(The Hill) — The Biden administration on Wednesday set the first-ever national limits for toxic and pervasive “forever chemicals” in drinking water. 

The administration’s action seeks to reduce the amount of chemicals belonging to a class known as PFAS in drinking water. 

These substances, which have been used to make waterproof and nonstick products, have seeped into a significant portion of the nation’s water. They have been linked to increased risk of prostate, kidney and testicular cancer, weakened immune systems, developmental delays in children, decreased fertility and high blood pressure in people who are pregnant.

They have been nicknamed “forever chemicals” because they tend to persist in nature instead of breaking down. 

While some states had previously set their own limits for the amount of PFAS, which stands for per- and polyfluoroalkyl substances, that can be in drinking water, there was previously no restriction that applied nationwide.

The EPA said its rule will reduce exposure to these substances for about 100 million people, prevent thousands of deaths and reduce tens of thousands of serious illnesses. 

“Drinking water contaminated with PFAS has plagued communities across this country for too long,” EPA Administrator Michael Regan said in a written statement. “Today, I am proud to finalize this critical piece of our (PFAS) Roadmap, and in doing so, save thousands of lives and help ensure our children grow up healthier.”

The rule is only expected to apply to public drinking water systems and not the water of people who use private wells. The agency estimated that between 6% and 10% of the nation’s drinking water systems will have to take action to meet the standards.

Water systems will have three years to monitor for the chemicals. If they find levels above the EPA’s standards, they will have to implement a system to reduce them within five years.

In addition to the limit on PFAS, the administration announced that $1 billion will be available through the bipartisan infrastructure law to help both water systems and private wells address PFAS. A lawsuit between polluters and drinking water providers were recently settled, with company 3M expected to pay more than $10 billion, while DuPont and its spinoffs are expected to pay a combined $1.2 billion. 

While there are thousands of types of PFAS, the EPA’s rule applies to just a handful. However, some of the technologies that are used to filter them from drinking water may also reduce the presence of other types.

The EPA set legal limits for two of the most toxic — and most notorious — types of PFAS, called PFOA and PFOS, at 4 parts per trillion for either compound. 

A “part per trillion” is about equal to one drop of water in 20 Olympic-sized pools. 

The agency said that for these two compounds it was also declaring that there is no safe level — setting a non-enforceable health goal at zero. 

For other PFAS, known as PFNA, PFHxS and GenX, the agency set the legal limit at 10 parts per billion. 

As PFAS can be found in mixtures, the agency is also setting a limit on any mixtures of two or more of GenX, PFNA, PFHxS and another substance called PFBS.