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20070404131341.pdfDATE: April 4, 2007 City of Edmonds PLAN REVIEW COMMENTS BUILDING DIVISION (425) 771-0220 TO: HWA GeotSciences Inc. Eric Andersen eandersen@hwageo.com FROM: Jenny Readwin, Plans Ex ine RE: Plan Check # 2007-0210 Project: Shubin SFR Project Address: 16319 75th Place W. During review of the above noted application, it was found that the following information, corrections, or clarifications are needed. Please redline plans or submit two (2) sets of revised plans/documents (affected sheets only) with a written response to each of the items below to a Permit Coordinator. 1) Reduced site plan needs to show all the information from the large site plan (undeveloped right- of-way, top and bottom rockery wall elevations, etc.). Please submit new reduced site plan scaled no smaller than 1"=20' on 8 %" x 14" or smaller paper. If all information will not fit on one page, then transfer the notes to a second page. 2) On the site plan show office bay window bumpout. 3) On the site plan clearly show undeveloped City right of way extending along the entire South property line. 4) Due to topography the datum point chosen will be impossible for the building inspector to perform the height inspection. Please chose alternate datum point that will not be altered during construction that is similar in elevation to the building pad. If an alternate datum point is not possible height verification inspection will need to be performed by a Licensed Surveyor at the owners expense. 5) An additional smoke detector is required outside the office. Because this room has a closet it is considered a sleeping room so it is also required to have a complying egress window. Please note on floor plans. The home theater/media room is also required to have complying egress. 6) The fireplace in the master bedroom must be direct vent. Please note on floor plan. 7) Show size and location of crawlspace access (Minimum 18" x 24" in floor or 16" x 24" through perimeter wall). 8) Section AA on sheet 6 shows interior footings that are not consistent with the foundation plan. Please coordinate section with foundation plan. 9) Show size and location of attic access (Minimum 22" x 30"). 10) It appears that there will be a site built shower. Provide shower pan construction detail including materials, drain, slope, etc. 11) Please complete the enclose Washington State Energy and Ventilation Code Compliance worksheet B26. 12) Number 8 of the preliminary comments by JGraf dated 12-21-06 mentioned that page 5 paragraph 5 of the Geotechnical Report is incomplete and the response was that this sentence should be deleted in its entirety. Geotechnical Engineer of Record please cross off sentence on all three copies of the reports on file with the City and date and initial change or submit new reports with line omitted. 13) The Lead Design Professional Designation and Statement is missing a portion of the last sentence "the established measures to reduce the potential risk of injury or damage from any earth movement predicted in the report" See attached #2 for required wording and revise statement accordingly. 14) Geotechnical Declaration and Statement of Risk does not include all information required. See attached #12 for required wording and submit 3 copies of new stamped and signed letter. 15) Structural Engineer Declaration must be done by the Engineer of Record and include the wording in attached 413. Please respond to #4 of attached Structural Consultant Comments regarding Engineer of.Record and revise declaration statement accordingly. 16) Special inspections are required for the following. Complete the enclosed special inspection agreement signed by the owner, the general contractor and the special inspector and submit to the City for approval prior to issuance. • Excavation/Grading/Site Prep • Placement of fill and compaction • Soil bearing verification • Pin pile installation including pile cap • Field Welding • Subsurface drainage installation • Rockery/Retaining wall placement • Temporary and final erosion control • General Site Monitoring • Final letter from Geotechnical Engineer of Record 17) See attached structural and geotechnical comments from City consultants. Respond to each item in writing. Page 2 of 2 APPLICATION CHECKLIST FOR BUILDING PERMIT SUBMITTAL APPOINTMENTS for application submittals must be scheduled with City Officials one week in advance. Only complete submittals, including full review fees, will be accepted for City review. Failure to provide the correct number of copies, plans, or other data will result in the application being rejected for review. VESTING of building permit applications is achieved when the submittal contains each and every document required by this checklist and is substantially complete in all respects. An applicant's rights shall vest when a fully complete building permit application is filed. A fully complete permit application is an application executed by owners of the property, or the duly authorized agent for such owners, contains each and every document required under the terms of these ordinances, and is substantially complete in all respects. All plans, reports and calculations must be prepared and stamped by design professionals licensed by the State of Washington. It is anticipated that minor changes or revisions may be required during any application review process. Such minor revisions or changes shall not keep an application from being deemed complete if a good faith attempt has been made to submit a substantially complete application containing all required components. A fully complete building permit application shall be accompanied by all fees, including, but not limited to, building permit fees and plan check fees. (Ordinance 92769 & ECDC 19.00.015) L CRITICAL AREAS DETERMINATION AND/OR HEARING EXAMINER DECISION One Copy A copy of the Critical Areas Determination and Hearing Examiner decision of Criticial Areas Reasonable Use Exception/Variance, or project specific Planning exemption as noted on the Critical Areas Checklist must be complete at the time of permit submittal, OR, the applicant may request concurrent review of Critical Areas ordinance compliance with the building permit review. Note, building permit review times are extended when concurrent Critical Areas review is requested. 2. LEAD DESIGN PROFESSIONAL DESIGNATION AND STATEMENT Three Copies One design professional shall act as the "lead design professional" for the applicant during the entire permit review process. This licensed professional is responsible for coordinating and incorporating recommendations of other design professionals onto the plans or into the submittal packet. This person shall submit a letter or snake a notation on the face of the plans that s/he has reviewed the geotechnical report, understands its' recommendations and have incorporated into the design the estahlich -d measures to reduce the potential risk of injury or damage from any—earth movement predicted in the 3. VICINITY MAP Original Within the packet, applicants are provided with the GeoEngineers map of the Landslide area. A signatory block on the map must be filled out by the person who locates the project site on this map. (ECDC 19.10.030) L;temp:bldg/handout/Meadow/Md_checkjlgREV06/0712005 Page 3 12. GEOTECHNICAL DECLARATION AND STATEMENT OF RISK Three Copies The geotechnical engineer shall submit a signed and notarized statement to the Building Official that includes the following language: a) In her/his judgment the plans and specifications prepared by the structural engineer conform to the recommendations in the geotechnical report and, b) That the risk of damage to the proposed development, or to adjacent properties, from soil instability will be minimal, subject to the conditions set forth in the report, and that the proposed development will not increase the potential for soil movement and, c) The statement shall include, as a condition, an evaluation setting forth the statistical probability (percentage) of earth movement within a 25 year period, the susceptibility of the risk, or hazard to correction, by on-site improvements and the measures taken to mitigate the risk or hazard. Further recommendations, signed and sealed by the geotechnical engineer, shall be provided should there be additions or exceptions to the original recommendations based on the plans, site conditions or other supporting data. (ECDC 19.10.040) 13. ARCHITECT AND/OR STRUCTURAL ENGINEER DECLARATION Three Copies 7% J The architect or structural engineer shall submit a signed and stamped statement or make a notation on the design drawings that includes the following language: that s/he has reviewed the geotechnical reports, understands its recommendations, has explained or has had explained to the owner the risk of loss due to slides on the site, and has incorporated into the design the recommendations of the report and established measures to reduce the potential risk of injury or damage that might be caused by any earth movement predicted in the report. (ECDC 19.10.040) 14. APPLICANT/OWNER COVENANT TO NOTIFY AND HOLD HARMLESS Original The owner shall execute the enclosed Covenant that will be recorded and run with the land that explains the site lies within an area of potential earth subsidence, that conditions on development are imposed, that the owner waives, indemnifies and holds harmless the City of Edmonds, its officers and employees from any claims for any loss or damage to people or property, resulting from soil movement or out of the issuance of any permit(s). The City will collect the filing fee for recording the Covenant at the time of permit issuance. (ECDC 19.10.040) L;temp:bidgfhandout/Meadow/Md_checkjigREV06/0712005 Page 6 CITY OF EDMONDS SPECIAL INSPECTION AND TESTING AGREEMENT The project at P( issued under building permit number 2-M7— 62 10 requires special inspection and/or testing per IBC Chapter 17. The complete list of special inspections is attached to this document. BEFORE A PERMIT CAN BE ISSUED: The owner and contractor and special inspector shall complete this agreement and the attached structural test(s) and inspections schedule including the required acknowledgements. APPROVAL OF SPECIAL INSPECTORS: Each special inspector shall be approved by the Building Official prior to performing any duties or inspections. Each special inspector shall submit Statement of Qualifications to the Building Official for review. Special inspectors shall display identification when performing special inspections on site. Special inspection and testing shall meet the minimum requirements of IBC Chapter 17 and the following: A. Duties and Responsibilities of the Special Inspector 1. Observe Work The special inspector shall observe the site work for conformance with the approved (stamped) plans and specifications and applicable workmanship provisions of the IBC. Architect or Engineer reviewed shop drawings may be used only as an aid to inspection. Special Inspections are to be performed on a continuous basis ---meaning that the special inspector is on site at all times observing the work requiring special inspection. Periodic inspections, if any, must have prior approval by the City based on a separate written plan reviewed and approved by the Building Official and the engineer or architect of record. 2. Report Non -conforming Items The special inspector shall bring non -conforming items to the immediate attention of the contractor and note all such items in the daily field report. Any item not resolved in a timely manner shall be immediate cause of the special inspector to notify the Building Official of the plan deviation, error, change or omission. It shall also be the duty of the special inspector to promptly notify the engineer or architect. 3. Complete Daily Reports Each special inspector shall complete and sign both the special 'inspection record. and the daily report form for each day's inspection. These records shall remain at the jobsite with the contractor for review by the City Building Inspector. 4. Furnish Weekly Reports The special inspector or inspection agency shall furnish the City with weekly reports of tests and inspections. The project engineer or architect, and others as designated shall also be copied on reports. Weekly reports must include the following: • Description of daily inspections and tests made with applicable locations • List of all non -conforming items • Report on status of non -conforming items (resolved or unresolved) • Itemized changes authorized by the Architect, Engineer and City if not included in non- conformance items. 5. Furnish Final Construction Report The special inspector or inspection agency shall submit a final signed report to the City stating that all items requiring special inspection and testing were fulfilled and reported. And, to the best of L:ITEMP1BUlLD1NG1SpeciallnspectionAgreementl13C_doc 7/04 c his/her knowledge the project is in conformance with the approved plans and specifications, approved change orders and the applicable workmanship provisions of the IBC. Items not in conformance or unresolved items or any discrepancies in inspection coverage, (i.e., missed inspections, periodic inspection when continuous inspections were required, etc.) shall be specifically itemized in this report. B. Contractor Responsibilities 1. Notify the Special Inspector It is the duty of the contractor to notify the special inspector when work is ready for special inspection. Note, the items listed on the attached schedule and as noted on the approved plans and specifications are required to have special inspections. Adequate notice shall be provided by the contractor so that the special inspector has time to become familiar with the project. 2. Provide Access to Approved Plans The contractor is responsible for providing the special inspector access to approved plans at.the jobsite. 3. Retain Special Inspection Records The contractor is responsible to retain at the jobsite all special inspection records submitted by the special inspector. These records are to be provided to the City building inspector upon request. C. City of Edmonds Building Department Responsibilities 1. Approve special inspectors or inspection agencies The building department shall approve all special inspectors and special inspection requirements. 2. Monitor special inspection and approve weekly reports Work requiring special inspection and the performance of special inspectors shall be monitored by the City Building Inspector. His/Her approval must be obtained prior to placement of concrete or other similar activities in addition to that of the special inspector. 3. Issue Certificate of Occupancy The Building Official may issue a Certificate of Occupancy after all weekly special inspection reports including the final report have been submitted and accepted. D. Owner Responsibilities The project owner or the engineer or architect of record acting as the owner's agent shall fund special inspection services. E. En2incer or Architect of Record Responsibilities The engineer or architect of record shall include special inspection requirements on the plans and specifications. ACKNOWLEDGEMENTS I have read and agree to comply with the terms and conditions of this agreement. Owner Date Special Inspector Date General Contractor Date City Building Official Date 1..:1TEMP1BUIf.DINGSISpeciallnspectionAgreementIBC.doe 7/04 J ECTAL INSPECTION AND TESTING SCHEDULE - I PR0]Mt �Ti' �'C/� iESTBIGJINSFt:Cl7CHiwYarSPEC7A1.� REINFORCED CONCRETE, GUNITE, GROUT AND MORTAR: STRUCTURAL STEEIJWELDING: Concrete Gunke Grant Mortar Sample and Test (list specific members below) Aggregate Tests — Sbop Material Identification Reinforcing Tests ` Welding inspection O Sbop ❑ Field Ma Dcsigrts — Uivasbnie Inspection ❑ Sbop ©field Reinforcing Placement high-strength Bolting Batch Pian Inspection Inspection d Shop 0 Field Inspect Placine D A325 ❑ x D Cast Samples D A49D Pick-up Samples — Metal Deck Welding inspection Compression Tests — Reinforcing Steel Welding inspection Metal Stud welding Inspection PRECAST/PRESTRESSED CONCRETE: _ Concrete Insert welding Inspection Piles Post-Tens PtrTtm Cladding AgL=F=Tcsts FIREPROOFING. Reinforcing Tests ..— Placement Inspection Tendon Tests .--- Density Tests Mu [hsiens — Thickness Tests Reinforcing Placement — Inspect Batching Insert flacement Concrete Batching INSULATING CONCRETE: Corcrctc Placement _ Sample and Test Installation Insepction — Placement Inspection Cast Samples Unit Weights Pick-up Samples Compression Tcsts FILL MATERIAL: — Acceptance Tests MASONRY ` Placement Inspection — Special Inspection Stresses Used — FwM Density. preliminary Acceptance Tests (Masonry Units. Wal! Prisms) — Subsequent Tests (Mortar. Grout. Field Wa13 Prisms) STRUCTURAL WOOD. Placement Inspection of Units _ Shear Wall Nailing Inspection .—.- Inspection of Glu-lam Fib_ _,_- Inspection of Truss Joist Fab_ ADDITIONAL INSTRUCTIONS OR OTHER TESTS — Sample and Test components AND INSPECTIONS: Fortn cotnplc" by: Title: Telephone No_: Date: Eagle Eye Consulting Engineers, P.S. PO Box 523 Olalla, WA 98359 hoytjeter@centurytel.net 360 874 0562 Fax 360 874 0591 To: Theresa Umbaugh 121 5th Avenue N Edmonds, WA 98020 Re: Shubin Residence 16319 75th Place West Edmonds, WA 98020 Plan Review # 2007-0210 E�] Date: March 17, 2007 EECE # EDM 07-10 Structure Stated Area S.F. Main floor 2721 Upper floor 2659 Total 5380 Garage 925 Total 6305 eck 530 rand total 6835 The above referenced project is in the process of plan review for compliance with Edmonds ordinances and applicable codes. The following comments, deficiencies/corrections must be addressed prior to completion of plans review and subsequent issuance of permits. Provide revised plans and calculations along with a written response to each of the items listed below to facilitate a shorter back -check time. SCOPE OF REVIEW The scope of this review is for the Structural requirements of this project. All features were checked only to the extent allowed by the submittals provided. All portions of this project are assumed to meet or will meet other departmental requirements, conditions and concerns before permit approval. a ' Page 2 of 5 EECE#: EDM 07-10 Shubin Residence STRUCTURAL COMMENTS General 2. Engineer of Record (EOR), the geotechnical report states the pin piles shall be neglected for uplift loads. It appears, based off the lateral forces, there will be uplift required to be resisted by the piles. For example, the overturning force to be resisted is 8.8 kips. Submit an analysis to justify how this force will be resolved if not using the pin pile to resist it. 3. EOR, please provide an analysis for the pile caps footings to resist the design forces. All that was stated on the drawings was 1'6" X 1'6" pile cap. This was not in the submittal packages. How was this determined? Please submit an analysis to justify. 4. The analysis and the drawings must be stamped by the same engineer. The analysis is stamped by Norm P Navarro and some drawings are stamped by Greg A. Guillen. If there are multiple engineers then an analysis must be submitted from each engineer for their potions. Also, one engineer must act as the engineer of record and review the other engineer's work and stamp the drawings so show they have reviewed them and they are in compliance with the design assumptions. Please submit this on response. See IBC 106.3.4.2. Also, the plans sheet reference details to each different engineer. For example, sheet S4 stamped by Noun P. Navarro references detail 11/S9 which is stamped by Greg A Guillian. Sheet 1 Main Floor plan 5. Architect of Record (AOR), it appears the drawings are not drawn to scale. For example, the written dimension state 19' and 4'4" which adds up 23'4" but the outside dimension is written as 18'. I used the written dimension to check the members. Please clarify which is correct and modify accordingly. of e, 2. Engineer of Record (EOR), the geotechnical report states the pin piles shall be neglected for uplift loads. It appears, based off the lateral forces, there will be uplift required to be resisted by the piles. For example, the overturning force to be resisted is 8.8 kips. Submit an analysis to justify how this force will be resolved if not using the pin pile to resist it. 3. EOR, please provide an analysis for the pile caps footings to resist the design forces. All that was stated on the drawings was 1'6" X 1'6" pile cap. This was not in the submittal packages. How was this determined? Please submit an analysis to justify. 4. The analysis and the drawings must be stamped by the same engineer. The analysis is stamped by Norm P Navarro and some drawings are stamped by Greg A. Guillen. If there are multiple engineers then an analysis must be submitted from each engineer for their potions. Also, one engineer must act as the engineer of record and review the other engineer's work and stamp the drawings so show they have reviewed them and they are in compliance with the design assumptions. Please submit this on response. See IBC 106.3.4.2. Also, the plans sheet reference details to each different engineer. For example, sheet S4 stamped by Noun P. Navarro references detail 11/S9 which is stamped by Greg A Guillian. Sheet 1 Main Floor plan 5. Architect of Record (AOR), it appears the drawings are not drawn to scale. For example, the written dimension state 19' and 4'4" which adds up 23'4" but the outside dimension is written as 18'. I used the written dimension to check the members. Please clarify which is correct and modify accordingly. Page 3 of 5 EECE#: EDM 07-10 Shubin Residence .Sheet 7 DETAILS: 6. Detail Al: EOR, please specify the required connections of the stair stingers. I was unable to find how this was being supported based off the drawings submitted. 7. Detail A4: EOR, the detail states post base per plan, but I was unable to find where this was called out. Please add this information to the drawings. Sheet S1 GENERAL NOTES & STANDARD DETAILS: 8. Detail D6: EOR, the detail states minimum (2) 2x cripples or as noted per schedule. I was unable to find the schedule on the drawings. Please clarify where this information is specified. SheetS2 FOUNDATION DETAILS: 9. Detail 10: EOR, please provide an analysis for the lateral force being transferred with (3) 16d into TH. Sheet S3 FRAMING DETIALS: 10. Detail 1 and detail 7: EOR, please provide an analysis for the timber strand end nailed at each joist to transfer the shear wall lateral forces. Per a check of analysis it appears the lateral force will not be able to transfer the required design forces. NDS 11.3 Sheet S4 FOUNDATION/MAIN FLOOR: 11. EOR, please specify the required shear wall at the diagonal wall at the entry. The analysis has used these walls for shear resistance but the drawings do not specify this wall to be a shear wall. Please add this information to the drawings. Sheet S5 UPPER FLOOR: 12. EOR, please specify the required connections of the beam mark 16 (6-3/4X12) to beam 17 (5-1/8XI2) 13. EOR, please note the plywood shall also be glued to the joist. Based off the span, it appears the joist will exceed TH's span table. Per notes the span in TH table must be reduced 6" when the floor is only nailed and not glued. Per TJI table, if the floor is glued and nailed the maximum span is 23'2" and per the drawing there appears are spans are greater then 23 feet. Please modify accordingly. Please note this is for 40 PSF LL and 10 PSF DL. Page 4 of 5 EECE4: EDM 07-10 Shubin Residence 14. EOR, please specify the size of the rafter. Detail 3/S3 just states rafter but I was unable to find the required size specified on the drawings. Sheet S5 ROOF FRAMING: 15. EOR, please provide calculations for the stud supporting the girder truss. It appears double studs will not support the design loads. Sheet S7 STRUCTUAL NOTES: 16. Please specify that a special inspection is required for the pile installations. A special inspection is required for this type of foundation system. Please note this on the drawings. Sheet S8 FOUNDATION PLAN: 17. EOR, please submit an analysis for the grade beam to transfer the force without a pile placed at the corners of the wall. For example, the wall between the dining room and kitchen. Unless a pile is placed at all change of directions of the footing/grade beam then an analysis is required to shown how the required design forces are transferred at this change of direction. Sheet S9 FOUNDATION DETIALS: 18. Section 5: EOR, provide an analysis for why there is not any shear reinforcement for the grade beam. The grade beam is required to span between piles and it appears shear reinforcement is required. ACI 11.5.5.1 19. Section 10: EOR, please clearly reference the location of where "sim." occurs. 20. Sections 7: Please note the soil shall be 8" below the top of slab or note pressure treated plywood. IBC 2304.11.2.2 Sheet S10 FOUNDATION DETIALS: 21. Section 2: EOR, please provide an analysis for the grade beam shown on this sheet. .Additional corrections may be required following receipt of corrections and additional information as requested. Your plans are being reviewed concurrently with the Building Department, Fire Department, Zoning Department and Public Works Engineering. Changes, clarifications or additional corrections may be required subsequent to the Building Department plan review when comments are received from the other concerned departments. Page 5 of 5 EECE#: EDM 07-10 Shubin Residence Should you have any inquiries regarding this letter, please contact Hoyt Jeter at (360) 874- 0562 between 8:00 a.m. and 5:00 p.m. By: Hoyt Jeter, P.E. President LANDAU ASSOCIATES TECHNICAL MEMORANDUM TAL I GEOTECHNCOL, (OAe) TO: Jeannine Graf, Building Official and Rob Chave, Planning Manager City of Edmonds, Development Services Department 121 5`h Avenue North Edmonds, Washington 98020 FROM: Dennis R. Stettler, P. E. DATE: March 28, 2007 RE: GEOTECHNICAL PEER REVIEW�g SHUBIN SINGLE FAMILY RESIDENCE C pylA/a�pq� ®u� 1631975PLACE WEST &1Z07MaSAvr EDMONDS, WASHINGTON 4,4W Y INTRODUCTION This technical memorandum provides the results of a geotechnical peer review provided on documents submitted for a building permit for a proposed single family residence at 16319 75"' Place West in Edmonds, Washington. The geotechnical peer review was accomplished for the City of Edmonds (City) in accordance with Task Order No. 07-02 of an On -Call Geotechnical Engineering Services Agreement between Landau Associates and the City of Edmonds. The project is located within the City's designated Earth Subsidence and Landslide Hazard Area and as such falls under the specific requirements of Edmonds Community Development Code (ECDC) provisions related to development in landslide hazard areas as contained in ECDC 19.10 and ECDC 23.80. A list of the documents that we were provided for this peer review is attached to this technical memorandum. Our peer review focused on the geotechnical report and related geotechnical documents. Other documents were reviewed for consistency with the geotechnical recommendations. However, our peer review did not include a technical review of the structural design or the civil design aspects of the project. GEOTECHNICAL REPORT HWA Geosciences (HWA) has prepared several documents related to this project, as listed in the attachment to this technical memorandum. HWA prepared a detailed geotechnical report in 2004 for another property owner (HWA 2004). The current site development plans are similar to those proposed by the previous property owner and HWA has prepared a 2007 gcotechnical memo (HWA 2007) for the current property owner that confirms and updates the previous recommendations prepared in 2004. HWA has also prepared a Geotechnical Declaration of Risk letter that confirms their review of the structural and civil plans for the project and summarizes the remaining landslide hazard risks related to the proposed site development. 130 2nd Avenue South + Edmonds, WA 98020 • (425) 778-0907 • fax (425) 778-6409 . www.landauinc.com The geotechnical recommendations call for supporting the structure on pin pile foundations extending down through the landslide debris into the underlying Whidbey Formation. HWA completed four borings on the site and the depth of landslide debris varied from about 31 to 50 ft below the existing ground surface at the boring locations. Each of the borings disclosed the underlying very stiff to hard Whidbey Formation. HWA estimates the length of the pin piles installed in accordance with their acceptance criteria would be about 50 to 60 ft below the proposed foundation grade beam. The structural engineer (CG Engineering) has implemented these recommendations. The geotechnical documents identify the risk associated with landslide debris flows originating from the steep slope to the east. ECDC 23.80 defines a buffer adjacent to steep slope areas of 50 ft or the height of the slope, whichever is greater. HWA indicates the subject slope is about 150 ft in height. This would imply a 150 ft wide buffer from the toe of the slope. HWA has considered the likely type of slope failure (shallow skin slides or debris flow) that could originate from the steep slope area above the property, the behavior of previous, similar slope failures, and the topography. HWA concludes that the approximately 75 ft distance between the toe of the steep slope and the house would tend to dissipate the debris flow energy and lessen the potential for significant damage to the house from a debris flow, and therefore suggest a reduced buffer of 60 ft (plus a 15 ft building setback from the buffer for a total distance of 75 ft). This is reasonable, in our opinion, and should be accepted by the City. The HWA 2004 report identifies that the fills on the site will be "minimal". The grading plans show that about 500 cubic yards of fill will be placed, primarily on the existing slope to the west of the proposed residence to expand the yard area. The height of this fill is as much as about 6 ft and the result of the fill on the existing slope would create a slope that is almost 20 ft high at a 211:1V slope. The fill is proposed to be constructed using the onsite, highly moisture sensitive, fine-grained soil and will be placed on top of existing landslide debris. In our opinion, the placement of this fill with the apparent purpose of expanding the yard is not a minimal action within this critical area. In general, it is advisable to limit the extent of fills and the creation of slopes steeper than the existing slopes in this landslide prone terrain and critical area. ECDC Chapter 23 provides that "All actions and developments shall be designed and constructed in accordance with ECDC 23.40.120, Mitigation Sequencing, to avoid, minimize, and restore all adverse impacts. Applicants must first demonstrate an inability to avoid or reduce impacts before the use of actions to mitigate potential impacts will be allowed." HWA must address the placement of this fill and the influence on slope stability for a potential failure surface originating near the top of the fill slope and emerging at or below 75h Place West. In order to allow fill material in this area, compliance to ECDC 23.40.110 and 23.40.120 must be specifically addressed by HWA. With respect to revisions to civil plans, the City requires that details on plans be presented at natural scale (no exaggerated horizontal to vertical scale in cross sections). 3128107 REdmdataYprojects107441 MRIe Rm4R\PeerReview tm.doc LANDAu ASSOCIATES 2 ROCKERY DESIGN HWA prepared a 2004 report related to rockery design. HWA also prepared a 2007 Geotechnical Memo that confirms and updates the previous 2004 rockery design recommendations. In the 2004 report, the rockery stability was evaluated and specific recommendations were provided for improvements to the rockery subgrade for foundation support and use of a wider zone than is typical for backfill materials in order to improve the calculated factor of safety. The foundation and backfill recommendations are reiterated in the 2007 memo. The report and memo also reference the City of Edmonds rockery requirements for further details. The rockery design from HWA appears to adequately address the City requirements for rockery designs. In review of the civil plans, details regarding the rockery construction requirements are lacking. The City requires that all details and construction requirements be specifically included on the plans and not simply referenced to a geotechnical report. In review of the civil grading plan (Sheet C-1), it appears that the rockery will abut the south property line and be adjacent to City right-of-way to the south. The City Rockery Permit Submittal Requirements, dated June 2006, require that rockeries on private property adjacent to City right-of-way be set back from the right- of-way a minimum horizontal distance equal to the height of the rockery. It does not appear from the plans that this minimum horizontal setback distance is achieved for the rockery in its planned location. Redesign or request for a waiver from City requirements and approval by the City Engineer is required. The civil grading plan (Sheet C-1) includes a note for the area east of the proposed driveway that states "Owner Option: Remove existing hedge as required to grade slope at 2:1 max slope, or construct a 4' min high rockery along edge of asphalt." The potential of a rockery at this location is not mentioned in the HWA report or memo. If a rockery is proposed, HWA must confirm that their recommendations apply to this rockery. We assume, given the existing and proposed ground elevations at the location of the cut slope or rockery, that the rockery height at this location would be 4 ft maximum rather than 4 ft minimum height. The City requires that plans be accurate and show the actual work that is specifically proposed rather than provide options. LAND CLEARING AND TREE CUTTING HWA has provided a letter related to land clearing and tree cutting summarizing the existing site conditions and the planned clearing and tree cutting. The plans must clearly show the extent of clearing and tree cutting and any description of land clearing and tree cutting must be consistent with the plans. HWA makes the statement "A row of cedar hedge/trees runs along the back (eastern) edge of the property and extends north to the neighboring property. These cedar trees will not be cut or disturbed by the proposed development." However, according to the civil grading plan (Sheet G1), and the TESC Plan (Sheet C-2), at 3/28101 11Edmdatalprojects1074N381Fjle Rm1R\PeerReview tm.doc LANDAU ASSOCIATES 3 least a portion of this hedge/trees will be removed and a 2:1 cut slope or rockery will be put in its place (see also the comments in this technical memorandum related to Rockery Design). This discrepancy needs to be resolved. CONSTRUCTION MONITORING Geotechnical construction observation and monitoring is necessary during key portions of the earthwork and foundation construction. We note the foundation plans prepared by CG Engineering call for periodic monitoring of the pin pile foundation construction. We concur with the recommendation of HWA that full-time monitoring of the pin pile foundation construction be provided by the geotechnical consultant. The City will require a special inspection agreement form be submitted detailing all required inspections for this project. CONFORMANCE WITH ECDC 1910 AND 23.80 In our opinion, the documents submitted for review are generally consistent with the requirements of ECDC 19.10 and 23.80. Issues to be further evaluated or addressed by the design team are as follows: • Assess the slope stability of the proposed fill on the west side of the property and the mitigation and sequencing requirements of ECDC 23.40. 110 and 23.40.120. • Modify the civil plans to include all details on the rockery construction. • Evaluate the location of the rockery as compared to City requirements for setback from public right-of-way and redesign or request formal waiver by the City Engineer. • Address the planned hedge/tree removal east of the driveway and resolve the discrepancy between the civil plans and the land clearing and tree cutting text from HWA. • The plans need to show specifically what is planned east of the driveway rather than presenting an option. If a rockery is proposed at that location, HWA must confirm that their rockery recommendations would also apply to the rockery east of the driveway. 3/28107 k%EdmdatMprojects107411381Fi1e Rm1MPeerReA9w tm.dm LANDAU AssocIATES 4 USE OF THIS TECHNICAL MEMORANDUM This technical memorandum has been prepared for use by the City of Edmonds in evaluating the adequacy of permit application documents related to the proposed Shubin single family residence at 16319 75th Place West. The focus of our review was the geotechnical aspects of the project and the purpose of our review was to assess the adequacy of the application documents for compliance with ECDC 19.10 and 23.80 requirements for development within landslide hazard areas and conformance with conventionally accepted geotechnical engineering practices. The geotechnical peer review by Landau Associates does not lessen the requirements for the applicant's geotechnical consultant and other design professionals to prepare an appropriate design for the site conditions. We appreciate this opportunity to be of service to the City of Edmonds. Please contact us if you have any questions or if we may be of further service. DRS:rgm Attachment: List of Documents 3128107 11Edmd3t3Iproleds597411381Fi1e RmXMPeerReview_tm.doc LANbAu ASSOCIATES 5 LIST OF DOCUMENTS CG Engineering. 2007. Shubin Residence Pin Piling. Oversize Plan Sheets: Sheet S7, Structural Notes; Sheet S8, Foundation Plan; Sheet S9, Foundation Details; Sheet S10, Foundation Details. Edmonds, Washington. January 11. CG Engineering. 2006. Structural Calculations for Shuhin Residence, 16319 75`h Place West, Edmonds, Washington. CG Engineering, Edmonds, Washington. October 11. Harmsen & Associates Inc. 2007a. Shubin Residence, Edmonds, Washington. Oversize Plan Sheets: Cl, Grading, Drainage, & Utility Plan; C2, TESC Plan; C3, Details & Notes. January 30. Harmsen & Associates Inc. 2007b. Shubin Residence, Pre -Platted Existing Grade Map. Monroe, Washington. February 1. HWA GeoSciences Inc. 2007a. Geotechnical Declaration of Risk, Shubin Property Development 16319 75`h Place West, Edmonds, Washington.. Prepared for A. Shubin. February 8. HWA GeoSciences Inc. 2007b. Geotechnical Memo, Proposed Development at 16319 75`h Place West, Edmonds, Washington. Prepared for A. Shubin. February 8. HWA GeoSciences Inc. 2006. Land Clearing and Tree Cutting Plan, Shubin Property Development 16319 75`h Place West, Edmonds, Washington. Prepared for A. Shubin. December 21. HWA GeoSciences Inc. 2004a. Addendum to Geotechnical Report, Rockwell Property Development, 16319 75`h Place West, Edmonds, WA, HWA Job No. 2003-174-21. Prepared for Denny Rockwell. April 23. HWA GeoSciences Inc. 2004b. Geotechnical Report; Rockwell Property Development, 16319 75th Place West, Edmonds, WA, HWA Job No. 2003-174-21. Prepared for Denny Rockwell. February 25. Lovell-Sauerland & Associates, Inc. 2004. Topography Survey for Denny Doyle Rockwell. Lynnwood, Washington. February 2. NN Engineering. 2007. Structural Calculations -Residential for Shubin Residence, 16319 75`h Place West, Edmonds, Washington. Prepared for Urban Designs, Tacoma, Washington. February 5. NN Engineering. 2006. Shubin, Edmonds, Washington, Oversize Plan Sheets: Sheet S1, General Notes, Standard Details; Sheet S2, Foundation Details; Sheet S3, Framing Details; Sheet S4, Foundation Main Floor; Sheet S5, Upper Floor; Sheet S6, Roof Framing; Sheet ST Lakewood, Washington. July 5. Project Location Designation. 2006. Landslide Hazard Map. Declaration by Eric Andersen of HWA Geosciences on GeoEngineers 1984. December 21. Urban Designs. No Date. Shubin Residence Site Plan. Tukwila, Washington. Urban Designs. No Date. Shubin Residence, Edmonds, Washington. Oversize Pian Sheets: Sheet 1 of 7, Main Floor; Sheet 2 of 7, Upper Floor; Sheet 3 of 7, Front Elevation and Left Elevation; Sheet 4 of 7, Back Elevation and Right Elevation; Sheet 5 of 7, Roof Plan; Sheet 6 of 7, Building Section A -A and Building Section B -B; Sheet 7 of 7, Miscellaneous Details; Sheet Al of 1, Notes. Tukwila, Washington. Urban Designs. No Date. Shubin Residence, Edmonds, Washington. Oversize Map: Sheet Al of 1, Notes. Tukwila, Washington. 3128/07 k\Edmda1Mprojects107411381Fi1e Rm1R\PeerReview_tm.doc LANDAU ASSOCIATES 6