The Challenge of Removing Toxic PFAS ‘Forever Chemicals’ from Drinking Water

What’s in your faucet can be a dangerous thing. If you’re like an estimated 200 million Americans, every time you turn on the tap, a host of contaminants come out with the water. Among these are trace amounts of PFAS, short for per- and polyfluoroalkyl substances. Also known as “forever chemicals”—because that’s pretty much how long they linger in the environment—exposure to these ubiquitous manufacturing chemicals have been linked by the U.S. Environmental Protection Agency (EPA) to potential health consequences including decreased fertility, hypertension in pregnant people, increased risk of certain cancers (especially kidney cancer), developmental delays in children, hormonal irregularities, elevated cholesterol, reduced effectiveness of the immune system, and more.

PFAS are used in hundreds of products, including shampoos, soaps, non-stick pots and pans, food packaging, fire-fighting foam, fabrics, and carpeting, and they’ve recently been detected in toilet paper and menstrual products. But it’s PFAS in the water supply that has long been of the greatest concern, simply because while our encounters with some products may be infrequent, we all need water to survive.

On Mar. 14, the EPA at last took action, announcing a new proposed regulation to eliminate six of the most common and dangerous PFAS from the national water supply. Following a 90-day public comment period, the rule will be formally promulgated by the end of the year, and water systems nationwide would then have three years to install filters or change the wells and other sources from which they draw their water to ones that are free of PFAS.

“We would expect water systems to be coming into compliance with the new regulation by the end of 2026,” says Eric Burneson, the EPA’s director of standards and risk management.

Human beings have been living with PFAS ever since they were first developed in the 1940s, and over the decades, thousands of different variations of the chemicals have been invented. The two most common and dangerous are known as PFOA and PFOS, both of which have been linked to the development of cancer. As long ago as 2002, companies under pressure from the EPA and advocacy groups began agreeing to phase out PFOS in all products, followed by PFOA in 2015. But both types of PFAS linger in the environment—in soil near manufacturing plants, in durable products manufactured before the bans, in groundwater, and in wells.

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“Even putting products in landfills doesn’t help, because you have leachate that contaminates groundwater,” says David Andrews, senior scientist at the advocacy organization Environmental Working Group. What’s more, Andrews says, uncounted imported products are manufactured in countries that have not banned PFOA and PFOS, meaning a steady flow of the chemicals continues into the U.S.

For these reasons, the EPA made PFOA and PFOS the first two PFAS on their new hit list, setting their maximum contaminant level (MCL) in the water supply at four parts per trillion (ppt). Ideally, the level would be zero ppt, but four is the lowest amount that can be reliably measured with existing technology. The four other PFAS the EPA targeted are known as PFNA (with an MCL of 10 ppt), PFHxS (9 ppt), PFBS (2,000 ppt), and FHPO-DA (10 ppt).

Selecting those four out of the thousands of PFAS that remain was relatively easy, since they are indicator chemicals: where one of them is found, the others usually lurk, too. “They often co-occur with one another,” says Burneson. Filter out one of the bad guys, and you likely nab the other three as well.

What’s more, while PFNA, PFHxS, PFBS, and FHPO-DA are not considered as deadly as PFOA and PFOS, they are by no means low-risk. “They are the most common other [PFAS] contaminants that have also been very well studied,” says Andrews. “They have strong documented health harms.”

Eliminating those six PFAS alone could have huge knock-on effects when it comes to public health. “We think there will be thousands of deaths avoided and tens of thousands of illnesses avoided once this rule is fully implemented over the years,” says Burneson.

While EPA action against PFAS in the water supply has long been lobbied for by advocacy groups, it took until recently before both the political will and wallet came together to make the action possible. On Oct. 21, 2021, EPA Administrator Michael Regan announced an agency-wide “strategic roadmap” to restrict the use of PFAS and hold polluters accountable—at last putting the chemicals in the federal government’s crosshairs. Shortly after, on Nov. 15, 2021, the Infrastructure Investment and Jobs Act became law, including $9 billion earmarked for the EPA to deal with emerging contaminants, including PFAS.

“The public water systems will be required to take what actions they need to monitor and install treatment if necessary,” says Burneson. “And now there is an historic amount of funding for this.”

There is less money there than meets the eye, however. Even if the entire $9 billion were used to eliminate PFAS from the water supply—and it won’t be, since some of that funding will go to mitigating other pollutants—local water suppliers will incur some as-yet undetermined costs in installing filtration or switching to different wells or aquifers. But that will not necessarily hit consumers hard. Ten states, including New Jersey, New York, Massachusetts, Michigan, and Wisconsin, already have regulations in place banning or at least limiting PFAS in water supplies, and, according to Andrews, water bills have not been affected much.

“Based on the available technology and based on what we’ve seen in states that have set more stringent limits for PFAS contamination, there has not been a significant increase in rates,” he says.

Until the EPA rule is fully in effect, consumers willing to incur some expense can jump out ahead of the government and at least partly control the PFAS coming out of their own faucets. Getting your water tested for PFAS is possible, but it’s not cheap. “If someone wants to incur the cost of having their water tested, we [the EPA] do maintain lists of approved laboratories,” says Burneson, “but there would be some expense for that.” In New York state, for example, local labs charge from $300 to $600 for the service.

Simple home charcoal water filters‚ which can run from $50 to $200 per sink, can help strain out some PFAS—but not all of them. Reverse osmosis filters, which force water through a semi-permeable membrane, are more expensive—some can exceed $500—and also let some PFAS through. “The filters are not as effective at [eliminating] some of the shorter chain PFOS compounds,” says Andrews. “In testing, they don’t remove all of the contamination. Of course, we’d like to see it get to the point where drinking water standards are in place, and people don’t have to worry about installing filters. Everyone should have access to clean and safe drinking water.”