EPA Posts First Release of UCMR5 Occurrence Data

The Environmental Protection Agency (EPA) posted the first release of results from the Unregulated Contaminant Monitoring Rule 5 (UCMR5). A copy of EPA’s summary of the results is here (ucmr5-data-summary_July 2023 ) Table 3 presents the summary of results to date.

Files with the individual results have also been posted on EPA’s web site at the following location:

Background: The final UCMR5 was published on December 27, 2021. Under the UCMR5, monitoring for 29 per- and polyfluoroalkyl substances (PFAS) and lithium will occur during 2023-2025. Monitoring will be as follows: one year of quarterly monitoring for surface water systems, and two samples (5 to 7 months apart) in a 12 month period for groundwater systems. Required participation in UCMR monitoring is based on population served.