MADISON, Wis. (AP) — A federal judge has approved a settlement calling for three paper companies that polluted the Fox River and Green Bay with chemicals decades ago to cover hundreds of millions of dollars in remaining cleanup costs.

The deal U.S. District Judge William Griesbach approved Thursday essentially ends a lawsuit over cleanup costs that has been lingering since 2010. Wisconsin Attorney General Josh Kaul said in a news release announcing the approval on Friday that the deal will spare taxpayers about $1.2 billion in remaining costs.

“Generations of Wisconsinites have been affected by the contamination of the Fox River,” Kaul said in the release. “This settlement ensures that final cleanup will be fully funded by those who contaminated the Fox River, and not taxpayers.”

Beginning in the mid-1950s and continuing until the early 1970s, paper companies that produced carbonless copy paper contaminated the river with polychlorinated biphenyls, or PCBS. The chemicals have been shown to cause cancer in animals and neurological development problems in monkeys. Studies have shown they’re probable human carcinogens and could cause similar neurological deficits in humans, according to the EPA.

Cleanup began in 1998 and is expected to conclude next year, according to Kaul’s office. The work entails removing contaminated sediment by dredging as well as keeping it in place with specially engineered caps.

The U.S. and Wisconsin Departments of Justice filed a lawsuit in 2010 against 10 paper companies as well as two municipalities — Appleton and Green Bay — that produced, recycled or discharged the chemicals. The lawsuit demanded that the 12 defendants pay for cleanup, environmental damage and past and future government oversight costs.

NCR Corporation, P.H. Glatfelter Company and Georgia-Pacific Consumer Products LP have covered most of the costs through past settlements in the case.

The parties proposed the deal to Griesbach on Jan. 3. The agreement is intertwined with previous settlements in the case. NCR will continue dredging and cap work under a consent decree the company reached in 2017. Glatfelter and Georgia-Pacific will accept secondary responsibility for ensuring that work is completed.

Meanwhile, Glatfelter will be responsible for long-term monitoring and maintenance along the upper portion of the river and have primary responsibility for those activities along several downstream segments with Georgia-Pacific as a backup. Georgia-Pacific will take primary responsibility for monitoring and maintenance along the rest of the river and the bay of Green Bay with Glatfelter as backup.

Glatfelter also agreed to reimburse the EPA and Wisconsin Department of Natural Resources’ future response costs, including oversight costs. NCR and Georgia-Pacific will assume backup responsibility for those costs. Glatfelter also will pay EPA $20 million to help defray about $38.5 million in unreimbursed response costs dating back to September and pay the U.S. Department of the Interior $500,000 for federal, state and tribal use in environmental restoration.

Attorneys for NCR and Georgia-Pacific didn’t immediately respond to emails seeking comment. David Mandelbaum, an attorney for Glatfelter, said he was traveling and had no immediate comment.

Glatfelter posted a news release on its website on Jan. 3 announcing it had entered into the agreement, saying the company would no longer face uncertainty in Fox River cleanup except for government oversight costs. The company noted it had reserved $45 million for that purpose.