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There is much debate today about the prevalence of PFAS (per- and polyfluoroalkyl substances) in groundwater, the potential health effects of exposure to PFAS in groundwater, and the development of groundwater cleanup standards by the USEPA and state environmental protection departments. Less talked about (at least in the news media) is subject to remediation. Despite the end of the “forever” label, can these chemicals be effectively remedied in-situ in groundwater?
Answering this question may be aided by a remediation pilot study being conducted at a PFAS site in East and West Rockhill Townships, Bucks County, Pennsylvania – the Ridge Run PFAS site. Ridge Run became a state superfund site (under Pennsylvania’s Hazardous Sites Cleanup Act (“HSCA”), 35 PS §§ 6020.102-6020.1303) in 2016 when a combined concentration of PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate) exceeded the U.S. The Environmental Protection Agency’s (EPA) then-current Health Advisory Level (HAL) (70 parts per trillion) was detected in a public water supply well.
Although it has been reported that one source (if not the source) of PFAS at Ridge Run may have been the use of PFAS-containing firefighting foam to extinguish a local tire fire in 1986, the Pennsylvania Department of Environmental Protection (DEP) has not yet pursued enforcement against any alleged responsible parties. Therefore, DEP has self-funded the soil and groundwater investigation and is funding both the installation and maintenance of filtration systems for private properties served by impacted drinking water wells. In addition, DEP is funding a pilot project involving the injection of the Regenesis product known as PlumeStop® into the contaminated aquifer.
As described by PaDEP, the goal of the pilot study is to determine the effectiveness of PlumeStop® in creating “a permeable, underground barrier that will allow groundwater to flow through it, but not PFOA and PFOS.”
As described by Regenesis, PlumeStop® is a “liquid colloidal activated carbon” that “effectively transforms the contaminated groundwater stream itself into a purifying filter.” In simplest terms, the product, after being injected into the groundwater, is designed to act as a sponge in the soil to which PFAS “sticks” as PFAS-contaminated groundwater moves through the injection area.
Perhaps most notably, when it approved the injection of PlumeStop® at the Ridge Run Site, the EPA announced what amounted to a near-approval of the product: “PlumeStop® Liquid Activated Carbon is an innovative groundwater cleanup technology designed to rapidly remove and permanently degrade groundwater contaminants . Once pollutants are sorbed onto the regenerative matrix of PlumeStop®, biodegradation processes achieve complete remediation at an accelerated rate.” The EPA also stated, “Based on the information provided, we do not believe that the proposed injection will cause an adverse impact on groundwater.”
PlumeStop® was injected into the groundwater at the Ridge Run Site in April 2021. DEP has stated that “
As with all remediation treatment technologies, site-specific conditions, the design of the treatment approach and a number of other factors can affect the degree of success, both in the short and long term. Ridge Run is not the first site where PlumeStop® has been used, and other sites (as well as other products and technologies) will be closely monitored. But given the maturity of the Ridge Run Pilot test (approaching two years since injection), this site should be instructive to those focused on cleaning up PFAS-contaminated groundwater.
Disclaimer: This warning has been prepared and published for informational purposes only and is not offered, nor should it be construed as legal advice. For more information, please see the company’s full disclaimer.
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