The City of Manchester has reached a deal with the state of New Hampshire and federal agencies to reduce the amount of sewage it discharges into nearby rivers by 75 percent.
The settlement, announced Monday by the U.S. Environmental Protection Agency, calls for an estimated $231 million upgrade to the city’s wastewater treatment system over the next 20 years.
Manchester has spent over $50 million in the last decade to reduce discharge, but a review by the EPA found that the city was continuing to discharge wastewater into the Merrimack River, Piscataquog River, and other waterways in violation of federal and state guidelines.
The wastewater included industrial waste, raw sewage and concentrations of E. Coli bacteria far above water quality standards.
According to the EPA, the Merrimack River is the main source of drinking water for more than 500,000 people, including in the Nashua area, Lowell, and Lawrence.