DuPont and Chemours (the US chemical giant’s former Performance Materials segment) have agreed to jointly pay $670.7 million in cash to settle out of court around 3,550 personal injury lawsuits related to discharges of perfluorooctanoic acid (PFOA) from the former DuPont Washington Works at Parkersburg in the US state of West Virginia.

The payout, which covers all claims, both decided and still pending, will be borne equally by the now separate companies under an agreement. All the cases were part of multi-district class action litigation in the US state of Ohio. DuPont has lost all three lawsuits heard to date, and juries have awarded the plaintiffs a total of $19.7 million in damages. Around 39 additional cases had been slated to go to trial alone in Ohio this year.

In the consolidated class action suit, the plaintiffs charged that contamination of their drinking water supplies with PFOA was responsible for their cancers. Some members of the class also sued DuPont individually. The chemical group agreed not to challenge whether PFOA could have caused the illnesses. Some years ago, when the issues with the fluorochemical then used to produce its Teflon brand non-stick pan coating became public, DuPont replaced it in the production process.

In the 2015 split-up of the Delaware-based group, the relevant business was spun off into Chemours. Although Chemours was not named in the lawsuits, an agreement with its former parent foresaw it sharing the financial burden of the litigation. DuPont also unloaded several million dollars’ worth of liabilities onto the new standalone company. At the time, Chemours estimated that the cleanup costs stemming from PFOA contamination at its inherited sites could total $14 million.

To address potential PFOA liabilities going forward, the two companies have agreed that during each year of the five-year period the settlement covers, Chemours will pay up to $25 million. Once that threshold is reached, DuPont will pay up to $25 million more. After five years, DuPont will have no further commitment to fund PFOA-related costs.

The chemical group, which is in the process of merging with compatriot Dow, also faces a lawsuit filed in New Jersey in December 2016, alleging that a local production complex was transferred to Chemours to avoid clean-up costs exceeding $1 billion. The chemical producer was said to be in violation of the state’s Industrial Site Recovery Act.

Last summer, a Dutch public prosecutor launched an investigation into the use of PFOA and DMAc at two former DuPont chemical plants near Dordrecht, now part of Chemours. The investigation followed probes by the country’s public health institute RIVM and its social affairs ministry into claims that the US chemical producer’s use of the substances C8 and DMAc had led to health problems locally. The authorities said they would decide whether to press charges when all evidence has been reviewed.