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75 Pl W - 15625_Ray SFR_BLD20080376_3.pdf City of Edmonds TH 121 5 AVENUE NORTH EDMONDS, WA 98020 • (425) 771-0220 FAX(425) 771-0221 Website: www.ci.edmonds.wa.us PUBLIC WORKS DEPARTMENT Engineering Division Engineering Plan Review Comments Application #: BLD20080376 Date: October 8, 2008 Project Name/Address: Ray SFR / 15625 – 75 Place W Contact Person/Address, Fax or E-mail: Kristin Hanson / HANSONDESIGN@HOTMAIL.COM Reviewer: Edward Sibrel Division:Engineering During review of the civil drawings for the proposed project it was found that the following information, corrections, or clarifications will need to be addressed. Please resubmit 3 copies of the revised civil drawings and associated documents with a written response to each item to an Engineering Technician. Please contact me at 425-771-0220 or by e-mail at sibrel@ci.edmonds.wa.us if you have specific questions regarding these plan corrections. Review 1 – July 2, 2008 Review 2 – September 10, 2008 Review 3 – October 8, 2008 UTILITIES 1. OK 2. OK 3. OK TESC 4. OK 5. OK 6. OK DRAINAGE 7. ECDC 19.10.030(F) has the added condition that drainage designs shall be accompanied with calculations. This condition does not differentiate between impervious areas of greater or less than 5,000 square feet. The city stormwater engineer has determined that the interpretation of ECDC 19.10.030(F) is stricter than that of ECDC 18.30.060 when proposed development is within the ESLHA. Therefore, the term “calculations” with regard to storm design must include calculations of how the proper sizing of the drainage system is arrived at. As such, the use of Handout E72 to size the system is not sufficient to this purpose. Please find attached the comments from Jerry Shuster, PE – the City Stormwater Program Manager. 8. OK DATE E-MAILED October 8, 2008 PAGE(s) 1 of 1 CITY OF EDMONDS PLAN REVIEW COMMENTS ENGINEERING DIVISION (425) 771-0220 City Website: www.ci.edmonds.wa.us DATE: October 3, 2008 TO: File FROM: Jerry Shuster, P.E., Stormwater Engineering Program Manager RE: Application #: Bld20080376 Project: Ray Residence Project Address: 15625 -75th Pl. W. Item reviewed: Drainage report dated September 15, 2008 Plan sheets 1-2 During review of the above noted application, it was found that the following information, corrections, or clarifications are needed. The major items regarding site drainage that require revising include: connecting the piping for roof runoff to the upstream side of the proposed detention tank, providing more detail on the design of the interceptor trench, and providing a note for minimum cover on a pipe that is proposed in the right-of-way. In the erosion and sediment control plan, several steps in the construction sequence need to be added as well as more clearly defining the limits of clearing and the location and extent of the temporary filter fence. These items and minor revisions are detailed in the enclosed checklists. Please contact me at 425-771-0220 or by e-mail at shuster@ci.edmonds.wa.us if you have specific questions regarding these plan corrections. Page 1 of 4 brief description should be included on the destination of flows downstream of the site. Describe Change city of "Everett" to "Edmonds" on page 1Discuss the design process for sizing the interceptor drainage swale along the eastern portion of the siteAthe distance to and the nature of the nearest downstream receiving water.The "Time of Concentration" exhibit says "Slope 87 ft." Please correct. Also, the methods and the constants used to calculate the Tc should be presented in the text or the text should reference the values in the attachments.See comment 2(C)The storm system on 75th Pl W. discharges to Puget Sound via a pipe system and does not discharge into a known stream. Per City of Edmonds Code 18.30.060A.1c., the peak pre-development flows for only the 10 yr and 100yr- 24 hour design storms have to matched in the post-development condition (not the 2-yr).See Comment 2(G)See Comment 2(G)See Comment 2(G) Site:Ray Residence Date:10/2/2008 XXXXXXXXX Address:15625 75th Pl, W XXXXXXXXX N/AN/AN/A CompleteIncompleteComments By: Jerry Shuster, P.E. Stormwater Management Review Checklist (For New Developments with > 5,000 sq ft of new impervious surfaceor North Edmonds Earth Subsidence and Landslide Hazard Area ) Discuss disposition of storm water runoff before & after developmentProvide map showing general location of the site & geographical features (I)Detention system assumptions (J)Description of Water Quality Requirements for Development(J)Detention system routing computer model results (I) Description of Detention Requirements for Development (L)Other (F)(K)Water Quality Storm Calculations (A)Description of existing site (include area of site)(B)Description of Proposed Development(E)(K)Other (A)Area Calculations(B)Predeveloped Condition Runoff Curve Number(E)Post Developed Condition Time of Concentration (C)Discuss offsite drainage impacts to the site & from the site(H)Description of post developed conditions of the site(C)Predeveloped Condition Time of Concentration (D)Nearest mapped surface water body where site stormwater discharges.(D)Post Developed Condition Runoff Curve Number(H)Post Developed Condition Computer Model Results (G)Description of predeveloped assumptions for site(G)Sub basin routing(G)Predeveloped Condition Computer Model Results Project Overview NarrativeCalculations 12 10/8/2008 Page 2 of 4 The roof drain system is shown connecting to the detention system control structure. For the designed detention system to work properly, it must be connected to the inlet side of the detention pipe.See comment 3(A).The note for pipe that connects the interceptor trench water to the manhole on 75th Pl. W. should call out a minimum cover depth.The drainage report should include maintenance requirements for the on-site drainage system. Site:Ray Residence Date:10/2/2008 XXXX Address:15625 75th Pl, W XXXXXXXXXXX N/AN/AN/AN/AN/AN/AN/A CompleteIncompleteComments By: Jerry Shuster, P.E. Stormwater Management Review Checklist (For New Developments with > 5,000 sq ft of new impervious surfaceor North Edmonds Earth Subsidence and Landslide Hazard Area ) Catch Basin size/type (check size based on depth, pipe size & angles)Provide inverts of all pipes, grates, inlets, tanks, vaults & spot elev. of pond bottomMaintenance planShow location, identification and dimensions of buildings, property lines, streets, alleys & easementsShow locations of structures on abutting properties within 25 feet of proposed project site.Show section details of all retaining walls & rockeries, sections through critical portions (I)Other(I)Access road to control manhole and pond bottoms, plan & details (J)Section and plan view of control structure (F)Location and detail of emergency overflow (F)Pipe slope info versus inverts @CBs and existing pipe info (A)Label and clearly identify existing & proposed systems(B)Identify slope, length, diameter & material for all pipes(E)Downspouts; provide connection (w/ adequate depth) to retention (A)Scaled drawing of R/D pond, vault or pipe, including tract boundaries(B)Predeveloped & Finished Grade contours, show max water elev.(E)Specify soils and compaction requirements for pond construction(K)Other(A)(B) (C)(D)Catch Basin, invert elevations for all pipes(H)Flow arrows as necessary(C)Dimension all berm widths (Ponds only)(D)Show 2 cross-sections through pond, 1 must show control structure(H)(C)(D)Othe r (G)Profile storm system and show utility crossings(G)Rock protection details (L) Plan View- Drainage ConveyancePlan View & Details- Retention/ Detention (R/D) & Water QualityPlan View: Other 5 34 10/8/2008 Page 3 of 4 Comments Exent of filter fence placemnt hard to discern - clarifyNot shownSee Comment 2 A)Combine ESC notes with 18.30.050 notes By: Jerry Shuster, P.E. XX Date:10/2/2008Site:Ray ResidenceAddress:15625 75th Pl, W X XXXXXXXXXXXXX N/A CompleteIncomplete YesNo X Erosion & Sedimentation Control Checklist Grading Permit?Clearing Permit?> 500 lineal feet of trench excavation?work in a Critical area? 1) Locate drainage pipes, ditches, swales, cut-off trenches2) Temporary Pipe Inverts, or minimum slope & cover3) Grades, dimensions, location, flow direction for ditches/swales4) Bypass details for off-site runoff5) Locations and outlets for Dewatering systems3) Inspection & Maintenance of ESC devices & CBs4) Seeding, mulching, matting requirements5) Stockpiling location & protection6) Street sweeping7) Construction access8) Vehicle cleaning to prevent tracking9) Dust Control10) Other 1) Stabilization of exposed areas (verbatim by code)2) Other measures as needed to limit sediment impacts Will work entail,A) Separate Plan depicting ESC devicesB) Limits of disturbed areaC) Perimeter control, protection of adjacent areasD) Existing & Proposed ContoursE) Location of construction entrance and detailF) Identify Drainage features, streams, wetlands, seeps, swales, etcG) Show cut & fill slopes, indicating top/bottom of slope/catch linesH) Conveyance SystemJ) Provide ESC notes 12 10/8/2008 If all answers to 1 are no, ESC plan not required. Otherwise continue below. Page 4 of 4 Comments Comments Not includedNot includedNot includedThe number refenceing the modular block wall detail should be 1 not 2. XX X XXXXXXXX CompleteIncomplete CompleteIncomplete X YesNo SWM manual y Count g er DOE or Kin p Sized ) 4) Flag Clearing Limits6) CB protection7) Grading Activities8) Reference stabilization of exposed area requirements9) Utility Activities10) Removal of ESC devices only after Stabilization 11) Other12) Berm Width and Slope inside & outside slopes3) Storage info., depth, length, width4) Conveyance to Trapping Facility5) Typical Section View6) Typ. details of gravel cone, standpipe, filtering devices7) Detail control/restrictor device location & details8) Mulch and/or cover of berms and slopes9) Rock check dams, spacing, sections10) Stabilization techniques11) Other 1) Preconstruction Meeting2) Call for Utility Locations3) Review ESC notes5) Installation of ESC devices L) OtherLand disturbing activities greater than 1 acre?If all answer is no, end of checklist. Otherwise continue below.Sediment Trapping K) Construction Sequence 3 10/8/2008