PROVIDENCE – Rhode Island will receive a minimum of $25 million from Monsanto Company and its affiliates under a settlement resolving the state’s claims that the chemical giant contaminated waterways and natural resources with toxic polychlorinated biphenyls, or PCBs.

Attorney General Peter Neronha announced the deal Monday. The total payout could climb as high as $62.5 million, depending on the outcome of ongoing indemnity litigation between Monsanto and the companies that purchased its PCBs.

Funds from the settlement will be directed toward cleaning up contaminated water bodies and preserving the state’s natural resources.

“Today we hold Monsanto accountable for the longstanding harms we allege were caused by its production of PCBs and misleading the public about these toxic chemicals,” Neronha said. “While the production of PCBs stopped in the 1970s, their lasting effects have endangered Rhode Island’s natural resources, as well as public health.”

Monsanto, best known as the maker of Roundup weed killer, was acquired by German agrochemical giant Bayer in 2018 for $63 billion. On the same day as the Rhode Island announcement, Monsanto also reached a $108 million settlement with Michigan over similar PCB-related claims, according to Michigan Attorney General Dana Nessel.

A Bayer spokesperson said the two agreements are the 11th and 12th such state settlements the company has reached, with five state cases still pending.

 In a statement emailed to ecoRI News, the company said, “Monsanto has reached settlement agreements with Rhode Island and Michigan to resolve all claims relating to PCBs, a legacy product the company voluntarily ceased producing in 1977.

“Both states agreed to cooperate with Monsanto in this action, having determined there is a substantial basis for the company’s pending indemnity case and a significant portion of the liability should be borne by Monsanto’s former PCB customers.”

Rhode Island is set to receive an initial payment of $12.5 million in June, with the potential for up to $50 million more tied to the outcome of indemnity proceedings.

PCBs are synthetic industrial chemicals that were widely used for decades in electrical equipment, hydraulic systems, caulking, and plastics before the United States banned them in 1979. Monsanto voluntarily halted PCB production two years earlier, in 1977. The chemicals are highly persistent in the environment — they resist natural breakdown and have been detected in several Rhode Island waterways, including the Woonasquatucket and Blackstone rivers, Mashapaug Pond, and Narragansett Bay.

The compounds build up in animal tissue and have been found in eagles, osprey, herons, fish, and other wildlife across the state. In humans, PCB exposure has been linked to cancer and a range of other serious health conditions.

State officials said that had the case gone to trial, Rhode Island would have argued that Monsanto knowingly misled consumers, the public, and government agencies about the dangers of PCBs — even as internal scientific reports documented their harmful effects.