u 0 m L3 El X I Z CD �7- 0 CL Ld Of (.D Ld Z F- < CD L'i F- Of C) I DRAWNG NUMBER I G2 N PIPING NOTES. 4 1. Connect new.2� Drain line to existing Perf pipe at base of lower Crib Wall. X 342.7 0 10 20 2.) ! Drain to be installed along base of existing fence. Pipe shall be PVC wilth > __Lzzzz;_j gt= fittings. Paint pipe to match fence. Mount pipe with steel hangers every 1.5 FEET 4 to 5 feet. j —DR), NEZZ 0 A ��A lvviCl 49fl U rvL. I V Asa 3. Dispersion trench/dry well shall be 7'long, 1.0 feet wide, and 1.33'deep. Dry 329.5 A116J VV )Z,9RAIN , OR well is located 8.5'North of property line and 15'west of House wall (6'from X �CA_ _T Existing Rhodi Deck above). Dry well is in existing landscaping area. 57 RE WAZZ"' 334.0 34 0/1 IATL 14"' 33G.0 8 9 61 8- S (APPROX) 24"Cedaro 357 EROSION CONTROL NOTES: ----------- --------------- PA 'edar —7� __11��VE 'S 0 ir 33G.0 48"Cedar 4'2 ­Vv' c I)— C a _0 r 314 4� PA�I( X) 0 24� Ced arC ed r 1 . Excavation woric shall be performed when it is not raining. Cover work area 1 T Fir Ll ---ILI I PAS::I--.-1E\I1 l-'R with existing plastic sheeting when work is not being pertomred. CF R-AT C'F AYITONI F:I\CC CIV. 1, 2. Loose landslide materail shall be removed from crib walls and trench N backfill (slide area) above crib walls. Excavated material to be removed :-3 '�2 F \1 6' `.`,.`0,0C from the site. Approximately 6 to 8 cubic yards to be removed. 3. Backfill trench area with crushed rock (see Section). Cover rock with compost and coir netting (see Planting Plan). 4. Area to be planted with ground cover per Planting Plan. C.,Cz,+0CV1 O-AM "Y�%iar coyi6ty-vcb�-an ancl +e6c- cp� 1�__ aulyw1c) ht�W y fa ityx �Ccjjv +b IL>e xfoc A0 Exist Gnd 3" Compost over Crushed Rock C 'p,%104 repov+ C. 30- 30 Remove - Backfill (11 "to 2" Crushed) loose backfill AWRO-TE LMOSLIDE AREA -W from Landslide Bedding (5/8"Crushed) REMOVE LOME LMDSLIDE MATER�L E= 3W 8"Sewer EMSTNGTIWERCRIB 355 Section B - Above Existing Sewer �H CRUSHED R MD GEOTEYTLE 350 o i-cir(or each epla 345- 2HS P"CE 58' CRUSHED ROCK BEDDNG of 4q I OVEREXISTMO O'SEMPERVA4ERE EWOS5D.SEE CROSS_%ECnON Exist Gnd 30- UD s '311WO.&4) Drain rock j * Sa'?ipini tsdrf, 43 wrapped with \- EMSTINOWSS (CLAY) Q D PTH OF COVER Geotextile ASSUNEDTOBEZ� 335 Perf PVC SEEM 320- 3M APPROVEDAS NOTED HORQONI�DISTMCE nEQ Section A - Dry Well BY EN N ERING Section C - Project Profile RESUB T% 1. 11 NOV 0 7 2011 OWNER/CONTRACTOR IS RESPONSIBLE FOR BUILDING DEPMWIMENT CITY OF MMONDS EROSION CONTROL AND DRAINAGE 0 Ln Li Of LLJ tz V) Ld 0 0- z 0 0 z 0 z 0 0 z 0 V) 0 W LJ FND 4 X4 CONC. MON, W/BRASS '*X" DOWN —25-06 0.6' IN CASE 4 m m m lop NE FACE, SW CORNER mm 14U Vi 0- -%,1 0 cup = a 1�?= - - = m ROCKERY 0.5'S X 0-51E OF NW CORNER LOT 6 cr_ CD 0 po 0 Lo im 25,00 OCKERy HEDGE CEDAR Z SW END CEDAR HEDGE w FND 4"X4 CONC. MON. n =) FND 5/8r REBAR W/NO CAP 7. W/BRASS "x" j DN. 0. 4' slm_� ;§= 0.03'W.*X 0.18'N OF ttV ICORN Ef;f---. IN CASE. 4-25-06 L-O.T. CF 4— 2 5 — 0 % < m m m mm FND 4"X4" CONC. MON. W/BRASS "X" DOWN 0.,3* IN CASE 4-25-06 FOUND SURFACE MON. FOUND EXISTING REBAR SET PK NAIL W/ SHINER DN DOWN (P) PLAT E PROPERTY LINE (M) MEASURED / 1 040 # vl 28,96' 1--A-8*32152" I I L 14.9 8 FND f 5/8= REBAR W/NO CAP 0.06 W & 0.08'N OF NE CORNER LOT 6. 4-25-06 J7 7 T_ NE END - . - �o CEDAR HEDGE c� N89*34'28"W 125.00 1 Z CEDAR HEDGE CROSSES F_ 54.01 EAST OF NW -CORNER LOT 6 cq _. 10 5 n A" A �ffh, mmm�, m 10. :L N n L_ a� r-A W. FACE KEYSTONE WALL 0.4"E OF NE CORNER LOT 6 0.3"E 0.1 FE W. FACE S. END KE YSTONE WALL ER 10" UTILITY EASEMEN -Fl # M. m 510� p0. PLAT- OF HIGGIUS- -ADDITION M. ". m M Gl it VQL.-r32� PC,3 % mm O-Z M --W. END 6 0 A—f. EN D 6 6' WOOD. EEMft WOOD FENCE WOOD FEPJGC c; N89'134 2��l 39.08 /8" REBAR W/NO FND 5� new m CAP CF.439W X 0.01'S OF SE CORNER LOT 6 7 mm mm THIS MAP CORRECTLY REPRESENTS A SURVEY MADE BY ME OR UNDER MY DIRECTION IN CONFORMANCE WITH THE REQUIREMENTS OF THE SURVEY RECORDING ACT, AT THE REQUEST OF SUZANNE ORTEGA THIS DAY OF ill tAE.: 20 41&� L.S. NO, 30435 9 S CALE** 1 BASIS OF' BEARINGS: FOUND MONUMENTS IN THE CENTER L I NE OF 12TH AVENUE N AS SHOWN ON THE PLAT OF HIGGINS ADDITION DIVISION NO.1 BEARING.-N 00*10153" W LEGAL DESCRIPTION. - LOT 6. HIGGINS ADDITION DIVISION NO. I ACCORDING 'TO THE PLAT THEREOF, RECORDED IN VOLUME 32, PAGE 3, RECORDS OF SNOHOMISH COUNTY, WASHINGTON INSTRUMENT DATA: 1, -DIRECT READING THEODOLITE WITH E.D.M) PRECISION OF CONTROL TRAVERSE IS AT HIGHER LEVEL THAN MINIMUM STANDARDS REQUIRED BY 101AC� 332-130-090. TH I.,S SURVEY WAS PERFORMED WI THOUT THE BENEFIT OF A TITLE REPORT. ANY EASEMENTS, RESTRICTIONS OR BENEFITS ARE NOT SHOWN HEREON. THIS MAP IS A REPRESENTATION OF THEi' CONDITIONS AT THE TIME THE FIELD SURVEY WAS PERFORMED. = mm wpm new 0 m m 0 e9 ." / 3 .,. C& Ow Nm_ Em SUZANNIE OR-TEPA - Ti