After decades of delay, the Environmental Protection Agency established legally-enforceable levels of six PFAS commonly found in drinking water. The legislation is considered a key step toward wider consumer protection related to PFAS.

What Is The National Primary Drinking Water Regulation?

The National Primary Drinking Water Regulation (NPDWR) expands on several state-led efforts to establish safe levels of PFAS in drinking water. The federal effort collates the work of several state programs to create a nationwide level for these six key PFAS.

The six types of PFAS included in the regulations are:

  • perfluorooctanoic acid (PFOA)
  • perfluorooctane sulfonic acid (PFOS)
  • perfluorononanoic acid (PFNA)
  • hexafluoropropylene oxide dimer acid (HFPO-DA, commonly known as GenX Chemicals)
  • perfluorohexane sulfonic acid (PFHxS)
  • perfluorobutane sulfonic acid (PFBS)
Compound Proposed MCLG Proposed MCL (enforceable levels)
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

HFPO-DA (commonly referred to as GenX Chemicals)


What It Means

The regulation isn’t enforceable and may not be fully implemented until the end of 2023. The EPA allows for public comment and review (information on that below) which could see limits on each PFAS shift. The proposed regulation is an encouraging sign, however, that the EPA is committed to protecting American families from polluted drinking water.

The regulations would also require all public water systems to proactively monitor, alert and address elevated levels of PFAS. This would increase awareness in the general public for the presence of these six types of PFAS and the dozens of similar PFAS that tend to co-occur.

WATCH: Less Cancer Board Member Rob Bilott discusses the NPDWR on MSNBC.

How We Finally Got PFAS Drinking Water Standards

The roots of the NPDWR are in the Safe Drinking Water Act. The SDWA was substantially strengthened by several amendments in 1996, which allowed the EPA to include more than 90 contaminants and provide expanded regulatory guidance to public water works across the country. The SDWA has championed improved standards within the FDA and leveraged public input, its Science Advisory Board, and state and local governments to advance the NPDWR.

How You Can Get Involved

The EPA’s public comment period begins once the regulation is published in the Federal Register. You can submit your thoughts and support strict PFAS regulations.

Keep the momentum going! Make a commitment to cancer prevention by joining the Less Cancer Hike and Bike America. The monthly-long activity challenge is our biggest fundraiser of the year, challenging individuals and families to get active June 2 – July 2. Register today and share with your friends!