December 9, 2016
EPA Issues Drinking Water Health Advisories for PFOA and PFOS
POSTED BYWilliam Shane, P.E.
In May 2016, EPA released drinking water health advisories for Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS). For many years, these chemicals were widely used in carpets, clothing, fabrics in furniture, food packaging, and other materials (e.g., cookware) to make them more resistant to water, grease, and stains. They are also used for firefighting at airfields and in a number of industrial processes. According to the EPA, exposure to PFOA and PFOS over certain levels may result in adverse health effects, such as developmental effects to fetuses, cancer, liver effects, and immune effects. Between 2000 and 2002, PFOS was voluntarily phased out of production in the U.S. by its primary manufacturer. EPA also asked eight major companies to eliminate their production and use of PFOA by the end of 2015. These companies indicated that they have met their commitments.
The health advisories for these two chemicals were issued under the authority of the Safe Drinking Water Act, but are non-regulatory. Therefore, the National Primary Drinking Water Regulations (NPDWR) do not list PFOA or PFOS as contaminants and do not include an associated Maximum Contaminant Level Goal (MCLG) or Maximum Contaminant Level (MCL). The advisories are based on peer-reviewed toxicological studies of animal exposure and epidemiological studies of human populations that have been exposed to these chemicals. After review of the available research, EPA established the health advisory levels at 70 parts per trillion. When both PFOA and PFOS are found in drinking water, the combined concentrations of PFOA and PFOS should be compared with the 70 parts per trillion health advisory level.
On EPA Connect, the official blog of the EPA Leadership, the Deputy Assistant Administrator for the Office of Water wrote that “if these chemicals are found in drinking water systems above these levels, system operators should quickly conduct additional sampling to assess the level, scope, and source of contamination. They should also promptly notify consumers and consult with their state drinking water agency to discuss appropriate next steps.” The Water Research Foundation (WRF) investigated available treatment technologies to determine what next steps a drinking water utility might consider. The WRF found that aeration, chlorine dioxide, dissolved air flotation, coagulation, flocculation, sedimentation, granular filtration and microfiltration were all ineffective at removing PFOA and PFOS contamination. The investigation found that, for most drinking water utilities, granular activated carbon (GAC) was the most cost-effective treatment technology.
William Shane is an Environmental Engineer at Smith Management Group. William can be reached at firstname.lastname@example.org.