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HomeMy WebLinkAbout2011-09-06 Planning Board Supplemental Materials (66) Eggleston Environmental 32 Old Framingham Rd Unit 29 Sudbury MA 01776 tel 508.259.1137 fax 866.820.7840 August 2, 2011 North Andover Planning Board 1600 Osgood Street North Andover, MA 01845 Attn: Judy Tymon, Town Planner RE: Stormwater Management Review 1679 Osgood St. & Bradford St. Dear Ms. Tymon and Board Members: In follow-up to my January 27, 2011 and previous review letters on the above-referenced project, I have received and reviewed the July 8, 2011 response letter, June 30, 2011 revised plans (Sheets A1, A4, C4, C5, C6, and D4) and June 30, 2011 revised Drainage Analysis, Sediment and Erosion Control Plan and Stormwater Pollution Prevention Plan from Jones & Beach Engineers, Inc. The revised submission addresses a number of the issues expressed in my previous letters, and incorporates an additional “outlet pond” infiltration basin in the design to reduce the discharge from the gravel wetland to below pre-development levels. It also includes the addition of Lot 31 to the subdivision design, and provides drainage for that lot. I am at this time satisfied that all of my previous comments regarding the drainage system design have been adequately addressed. My remaining comments, focused on construction and maintenance issues, are outlined below: 1. Note 10 on Sheet A1 states that the homeowner’s association (HOA) will be responsible for the long-term maintenance of all drainage structures outside of the roadway ROW, and that all lots are to have deed restrictions stating this fact. The revised O&M Plan, however, indicates that the Town will be responsible for maintaining the gravel wetland, infiltration basins, sediment forebays and vegetated areas of the development, and the proposed deed language only addresses the bioretention systems. Both the O&M Plan and the proposed deed language should be revised to be consistent with Note 10. 2. Note 14 on Sheet A1, prohibiting filling or re-grading of the bioretention systems/rain gardens, should also be included in the deed restriction. The language currently proposed only addresses maintenance of the basins. 3. While it may be appropriate for individual homeowners to maintain the roof infiltration systems and rain gardens, I believe that the maintenance of the gravel wetland, infiltration ponds and sediment forebays should be conducted by professionals under contract to the HOA. The Board should ensure that such contracts are in place prior to bond release. 1679 Osgood Street, Technical Review 2 August 2, 2011 4. As indicated previously, this project entails the disturbance of more than one acre of land and is therefore subject to the Construction General Permit issued by EPA. The Applicants have provided a draft Construction Stormwater Pollution Prevention Plan (SWPPP) in one of the earlier submittals. It is expected that the SWPPP will be finalized when a contractor has been selected and an NOI is filed for coverage under the permit, and updated as construction progresses. I recommend a pre-construction meeting between representatives of the Planning Board and Conservation Commission and the contractor to discuss implementation of the SWPPP. The Board should also consider requiring an independent Environmental Monitor for the project. 5. The June 30, 2011 revised Drainage Analysis, Sediment and Erosion Control Plan and Stormwater Pollution Prevention Plan should be treated in the record as a supplemental document and not to replace the July 12, 2010 version in its entirety. Several important items, including design calculations and the draft SWPPP, are not included in the copy of the June 30th revisions that I received. Once again, 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 Lisa D. Eggleston, P.E. C: Jennifer Hughes, North Andover Conservation Commission