HomeMy WebLinkAbout230502_Rev_1st_SWPeerReview_185GreatPondRoad - - 185 GREAT POND ROAD Horsley Witten GroupSustainable Environmental Solutions
112 Wafer Street•80"Floor•Boston,AAA 02109 „
857-263-8193•horsleywit¢en.com
May 2, 2023
Ms. Jean Enright, Planning Director
Planning Department
Town of North Andover
120 Main Street
North Andover, Massachusetts 01845
Re: Initial Stormwater Peer Review
Proposed Swimming Pool — 185 Great Pond Road
North Andover, Massachusetts
Dear Ms. Enright and Board Members:
The Horsley Witten Group, Inc. (HW) is pleased to provide the North Andover Planning Board
with this letter report summarizing our initial review of the Watershed Special Permit Application
and Plan of Land for the proposed swimming pool project at 185 Great Pond Road in North
Andover, MA. The plans were prepared by Williams & Sparages on behalf of Tammy Woolfolk
and Hans H. Kim (Applicant). The project proposes the installation of a 14 foot by 30 foot in-
ground swimming pool, with a paver patio, and a fence. The stormwater management for the
proposed improvements includes a 12-inch wide, 2-foot-deep infiltration trench surrounding the
patio to allow stormwater from the patio to infiltrate into the ground during a storm event. In
addition, the swimming pool will be equipped with a non-backwash filtration system. The
proposed pool is a 420 square foot (sf) permanent structure. The footprint of the existing house
is approximately 3,200 sf. A total of approximately 1,500 sf of additional impervious area
including the pool and paver patio is proposed within the 4.20-acre parcel.
The residential lot was created prior to October 24, 1994 and is located within the Watershed
Protection District. The project is proposed within the Non-Discharge Zone from the edge of a
wetland resource area located to the rear of the existing house. The closest point of the
proposed patio surrounding the pool is approximately 113 feet from the resource area to the
south. The proposed limit of disturbance is greater than 100 feet from the wetland resource
area. The entire project is located outside of the 100-foot Non-Disturbance Zone. In accordance
with §195-4.19 B. (2) of the North Andover Zoning Bylaws, any surface or subsurface discharge
of stormwater within the Non-Discharge Buffer Zone is only allowed after a special permit has
been granted by the North Andover Planning Board.
The following documents and plans were received by HW:
• Watershed Special Permit Application, 185 Great Pond Road, North Andover,
Massachusetts, prepared by Williams & Sparages, dated April 14, 2023 (13 pages); and
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Town of North Andover
May 2, 2023
Page 2 of 3
• Plan of Land for 185 Great Pond Road, North Andover, Massachusetts, prepared by
Williams & Sparages, dated April 14, 2023 (1 sheet).
Stormwater Management Design Peer Review
In accordance with §195-4.19. B. (4)All construction in the Watershed Protection District shall
comply with best management practices for erosion, siltation, and stormwater control in order to
preserve the purity of the groundwater and the lake; to maintain the groundwater table; and to
maintain the filtration and purification functions of the land.
HW has the following comments regarding the proposed stormwater management design.
1. The Applicant is subject to the requirements of§195-4.19 B., "Non-Discharge Buffer
Zone." §195-4.19 B (2) reads: Uses allowed by special permit. The following activities
may be allowed within the Non- Discharge Buffer Zone only by the granting of a special
permit issued pursuant of§ 195-4.20 of this Watershed Protection District Bylaw:
(a) Any surface or subsurface discharge, including, but not limited to, stormwater runoff;
drainage or any roadway that is maintained by the Division of Public Works or any
private association; outlets of all drainage swales; outlets of all detention ponds. All
stormwater management systems shall employ best management practices.
The Applicant has provided a stormwater management system that employs best
management practices. No further action required.
2. The Applicant has included erosion controls on the Plan and has shown where the
stockpiles will be located during construction. HW recommends that the Applicant
include an additional mulch sock or silt fence surrounding the stockpiling area for erosion
protection.
3. The Applicant has proposed a construction access to the back yard around the south
side of the house. HW recommends that the Applicant include construction matting to
limit the tracking of sediment offsite or onto the driveway.
4. The Applicant proposes that the swimming pool be equipped with a non-backwash
filtration system. HW recommends that the Applicant include information and a checklist
log about inspecting the filtration system in the Operations and Maintenance Plan.
5. The Applicant has noted in the O&M Plan that when during normal dewatering following
storm events, the pool water shall be pumped into the infiltration trench. HW notes that
the pool water should be dechlorinated prior to being pumped to the infiltration system.
6. HW agrees that the infiltration trench surrounding the patio will provide adequate
stormwater management for the additional impervious surface. No action required.
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May 2, 2023
Page 3 of 3
Conclusions
HW recommends that the North Andover Planning Board require the Applicant to address these
recommendations as part of its review process. We appreciate the opportunity to assist the
Town of North Andover with this project review. Please contact Janet Bernardo at 508-833-6600
or at if you have any questions regarding these comments.
Sincerely,
HORSLEY WITTEN GROUP, INC.
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Janet Carter Bernardo, P.E. Steve Stanish, P.E.
Associate Principal Senior Engineer
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