Water suppliers including EBMUD were required to sample PFAS from 2013 to 2015 to meet federal EPA requirements (Unregulated Contaminant Monitoring Rule 3). None were detected in EBMUD water under this monitoring effort.
In 2016 the EPA established a drinking water health advisory of 70 parts per trillion (ppt) for a combined concentration of PFOA and PFOS (A part per trillion is the equivalent of one grain of sand in an Olympic-size swimming pool).
In 2019, California developed "notification levels" for two particular PFAS. PFOS has a notification of 6.5 ppt, and PFOA’s is 5.1 ppt. Exceeding the notification level would require notification of the State Board. In 2020, California adopted a "response level" of 10 ppt for PFOA and 40 ppt for PFOS. Exceeding the response level would require that the source be taken out of service or that formal, written public notification be made.
About half of all states and the EPA are beginning to regulate PFAS (individually and as a group). Some states have mandatory levels, others have various types of advisories.
AB 756 (effective Jan 1, 2020): authorizes the State Water Resources Control Board Division of Drinking Water to require PFAS sampling, but DDW has not indicated low-risk systems like EBMUD’s will be part of early efforts. High-risk systems, vulnerable to PFAS contamination, have already begun monitoring under orders from the State Division of Drinking Water. Results are posted on DDW’s website.