Conservation Commission
Meeting
June 3, 2010
Peg Arguimbau Chairman, Hank Langstroth, Elizabeth McGrath, Meredith deCarbonnel, and
Stephen Cremer were the members present.
Peg recused herself from the following hearing due to a potential conflict of interest relating to her association with the Sharon School System.
Hank Langstroth, Acting Chairman, officiated the meeting at this point
7:45 p.m., N.O.I. Hearing continuance filed by the Town of Sharon School Department for the proposed additions and renovations to the existing Sharon Middle School, DEP File # SE-280-0512:
David McKinley, Landscape Architect, from Kaestle Boos Associates, Inc., and Christopher Garcia, P.E., from Garcia, Galuska & DeSousa, Inc., appeared before the Commission.
David McKinley explained to the Commission that the preliminary version of the SWPPP
(Stormwater Pollution Prevention Plan) has been submitted to Peter O’Cain and is awaiting his approval. The Peer Review Report has been completed by PSC (Professional Services Corporation)
as requested by the Commission.
Christopher Garcia explained to the Commission that the design calculations for the stormwater discharge system related to the proposed project have been revised to meet the ZBA’s requirement concerning the 1- year storm event. Garcia, Galuska, and DeSousa submitted a letter to the Commission dated 6/3/10 in response to the concerns outlined in PSC’s stormwater management review report. Christopher Garcia reviewed the following information with the Commission:
- The proposed revised drainage system design for the project includes modifications made to the outlet control device within subsurface detention #2 and the installation of additional
bio-retentions within the parking lot island areas of the site. These improvements are being
proposed to increase the groundwater recharge and meet the 1- year storm event requirement. The calculations for the 1-year stormwater runoff volume from the proposed project have been revised to 0.607 acre-feet leaving the site as opposed to 0.609 acre-feet.
- Sketches SKL - 3 and SKL - 4 have been re-designed concerning soil and vegetated strip requirements for the two proposed bio-retention areas.
- The calculations for modeling the stormwater runoff for the infiltration system within the N2 area on the proposed drainage conditions plan has been re-designed to control the 10, 25, and 100- year storm events.
- The review from PSC indicated that, typically, culverts are required to be designed for a
25-year storm event. The consultants from PSC agreed with Garcia, Galuska, and DeSousa’s explanation that the proposed closed pipe conveyance calculations were designed to control a 100-year storm event to ensure that stormwater runoff would discharge into the subsurface detention basins.
- The consultants from PSC also agreed with Garcia, Galuska, and DeSousa’s proposal that the times-of-concentration for the piping network be designed for a 100-year storm event as opposed to a 25-year storm event.
David McKinley explained to the members of the Commission that the NPDES has been submitted
to the EPA and will provide the Commission with a copy of the permit when available.
Hank called for a motion for the Commission to close the hearing and to issue an Order of
Conditions
to the Applicant contingent upon receipt of the SWPPP approved by the Town Engineer, Peter
O’Cain.
Elizabeth McGrath moved. Stephen Cremer seconded. Voted. 4-0-1.
Elizabeth McGrath moved and Meredith deCarbonnel seconded to amend the motion to include the Commission’s receipt of the final approved revised plan dated 6/3/10. Voted. 4-0-1.
Page 2 SCC 6/3/10 Meeting Minutes
Peg returned to the meeting at this point and officiated the meeting
8:15 p.m., Signatures:
The Commission signed bills. Order of Conditions for the Sharon Middle School, 75 Mountain St.,
DEP File # SE-280-0512. Certificate of Compliance for 69 Edge Hill Rd., DEP File # SE-280-0495.
Hank Langstroth left the meeting at this time.
8:20 p.m., Approve Past Meeting Minutes:
Peg called for a motion to approve the April 15, 2010 Meeting Minutes as presented.
Elizabeth McGrath moved. Meredith deCarbonnel seconded. Voted. 3-0-1.
Peg called for a motion to approve the May 6, 2010 Meeting Minutes as presented.
Stephen Cremer moved. Elizabeth McGrath seconded. Voted. 3-0-1.
Peg called for a motion to approve the May 20, 2010 Meeting Minutes as amended.
Meredith deCarbonnel moved. Stephen Cremer seconded. Voted. 3-0-1.
8:40 p.m., Adjournment:
Peg called for a motion to adjourn.
Meredith deCarbonnel moved. Elizabeth McGrath seconded. Voted. Unanimous. 4-0-0.
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