Once hailed as miracle compounds for their unique ability to repel oil, fire and water, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) (collectively, perfluoroalkyl substances or PFAS) are now regarded as a threat to the environment.

From the 1950s to their phaseout starting in 2002, PFAS were used to produce an array of household products as well as the firefighting formula, aqueous film-forming foam (AFFF). In May 2016, the US Environmental Protection Agency (EPA) declared that PFOS and PFOA pose potential adverse effects for human health and the environment, and published Health Advisory Levels (HALs) of 70 parts per trillion (ppt) in drinking water.

Many expected these non-actionable levels to kick-start a wave of rulemaking by the states, setting enforceable action levels for regulators and private parties to address PFAS contamination. But the wave of rulemaking has not yet materialized – largely because of the unsettled science surrounding PFAS's interaction with and effect on humans and the environment. Recent events, however, foretell a shift toward more rulemaking in 2018.

As it stands, some states have already adopted the EPA's HALs (Washington, Connecticut, Colorado, Delaware, Iowa, Maine and New Hampshire) and two states have published their own more stringent guidance or risk levels (Vermont and Minnesota). But, thus far, we have not seen significant movement by the states to issue legally enforceable maximum contaminant levels (MCLs) – legal threshold limits on the amount of substances that are allowed in the environment.

Typically, MCLs are set as close as feasible to levels based on no adverse health effects. They may be used by regulators to issue fines or penalties, and by private plaintiffs in court actions. Therefore, setting MCLs requires public notice and comment, and the necessary science, data, studies, cost to benefit analysis, and justification to support a conclusion that a certain level of a contaminant in the environment is harmful. Few states have the resources to set MCLs on their own, particularly when the science is unsettled. This is where the hangup lies with PFAS regulations at the state level. Indeed, Pennsylvania has determined that it is too costly to set MCLs.

The PFAS basics are generally accepted: they persist in the environment and resist degradation by heat, light or microbial action. But hydrogeologists and engineers still debate key aspects of the harmfulness of PFAS: their volatility, how far and fast they move in groundwater, how they reach sensitive receptors, whether they can be age-dated or sourced and whether carbon-binding is the only remediation method available, to name just a few. Moreover, toxicologists do not agree on what level of exposure to PFAS is harmful to humans (ie, the "dose makes the poison" debate). Some argue, based largely on animal studies, that certain levels of PFAS are linked to developmental defects in fetuses and infants, cancer and impacts to the liver, thyroid, and immune system in humans. Others argue that human epidemiologic evidence does not show a causal link between PFAS and adverse health effects in humans. Even the key studies conflict – a study related to the DuPont Washington Works plant in West Virginia, finding a probable association between PFAS and cancer, conflicts with the results released this year from a study related to a Saint-Gobain site in New York, which found no such association. Without generally accepted peer-reviewed science in support of setting MCLs, sound rulemaking by the states is very difficult.

As 2017 closes, however, recent events indicate a shift toward more cooperation in the scientific community and more coordination between the states, and between the states and EPA.

First, on November 1, 2017, New Jersey announced it will be the first state to formally set MCLs for PFOA at 14 ppt in drinking water, the toughest standard in the country. The rulemaking process took three years and involved the work of multiple state subcommittees. New Jersey's DEP Commissioner Bob Martin has declared that "parties responsible for PFOA contamination will bear the costs associated with the testing, cleanup, and remediation." Scientists are now urging the state to move forward with setting MCLs for PFOS at 13 ppt, arguing that PFOS has been linked to cancer, developmental problems and changes to the human immune system.

The work performed by New Jersey – including its Health Effects Subcommittee, which was responsible for recommending health-based levels for PFOA – is now final, public and available for New Jersey's sister states to rely on for their own rulemaking. For instance, New York has created a state panel charged with determining the maximum legal amount of PFAS in drinking water and mandated to publish its first set of recommendations on PFAS limits by October 2018.

Next, on November 10, 2017, the California EPA Office of Environmental Health Hazard Assessment (OEHHA) added PFOA and PFOS to the California's Proposition 65 list of chemicals known to the state to cause reproductive toxicity under the Safe Drinking Water and Toxic Enforcement Act. Hence, releases of PFOA and PFOS to drinking water will be prohibited, and companies manufacturing, distributing or selling products containing PFOA or PFOS where exposure to PFOA or PFOS is over a safe harbor level will need to provide a clear and reasonable warning for that product.

This rulemaking sets the stage for California to move ahead on setting its own groundwater MCLs for PFAS. To add a chemical to the Proposition 65 list, it must go through a review and assessment process by state qualified experts concerning the chemicals' cancer or reproductive toxicity. Currently, California's Department of Toxic Substances Control (DTSC) has hinted at issuing its own advisory levels for PFAS very soon. With the OEHHA's rulemaking complete, the potential for DTSC or the State Water Board to move ahead with promulgating MCLs in 2018 has increased.

Third, on November 14, 2017, the Interstate Technology and Regulatory Council (ITRC) published the first three of six Fact Sheets that summarize the latest science and emerging technologies for PFAS. ITRC is a program of the Environmental Research Institute of the States, managed by the Environmental Council of the States. In January 2017, ITRC created the "PFAS Team" – made up of scores of scientists and regulators from around the country – with the mission "to produce concise technical resources that will help regulators and other stakeholders improve their understanding of the current science regarding PFAS compounds."

The Fact Sheets, which can be found here, are specifically tailored to the needs of state regulatory program personnel who are tasked with making decisions regarding PFAS-impacted sites. This group is led by top regulators from New Jersey and Minnesota, with participating members from dozens of sister states. The last three Fact Sheets are expected before the end of the year and the PFAS Team is working on an in-depth guidance document which will provide technical and regulatory guidance to the states, as well as a Fact Sheet focused on AFFF for 2018. There is little doubt that the extensive effort put into the Fact Sheets will be used by states when implementing current regulatory measures and, potentially, future rulemaking in 2018.

Fourth, on November 21, 2017, the EPA published a document titled "Protecting Public Health & Addressing PFAS Chemicals" in which the EPA vows to support states to address PFOA and PFOS by collecting and addressing the available data to share with the public. The EPA has further confirmed that it is ramping up its work to gather and evaluate additional scientific information about PFAS to identify risks and determine if it is necessary to set drinking water action levels, and to support state regulators in the effort to investigate and cleanup PFAS nationwide.

Fifth, on December 4, 2017, the EPA announced a cross-agency effort to address PFAS, declaring that "[p]rotecting public health is EPA's highest priority and through these efforts we are taking the lead to ensure that communities across the country have the tools they need to address these chemicals." As part of the agency's work, EPA will identify a set of near-term actions that EPA will take to help support local communities; enhance coordination with states, tribes and federal partners to address PFAS; increase research efforts to identify new methods for measuring PFAS; and, expand proactive communications efforts with states, tribes, partners and the American public about PFAS and their health effects. This announcement, coupled with the EPA's November 21 vow to support the states, defines the EPA's mission in 2018.

Finally, on December 12, 2017, the Fiscal Year 2018 National Defense Authorization Act (NDAA) was signed into law, which includes a nationwide health study on the impact of PFAS in drinking water. The new law, dubbed the "vesting in Testing Act," requires the Centers for Disease Control and Prevention to conduct a comprehensive study into the long-term health effects of PFOS and PFOA. This is significant, particularly given that the CDC's current position is that "studies in humans and animals are inconsistent and inconclusive but suggest that certain PFAS may affect a variety of possible endpoints . . . [and thus] confirmatory research is needed." Similarly, the EPA and the International Agency for Research on Cancer characterize PFOA and PFOS as potentially or possibly carcinogenic. This study, and others under way, are expected to have an impact on the designation status of PFAS as carcinogens by these agencies.

A more cohesive approach is coming

In the end, as we move into 2018, the laws governing the investigation and cleanup of PFAS contamination across the US, as well as the toxicology supporting private actions, remain fragmented. But recent signs indicate that more cohesion between the states and the states and EPA is coming in the New Year.

Until then, practitioners must pay close attention to the jurisdiction at hand when advising clients on assessing and mitigating risks attributable to PFAS – and much more when responding to agency enforcement actions, citizen suits or private lawsuits.