The U.S. Environmental Protection Agency (USEPA) released the first set of data collected under the fifth Unregulated Contaminant Monitoring Rule (UCMR 5). The new data is the initial step towards improving USEPA’s understanding of the levels and frequency that 29 PFAS and lithium are found in the nation’s drinking water systems. The initial monitoring represents sampling from more than 2,000 public water systems. USEPA aims to use the data to develop future actions to protect public health under the Safe Drinking Water Act. It will also help USEPA better understand the nation’s level of exposure to the 30 unregulated chemicals.
The initial data release represents approximately 7% of the total results USEPA expects to receive over the next three years. Eleven more data sets will be released quarterly in the National Contaminant Occurrence Database (NCOD) until the completion of USEPA’s reporting in 2026.
In March, USEPA proposed a National Primary Drinking Water Regulation (NPDWR) for six PFAS to establish legally enforceable levels, called Maximum Contaminant Levels (MCLs), as well as health-based, non-enforceable Maximum Contaminant Level Goals (MCLGs). The six PFAS include perfluorobutane sulfonic acid (PFBS), perfluorohexanesulfonic acid (PFHxS), perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), and hexafluoropropylene oxide dimer acid (HFPO-DA), which are commonly known as GenX Chemicals. The proposed MCLs and MCLGs are listed in the table below:
| Compound | Proposed Maximum Contaminant Level Goals (Non-enforceable) | Proposed Maximum Contaminant Levels (Enforceable) |
| PFOA | Zero | 4.0 parts per trillion (also expressed as ng/L) |
| PFOS | Zero | 4.0 ppt |
| PFNA | 1.0 (unitless) Hazard Index | 1.0 (unitless) Hazard Index |
| PFHxS | ||
| PFBS | ||
| HFPO-DA / GenX Chemicals |
The proposed NPDWR for PFAS would also require public water systems to:
- Monitor for the six PFAS
- Notify the public of detected levels
- Reduce the levels in drinking water if they exceed the proposed standards
USEPA is expected to finalize the NPDWR for PFAS by the end of 2023. In the interim period before the PFAS drinking water standard is final, USEPA has established Health Advisories for four PFAS included in the UCMR 5.
Meanwhile, there is an unprecedented $9 billion of funding included in the Bipartisan Infrastructure Law to invest in communities with drinking water impacted by PFAS and other emerging contaminants. This includes $4 billion via the Drinking Water State Revolving Fund (DWSRF) and $5 billion through USEPA’s “Emerging Contaminants in Small or Disadvantaged Communities” grant program. States, Tribes and communities can further leverage an additional nearly $12 billion in BIL DWSRF funds and billions more in annual SRF funds dedicated to making drinking water safer. These funds will help communities make important investments in solutions to remove PFAS from drinking water.
AE2S is monitoring regulatory developments related to PFAS. There is a new webpage focused on PFAS in the Perspectives and Insights section of AE2S.com. Contact Nate Weisenburger, AE2S Drinking Water Practice Leader for additional PFAS information as it relates to your water system.
For access to additional information about the USEPA’s UCMR 5 monitoring and data, visit the USEPA website.