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California Lowers PFAS Drinking Water Notification Levels and Starts Regulatory Process

The California State Water Resources Control Board (SWRCB) has updated its guidelines for drinking water notification levels (NLs) and has begun the process of establishing regulatory standards for PFOA and PFOS. The updated guidelines lower the current NLs from 14 parts per trillion (ppt) to 5.1 ppt for PFOA and from 13 ppt to 6.5 ppt for PFOS. The new NLs are based on updated health recommendations by the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) and are part of a comprehensive statewide assessment on the scope of PFOA and PFOS contamination in drinking water supplies.

California has different notification and response levels for PFOA and PFOS that are both nonregulatory, precautionary health-based measures. While the statewide assessment continues, the response levels for PFOA and PFOS will remain at 70 ppt for the total combined concentration of both contaminants, consistent with the EPA’s health advisory level. Response levels are set higher than notification levels and represent a recommended level for water systems to consider either taking a water source out of service or providing treatment if that option is available to them. A new California law will take effect on January 1, 2020 that will turn these actions into mandatory requirements using new response levels – to be updated this fall.

For reference, the OEHHA health recommendations are based on the development of PFOA and PFOS reference levels (RLs) for cancer effects. The RLs developed for not posing more than a one in one million cancer risk over a lifetime are 0.1 ppt for PFOA and 0.4 ppt for PFOS. The RLs developed for noncancer are 2 ppt for PFOA and 7 ppt for PFOS. However, because the cancer RLs are so low, the drinking water notification levels were instead set at the lowest levels at which PFOA and PFOS can be reliably detected using currently available technologies.

For more information, view the California SWRCB media release and web page.