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.

On March 14, 2023, EPA announced the proposed National Primary Drinking Water Regulation (NPDWR) for six PFAS including PFOA, PFOS, PFBS, GenX, as well as perfluorononanoic acid (PFNA) and perfluorohexane sulfonic acid (PFHxS).  The proposed PFAS NPDWR does not require any actions until it is finalized, and EPA is requesting public comment on the proposed regulation following its publication in the federal register.  EPA anticipates finalizing the regulation by the end of 2023.  The proposed NPDWR includes draft Maximum Contaminant Levels (MCLs) of 4.0 parts per trillion for PFOA, 4.0 parts per trillion for PFOS, and a unitless Hazard Index level for the other 4 PFAS (PFBX, GenX, PFNA and PFHxS).  More details on the proposed NPDWR can be found at EPA’s website,

For more information about PFAS generally, please visit EPA’s PFAS website.

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.

      Following the completion of the first phase of monitoring, EPD conducted a second round of monitoring of finished drinking water, which focused on large public water systems that serve populations of 100,000 or more, as well as those systems located in close proximity to significant Department of Defense installations. As with the first round of monitoring, this data is available in the “Current and Future Monitoring” tab of the PFAS Story Map.

      In 2023, EPA initiated monitoring under UCMR 5. This monitoring includes 29 species of PFAS, and all public water systems serving populations of 3,300 or more are required to participate. To complement this effort, EPD will initiate a third and final round of monitoring in finished drinking water. This third round of monitoring will focus on public water systems not included in UCMR 5. Specifically, EPD will conduct monitoring of finished drinking water from very small public water systems that rely on groundwater in areas where Download this pdf file. groundwater is highly susceptible to pollution . Those results are posted to the PFAS StoryMap as this round of monitoring progresses.

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

      EPD continues to encourage public water systems to 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 have used these three actions in response to previous PFAS health advisory exceedances, and these three actions remain effective. Overall, the lower the levels of PFAS, the lower the risk, but there is no one-size-fits-all approach to reduce exposure. Public water systems are primarily responsible for determining the most appropriate response to a health advisory exceedance, and EPD is available to provide technical assistance to public water systems with technical communication, review of proposed monitoring plans, and identification of treatment options and/or alternative water sources.

      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 that EPA plans to finalize by the end of 2023. EPD recommends that public water systems without sufficient monitoring data develop and implement a monitoring plan to better assess their PFAS levels. As public water systems evaluate their monitoring data and plan for the future, EPD is available to provide technical support.