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Boston Harbor and Massachusetts Bay
Massachusetts Water Resources Authority

What's New
Archive

What's New
in Environmental Quality


MWRA must report on the quality of the treated wastewater, or effluent, being discharged to Massachusetts Bay from the Deer Island Treatment Plant. Our discharge permit also requires us to monitor the ecosystem of Massachusetts Bay and Boston Harbor, measuring the health of fish and shellfish, as well as nutrients, pathogens, metals, and toxicity.

MASSACHUSETTS BAY WATER QUALITY

Proposed final modifications to the permit-attached Ambient Monitoring Plan

Outfall Monitoring Overview

Massachusetts Bay page

Bacteria Monitoring near the bay outfall

Ambient monitoring quarterly (PDF)

Contingency Plan thresholds compared with ambient data (PDF)


BOSTON HARBOR
& BEACH MONITORING

Boston Harbor

Sampling data

Boston Harbor beaches and beach fact sheets

Fish & shellfish in Boston Harbor & Mass. Bay

Winter flounder in the Harbor and Bay

WASTEWATER TREATMENT MEASURES

Contingency Plan threshold exceedance: effluent nitrogen (1/16/2020) (PDF)

Discharge Monitoring Reports for Treatment Plant and CSO facilities (PDF)

Contingency Plan thresholds compared with effluent monitoring data (PDF)

Infiltration and Inflow report (PDF)

Demand Management, Flow Limitation (PDF)

Deer Island Treatment Plant monthly performance (PDF)

Treatment Plant annual maintenance (PDF)

TRIBUTARY RIVERS
& SEWER OVERFLOWS

MWRA samples Boston Harbor's tributary rivers to measure the impacts of combined sewer overflows (CSOs) and analyze monitoring data. Learn more about the Charles, Mystic, and Neponset rivers.

Combined & Sanitary Sewer Overflows

CSO sampling location map

CSO receiving water quality report, 2019 (PDF)