In the absence of an enforceable federal drinking water standard for per- and polyfluoroalkyl substances ("PFAS"), many states have started regulating PFAS compounds in drinking water.  The result is a patchwork of regulations and standards of varying levels, which presents significant operational and compliance challenges to impacted industries.  This client alert surveys the maximum contaminant levels ("MCLs"), as well as guidance and notification levels, for PFAS compounds – typically perfluorooctane sufonic acid ("PFOS") and perflurooctanic acid ("PFOA")  – in drinking water across the United States.

I. Federal Health Recommendations and Advisory

The United States Environmental Protection Agency ("EPA") has issued a Lifetime Drinking Water Health Advisory Level of 70 ppt for PFOS and PFOA.  EPA's Health Advisory is non-enforceable, but is intended to provide technical information to state agencies and other public health officials regarding health effects, analytical methodologies, and treatment technologies associated with drinking water PFAS contamination.  Numerous states have adopted and/or used EPA's recommended 70 ppt PFAS concentration limitation for drinking water (e.g., Alaska, Colorado, Connecticut, Delaware, New Mexico, and Ohio).

According to the PFAS Strategic Roadmap, EPA expects to issue proposed drinking water limits, or MCLs, for PFOA and PFOS in the fall of 2023.  A national drinking water limit will require the entire country to evaluate the concentration of these two compounds in drinking water, and to implement treatment systems and permit limits to achieve the MCLs.

II. State Regulations

Until the federal government enacts MCLs for PFOA and PFOS, the regulatory landscape for PFAS compounds in drinking water consists of an array of widely-varying state-promulgated standards and regulations.  For example, one of the smallest allowable concentrations is 5.1 ppt (California; PFOA only), and one of the largest values is 667,000,000 ppt (Nevada; PFBS only).  For further detail, the chart below illustrates the significance of the discrepancies between the regulatory levels for PFOA and/or PFOS.

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The map and chart below are current as of March 1, 2022.  Two states, including Pennsylvania (MCLs for two PFAS substances) and Rhode Island (Interim Drinking Water Standards for six PFAS substances), have proposed, but not yet promulgated, drinking water regulations for PFAS.  Additionally, Delaware, Maine, and Virginia have enacted legislation to establish MCLs for PFAS compounds for drinking water, so implementing regulations in those jurisdictions may be forthcoming.  Moreover, Wisconsin is currently involved in an administrative process to establish drinking water standards.  These proposals underscore that state-driven guidance and requirements surrounding the PFAS drinking water regulations are developing quickly throughout the country.

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Participating States

Concentration Level

Type of Regulation

Adoption Status

California

5.1 ppt

PFOA (Notification)

Regulation and Related Information

Michigan

6 ppt

PFNA (MCL)

Regulation and Related Information

California

6.5 ppt

PFOS (Notification)

Regulation and Related Information

Michigan

8 ppt

PFOA (MCL)

Regulation and Related Information

Washington

9 ppt

PFNA (Notification)

Rules and Related Information

Washington

10 ppt

PFOA (Notification)

Rules and Related Information

New York

10 ppt

PFOA and PFAS (MCL)

Regulation and Related Information

New Hampshire

11 ppt

PFNA (MCL)

Regulation and Related Information  

New Hampshire

12 ppt

PFOA (MCL)

Regulation and Related Information  

New Jersey

13 ppt

PFNA and PFOS (MCL)

Regulation and Related Information

New Jersey

14 ppt

PFOA (MCL)

Regulation and Related Information

Minnesota

15 ppt

PFOS (Guidance)

Health Advisory

New Hampshire

15 ppt

PFOS (MCL)

Regulation and Related Information  

Washington

15 ppt

PFOS (Notification)

Rules and Related Information

Michigan

16 ppt

PFOS (MCL)

Regulation and Related Information

New Hampshire

18 ppt

PFHxS (MCL)

Regulation and Related Information  

Massachusetts

20 ppt (Stated in the regulation as 20 ng/L)

6 PFAS substances combined:  PFOA, PFOS, PFHxS, PFNA, PFHpA, and PFDA (MCL)

Regulation and Related Information

Vermont

20 ppt (Stated in the regulation as 0.000002 mg/L)

5 PFAS substances combined:  PFOA, PFOS, PFHpA, PFHxS, and PFNA (MCL)

Regulation and Related Information

Maine

20 ppt (stated in the Interim Drinking Water Standard as 20 ng/L)

6 PFAS substances combined:  PFOA, PFOS, PFHxS, PFNA, PFHpA, and PFDA (Notification)

Interim Drinking Water Standard and Related Information

Ohio

21 ppt

PFNA (Guidance)

Statewide PFAS Action Plan and Related Information

Oregon

30 ppt

4 PFAS substances combined:  PFOS, PFOA, PFHxS, and PFNA (Guidance)

Health Advisory and Related Information

Minnesota

35 ppt

PFOA (Guidance)

Health Advisory

Minnesota

47 ppt

PFHxS (Guidance)

Health Advisory

Michigan

51 ppt

PFHxS (MCL)

Regulation and Related Information

Washington

65 ppt

PFHxS (Notification)

Rules and Related Information

Connecticut

70 ppt

5 PFAS substances combined:  PFOS, PFOA, PFHpA, PFHxS, and PFNA (Notification)

Health Advisory

Colorado

70 ppt

3 PFAS substances combined:  PFOS, PFOA, and PFNA (Guidance)

Translation Level

Alaska, Delaware, New Mexico, and Ohio

70 ppt

Adopt the EPA Standard:  PFOS and PFOA combined (Notification and Guidance)

Alaska:  Action Level

Delaware:  Guidance Policy

New Mexico:  Toxic Pollutant Standard

Ohio:  Statewide PFAS Action Level

Ohio

140 ppt

PFHxS (Guidance)

Statewide PFAS Action Plan and Related Information

Maryland

140 ppt

PFHxS (Guidance)

Health Advisory

North Carolina

140 ppt

GenX or HFPO-DA (Guidance)

Health Advisory

Washington

345 ppt

PFBS (Notification)

Rules and Related Information

Michigan

370 ppt

Gen X or HFPO-DA (MCL)

Regulation and Related Information

Michigan

420 ppt

PFBS (MCL)

Regulation and Related Information

California

500 ppt (Stated in the regulation as 0.5 ppb)

PFBS (Notification)

 

Regulation and Related Information

Colorado

700 ppt (Stated in the regulation as 700 ng/L)

PFHxS (Guidance)

Translation Level and Related Information

Ohio

700 ppt

Gen X or HFPO-DA (Guidance)

Statewide PFAS Action Plan and Related Information

Minnesota

2,000 ppt

PFBS (Guidance)

Health Advisory

Minnesota

7,000 ppt

PFBA (Guidance)

Health Advisory

Ohio

140,000 ppt

PFBS (Guidance)

Statewide PFAS Action Plan and Related Information

Colorado

400,000 ppt (Stated in the regulation as 400,000 ng/L)

PFBS (Guidance)

Translation Level and Related Information

Michigan

400,000 ppt

PFHxA (MCL)

Regulation and Related Information

Nevada

667,000 (stated in the regulation as .667 µg/L)

PFOA and PFOS (Guidance)

Basic Comparison Levels

Nevada

667,000,000 (stated in the regulation as 667 µg/L)

PFBS (Guidance)

Basic Comparison Levels


No regulations:

Alabama, Arizona, Arkansas, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Montana, Nebraska, North Dakota, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming

Key:

Notification

A corporate representative must inform an appropriate state official that a drinking water concentration in a water source owned or operated by the corporation (public well, supply tank, etc.) is above the limit.  A water supply system also may have to inform its customers if there are any samples that exceed the PFAS values.

Guidance

The state establishes recommended concentration limits for one or more PFAS substances, but no notification or other action is required if concentrations exceed the recommended limits.

MCL

MCLs establish the maximum amount of a PFAS compound that can be present in drinking water.  Treatment facilities that supply drinking water must ensure that these limits are met by treating and filtering the drinking water, and also by limiting the discharge of PFAS compounds through permits.


III. How Do These Limits Impact Businesses?

MCLs set the maximum concentration of a given contaminant that can be present in drinking water.  Publicly owned treatment works ("POTWs") and drinking water systems are ultimately responsible for meeting the applicable MCLs and are required to ensure that drinking water distributed to the public meets these limits.  In order to do that, POTWs and state agencies often include discharge limits in the permits of upstream dischargers to the POTW or other drinking water systems to ensure that the effluent the treatment facility receives can be adequately filtered and treated to comply with the MCLs.

Businesses that currently or historically have used PFAS compounds, or have reason to believe that they may be present in their process wastewater effluent, should evaluate the following considerations: 

  • Whether their wastewater discharges, following treatment by the POTW or other treatment facilities, are eventually released to sources that are used for drinking water;
  • Whether their discharge contains any of the PFAS compounds that are regulated in their jurisdiction; and
  • Whether they are likely to be subject to permit conditions limiting the allowable concentration of PFAS compounds in their wastewater discharges. 

Acquiring this information will allow businesses to determine whether they need to modify their operations to reduce or eliminate PFAS from their waste stream to achieve compliance with an existing standard, or in anticipation of likely future permit conditions.

IV. Conclusion

The regulation of PFAS substances in drinking water will continue over the next several years as additional research is conducted on potential health impacts, and as regulators at both the federal and state levels develop a deeper understanding of the prevalence of PFAS compounds in drinking water and the efficacy of different MCLs.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.