GEOFF BENNETT: The Trump administration is moving to roll back limits on some PFAS, the toxic forever chemicals found in the drinking water of millions of Americans.

The Biden era rule set the first national drinking water limits for several PFAS compounds, but industry groups argued the standards were legally flawed and too costly to meet.

EPA Administrator Lee Zeldin says the chemicals still need to be addressed, but that the previous administration overreached.

LEE ZELDIN, Environmental Protection Agency Administrator: There are two ways to act on PFAS.

You can do it the way that the last administration did, where a regulation would be rushed out the door.

Certain steps were skipped as the law had required, and water systems were giving deadlines that many of them have communicated to us that they're going to have trouble meeting.

And we left the rule open to be struck down in court.

That approach makes for a good press release, and doesn't make for cleaner water.

GEOFF BENNETT: William Brangham has been reporting on this and joins us now.

So, William, before we get into these changes, remind us what these chemicals are and why scientists are so concerned about them.

WILLIAM BRANGHAM: PFAS are these remarkably resilient, durable chemicals.

I mean, they're kind of a wonder of chemistry.

They are in dental floss and couches and Gore-Tex and nonstick pans.

They have helped revolutionize certain industries.

But they are also some of the most insidious pollutants on the planet.

We call them forever chemicals, as you mentioned, because they just do not break down out in nature, and they have spread everywhere on Earth.

I can't think of a place that they have tested and looked for them where they have not found them all over the globe.

They get into us by us eating food that has PFAS in them, by products in our own lives, and by drinking water that is contaminated with that.

I mean, it is estimated that almost all of us, humans on Earth, have PFAS building up in our bodies.

That's the concern.

GEOFF BENNETT: And the Biden administration sought to restrict the amount of these chemicals in drinking water.

We heard the EPA administrators say that, yes, this is an issue, but they still are overturning the Biden era rule.

So what's the EPA's argument?

WILLIAM BRANGHAM: They argued that the Biden administration went too far, too fast, and that, according to the Clean Water Act, they didn't follow all the appropriate procedures, and thus these rules could be struck down in court, which the industry was trying to do.

The chemical industry and associations of water municipalities have argued that the cost of filtering PFAS out of drinking water, which we can do, they argued that it was much too expensive and that the benefits were just not there for the public.

The chemistry industry has also argued that they have really reduced the use of PFAS in a lot of different products, but that certain types of PFAS are still essential to certain industries and that they have got to keep them.

GEOFF BENNETT: So, what have the supporters of the Biden era rule said in response?

WILLIAM BRANGHAM: I mean, as you can imagine, Geoff, they are livid.

They argue, yes, it might be expensive to filter chemicals out of the water, but that is a cost that the companies that polluted the water in the first place ought to be paying, and that the benefits, that, if we get reduced levels of cancer and thyroid disease and obesity and all these other health implications that are linked to PFAS, that is worth the cost.

This is how Ken Cook, who runs the Environmental Working Group, put it about this move today.

He said -- quote -- "The Trump EPA is caving to chemical industry lobbyists and water utility pressure.

And, in doing so, it is condemning millions of Americans to drink contaminated water for years to come.

The price of this decision will be paid by ordinary people in the form of more PFAS-related diseases."

The interesting thing about this, Geoff, is that the criticism is not just coming from environmental groups.

A big slice of the president's own base, the MAHA, the Make America Healthy Again, movement spearheaded by RFK Jr., they have pushed very hard to get chemicals out of our food and water.

And they have been resistant to any attempt to roll back rules about things like this.

In fact, RFK Jr.

was at this announcement with the EPA administrator yesterday.

And, at times, he sounded like the RFK Jr.

of old, the sort of champion decrying chemical contamination of our water supply.

But he and this administration argue, they will protect us from PFAS, but just not the way the Biden administration did.

That is the test.

We have yet to see how they're going to do it.

GEOFF BENNETT: William Brangham, thanks, as always, for this reporting.

Appreciate it.

WILLIAM BRANGHAM: Thanks, Geoff.