In the years since the lead crisis in Flint, Michigan, increased attention has been paid to drinking water contamination problems across the country. This is, the focus is increasingly on pollution from a group of chemicals call per- and polyfluoroalkyl substances or PFAS for short.
These chemicals were widely used for decades in commercial and consumer products and are better known by their brand names, such as Teflon, Scotchgard and GORE-TEX. Because of their widespread use and ability to move through the water, soil and air, they can also be found in over 95 percent of people in the United States. The potential health effects of exposure to PFAS are not well understood. PFAS chemicals have been linked to cancers and other health issues in animal laboratory studies.
The EPA, through the Safe Drinking Water Act, requires public water systems to test for a list of PFAS chemicals. The agency, however, has yet to establish an enforceable regulatory limit that would require action by public water supplies if exceeded.
In May 2016, the agency issued a health advisory limit for some PFAS compounds of 70 parts per trillion (ppt). Health advisories describe non-regulatory concentrations of drinking water contaminants at or below which adverse health effects are not anticipated to occur. Unfortunately, health advisories do not provide clear guidance to public water systems on what actions should be taken to address the contamination.
In the absence of enforceable federal standards, a few states have established lower thresholds for the chemical in drinking water supplies. New Jersey, for instance, has adopted a drinking water contamination level of 14 ppt. Vermont established a limit of 20 ppt.
The number of PFAS contaminated sites continues to grow. Northwestern University and the Environmental Working Group recently released an interactive map of contaminated sites and communities where PFAS has been detected in drinking water. Several of these sites are in coastal Mississippi and Alabama, primarily due to the presence of military bases where PFAS-containing fire-fighting foam and other products may have been used extensively.