PFOA and PFOS Information

What are PFOA and PFOS?

  • PFOA and PFOS are part of a larger group of chemicals referred to as perfluoroalkyl substances (PFASs) that are resistant to heat, water and oil.  PFOA and PFOS have been the most extensively produced and studied of these chemicals.  PFASs, including PFOA and PFOS, have been used to make carpets, clothing, fabrics for furniture, paper packaging for food and other materials, such as cookware, that are resistant to water, grease or stains.  They are also used for firefighting at airfields and in several industrial processes. Because these chemicals have been used in many consumer products, most people have been exposed to them.
  • For more basic information about PFAS, please visit EPA’s PFAS webpage:

What are the health effects of PFOA and PFOS?

  • Peer-reviewed studies of laboratory animals and epidemiological studies of human populations indicate that exposure to PFOA and PFOS over certain levels may result in adverse health effects, including developmental effects to fetuses during pregnancy or to breastfed infants, cancer, changes to liver and thyroid function, immune effects, and increases in cholesterol levels.
  • For more information about the health effects of PFOA and PFOS, please visit the Center for Disease Control’s Agency for the Toxic Substances and Disease Registry PFAS webpage:

What is EPA’s Health Advisory Level?

  • Health advisories provide information on contaminants that can cause human health effects and are known or anticipated to occur in drinking water. To provide Americans, including the most sensitive populations, with a margin of protection from a lifetime of exposure to PFOA and PFOS from drinking water, EPA established health advisory levels at 70 parts per trillion. When both PFOA and PFOS are found in drinking water, the combined levels of PFOA and PFOS should be compared with the 70 parts per trillion health advisory level.
  • For more information about EPA’s Health Advisory Level for drinking water, please visit EPA’s Drinking Water Health Advisories for PFOA and PFOS webpage:

Current PFOA and PFOS Issues

City of Summerville

  • EPA and EPD conducted joint sampling of the City of Summerville’s drinking water sources and finished drinking water on January 23, 2020. On January 30, 2020 sample results came back showing combined levels of PFOA and PFOS in the finished drinking water from the Raccoon Creek Treatment Plant of 98 parts per trillion, which is above EPA’s health advisory level.  In addition, combined levels of PFOA and PFOS in the Goodwin Hill Tank were found to be 92 parts per trillion.
  • In light of the EPA health advisory, the City of Summerville has taken steps to notify its customers and identify alternative water sources. For more information about the City of Summerville’s response, please visit the City’s webpage:
  • Download this pdf file.EPA Sampling Report for Summerville