Part 2, Sec. 2C9
Human Activities - Ocean Discharges

9. Ocean Discharges

Massachusetts Bay and Cape Cod Bay receive waste, in the form of effluent or sludge, from a number of pipes extending from municipal wastewater treatment plants (Figure 14) (MBP Management Committee, 1989). The total combined flow of this material is reported to be 566 million gallons per day (MGD), with approximately 500 MGD of that total discharged by the existing Massachusetts Water Resources Authority (MWRA) treatment works at Deer and Nut Islands, the plants that serve the greater Boston Area. Most industrial discharges enter Massachusetts Bay through the municipal wastewater treatment plants, principally the MWRA system.

The MWRA is currently involved in the construction, to be completed by 1999, of a new wastewater treatment facility on Deer Island. The new plant will provide more effective, secondary treatment of the wastewater, and eliminate the discharge of sludge into coastal waters (by 1991). The discharge point, an ocean outfall, is to be relocated from the entrance to Boston Harbor to an area between 7.9 and 9.4 statute miles (or 12.7 and 15.1 km) east-northeast of Deer Island (Figure 15). This location is approximately 12.5 nautical miles (23.12 km) from the Sanctuary study area.

An extensive environmental assessment of the potential environmental effects of the proposed outfall was undertaken by the MWRA, with the results published in Volume V, "Effluent Outfall", of the MWRA Secondary Treatment Facilities Plan (1988), and appendices. An Environmental Impact Statement (EIS) was also prepared by the EPA for this project. Each of these documents concluded that a diffuser-type outfall located in the area identified above would be environmentally acceptable.

Increases in discharge volume have also been proposed for the South Essex Sewer District and the Town of Plymouth, discharging into Massachusetts Bay and Cape Cod Bay, respectively. No points source discharges have been proposed directly within the Sanctuary.

The Massachusetts Ocean Sanctuaries Act prohibits any new discharge of wastewater into areas designated as ocean sanctuaries. (Such areas encompass all of the Massachusetts coast except for the area between Marshfield and Lynn). A recent amendment to the Ocean Sanctuaries Act adds a variance procedure to allow increases in discharge volumes from existing wastewater treatment plants if a strict set of criteria are successfully met.

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