AGAWAM, Mass. (WWLP) – We now have more information on how major rain events are affecting sewage runoff into Massachusetts waterways. In 2020, some one million gallons of unfiltered discharge reached public waterways. This discharge is a combination of rainwater and sewage, and is released into waterways when the storm sewer system is overwhelmed with water.

Most of that discharge is filtered before it hits waterways, but not all of it. If the system is overwhelmed, like when we have heavy rainstorms, discharge can be a problem. The water flows into rivers and streams, so that it doesn’t back up into your home.

From January through August of this year, sewage overflows in the Massachusetts Water Resources Authority service zone discharged more than twice the rainwater/sewage combination into public waterways than in all of 2020. Through just last month, there had been 80 times the system had been overwhelmed; totaling 594 million gallons of the potentially-unfiltered mix released into waterways, according to the Executive Office of Energy and Environmental Affairs.

Last week’s heavy rain adding to an already wet summer prompted a closer review of discharge data across the state.