It is hard to call per- and polyfluoroalkyl substances (PFAS) a category of "emerging" contaminants given the amount of attention PFAS is receiving these days, but the regulation of PFAS throughout the country is certainly still developing. Pennsylvania is the latest jurisdiction to propose drinking water standards for PFAS, with the proposed maximum contaminant levels (MCLs) examined below.
If adopted, it would be the first time Pennsylvania has set a state-specific drinking water standard for any substance.
PFAS are a class of synthetic chemicals that have been used since the 1940s to make products that are resistant to water, heat, and oil. These products include cookware, carpets, clothing, fabrics for furniture, paper packaging for food, and other materials that are resistant to water, grease, or stains. They are also used in firefighting foams and in a number of industrial processes.
What Is an MCL?
MCLs set the maximum concentration at which a particular contaminant can be present in drinking water. They are established to protect the public against potential health risks.
MCLs are typically developed by the Environmental Protection Agency under the Safe Drinking Water Act. But states may set their own MCLs, especially in the absence of a federal MCL.
MCLs differ from secondary standards, such as guidance, in that they are legally-enforceable. For example, exceeding an MCL can result in the imposition of fines and other penalties.
Notably, MCLs apply to water providers and are different than remediation standards for environmental media. In many cases, remediation standards are set to match MCLs. If a release from a facility causes an exceedance of an MCL in a supply well, the responsible party may be required to provide treatment.
Pennsylvania's Proposed Regulation
With no federal MCL in place for PFAS compounds in drinking water, Pennsylvania is the latest jurisdiction that has set out to enact its own regulations.
The Pennsylvania Department of Environmental Protection (DEP) recently proposed a new regulation that would set MCLs for two PFAS compounds-18 parts per trillion (ppt) for perfluorooctane sulfonic acid (PFOS) and 14 ppt for perfluorooctanoic acid (PFOA).
This proposed rule is the outgrowth of an executive order signed by Gov. Tom Wolf (D) in September 2018, which established a PFAS action team. According to that EO, the function of the action team is to, among other things, "ensure drinking water is safe" and "reduce risks to drinking water and the environment."
The proposed rule is currently in the required public notice-and-comment phase, which closes on April 27.
EPA's Standard Only Advisory
The EPA has set a lifetime health advisory level (HAL) of 70 ppt for PFOS and PFOA. This is not a legally-enforceable MCL, and is instead non-enforceable and non-regulatory. In other words, the EPA's HAL for PFAS serves as a recommendation for the level at which states may choose to set their standard.
In October 2021, the EPA announced its PFAS strategic road map, which will likely result in very conservative PFAS standards being promulgated in the near future. But for now, many states have chosen to enact their own standards, leading to patchwork frameworks throughout the country.
What Are Other States Doing?
A number of states have chosen to adopt notification standards based on the EPA's recommended limit of 70 ppt for PFAS in drinking water. These states include Alaska, Colorado, Delaware, Maine, New Mexico, and Ohio.
Connecticut has also adopted a 70 ppt notification standard, but its standard only applies to five PFAS substances-PFOA and PFOS, plus perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHxS), and perfluoroheptanoic acid (PFHpA).
Meanwhile, a few states have adopted more restrictive standards than those proposed in Pennsylvania. For example:
- New York's MCLs are 10 ppt for both PFOS and PFOA;
- Michigan's MCLs are 16 ppt for PFOS and 8 ppt for PFOA;
- New Hampshire's MCLs are 15 ppt for PFOS and 12 ppt for PFOA; and
- Washington's MCLs are 15 ppt for PFOS and 10 ppt for PFOA.
New Jersey has stricter MCLs for PFOS (13 ppt) than what Pennsylvania has proposed, but New Jersey's MCL for PFOA (14 ppt) is the same as Pennsylvania's.
Minnesota (35 ppt) appears to be the only state that has issued guidance for a more restrictive PFOA standard than the EPA's HAL, but less restrictive than Pennsylvania's proposed regulation.
For states that have regulations for PFAS compounds other than PFOS or PFOA, the allowable concentrations tend to be higher. However, PFOS and PFOA are the only compounds captured under Pennsylvania's proposed new regulation.
Pennsylvania appears to be next in the growing list of jurisdictions that are taking it upon themselves to establish regulatory standards for PFAS. While federal standards for some PFAS, including PFOS and PFOA, are likely imminent, the race is on to see how low standards can go.
As more states weigh in, the regulated community should expect to see additional PFAS being regulated and standards being set for other environmental media such as soil and surface waters.
Originally published by Bloomberg Law on the 25th of March, 2022. (Reproduced with permission. Published March 25, 2022. Copyright 2022 The Bureau of National Affairs, Inc. 800-372-1033.)
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