Merrimack Station1

A lawsuit filed Monday in federal court by a pair of environmentalist groups against Eversource and Connecticut-based Granite Shore Power claims the coal-fired Merrimack Station power plant in Bow (above) is violating the Clean Water Act.

CONCORD — A lawsuit filed Monday by a pair of environmentalist groups against Eversource and Connecticut-based Granite Shore Power claims violations of the Clean Water Act by the coal-fired Merrimack Station power plant in Bow.

Conservation Law Foundation (CLF) and the Sierra Club announced Monday that both groups filed a lawsuit in U.S. District Court in Concord.

“For decades, the plant has polluted the Merrimack River with heated wastewater that has changed natural fish population and is fueling the growth of invasive species,” states a joint release issued Monday by both groups.

The Bow plant was owned by Eversource until 2018, when it was sold to Granite Shore Power. Both utilities are named as defendants in the lawsuit.

Representatives from both environmental groups say the plant draws about 287 million gallons of water per day from the Merrimack River and heats up that water as a result of its cooling process before finally discharging the water back into the river, often at temperatures exceeding 90 degrees Fahrenheit.

The federal Clean Water Act defines heat as a pollutant and water discharges are required to take the protection of indigenous wildlife into account.

“Merrimack Station has seriously undermined the health of the Merrimack River for decades,” said Tom Irwin, Vice President and Director of CLF New Hampshire. “This dirty coal plant is damaging our climate and endangering public health, all while polluting an iconic natural resource. The owners of this plant must immediately address these offenses and ensure the Merrimack River is protected from further harm.”

“The Merrimack River is a major source of drinking water and recreation for our state,” said Catherine Corkery, New Hampshire Sierra Club Chapter Director. “While there’s been progress to clean up the river, the Merrimack Station coal plant has been polluting it for too long, reversing the progress that has been made. Granite Shore Power and Eversource must be held accountable and follow the law to protect the health of our residents and the local wildlife.”

Granite Shore closed the deal with Eversource in January 2018 to purchase for $175 million the Merrimack and Schiller power plants, the gas-fired Newington Station and two turbines powered by jet fuel in Groveton and Tamworth.

In a statement issued Monday, a spokesman for Eversource denied the allegations made against the utility in the lawsuit.

“As required by state law, Eversource no longer owns or operates Merrimack Station, which was sold more than a year ago,” Eversource spokesman William Hinkle said in a statement. “Our divestiture of generation facilities like Merrimack Station followed an extensive settlement process that included Conservation Law Foundation, as well as many important stakeholders such as the State of New Hampshire. Prior to the sale of the plant more than a year ago, we worked closely with the EPA to meet all environmental permitting requirements, including those cited in CLF’s and Sierra Club’s lawsuit. We deny the allegations and will take necessary actions to respond.”

The only other coal-burning power plant in New England, Bridgeport Harbor Station in Connecticut, is scheduled to close in June 2021, to be replaced by a gas-fired power plant at the same location.