DuPont and plaintiff attorneys have agreed in principle to settle about 3,550 lawsuits tied to its ongoing water pollution case that is alleged to have caused numerous types of cancers to those consuming the water in Ohio and West Virginia.

Along with Chemours, it will pay $670 million in cash. The two will split the settlement. DuPont and Chemours separated in 2015. Chemours now makes C-6, which replaced C-8.

Both companies deny any wrongdoing. The agreement will settle all the claims, even those three that have been tried in court and that have resulted in penalties of $20 million. All went against DuPont.

DuPont stopped using C-8, which goes into the making of Teflon, a decade ago.

“We look forward to working with DuPont to finalize this settlement and get these injured class members paid as quickly as possible,” said plaintiffs’ lawyer Rob Bilott, in a statement.

The case first came about in 2001 when local residents along the Ohio River that separates Ohio and West Virginia complained of illness. DuPont subsequently agreed to fund medical research into whether its C-8 chemical was in fact leading to these cancers.

Beginning in 2011 and throughout 2012, those experts concluded that C-8 was “more likely than not” to cause such conditions as ulcerative colitis, kidney cancer, thyroid disease and testicular cancer.