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HomeMy WebLinkAbout2016-04-05 Stormwater Review 2=2016 Town of North Andover Mail-1665 Great Pond Road-Revised Plan/Response to Comment NO Q,0VER Massach .lean Enright<jenright@northandoverma.gov> 1665 Great Fond Road - Revised ManlResponse to Comment Lisa Eggleston <lisa@egglestonenvironmental.com> Mon, Feb 22, 2016 at 1:48 PM To: Dennis Griecei <dgriecci@andoverconsultants.com>, Jendght@norlhandoverma.gov Cc: Jennifer Hughes <Jhughes@townofnorthandover.com> Jean, have received and reviewed the February 10, 2016 response and revised plan from Andover Consultants for 1665 Great Pond Road, and it appears that most of my comments have been satisfactorily addressed. It should be confirmed that all of the roof runoff from the new house can be drained to the single proposed roof infiltration trench on the north side of the house. c ye !�u e ct#ct cl- ���ry _--su aces, I also recommend that the new/overlay portion of the driveway be graded to drain onto pervious areas of the lot, and not directly down toward Great Pond Road and the lake. Please let me know if you have any questions or need anything else. Lisa D. Eggleston, P.E. Eggleston Environmental 32 Old Framingham Rd, Unit#29 Sudbury, MA 01776 Tel 508.259.117 From: Dennis Griecci<dgriecci@andoverconsultants.com> Date:Thursday, February 11,2016 at 5:17 PM To:<Jenright@northandoverma.gov> Cc: Lisa Eggleston<lisa@egglestonenvironmental.com> Subject: 1665 Great Pond Road-Revised Plan/Response to Comment [Quoted text hidden] 4, hops:/I pail.google.com/ma:,Uul0r>ui=2&ik=7c2eff6265&view=pt&search=inbox&msg--153Oa4fca7bod9fc&siml=1530a4fca7bod9rc ttt Eggleston Environmental .?", January 5, 2016 North Andover Planning Board 1600 Osgood Street North Andover, MA 01845 Attn: Jean Enright, Assistant Director of Community Development RE: Watershed Special Permit 1665 Great Pond Road, Technical Training Foundation Trust-Petitioners Dear Ms. Enright and Board Members: Per your request, 1 have reviewed the December 1, 2016 Watershed Special Permit Application packet for the above-referenced project. Included in the materials I received and reviewed were the following: • Special Permit Watershed Permit Application, 1665 Great Pond Road, Tccbnical 'Fraining Foundation Trust, Petitioners. • Memorandum in Support of Application for Watershed Protection District Special Permit from Sniolak & Vaughan, LLP, 1665 Great Pond Rd, Technical Training Foundation Trust, Applicant. ® Watershed Special Permit Project Description & Written Documentation, 1665 Great Pond Rd, prepared for Technical Training Foundation Trust by Andover Consultants, Inc. and dated December 1,2015. ® Watershed Special Permit Site Plan, 1665 Great Pond Rd, prepared for Technical Training Foundation Trust by Andover Consultants, Inc. and dated December 1, 2015. 1 also conducted a brief site visit on December 15, 2015 to observe existing drainage patterns. My primary focus in this technical review is on the overall storn-1water 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 project site is a 29,665 sf lot on the north side of Great Pond Road. It is currently developed with a single-family home, driveway, retaining walls and lawn areas. Existing drainage on the site is overland toward Lake Cochichewick. The proposed project calls for razing of the existing home on the site and construction of a new single family home with approximately the same footprint. According to the Project Description, the proposed plan would represent a net decrease in impervious area of about 1,262 sf. Nearly all of the proposed work area is within the Non-Disturbance Zone of the Watershed Protection District, except for a small area at the back of the lot that is within the Non-Discharge Zone. The lot was created prior to October 24, 1994, therefore the 32 Old Framingharn Rd Unit 29 Sudbury MA 01776 tel 508.259.1137 i 1665 Grcat fond Rcl 2015 WSP application 2 January 5, 2016 Conservation Zone restrictions of the Watershed Protection District do not apply. No work is proposed within the 100-ft wetland buffer. My comments on the application are outlined below: 1. The Watershed Protection Zones shown on the plan appear to be based only on setbacks from Lake Cochichewick. Rea's Pond to the east of the property is a tributary wetland within the Watershed Protection District and may also have protection zones that extend onto the property. 2. The proposed project is an allowable use under Section 4.136 (3)(c) of the Zoning Bylaw. However, since the proposed new house would not be in the same footprint as the existing structure, it is unclear whether it would be considered replacement of an existing permanent structure or construction of a new permanent structure under the Bylaw. Construction of a new permanent structure requires a variance from the Board of Appeals. 3. It should be clarified whether the "edge of water" shown on the plan represents the annual mean high water mark of Lake Cochichewick as is required under Section 4.136(4)(c) of the Bylaw. Likewise, the edge of all wetland resource areas within 400 feet of the property (including Rea's Pond) needs to be confirmed by the Conservation Commission. 4. The alternatives analysis should address why the proposed new structure needs to be located approximately 12 feet closer to the lake than the existing house. 5. Section 4.136(3)(c) of the Bylaw calls for all construction in the Watershed Protection District to comply with Best Management Practices (BMPs) for erosion, siltation, and stormwater control to protect the lake and groundwater resources. Section 4.136(4)(g) requires that, within the Non-Disturbance and Non- Discharge Zones any runoff from impervious surfaces be recharged onsite or, where recharge is infeasible, other BMPs be employed. As shown on the plan, however, the proposed project does not provide any groundwater recharge or stormwater BMPs other than temporary erosion controls. Particularly since an entirely new structure is proposed, it should be feasible to direct the roof runoff into drip trenches or drywells,with any overflows directed onto pervious surfaces. It may also be possible to grade the reconstructed portion of the driveway to drain toward a bioretention area or infiltration trench, or at least onto pervious areas, rather than directly downslope toward the lake as it currently does. 6. I note that a portion of the existing driveway and a retaining wall are located on the abutting property to the west of the project site, and there is a lawn area that appears to be associated with the existing home that extends onto the abutting property to the east. It should be confirmed that no work is proposed on either of these abutting properties. i 1665 Great fond Rci 2015 WSW application 3 January 5, 2016 7. The plan should clearly indicate all structures and impervious surfaces to be removed from the site and should identify all proposed surfaces (including vegetation) within the limit of work. 8. As with similar projects in the Watershed Protection District, the creation of new lawn area be limited to that which is absolutely necessary, and any new landscaping should be 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 G-inches of topsoil and, where possible, native vegetation should be planted to minimize the need for fertilizer and watering. The use of fertilizers and other landscape chemicals on the site should be limited to organic, slow-release and low-phosphorus products. Also consistent with recently permitted projects within the District, both the limits of approved clearing and the restriction on lawn care products should be permanently recorded on the deed to the property. 9. 1 also recommend that the use of coal tar-based pavement sealants be prohibited on the property, as they have been determined to contribute high levels of polycyclic aromatic hydrocarbons (PAHs) to storrnwater runoff. 10. It should be confirmed that the proposed house design does not call for any copper-or other architectural metal. Runoff from metal roofs (or roofing elements) cannot be infiltrated in a Zone A and should be prohibited within the Watershed Protection District to prevent the leaching of toxic heavy metals into the water supply. 11. The proposed project will entail less than an acre of land disturbance and will not require coverage under the EPA Construction General Permit. The Planning Board may therefore want to require that the applicant or site contractor submit an erosion control plan prior to any site disturbance. At a minimum, a construction schedule aimed at minimizing the total area and duration of soil disturbance/stockpiling should be provided. Given the slope and proximity to the lake, I also suggest that silt fence be used in addition to the proposed staked hay bales (or with straw wattles) to prevent erosion and sedimentation. 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, EGGLEMN ENVIRONMENTAL �s Lisa D. Eggleston, P.E.