Notification of Sewage Discharges

State regulations require BWSC to notify the public when certain events occur that result in untreated or partially treated wastewater being released into surface water--a river or stream, lake, or ocean. Notifications are posted online and also sent out via email and text. All Data are preliminary and subject to change. Subscribe to BWSC CSO notifications.

BWSC Public Notification Plan

BWSC is submitting to the Massachusetts Department of Environmental Protection (MassDEP) a CSO Public Notification Plan describing how it will comply with the requirements of An Act Promoting Awareness of Sewage in Public Waters, signed into law in 2021. Written comments can be submitted until February 24, 2023 to (email preferred) or by mail to 100 Cambridge St, Suite 900 Boston, MA 02114. Comments can also be emailed to BWSC at


The map below shows the locations of the Commission's active CSO outfalls and the status of their discharges. Discharges from CSO outfalls consist, or likely consist, of untreated or partially treated sewage and waste. The public is advised to avoid contact with impacted water bodies for 48 hours after the discharge or overflow ceases due to increased health risks from bacteria and other pollutants.

For more information regarding receiving water quality and bathing beach closures and advisories see the following websites.



Moving Around the Map

  • Click the plus/minus buttons on the right side to zoom in/out of the map
  • Hold down the left mouse button and drag to pan the map