EPA Announces the Release of Eighth Set of Data Under UCMR5
On Monday, June 2, US EPA released the eighth set of national drinking water data collected under the fifth Unregulated Contaminant Monitoring Rule (UCMR 5) for 30 chemical contaminants: 29 PFAS and lithium. SDWA requires that, every five years, EPA issue a list of unregulated contaminants to be monitored by public water systems. UCMR 5 was published on December 27, 2021, with large, medium, and a nationally representative sample of small public water systems collecting data on these 30 chemical contaminants since January 1, 2023.
The data released to date represents approximately 75% of the total results EPA expects to receive by completion of data reporting in 2026. The eighth data release includes approximately 1.5 million sample results for 8,800 public water systems.
UCMR 5 eighth data release includes updates to:
- UCMR 5 Data Finder – Allows the public, along with federal, state, and local agencies, to easily locate, view, and summarize specific UCMR 5 results, as well as download those results to an Excel (.xlsx) spreadsheet. Results can be filtered by multiple fields. A video demo is available. Please use (and encourage others to use) this tool for accessing the publicly available results.
- Occurrence Data Text Files – Recommended for those interested in large-scale data processing using statistical or data analysis software. These files contain analytical results and the additional data element and ZIP Code information reported by participating public water systems.
- UCMR 5 Data Summary – National summary statistics by contaminant, health effects information, data considerations, and data definitions for the UCMR 5 Data Finder and Occurrence Data Text Files.
- UCMR 5 Website Q&A – Answers to common questions on accessing and understanding the UCMR 5 data, and on PFAS and lithium in drinking water.
