Long Term Bacteria Monitoring in Boston Harbor

Kelly Coughlin
Environmental Quality Department
Massachusetts Water Resources Authority
Delivered at 2003 Boston Harbor Islands Science Symposium.

The Massachusetts Water Resources Authority’s (MWRA) $4 billion Boston Harbor Project to remediate sewage discharges in Boston Harbor was completed in 2001. MWRA has been monitoring the effects of the project on harbor water quality since 1989. A major concern was the effect of pathogens in wastewater and sludge discharged to the harbor on public health. MWRA monitored two types of indicator bacteria, fecal coliform and Enterococcus, to track the effects on water quality as different stages of the project were completed. The data show improvements in bacterial water quality throughout the harbor as pumping capacity improved, sludge discharges ended, secondary treatment came on-line and the harbor outfalls were decommissioned. Now, most of Boston Harbor meets the most stringent marine bacterial water quality criteria recommended by EPA.

Problem areas still exist at the mouths of rivers tributary to the harbor and along the shoreline. Urban runoff during storms, combined sewer overflows (CSOs) and illicit sewer connections still contribute to contamination along the shoreline. MWRA will continue to monitor harbor bacterial water quality as its projects to remediate CSOs are implemented and as local communities address storm water contamination problems.

Last updated: February 26, 2015

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