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• 0 <br /> ii. Sheet 2 <br /> 3. The comments below were generated from this project's Stormwater Reviewer. If you have any questions <br /> regarding these comments, please contact Erik Emerson with the City of Everett Surface Water <br /> Department(425-257-8995 or EEmerson@everettwa.gov). <br /> a. In accordance with Minimum Requirement#9 an Operations and Maintenance manual must be <br /> provided.The maintenance and operation information for the stormwater facilities should be <br /> provided in a separate document entitled "Maintenance and Operations Manual" and must <br /> include a first page indicating the party responsible for maintenance and operation. In addition, <br /> the following language shall also be included in both the M&O manual and the drainage report: <br /> "A copy of the maintenance and operations manual shall be retained on-site or within <br /> reasonable access to the site and shall be transferred with the property to any new owner.A log <br /> of maintenance activities that indicate what actions were taken shall be kept and be available <br /> for inspection by the City of Everett upon request. " <br /> b. The Operations and Maintenance manual should address maintenance procedures for all onsite <br /> stormwater management BMPs, especially the permeable paving system. <br /> c. Figure 3.1.2 Typical Downspout Infiltration Trench in the SWMM downspout infiltration <br /> trenches are to be 24 inches wide and about the same to the bottom of the trench, and parallel <br /> trenches are to be six feet apart.This configuration minimizes groundwater mounding due to <br /> the limited footprint width. While some adjustment to the dimension is reasonable the <br /> configuration submitted diverges too far from the pre-designed template especially taking into <br /> account that the trenches are barely the minimum distance above the anticipated groundwater <br /> elevation and an overflow will drain overland into the neighboring property. Please revise the <br /> infiltration trench design to a configuration which breaks up the footprint of the facility or <br /> provide a groundwater mounding analysis which addresses the impact of the long term function <br /> of the facility. <br /> d. The flow chart included at the beginning of Appendix A indicates that the project will create less <br /> than 5000 SF of new/replaced hard surface which is inconsistent with the rest of the report. <br /> Note that for the threshold determination all new and replaced hard surfaces must be included. <br /> The effective impervious reductions can only be applied for the secondary thresholds associated <br /> with MR 6 and 7.The rest of the report appears to be written to correctly reflect that Minimum <br /> Requirements 1-9. Please update the figure accordingly. <br /> e. Please remove the City's standard detail title block from the permeable pavement section.The <br /> City detail was designed for asphalt and concrete, not the Turf stone product.While some of the <br /> requirements still apply the Turf stone installation should be designed per the manufacturer's <br /> recommended installation and the engineer's professional judgement. <br /> f. The Transition Zone Detail on sheet 2/2 references further specs on Sheet 4. Since there are <br /> only two sheets in the set this would seem to need to be revised. <br /> O3200 Cedar Street © 425.257.8810 O everetteps@everettwa.gov <br /> Everett, WA 98201 425.257.8857 fax everettwa.gov/permits <br /> Page 2 of 2 <br />