Editor’s Note: The following story first appeared in The Maine Monitor’s free environmental newsletter, Climate Monitor, that is delivered to inboxes for every Friday morning. Sign up for the free newsletter to get important environmental news by registering at this link.

It’s been about 20 years since Minnesota, where the chemical giant 3M is based, first began investigating drinking water contamination around a 3M factory that made the class of chemicals known as PFAS, or per- and poly-fluoroalkyl substances. Around the same time, a lawyer named Rob Bilott was looking into similar pollution from a DuPont factory in West Virginia that was causing the gruesome deaths of nearby cows.

This was the beginning of the public consciousness around what we now call “forever chemicals.” In the wake of these investigations, 3M and DuPont pledged to stop making PFOA and PFOS, which are only two out of thousands of different types of PFAS. Minnesota settled with 3M for $850 million, and DuPont spun off its PFAS business into the company now called Chemours.

Since then, PFAS hotspots have arisen like a game of whack-a-mole in states including Maine, where the chemicals have tainted sludge fertilizer that the state long encouraged for use on farms, and seeped into waterways from military firefighting foam use. Marina Schauffler reported on topics like these in-depth in The Maine Monitor’s recent series “Invisible and Indestructible.” Regulators in places like New England have said that PFAS issues identified so far are only the tip of the iceberg for what’s to come.

3M and DuPont, along with companies that bought PFAS from them, now face scores of lawsuits — from states, towns, fire departments and individuals — accusing them of marketing the chemicals for use in all manner of other household and industrial products, all while knowing the risks. The chemicals persist for decades in the environment and are linked to a range of deadly human health problems. Reporting by The Intercept has shown the 3M knew this and sought to bury it, using a similar playbook to that of Exxon in regards to climate change. Now, state and federal regulation of PFAS is finally on the rise, years after Rob Bilott first began calling for these reforms.

It was likely with this massive legal liability in mind that 3M announced this week it will stop making and using PFAS altogether by 2025. “While PFAS can be safely made and used, we also see an opportunity to lead in a rapidly evolving external regulatory and business landscape to make the greatest impact for those we serve,” said 3M CEO Mike Roman in a press release.

It’s a splashy headline, but what does it really mean? In many ways, the PFAS cat is out of the bag — in Maine and worldwide, the chemicals have been shown to be in drinking water, wastewater, rivers, our bodies, breast milk, crops, soil, compost, food packaging, pets, wildlife. Removing and destroying PFAS is an evolving challenge, and towns, states and water utilities are struggling to figure out how to fund testing and treatment. After 3M’s announcement, some called for the company to go much further in helping fund this effort.

In the U.S., 3M has made the chemicals at factories in Minnesota, Illinois and Alabama — all of which are or have been the subject of drinking water contamination investigations. Illinois is the most recent of these — there, federal authorities stepped in to order a response to PFAS in the Mississippi River after, reporting has shown, state regulators failed to take action for years. And 3M and DuPont are not the only companies that have caused PFAS pollution. Factories that use the chemicals to make their own products — such as Saint-Gobain in New Hampshire — are the subject of similar investigations, and PFAS in firefighting foam has polluted water at scores of airports and military installations.

The chemicals are used in paper-making, which has caused some of Maine’s PFAS pollution and attracted class-action lawsuits, as Mainers begin to ask how the chemicals have harmed their health, land and water, and who will pay to make it right. Maine has not yet joined the huge raft of federal lawsuits against 3M, DuPont and firefighting foam makers, which is being heard in combination in South Carolina, but state Attorney General Aaron Frey said in May that the state planned to do so soon.

Billions in eventual legal settlements with 3M, DuPont and other companies that used PFAS could help cover testing, cleanup and health costs. But those cases may stretch for decades, as has DuPont’s fight with cancer patients and others whose health problems are linked to PFAS in the Ohio River Valley. 3M has also opposed some state PFAS regulations in court — they successfully delayed New Hampshire’s limits for the chemicals by a year, for example, by suing over the rules’ use of Minnesota science on PFAS and pregnant people.

It’s unclear from this week’s 3M announcement what will become of the lawsuits the company is facing for past manufacture and sale of PFAS. “3M will continue to remediate PFAS and address litigation by defending ourselves in court or through negotiated resolutions,” the company said in its release.

It’s also unclear what the future holds for the successor chemicals to PFAS, known as GenX — shorter chains of molecules that have been shown to have some of the same problems and risks. GenX chemicals have already been the subject of at least one settlement, around a Chemours factory in North Carolina. According to New Hampshire Public Radio, 3M declined to answer questions about what its PFAS announcement meant for GenX manufacturing.

“I think the devil is in the details here because PFAS is such a large class of chemicals,” New Hampshire-based PFAS activist Andrea Amico, whose family was exposed to the chemicals in Portsmouth, N.H., told NHPR’s Mara Hoplamazian. “I’m really curious as to how 3M defines PFAS and if they’re truly going to stop making all PFAS chemicals, or if it’s just a certain type of PFAS.”

Other advocates agreed that 3M’s move raised more questions than it answered, both about the company’s next steps and the fate of PFAS throughout society.

“After telling everyone — their neighbors, their workers, and their regulators — that PFAS are safe while poisoning the entire planet, 3M is now pledging to slink out the back door with no accountability. Congress and the courts cannot allow this to happen,” said Scott Faber, a senior vice president with the Environmental Working Group, in comments sent to media. “No one should trust 3M’s commitment to do the right thing. They never have before.”

To read the full edition of this newsletter, see Climate Monitor: As 3M says it’ll stop making PFAS by 2025, what’s next for forever chemicals?.

Reach Annie Ropeik with story ideas at: aropeik@gmail.com.