PFOA and PFOS Information

Introduction to PFAS

Perfluoroalkyl substances (PFAS) are resistant to heat, water, and oil. Because of these characteristics, PFAS chemicals have a wide variety of industrial and commercial uses. Over time, researchers have studied the health effects of various PFAS chemicals, including PFOA, PFOS, PFBS, and GenX, with early research focusing primarily on PFOA and PFOS. Peer-reviewed studies of laboratory animals and epidemiological studies of human populations indicate that exposure to PFOA, PFOS, PFBS, and GenX over certain levels may result in adverse health effects.

Health advisories serve as technical guidance and provide information on contaminants that can cause human health effects and are known or anticipated to occur in drinking water. Health advisories are non-enforceable and non-regulatory. Health advisories take into account the other sources of exposure to PFAS, such as food and consumer products. 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, on May 25, 2016, EPA established lifetime health advisory levels at 70 parts per trillion for PFOA and PFOS in drinking water.

On June 15, 2022, EPA published lifetime health advisories for GenX of 10 parts per trillion and PFBS of 2,000 parts per trillion. EPA also updated the lifetime health advisories for PFOA and PFOS with interim health advisories. EPA updates health advisories as more information becomes available. This update reduced the lifetime health advisory for PFOA to 0.004 parts per trillion and the lifetime health advisory for PFOS to 0.02 parts per trillion. Analytical methods can detect PFOA and PFOS down to 4 parts per trillion, so the interim health advisories are significantly below detection. The EPA Science Advisory Board is still reviewing EPA’s analyses, so the interim health advisories may change in the future.

For more information about PFAS generally, please visit EPA’s PFAS website (Per- and Polyfluoroalkyl Substances (PFAS) | US EPA).

For more information about PFOA and PFOS, including EPD’s current drinking water monitoring initiative, and historical drinking water and surface water monitoring in Georgia, please visit the EPD PFAS StoryMap. If you are a drinking water system participating in EPD’s drinking water monitoring initiative, sample collection instructions and video are available.


      Current PFAS Issues

      In the winter of 2021, EPD initiated a targeted PFAS monitoring project to assess the level of PFAS in drinking water across Georgia. EPD started monitoring finished drinking water in the Coosa and neighboring Tennessee basins due to the documented presence of PFAS and PFAS sources in the Coosa basin. EPD sent sample kits to all surface water public drinking water systems and all groundwater public drinking water systems serving populations of 500 or more.

      This first round of monitoring identified no detectable GenX in finished drinking water. PFBS was found in 13 public water systems, all significantly below the health advisory. PFOA and PFOS were found in detectable levels in 10 public water systems. This data is available in the “Current and Future Monitoring” tab of the PFAS Story Map (PFOA and PFOS Information (

      Currently, EPD is sampling those large public water systems that serve populations of 100,000 or more. Those results will be posted to the PFAS StoryMap as they come in.

      What should a public water system do if PFAS chemicals are detected above their respective lifetime health advisories?

      EPD continues to recommend that public water systems initiate EPA’s three recommended actions in response to health advisory exceedances: assess PFAS levels, inform consumers, and limit exposure. Public water systems in Georgia used these three actions in response to previous PFAS health advisory exceedances, and EPD believes that these three actions remain effective. Overall, the lower the levels of PFOA and PFOS, the lower the risk, but there is no one-size-fits-all approach to get there. Public water systems are primarily responsible for determining the most appropriate response to a health advisory exceedance, and EPD remains available to provide technical assistance to public water systems with monitoring plans, technical communication, and identification of treatment options or alternative water sources.

      EPA plans to propose regulatory limits (maximum contaminant levels or MCLs) for PFOA and PFOS by the end of 2022 in accordance with EPA’s PFAS Strategic Plan (PFAS Strategic Roadmap: EPA's Commitments to Action 2021-2024 | US EPA). Public water systems with good, reliable monitoring data will be able to make informed decisions about treatment options and/or alternative water sources to meet the future regulatory limits. EPD recommends that public water systems without sufficient monitoring data develop and implement a monitoring plan to better assess PFAS levels. As public water systems evaluate their monitoring data and plan for the future, EPD is available to provide technical support.