Every five years, the Safe Drinking Water Act (SDWA) requires EPA to issue a list of priority unregulated contaminants to be monitored by certain public water systems serving between 3,300 and 10,000 people across States, Tribes, and Territories. These contaminants may be present in drinking water but are not yet subject to EPA drinking water standards. Under the Unregulated Contaminant Monitoring Rule (UCMR), EPA collects nationally representative drinking water occurrence data to support EPA’s future regulatory determinations and assist in the development of national primary drinking water regulations (NPDWRs) as needed. For each UCMR cycle, EPA establishes a new list of contaminants for monitoring, specifies which systems are required to monitor, identifies the sampling locations, and defines the analytical methods to be used.
In December of 2021, the EPA published a revision of the Unregulated Contaminant Monitoring Rule (UCMR 5) for Public Water Systems. This monitoring cycle includes preparations in 2022, sample collection from 2023 – 2025, and completion of data reporting in 2026.
Which water systems will participate in UCMR 5?
- This requirement is based on the availability of appropriations and sufficient laboratory capacity
- Community Water Systems (CWSs), Non-Transient Non-Community Water Systems (NTNCWSs)
- Counts are approximate
What resources can help optimize UCMR 5 analysis workflow?
Regulatory entities have developed methods specifically for the determination of PFAS. These workflows use different sample preparation methods, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) technologies to detect low concentrations of PFAS compounds in the low ng/L range. However, due to its complexity, laboratories continue face challenges in obtaining comprehensive quality data when conducting PFAS analyses.
One of the challenges of PFAS analysis occurs at calibration. Certified Reference Materials in a salt form at different concentrations require time-consuming error-prone calculations resulting in calibration errors.
Phenomenex has recently launched Phenova CRMs that contain all the mix’s analytes in acid form and at the same concentration for easy calculation and dilution. Laboratories using Phenova PFAS CRM reported 50% or higher in time savings during PFAS calibration preparation. You can find out more about CRMs and other PFAS workflow tools at www.phenomenex.com/pfas
What PFAS compounds need to be reported for UCMR 5?
UCMR 5 specifies monitoring for 29 per- and polyfluoroalkyl substances (PFAS). Below is the complete list according to the EPA UCMR 5 Fact Sheet.
- CASRN – Chemical Abstracts Service Registry Number
- MRL – Minimum Reporting Level
What is UCMR 5 sampling frequency and timing?
Water systems will be required to collect samples based on the typical UCMR sampling frequency and timeframe.
More PFAS Resources
- UCMR Website for information on current and past UCMRs, occurrence data, and public meetings
- EPA Ground Water and Drinking Water Website for information on source water protection, drinking water regulations, monitoring requirements for States and systems, SDWA on Tribal lands, and laboratory certification
- EPA PFAS Website for information on the Agency’s actions to address PFAS