In June, Loureiro provided our take on the class of emerging contaminants referred to as PFAS (per- and polyfluoroalkyl substances). Six months later, we have this update.
For those not familiar, beginning in the 1940s, PFAS were widely used in industry and consumer products. PFAS are synthetic compounds whose unique chemical structures give rise to distinct strength, durability, heat resistance, and stability properties. These characteristics made PFAS attractive chemicals to use so products would be resistant to grease, stains, and water. Consequently, various consumer products contain PFAS, including non-stick cookware, stain-resistant textiles, waterproof clothing, and food packaging. Manufacturers have also used PFAS as surfactants in certain Class B firefighting foams, such as aqueous film forming foams (AFFF), which are highly effective for fighting fires that have a flammable liquid component (e.g., jet fuel). This made PFAS-containing firefighting foams popular with fire stations, refineries, defense sites, large rail yards, and airports. PFAS are still a required component in some Class B foams currently used by the military and some airports. PFAS have also been used in aerospace, automotive, building and construction, and electronics applications. Due to growing concerns about potential health effects, production and use of some PFAS have been phased out over the past 15 years in the US.
The chemical properties that make PFAS so useful give rise to challenges in removing these substances once released to the environment. The carbon-fluorine bond is the shortest and strongest in chemistry, so PFAS do not readily degrade and are extremely persistent in the environment. PFAS can directly affect soil, groundwater, and surface water. Affected water may be used for potable or industrial uses then conveyed to a municipal wastewater treatment system, where PFAS may be discharged to surface water or contained in biosolids that are later applied to the ground. Also, PFAS can be components of air emissions and transported miles from the point of release.
Stakeholders are finding PFAS in groundwater, potable water supplies, treated wastewater, and surface water, to name a few. Environmental regulators at both the state and federal level continue to discuss the risks associated with PFAS as the science struggles to keep up with the speed of public interest and the pressure to “do something.” This leads stakeholders to ask “what do we do once we find it?”
The PFAS family contains thousands of different compounds, and the health effects are not currently well understood. Studies show ingestion of some PFAS may lead to adverse effects in laboratory animal studies and some epidemiological studies. Some studies link certain types of PFAS to cancer and other maladies. The fact that some PFAS can bioaccumulate in plant and animal tissue is of great concern, and several states have issued fish consumption advisories. Because of “suggestive evidence” of human carcinogenicity, the United States Environmental Protection Agency (USEPA) issued a Health Advisory with guidance indicating that action should be taken where perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) concentrations exceed 70 parts per trillion (ppt) – a very low concentration considering many other classes of chemicals are regulated at part per billion or part per million levels. Many states, including Connecticut, Maine, Massachusetts, and New Hampshire, followed suit with drinking water guidance or groundwater standards regulating PFOA and PFOS and sometimes other PFAS compounds at 70 ppt. Other states have settled on lower levels, like Vermont (20 ppt) and New Jersey (14 ppt). In addition to drinking water and groundwater, regulators are also working to develop similar guidance for other environmental media and the management of biosolids and wastewater.
However, the presence of a standard does not answer the question of when testing is required and what to do with the results. Loureiro’s observation is that the states are taking different approaches.
- New Hampshire requests that investigators look for a minimum of nine PFAS compounds at waste sites, although only two of the nine (PFOA + PFOS) have promulgated standards. The most uncertainty occurs where PFOA or PFOS is detected above laboratory reporting limits but below the 70 ppt standard. While the New Hampshire Department of Environmental Services expects at least one additional round of sampling to confirm concentrations, it has no guidance for cases where PFOS or PFOA is detected below 70 ppt over multiple rounds. Each site is handled on a case-by-case basis; however, we understand that full characterization of the PFAS source is needed to make the argument to stop sampling.
- In Connecticut, the Department of Energy and Environmental Protection (DEEP) is the lead for some sites, but for many others, a licensed environmental professional (LEP) directs investigation and remediation activities and “verifies” the completed work. At those sites, it is incumbent upon the LEP to evaluate whether PFAS are constituents of concern and if so, to investigate potential releases. Although DEEP has issued additional polluting substance criteria values for soil and groundwater that apply to the sum of five PFAS compounds, we understand that analysis for other PFAS compounds is expected unless sufficient records are available to document the absence of specific PFAS compounds.
- Massachusetts Department of Environmental Protection has determined that PFAS are hazardous materials subject to regulations under the Massachusetts Contingency Plan (MCP). Interim guidance regarding sampling and analysis for PFAS includes reference to 14 specific analytes; with no promulgated Method 1 standards for PFAS, these compounds would have to be addressed using either a Method 2 or Method 3 risk characterization. It is likely that some language around PFAS will find its way into the upcoming revisions to the Massachusetts Contingency Plan.
So what is the status? Suffice it to say, things remain in flux as regulators work on somewhat parallel tracks to develop standards and guidance for the regulated community. We expect PFAS will follow the same path as previous emerging contaminants such as 1,4-dioxane, which is now a commonly-required analysis for environmental media and wastewater discharges.
Loureiro continues to see significant challenges as scientists and regulators attempt to develop a comprehensive approach to PFAS.
- Currently, drinking water is the only environmental media for which there is a validated and USEPA-approved analytical method. We understand that methods for other environmental media are being reviewed and validated and will be issued within the next year or two. In the interim, commercial laboratories use modified versions of the drinking water method or alternate methods for analysis of other media, such as soil and groundwater. Since these modifications and alternate methods are laboratory-specific, PFAS results from different laboratories may not be directly comparable. Careful selection of analytical method and laboratory is very important.
- In many places, PFAS are being regulated at low concentrations – ppt levels for some media. As we start to sample more locations at lower concentrations, we may find PFAS are more ubiquitous than previously thought. Removing PFAS from waste or water to ppt concentrations will pose another challenge.
- Due to their widespread uses, PFAS are likely pervasive in municipal wastewater treatment streams and landfills and identifying the sources of the PFAS will be challenging.
- Although PFAS have not been identified as hazardous substances under the Resource Conservation and Recovery Act (RCRA) or the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), states have begun to add PFAS compounds to their lists of hazardous substances or hazardous waste.
Loureiro is tracking the understanding of PFAS toxicity and health effects as studies continue to be released as well as the development of laboratory methods, regulations, and remediation technologies. Due to the current regulatory environment, our advice to clients is very case-specific, but generally follows a phased approach beginning with an assessment of whether PFAS-containing substances may have been used at their facilities.
Contributed by: Luke Chmielecki, Karen Goldenberg, P.G., L.E.P., and Jacqueline Oakes, P.E.