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Boston Harbor and Massachusetts Bay
Massachusetts Water Resources Authority

Regulatory Reporting
Archive

Regulatory Reporting

Because the Massachusetts Water Resources Authority discharges effluent from the Deer Island Wastewater Treatment Plant into Mass. Bay, it has been granted a federal National Pollutant Discharge Elimination System (NPDES) discharge permit by its regulators, the U.S. Environmental Protection Agency (EPA) and the Massachusetts Department of Environmental Protection (DEP). To ensure the protection of the receiving waters in Massachusetts and Cape Cod Bays, the permit includes monitoring requirements, pollution prevention measures, and a Contingency Plan to ensure that unexpected problems are swiftly detected and resolved. MWRA is required to post many monitoring results online.

WHAT'S NEW AMBIENT MONITORING
MWRA posts recent treatment plant performance and environmental quality reports on the What's New page. Many of these are required by the NPDES discharge permit.
MWRA measures environmental conditions in the Bays such as nutrients, metals, and algae blooms. Monitoring results are compared with pre-discharge baseline data, to help assess any impact of the discharge.
BEST MANAGEMENT PRACTICES CONTINGENCY PLAN
MWRA implements a best management practices plan to minimize contamination in runoff from the Deer Island Treatment Plant, headworks stations, Combined Sewer Overflow treatment facilities, and sludge pelletizing plant.

The Contingency Plan in the NPDES permit sets out Caution and Warning level thresholds for monitoring results that mandate further studies to detect any potential harm to Mass. Bay from effluent discharges. MWRA reports exceedances of the thresholds. The annual Outfall Monitoring Overview compares effluent and field data results from the previous year with these thresholds.
COMBINED SEWER OVERFLOWS DISCHARGE MONITORING

Notifications of discharges of combined sewage in the Charles and Alewife Brook/Mystic Rivers;

Annual water quality report for those rivers posted on our report list
Current CSO variances (mass.gov).
Notification of Cottage Farm discharges only (required by previous variance until 2020).
Learn more about CSO
post-construction monitoring
.


MWRA monitors the effluent discharged into Massachusetts Bay by the Deer Island Treatment Plant for a wide range of pollutants, and reports the results monthly to state and federal regulators. All monitoring data is made available to the public.

Discharge monitoring reports include:

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

Report on assessing effluent contaminants. (PDF)
DEMAND MANAGEMENT GROUNDWATER REMEDIATION
MWRA is subject to an average dry day flow limitation of 436 million gallons per day. This annual report assesses the effectiveness of demand management programs and water conservation efforts done by communities in the service area, to keep flow within limits.
MWRA prohibits discharges into the MWRA system for groundwater remediation activities. Any proposed changes to this rule must be posted online. There are currently no proposed changes.

LOCAL LIMITS OPERATIONS & MAINTENANCE
MWRA regulates discharges from certain business or industrial sewer users and prescribes limits for both the quantity and quality of discharged substances. MWRA must develop and enforce these limits to prevent pollutants from causing problems with permit compliance or system operations.

MWRA routinely maintains the sewage treatment and sludge pelletizing plants and submits to regulators annual status reports and a report on infiltration/inflow reduction efforts. MWRA also must report when there is an operational incident or upset at an MWRA facility.
OUTFALL MONITORING SCIENCE ADVISORY PANEL

POLLUTION PREVENTION
(TOXIC REDUCTION & CONTROL)

The Outfall Monitoring Science Advisory Panel (OMSAP) advises the US Environmental Protection Agency (EPA) and DEP on scientific and technical matters related to MWRA's bay outfall and any potential impacts of the discharge on its receiving waters. Materials from OMSAP Meetings are available online.

• Pollution Prevention Plan: addresses the quality of wastewater before it enters MWRA's sewerage system.
Industrial Waste Report: documents efforts to implement the requirements of 40 CFR Part 403, General Pretreatment Regulations.
A Healthy Environment Starts at Home: a guide to hazardous household substances, and their water quality effects.

PRIOR NOTICE ARCHIVE
MWRA must provide at least a 30-day prior notice of any significant change in the volume or character of pollutants being introduced into the treatment plant that may cause the discharge to exceed water quality standards in the receiving water.
The Archive page provides access to past environmental quality reports.