Sparks (775) 355-0202 | Elko (775) 777-9933 | Las Vegas (702) 475-8899
Sparks (775) 355-0202
Elko (775) 777-9933
Las Vegas (702) 475-8899
Western Environmental
Testing Laboratory
Lessons From the Lab


Learn more about some regulatory changes below!

The Safe Drinking Water Act (SDWA) requires that once every five years EPA issues a list of unregulated contaminants to be monitored by public water systems (PWSs).

The fifth Unregulated Contaminant Monitoring Rule (UCMR 5) was published on December 27, 2021. UCMR 5 requires sample collection for 30 chemical contaminants between 2023 and 2025 using analytical methods developed by EPA and consensus organizations (https://www.epa.gov/dwucmr/fifth-unregulated-contaminant-monitoring-rule). This action provides EPA and other interested parties with scientifically valid data on the national occurrence of these contaminants in drinking water. Consistent with EPA’s PFAS Strategic Roadmap, UCMR 5 will provide new data that is critically needed to improve EPA’s understanding of the frequency that 29 PFAS (and lithium) are found in the nation’s drinking water systems and at what levels. This data will ensure science-based decision-making and help prioritize protection of disadvantaged communities.

If you have any questions, or want to learn more about this change, please contact Nick at NickR@wetlaboratory.com.


Additionally, California is proposing lower limit for manganese in drinking water.

The State Water Board’s Division of Drinking Water (DDW) is proposing a notification level of 20 parts per billion (ppb) or micrograms per liter (mg/l) and a response level of 200 mg/l for manganese. These levels are based on adverse neurotoxicological effects seen in laboratory animals exposed to manganese. DDW derived a health protective concentration (HPC) using several resources; the HPC is based on one specific candidate study.

The current manganese notification and response levels are 0.5 parts per million (ppm) or milligrams per liter (mg/l) and 5.0 mg/l, respectively.

An informational item on the proposed manganese notification and response levels is planned for the State Water Board’s March 21, 2023 meeting.

The proposed notification and response levels and links to the studies are available at the Division’s website at https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/NotificationLevels.html.

If you have further questions, please contact Andy at andys@wetlaboratory.com.