News & Events

Staying Ahead of PFAS

The EPA’s New Health Advisory Levels and the Northeast State Regulations You Need to Know

By Darline Tenney and Derek Belanger, PE

Per- and Polyfluoroalkyl Substances (PFAS) are a group of man-made compounds that have extensive industrial and consumer product applications, including firefighting foams, non-stick surfaces, and surfactants.  They are persistent in the environment and are water-soluble, which has resulted in them finding their way into ground and surface waters across the country. PFAS has been an evolving issue in the Northeast for years, with many states taking a leadership role in developing guidance for regulations.


In 2012, the United States Environmental Protection Agency (EPA) included PFAS compounds in its Third Unregulated Contaminant Monitoring Rule (UCMR3) which required the monitoring of six individual PFAS compounds. During UCMR3 testing, Health Advisories (HAs) set by the EPA were 400 parts per trillion (ppt) for Perfluorooctanoic acid (PFOA) and 200 ppt for Perfluorooctane-sulfonate (PFOS).  In May 2016, following the UCMR3 testing, EPA lowered the HAs to 70 ppt for PFOA and PFOS (either individually or combined). This was based on the agency’s assessment of the latest peer-reviewed science at the time.

More recent studies have indicated that PFOA and PFOS can impact human health at levels much lower than the 2016 HAs. As a result, in June 2022, the EPA published an Interim Health Advisory to replace the 2016 HA. The new HAs were set to 0.004 ppt and 0.02 ppt for PFOA and PFOS, respectively. These levels are below current analytical method detection limits, meaning that any detectable concentration of PFOA or PFOS in water is an exceedance of the health advisory. In addition to lowering the PFOA and PFOS HAs in June 2022,  EPA also issued first-ever HAs for two other PFAS compounds: GenX chemicals and perfluorobutane sulfonic acid (PFBS), recommending 10 ppt for GenX and 2,000 ppt for PFBS.

PFAS is a class of contaminants that includes thousands of chemicals. PFOA, PFOS, PFBS, and GenX are just a few of them that have become notorious due to its presence in drinking water. As science evolves, other PFAS compounds continue to gain relevance. The current UCMR (UCMR5), published in December 2021, has its focus on PFAS. A total of 29 PFAS compounds will be monitored, with sample collection from 2023 – 2025, and completion of data reporting in 2026. The UCMR5 will provide EPA with a robust dataset for future PFAS regulatory decisions.

In the absence of enforceable federal guidelines, many of the Northeastern states have developed state-specific regulations, including both action levels and enforceable regulations (Table 1). Some states include standards on individual PFAS compounds (e.g., Connecticut, New Hampshire and New York) while others have focused on limits based on a sum of select PFAS; but overall, state regulations are continuing to evolve.

Table 1: Federal and State PFAS RegulationsPFOAPFOSPFNAPFHxSPFHpAPFDAGenXPFBS
USEPA (HAL)0.004 ppt0.02 pptN/AN/AN/AN/A10 ppt2,000 ppt
Connecticut (Action Level)16 ppt10 ppt12 ppt49 pptN/AN/AN/AN/A
Maine (MCL)20 ppt120 ppt120 ppt120 ppt120 ppt120 ppt1N/AN/A
Massachusetts (MCL)20 ppt120 ppt120 ppt120 ppt120 ppt120 ppt1N/AN/A
New Hampshire (MCL)12 ppt15 ppt11ppt18 pptN/AN/AN/AN/A
New York (MCL)10 ppt10 pptN/AN/AN/AN/AN/AN/A
Rhode Island (Interim Standard Level)20 ppt120 ppt120 ppt120 ppt120 ppt120 ppt1N/AN/A
Vermont (HAL)20 ppt120 ppt120 ppt120 ppt120 ppt1N/AN/AN/A

As part of EPA’s PFAS Strategic Roadmap, published in October 2021, the agency has laid out its commitments to Action for 2021 through 2024 and sets timelines by which they plan to take specific actions. As noted, the agency has followed through with its commitment to undertake nationwide monitoring for PFAS as part of UCMR 5 and issue health advisories. EPA is also expected to propose MCLs for PFOA and PFOS by the end of 2022, with a final rule expected in 2023. MCLs are usually higher than HAs as they take into consideration the detection limit of existing analytical methods, available treatment technologies, and cost. However, it is expected that Federal MCLs for PFOA and PFOS will be very low, possibly at the detection level.

In the midst of this changing regulatory landscape, Tighe and Bond has assisted clients across the Northeast with identifying PFAS, evaluating cutting-edge management and treatment options, and the design and construction of emergency and long-term treatment solutions.  Please contact us if our team of engineers and environmental scientists can help you navigate the ever evolvingPFAS standards or if you need testing or evaluation services.