MAINE PUBLIC • July 1, 2024
Maine's combined sewer systems released 745 million gallons of untreated sewage and storm water into the waterways last year. It's an increase of 244% compared to 2022 according to the Maine Department of Environmental Protection report. Many sewer systems in Maine use the same pipes to transport raw sewage and runoff collected from storm drains to water treatment facilities. Heavy rain events like the rainstorms seen last year can fill these combined sewers systems to capacity with wastewater. To prevent sewage from overflowing into homes, the pipes discharge the untreated wastewater into nearby waterways. There are 31 communities in Maine that use combined sewer systems — including Portland, which accounted for more than half of the state’s total overflow. More modern sewer systems use separate pipes so that only stormwater gets released during storm-related overflows.