Laserfiche WebLink
PUBLIC WORKS <br />■ Provide detailed design drawings showing the required flow spreader, <br />erosion protection, geotextile fabrics, ventilation grate, access for <br />maintenance, etc. See the detailed criteria for design, construction, <br />and maintenance of BMP T8.20 in the SWMM. <br />■ Document whether storage in the detention system would back up or <br />impede performance of the sand filter vault during large storms. Base <br />the assessment and discussion of this on the WWHM modeling results <br />for the range of flows modeled. <br />■ Demonstrate how the sand filter design will provide maintenance <br />access and meet the anoxic conditions prevention requirements for <br />vaults (BMP T8.10) <br />4. Consider adding a berm (e.g., asphalt) at the down gradient side of the <br />SDMH#6 to improve collection and routing of stormwater runoff to the sand <br />filter. <br />• MR #7 — Flow Control: <br />1. The Detention Sizing Note and Bypass Note indicate that the proposed <br />designs do not meet the flow control standard. The designs must be revised to <br />meet the flow control standard, including proper consideration of off -site <br />flows and bypassed flows, and the documentation must be updated to <br />demonstrate that the standard is met. <br />2. See the notes for Sheets 5 and 6 below, and update the detention system <br />design and documentation accordingly. Include all tributary area in the sizing <br />calculations, including any off -site run-on. <br />• MR #9 — Operation and Maintenance: <br />1. Update the O&M Manual as follows: <br />Include the complete list of maintenance activities for BMP T5.13 <br />Post -Construction Soil Quality and Depth. <br />■ Add the sand filter maintenance criteria for BMP T8.10. <br />Update the sand filter maintenance information based on design <br />updates per the comments in MR #6, as applicable. <br />b. Design Plans: <br />• Sheet 5 — Road, Drainage, & Utility Plan & Profiles: <br />Include required notes from Section 4-2.7, Volume I of the DCSS. <br />2. The Plan View call -out for the "linear sand filter" refers to a detail on Sheet <br />6, but the detail is not provided on Sheet 6. The call -out should indicate the <br />correct BMP type (e.g., sand filter vault) and the detail needs to be provided. <br />3. Show the required setback from the property line in the Plan View. _ <br />Page 5 of 6_ <br />