On April 10, 2024, EPA announced the final National Primary Drinking Water Regulation (NPDWR) for six PFAS in drinking water. The new rule set enforceable Maximum Contaminant Levels (MCLs) of 4.0 parts per trillion (ppt) individually for PFOA and PFOS, 10 ppt for PFHxS, PFNA, and HFPO-DA (commonly known as GenX Chemicals) as well as a Hazard Index of 1 for mixtures of two or more PFAS including PFHxS, PFNA, HFPO-DA and PFBS. Public water systems with PFAS levels above the MCLs are required to take action over the next five years to comply with the new standards to provide safe and reliable drinking water to their communities.
EPA also finalized non-enforceable, health-based Maximum Contaminant Level Goals (MCLGs) for these PFAS. The MCLGs are set at zero (0 ppt) for PFOA and PFOS. The MCLGs for PFHxS, PFNA, HFPO-DA and the Hazard Index match their MCLs. MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration. The MCLs, which are used for compliance determination, are set at specific concentrations that laboratories nationwide can measure with high certainty.
Compound
| Maximum Contaminant Level Goal (MCLG)
|
Maximum Contaminant Level (MCL) (enforceable levels)
|
PFOA
| 0
| 4.0 ppt (parts per trillion)
|
PFOS
| 0
| 4.0 ppt
|
PFHxS
| 10 ppt
| 10 ppt
|
PFNA
| 10 ppt
| 10 ppt
|
HFPO-DA (commonly known as GenX Chemicals)
| 10 ppt
| 10 ppt
|
Mixture of two or more: PFHxS, PFNA, HFPO-DA and PFBS
| Hazard Index of 1 (unitless)
| Hazard Index of 1 (unitless)
|
To learn more about the final PFAS NPDWR, visit EPA’s
webpage.
For more information on how drinking water systems will comply with the new regulations, please visit the Division of Water’s
Drinking Water Compliance page.
The Department for Environmental Protection (DEP) began sampling public drinking water for PFAS in 2019 and has continued to collect additional data at public drinking water treatment plants statewide. Results were shared with water systems and are available on this page to provide information on the presence of PFAS across the state. With the release of the proposed regulations in March 2023, DEP staff engaged with systems to spread awareness of the pending regulations, their potential impacts, and treatment options. Based on currently available data, less than 10% of community drinking water treatment plants have had a result above the newly established MCLs. As additional data is gathered, very few water treatment plants repeatedly exceed the MCLs. The DEP will continue to sample and provide assistance to public water systems as they address the challenges of PFAS contamination in drinking water for the protection of public health in the Commonwealth.
In 2019, department staff sampled finished drinking water from 81 community public drinking water treatment plants (WTP). WTPs were selected to represent surface and groundwater sources, urban and rural land-use influence, and varying sizes of populations served. One or more PFAS were detected in 41 of the 81 WTPs. Click the link below to read the full report.
In 2023, staff sampled finished drinking water from an additional 113 water treatment plants not included in the 2019 study. Results from that study are available at the links below.