Worried about "forever chemicals" in your drinking water?
Here's what you should know about "forever chemicals" and how they can be removed from your drinking water.
What are PFAS, where are they and why do we need to filter them out of the water?
PFAS, or per- and polyfluoroalkyl substances, are a family of man-made chemicals used for their water- and stain-resistant qualities in products like clothing and carpet, nonstick cookware, packaging and firefighting foam. The family includes 5,000 compounds, which are persistent, remaining both in the environment and human body over time.
The chemicals have been linked to types of kidney and testicular cancers, lower birth weights, harm to immune and reproductive systems, altered hormone regulation and altered thyroid hormones.
The chemicals enter the human body largely through drinking water, but removing them from water can prevent them from building up over time and potentially causing issues.
What types of filters are available to consumers?
Two types of water filtration systems work to remove PFAS from drinking water in your home: granulated activated carbon filters and reverse osmosis filters.
There are also different types of filters that can be installed, based on which water you want to filter.
Point-of-use filters can be installed underneath your sinks or come in pitcher variations and filter only the water being consumed. Whole house filtration systems filter all the water entering a home.
What are granulated activated carbon filters?
Granulated activated carbon filters run water through small pieces of carbon, which essentially act as a magnet for PFAS, pulling them from the water as it passes through, according to the state Department of Health Services.
Typically, pitcher filters, refrigerator and faucet-mounted filters and large whole-house treatment systems use this technology, but keep in mind that all filters are not certified to remove PFAS.
Typically, GAC filtration systems are the less costly option for point-of-use filtration.
In addition to removing PFAS, these systems can also remove other contaminants as well as some taste and odor compounds. The filters do not, however, remove nitrate, arsenic, manganese or microbes.
What are reverse osmosis filters?
In a reverse osmosis system, water is pushed through a filter membrane with small pores, according to the DHS. The membrane acts like a wall that stops PFAS and other chemicals from passing through.
Residential systems are typically set up on a kitchen countertop or in a cabinet below a kitchen sink.
RO systems require more frequent changes of filtration cartridges and membranes and use more water than other systems, which may increase your water bill. Depending on the quality of water coming into your home, you may need additional treatment devices as well, making the system more costly.
In addition to removing PFAS, these systems can remove nitrate and arsenic. They cannot remove bacteria and viruses, however.
How do I know if the filter I'm purchasing works on PFAS?
The best way to know if filtration systems work on PFAS is to check if they've been certified. The National Sanitation Foundation maintains a list of certified filters and the contaminants they are made to remove from water.
I already use a water filter pitcher. I'm safe, right?
Depending on your water pitcher, it may be able to filter out some of the common water pollutants, like heavy metals, but it may not be effective for removing PFAS. Fewer than 100 products are currently certified by the National Sanitation Foundation.
Brita and Berkey, two commonly asked about filtration systems, are not listed as being effective against PFAS.
ZeroWater pitchers are certified to remove the contaminants, according to the NSF listing.
What should I do with filters after they've been used?
For filtration systems that remove PFAS, keeping track of their lifespan is important. Don't use the filters for longer than recommended, because they can stop removing contaminants from the water.
Some granulated activated carbon filters can be regenerated, so make sure to check with the manufacturer for more information, said Dr. Sarah Yang, a toxicologist with the state Department of Health Services.
Other than that, make sure to follow the directions for disposal recommended by the manufacturer.
Typically, PFAS filtered out with activated carbon end up in landfills after disposal, while reverse osmosis systems typically concentrate PFAS in the untreated portion of the water leaving the system, reintroducing the contaminants to the environment outside the home.
What if I want to test my tap water on my own for PFAS?
If you live in a community where drinking water is already being tested, like Wausau, Yang said it's probably not necessary to retest your own water at home.
But if your community is not testing, there are labs that offer drinking water tests for purchase. Wisconsin has certified 13 labs that offer testing kits for purchase, but prices can range in the hundreds of dollars per test. For more information, visit dnr.wisconsin.gov.
If you choose to test your water, Yang said to make sure you take extreme caution in collecting samples, making sure that cross-contamination doesn't take place from other items in the house.
"There are PFAS in our houses in general, so be really careful when that sample is collected," she said. "PFAS can be in other areas of the home or even just in the dust."
After getting results back from the lab, homeowners are encouraged to share them with DHS staff, who can also help make sense of the data.
"The more information we have about where people are finding (PFAS), the more we can learn about the situation," she said.
Laura Schulte can be reached at email@example.com and on Twitter at @SchulteLaura.
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This article originally appeared on Milwaukee Journal Sentinel: What you should know about removing PFAS from your drinking water