Public Health Warning Issued Related To Recent Sewage Discharge

 BOSTON – October 15, 2025 –  The following is a public health warning related to recent sewage discharge, also known as a combined sewer overflow (CSO). State regulations require local public health departments to provide notice to the public when these discharges may create a risk to public health, including when a discharge lasts for more than two hours.    

A combined sewer overflow occurs when a large storm overwhelms the combined sewerage system causing rainwater to mix with wastewater and discharge to a nearby water body. This prevents sewage backups into homes and businesses.  The public is advised to avoid contact with affected water bodies for at least 48 hours after a sewage discharge or overflow, during rainstorms, and for 48 hours after rainstorms end, due to increased health risks from bacteria or other pollutants associated with urban stormwater runoff and discharges of untreated or partially treated wastewater.    

• Boston Water and Sewer Commission outfall BOS070 in the Fort Point Channel experienced a discharge or overflow that started on  October 13 at 1:05 p.m. and ended on October 13 at 5:20 p.m., creating a potential public health risk. This event impacts the waters of Fort Point Channel and the Downtown and South Boston waterfront. This advisory will expire at 5:20 p.m. on Wednesday, October 15, 48 hours after the overflow ended. 
• Massachusetts Water Resources Authority outfall MWR203 at the Prison Point facility experienced a treated discharge or overflow that started at 3:07 p.m. on October 13 and ended at 6:43 p.m. on October 13. This event impacts the inner harbor. This advisory will expire at 6:43 p.m. on Wednesday, October 15, 48 hours after the overflow ended. 
• Boston Water and Sewer Commission outfall BOS010 near Central Square in East Boston experienced a discharge or overflow that started on  October 14 at 6:05 p.m. and ended on October 14 at 8:30 p.m., creating a potential public health risk. This event impacts the waters of the Upper Inner Harbor. This advisory will expire at 8:30 p.m. on Thursday, October 16, 48 hours after the overflow ended. 

For more information about CSOs and to sign up for CSO notifications for Boston Harbor and Fort Point Channel, please visit the Boston Water and Sewer Commission’s CSO notification page.  

For notifications and alerts for sites on or around the Charles River, please visit the MWRA’s CSO notification page.