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00_Resubmittal Letter.pdf DEVELOPMENT SERVICES - RECEIVED MAY 14, 2018 May 14, 2018 Mike Clugston, AICP City of Edmonds Development Services Department Planning Division th 121 5 Avenue N Edmonds, WA 98020 RE: Edmonds School District Edmonds-Woodway High School Fields – PLN20180014-0017 Response to Letter of Complete Application Dear Mr. Clugston, This letter responds to your April 2, 2018 letter regarding comments on the land use permit requests for the design review, conditional use permit and the two variance requests for updating the fields at Edmonds-Woodway High School. It also addresses the April 13, 2018 Memorandum to you from the Engineering Department and the Stormwater Engineer. Responses were provided by the landscape architect and civil engineer. The following materials are also being submitted: Response letter ...................................................................................................... Original + 1 copy Revised site plans (full size/11 x 17) ............................................................................. 1 copy each Revised electrical drawings (full size/11 x 17) .............................................................. 1 copy each Easement Exhibit (full size/11 x 17) .............................................................................. 1 copy each Images of built improvements ............................................................................................. 2 copies Street view images ............................................................................................................... 2 copies Digital copy of materials on CD ............................................................................................. 1 copy Planning Division Comments 1. Photos, rendering or spec sheets of structures and materials from similar projects including the bleachers, dugouts, fencing, ball control netting, batting cages, lights and light poles. Response:See attached images of built improvements at other project sites. Images include: Backstsops Batting cages (Base Bid) and Batting Cage Building (Alternate Bid) Portable Bleachers - 5 row, 27 ft. portable bleachers Dugout with roof Chain link fencing, black vinyl coated fabric and painted structural posts/framing with selected areas of Ball Control netting DEVELOPMENT SERVICES - RECEIVED MAY 14, 2018 City of Edmonds Planning Division Edmonds-Woodway High School Fields May 14, 2018 Page 2 Field Lighting system including poles, fixtures 2. Visual simulations. Before/after photo simulations looking northeast from near the intersection of 216th Street and 79th Avenue, another looking northwest from near the high school parking lot entrance from 216th, and a third looking southeast from near the proposed javelin area. Response: Site plan and images have been included. 3. Landscaping plan. 'Landscape restoration' areas are shown on Sheet F-1.0 but there is no detail. Please submit a landscaping plan prepared in accordance with ECDC 20.13 showing detail throughout the renovated area of what is being removed and replaced along with compliance with the setback landscaping requirement in ECDC 16.80.030.A . Response: All similar perimeter areas of the high school site include represent occasional trees and a mowed natural turf surface, except at parking lot perimeters which are screened. To be consistent with other areas of the site, deciduous trees are proposed at 25’ OC, complying with the Type IV landscape standard, with a mowed natural turf ground cover. Supplemental large shrubs are proposed to screen the batting cage perimeter. Several supplemental columnar trees are proposed beyond center field of the baseball field to serve as a “batters eye”. The landscape treatment therefore will be consistent with other sports field perimeters of the project site. SEPA Comments It is understood that the Edmonds School District will be acting as the lead agency for the environmental review of this project. The following comments are in response to the project draft Environmental Checklist dated February 2018: 1. Section (B)(7)(b)(2), last sentence. Noise levels must be consistent with the City's noise regulations in Chapter 5.30 (ECC). Sounds originating from league or school sponsored athletic events are exempt from the provisions of ECC 5.30 at all times. Response: The proposed use matches the existing use. Formal use of the field will represent league or school sponsored athletic events, and therefore are exempt from the provisions of ECC 5.30 at all times. 2. Section (B)(8)(h). A City of Edmonds critical area checklist is on file for the site- CRA20180032- which identified potential erosion hazard areas. Response: The critical area checklist identified that there were areas of Moderate topography. No areas of the project area represent steep slopes or erosion hazard areas according to the geotechnical engineer. DEVELOPMENT SERVICES - RECEIVED MAY 14, 2018 City of Edmonds Planning Division Edmonds-Woodway High School Fields May 14, 2018 Page 3 3. Section (B)(11)(d). Per ECDC 17.60.030, sports field lighting must be turned off by an automatically timed mechanism no later than 10:15 pm. Response: Controls will be included in the programmable system to terminate lighting at 10:15 pm. Engineering Comments (with regard to Design Review – no other comments) th St SW as a 60-ft right-of-way. 1. City of Edmonds Official Street Map shows 216 Snohomish County parcel map and the survey provided with the subject application indicate the Edmonds School District parcel extends into this 60-ft right-of-way. The survey contains a note stating “No exception for road contained within the description. Certainly a prescriptive easement exists across the public use”. Existing 216th St SW road and sidewalk improvements appear to built within the “60-ft ROW” and the project proposal appears to take setbacks from this “ROW” line. As a condition of building permit approval, a right-of-way dedication should be recorded to clear up any right-of- way/parcel boundary discrepancy that may exist. Response: Agreed. 2. Revise plans to show replacement of corner curb ramps at high school driveway approach off 216th St SW. Response: Agreed. 3. Please provide a document that clearly shows easements encumbering the property in order to confirm that none of the improvements proposed extend into the easement areas. Information provided on the survey is difficult to read and it appears there are additional easements that have not been shown on the survey. Easements referenced on City maps and/or the survey include the following: AFN2027844 – ST 10’ AFN1994515 – SS 10’ AFN1914233 – ST 10’ AFN9806030206 – UTILITY and PED DEVELOPMENT SERVICES - RECEIVED MAY 14, 2018 City of Edmonds Planning Division Edmonds-Woodway High School Fields May 14, 2018 Page 4 Response: See attached supplemental easement exhibit, indicating AFN 2027844, 1914233 and 9806030206. AFN 1994515 is on tax lot 1063, and not on the district site. Stormwater Comments(regarding Design Review only - no other comments) 1.Itis stated in the report that areas treated with BMP T.13 (amended soils) are not considered converted vegetative surfaces, but this is not entirely correct as noted below; update repot/plans as needed to clarify which areas should be considered converted and correct impacts to the design as needed. a. For the requirementsofMR #5, areas treated with BMP T5.13 do not require further consideration for that particular requirement; other minimum requirements, includingflowcontrol,must still be designedperthemanual. Response: Noted. b. Therefore, the definition of converted vegetation must be used which speaks specifically to native vegetation: i. Areas which are replanted with native vegetation with amended soils, do not need to be considered converted vegetation. ii. Any area which is not replanted with native vegetation does need to be considered converted vegetation and compared to forested conditions. DEVELOPMENT SERVICES - RECEIVED MAY 14, 2018 City of Edmonds Planning Division Edmonds-Woodway High School Fields May 14, 2018 Page 5 Response: The review comment is somewhat at odds with Planning Department requirements for Type IV landscape treatment. We propose to modify the soil, including the addition of organic amendment, and subsequently plant trees and natural turf at the ground plane to restore to existing conditions.It would not be possible restore existing grass areas with native vegetation. Therefore, these disturbed pervious areas will be counted as forested in the predeveloped condition of the stormwater model. Increase in target surface and detention system will be noted in the project’s revised drainage report. c. The report is correct in that run-on areas which are not disturbed by the project (ie. not within project limits) may be modeled the same for historic conditions and developed conditions. Response: Noted. Disturbed pervious areas outside of the tributary flow control basins were modeled as grass to grass. 2. It is not clear that the application of LID BMPs, per ECDC 18.30.060.5 and MR#5, has been adequately addressed. a. The geotechnical report appears to only provide a qualitative conclusion that soils are “slow draining”; revise report to include all information leading to conclusion that infiltration is not recommended Response: We do not recommend infiltration at this site. Based on the exploration logs, grain size data and our experience with similar glacial till soils, infiltration rates would be significant lower than 0.3 in/hr due to the high density and relatively high fines content of the native glacial till and indicators of perched groundwater (oxidized soil horizon and scattered seepage zones). i. Soils grain analysis is discussed in body of report, but results and data do not appear to have been not been provided Response: We have grain size data from exploration boring EB-6 (AESI 160257E001) and from work in 2014 for the portables (AESI 140482H001) that shows the glacial till is dense and silty to very silty. b. Permeable pavements are infeasible if measured rates are below 0.3 inches per hour; provide additional information as needed to verify that pervious pavement are feasible and should receive modelling credit as assumed. Response: Although civil design includes permeable walkways in/around the field area, from our review of the drainage report, it appears that no infiltration ‘credit’ was DEVELOPMENT SERVICES - RECEIVED MAY 14, 2018 City of Edmonds Planning Division Edmonds-Woodway High School Fields May 14, 2018 Page 6 assumed. Design assumes water soaking into permeable base course would be collected with field drainage pipes and routed to detention facility. Per coordination with the geotechnical engineer, the 0.3 inches per hour measured infiltration rate could not be met. Therefore, permeable pavement is not feasible as a BMP. i. Expand text as needed to explain why “infiltration is not recommended” but infiltration via pervious pavements is allowable. Response: See response to 2b regarding why infiltration is not recommended. c. As noted below, field condition is not considered application of an LID BMPs as proposed; accordingly, assess feasibility of bioretention for the field basin and/or expand description of infeasibility. Response: Permeable pavement is not feasible as a BMP. However, it will be used with proposed underdrains to create drainage conditions similar to the proposed field. This will provide slower runoff rates than standard pavement would. On-site stormwater management (OSM) descriptions will be revised in the updated drainage report. 3. Remove all references to the field as an LID BMPs “similar to pervious pavements”; if field is to be used as a BMP, it would need to follow the guidelines for modelling per Part 1 of Appendix III-C. Response: We were not intending to use the field itself as its own on-site stormwater management BMP, although this premise has been accepted by multiple jurisdictions. It was just intended to show the field system hydraulically functions similar to permeable pavement, thus meeting the intent of on-site stormwater management BMPs. Since this is not acceptable, references to the field system in the descriptions of on-site stormwater management have been removed. 4. It is not clear that the project areas fully meet the retrofit requirement of ECDC 18.30.060.5.b.i for MR #5. Response:The existing hard surfaces to remain that are within the project disturbance area are mitigated. A clause in the revised drainage report has been added for clarification. For the existing tennis courts that will remain, the existing storm system will remain, which collects those surfaces and route them to the mitigation systems in the existing parking lot to the east of the project area. a. Provide information and delineation of existing surfaces which may already be mitigated by existing facilities. Response: See response to #4. DEVELOPMENT SERVICES - RECEIVED MAY 14, 2018 City of Edmonds Planning Division Edmonds-Woodway High School Fields May 14, 2018 Page 7 b. Revise plans and report as needed to apply MR #5 to 25% of currently un- mitigated impervious surface on the site. Response: See response to #4. 5. Provide additional information for how the field detention stage-storage information was determined for the inputs in MSGS; I understand that the included spreadsheet calculates the total volume of the system (and is believed to be correct in that regard), but it is unclear how the stage-storage relationship was determined from this information. Response: Stage storage excel spreadsheets for both the field drainage system and StormTech chamber system will be sent to the City for their review. Please let LPD know if there are any questions regarding the stage storage spreadsheets. 6. The field basin detention design will retain water up to 416.80 and will result in occasional standing water above the rim elevations of the CBs 4, 5, & 6. Updated design as needed or update report to acknowledge and address this condition. Response: This has been discussed with City reviewer. The field is designed to pond water up to 416.80, which will be above the rims of the mentioned catch basins. The structures are placed in graded low spots to account for this condition. 7. Identify each of the control structure details on F-2.5 by the corresponding CB numbers. Response: Added to Plan. 8. The drainage report does not state what the turf and infill materials will be; explicitly state what turf and infill material will be used and address potential water quality impacts of the material. Response: At this time, the “exact” product or vendor is not known and will not be able to be confirmed until after bidding. However, the specification intent is to provide a long parallel, slit film type fiber with a perforated/permeable backing coated with polyurethane, as follows: Specification Section 32 18 24, 2.11A A.Pilefibershallbealongparallelslitfilmfibrillatedtapefiber,100%polyethyleneathletic qualityyarndesignedspecificallyforoutdooruseandstabilizedtoresisttheeffectsof ultravioletdegradation,heat,wear,waterandairbornepollution.Thefibrillationshallbe parallelwithlongslits. DEVELOPMENT SERVICES - RECEIVED MAY 14, 2018 City of Edmonds Planning Division Edmonds-Woodway High School Fields May 14, 2018 Page 8 Pile height will be approximately 2.0-2.25” and will have a supplemental pad installed below the turf. Infill will be bid with a base condition and alternate condition. The base bid will include a combination of sand and SBR rubber per district standard. The alternate bid will include a combination of sand and natural cork. The infill materials are essentially inert, however all surface water from the field will be collected and passed through a water quality filtration system per drawing details. a. Turf material must be “lead-free”, including the paint/coloring. Response: Turf Specifications will indicate to be lead free, per the following: Specification Section 32 18 24, 1.04D 5͵Fibershallbecertifiedtohavelessthan50ppmorlessofleadfromboththefibersupplier andtheturfvendor. Specification Section 32 18 23, 2.12H – Infill I͵Regardlessofsourceortype,Infillshallbecertifiedtohavelessthan50ppmorlessoflead fromboththesupplierandtheinfillvendor. 9. Update Figure 5 (proposed conditions model areas) to: a. Identify and show limits of all/each bypass basin(s). b. Identify the roofs with separate hatching and quantities than the field surface. c. Identify with appropriate hatching, and provide a quantity for all areas which are to receive the amended soils treatment per BMP T5.13 (ie. grass and landscape beds). d. Identify and show limits of the run-on areas which do not require mitigation. e. Update field footprint acreage to 2.69 (to match SF listed). Response: Noted. Bypass areas are delineated with dashed line instead of solid line. Roof areas are shown on Figure 4, but they have now been added to Figure 5 as well. Disturbed pervious areas have been hatched and identified for clarity. See Figure 4 for run-on that does not require mitigation. The typo for field acreage has been corrected. Prior ConstructionApproval: The following comments were noted by the reviewer as issues that will require revision prior to construction approval, but do not necessarily required attention prior to feasibility approval. DEVELOPMENT SERVICES - RECEIVED MAY 14, 2018 City of Edmonds Planning Division Edmonds-Woodway High School Fields May 14, 2018 Page 9 A.Nyoplast catch basins do not provideman/ladderaccess and may not be usedat locations where rim to invertmeasures greater than 5’(unlessalternativeaccessis provided);reviseas needed. Response: This has been discussed with City’s reviewer. These nyloplast basins are not for access, as the StormTech chambers require vactor cleaning of the system for maintenance. The StormTech chambers are not a confined space. BIt unclear why an “underdrain”isprovidedaround thestorm chamber system; theunderdrainisconnected to the controlstructure CBsoit will detain water and runoffwill backwater the underdrainsystem, providing no relieffrombuoyancy. Response: According to correspondence with ADS (StormTech Manufacturer), the function of the underdrain is to allow the system to drain completely when storm event subsides or within 48 hours. Hydraulically, as ponding increases within the system, the underdrain will be full and storage will still be utilized within the system, with release rates controlled by the flow control structure. a. The underdraincannot bypass the controlstructure as the current location configurationwouldallowflowsin the detentionsystem toflowdirectlytothe underdrain, rather than beingdetained and released through controlstructure. Response: Piping has been adjusted to achieve minimum cover in this area. C. The connection to CB #13 appears to have less than 2’ofcover to the bottom of pavement in a traffic rated location;reviseas needed toachieve2’minimumcover provideductileironpiping. or Response: System design has been modified to provide minimum 24” cover, matching existing conditions. If you have any questions or require additional information, please do not hesitate to call me at (425) 258-9308. Sincerely, S HOCKEY P LANNING G ROUP,I NC. Camie Anderson Senior Associate Enclosures: As Previously Detailed cc: Nick Chou