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HomeMy WebLinkAbout2013-06-18 Planning Board Supplemental Materials (29) Eggleston Environmental 32 Old Framingham Rd Unit 29 Sudbury MA 01776 tel 508.259.1137 fax 866.820.7840 May 20, 2013 North Andover Planning Board 1600 Osgood Street North Andover, MA 01845 Attn: Judy Tymon, Town Planner RE: Stormwater Review 1665 Great Pond Road WSP Dear Ms. Tymon and Board Members: Per your request, I have conducted a technical review of the March 28, 2013 Watershed Special Permit Application packet submitted by Andover Consultants, Inc. for the above- referenced project. Included in the materials I received and reviewed were the following: § Watershed Special Permit Application, 1665 Great Pond Rd Lot B, Technical Training Foundation Trust, Petitioner, prepared by Andover Consultants, Inc. and dated March 28, 2013. § Site Plan, Great Pond Road, prepared for Technical Training Foundation Trust by Andover Consultants Inc. and dated March 28, 2013. My primary focus in this technical review is on the overall stormwater management approach and design concepts used in the project, as well as its compliance with the Town of North Andover’s zoning requirements for Watershed Protection Districts, the Massachusetts Wetlands Protection Act and Regulations, and the North Andover Wetlands Bylaw. It is my understanding that either a Notice of Intent (NOI) application or an Abbreviated Notice of Resource Area Delineation (ANRAD) has been or will be filed with the Conservation Commission for this project. My review is aimed at assisting both the Planning Board and the Conservation Commission in their respective reviews of the project. The proposed project entails the construction of a single family home and driveway on a mostly vacant lot. The lot is wholly within North Andover’s Watershed Protection District, and portions of the lot are also within the buffer zone of regulated wetlands. My comments on the proposed plan are outlined below: 1. The proposed development activity is located within Non-Disturbance and Non- Discharge Zones of the Watershed District. It is my understanding that this lot was created before October 24, 1994, hence the limitations of the General Zone of the Watershed Protection District regulations do not apply. As shown, the project includes clearing, grading and construction of a paved driveway and associated 1665 Great Pond Rd WSP, Stormwater Review 2 May 20, 2013 drainage structures within the Non-Disturbance Zone and construction of a new house within the Non-Discharge Zone. Regrading and vegetation removal are allowable in the Non-Disturbance Zone only by Special Permit. Construction of a new permanent structure within the Non-Disturbance Zone is also allowed only by Special Permit and only after a variance has been granted by the Zoning Board of Appeals. I believe that a driveway would be considered a permanent structure under the Town’s Zoning Bylaw; therefore a variance from the ZBA is needed for this project. 2. The boundaries of these buffer zones are based on the horizontal setback from the edge of all wetland resource areas as defined by the Wetlands Protection Act and the North Andover Wetland Bylaw. It is not clear whether the wetland boundaries shown on the plan have been confirmed by the Conservation Commission, e.g. through an ANRAD or NOI. 3. The Plan should also show the Zone A for the Lake Cochichewick public water supply, defined by the Massachusetts Drinking Water Regulations (310 CMR 22.02) as including the land area within a the land area within a 400 foot lateral distance from the upper boundary of the bank of a Class A surface water source and 200 foot lateral distance from the upper boundary of the bank of a tributary or associated surface water body. 4. The Plan should show the proposed edge of vegetation clearing/limit of work. While much of the proposed development area is already cleared, the creation of any new lawn or landscaped area should be limited to that which is absolutely necessary and constructed in such a manner as to minimize the maintenance that is required, e.g. the soil should be well aerated, it should have a minimum of 6- inches of topsoil and, where possible, native vegetation should be planted to minimize the need for fertilizer and watering. The Planning Board may also want to request a planting or landscape plan for the property. 5. As with similar projects permitted within the Watershed Protection District, both the limits of approved clearing and the Board’s standard restriction on lawn care products should be permanently recorded on the deed to the property. 6. The narrative indicates that roof runoff from the proposed house will be directed onto lawn areas for infiltration; however it is not clear from the plan how this is to be accomplished. 7. The plan calls for driveway runoff to drain to a stone trench along the northern edge of the driveway, which in turn drains to a 60-ft flat swale at the base of the driveway (within the 100-ft buffer zone). The plan also calls for a 8-in overflow pipe from the swale under the driveway, discharging toward Great Pond Road. It is not clear why this overflow pipe is needed, as the trench and swale should be designed to handle all of the runoff from the proposed driveway. 1665 Great Pond Rd WSP, Stormwater Review 3 May 20, 2013 8. Given its nearly 10 percent grade, I recommend adding check dams in the stone trench to slow the rate of flow and promote infiltration. 9. A design detail for the proposed swale is needed. Given its proximity to wetland resource areas and the town’s water supply the swale should be designed to maximize water quality treatment and promote infiltration, e.g. incorporating a bioretention area with an overflow swale. 10. Ongoing maintenance and preservation of the proposed stormwater management structures should be addressed. I appreciate the opportunity to assist the North Andover Planning Board and Conservation Commission 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, Conservation Coordinator