Loading...
HomeMy WebLinkAboutConsultant Review - 100 CHADWICK STREET 1/3/2014 Eggleston it l January 3,2014 North Andover Planning Board 1600 Osgood Street North Andover, MA 01845 Attn: Judy Tymon, Town Planner RE: Stoixnwater Review McEvoy Field Dear Ms. Tymon and Board Members: Per your request, I have reviewed the December 6, 2013 Special Permit Application for packet for the above-referenced project. Included in the materials I received and reviewed were the following: • Stormwater Management Plan, McEvoy Field, Town of North Andover, prepared by Waterfield Design Group and dated December 6,2013. i • Site Plans (11 Sheets), Redevelopment of McEvoy Field, 100 Chadwick Street, North Andover, prepared by Waterfield Design Group and dated December 6, 2013. • Stormwater Pollution Prevention Plan and Erosion and Sediment Control Plan, McEvoy Field, Town of North Andover, prepared by Waterfield Design Group and dated December 6, 2013. • Operation and Maintenance Plan, McEvoy Field, Town of North Andover, prepared by Waterfield Design Group and dated December 6,2013. The proposed project is the redevelopment of the existing town field facility to provide reconfigured playing fields, a children's playground, a concession stand with restroom, picnic area, and a gravel driveway and parking area. As proposed, the new playing fields will be equipped with underdrains to enhance drainage, and the playground/concession stand area will drain to an onsite bioretention area. A grassed Swale along the western edge of the property will convey excess drainage to a drain inlet at the northwest corner and into the existing municipal drain line in Sutton Street. In addition, the paved parking area along the edge of Sutton Street will be removed and replaced with a stone diaphragm and grassed swale, which will drain through a new area drain into the existing municipal drain line. My comments on the application are outlined below: 1. In accordance with the Site Plan Review requirements, the Stormwater Management Plan includes drainage calculations demonstrating that there will be 32 Old Framingham Rd Unit 29 Sudbury MA 01776 tel 508.259.1137 fax 866.820.7840 McEvoy Field, Stormwater Review 2 January 3, 2014 no increase in runoff from the site under the 2, 10 and 100-year design storm events. 2. The proposed project also incorporates low impact development(LID) techniques to maximize groundwater recharge on the site and to provide water quality treatment of runoff"to the maximum extent practicable". 3. The play surface underdrains should connect to underdrains beneath the bioretention area,not to the basins themselves as the note on Sheet L-3 suggests. 4. The bioretention area detail on Sheet D-4 should show underdrains beneath the system and the overflow area drain with a direct connection to the underdrains, as well as the proposed grading for the basin. The underdrains should be in a stone layer beneath the bioretention soil. 5. I recommend a bioretention soil mix similar to that specified in the DEP Stormwater Handbook (40% sand, 30-40% compost, 20-30% topsoil) rather than the loam specified on Sheet D-4. 6. The 12-inch ponding depth called for on the bioretention system detail is inconsistent with the spot grades shown on Sheet L-4 (showing a low point of 148.5 in the basins) and the rim elevations of area drains #1 and 2 (149.0) shown on Sheet D-6. 7. The inlet and outlet inverts for area drain#2 are incorrectly listed in the detail on Sheet D-6 as 138.0. I believe both inverts should be 148.00. 8. I note that the existing catchbasins in Sutton Street are located directly on the drain line, rather than in an off-line configuration. Hence, any sediment that accumulates in the catchbasins is prone to washout. Rather than adding a new area drain connection to the existing drain line and a new drain connection to the existing catchbasin in Sutton Street as is proposed, consideration should be given to converting the existing catchbasin to a manhole structure and adding a new off- line catchbasin. 9. As indicated on the Stormwater Checklist, this project entails the disturbance of more than one acre of land and is therefore subject to EPA's NPDES Construction General Permit (CGP). A draft Stormwater Pollution Prevention Plan (SWPPP) was submitted with the application. This plan should be finalized in conjunction with the selected site contractor prior filing of a Notice of Intent under the permit and initiation of work on the project. 10. The stabilized construction entrance should use minimum 2"diameter stone. 11. The O&M Plan should include periodic maintenance of the crushed stone diaphragm along Sutton Street. McEvoy Field, Stormwater Review 3 January 3, 2014 12. It is unclear whether the stone driveway and parking area would be plowed in the winter. If so, snow storage on the site should be addressed. I appreciate the opportunity to assist the North Andover Planning Board with the review of this project, and hope that this information is suitable for your needs. Please feel free to contact me if you or the applicants have any questions regarding the issues addressed herein. Sincerely, EGGLESTON ENVIRONMENTAL v �S Lisa D. Eggleston, P.E.