2.0 Water Quality Impairments (Please refer to Map 1-2 for the water quality assessment issues of the area.)
2.1 Stormwater Impacts
MassDEP used bacterial data collected by Camp, Dresser & McKee in 1999 and by the Division of Marine Fisheries between 1986 and 1995 to develop the TMDL for Little Harbor. According to the TMDL, the DMF data identified violations of water quality standards for shellfish harvesting along the perimeter of the harbor and fecal coliform bacteria were consistently high around Gammons Road. The CDM wet-weather sampling event, on September 30, 1999, “shows clearly that fecal coliform is high in the stormwater entering Little Harbor and results in water quality violations.” In addition to stormwater, possible sources of fecal coliform bacteria were identified as failing or inadequate septic systems, small farming operations, domestic animals or wildlife (MassDEP 2002). All other uses were unassessed.
Cohasset Harbor: Water Quality Classification: Class SA Cohasset Harbor is listed on the draft 2006 Integrated List of Waters in Category 5. This segment is impaired due to pathogens and a TMDL is required. Land-use estimates for the 17.6 square mile subwatershed is 58% Forest, 37% Residential and 7% Wetlands. Non-point pollution is causing the closure of some shellfish beds due to elevated fecal coliform bacteria (DEP, 2006).
Cohasset Cove Cohasset Cove, a Category 5 on the draft 2006 Integrated Lists of Waters is impaired by pathogens and a TMDL is required. . The DMF Shellfish Status Report of July 2000 indicates shell fishing for this area is prohibited. Potential pollution sources identified by DMF in this closed safety zone area include the Cohasset WWTP discharge and the marinas. Additionally septic systems and stormwater runoff are also potential sources (DEP, 2006). CZM’s Coastal Non-Point Source Program has awarded Cohasset $47,000 to investigate storm water hot spots (including James Brook), conduct water quality monitoring, and design storm water BMPs to mitigate pollution in Cohasset Cove (Jason Burtner, CZM).
Bassings Beach (Cohasset Cove): Weekly testing for Enterococci bacteria during the swimming season was conducted at the Bassing Sailing Club semi-public beach along the southern shore of Cohasset Cove, Cohasset/Scituate. Only one posting in the 2002 and 2003 beach seasons was reported (in 2003) although apparently not related to elevated bacteria counts (MDPH 2003 and 2004). During the summer of 2005 Bassings Beach was posted for the majority of the summer. The Massachusetts Department of Public Health conducted weekly sampling at Cohasset Sailing Club and Sandy Cove during the summer of 2005. According to this data, the level of endroccoci in the water at the Sailing Club exceeded the single sample standard of 104cfu/100ml four times and the standard based on the geometric mean of five or more samples (35 cfu/100ml) was exceeded twice at Sandy Cove.
South Coastal Watershed Action Plan 9/12/2006 Watershed Action Alliance