Michael Dourson, President Donald Trump’s nominee to head the EPA’s Office of Chemical Safety and Pollution Prevention, founded and ran a toxicology consulting firm whose work enabled DuPont to avoid providing clean water to people in West Virginia after the company contaminated the area around one of its plants with a dangerous industrial chemical.

In 2000, DuPont was seeking a consulting company to guide the West Virginia Department of Environmental Protection in a delicate project. DuPont had used PFOA to make Teflon and other products and allowed the chemical to seep into water near the plant. The assignment was to help the state set safety levels for PFOA that would determine when DuPont had to provide clean water to residents.

After asking around, a DuPont employee named Timothy Bingman decided Dourson’s consulting firm, Toxicology Excellence for Risk Assessment, was just the right company for the job. “I’ve talked to a number of colleagues that use external toxicity peer review services to see who they like as contractors,” Bingman wrote in an email to his DuPont colleagues that had the subject line “Prospective Contractors for PFOA Review.” “While everyone had a few names to offer, the common theme that emerged was that TERA (i.e. Mike Dourson) was the leading choice.” TERA had “a very good reputation among the folks that are still in the business of blessing criteria,” Bingman explained, going on to describe the company’s ability to “assemble a package and then sell this to EPA, or whomever we desired.”

TERA didn’t disappoint. In 2002, the company helped West Virginia set a safety threshold of 150 parts per billion — a number that stayed in place from 2002 to 2006, and determined whom DuPont was obligated to provide with clean water during this period. That number was 150 times higher than the maximum safety level DuPont’s own scientists had determined in 1988 — 1 pbb — based on internal company research showing that PFOA was toxic to both workers and lab animals.

In May 2016, the EPA set a national drinking water health advisory level for PFOA at .07 ppb — thousands of times lower than TERA’s number. As research has increasingly tied PFOA to kidney and testicular cancer, thyroid disease, immune deficiency and other health problems, several regulatory agencies have arrived at safe drinking water levels that are even tinier fractions of TERA’s. Minnesota, for instance, recently proposed a level of .035 ppb. Vermont set an even lower drinking water standard of .02 ppb. And New Jersey has proposed, though not yet officially set, a level of .014.

Attorneys investigating how the consultants arrived at 150 ppb were unable to obtain the notes from the discussions that led to it. A science adviser at the West Virginia Department of Environmental Protection later admitted that she had shredded documents from the meeting and that the state agency had a “standard practice and policy of destroying documents they anticipate might be the subject of a subpoena in this litigation,” according to a court document.

In 2015, DuPont was found liable for negligence in the case of a woman who developed kidney cancer after drinking water contaminated by PFOA. The company was ordered to pay $1.6 million in damages.

If confirmed by the Senate, the man who helped put forward the extremely high level of PFOA contamination would oversee the implementation of the recently overhauled chemical safety law, the Toxic Substances Control Act. In that role, Dourson could decide which chemicals are subject to the high priority reviews laid out in the new law, how many company-requested risk evaluations the EPA will grant, and how the EPA will use its newly expanded authority to test chemicals. Dourson, who has worked for Dow, will also be in a position to make decisions about the pesticide chlorpyrifos, a chemical manufactured by Dow that the EPA was poised to ban before Trump took office.

Dourson has worked for a variety of other government agencies, industry groups, and companies, including the Petroleum High Production Volume Testing Group, the American Flame Retardant panel of the American Chemistry Council, and the Brominated Flame Retardant Industry Panel.

The EPA issued a press release on Monday with the headline “Widespread Praise for Dr. Michael Dourson.” Among the accolades it presented was one from Samuel M. Cohen, who along with Dourson was a witness for DuPont in the kidney cancer trial over PFOA and also co-authored a paper with Dourson that was paid for by the American Chemistry Council. Cohen described Dourson as “a leader in the field of risk assessment” and “well suited for the position of assistant administrator for the EPA.”

Michael Dourson and the EPA did not respond to a request for comment.