New US EPA Drinking Water Health Advisories for PFAS chemicals
The United States Environmental Protection Agency (EPA) released new Drinking Water Health Advisories (HAs) for PFAS chemicals on June 15, 2022, and announced $1 billion in grant funding to support infrastructure improvements that will reduce exposure risks. Most uses of Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonic acid (PFOS) have been phased out by U.S. manufacturers, although there are a limited number of ongoing uses, and these chemicals remain in the environment because they do not degrade.
As more and more instances of PFAS contamination are identified, there is an increasing concern of exposure, especially via drinking water ingestion. Correspondingly, there is an increasing concern among property owners, property operators, and water suppliers of potential liability. In the industry, the updated 2021 ASTM standard for Phase I Environmental Site Assessments now mentions PFAS as an emerging contaminant concern.
The new Health Advisory include new Interim HAs to replace the 2016 HAs for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) and new final HAs for perfluorobutane sulfonic acid and its potassium salt (PFBS) and for hexafluoropropylene oxide (HFPO) dimer acid and its ammonium salt (“GenX” chemicals).
The 2022 Drinking Water Health Advisory Compared to 2016:
|2016 HA in mg/L (ppt)
|2022 HA in mg/L (ppt)
|2 x 10-5 (20 ppt)
|4 x 10-9 (0.004 ppt) Interim
|2 x 10-5 (20 ppt)
|2 X 10-8 ( 0.02 ppt) Interim
|1 x 10-5 (10 ppt) Final
|0.002 (2,000 ppt) Final
To help put the low HA concentrations for the PFAS chemicals into perspective, the legally enforceable national Maximum Contaminant Levels for drinking water for lead, uranium, benzene, and trichlorethylene in ppt are 15,000, 30,000, 5,000, 5,000, respectively. The Interim HAs for PFOA and PFOS are near zero and the USEPA reports they are below their ability to detect at this time.
Diving into the science behind the Health Advisories
These non-enforceable and non-regulatory advisories indicate the level of drinking water contamination below which adverse health effects are not expected to occur over a lifetime of exposure. The Interim HAs for PFOA and PFOS were derived from the most sensitive non-cancer effect of PFOA and PFAs exposure identified in the draft EPA analyses. For PFOA and PFOS this was the decreased immunity in children observed in a human epidemiology study. There is evidence that PFOA is likely to be carcinogenic to humans and for PFOS there is “suggestive evidence of carcinogenic potential in humans,” however the USEPA has not derived a cancer risk concentration in water for PFOA or PFOS at this time and additional analyses of the cancer study data are ongoing for both PFOA and PFOS.
The USEPA’s final HAs for GenX chemicals and PFBS are based on animal toxicity studies. Studies of exposure to GenX chemicals reported health effects in the liver, kidney, immune system, development, and cancer, however, the most sensitive non-cancer effect among the available data and resulting from GenX exposure was an adverse liver effect. For PFBS, animal studies have reported health effects on the thyroid, reproductive system, development, and kidney following oral exposure, and the most sensitive non-cancer effect was an adverse effect on the thyroid (observed in a study of newborn mice exposed to the PFBS throughout gestation in the mothers).
The Interim HAs for PFOA and PFOS are subject to change because the underlying science is undergoing review by the USEPA’s Science Advisory Board. The USEPA notes that the Final HAs for PFBS and GenX may also be updated or removed upon finalization of the National Primary Drinking Water Regulation for these compounds.
HAs are often used as reference thresholds, especially in the absence of a promulgated drinking water standard, by federal, state, and local officials in monitoring plans, treatment goals, and in policy development. Therefore, the lower Interim HAs for PFOA and PFOS will likely be reflected in future federal, state, and local policies and decision making. In today’s announcement the USEPA also reiterated that it is moving forward with proposing a PFAS National Drinking Water Regulation in fall 2022.
How Can VERTEX Help?
Since 1995, VERTEX has been a global provider of environmental consulting, industrial hygiene, and remediation services. VERTEX works with a diverse number of industries and governments around the world to provide solutions that achieve environmental and sustainability goals as well as regulatory standards.
In regards to this newly released Health Advisories, VERTEX employs Environmental Professionals throughout the country experienced in identifying prior site uses where CERCLA defined hazardous substances and emerging contaminants are suspected as part of the Phase I ESA process.
VERTEX has also conducted subsurface investigations at fire-fighting training areas, airports and industrial facilities in several states to identify PFAS impacts for due diligence and site remediation activities. In addition, with VERTEX’s acquisition of Neptune Fire Protection Engineering, we have a design team experienced in replacing PFAS-based fire suppression systems.
VERTEX’s strategic nationwide locations allow us to mobilize on behalf of our clients to identify and mitigate challenges associated with environmental health and safety and compliances. To learn more about VERTEX’s Environmental Services, or to speak with an Environmental Expert, call 888.298.5162 or submit an inquiry.
Author: Bill Gibbons