Once UCMR 5 goes into effect in 2023, ALL public water systems serving more than 3300 people plus 800 randomly selected smaller water systems will need to begin testing for 29 PFAS (and Lithium). That is, if EPA leaves its current UCMR 5 proposal unchanged before it finalizes the rule. It’s also likely that, before UCMR 5 sampling starts in 2023, PFOA and PFOS will have federally enforceable MCLs (Maximum Contaminant Limits) for all water systems under the SDWA (Safe Drinking Water Act).
