A consumer guide for dealing with harmful PFAS being detected nationwide, including Wisconsin

If you’ve been hearing more about PFAS in Wisconsin waters, it’s because testing is increasingly detecting those harmful chemicals. As of Nov. 18, the Wisconsin Department of Natural Resources was monitoring PFAS contamination at 91 sites from French Island in the west to Peshtigo in the east.

What can you do if you have PFAS in your water? The answer is complicated. Here’s what to know about navigating threats from the chemicals.

What are PFAS?

PFAS, or perand polyfluoroalkyl substances, are a class of more than 12,000 humanmade compounds. They accumulate in the environment and human bodies over time and do not easily break down, which is why some people call them “forever chemicals.” Increased testing is revealing PFAS in public drinking systems, groundwater and surface waters nationwide.

Why should I care about PFAS?

Scientists haven’t studied most PFAS deeply, but they link two of the most widely researched, PFOA and PFOS, to a range of health problems. Those include altered hormone levels, decreased birth weight, digestive inflammation and ulcers, high cholesterol, hypertension in pregnancy, kidney and testicular cancers and reduced vaccine effectiveness in children.

Where do PFAS come from?

PFAS are ubiquitous in consumer and industrial products, such as fabric stain protectors, firefighting foam, food packaging, lubricants, nonstick cookware, paints and waterproof clothing. Most Americans encounter them through the foods they eat, dust, and handtomouth contact with PFAStreated products. But you probably wouldn’t know it, because the chemicals are often odorless, colorless and tasteless.

Tap water is typically the main source of exposure for people living near contaminated sites. But that doesn’t mean you have to stop showering. Little PFAS enter the body through the skin, according to the U.S. Centers for Disease Control and Prevention. Bathing and washing dishes with PFAScontaminated water is unlikely to significantly increase exposure, the agency says.

How much PFAS is harmful?

Virtually no amount of PFAS is safe for consumption, according to the U.S. Environmental Protection Agency. In June, the agency updated draft health advisories for PFOA and PFOS. It warned against consuming more than 0.004 parts per trillion (ppt) and 0.02 ppt of the two compounds, respectively. That equates to about 4 drops and 20 drops of water in 1,000 Olympicsized swimming pools.

How do I know if my water is safe to drink?

The answer depends on who you ask and where you live. The EPA sets standards for public drinking water systems, which must treat water to within acceptable limits for contaminants. No national standard yet exists for PFAS, so many states have stepped in to set their own. Others have none.

Wisconsin this year established a drinking water standard of 70 ppt for PFOA and PFOS individually and combined, far above the draft EPA health advisory. Multiple Wisconsin public water systems have detected PFAS above or within the state’s standard. Utilities must publish their test results, which you can view online.

What if I have a private water well?

Neither the EPA nor the state regulates private water wells. That means the 1.7 million Wisconsinites who use them bear responsibility for testing and treating their own water for PFAS or other contaminants. The Department of Natural Resources offers general recommendations for well testing here. Many laboratories can test water for PFAS for a fee.

How can I treat my water?

Multiple filtration systems can remove PFAS from tap and well water. You can install them where water enters a house or building or on a specific fixture. Treatment methods include granular activated carbon, ion exchange resins and reverse osmosis.

“We know that the lower the levels of PFOA and PFOS, the lower the risk,” EPA environmental engineer Jonathan Burkhardt said in an email.

The EPA does not recommend that contaminated households switch to bottled water, because the U.S. Food and Drug Administration has not established PFAS quality standards in bottled water, nor does it require testing for PFAS, although the International Bottled Water Association says its members test for the chemicals annually.

What are my filtration options?

Granular activated carbon systems, generally the least expensive treatment option, can remove some PFAS, including PFOA and PFOS. They work by binding PFAS to a porous carbon surface. But molecularly shorter chemicals, known as shortchain PFAS, may slip by. You can install the filter as a household unit or in sinks, faucets, refrigerators and pitchers.

Ion exchange resins act like little magnets that capture PFAS molecules. They are generally more effective than activated carbon, especially at snatching shortchain PFAS. Both technologies often cost less than reverse osmosis systems, which can run upwards of $1,000 to $2,000.

Reverse osmosis devices force highpressure water through a membrane with small pores to separate chemicals, including shortchain PFAS, from water. However, the technology requires a large volume of water, and it discharges PFAStainted backwash into sewer or septic systems — potentially reintroducing the contaminants into the environment.

“None of these techniques are perfect,” said Yanna Liang, a professor of environmental and sustainable engineering at State University of New York at Albany. “It really depends on what exact PFAS are in the water.”

If you can afford it, you can use multiple treatment systems in succession to increase effectiveness. That process is called a “treatment train.”

Reverse osmosis is the “gold standard” for high PFAS concentrations, but activated carbon filters work well for many who treat lower concentrations, said Riley Mulhern, an environmental engineer at RTI International.