State regulators will ask a wide swath of businesses, manufacturers, landfills and municipalities to start monitoring for a class of industrial chemicals known as PFAS, a major health and environmental threat across the country.

The results could offer one of the most comprehensive understandings yet of exactly where PFAS contamination is still coming from. The substances, known as "forever chemicals," do not break down in the environment.

Monitoring would begin sometime this winter, said Katrina Kessler, commissioner of the Minnesota Pollution Control Agency (MPCA), which announced its monitoring plan on Tuesday. The agency will accept public comments on the plan until Dec. 20 and could potentially revise it.

The monitoring will focus not only on finding and reducing PFAS contamination in rivers and lakes, but also identifying sources of air, soil and groundwater pollution, Kessler said.

"It is a statewide challenge," she said.

Monitoring would be voluntary, for now. The MPCA will ask several hundred businesses and municipalities to work with the agency to start testing for PFAS — per- and polyfluoroalkyl substances — some of which cause cancers, thyroid problems and hypertension. If the voluntary monitoring doesn't work to identify and reduce pollution, Kessler said the agency will pursue mandatory regulations.

"We are trying to work in partnership, but if necessary we will take action," she said.

The compounds, prized for their water and stain resistance, have been used since the 1950s in untold numbers of consumer products such as cellphones, mascara, brake fluid and even hospital gowns. They were common in firefighting foam used in airports and military bases.

The chemicals were pioneered by Maplewood-based 3M Co. The company struck a deal in 2018 to pay the state $850 million to settle a lawsuit over the contamination. But the sources of PFAS pollution now extend well beyond one company.

As a pollutant, the compounds not only never break down, but they've also spread to every corner of the globe and have been found in Arctic polar bears as well as in local food wrappers and lettuce. There is a global movement to restrict use of all PFAS.

The MPCA will ask nearly 200 companies and manufacturers considered to be the most likely sources of PFAS pollution to begin testing. It will also ask dozens of municipal wastewater treatment plants and landfills that serve as conduits of the pollution to test for it. Those businesses and municipalities would pay for the costs for testing.

The state has also been expanding its own testing for several years, finding dangerous concentrations of the compounds leaching into rivers and groundwater downstream of wastewater treatment plants and landfills.

"One of the things that comes up again and again is that wherever we look for PFAS, we find it," said Sophie Greene, the MPCA's PFAS coordinator.

Industrial chrome platers, including one in Minneapolis, have historically used high concentrations of PFAS that have escaped into the environment, Greene said. Car shredders are also common sources.

"The interiors of automobiles are coated with PFAS," Greene said. "It's in the upholstery, which makes the material stain, water and soil resistant. When the cars are shredded it can mobilize the PFAS and we see runoff."

The MPCA will model some of its monitoring efforts after the state of Michigan, which has successfully reduced PFAS contamination coming from wastewater treatment plants after starting a voluntary monitoring program.

It is a vital and critical step for the state to measure and find where sources of PFAS pollution are coming from, said David Andrews, senior scientist for the Environmental Working Group, which has been pushing states and the federal government to regulate PFAS.

But it is also unclear why it has taken so long to begin monitoring for PFAS, when environmental and health concerns about the substances have been known for years, he said.

"This would start baseline sampling in 2022 and 2023, so Minnesota would still be a ways out until the results come in, and that's what is needed to reduce some of these discharges," Andrews said.

Greg Stanley • 612-673-4882