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Boston Harbor and Massachusetts Bay
Massachusetts Water Resources Authority


Monitoring Bacteria in the Bay

MWRA monitors bacteria at locations surrounding the MWRA outfall and elsewhere in Massachusetts Bay (see station map below). Water samples are analyzed for sewage indicator bacteria: fecal coliform and Enterococcus. Enterococcus is now recognized by the U.S. Environmental Protection Agency as a better indicator of public health risk to saltwater swimmers. Fecal coliform is used by the Massachusetts Division of Marine Fisheries to monitor water quality in shellfish areas.

Massachusetts Bay Bacteria Monitoring Stations