The U.S. Environmental Protection Agency (USEPA) published its ninth set of national drinking water data collected under the fifth Unregulated Contaminant Monitoring Rule (UCMR 5).
The UCMR 5 requires sample collection for 30 chemical contaminants between 2023 and 2025. The data collected helps measure the amount of 29 per- and polyfluoroalkyl substances (PFAS) and lithium in the nation’s drinking water.
To date, USEPA says the following percentage of each size of public water system (PWS) reported a full set of UCMR 5 results for at least one location:
- 8.0% of small PWS serving fewer than 3,300 people
- 8.4% of medium PWS serving 3,300 -10,000 people
- 15.0% of large PWS serving 10,000+ people
USEPA uses the UCMR to collect data for contaminants that are suspected of being present in drinking water and do not have regulatory standards set under the Safe Drinking Water Act (SDWA). The SDWA requires USEPA to issue a list of unregulated contaminants once every five years to be monitored by public water systems. The monitoring provides nationally representative data on the occurrence of contaminants in drinking water, the number of people potentially being exposed, and an estimate of the levels of that exposure. The data can be utilized to make regulatory determinations to protect public health.
Updates included in the UCMR 5 data release include:
- UCMR 5 Data Finder – UCMR 5 results can be easily located, viewed, and summarized as well as downloaded.
- Occurrence Data Text Files –The 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 Q&A – Answers to common questions on accessing and understanding the UCMR 5 data, and on PFAS and lithium in drinking water.
Reach out to Nate Weisenburger, AE2S Drinking Water Practice Leader, if you have questions about the UCMR 5.