EPA Limits PFAS in its New Drinking Water Rules

This week, the U.S. Environmental Protection Agency (EPA) finalized its National Primary Drinking Water Regulation (NPDWR) for per- and polyfluoroalkyl substances (PFAS) to limit the legal concentration of both several individual PFAS and total PFAS compounds in drinking water nationwide, using its authority under the federal Safe Drinking Water Act.

PFAS, or “forever chemicals,” are a class of long-lasting chemical compounds that accumulate in the environment and in many living organisms over time.  PFAS have been linked to adverse health conditions, including increased cholesterol, changes in liver enzymes, immune system deficiencies, decreases in birth weight, and kidney and testicular cancer.  While manufacturers stopped using many of the most harmful PFAS compounds years ago, thousands of PFAS are still used in a wide variety of products ranging from aqueous fire-fighting foams and ski waxes to fast-food packaging due to their water resistance, stain resistance, thermal regulation, and surfactant properties. 

EPA set maximum contaminant level standards (MCLs) for perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHxS), and GenX chemicals in parts per trillion (ppt). 

The final NPDWR also limits mixtures of two or more of PFNA, PFHxS, GenX chemicals, or PFBS according to a hazard index based on known or anticipated adverse health impacts. 

EPA estimates the final NPDWR will:

• • Reduce PFAS exposure for 100 million Americans and
  • Prevent tens of thousands of PFAS-related cases of cancers, liver and heart impacts in adults, as well as immune and developmental impacts to infants and children.

This final rule will impact public drinking water systems nationwide, which will be required to:

• • Monitor their drinking water for PFAS contaminants
  • Inform the public of their results and
  • Implement solutions to reduce PFAS concentrations in their drinking water below the NPDWR standards within the next five years.

Water systems that exceed the NPDWR standards will have to switch to uncontaminated source waters or install treatment such as granular activated carbon, ion-exchange, and reverse osmosis systems to reduce PFAS concentrations. Most standard municipal water utilities do not currently treat or filter drinking water to remove PFAS compounds, and many are not currently even equipped to detect PFAS at levels in the parts per trillion.

EPA estimates the total cost for public water systems to comply with the new NPDWR will be approximately $1.5 billion per year. According to the EPA, more than $20 billion in funding under the Bipartisan Infrastructure Law has been made available to communities to make general drinking water improvements, including PFAS monitoring and treatment technologies.

Legal challenges to the final rule are anticipated from manufacturers, industry groups, and water utilities themselves. Some commenters have argued that EPA failed to adequately demonstrate the need for the rule and significantly underestimated the costs of compliance with the rule.  Such challenges may delay implementation of the new rule, require EPA to shore up its rationale for the rule, or, if successful, force EPA back to the drawing board altogether.

In March 2023, EPA had proposed national standards for PFOA and PFOS. At that time, the agency also announced preliminary regulatory determinations for PFHxS, PFNA, GenX chemicals and PFBS. EPA considered more than 120,000 public comments on its draft rule before issuing its final rule.

Please contact Sophie Gray or any member of the Phelps Environmental team if you have questions or need advice or guidance.