Posted on February 13, 2019 by Tom Burack
In an age in which the names of chemicals are so complicated that even scientists refer to them by acronyms, an entire class of manmade chemicals created to improve human lives is now in the midst of performing an acrobatic stunt, back-flipping from being the darling of industrial and consumer products to being the contaminants that are now the nemesis of many communities: Poly- and Perfluoroalkyl Substances — commonly referred to as “PFAS” – are also coming to be recognized as something else with the same acronym, namely a “Problem For All States”. Due to their unique chemical properties and the growing public demands for timely regulatory response actions at the local level in the absence of definitive federal leadership, PFAS compounds can be expected to remain a Problem For All States for many decades to come.
Chemical engineers, starting in the 1940s, made some remarkable discoveries: the combination of carbon and fluorine atoms into long-chained synthetic organic molecules results in compounds that variously can repel oil, water, grease or stains, resist high temperatures, and reduce friction. These properties, combined with high durability, made these newfound PFAS compounds ideal for innumerable industrial and consumer purposes. For example, some of the most commonly used PFAS are: perfluorooctanoic acid (PFOA), as a repellent coating for textiles, paper products and cookware; and, perfluorooctanesulfonic acid (PFOS), in fire-fighting foams, carpet treatments, and mist suppressants in metal plating operations. As a broad class, there are approximately 3,000 different PFAS compounds, some of which are precursors to other PFAS compounds, and various of which may co-occur with each other. Commonly known household products containing or made with PFAS compounds have included DuPont’s Teflon®, 3M’s ScotchGard®, and Gore’s Gore-Tex®, to name but a few. Unfortunately, some of the most commonly used PFAS compounds are also highly persistent, mobile, and non-biodegradable. Consequently, worldwide production and uses of PFAS have resulted in their nearly ubiquitous presence throughout the environment, including in soils, sediments, surface and groundwater.
Moreover, because they can also bioaccumulate, PFAS compounds can be found in animals and humans in parts per billion (ppb) concentrations. Laboratory studies of PFAS health impacts on animals point toward elevated cholesterol levels, low infant birth weights, immune system effects, cancer (PFOA), and thyroid hormone disruption (PFOS). While peer-reviewed human epidemiological studies of PFAS exposure have been less numerous or definitive to date, when combined with the laboratory animal studies there have been sufficient data to support the establishment of Lifetime Health Advisories for PFOA and PFOS by the US EPA in 2016 and the promulgation of regulatory limits to protect drinking water supplies by a growing number of states.
In the United States, the first health and environmental concerns arose in connection with PFAS manufacturing facilities and their waste disposal practices in West Virginia and Ohio in the late 1990’s and in Minnesota in the early 2000’s. Between 2000 and 2002, 3M voluntarily agreed to phase out the further manufacture of most long-chain PFAS compounds, and DuPont and other US manufacturers followed suit. Today, under a set of Significant New Use Rules (SNURs) promulgated by the US EPA under the Toxic Substances Control Act (TSCA), most long-chain PFAS are allowed to be used or imported only for limited purposes and in select industries or applications. Further restrictions have been proposed and shorter chain PFAS compounds are increasingly being used as substitutes, but even these may present significant environmental and public health concerns, as illustrated by the ongoing GenX contamination situation in the Cape Fear Watershed of North Carolina. (See, e.g., https://www.northcarolinahealthnews.org/2017/08/17/genx-pollution-what-happened-when/)
Ever-more sensitive laboratory technology can now detect PFAS at parts per trillion (ppt) concentrations, and it’s become evident that the more than five decades of unregulated use of PFAS has left an indelible signature in landfills, wastewater, waterways, and communities far and wide. To date, the New Hampshire Department of Environmental Services has amassed perhaps the largest single dataset on PFAS contamination in groundwater, surface water and soils of any state: roughly 6,000 samples from some 3,500 locations. This continuously growing dataset already shows some noteworthy trends: sampling of 429 public water supply wells found that 7 (1.6%) contained PFOA or PFOS above 70 ppt (the US EPA LHA value which NH adopted as its groundwater cleanup standard); but NH has now proposed to lower its standard for PFOA to 38 ppt, which once all of NH’s public water systems have been sampled is likely to put another 16 or so in noncompliance. More than 50% of the existing known contaminated industrial sites sampled so far in NH contain elevated levels of PFAS. Every NH landfill leachate system sampled to date has a PFAS signature, and the monitoring wells around the older closed but unlined landfills indicate 46% exceed the groundwater standards. Fire stations and training sites are also potential sources, as are municipal wastewater treatment plants, biosolids storage and application sites, car washes, airports (military and civilian), and a wide variety of other operations. Typical contamination vectors include not only historical releases directly to soils, groundwater or surface waters, but also atmospheric deposition resulting from airborne emissions of PFAS that subsequently contaminate other media, including groundwater.
Due to the combination of their durability, persistence, mobility, multiple possible release mechanisms, and extremely low detection limits, the simple reality is that if you look for PFAS in the environment you will find them. The corollary is that if you haven’t found them, you’re probably not looking in the right places. While some public officials may believe that PFAS are not a problem in their states or regions, the public and elected officials – sensitized by the story of lead contamination in the water supply of Flint, Michigan – are asking questions, demanding answers, and expecting action. In 2018, the US EPA held a “national summit” on PFAS contamination and announced that it would consider whether to establish public drinking water standards, Maximum Contaminant Levels (MCLs), for some PFAS, and whether to list certain PFAS compounds as hazardous substances under CERCLA. More recently, EPA officials have indicated that MCLs for PFAS are unlikely, but that EPA is considering broader use of its emergency administrative order authority under Section 1431(a) of the Safe Drinking Water Act to address PFAS contamination situations on a site-by-site basis. In the meantime, members of Congress have introduced bipartisan legislation to require US EPA to list all PFAS compounds as CERCLA hazardous substances and a growing number are joining a bipartisan Congressional PFAS Task Force.
The most consequential regulatory action, however, has been at the state level, which is where considerably more future action should be expected. As of January 2019, at least eight states had adopted or proposed guidance values or regulations setting acceptable concentrations of various PFAS compounds in groundwater, drinking water, surface water, or soil, including Alaska, Colorado, Michigan, Minnesota, New Hampshire, New Jersey, New York and Vermont. This list is expanding rapidly, as is the list of state legislatures that have regulated or are considering regulating the use of PFAS compounds, including California, Michigan, Minnesota, North Carolina, New Hampshire, New York, Pennsylvania, Rhode Island, Vermont and Washington. The Environmental Council of States (ECOS), the national, nonpartisan, nonprofit association of state and territorial environmental agency leaders, has established a PFAS workgroup, and its research arm, the Environmental Research Institute of the States (ERIS) has a large and active technical team that has published a number of fact sheets on PFAS through the Interstate Technology Regulatory Council (ITRC).
Regulatory strategies and cleanup standards for the same compounds often differ from state to state: for example, in Vermont the groundwater standard is 20 ppt for PFOA and PFOS individually or in combination, while in New Hampshire the standard for PFOA and PFOS individually or in combination is 70 ppt, and a proposed rule would lower the individual standard for PFOA to 38 ppt. The process of setting health-based regulatory standards varies greatly by jurisdiction, and different standards are typically attributable to differences in which toxicity data are selected and how they are interpreted, differences in toxicity factors (i.e., multipliers or margins of safety), how animal test results are extrapolated to humans, exposure assumptions, life stage used, and sources of exposure (drinking water versus non-drinking water). Should EPA choose not to adopt MCLs for PFAS compounds, it’s likely that more and more states will find themselves weighing these and other variables as they set their own regulatory standards and seek to explain why they may be either higher or lower than those of their neighboring states.
Because they are ubiquitous, PFAS compounds present a set of challenges that every state will ultimately need to quantify and regulate, all the while communicating with the public, the regulated community and elected officials about the steps they’re taking and why their approach is an appropriately protective risk management strategy. The lack of a comprehensive national regulatory approach and federal standards for PFAS compounds makes the problem all the more challenging for states, as they will forever need to justify their own approach in comparison with those of other states. All of which suggests that PFAS are, and for the foreseeable future will remain, a Problem For All States.