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First Demonstrated In-Situ Treatment Solution for PFOA/PFAS

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Video Transcript

Narrator: Recent news sources have exposed an emerging threat to our communities, relating to groundwater resources. Around the U.S., communities are concerned, gathering to demand that their representatives swiftly address what some consider an imminent danger to clean drinking water.

PFAS, an acronym for a family of chemicals known as Per- and polyfluoroalkyl substances are man-made compounds with wide-spread commercial use in carpets, upholstery, nonstick surface treatments, and historically found in foaming agents used in firefighting activities. PFAS chemicals, such as perfluorooctanesulfonic acid, known as PFOS, and perflourooctanoic acid, PFOA, have come under increased scrutiny by environmental regulatory agencies due to their toxicity, persistence in the environment, and increasing prevalence as contaminants in groundwater. Many PFAS compounds are extremely stable molecules, resistant to most in-situ treatment methods. A breakthrough technology is now available that eliminates risk posed by PFAS contaminants. The innovative solution allows for the treatment of PFAS in situ without costly pumping, removing the risk to human health and the environment.

Hydrogeologist, Rick McGregor, President of InSitu Remediation Services, Ltd., Canada’s leading in-situ remediation firm, was contracted to perform an in-situ remediation of groundwater contaminated with hydrocarbons and PFAS and PFOA.

Rick: There’s a bunch of factors with respect to PFAS and PFOA. One is that it’s a new and emerging contaminant, so not much is understood about the [inaudible 00:02:03] transport of the contaminants themselves, which makes remediation targeting and designing programs a challenge. The second is, once we do understand where it is, we have to get to variable detection limits, which is another challenge. The third challenge is actually, if we are doing an in-situ remediation, is actually trying to get the reagents to the contaminants themselves, which has always been a challenge for any contaminant.

Dr. Thoreson: PFAS contamination ends up being very, very large and dilute plumes, making it very difficult to ever treat the entire plume. And so what PlumeStop offers is a way to inject activated carbon in-situ, create a barrier that’s going to allow for containment of those plumes and prevention of those plumes from magnifying.

Rick: In the case of PlumeStop, we can actually inject the PlumeStop relatively easily. It’s one of our easiest reagents to inject physically. So, we can actually get it into the ground and get very good distribution. We know that from doing numerous cores at sites and looking at the actual distribution of the PlumeStop within the subsurface itself [SP].

Narrator: In an effort to better understand the longevity of the PFAS treatment of this particular site, Dr. Grant Carey, President of Porewater Solutions and an expert in mathematical modeling and environmental forensics became involved to model the site. Using the field data from McGregor’s application and monitoring, Carey explored a number of conservative modeled scenarios calibrated to the site, which presumed ongoing secondary inputs of PFAS from infiltration, desorption, and BAT diffusion from the aquifer matrix.

Dr. Carey: So, after we inject PlumeStop, we’ve got a substantial reduction in groundwater concentrations because most of the mass moves into the activated carbon absorb phase. And that’s a key step if we’re doing modeling. We’ve really gotta make sure we do that step before we go further to evaluate the PlumeStop performance.

Narrator: To date, the most effective method for treating PFAS impacted groundwater has been to pump the groundwater out of the subsurface and filter it through activated carbon tanks.

Dr. Carey: The main benefit of PlumeStop over pump and treat is with pump and treat, there’s a lot of capital cost when you’re setting up, and you’ve got long-term operation and maintenance, so every year, you’ve gotta make sure that system’s working. And the nice thing about PlumeStop that we saw at Rick’s site is that we had one injection event, and that was enough to sustain that source control for 100 years or more.

Rick: One of the big advantages of in-situ is you target the actual area of contamination. So, you’ll be a lot more effective with your remediation reagent as well as with how you put it in the ground.

Dr. Carey: So, at Rick’s site, we know for sure that it works with PFAS and PFOA. We saw multiple monitoring events after the injection of PlumeStop. We’ve seen non-detect PFAS and PFOA at every single monitor [SP] well that we have at the site.

Rick: I’ve been personally working with Genesis [SP] probably 15, 16 years now. I’ve been fortunate to be involved in a lot of the first-time applications of the products in Canada. Overall, we’ve been very happy with the products, and we find they’re very great to work with.

Narrator: Carey’s work on modeling the efficacy of PlumeStop to treat PFAS was recently presented at the National Groundwater Association conference and at the First International PFAS Conference in Melbourne, Australia. To find out more information on PlumeStop and how this breakthrough technology can eliminate the risks associated with PFAS, contact Regenesis.