Hello and welcome everyone. My name is Dane Minke. I am the digital marketing manager here at Regenesis and LandScience. Before we get started, I have just a few administrative items to cover. Since we’re trying to keep this under an hour, today’s presentation will be conducted with the audience audio settings on mute. This will minimize unwanted background noise from the large number of participants joining us today. If the webinar or audio quality degrades, please try refreshing your browser. If that does not fix the issue, please disconnect and repeat the original login steps to rejoin the webcast. If you have a question, we encourage you to ask it using the question feature located on the webinar panel. We’ll collect your questions and do our best to answer them at the end of the presentation. If we don’t address your question within the time permitting, we’ll make an effort to follow up with you after the webinar. We are recording this webinar and a link to the recording will be emailed to you once it is available. In order to continue to sponsor events that are of value and worthy of your time, we will be sending out a brief survey following the webinar to get your feedback.

Today’s presentation will focus on regulatory actions at both the federal and state levels to address PFAS contamination. With that, I’d like to introduce our presenters for today. We’re pleased to have with us Taryn McKnight, PFAS practice leader for Eurofins Environment Testing America. Tara McKnight has 20 years of experience in the environmental testing industry, specializing in emerging contaminants and pathways of concern with a focus on PFAS and vapor intrusion assessments. She is responsible for staying abreast of the latest regulatory and scientific developments specific to PFAS while collaborating with Eurofin’s operational leadership to develop services to meet the challenges of today and in the future. She is co-chair of the NGWA subcommittee develop PFAS sampling and analysis guidance.

We’re also pleased to have with us today Dr. Paul Erickson, Director of Research and Development at Regenesis. Dr. Erickson oversees the commercialization of new environmental solutions to address complex remediation challenges. In his time with Regenesis, Dr. Erickson led the development of a number of remediation products and technologies, including petrofix and flux tracer. Dr. Erickson earned a BS degree in chemistry from Florida State University, a master’s in chemistry from the University of Minnesota, and a PhD in environmental chemistry from ETH Zurich. He is an author on over 20 peer-reviewed scientific publications, mainly in the area of environmental chemistry. All right, that concludes our introduction, so now I will hand things over to Taryn McKnight to get us started.

Okay, thank Thank you and hello everyone, welcome. Thanks for joining us. I’m gonna cover the state of the union as it relates to PFAS. This is primarily a regulatory update, but I will also touch on some scientific and research developments as well. Of course, there’s only so much we can cover in about 30 minutes, so I’ll just stick to some of the more impactful or immediate actions that are being taken, which there are plenty to keep us busy. There’s, let’s start with the big ticket items at the federal level. They’ve got some far-reaching implications. These include acts of Congress, the White House, EPA, CDC, and other various federal institutions. I’m sure many of you have already seen the EPA’s latest action plan, now titled the PFAS Strategic Roadmap. The documents are pretty easy to read, so I’m not going to regurgitate it here for you. I just want to highlight these areas where actions are already underway and to bring your attention to a few you might want to keep an eye out for.

So we have the six program areas that have a multitude of initiatives that they’re responsible for, and the date ranges for that are from 2021 to 2024. And we’ll talk about those that are already in progress or slated to occur over the course of next year. The National Defense Authorization Act, or NDAA, has become a preferred tool for passing PFAS legislation. This process has become somewhat repetitive over the past few years. Each year the House looks to pass something that they call the PFAS Action Act, and each year the Senate excludes it. But what usually makes the cut is AFFF-related, so the aqueous film-forming foam, with some provisions that do expand beyond what we traditionally think of as being DOD related. Things like the toxics release inventory requirements that came out of the 2020 NDAA would be an example of that. We also see similar topics addressed like the removal and destruction of PFAS, fluorine free foam alternatives, impacts to communities near DOD facilities, so we see a repeat of those addressed in each year of the NDAA. Most notable in 2022 was probably the moratorium on the DOD incinerating PFAS substances until the department issues implementation guidance or until the EPA publishes a final rule regarding the disposal and destruction of PFAS substances, which they are still working on.

In recent months, we’ve seen some other activities pick up. So, for example, we’ve seen some movement on the DOD auditing its procurement of items containing PFAS, things like MREs. And as outlined in the roadmap, on January 10th of this year, EPA submitted a proposed rule to designate PFOA and PFOS as hazardous substances under CERCLA. They submitted this to OMB, the Office of Management and Budget, for review. And what followed were a number of lobbies, namely for the water utilities and waste management companies and then the liquid terminals association heavily pushing for an exception, which so far the EPA has not indicated that they would be granting. The OMB completed its review and then changed the designation to economically significant. In other words, the impact is expected to be greater than $100 million annually. Now that designation triggered the requirement for the EPA to conduct a regulatory impact analysis or an RIA. Then in somewhat unexpectedly, the EPA published the proposed rule in the Federal Register without a copy of said RIA, as best I can tell. But I believe the response to that is that all the supporting documents they generated satisfy the RIA requirement.

But regardless, at that point, the clock started on the 60-day public comment period, which is coming to a close here this month. Once that effort is complete, in theory, the EPA could proceed with a final rule, which they are targeting for the summer of 2023, But I think it’s expected that there will be a significant amount of litigation that ensues, which could delay that timeline. The most significant implications of such a listing would be related to cleanup actions. By designating these as hazardous substances, EPA would have the authority to order the investigation and remediation of these chemicals, which includes cost recovery. They could reopen closed sites. And then private parties would have a cause of action for cost recovery. And also, PFOA and PFOS would be included in the scope of Phase 1s in order to satisfy the All Appropriate Inquiries Rule. Additionally, this designation could have some regulatory ripple effects since many states and some other federal programs use the circle of hazardous substance lists as a basis for state-regulated compounds.

And then something else to keep an eye out for could be litigation brought by those drinking water and wastewater utilities seeking to recover costs from the PRPs for those significant long-term costs that they’re likely going to be facing. And then in addition, EPA is developing an advanced notice of proposed rulemaking to seek public input on whether to designate other PFAS. According to the roadmap, they may request input regarding the potential hazardous substance designation for precursors to PFAS, additional PFAS groups or subgroups of PFAS. So this is certainly not going to be the end of this topic. And then October of last year, in a response to a petition from the Governor of New Mexico, the EPA announced plans to initiate a rulemaking process to add certain PFAS chemicals as hazardous constituents under RCRA, the Resource Conservation Recovery Act. Now, this would include PFOA, PFOS, PFBS, and GenX. Those chemicals listed would be subject to corrective action at hazardous waste treatment, storage, and disposal facilities.

Once they’re listed as RCRA hazardous waste, the waste is also considered a hazardous substance under CIRCLA, so I guess we’ll just have to wait and see which one transpires first, although we haven’t seen much movement on the RCRA designation. And if these were to be listed as hazardous air pollutants, which in the strategic roadmap, they indicated that is something they’re evaluating, that would also automatically list them as hazardous substances under SOAR cloud. So lots of pathways here to these designations that have some very far-reaching implications on cleanup and liability. Now, most of our regulatory efforts to establish limits for PFAS include not only occurrence data, like what we obtained from the Unregulated Contaminants Monitoring Rule or UCMR, but also toxicity data. And to that end, the EPA continues to chip away at toxicity assessments for additional PFAS.

After a little bit of back and forth, we ended up with a final tox assessment for PFBS in April of last year, with a newly established health advisory limit of 2 ,000 parts per trillion as of this summer. PFBS is a replacement for a related chemical, PFOS. And then later in the year, the EPA published the final report for Gen X and in an interesting turn of events, EPA’s final chronic reference dose, the RFD for Gen X, was lower than the 2016 RFDs for PFOA and PFOS, which equated to a health advisory of 10 parts per trillion. Gen X is a replacement for PFOA. That said, the EPA revisited the toxicity information for PFOA and PFOS, and we’ll talk about that in just a moment. So PFBA is undergoing final agency review right now. It should be published by Q1 of next year. PFH XA is also in the final stages with peer review being completed, and they should be publishing in Q1 of next year as well. Others on the list for assessment include PFH excess, PFNA and PFDA. So, you know, just a handful of compounds in this world of hundreds or thousands or millions of potential compounds that we’re concerned about.

As I mentioned, the EPA revisited their health assessment for PFOA and PFOS and published revised interim lifetime health advisory limits for these two compounds. The new limits are now several orders of magnitude lower than previously listed. The reason these are interim is because the EPA is in the process of using that updated data to establish an enforceable national primary drinking water limit, which they estimate proposing before the end of this year. The proposed drinking water standard, though, will have to consider what is technically achievable in terms of detection as well as cleanup and the economics of what is feasible. So those future MCLs for PFOA and PFAS are expected to still be in that low part per trillion range as opposed to the part per quadrillion range that the interim health advisory limits are currently sitting at. Currently, the EPA has no limits for PFAS in industrial wastewater discharge to public sewage treatment plants or directly to surface waters.

However, in September of last year, the EPA released preliminary affluent guidelines program plan 15, where the agency stated that it will establish limits for PFAS and wastewater, specifically released from PFAS producers in the organic chemical plastics and synthetic fiber industries. So this would include the big guns like 3M and Chemours. The EPA is getting ready to begin this monitoring effort this fall and will propose affluent limits by the summer of next year. In addition, the EPA said it will also set similar discharge limits for chromium electroplating facilities that use and release PFAS, and the plan includes the initiation of detailed studies of PFAS discharges from landfills and textile categories. The EPA issued a memorandum on April 28th of this year addressing EPA’s revised guidance for addressing PFAS in NPDES permits, or N-P-D-E-S, where EPA is the permit issuer and control authority. So the EPA intends to require monitoring for PFAS under federally issued permits.

Monitoring will require the inclusion of the 40 compounds that are listed in EPA’s draft method 1633, but interestingly enough, does not require use of the draft 1633 method as it is not yet a promulgated method. So equivalent methods are still permissible. They also mentioned the availability of draft method 1621. This is for the analysis of adsorbable organic flooring, and they say if appropriate, but it is our understanding that the EPA intends to use AOF broadly in their investigation efforts. They point out that this program would enable the EPA to obtain comprehensive information on the sources and quantities of PFAS discharges, and then, of course, those data would be used to inform the agency’s Affluent Limitation Guideline actions. Maybe of most interest to you folks would be the statement that the EPA plans to issue additional guidance to state permit writers and local pretreatment authorities on how to address PFAS. And those efforts are already underway.

Now in accordance with obligations under the 2020 NDAA, EPA has proposed reporting and recordkeeping requirements for PFAS under the Toxic Substances Control Act, or TOSCA. This would require those who have manufactured or imported PFAS in any year since January 2011 to report information regarding uses, production volumes by category, byproducts, environmental and health effects, worker exposure, and disposal. The public comment period ended last September, and in response to public comments, EPA stated that they are interested in convening a small business advocacy review panel on the rulemaking. you can imagine what the perceived impact would be on small businesses for complying with this. So that panel would include federal representatives from the Small Business Administration, OMB, and EPA. According to the agency though, if this rule were to be finalized, the proposal would provide the EPA with comprehensive data on more than a thousand PFAS, so really a leap forward in our understanding about these chemicals and their use in our commerce. And then the proposed deadline for reporting PFAS data to EPA would be one year following the effective date of the final rule. So not much time to comply with that one.

If you’re not familiar with the Emergency Planning and Community Rights to Know Act, there is a Toxics Release Inventory Provision, or TRI, that tracks the management of certain toxic chemicals that may pose a threat to human health and the environment. So U.S. facilities across industry sectors have to report annually how much of each chemical is released to the environment, and a release is defined as any of these chemicals that’s emitted to the water, land, including land disposal, or to the air. And as established by the NDAA, in the first year, 174 PFAS compounds were reportable with threshold of 100 pounds per year for each of the listed PFAS. However, there were certain exemptions or exclusions in place like the de minimis rule, which significantly has limited the amount of data that EPA has received for these chemicals. And so the EPA has stated that they intend to address those exemptions with a future rulemaking. And then switching gears a little bit here, And now we’re going to look at all the emerging product legislation.

This gives you some idea of the scope of state legislative efforts to enact bans, prohibitions, or some kind of restriction on the manufacturer’s sale, distribution, or use of PFAS-containing products. A lot of the bills use the same language. So for example, many of them use the same definition of what constitutes a PFAS, defining it as any member of the class of fluorinated organic chemicals containing at least one fully fluorinated carbon atom. This means that shorter chain PFAS would not be considered safer alternatives here. And we’ll talk a little more about the challenges around demonstrating compliance with such a law in a moment. They also use the same caveat of the ban applying to intentionally added PFAS, but none of them go on to define what limit constitutes intentionally added. So some go as far as to say intentionally added and present in any amount, which is the case in states like Vermont. And in the rare case of California, they say intentionally added or above 100 parts per million.

When it comes to AFFF, the Class B firefighting foam, there are typically two approaches, either a complete ban on PFAS-containing foam or a restriction on using it for emergency response only and the capture and disposal of the foam after the incident. These laws range with effective dates as early as right now to several years out. However, there’s something interesting to note about a few of them. The effective date does have a caveat. It only goes into effect provided a safe alternative has been identified, which in most cases it has not yet. Now let’s talk about what the compliance side of this looks like. It’s important to understand that the laws as written use pretty simple and broad statements. In a matter of a few lines, almost all of the laws simply state, no party shall manufacture, sell or distribute, insert product type here, containing intentionally added PFAS. So now it’s up to the regulatory agencies to determine how they’ll enforce such laws and how they will address some of the nuances or technical challenges that inevitably arise when we try to implement these practices.

Some states stipulate a requirement for providing a certificate of compliance, but even with that, what will the certificate reference? Now this is where the rubber hits the road. So if you need to certify that your product does not contain any intentionally added PFAS, how will you go about this? Will you be able to rely on information contained in safety data sheets? Remember that PFAS are not yet classified as hazardous substances, so they’re not required to be listed on an SDS. Will this require analytical data? If so, what will you test for? There are thousands of PFAS chemicals in the world, most of which there are no analytical methods for. Will you test for total flooring or total organic flooring as a measurement of all PFAS, and if so, at what limit? So what limit the regulators deem is indicative of intentionally added versus unintentional has yet to be defined. And these just appear to be some of the questions that state regulators are trying to sort out for themselves and that we will have to navigate as we move forward with trying to comply with these litany of laws.

Now I’m gonna focus on drinking water since this is such a huge topic with a lot of activity around it and importance of course. For those of you who are not familiar with the Safe Drinking Water Act, this is what part of the process looks like for setting an MCL, that maximum contaminant level. And right now the EPA is in the proposed rule phase of this process for PFOA and PFOS only, which as I mentioned, they are targeting for the end of this year. Once it’s proposed, there will be a public comment period and final agency reviews before the rule can be adopted, which they are targeting for the end of 2023. And then in an interesting turn of events, we’re starting this process all over again with the next round of the UCMR. So the next UCMR process is already underway. The final rule was adopted in December of last year, which includes 29 PFAS compounds. Monitoring will occur between 2023 and 2025. And there’s a number of really interesting points to note about this.

This is the first time in UC Mark history that they’ve looked at the same chemicals twice. Due to a recent change to the Safe Drinking Water Act, this monitoring will now affect public water systems serving greater than 3 ,300 customers as opposed to the previous 10 ,000 customer threshold. The reporting limits for PFAS will be much lower than they were during UCMR 3. And this effort will require two analytical methods to capture the full target list of PFAS compounds. So let’s take a look at what those compounds are. We see a repeat of the six compounds from UCMR 3, also the inclusion of a few replacement chemicals and the shorter chain chemicals that were added to method 533, all for a total of 29 unique PFAS across the two methods. I also want to highlight for you the required reporting limits for the UCMR-5, in particular for PFOA and PFOS, where we currently have HALs in the part per quadrillion range. So UCMR-5 requires PFOA and PFAS to be reported down to four parts per trillion.

Now, although this is purely speculation on my part, I think it stands to reason that this may very well become the basis for a future drinking water standard, since it, too, has to take into consideration what is technically achievable. I’d like to highlight just a few of the activities on the research side of things to show kind of the breadth of potential impacts from PFAS. Of course, all the research would be an entire day of talks, so I’m just going to highlight a few examples here. The CDC has been hard at work for many years now conducting a number of studies related to exposure and health effects of PFAS. The CDC leads what’s called the multi-site study with the goal to learn more about the relationship between PFAS exposure from AFFF-impacted sites and health outcomes among differing populations. They also conduct the National Health and Nutrition Examination Survey, or NHANES. It’s a biomonitoring effort that’s conducted every two years, although that’s gotten a little screwed up with the pandemic. And among other chemicals of concern, the CDC has begun testing human serum for 16 PFAS compounds designed to provide nationally representative information for the general U.S. population. And as directed by, I believe it was the NDAA, the CDC also investigated potential sources of PFAS exposure other than from drinking water. This included things like indoor air and dust, and we’re certainly looking forward to seeing that final report as soon as it gets published.

Lastly, the CDC sponsored the National Academies to generate a report, which they published earlier this year, with recommendations for the agency to update its clinical guidance to advise clinicians to offer PFAS blood testing to people who are likely to have a history of elevated exposure, so folks that may have an occupational exposure or those who live in an area with known contamination. The EPA is conducting a study assessing the potential for PFAS to pose a vapor intrusion risk. We are also waiting for the final report on this assessment of subsurface migration potential of PFAS into buildings and residences. And then the EPA continues to evaluate and investigate the matter of PICS. That stands for Products of Incomplete Combustion. This would be from destructive technologies like thermal incineration. This ties into the EPA’s goal from the roadmap to collect data to inform the 2023 guidance on destroying and disposing of certain PFAS.

Right now, they’re very much focused on kind of the ultra-short-chain PFAS and developing a method to be able to capture those from things like source air. One area where there seems to be a little bit of disconnect between state and federal priorities is on biosolids. The PFAS roadmap has the following listed. The EPA expects to complete a risk assessment of PFAS and biosolids by winter of 2024 to determine if regulations are needed and this would only apply to PFOA and PFOS. States are struggling right now with whether to restrict land application of biosolids, what limits are appropriate to use, and if biosolids are in fact impacting the food supply, which leads us to the next topic. This is another area where there seems to be a little bit of a disconnect with what the FDA’s diet study reveals and what individual site assessments are indicating. So to understand the potential dietary exposure to PFAS from food, the FDA includes PFAS testing in the total diet study and in three rounds of testing, the FDA has found very little, if anything, and so they’ve concluded there’s no indication that the food supply is impacted by PFAS contamination.

In though, these studies are being reported against the backdrop of report after report on site-specific contamination in the food supply from sites that are known or thought to be impacted by PFAS contamination. I’ve shared just a few of the headlines here over the past year or so that are related to this topic and also as another result of the NDAA, the DOD had to inform farms of potential impacts to their water supply, which appears to have included more than 2 ,100 farms. Now what impacts that contamination does or doesn’t have on the food from those farms is I think yet to be determined. So no smoking gun yet, but I think definitely some red flags that no doubt are gonna continue to be investigated further. And of course we have the litany of states passing legislation banning the use of PFAS in food contact materials, I think we’re up to about 31 now, which would also speak to the concern that this is getting into the food we consume. The FDA has published a request for information, they published it this summer, to obtain data and information on the use of fluorinated polyethylene containers for food contact applications.

The FDA stated that it’s seeking scientific data and information on current uses, consumer dietary exposure that may result from those uses, and the safety of certain PFAS that may migrate from these containers. And there is some literature on the leaching of fluorinated containers into food products. An example of this is a recent study published in the Journal of Agriculture and Food Chemistry that looked at food products sold in China. The Chinese researchers found that containers for ice cream, instant noodles, and bubble tea that are made with PFAS chemicals do leach the chemicals into the product. And EPA has conducted some kind of similar assessments here in the US, although not related to food, but related to pesticides and the potential for those fluorinated containers to leach into the pesticides products contained within.

So lastly, I’m going to update you on some of the method development efforts for measuring PFAS in the environment. EPA released a copy of draft method 1633 last winter. This method was developed for PFAS analysis in non-potable water, solids, tissues, biosolids, and landfill leachate. This is a targeted analysis for 40 PFAS compounds, and fundamentally it aligns with the user-defined methods that have been the basis for PFAS testing for the last two decades, so we do expect a degree of comparability in the data sets as we transition from one method to the other. This method is currently undergoing a multi-lab validation effort as part of the rulemaking process. This effort began at the beginning of this year, and it’s looking like it’s probably going to continue into 2023. There has been somewhat of a fractured response to utilization of this method so far. The DOD immediately adopted the draft method as written and required use of it on all new task orders after January 1st of this year. Then the EPA Office of Water immediately endorsed use of the draft method for wastewater monitoring efforts in particular.

So far, Colorado appears to be the only state with a statewide wastewater program that has required use of the draft method. Most states will not offer accreditation for draft methods, so they’re still using the user-defined methods. We did, though, see New York transition just this week to using the draft method, regardless of accreditation status. And then at the T &I conference in August, the EPA Office of Water Representatives made an announcement that the EPA intends to proceed with finalizing the non-potable water portion of this method and publishing it as final prior to the completion of the other matrices. We’re expecting this effort to be fast-tracked before the end of this year, given the priority of addressing PFAS and wastewater. They also stated that once the remaining matrices have been completed through that multi-lab validation process, they’ll add those as addendums to the method.

An important component of the method development efforts is the target analyte list. On the left here you can see the 40 compounds that are part of the draft method 1633. On the right include additional compounds that are commercially available using existing user defined methods like 537 modified. So even once draft 1633 is finalized, if you’re looking for a more expansive list of compounds, you’ll need to use these other methods. But even at around 80 PFAS, we’re still a far cry from the hundreds or thousands that may be present or pertinent to our investigations, thus the interest in a proxy tool for total PFAS measurements. So EPA has recently released another draft method, this time for AOF, the adsorbable organic fluorine, and this is draft method 1621. This method is a bit further behind Draft 1633, as it has not officially begun the multi-lab validation, but the effort to secure labs and procure samples to send to them is underway. But remember what I pointed out at the beginning, that the EPA has noted they intend to begin using it in their wastewater monitoring efforts to gather data that is going to help inform those future affluent limitation guidelines, and I’ll show you the reason why, perhaps.

So, at Eurofins, we conducted an internal small-scale study on PFAS and wastewater. We applied all the analytical tools we had at our disposal to see what measure of utility there is across the different methods for this matrix. This is a snapshot of the results from one of the sites, but it’s pretty reflective of what we found across all the sites. We see a handful of compounds detected from the draft 1633 list, and we see a few more that would not be captured by the new method. But more importantly, nothing is detected above 35 parts per trillion, so pretty low levels in this sample. However, when we run the AOF analysis, we see a very different picture. We see over 1 ,000 parts per trillion of organic flooring content. This is one of the reasons why we suspect EPA intends to include AOF in their monitoring efforts because that targeted list of 40 compounds from draft 1633 is not likely to capture all that is really going on in these samples. And then kind of on that note, with the PFAS class of chemicals, we’re largely operating in a world of unknowns. And with that, the ability to test for unknowns, otherwise known as a non-targeted analysis, has become more attractive.

It’s an important thing to understand, though, that this is a very sophisticated tool, not only from the standpoint of generating the data, but also from the standpoint of interpreting the data. These are the type of data that might be used in a forensics investigation. These data are not fully quantifiable in the way that targeted analyses are, because we don’t have standards for these compounds. This is really more about identification than reporting an accurate concentration. Also, sensitivity is a limitation. We’re not going to see anything at less than around one part per billion, and even then our confidence levels may be impacted at anything less than around 10 parts per billion. So to date, this is really more a tool for when there’s known contamination or a source rather than those ultra-trace levels of PFAS. Another limitation has been our ability to communicate the results with a consistent approach. So this is a recent area of development.

You might be familiar with the Shimansky Scale. This paper expanded upon that scale and set out to harmonize the approach for communicating PFAS identifications when using high-res mass spec. Here, they’ve created a confidence scale along with identification criteria specific to suspect screening or non-target analysis. And so, the criteria highlighted in blue are required for PFAS identification at a given confidence level. At least one of the criteria highlighted in gray must be met at the given confidence level. So, this was really an important step forward with this type of technology for people to able to interpret their results and understand what kind of confidence levels we have in those identifications. And with that, we are at the end of my talk. So now I’m going to hand you over to Dr. Paul Erickson with Regenesis.

Great. Thank you, Taryn. So Taryn gave us a great overview into the regulatory efforts surrounding PFAS and what doing today to kind of work towards reducing exposure. She talked about the research going into exposures, both from food and environmental, and as well as the analytical methods to inform on both of these. And so what I’d like to do is switch gears a little bit and talk about the methods that we have at Regenesis that we use to address PFAS impacts in situ. So, at Regenesis, one of the ways that we can manage PFAS once it’s reached the groundwater is through the emplacement of permeable absorptive barriers. So, we can use a product known as Plum Stop, and we can emplace barriers in the subsurface that allow PFAS plumes, once they’ve already been generated, or are impacting groundwater. As the contaminated groundwater moves through these areas that we treat with PFAS, you can strip out your contaminants, and you’re left with clean water migrating down gradient. And so this can be done up close to source areas.

We can use them, we can use plume stop in a series of barriers as shown here on the right. And what I’d like to do is I’ll first kind of show you or talk through what we see as the paradigm for this being a viable form of remediation to manage this problem, and give you a little window into the parameters that we need to understand in order to successfully implement these types of treatments. And so first I’ll tell you a little bit more about what PlumeStop is. So it’s a form of colloidal activated carbon. So it’s activated carbon that’s been milled down to the size of one to two microns in diameter, and it’s formulated so that you can distribute it easily and sit you. And so what that allows us to do build these permeable barriers we talked about before and any contamination that’s then migrating through, it gets adsorbed onto our activated carbon that has been distributed into the subsurface. And so the mode of action for remediation when we’re talking about PFAS is it’s a dynamic adsorption.

So the contaminants in the case of PFAS aren’t destroyed, but rather we’re greatly reducing how quickly they’re moving through the subsurface through this dynamic adsorption. So what we like to talk about this is in terms of retardation factors that we can achieve with colloidal carbon treatment. So up to 10 ,000. And that allows us to get sequestration of our PFAS that are moving through on the order of decades. So what is this 10 ,000 retardation factor that I’m referring to? So it refers to how quickly your contaminants are moving relative to the groundwater. So if you’ve got groundwater that’s moving at some rate and a contaminant that’s moving at the same rate, you would have a RF of one. And so if your contaminant is then moving at half the rate of your groundwater, we would say it’s got an RF of two and so on and so forth. So an RF of 10, your contaminants move at 10th of the rate of your groundwater. So 10 ,000, you can see, you know, this is, you’re looking at decades slower migration of your contaminants.

And this is then what we’re talking about when we say the sequestration of our contaminants. And so how this then fits with remediation is, I’ll kind of explain it over this next slide, it’s this idea of enhanced attenuation. So we’re adding an adsorbent to the subsurface that then allows for, you know, we’re storing these contaminants outside of the media that we really are concerned about, which is groundwater in the case of in situ treatments. And so similar to monitor to natural attenuation, we’re kind of setting the stage for these processes to help strip out the contamination and keep them out of the areas that are concerning to us. So if we kind of look at how you manage a hazard or what the hazard means to us in the remediation world, so you have to have both exposure and risk. And so the idea is that if we can limit exposure by putting a sorbent in place that will then remove our contamination, that then stops the hazard because you no longer have exposure, despite the fact that we understand that there are risks to these contaminants.

And this is in line with the treatment of other recalcitrant and non-degrading contaminants, such as metals. And so in line with the same way of thinking, others are sort of helping develop this idea and really set the stage for, And given the scale of PFAS contamination in the environment, there’s going to be several different means and methods by which that we have – are going to rely on for remediation. And we feel that this is one viable one that we have today that we can use and put into practice now. One other consideration for the use of plume stop in situ is the sustainability. So pump and treat systems, just as one example, require – it’s a rather energy resource intensive means of remediation and passive methods, including the use of plume stop for in situ groundwater barriers. This greatly reduces the environmental impact, greenhouse gas emission impact. You can see some of these other parameters that I’ve got listed here. This data came out of a life cycle analysis that was done in part with Ramble Consulting and the Danish EPA. And they put out a study just recently that was evaluating a plume stop pilot treatment that they had done and basically looked at how this would stack up had it been a pump and treat setup or system for these various parameters.

So you can see energy use is substantially reduced. There’s no active pumping. There’s no infrastructure really that’s required for the use of plume stop versus pump and treat, which does require it. Hazardous waste, disposal costs or just generation of hazardous waste in general. You don’t have any of that with the use of an in-situ passive system. And so while this particular life cycle analysis was done for chlorinated site, the story would be very similar if we were to consider this as a treatment for PFAS. So what I’ll do now is just kind of walk you through the different pieces that we need in order to put together a successful in-situ treatment of PFAS or any contaminant, for that matter, with plume stop. And so what we need is kind of listed across the top here. So I’ll walk through each of these quickly. So first is we have to understand what our absorptive capacity is for not only the contaminants that we’re concerned about treating.

So PFAS in this case, this is PFOA. So we’ll work to collect isotherms, which give us a measure of understanding of how the contaminants that we’re concerned about are going to adsorb onto our plume stop carbon, our colloidal carbon. We also have to know this information about other contaminants that may be present, non-target contaminants that is, because the carbon it’s going to see whatever is present in the groundwater regardless of if you’re after treating it or not. So after the sorptive capacity is kind of understood, the next important piece here is the contaminant mass flux. So we have to understand the heterogeneity of our system, the aquifer that we’re working in, and both in terms of the soil types that are present, and also where our groundwater is moving on an area that we’re considering working. And so the product of our contaminant concentrations in our groundwater and our groundwater velocity or how fast it’s moving, that gives us our contaminant mass flux. And so really that’s what our barrier is treating.

Our barrier is treating a mass flux. So we need to understand where’s the mass moving, the contaminant mass, so that we can properly dose and imply our plume stop or other amendments into the subsurface in the right locations and ensure that we get performance on the long run. And then the last piece of the puzzle is the aquifer specifics on a site. So understanding what the field implementation needs to look like, so point spacing, how fast or how readily the fluids will be accepted when we do the injection work and a lot of this work can be done or is done rather on projects kind of at the early stages so we have a design verification process that goes in and really helps us to make sure that we’re going to get nice even covered of our amendments across the areas that are going to matter the most to ensure a proper performance of our sites over the long run. So each piece of these of the puzzle here is all put together and this is what we use when we’re putting together a plume stop design, and the first two, the absorptive capacity and our mass flux, those are fed into models.

So we have the ability to interpret, you know, what do we need to do dosing-wise in order to get good performance on kind of on the development stage? And then the design side of things, you know, where does our point spacing need to look like? You know, that can be done in the field, but the combination of those is what then leads to a proper emplacement of our barrier. So you see here, you’ve got a row of points here that would represent your injection points and that’s intercepting your contaminant that’s moving off site from a spill or another source area. So with this last slide that I have here, I’d just like to give you an idea of the progress and the scale and the scope of the projects that we’ve done here at Regenesis to treat PFAS to date. And so along the X axis, you see it’s just time. So the number of projects that we’ve done date back to 2016 in terms of treating PFAS. On the y-axis, I’ve got the sum of the PFOS and the PFOA concentrations that are present on these different places that we’ve worked. And you can see, you know, there’s an upper limit.

We typically are, and our sweet spot I’d say is beneath 100 parts per billion for these particular contaminants. And the, you know, other things you need to know to interpret this slide would be the size of the dots, which that represents the scale of the project itself, or the price tag. So this largest one here would be a $1.5 million project. And then the color is the last thing, really, that I’ll point out. And so the dark green circles represent 95% reductions in contaminant concentrations within 90 days. And the red one being 75, less than 75%. So the big takeaways from this plot are that, you know, we generally are seeing more projects to treat PFAS. Our performance is typically on par with what we would expect. You know, we’re getting, you know, drastic if not complete reductions in PFOA, PFAS, or the other target contaminants that we’ve been asked to treat. And there are in some cases at the pilot level, which is marked by these circles that are fully in case there’s a border on them, we do get under performance initially in some cases.

And what that does is that tells us that there are, I guess, knowledge gaps in either the implementation that we need to account for. And in these cases, we are able to do that. We can go back in, you know, after initial implementation of a project and make sure that we’re getting proper coverage where we need to. And as you can see, we’ve had instances now where smaller scale projects have led to full-scale implementations of these larger projects. And so, again, that trend continues and we expect to see the momentum keep picking up here in the coming years. And lastly, I’ll just show you an overview of the places that we’ve worked, both on the completed projects and then through the scheduled applications and design. We’ve got more, even since this got put together, that have gone in the ground. And so, if this is something that you think would be of utility on your site, you know, get in touch with us. And we’d love to work through your problems with you. And with that, I’d be happy to take any questions and also open the floor up again with Taryn. All right.

Thank you very much, Paul. As Paul mentioned, that does conclude the formal section of our presentation.