Board prioritizes PFAS, disinfection byproducts, metals and on-site reuse rules; adopts item 3 resolution

The State Water Resources Control Board on Feb. 19 reviewed the Division of Drinking Water’s proposed regulatory priorities for the coming year and adopted a resolution formalizing those priorities by roll-call vote.

Division staff told the board PFAS regulation — both an initial phase to adopt federal requirements for primacy and a second, more California‑specific phase possibly relying on treatment‑technique approaches — is the single top priority for the division in 2025.

“PFAS is our top priority and primary focus for this year,” said the division presenter (Division of Drinking Water staff). Staff described a two‑stage approach: stage 1 to mirror federal requirements and attain primacy for the federal PFAS rule, and stage 2 to consider California‑specific approaches such as use of sentinel indicator compounds or treatment‑technique requirements where numeric MCLs are impractical for large PFAS subclasses.

Staff also outlined planned work on a range of other priorities: disinfection byproducts (including total trihalomethanes and haloacetic acids), arsenic, NDMA (a nitrosamine disinfection byproduct), styrene, cadmium and mercury MCL revisions, revisions to detection…