– The U.S. Environmental Protection Agency (EPA) outlined a national plan Thursday to deal with public health risks of pollution caused by a family of chemicals used in many household products, including those produced by Minnesota-based 3M Co.

Drinking water and groundwater pollution caused by perfluoroalkyl and polyfluoroalkyl substances — known as PFAS — has been associated with cancer and other health risks, including immune system, liver and thyroid problems.

The World Health Organization considers PFAS possibly carcinogenic to humans, and the EPA itself says there is “suggestive evidence” that two of the mostly widely used kinds of PFAS “may cause cancer.”

Acting EPA Administrator Andrew Wheeler told reporters Thursday that the EPA initiative is moving toward classifying PFAS as a hazardous substance under the EPA’s Superfund program, allowing the EPA to clean up sites and force polluters to pay.

When asked why the EPA is taking so long to classify PFAS as hazardous, Wheeler said the process takes time because the move may be challenged in court. “None of these processes can be done overnight,” Wheeler said.

Wheeler outlined what he called a “historic moment” in the agency’s efforts to address an “emerging chemical of concern.”

PFAS have a long history in Minnesota, where 3M Co. invented the original nonstick compounds in the 1950s, manufacturing them at its Chemolite plant in Cottage Grove. The chemicals, which don’t break down, were used in a range of consumer products such as Teflon and Scotchgard.

Last year, the Maplewood-based manufacturer agreed to pay Minnesota $850 million to settle a PFAS pollution lawsuit brought by then-Attorney General Lori Swanson.

3M denies that PFAS are hurting people. But the company faces suits from public officials in multiple states and is the subject of a private class-action lawsuit brought on behalf of people allegedly suffering from PFAS-related health problems.

Following Wheeler’s news conference, the company issued a statement supporting a national standard for two of the most frequently used PFAS chemicals. “We support regulation rooted in the best-available science and believe that this plan may help prevent a patchwork of state standards that could increase confusion and uncertainty for communities,” it said.

Environmental and consumer groups said the EPA’s plan doesn’t go far enough. They quickly challenged Wheeler’s decision not to push immediately for a national standard or other measures that will to lower allowable amounts of PFAS in drinking and groundwater. The nonprofit Environmental Working Group called the EPA strategy a “recipe for more contamination.”

No mandatory national standard exists for allowable levels of PFAS, only a federal advisory level. But that level — 70 parts per trillion — is much higher than levels known to cause health problems, some researchers say. Wheeler said Thursday that EPA feels “70 parts per trillion is a safe level for drinking water.”

Minnesota’s groundwater safety standards for PFOA and PFOS are twice as restrictive as the federal recommendation.

Other states impose even stricter limits. But Minnesota’s limits, like the federal limits, are “advisory rules, not regulatory standards, ” said Jim Kelly, the state’s manager of environmental surveillance and assessments.

It is difficult if not impossible to compel a company to take corrective action in advisory situations, Kelly explained.

Kelly also noted that state personnel did not find any unusual cancer rates or “birth outcomes” around Cottage Grove. Other health issues such as immune system, liver and thyroid conditions are not required to be reported and so are not able to be assessed.

One thing that would come with a Superfund designation would be mandatory constant monitoring of PFAS levels.

“The lack of a federal standard is not an indication of safety,” David Andrews, a senior scientist at the Environmental Working Group, told the Star Tribune. “The lack of a federal standard is a failing in the process to incorporate modern science.”

U.S. Sen. Tina Smith, D-Minn., who served as lieutenant governor during the state’s PFAS lawsuit against 3M, noted the need for speed, saying in a statement that “it is crucial that there is no delay in ensuring that Minnesotans have access to both clean and safe drinking water.”

Sen. Amy Klobuchar, Minnesota’s senior senator and a candidate for the Democratic presidential nomination, called the new PFAS plan “a missed opportunity by the EPA and Acting Administrator Wheeler to step forward and protect Americans’ drinking water from PFAS contamination.”

Wheeler said EPA will recommend mandatory PFAS toxicity standards by the end of the year but could not say how long the process of approval and implementation would take. It could take years.

“Our goal is to close the gap as quickly as possible,” he said.

Part of the new initiative will be measuring the extent of PFAS presence in the environment. Wheeler promised that in the meantime, the agency would continue to take enforcement actions using the health advisory standard.

The Minnesota Pollution Control Agency (MPCA) said the plan won’t affect PFAS testing and mitigation work ongoing in the state. And it also won’t affect the state’s settlement with 3M for damage from PFAS, said MPCA spokesman Walker Smith. The settlement money will finance drinking water and natural resource projects that haven’t yet been developed.

Most of the projects will likely be in the eastern Twin Cities, where 3M is located where it disposed of contaminated waste at four dump sites in Washington County.

The MPCA and Minnesota Department of Health have been investigating PFAS contamination since 2002, when 3M stopped producing the chemicals. PFAS were discovered in drinking water in eastern Twin Cities in 2004. Efforts have been underway since then to measure and address the ubiquitous contamination, and understand the health impacts.

In 2017, the state Department of Health revised the health-based values for two key PFAS chemicals, PFOA and PFOS, to 35 parts per trillion and 27 parts per trillion, respectively.

“We’re ahead of most states already,” said the MPCA’s Smith. “We certainly approve of the EPA’s decision to regulate these chemicals, and it will make a more level playing field across the country.”