Block 3




Block 4


PFAS are a class of thousands of different chemicals that have been manufactured and used in a variety of commercial products since the 1940s – from everyday household items to food packaging – due to its heat, moisture, and stain resistance and non-stick qualities. PFOA and PFOS have been the most extensively produced and studied of these chemicals, followed by PFHxS and PFNA. These chemicals do not break down in the environment or human body, and can accumulate over time. There is evidence that PFAS exposure can lead to adverse health effects.

ASDWA Resources


ASDWA PFAS – Source Water Protection Guide and Toolkit

ASDWA developed this guide and toolkit with support from a Project Advisory Council (PAC) with representatives from nine states (Colorado, Kansas, Minnesota, New Hampshire, North Carolina, Pennsylvania, Vermont, Virginia, and Wisconsin), and the Cadmus Group. The purpose of the guide is to demonstrate and share effective strategies for addressing PFAS contamination risk in source waters that will help inform policy decisions, assist state drinking water programs in protecting public health, and encourage collaboration and communication among states and water utilities.

The tool includes three main components and a factsheet:

The ASDWA PFAS SWP – Decision Support Tool is downloadable in Excel and provides examples of state actions to address PFAS contamination. It includes an update form for states and other organizations to submit updates or new entries for the Tool.

The factsheet for Communicating with Industry on PFAS Contamination includes best practices and questions with fillable fields to support state planning efforts.

The Technical Appendix includes an overview of PFAS, chemicals of concern, PFAS in the U.S., and state PFAS profiles.

The Mapping Guide aids identifying and mapping source waters that are vulnerable to PFAS contamination.

Download The Guide and Toolkit

Learn More About the Toolkit – in this webinar, ASDWA showcases the newly developed PFAS Source Water Protection Guide and Toolkit, sharing effective strategies for addressing PFAS contamination risk in source waters.

PFAS Background:  The understanding of potential drinking water impacts from PFAS has significantly increased over the past decade.  This class of chemicals started to get publicity in 2001 & 2002 due to water contamination from the Washington Works Plant located outside of Parkersburg, West Virginia, on the West Virginia/Ohio border.  The class-action lawsuit against DuPont due to water contamination at Little Hocking Water District and Lubeck Public Service District generated additional publicity.  In 2006, DuPont and other manufacturers such as 3M, agreed to principally phase out the production of PFOA and PFOS.

Third Unregulated Contaminant Monitoring Rule (UCMR3):  Due to escalating concerns, six PFAS compounds were included in EPA’s final UCMR3. UCMR3 monitoring occurred between January 2013 and December 2015 and included two to four quarterly samples at mostly large water systems throughout the country using EPA Method 537. As typical for the UCMRs, EPA regularly released the UCMR3 monitoring data, starting in late 2013.

EPA’s 2009 Provisional and 2016 Revised Health Advisories (HAs): In 2009, EPA established provisional health advisories (HAs) for PFOA at 400 parts per trillion (ppt) and for PFOS at 200 ppt; those two numbers were the benchmark at that time, even though an EPA health effects review was underway.  Based on the provisional health advisories, national occurrence in UCMR3 for PFOA and PFOS, at the time, appeared to be relatively low. In May 2016, EPA released revised HAs for the sum of PFOA and PFOS at 70 ppt. This numerical reduction significantly increased the number of water systems impacted.

UCMR3 Compound Name 2009 EPA HAs 2016 Revised HAs
PFOA Perfluorooctanoic acid 400 ppt 70 ppt (individual and combined sum with PFOS)
PFOS Perfluorooctanesulfonic acid 200 ppt 70 ppt (individual and combined sum with PFOA)
PFNA Perfluoroonanoic acid No HAs No HAs
PFHxS Perfluorohexanesulfonic acid
PFHpA Perfluoroheptanoic acid
PFBS Perfluorobutanesulfonic acid

2019 EPA PFAS Action Plan: Commitments by EPA in the action plan included:

  • Proposing a regulatory determination for PFOA and PFOS by the end of 2019.
  • Determining if a SDWA regulation is appropriate for a broader class of PFAS.
  • Including a larger group of PFAS in UCMR5.
  • Working through its regulatory development process for listing PFOA and PFOS as CERCLA hazardous substances.
  • Continuing to use its authority under TSCA to review new PFAS and issuing supplemental proposed Significant New Use Rules.
  • Finalizing the toxicity assessments for PFBS and GenX in 2019.
  • Developing draft toxicity assessments for PFBA, PFHxA, PFHxS, PFNA, and PFDA in 2020.
  • Developing guidance to facilitate cleanup of contaminated groundwater.
  • Developing new tools to characterize PFAS in the environment and materials to communicate about PFAS.

HAs Versus Regulatory Standards Create Challenges:  Use of HAs as guidance, versus a Safe Drinking Water Act (SDWA) regulation with an established Maximum Contaminant Level (MCL) creates challenges for state drinking water programs and public water systems. The HAs for PFOA and PFOS do not provide clarity on necessary actions for water systems to address the compounds, and how to communicate their actions and the associated health risks to the public.

State Regulatory and Oversight Challenges:  States are having to make tough decisions about whether or how to implement HAs and address PFAS in drinking water in the absence of federal standards. The table below shows the states that have proposed or established PFAS standards or guidelines that are lower or different than EPA’s HAs. These numbers demonstrate the variation in health risk goals and risk reductions among states in the absence of federal standards and are creating public confusion about what levels of PFAS are safe in drinking water.

State Drinking Water Action Compound Level (ppt)

Response Levels


Notification Levels










Connecticut Action Level Sum of PFOA, PFOS, PFNA, PFHxS, PFHpA 70
Massachusetts Adopted Regulation 9/16/20 Sum of PFOA, PFOS, PFNA, PFHxS, PFHpA, PFDA 20
Michigan Adopted Regulation 8/3/20
















Health Based Guidance for Water


Surrogate of PFOS HBV







New Hampshire Adopted Regulation 10/1/19









New Jersey

Adopted Regulation

Adopted Regulations 6/1/20







New York Adopted Regulation 7/30/20





North Carolina Health Advisory GenX 140
Vermont Adopted Regulation 3/17/20 Sum of PFOA, PFOS, PFNA, PFHxS, PFHpA 20

Click to expand the section below to see more examples of state efforts:

More PFAS Contamination Sites are Being Found:  The number of PFAS contaminated sites continues to grow. Over the past decade, PFAS contamination was found in many more locations beyond where the UCMR3 required water systems to conduct monitoring. Initially, contamination was thought to be somewhat limited to the chemical manufacturing facilities but has now expanded to include military bases, fire-fighting foam application, storage, and disposal sites, manufacturing sites of fire-retardant materials, landfills, and many other locations, including some that appear to be caused by air deposition. 

ASDWA PFAS Recommendations to EPA and CDC

ASDWA’s State Drinking Water Program Recommendations to EPA and CDC on PFAS (1/12/18) includes the following recommendations:

  • Form a working committee with ASDWA, EPA, CDC, and Department of Defense (DoD) leadership.
  • Develop a unified message and work with other stakeholders to minimize the potential adverse effects to public health and the environment.
  • Directly engage with states on any new federal actions and support current state efforts to consistently assess and address PFAS; and develop guidance for public water systems.
  • Conduct more health effects research and increase funding and support non-targeted analyses of drinking water for known and unknown PFAS, and substitute compounds.
  • Develop rules or guidance for other media (e.g., UIC, wastewater, soil leaching, air emissions).
  • Directly engage with stakeholders and industry to assess and address the universe of known and unknown PFAS compounds, and evaluate fire-fighting foam and alternatives.
  • Address laboratory and sampling needs for analytical methods and standards, lab vendors, standardization of lab results, and increase lab programs and capacity beyond UCMR3.

The Number of PFAS Being Manufactured Continues to Grow: The number of PFAS compounds that might be a cause of concern is thought to be in the hundreds and continues to grow. Since the phase-out of PFOA and PFOS, companies have shifted to “short-chain” PFAS such as GenX, which is now a significant concern in the Cape Fear Watershed downstream of a Chemours manufacturing plant in North Carolina. The increasing number of PFAS of concern is creating a host of data collection and analysis issues, as regulators and researchers are struggling to get enough robust health effects, analytical methods, and treatment data to make smart decisions.

For more information on how states are addressing PFAS, contact Deirdre White of ASDWA at


Download a PDF-version of this webpage.