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pln20120021-Ritter-Civil-E1-revised.pdf CITY OF EDMONDS CIVIL PLAN REVIEW COMMENTS ENGINEERING DIVISION (425) 771-0220 City Website: www.edmondswa.gov DATE:May 15, 2013 May 23, 2013 -revised TO:Carl Clapp, CC Construction carclp@comcast.net FROM:Jeanie McConnell, Engineering Program Manager RE:Subdivision File #: pln20120021 Project: Ritter, 3-lot Short Plat Project Address: 8364 Olympic View Drive During review of the above noted application, 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 an Engineering Technician. City of Edmonds handouts and standard details can be referenced on the City website under Permit Assistance. 5/23/2013 –The following document has been revised to include review comments from the Planning Division. 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 all utilities, traffic control, and restoration/enhancement plantings. Please use the King County Site Improvement Bond Quantity Worksheet and utilize the “write-in” sections where appropriate. A bond is required to be placed for all erosion control measures, right-of-way and stormwater management improvements. Posting a bond for stormwater systems applies to subdivisions that involve 7,000 square feet or more of land disturbing activity and as well as on projects in a critical area or buffer including ESLHA. The amount of the bond will be based on 120% of the City approved estimate. The City will inform you of the appropriate bond amount after review of the cost estimate. Please obtain the appropriate subdivision improvement bond forms from the City. If you intend to post a bond in order to record the subdivision, the bond amount will be based on the entire scope of the project. Inspection fees for this project will be calculated at 2.2% of the 120% City approved estimate for all improvements. 2.Please submit a traffic control and haul route plan for review and approval. 3.Please add a general note to pertinent plan sheets that states: “Approval of these plans does not constitute approval of the single family residences and associated setbacks. A separate building permit is required for review and approval of the single familyresidences. 4.The attached ROW construction permit shall be completed, with contractor’s signature, and provided to the City prior to civil plan issuance. 5.Add reference to City subdivision file number –PLN20120021 6.A couple of trees proposed for removal areshown to be located within the City right-of-way. Please provide documentation showing these trees will not provide marketable timber. If the timber is marketable, the money provided to the owner/developer for removal of the tree(s) will need to be paidto the City. PLANNING DIVISION COMMENTS 1.Sheet C-1 indicates “temporary chain link fencing for tree protection” surrounding the southern side of the future building pad area on Lot A.Since no work associated with the civil improvements is proposed to occur within the future building pad area on Lot A, the temporary construction fencing should be located further north (i.e. near the northern side of the future building pad on Lot A) as indicated on Sheets C-1.1 and C-3.Revise all plan sheets as necessary to indicate consistent locations of the clearing limits and temporary construction fencing. 2.Please remove the height calculations from Sheet C-3 since the future home on Lot A is not being reviewed at this time.The height calculations will be reviewed for compliance with applicable zoning regulations at the time of building permit application review. 3.Retaining walls shall not exceed three feet in height as measured over original grade.It appears that top of wall elevations were provided for the northern wall on the detail on Sheet C-3; however, these numbers are not labeled, so it is unclear what they are referring to.Please provide and label top of wall elevations on both proposed retaining walls at five-foot intervals in order for staff to confirm compliance with the setback requirements for both of the proposed walls. 4.Since much of the site contains a Landslide Hazard Area, this phase of the project will need to be reviewed by a qualified geotechnical engineer pursuant to ECDC 23.40 and 23.80.Please provide a letter by a qualified geotechnical engineer that addresses how the proposed work associated with the civil improvements, tree removal, and vegetation management plan is consistent with the critical areas regulations of ECDC 23.40 and 23.80 and providing any additional recommendations for what would need to be done in order to comply with the critical areas regulations and avoid any potential negative impacts to the stability of the slope. 5.Add the following statement to the plan sheets that indicate the existing trees to be retained: “All trees that are indicated to be retained must be protected during construction of the civil improvements according to the performance standards of Edmonds Community Development Code (ECDC) Section 18.45.050.H.” 6.Thank you for indicating the boundaries of the required 30% native vegetation area on Sheet C- 1.1.Additional information, however, is needed in order to show compliance with the native vegetation requirements of ECDC 23.90.040.C.Please provide written documentation (either as notes on Sheet C-1.1 or as a separate document) addressing the following: a.An “NGPA” typically refers to an area that is formally established with the recording of a subdivision or other easement documentation.Since it is not required that this area be formally established as an NGPA, please remove all references to the NGPA, and instead refer to this area as a native vegetation area (unless it is the owner’s intention to Page 2of 5 formally establish this area as an NGPA).This will avoidany potential future confusion as to whether this area was formally set aside as an NGPA/easement. b.Describe the vegetation that is currently present within this area, including descriptions of what existing vegetation is native, non-native, or invasive. c.Describe what work is needed in order to remove any existing non-native or invasive species from within this area (if any non-native or invasive species are currently present within this area). d.Describe what work is needed to establish this area as exclusively native vegetation (i.e. addition of native groundcover, shrubs, or trees in order to replace any non-native or invasive species that must be removed). If any planting is necessary in order to establish this area as exclusively native vegetation, provide the species, sizing, and installation instructions. e.Include provisions for maintenance of the native vegetation area into the future (i.e. how will this area be maintained into the future, what will be done for control of invasive species, how will any vegetation that requires removal in the future be replaced?) f.Include a reference that all maintenance activities and/or vegetation cutting must be consistent with the applicable provisions of the tree cutting code (ECDC 18.45) and critical areas code (ECDC 23.40 through 23.90), or as amended. g.Include provisions for how any future changes to the boundaries of the native vegetation area or to the vegetation management plan could be made if so desired by the current or future property owner(s). DRAINAGE REPORT dated March 19, 2013 1.The report should include the area of land-disturbing activity and the amount of grading, filling or excavation.These numbers are evaluated against regulatory thresholds to determine project requirements. 2.Basedon the information presented, the site is a Category 2 Small Site and has allowable discharges of t 0.07 cfs/impervious acre, 0.14 cfs/impervious acre, and 0.33 cfs/impervious acre for the 2-yr, 10-yr and 100-yr recurrence event, respectively.These allowable discharges are only for catchment areas 5,000 square feet or greater. By using 2 catchment areas smaller than 5,000 sf (3,654 sf and 4,337 sf) it is not possible to meet the 2-yr standard without having a low flow orifice smaller than 0.5 inches.Due to clogging concerns, the minimum orifice size is 0.5 inches (Edmonds Stormwater Code Supplement, Section 5.7.4.2). One detention system serving both lots A & B with 7,991 sf of impervious will be able to meet all standards, including the 2- yr without having an orifice too small.This should go in the shared driveway that serves both lots. 3.The WWHM modeling should use the DOT precipitation set for “Puget Sound 36” instead of the Everett gauge data (Edmonds Stormwater Code Supplement, Section 5.7.3.1) 4.All disturbed pervious areas must have compost-amended soils per the City standard http://www.edmondswa.gov/images/COE/Services/Permits_and_Development/Forms_and_Han douts/E72_C-Compost_Amended_Soils--06.06.11-FINAL.pdf 5.All storm drainage pipes should connect at a catch basin or yard drain, as appropriate. Page 3of 5 SHEET C-0–PRELIMINARY PLAT 1.Add “Approved for Construction” signature block 2.Please note easements and associated recording numbers in bold line type on this plan sheet. 3.Please note existing buildingsand other features as “to remain”or “to be removed”. SHEET C-1–TEMPORARY EROSION AND SEDIMENT CONTROL PLAN 1.The rock construction entrance as shown leaves good potential for quarry spall rock to be kicked out onto Olympic View Drive during construction. Please revise to show a 5-10’ temp asphalt apron between the rock construction entrance and the travel lane. 2.In the Utility Contacts section, please state City of Edmonds for water, sewer and storm utilities and remove reference to Olympic View Water and Sewer District. 3.Provide a Plan Sheet Index SHEET C-1.1–TREE RETENTION/NGPA PLAN 1.Revise hatching so driveway surfaceand NGPA areas are shown differently. 2.Revise approval block on this sheet to state City Planning Division instead of Engineering. SHEET C-3–GRADING PLAN AND DRIVEWAY & FRONTAGE IMPROVEMENT PLAN 1.A lot of information has been provided on this plan sheet and it is difficult to identify pertinent details. Please use a darker line type for pertinent items and a lighter line type for more informational typeitems. 2.Revise hatching so driveway surface and NGPA areas are shown differently. 3.Provide cross sectionthat shows drivewaysurface and retaining wall. If any surcharge is placed on the retaining wall the wall shall be designed by a licensed engineer with calculations submitted to the City. 4.Please revise note on plans that states the fogline will be restriped as needed to also include the centerline of OVD. 5.A 2-foot sawcut is not required along the edge of pavement with a proposed asphalt driveway surface joining up to the existing asphalt travel lane. 6.Revise profile to be specific to driveway centerline grade and move utility system profile to utility sheets. 7.Please show the trench patching required for the storm crossing and refer to City standard detail E2.3 for typical HMA and Utility Patch requirements. 8.The driveway has been designed with a 19.9% slope. City code allows for a maximum14% slope, with the potential to receive a waiver up to 20% with noticingas a Type II land use decisionand approval by the Public Works Director. Please refer to ECDC 18.80.060.D and revise plans or respond accordingly.If you choose to proceed with a driveway slope design of over 14%, please reduce the slope below 20% as much as feasible. A design at almost 20% leaves no allowance for adjustments during construction. 9.Clearly show existing asphalt drive servicing existing lot. Add anote that no changes to the existing access are proposed. Page 4of 5 10.With regards to the mailbox, please note that the location shall be approved by the postmaster. The note as written could be interpreted to mean the post master is installing it. SHEET C-4–DRAINAGE PLAN 1.Please use a darker line type for pertinent items and a lighter line type for more informational typeitems and other utility systems. 2.All utility systems with over 20% slope shall be anchored in place. Clearly identify those sections that need anchoring and provide appropriate details. 3.At the storm crossing on Olympic View Drive, a catch basin shall be provided at the edge of pavement on the south side of OVD and then cross over to proposed CB#3 on the north side. 4.Storm pipe within the City right-of-way shall be 12” in diameter.If 2-feet of cover cannot be achieved the ductile iron pipe shall be used. Please revise plans accordingly. 5.Please identify storm pipe material throughout. 6.Verify catch basins in plan view are numberedthe same as the basins in profile view. 7.For clarity, please noteimpervious surface areas for each lot (with a breakdown for driveways, walks, etc.), as well as for the total site in a table format instead of labeling areas in plan view. SHEET C-5–WATER AND SEWER PLAN 1.All utility systems with over 20% slope shall be anchored in place. Clearly identify those sections that need anchoring and provide appropriate details. 2.Please confirm separation between the water service line and proposed storm system can be met at each of the crossings. 3.Per City ordinance, homes with 3000sf or more habitable space shall be sprinkled for fire protection. When this is required a flow through system is typically installed and the minimum meter size will need to be 1”.Please revise plans as needed. 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 5of 5