BOSTON — The Boston Public Health Commission warned people to avoid contact with Boston's Inner Harbor after a sewage overflow during a storm lasted more than two hours, the commission said in a public health warning.

A Massachusetts Water Resources Authority outfall at its Prison Point facility had a treated discharge or overflow from 8:20 p.m. Friday until 12:07 a.m. Saturday, creating a potential public health risk, according to the commission. The advisory for the Inner Harbor ran until 12:07 a.m. Monday, 48 hours after the overflow ended.

Combined sewer overflows happen when a large storm overwhelms a sewer system that carries both rainwater and wastewater, sending the mix into a nearby body of water instead of letting sewage back up into homes and businesses.

The commission said people should stay out of affected waters for at least 48 hours after an overflow, during rainstorms and for 48 hours after rain ends, citing increased health risks from bacteria and other pollutants in urban stormwater runoff and untreated or partially treated wastewater.

State regulations require local health departments to notify the public when such a discharge may pose a health risk, including when one lasts more than two hours. Other, shorter overflows that did not meet that threshold may also have occurred, the commission said.

Residents can sign up for overflow notifications for Boston Harbor and the Fort Point Channel through the Boston Water and Sewer Commission. The MWRA issues notifications for sites on and around the Charles River.

This brief was drafted by AI from a public agency or political press release and published by The New England Signal. Why we use AI for stories like this one.