Gary Paulson has always wished he knew more about the toxic chemicals that once leached into his well from a landfill 1,000 feet from his Lake Elmo home.

At 71, he has survived four bouts of cancer and mused often about neighbors who also fell ill over the years. "Thank God Karen is OK," he said of his wife.

Paulson and other east metro residents from Woodbury to St. Paul Park, who for decades have lived with contaminated drinking water, are being swept up in what may prove to be the final reckoning between the state of Minnesota and one of its oldest, most esteemed corporations.

Unlike the residents, 3M Co. knew a great deal about those chemicals, it turns out. They're compounds it manufactured and dumped at several sites around Washington County, according to documents filed last week in a lawsuit by Minnesota Attorney General Lori Swanson.

A stark report from a Harvard University researcher hired by Swanson concludes that 3M knew about the chemicals' possible health risks as early as the 1970s, and purposely avoided doing the research that would have provided the state and the company's neighbors with more information about them.

The company "either closed its eyes to the evidence, or chose purposely not to find it," said Philippe Grandjean, a leading researcher on the chemicals who reviewed many of the thousands of internal 3M documents. "It's remarkable," he said, "how little and how late 3M's knowledge was publicly disclosed."

3M insists, as it has for years, that there is no evidence that its chemicals, known as PFCs, caused harm in Minnesota or anywhere else. It has produced its own batch of expert reports, which say none of the science has proved a "causal" relationship between PFCs in the environment and human disease.

Barbara Beck, the company's environmental consultant, said in her report that Grandjean was "attributing motives to 3M without evidence."

A dispute over health risks, contaminated drinking water and pollution of the Mississippi River is the crux of the lawsuit Swanson filed to make the company pay for what her experts estimate is $5 billion in damage to Minnesota public resources. After years of delay, the eight-year-old suit is finally set for trial in February in Hennepin County.

Grandjean's report, and a huge trove of internal 3M documents obtained by the attorney general, crack open the history of 3M's internal research and correspondence about PFCs, the class of chemicals it invented. The report gathers together the global research on PFCs, concludes that they pose "a substantial present and potential hazard" to human health, and lays out in detail the history of what 3M knew and when it knew about the potential consequences of its product.

A second report, compiled by University of California resource economist David Sunding, concludes that residents of Washington County experienced elevated rates of cancer, infertility and low birthweight babies because of PFCs in their water.

3M disputes Sunding's research as well, but nonetheless, his findings are reverberating throughout the county and reigniting long-held fears.

"It's stunning," said Eileen Weber, who teaches at the University of Minnesota nursing school, lives on 5 acres in Denmark Township, and is a longtime Minnesota Health Department citizen adviser on toxic exposures.

"Now we have this report that shows this may be a lot more harmful than people were led to believe," she said. "What happens now?"

Blockbuster chemical

The state's lawsuit is one of many pending against 3M and other manufacturers over PFCs, a blockbuster invention that was used in Teflon and Scotchgard and became among the most widely used chemicals in the world. Earlier this year DuPont settled hundreds of personal injury suits for a total of $671 million for contaminating drinking water around its Teflon plant in West Virginia. Last year, the city of Lake Elmo sued 3M to recoup cleanup costs to its drinking water system.

3M made PFCs at a plant in Cottage Grove starting in the late 1940s, and disposed of them for decades at sites in Lake Elmo, Cottage Grove, Oakdale, Woodbury and St. Paul Park. Chemical waste leached into groundwater, creating what is now a 100-square-mile plume that has contaminated city and private wells throughout the area.

In an agreement with the U.S. Environmental Protection Agency, 3M and other manufacturers phased out the chemicals starting in 2000, even though "3M believes these chemicals present no harm at the levels they are observed in Minnesota," a company attorney said.

Since the water contamination was first documented in the mid-2000s, local communities have switched to clean sources for drinking water, and homeowners with private wells have been provided bottled water and filtration systems. 3M paid for the work through an agreement with the Minnesota Pollution Control Agency, and many local residents felt the risks had been addressed.

In recent years, however, the ground has shifted. Research funded by the DuPont legal settlement found that PFCs are more dangerous to people than previously thought. The EPA greatly lowered the health-safety limits it recommends for PFCs in drinking water. And then in a recent court filing, Swanson made public the Sunding study that found significantly higher health risks for Washington County residents.

Grandjean's report, as some nonprofits and news reports have done in the past, argues that 3M executives knew or suspected these risks long before they disclosed them to the public. Specifically, he cites statements made in 1998 by Richard Purdy, a 3M environmental scientist, who warned that for 20 years the company had stalled on collecting environmental data on one chemical, PFOS.

In one document, Purdy wrote "PFOS is the most onerous pollutant since PCB," referring to another toxic chemical, banned in 1979. "And you want to avoid collecting data that indicates it's probably much worse."

A year later Purdy resigned, saying, "For me it is unethical to be concerned with markets, legal defensibility and image over environmental safety."

3M officials say Purdy later recanted his statements. In a document they provided from another 2015 court case, Purdy said, "Ultimately, I am very proud of 3M's investment in science and the work it performed on [PFCs]."

Grandjean, however, says Purdy's case was part of a larger pattern. He cites numerous times that 3M managers and scientists ignored or dismissed findings, and were told not to e-mail or write down results that pointed to potential risks. In 1975, a 3M scientist told an outside researcher "not to speculate" when he called to ask whether Scotchgard might be the source of PFCs that he found was widespread in human tissue samples.

From animal studies carried out in the 1990s, 3M knew that PFCs were transmitted through maternal milk, Grandjean said. "It is likely that lactating human females would also transfer PFOS to milk," the company's report found. But 3M did not appear to follow up on the "potential implications," Grandjean said.

Grandjean has recently published work showing that infants responded poorly to early vaccinations if they were breast-fed by mothers with PFCs in their blood — research that helped persuade Minnesota health officials this year to push the state's PFC safe drinking water guidelines even lower those of the EPA.

'Abuse of power'

Beck, one of 3M's experts, said drinking water guidelines are precautionary, not a true reflection of health risks. She also said that Grandjean "mischaracterized" the company's past actions.

"While 3M has studied PFCs for decades and published much of its early work, it appropriately increased its efforts … in the 2000s," when the chemicals were found to be widely distributed in people and wildlife, she said. Also, she said, it was not until the 1990s that advances in chemistry made it possible to reliably measure PFCs in humans.

3M also argues that Swanson's lawsuit oversteps Minnesota's legal authority. The suit "is an abuse of the power given to the Attorney General," said 3M's lead attorney, William Brewer III. "3M has worked closely with regulators and community stakeholders to address the [risks of] chemicals it has not produced or used in Minnesota in more than a decade."

The company, he said, is eager to defend its record of corporate stewardship in court.

Even before the trial opens, the legal disclosures are heightening concerns in the affected communities.

"It's a little frightening," said Rep. Keith Franke, R-St. Paul Park, who owns the local Park Cafe. He recalled town hall meetings last summer where people were visibly worried about their children.

"There was a pregnant woman there with a toddler," Franke said. "She was like, 'I have a private well, should I be concerned?' And they were like, 'No, follow the guidelines.' "

Now, Franke worries the state may have a far more serious health concern than it knew.

The Washington County Landfill near Gary Paulson's house is closed now, but Paulson said he still wonders if PFCs played any role in his cancer. Thinking about what they might yet do to his four kids brings him to tears.

"I worry about it," he said.

Josephine Marcotty • 612-673-7394