More Than Half of Massachusetts’ Waterbodies Are ‘Impaired’

New Bedford and Fall River are among nearly two dozen Massachusetts communities with combined sewer overflow (CSO) systems.

Very costly federally mandated construction projects are underway to update the sewer systems in both communities.

The Massachusetts Rivers Alliance (MRA) says, "These combined systems collect both sewage and rainwater into one pipe. Under normal conditions, these pipes transport all of the collected wastewater to a sewage treatment plant, then discharge the treated water to a waterbody."

Get our free mobile app

The New Bedford Wastewater Treatment Plant is on South Rodney French Boulevard.

"During heavy rain, the amount of water entering the pipes exceeds their capacity, so, by design, the pipes discharge some of the untreated mixture into a waterbody," according to the Alliance.

Heavy rain can result in high bacterial counts in the water, forcing the City of New Bedford to limit access to the municipal beaches.

The Massachusetts Department of Environmental Protection (MassDEP) says there are 19 communities with as many as 194 CSOs in Massachusetts. As of October 2023, New Bedford had 26 and Fall River had 17.

"Communities with CSOs include most of the older urbanized communities across the state, such as Boston, New Bedford, Worcester and Springfield," according to MassDEP.

All CSO communities must "implement system controls," known as the "Nine Minimum Controls." MassDEP says, "The purpose of these controls is to maximize the efficiency of existing facilities in order to limit the duration and impact of CSO discharges."

According to the Massachusetts Rivers Alliance, "Stormwater runoff is recognized by the EPA as the #1 source of water pollution in Massachusetts and the primary reason why more than half of our waterbodies are considered 'impaired.'"