Advocates of Rockland, Abington, Weymouth & Hingham (ARAWH) Draft Report: Weymouth Water Supply & Regulatory Review Technical Assistance Services for Communities 2010 Thursday, November 4, 7:00 8:45 p.m.
Background Former South Weymouth Naval Air Station (Site) LNR / South Shore Tri-Town Development Corp. in early stages of site redevelopment. SouthField: 2,855 residential units 2 million square feet of commercial space Commuter rail station Golf course, trails, protected wetlands and open space ARAWH raised concerns about environmental and fiscal impacts of the Site s redevelopment. 2
Overview ARAWH concerns Weymouth Water Supply System Safe Yield and Firm Yield Herring Run Future Water Supply Waste Water 3
ARAWH Concerns Water Supply Existing interim water supply agreement for Phase 1 of SouthField (245,000 gallons per day or gpd) Potential water supply agreements for full build-out of SouthField (1.4 million gallons per day or mgd) Fluctuations ti in Whitman s Pond water levels. l Drawdown of Whitman s Pond and impacts on Herring Run 4
ARAWH Concerns (continued) Waste Water Interim wastewater service agreement with Weymouth for Phase 1 of SouthField (187,000 gpd). Proposed on-site wastewater treatment facility and downstream impacts. 5
Whitman s Pond South Cove October 2007 May 2010 Photographs were taken by Mary Parsons. 6
Whitman s Pond - North Side May 2010 August 2010 Photographs were taken by Mary Parsons. 7
Weymouth Water Supply Current Regulations Massachusetts Water Management Act (WMA) registered and permitted withdrawals. Registered Volume (90%): 4.51 mgd from seven sources. Permitted Volume (10%): 0.49 mgd from one source. Allowable Withdrawal: 5.0 mgd. 8
Regulated Sources and Withdrawal Volumes for Town of Weymouth Withdrawal Type Source Average Volume per Day Registered Sources Great Pond 4.51 mgd Old Swamp River/South Cove Whitman s Pond Circuit Avenue Well Main Street Well Libbey Park Winter Street Well #2 Permitted Sources Winter Street Well #1 0.49 mgd 9
Safe Yield An estimate of the maximum amount of water available from a source, given historic drought trends and potential environmental impacts of water withdrawals. MassDEP uses Safe Yield to assess basin-wide water supply capacity. For Weymouth, additional water needed above current allocations would require a permit and consideration of Safe Yield limits. 10
Firm Yield An estimate of the maximum amount of water available from a reservoir, calculated based on historic drought conditions; may not consider environmental impacts of withdrawals. MassDEP uses Firm Yield as the basis for permitting maximum annual withdrawals from a reservoir. 11
Safe Yield Study and Approvals Estimates Firm Yield of Great Pond System - 3.63 mgd Documents the approved Safe Yield of ground water sources - 2.64 mgd. Approved yield of Weymouth s ground and surface water sources - 6.27 mgd. 12
Weymouth Water Production (2000-2009)) Year Total Production Volume (mgd) Average Daily Production Volume (mgd) Annual Rainfall (inches) 2000* 1,639 4.49 N/A 2001* 1,612 4.41 N/A 2002 1,550 4.19 51.50 2003 1,520 4.15 56.84 2004 1,570 4.15 46.80 2005 1,489 4.27 68.00 2006 1,561 4.28 64.00 2007 1,461 4.00 46.31 2008 1,410 3.86 55.67 2009 1,411 3.87 55.59 10-year average 1,552 4.17 55.59 13
Current Usage / Available Capacity Weymouth s allowable withdrawal volume is 5.0 mgd. Estimated yield of Weymouth s surface water and ground water sources is 6.27 mgd. In 2009, the Town of Weymouth s average daily withdrawal volume was 3.87 mgd (77% of allowable withdrawal / 62 % of the estimated yield). From 2000-2009, the Town s average daily withdrawal volume was 4.17 mgd (83% of allowable withdrawal volume / 66 % of the estimated yield). 14
Herring Run Connects Whitman s Pond (herring spawning habitat) with Back River and Atlantic Ocean. Relies on adequate Herring Run at Jackson Square in Weymouth (photograph taken by Mary streamflow and Parsons) releases from Whitman s Pond. 15
Herring Run Regulations Streamflow requirements for Herring Run established in permit conditions for Winter Street Well #1. Streamflow requirements considered in Firm Yield Approval. No current regulations prevent drawdown of Whitman s Pond from surface water withdrawal. 16
Capacity and Future Water Supply Town has agreed to supply 245,000 gpd to SSTTDC to support Phase 1 at SouthField. Weymouth is registered and permitted to withdraw 5.0 mgd and used an average of approximately 4.17 mgd over the past 10 years. There is additional capacity of 0.83 mgd, sufficient to support Phase 1 and current water supply agreement. If Town of Weymouth supplies the full 1.4 mgd projected y g j water usage for SouthField, a permit to withdraw an additional.57 mgd would likely be required. 17
Waste Water Town of Weymouth has agreed to accept up to 187,000 gpd in sewer flows from SSTTDC to support Phase 1 at SouthField. Infrastructure upgrades in Weymouth would be needed to accept waste water flows of 1.47 mgd projected for full build-out. SSTTDC has initiated the permitting process for a proposed on-site water reclamation facility that would be permitted for ground water discharge up to 1.9 mgd. 18