Boston Harbor and Massachusetts Bay

MWRA Environmental Quality Department



Discharge (Effluent) Monitoring

MWRA monitors the effluent (treated sewage) that is discharged into Massachusetts Bay, to ensure that it meets the standards set out in the NPDES permit.

Effluent Monitoring Reports:

Monthly discharge monitoring results from Deer Island Treatment Plant  (PDF) and Combined Sewer Overflow treatment facilities (PDF) are summarized in these tables submitted to federal and state regulators.

Plant Performance Data (PDF)
Monthly data on the Deer Island Treatment Plant's effluent discharges. Measurements of fecal coliform bacteria, suspended solids, oxygen depleting materials, and chlorine residual are included.

Contingency Plan Quarterly Report on Effluent Monitoring
Summary of data on pH, fecal coliform, toxicity, oil and grease, and nitrogen in Deer Island Treatment Plant effluent (treated wastewater) that is discharged into Massachusetts Bay.

NPDES Compliance Summary Report
This report, while not a regulatory requirement, provides a useful documentation of influent and effluent quality trends over the course of a fiscal year for the MWRA's Deer Island Treatment Plant and Combined Sewer Overflow facilities.

Outfall Monitoring Overview 
This report includes discharge monitoring program results for the latest year's effluent data. Results are compared to Contingency Plan thresholds.

 

Many of our reports are in PDF format, which requires Adobe Acrobat Reader®, a free program available from Adobe Systems. To request a paper copy of any report, please contact the MWRA Environmental Quality Department at 617-788-4601, or e-mail us at web.enquad@mwra.state.ma.us.