EPA Adopts New PFAS Requirements Impacting Municipalities, School Units, and Tribal Nations

In late April 2024, the Environmental Protection Agency (EPA) finalized two PFAS rules that will impact municipal, school, and tribal entities.

The first rule sets maximum contaminant levels (MCLs), or drinking water standards, for five separate PFAS compounds and a hazard index for a sixth PFAS compound. Together, the thousands of PFAS compounds are known as “forever chemicals.” This first new EPA rule applies to any water system (including any private well) that provides drinking water to at least 15 service connections or serves an average of at least 25 people for at least 60 days a year. The new rule will require such systems to monitor for PFAS and, starting in 2029, effectively treat PFAS that exceed these MCLs.

The second new EPA rule designates two PFAS compounds as “hazardous substances” under the federal Superfund Law. Superfund was established in the 1970s in response to the Cuyahoga River catching fire to impose strict, joint and several liability on any entity that engaged with a process that touched certain highly dangerous substances, known as hazardous substances. By designating these two PFAS compounds as hazardous substances, such liability will attach to any entity who owned or operated a facility involved in their discharge to the environment. Because the Maine Superfund Law includes broader language regarding the scope of hazardous substances, Maine DEP may treat all six PFAS compounds for which there is an MCL as hazardous substances subject to state Superfund liability. State Superfund liability exists in parallel to federal Superfund liability, meaning one does not excuse the other – they are additive.

Below are specifics about the two new rules. Because this area of law is evolving and complicated, please don’t hesitate to call Stacey Caulk at (207) 253-0563 or Joanna Tourangeau at (207) 253-0567 to better understand how the rules could affect your facilities and operations.

Drinking Water Standards – What’s changed?

On April 10, 2024, the EPA finalized a National Primary Drinking Water Regulation (NPDWR) setting Maximum Contaminant Levels (MCLs) for five individual PFAS chemicals, as well as a combined Hazard Index Level for two or more of certain PFAS, including PFBS. The new MCLs are as follows:

An MCL is an enforceable standard that it is “the highest level of a contaminant that is allowed in drinking water.”1 An MCLG is a “goal” and thus not enforceable.

Hazard Index (HI) is a sum of fractions and it is calculated as follows:

Perform the above calculation with all sampling data taken in the past year to get the HI values for each sampling set (see the applicable timeframes below). Add the HI values and divide by the total number of sampling sets to get the average HI over the past year (e.g., if samples were taken 4 times during the year, you would have 4 HI values and this would be the denominator). If this average calculation exceeds 1, the Hazard Index has been exceeded and the water supply is in violation.2

Who must comply with this new rule?

The MCLs apply to public water systems that qualify as Community Water Systems or Non-Transient Non-Community Water Systems. A public water system is a system that “provides water for human consumption through pipes or other constructed conveyances to at least 15 service connections or serves an average of at least 25 people for at least 60 days a year.”3

Community Water Systems include “any public water system that supplies water to the same population year-round.”4

Non-Transient Non-Community Water Systems include any “public water system that regularly supplies water to at least 25 of the same people at least six months per year. Some examples are schools, factories, office buildings, and hospitals that have their own water systems.”5

What does this mean for public water systems (PWSs)?

PWSs have until April 26, 2027, 3 years from the date the final rule was published in the Federal Register, to conduct required initial monitoring for the above PFAS compounds. This monitoring must be done at all entry points to the public water system (your sampling personnel will be familiar with these locations) and must be done:

  • quarterly per year for Groundwater Systems serving more than 10,000 customers
  • twice per year for Groundwater Systems serving 10,000 or fewer customers
  • quarterly per year for all Surface Water Systems

Starting April 26, 2027, the PWS must:6

  • publish the results of the initial monitoring – regardless of what they show – in your regular Annual Water Quality report;
  • begin regular monitoring at all entry points (at least annually, depending on prior results) for the above PFAS and include results in an Annual Water Quality report; and
  • notify customers/consumers of any monitoring or testing procedure violations.

Starting April 26, 2029, the PWS must comply with the above MCLs and Hazard Index. This means that any treatment system must be operational and effectively treating PFAS below the MCLs no later than April 26, 2029. The PWS must also start notifying its customers any time the water supply exceeds the above MCLs or Hazard Index.7

How do these new drinking water standards impact requirements under Maine State law?

Maine law already mandates that all public water systems that qualify as Community Water Systems or Non-Transient, Non-Community Water Systems (such as schools and daycares) sample drinking water for six PFAS compounds (PFOA, PFOS, PFHxS, PFNA, PFHpA, PFDA) and report these results to the Maine Department of Health and Human Services (DHHS) Drinking Water Program.8 Maine implemented an interim standard of 20 parts per trillion for these six PFAS (alone or in combination). The Maine DHHS expects to update this interim standard with final standards at least as stringent as those announced by the EPA.

EPA’s new rule addresses four of the PFAS compounds that Maine law already regulates. Public water systems will need to begin sampling for HFPO-DA and PFBS, along with the six PFAS compounds they are already required to sample, no later than April 26, 2027. However, if the Maine DHHS updates its standards as expected, Maine will likely require sampling for these two additional PFAS by an earlier date.

Public water systems are currently required to comply with Maine’s interim standard of 20 parts per trillion for six PFAS compounds (alone or in combination) and will also be required to comply with the EPA’s new MCLs beginning April 26, 2029. However, if the Maine DHHS updates its standards as expected, Maine will likely require compliance with updated standards before April 26, 2029.

What impacts do the new EPA rules have on governmental entities’ liability under the state and federal versions of CERCLA (i.e., Superfund)?

The new MCLs for PFAS compounds will impact liability for entities who own or operate (or formerly owned or operated) properties where PFAS was stored, released, disposed, or treated.

Further, the EPA has just designated two PFAS – PFOA and PFOS – as “hazardous substances” under CERCLA, the federal Superfund Law.9 This means any entity, including a governmental entity, that owns or operates (or formerly owned or operated) property at which PFOA or PFOS has been stored, released, or disposed of, or otherwise came to be located, whether knowingly or unknowingly, could be subject to federal liability for containment, clean-up, remediation, and costs.

While the EPA does not have authority to exempt entities from CERCLA, the EPA did issue a “CERCLA enforcement discretion policy”10 outlining its intention to not focus on the following entities: public water suppliers, landfills, MS4s, fire departments, publicly-owned airports, publicly-owned wastewater treatment plants, and farms where biosolids were applied to the land. Rather, the EPA intends to “focus enforcement on parties who significantly contributed to the release of PFAS chemicals into the environment, including parties that have manufactured PFAS or used PFAS in the manufacturing process, federal facilities, and other industrial parties.”11

This, however, is not a guarantee that an entity will be free from federal liability given that this is just an EPA policy. Further, there is still the possibility that the responsible parties who are subject to enforcement by EPA will seek contribution against these entities as is allowed by CERCLA. EPA has stated that it will work with these major responsible parties in any CERCLA settlement to attempt to require “those settling parties to waive their rights to sue” certain contributing entities.12

Now that PFOA and PFOS are designated as “hazardous substances” at the federal level, they are automatically designated as hazardous substances under the Maine Uncontrolled Sites Act, Maine’s Superfund Law.13 The Maine Superfund’s definition of a hazardous substance also includes all substances that meet the criteria for “pollutants or contaminants” under federal Superfund.14 Therefore, because EPA established MCLs for all six PFAS compounds, Maine may take the position that those six PFAS compounds are “pollutants or contaminants” under CERLCA and are therefore hazardous substances under Maine’s Superfund Law. This means that any entity, including a governmental entity, could be subject to state liability for containment, clean-up, remediation and costs for any property that it owns or operates (or formerly owned or operated) and at which any of these six PFAS substances has been stored, released, or disposed of, or otherwise came to be located, whether knowingly or unknowingly. Such entities could likewise be subject to additional handling, recordkeeping and reporting, and transportation requirements.

Need help?

This is a very complex area of the law, involving state, federal and, in some cases, tribal laws. If you have liability concerns or questions about any of the above, please reach out to us. We are available to further discuss the new rules and how they impact you. Please do not hesitate to contact Drummond Woodsum attorneys Stacey Caulk or Joanna Tourangeau if you have questions.


[1] https://www.epa.gov/system/files/documents/2024-04/pfas-npdwr_fact-sheet_general_4.9.24v1.pdf

[2] https://www.epa.gov/system/files/documents/2023-03/How%20do%20I%20calculate%20the%20Hazard%20Index._3.14.23.pdf

[3] https://www.epa.gov/dwreginfo/information-about-public-water-systems

[4] https://www.epa.gov/dwreginfo/information-about-public-water-systems

[5] https://www.epa.gov/dwreginfo/information-about-public-water-systems

[6] https://www.epa.gov/system/files/documents/2024-04/pfas-npdwr-presentation_4.9.24_overview.pdf

[7] https://www.epa.gov/system/files/documents/2024-04/pfas-npdwr-presentation_4.9.24_overview.pdf

[8] https://www.mainelegislature.org/legis/bills/getPDF.asp?paper=SP0064&item=3&snum=130

[9] https://www.epa.gov/newsreleases/biden-harris-administration-finalizes-critical-rule-clean-pfas-contamination-protect

[10] https://www.epa.gov/system/files/documents/2024-04/pfas-enforcement-discretion-settlement-policy-cercla.pdf

[11] https://www.epa.gov/newsreleases/biden-harris-administration-finalizes-critical-rule-clean-pfas-contamination-protect

[12] https://www.epa.gov/system/files/documents/2024-04/pfas-enforcement-discretion-settlement-policy-cercla.pdf

[13] 38 M.R.S. Section 1362(1)(H).

[14] 38 M.R.S. Section 1362(1)(H).


Legal Disclaimer: The information provided in this alert does not, and is not intended to, constitute legal advice; instead, all information and content is provided for general informational purposes only.