Boston Harbor South Watersheds 2004 Assessment Report

This report includes assessments covering the four individual watersheds that discharge into Boston Harbor from south of the City of Boston — the Neponset, Weir, Fore and Back River Watersheds — plus an assessment for those portions of the City of Boston which border the Harbor itself south of the Charles River, hereinafter referred to as “Boston Inner Harbor Watershed.” The companion to this report is the “Boston Harbor South Watersheds 2004-2009 Action Plan,” which spells out a comprehensive set of responses needed to remedy problems identified here. This document does not cover the two major watersheds that discharge to the Harbor to the north of Boston — the Charles and Mystic River Watersheds - nor those sections of Boston that border or discharge into these watersheds. Therefore, it is not the purpose of the Assessment to analyze the health of the Boston Harbor itself, but rather to look at the environmental health of the individual watersheds from their headwaters to their discharge points into the Harbor, plus direct discharges into the Harbor from Boston. Since MWRA began pumping sewage from Deer Island to its outfall pipe in Massachusetts Bay, most of the pollution in the Harbor itself comes from the contributions of the various rivers discharging into the Harbor and Combined Sewage Overflows (CSOs) from the City of Boston. MWRA data indicate that it is the Charles and Mystic Rivers, and not the rivers covered in this report, which are the largest contributors to the Harbor’s pollution. In any case, extensive research by MWRA has been unable to pinpoint the exact pollutant contributions coming from each individual watershed. This report is based on a review of existing data and studies relevant to each of the watersheds, including water quality data reports, shoreline survey reports, EOEA’s Basin-wide Water Quality Strategy, relevant municipal plans, DEP reports, regional buildout analyses, Massachusetts Geographic Information Systems (MassGIS) data, and other relevant materials from non-governmental, academic, local, regional, state and federal sources

An Application for a State Designated, Federally Approved No Discharge Area for Boston Harbor, MA

The municipalities surrounding Boston Harbor are requesting that the Commonwealth of Massachusetts designate the waters of Boston Harbor as a No Discharge Area (NDA) pursuant to the Clean Water Act, Section 312(f)(3). An NDA is a body of water in which the discharge of vessel sewage, whether treated or not, is prohibited. The No Discharge Area would be called the Boston Harbor No Discharge Area. While the waters of Boston Harbor are under the jurisdiction of a number of different municipalities, water quality issues affect the harbor as a whole. Past efforts to clean up the harbor have occurred across municipal boundaries and efforts to reduce vessel sewage inputs to the harbor should be addressed in a similar fashion. The fact that boating activity in the harbor also crosses municipal boundaries suggests that a harbor-wide approach is the most appropriate. Vessel sewage, like many other pollutants, can be harmful to the environment when it is not adequately treated. Sewage contains high concentrations of nitrogen, a substance that can lead to algal blooms and low dissolved oxygen concentrations, which in turn can affect the health of fish, shellfish, and eelgrass beds. Sewage also contains bacteria and viruses that can make shellfish unsuitable for human consumption, can be a risk to human health and can severely restrict recreational opportunities (e.g. when swimming is prohibited at beaches due to elevated fecal coliform levels)