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bld20130460-CHC-Civil-E1.pdf CITY OF EDMONDS PLAN REVIEW COMMENTS ENGINEERING DIVISION (425) 771-0220 City Website: www.edmondswa.gov DATE:June 11, 2013 TO:Chris Kovac kpkovac@cekonw.com FROM:Jeanie McConnell, Engineering Program Manager RE:Application#:bld20130460 Project:Community Health Center Project Address: 23320 Highway 99 During review of the above notedapplication, it was found that the following information, corrections, or clarifications are needed. Please redline plans or submit three (3) sets of revised plans/documents with a written response to each of the items below to a permit coordinator. City of Edmonds handouts, standard details and development code can be referenced on the City website. GENERAL 1.Please provide an itemized engineers cost estimate, including units and unit prices, for both on- site and off-site (right-of-way) improvements,including traffic control.The City recommends use of the King County Site Improvement Bond Quantity Worksheet. A bond is required to be placed for all right-of-way improvements. The amount of the bond o will be based on 120% of the City approved estimatefor all right-of-way improvements. The City will inform you of the appropriate bond amount after review of the cost estimate. Bond forms can be obtained from Marie Harrison, Permit Coordinator –425-771-0220 or marie.harrison@edmondswa.gov Inspection fees for this project will be calculated at 2.2% of the 120% City approved o estimate for all improvements. 2.A separate permit shall be obtained from WSDOT for work within the state highway. 3.The proposed water and sewer systems fall under the jurisdiction of the Olympic View Water & Sewer District. Separate review and approval is required by the District. Upon approval of the water and sewer plans, please submit 4 copies to the City for inclusion in the final permit plan set. 4.AROW construction permit applicationwith contractors information and signature shall be submitted to the City prior to permit issuance. 5.A Special Inspection & Testing agreement will be required prior to permit issuance.Please continue to work with the Engineering Division to satisfy this requirement. bld20130460-CHC-Civil-E1.docx Page 1of 7 6.A raingarden covenant shall be recorded against the property prior final construction approval. Please continue to work with the Engineering Division to satisfy this requirement. STORMWATER REPORT The following comments from JerryShuster, Stormwater Engineer, were provided to you via email on June 4th. Please contact Jerry directly at 425-771-0220 or by email at jerry.shuster@edmondswa.govwith any specific questions you may haveregarding these comments. 1.Stormwater Technical Information Report , May 2, 2013 General: a)Add : The building footing drains will be connected to the City Stormwater system downstream of the detention vaults b)Add:A future building is planned in the area west of the proposed clinic building.An XX impervious area of ,000 square feet was assumed for the roof outline of that future building and included in the sizing of the stormwater vaults. c)Clarify the assumption of 90% lawn and 10% impervious for the asphalt and concrete areas in the modeling. d)The most recent guidance on Low Impact Development design sanctioned by the Department of Ecology states that the maximum slopes for porous asphalt is 5% and for pervious concrete is 12% - (http://www.psp.wa.gov/downloads/LID/20121221_LIDmanual_FINAL_secure.pdfsee Section 6.3). Please adjust design as needed.Also, internal check dams are required when the slope is greater than 2%.Check dam spacing isa function of the reservoir course depth (ponding depth and the slope : Spacing(ft) = ponding depth (ft) divided by slope (ft/ft)).It may be more beneficial to the project to only have porous asphalt on slopes 2% or less and make the vaults larger. This is the applicant’s call. e)Assessment of the soil infiltration rate at the location of the proposed rain gardens was not performed per one of the methods in Appendix C of the Edmonds Stormwater Code Supplement (ESCS).The Geotechrecommends confirming the infiltration rate at time of construction, but prior to construction would be better. Specific: f)Page 5-1, Section 3.1–Figure 7, referenced in the last paragraph, is not included in the report. g)Page 5-3,Section 4-The organization of this section should mirror the Minimum Requirements in Chapter 4 of the Edmonds Stormwater Code Supplement (ESCS).It should begin by classifying the project as Large Site Project using Figure 2-1 of the ESCS and then describing how the project meets all the applicable Large Site Minimum Requirements (MR). Also, under Large Site MR #5, describe the proposed use of permeable pavement and a rain garden.Describe how this will reduce the flow control requirement forMR #7 (Flow Control). In addition,MR #5 should state that the soils in the landscape areas will be amended per Ecology BMP T5.13 and will be modeled as pasture and the permeable concrete and porousasphalt will be modeled as lawn. Page 2of 7 h)Page 5-3,Section 4.1.B–Appendix IV-A of the 2005 Ecology Stormwater Management Manual for Western Washington (SWMMWW) describes pollutant generating sources for various commercial uses. Page A-18 talks about “Professional Services” business, such as this proposed clinic, and the potential pollutant sources. Include the SWMM potential pollutant sources in the report and how the owners will apply BMPs to these potential pollutant sources. Include this discussion in MR#3, Source Control. i)Page 5-3,Section 4.1.C–Use the process described inChapter 2. Volume Vof the SWMMWW, to assess the runoff treatment needs for the site. Specifically are enhanced treatment and oil control needed? Basic are phosphorus treatment is needed and provided.Also, per the ESCS Chapter 4.6.2.1, “All projects in areas not zoned as single family residential that collect runoff from 5 or more parking spaces shall install oil containment catch basins if another approved oil control system is not employed. The outlet pipe of these catch basins shall have a downturned 90 degree elbow to restrict the outflow of oil and other floatables. There should be at least 9 inches of clearance between the elbow and the inside wall of the catch basin to facilitate removal of floatables. A maintenance schedule for the removal of oil and other floatablesfrom these catch basins must be submitted with all plans for review.” j)Pages 6-1 and 7-1–Since this is a Large Site project, a Construction General Stormwater Permit is required from the Department of Ecology.See http://www.ecy.wa.gov/programs/wq/stormwater/construction/for Ecology’s application and other requirements.A Stormwater Pollution Prevention Plan is required by Ecology and will serve to meet the City’s MR #2 for Large Site Projects.Also, please include the Construction Site Sediment Damage Potential form (enclosed) in your submittal to the City. k)Appendix A l)For the modeling, the pervious pavement (modeled as lawn) should be broken down into the amount that is flat ( 0-<5% slope) and moderate (5 to <15%). m)Provide screen shots from WWHM4 of the Rain garden input since the WWHM4 report fails to include important elements such as freeboard, effective total depth, bottom slope, and side slopes. These model inputs are checked against the drawings for consistency.Include a screen shots for the vault input as well. n)The area of the rain garden must be subtracted from the overall basin areas in the “Mitigated” scenario o)Minimum orifice size (including vertical notched) is 0.5 inch to alleviate clogging (ESCS section 4.7.4.2).Reconfigure vault outlets.See enclosed detail of PVC outlet with no shear gate. p)Appendix C. The maintenance instructions should be from the 2005 Ecology Stormwater Management Manual for Western Washington. 2.Plan Sheets Sheet 4.1: The aggregate specification for base course for pervious pavement should be 2.5 inch to 0.5 inch uniformly graded crushed (angular) thoroughly washed stone (AASHTO No. 3) or thoroughly washed, clean Permeable Ballast per WDOT spec 9-03.9(2) (2012) Page 3of 7 Sheet 5.1: Provide a specification for rain garden “Compost amended gravel Loamy Sand” and “Compost amended medium coarse Sand” used in the model so the contractor knows how to build it. Sheet 5.0 or 5.3callout the stormwater pipe materials. Sheet 5.5: If grade permits, a drain pipe (with valve) to empty the water out of the vault during maintenance would be very helpful to the maintenance crews (rather than pump it out). STORMWATER DETENTION VAULT –STRUCTURAL REVIEW Review comments from Peer Review consultant David Evans and Assoc. was provided to you via th email on June 4. Please respond to these comments accordingly. TRAFFIC IMPACT ANALYSIS Approved–no comments. A1.00 –SITE PLAN 1.Please remove specific details regarding theutility systems and simply refer to Civil Engineering plans for engineeringrequirements. LANDSCAPE PLANS 1.The civil plans refer to thelandscape plan for rain garden plantings, but I was not able to find a specific rain garden planting plan in theplan set. Please revise accordingly. 2.Pleaseadd note that states “A separate irrigation permit must be obtained from the City Public Works Department. Prior to final construction acceptance provide the City Cross-Connection Control Specialist with a copy of the backflow test report. Test reports can be faxed to 425.744.6057 or e-mailed to linda.mcmurphy@edmondswa.govBackflow testing will be required on an annual basis thereafter.” SHEET C0.0 –CIVIL COVER SHEET 1.UnderJurisdictions and Utilities –Please add Storm (City of Edmonds) and Phone (Frontier). 2.Where impervious surface area totals are noted, please revise “proposed future conditions” so state something similar to “proposed future expansion”. A slight revisionhere should help identify that the storm system as designed with this phase of the project will be built with excess capacity to account for future building expansion. SHEET C0.1–CIVIL GENERAL & JURISDICTION STANDARD NOTES 1.Under Construction Sequence Notes please add in sequencing for pervious pavementsand rain gardens. 2.Under General Project Notes revise item #6 to state “Coordinate … “ Page 4of 7 SHEET C3.0–TESC AND DEMOLITION PLAN 1.Revise rock construction entrance so rock is located entirely on private property. If the existing curb cut needs to be removed in advance of replacement then a temporary asphalt surface shall be constructed. 2.Please add notes regarding protection of rain garden areas and other protection as needed for pervious pavement areas. 3.TESC legend–please revise the following: a.Temporary Drainage Swale line type should state TS, consistent with the plans. b.Where standard details are noted, please revise COE to state the plan sheet number in which the detail is located. 4.Project Demolition Notes –please revise the following: #5–please provide a response stating where this note is used … I haven’t been able to find it in plan view. #20–please add note that states sidewalk sections shownas “to remain”may need to be removed and replaced as required by Engineering Inspector during construction. C3.1 –TESC DETAILS 1.Revise the title of detail 4 to state drainage swale. C4.0 –CIVIL SITE PLAN 1.Please revise the Civil Site Plan Notes as follows: #5–add standard stall dimensions -8.5’ x 16.5’ #6–add compact stall dimensions –8’ x 16.5’ # 7 & #8 –add stall dimensions #11–reference detail on sheet C4.1 #12–reference appropriate plan sheet for trash enclosure construction detail. #33–Is this note used in the plan set? #46–Is the intent to locate an asphalt speed bump in the same location as the stop bar? #53–Only a partial view of the sight distance confirmation is shown. Please reference plan sheet in which entire sight distance check can be shown or remove from plan set if addressed in traffic impact analysis. 2.Add callout for notes 44 & 45 at north driveway approach. 3.Revise the dimensions of the loading only parking stalls as needed. 5.0’ and 9.7’ does not appear to be accurate. C4.1–CIVIL SITE DETAILS 1.Please revise details to include the plan sheet number in which the detail is referenced. 2.Revise permeable pavement details to include specific standards to be met for rock base and compaction %. See note above under Stormwater Report –Sheet 4.1. 3.Detail 16 –Pre-Cast Wheel Stop: Provide dimension for placement of wheel stop from edge of pavement. C5.0 –GRADING AND DRAINAGE PLAN Page 5of 7 1.Add callout #9 under Grading and Drainage Plan Callout Notes. 2.North rockery -It appears as though the rockery drain is shown on the south side of the rockery. Please revise/clarify accordingly. 3.North rockery –Near the callout for TOP = 409 and BOT = 403, callout note #9 is reference. I believe this should reference #7 (the rockery). 4.Please confirm the stormwater detention systems are designed to accept drainage flows from rockery drain pipes. Typically these pipes are connected to the outfall of the detention system. 5.Add reference to the West Rain Garden Section detail provided on Sheet 5.5. 6.Revise plan sheet as much as possible to only show existing features that will remain and proposed features. For instance, the water meter at the edge of the right-of-way, in alignment with the north side of the building has been called out to be removed, but on this plan sheet it looks as though it will remain in the finished condition. 7.Please revise the Stormwater Drainage Structures Information as follows: ID 1214–please state the size of the existing manhole ID CB02N –If located in rain garden as shown, change to solid lid. ID CB04N –Should this basin have a domed lid? Callout ID YD19S Add information for ID YD20S 8.YD19S is located in a corner landscape planter. Will this planter receive any parking lot runoff through breaks in the curb? If not, is this basin necessary? Is a domed grate appropriate? C5.1 –GRADING DETAILS 1.Please note, the City of Edmonds does not review and approve rockeries. The Edmonds Community Development Code has specific prohibitions that apply to rockery construction, but the City does not have construction standards that are to be adhered to. Please revise the General Notes section to remove reference to City construction requirements. 2.Please revise the Gabion Terraced Wall Section as follows: a.Show the storm pipe crossing below the wall and the required minimum clearance. b.Note that footing drains shall connect to the outfall of the detention system. 3.In the West Raingarden Section, please add reference to detail 2 on sheet C5.5. C5.2–GRADING DETAIL PLANS 1.Revise details that state Northth to read North. 2.The City does not require truncated domes to be installed at driveway approaches or at on site curb ramps. Please revise details accordingly. C5.4 –STORM DRAINAGE VAULT DETAILS 1.Revise notes to callout requirement for polypropylene ladder steps. 2.Detail 1 –the i.e. of the pipe penetrating the wall near the east end of the vault has been called out as 394.90. Per sheet C5.3 it looks like this i.e. should be 392.90. Please revise accordingly. C6.0 –WATER AND SEWER UTILITY PLAN 1.Revise plan sheet as much as possible to only show existing features that will remain and proposed features. For instance, the water meter at the edge of the right-of-way, in alignment Page 6of 7 with the north side of the building has been called out to be removed, but on this plan sheet it looks as though it will remain in the finished condition. C7.0 –FRONTAGE IMPROVEMENTS PLAN 1.The City does not require truncated domes to be installed at driveway approaches or at on site curb ramps. Please revise plans accordingly. 2.The concrete sidewalk along the frontage shall be built to City standards with regards to depth. Sidewalks shall be 5 ½” thick and at driveway approaches 6” thick. 3.Please add note that states sidewalk sections shown as “to remain” may need to be removed and replaced as required by Engineering Inspector during construction. 4.Revise Frontage Improvements Plan Callout Notes as follows: #1–add “as determined by Engineering Inspector” #4 & #7 -curb ramp details are not needed as a callout at the driveway approaches. Instead, please reference and include a driveway approach detail in the plan set –WSDOT F.80.10-02 or COE E2.27.2. 5.Add City Engineering Division approval block. Please contact me at 425-771-0220 or by e-mail at jeanie.mcconnell@edmondswa.govif you have specific questions regarding these plan corrections. Page 7of 7