29 PFAS Compounds Being Monitored in Public Water Systems Under UCMR 5

Every five years, the United States Environmental Protection Agency (US EPA) issues a new list of unregulated chemicals to be monitored by public water systems under the Safe Drinking Water Act (SDWA). The US EPA published the fifth Unregulated Contaminant Monitoring Rule (UCMR 5) in December 2021. UCMR 5 includes 29 per- and polyfluoroalkyl substances (PFAS), as well as lithium, to be monitored by public water systems from 2023 through 2025.¹ This monitoring period will give the US EPA insight into the occurrence and concentration levels of these 30 contaminants in drinking water systems. Based on these findings, the US EPA can begin the process of implementing future regulations as well as other necessary actions to protect public health.

CIL offers EPA Method 533 and 537.1 standard mixtures to support UCMR 5 testing, as well as a unique supplemental mixture of native N-MeFOSAA, N-EtFOSAA, PFTeA, and PFTrA, which are included in Method 537.1, but not Method 533. This supplemental mixture was developed to augment the native Method 533 mixture to allow for testing of all native PFAS analytes targeted in UCMR 5.