Hello and welcome everyone. My name is Dane Menke. I am the Digital Marketing Manager here at Regenesis and Land Science. 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 not fix the issue, please disconnect and repeat the original 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 time, we will be sending out a brief survey following the webinar to get your feedback.

Today’s presentation is the first in a two-part series on risk and liability, and we’ll focus on PFAS mitigation and managing liabilities. With that, I’d like to introduce our presenters for today. We are pleased to have with us Hilary Robinson, Emerging Contaminants Lead for RPS Ocean Science. Hilary Robinson excels in the evaluation of chemical fate and transport processes for exposure reconstruction and spill modeling, particularly related to large-scale chemical releases with multimedia impacts and emerging contaminants. Using these skills, she provides support to clients wishing to evaluate matters related to ecological, occupational, and public health. We’re also pleased to have with us today Eric Leitz, Director for RPS Legacy Site Services. Eric Leitz has almost 25 years of experience in the environmental field, overseeing site investigation and remediation of soil, soil gas, and groundwater. Eric has spent several years working with clients on sites with known or potential emerging contaminants concerns, such as 1 ,4-dioxane and more recently PFAS. As part of that experience, he has supported numerous clients by providing liability estimates related to acquisitions of facilities with operations with suspected or known emerging contaminant concerns.

We’re also pleased to have with us today Ryan Moore, senior technical manager and PFAS program manager at Regenesis. Ryan Moore has over 20 years of experience as an environmental project manager and laboratory account executive relating to multimedia contamination sites throughout the U.S. His experience has focused on site investigations of soil and groundwater contamination, corrective action evaluations, operation and maintenance of remediation systems, large soil removal remedial projects, in situ groundwater and soil treatment, vapor intrusion assessments, environmental laboratory operations such as QAQC evaluations, data interpretations, and business development. All right, so that concludes our introduction, and now I will hand things over to Hillary Robinson to get us started.

Thank you for tuning in to hear from myself and my colleague, Eric, who will be talking today on assessing PFAS risk and liability at a site and how to self-evaluate and best mitigate those risks while we’re in this period of regulatory uncertainty and rapid change in PFAS. Here’s a quick refresher on our company, RPS. It’s a global consulting firm headquartered out of the UK and Eric and I are located in our Chicago and Rhode Island offices working around the country on site investigation and spill risk assessment. We’ll be speaking today from the perspective of someone working at or on behalf of this facility. This biography here was pretty well summarized. Thank you, Dane. Someone who is at a facility might be wondering, did we use PFAS in the past? Is there PFAS in our product, our discharges, our soil? So hopefully we can use our experience with these types of assessments to provide best practices for answering those questions, both in terms of limiting risk and exposure potential and and limiting potential costs from that.

To give you a sense of RPS’s activity on PFAS, we have more classic roles in site surveying, investigation, transactional advising, as is the focus here, but we also have strong programs in the UK to lab analyze PFAS and unique media. In Australia, we’re managing the Department of Defense PFAS investigation at over, I think, 28 bases now in the Australian Department of Defense. And in my state of Rhode Island here, we’re focused on modeling PFAS and AFFF in large water bodies and lakes and oceans. I don’t have a lot of introduction here on PFAS, but I do want us to remember what makes them the issue that they are. PFAS are only manmade. They’ve been around since the 1930s, but they’ve changed dramatically in terms of the specific compounds produced are released as byproducts or contaminants. Because they have such strong carbon-fluorine bonds, they persist in the environment. They were in the name Forever Chemicals. I like this description here of perfluoroalkyl acids as similar to detergent, but with fluorine atoms instead of hydrogen.

So on one end, the left side here, you have fluorine atoms that don’t stick to anything. They are resistant to grease, water stains, chemicals, heat, fire. They make a really useful product. on the other end, they’re hydrophilic, friendly to water, and therefore can be highly mobile in water and move through the environment. The longer chain compounds, that is those with more carbons and associated fluorines, generally are more bio accumulative and have greater toxicity, which is why PFOA, PFOA, and PFOS are eight carbon compounds with EPA’s lowest health-based exposure guidance levels, which are essentially zero in the last iteration. So, my first question is looking at a facility internally, even if you don’t know what’s being used is, are we creating something that is repellent to everything? Does anything here look like a PFAS usage? And did we ever use or even still use the longer chain compounds that have particularly essential functions? Or have we ever imported them from international sources?

I’m going to pause for a second and we’ll try and stick an image in your brain to cement this concept. So imagine the little fluorines lining these compounds, each one with an entirely non-sticky end. So if you coat a pan or a jacket or a popcorn bag or a roaring hot fire with foam, you’ve created a non-stick surface. The other ends of the compounds bind the coating to the surface. If the coating becomes degraded or detached, then those compounds can float around in the water with still that non-stick end of them that moves through the environment. One important term to know is precursors. These are the more complex compounds, though still technically PFAS by definition. They don’t have the same degree of environmental and health concerns. However, they can degrade, oxidize, or transform in the environment to form the proforoalkyl acids of greater concern.

Another important understanding is the shorter chain compounds have only recently been used intentionally and at larger volumes in products. So PFBS, GenX, for example, were substituted to replace longer chain PFAS, yet still have potential for environmental and health risks that are leading now to a newer phase of regulation and guidance setting. Because PFAS are useful for water resistance, bioresistance, and coatings, they have many industrial usages. PFOA and PFOS, PFOS, and their replacements have been used in coatings for carpets, clothing, upholstery, paper products, such as resistant cardboards and popcorn bags, metal plating, surfactants, semiconductors. One of the biggest usages that involves direct release to water rather than just being a byproduct in manufacturing has been AFFF, aqueous film forming foam, which is used for fire suppression and firefighting, especially airports and military facilities.

Another source of PFAS in the environment is the waste from these usages, which can to landfills or to wastewater treatment plants where PFAS accumulate in sludge and can indirectly enter the environment. Some PFAS are not captured by treatment and go into water and others accumulate in biosolids that are spread over agricultural sites as fertilizer. The business of figuring out where PFAS that has been found in the environment is coming from therefore very complex. So as mentioned the goal of this presentation is to walk through a series of and lessons learned that you might consider when determining the risks from PFAS posed at a site and how those risks and liabilities could be managed. It’s important to remember how hard it is to know if PFAS is present or used at a site. It’s a catchall term that can capture many things, many compounds. No MSDS safety data sheet is going to say PFAS on it. It may not even list specific compounds.

So you want to look for the non-stickiness. You want to look for fluorine, even that floor phrase, and then follow the trail to understand what compounds with fluorine exist, if they could be PFAS. There should be more data available soon with the new TASCA reporting rule to understand what’s being produced by manufacturers as well as imported. There are multi-industry studies that are useful with helpful research on typical PFAS ingredients. There are some state-based resources like the Massachusetts Tura. That’s helping companies determine if they are using products with PFAS and kind of the free service contacting suppliers to get details that are not provided on the SDSs due to confidential business information. So I would expect more surveys and requests to be passed around as everyone tries to get a better picture. Once you have supplier information in hand or historical documents about the processes that may have contained PFAS, the next question would be, does the timeline fit what you’re seeing? PFOS, PFOA, and PTFE have been in use a long time.

Fluorotelemers, which are the predominant compounds in current firefighting foams, are more popular now and don’t contain the longer chain perfluoroalkyl acids as intentional major ingredients. Another way of thinking about this is putting together a classic source pathway receptor analysis to see if you can connect the dots to PFAS being detected in the local environment. Chemical fingerprinting is definitely possible with PFAS, but it’s not simple. And I believe it really needs a weight of evidence supporting it that shows the historical or current use matching that fingerprinting, a matching industry usage that makes sense of why you would use those products, a matching timeline to the types of compounds being produced, and when they would have entered the environment and a pathway of release to the environment via direct or indirect waste. Plus, you need to consider other sources of PFAS in the environment, essentially the unnatural background which we’re realizing is, you know, very prevalent in many larger water bodies and groundwater throughout the environment.

There’s an increasing trend in attention and public focus to facilities that were previously ignored, especially as people try to connect the dots to contaminated sites. Various states and organizations are rapidly increasing investigations and spending lots of resources to find PFAS sources. The national UCMR sampling for unregulated contaminants is being expanded for new PFAS compounds. Statewide investigative hunts are ongoing to find both contaminated drinking water and the linked potential sources. When a wastewater treatment plant, for example, realizes that it has PFAS and it’s influent and it’s not sufficiently treating that PFAS, they will look upstream to determine the source and promote source reduction or industrial pretreatment in their customers. Many states are implementing routine monitoring, as well as some federal level initiatives to sample and identify PFAS discharges before they end up in drinking water.

New resources such as these maps from the environmental working group above and a recent PFAS project lab study are publicly available and searchable online to flag thousands of facilities in the U.S. that are the type of industry or discharger that could have or had released PFAS. I’m not going to mention the caveats here, but it’s worth noting that these are just suspected or presumptive sources rather than known, you know, proven or sampled sources. And these maps don’t provide a detailed understanding of the pathways into the environment that also need to exist to cause contamination. But a facility that’s on these maps could expect near-term needs for PFAS research and or investigation. Here’s an example on the right of what those statewide investigations look like. In this case, I pulled a list from Florida. Investigations are often performed by overlaying maps of contamination and suspect facilities and then sending out sampling teams to confirm when you see contamination and facilities in proximity to each other.

The standouts for me on this list, beyond the more unsurprising industries and firefighting training facilities, include looking at areas where AFFF may have been applied or spilled. EPA has actually started compiling information from the National Response Center, and data resources like ERAS and EDR have started hoovering in that information to be able to do site searches. Also, I noted the bulk storage tank facilities, shipyards, and cruise terminals listed here They’re listed because fires at those types of locations have greater urgency and need for AFFF and therefore may not have transitioned or had greater need for the legacy AFFF foams with longer chain compounds. Most facilities have a plan for what to do in case of a fire, but I think it’s an important topic to consider how a facility uses and stores foam in the inventive of a fire. Regulation is coming into place dictating how to manage, store, and use AFFF. And there are already quite a few resources available to target best management practices, particularly from the ITRC has a really, I think, great fact sheet with a lot of ideas and recommendations.

There’s also state-sponsored buyback and disposal and support programs to help deal with kind of existing AFFF and management plans. There are several ongoing projects to tackle the tough transition to fluorine-free alternatives. You can’t just hook up a new foam into your system and be on your way because the levels of concern for PFAS discharge are so low. Typical cleaning and flushing of lines may not be sufficient. On the other hand, just replacing components is expensive, so you need to target those components that are hardest to clean while still managing the waste generated and ensuring sampling is accurate enough to even confirm you’ve achieved what’s needed. Therefore, it’s worth considering the protocols in place for a fire. When do you just let something burn down instead of putting up? Can you use flooring free foam for a certain type of fire that doesn’t require a triple F? If your facility has mobile resources, trains, vehicles, what would a local fire department do if they helped with an incident? Do you have an agreement in place with them? These are the types of questions that can be considered now without having to do a full replacement.

The National Response Center data on past AFFF and foam releases is really interesting to me. You can actually see that most releases are not recorded as having a fire involved in the upper left here. The teal is the no for fire involved. And I pulled here all incidents that described AFFF specifically or types of unidentified foams. There are spills, equipment failures, operator errors, spills coming from many types of facilities, including vessels, fixed facilities, mobile. They range in size from a bit of unidentified foam to, for example, a petrochemical fire that accidentally released 130 ,000 gallons of AFFF from its containment zone. So it’s one thing to spray AFFF on a fire when know that you need it, but having a release due to storage issues is something that we less often considering can definitely be addressed with planning. So if you believe there’s been a source of PFAS at a facility, the next question would be where did it go? Into the product? Into landfills? Into the environment? Into what media?

Because PFAS are present, residual sources can remain in equipment or lagoon sediment or soils long after replacement products are introduced. My overall advice on understanding where PFAS can be found is to not trust your gut or your previous experience with different chemicals. The concentrations of concern are so low, the properties of PFAS are quite unique, that you can have sources from pathways that you don’t classically expect. For example, contaminated surface water has been found to flow downstream, slowdown, pool, infiltrate the bedrock where it’s pooled, and still form groundwater plumes exceeding advisory levels. PFAS emissions to air have impacted rain and infiltrated groundwater, upgrading it or upstream of a source, and I know this list is a bit alarmist as all sources aren’t equal magnitude and different pathways exist. My point is more to be all inclusive in your consideration until you better understand the conceptual site model. Unfortunately, time and waiting through years of rain doesn’t necessarily mean PFAS have washed away from a site. It’s retained well in surface soil, and it can wick to the surface during wetting and drying cycles, allowing for off-site transport by surface water flows.

At complex AFFF sites, there’s a tendency to find multiple high-strength source areas with a widespread low-level concentration spreading in areas in between. This means that some areas can appear similar to background unless you find the hotspots that are causing ongoing sources. I’ve heard it described as a cloud of low-level contamination being found dispersed around high-strength source areas. In larger water bodies, it can be especially difficult to find a PFAS source, such as unidentified foam discoveries that I’ve seen mentioned in the National Response Center data set. And even if you have a known fire runoff event, it can be difficult to reliably sample at multiple locations and times downstream, particularly given the difficulties with cross-contamination and background confounders, you can’t really catch a snapshot of a large water body to understand what’s there. So modeling can become another weight of evidence to add to the chemical forensics and understand the full picture. At a larger scale, even if a site discharges to a diluted water body, it may be contributing greater mass loading than smaller, more acute sources.

A study out of the University of Wisconsin, Madison, found that bigger rivers, for example, were contributing two thirds of the loading to Green Bay, even though the concentrations in those rivers were low and much lower than known discharges from PFAS sites along the Bay. So if there’s a lot of water involved, you may need to model the contribution rather than relying only on sampling that struggles with temporal changes and background levels, et cetera. However, sampling is still often the best first tool for investigation. And on that note, I’ll turn to Eric Leicht to discuss site investigation options at this point in the process.

Okay, thank you, Hillary. As Hillary has indicated, PFAS compounds may be found in a very wide variety of commercial and industrial applications. And if a facility manager or a client has raised PFAS as a potential issue, you know, as a result of the saturation level news and literature coverage or industry group notices, or potentially a request for information from a state agency, as was mentioned previously in the kind of the hunts that some of the states are doing, or has come up as an issue in a potential transaction, it’s tempting to want to just get out in the field and investigate the potential for impacts. But there’s probably a better place to start or at least to start considering while you’re generating a sampling plan. So I think the better place to start or rather work simultaneously with sampling is to determine if the identified PFAS at your facility are critical to the process product or the facility. So if not, a big chunk of liability may be mitigated by simply eliminating PFAS use. If it is a critical component or, you know, you need it for that special kind of firefighting, identification of replacement compounds can be next, another step to further limit viability. And it’s our experience that many facilities have already undertaken or are in the process of taking these steps.

A similar process played out, you know, think back to the early 2000s, as many facilities moved away from using chlorinated solvent degreasers to aqueous or non-hazardous solvent systems. And that was, you know, partially to limit exposures and also to limit that liability going forward of having that chlorinated solvent in your facility. So again, many facilities have probably already taken this process or are thinking about doing it. It should be noted though that some of the replacement chemistries are still in the PFAS families and are already garnering similar scrutiny to the legacy PFAS compounds. So that said, we are finding that many of our clients have or are planning to take these elimination steps, but there are kind of caveats to it. Finally, if elimination or substitution isn’t practical, then we need to do a thorough review or advise our clients to do a thorough review of how PFAS are handled. This includes storage, use, waste generation, and disposal. This process needs to be completed to identify kind of best practices to minimize the potential for future releases, minimize waste generation and disposal, because there can be back-end liability based on that waste disposal. And also, we need to comply with the newer upcoming regulations.

As Hillary mentioned, there’s the TOSCA 172 chemicals that will require reporting sometimes. So once a potential PFAS issue or impact is identified, and we’ve also evaluated it for elimination, replacement, or best practices, the next logical step is to collect samples. Where to sample, what to sample, how to sample are, of course, going to be critical decisions. So first we need to determine into what potential media PFAS may have been released at our facility. Do we have air emissions, wastewater discharges, or releases spills to soil or groundwater? Once we’ve identified these, we can focus our investigation. Air emissions, typically we don’t do very much air sampling for PFAS analysis, rather we identify an air emission source, PFAS air emission source at a site, we’re going to look at that as a potential site-wide source and we’re going to look more broadly at other media, soil and groundwater, to determine if there is any PFAS impact related to that air emission.

For wastewater, wastewater treatment plant influence or effluent samples may be a good starting point for facilities actively using or that you suspect to have used PFAS in a process. Many municipalities, as mentioned, have already requested this type of information from industrial discharges. So, looking at discharge permitting and reporting, you might be able to turn up some information on whether there is PFAS in a wastewater stream. If you do identify that PFAS in a wastewater discharge, then start thinking about, well, could there also be soil or groundwater issues at the site related to releases of wastewater and also liabilities related to any on-site wastewater human plants. So this is a gray area right now as PFAS are not universally regulated as far as wastewater is concerned. So this is kind of information that we would take to kind of focus our next topic which is soil and groundwater sampling. So if we have specific releases known, you can go out and collect soil samples at those locations. So if you have a source or a spot on your site where you know firefighting water with foam ran out of a building and collected and you can sample that that soil there and see if it’s a hot spot.

If releases are suspected from more general industrial operations, for example, we all know that PFAS was often used in plating operations, our sampling regime would look something similar to a regular Phase 2 for a chrome plating operation. We would look around the process areas, material waste storage areas, and any associated wastewater facilities. Note that based on their solubility, it’s often logical to focus on groundwaters to screen for PFAS rather than doing a lot of soil samples. PFAS analysis as an emergent contaminant can be costly. So focusing on groundwaters to screen for impact may return kind of more bang for your buck per analysis if the site geology is appropriate. So if you have transmissive soils and shallow groundwater, you can reasonably expect something like PFAS compounds to have infiltrated with precipitation into that groundwater and kind of disperse them in the site. You might be able to identify them more readily than just going out and taking a ton of soil samples.

So we decided there may be a PFAS issue at our site. We want to sample soil and groundwater to quantify the potential liabilities, but there are literally thousands of unique PFAS compounds which were produced over several decades and the labs just aren’t, it’s just not possible to analyze every compound. The labs don’t have the capability to analyze everything, and if they could, the costs would be prohibited anyway. So sampling requirements or guidance also varies widely from state to state. Some are pretty good. Some states still have essentially no guidance at all. So a basic starting point for sampling for PFAS is specifically look for PFAS and PFOA. These are probably the most commonly used PFAS compounds historically. Another approach could be to analyze all the compounds the lab is capable of. Generally, labs are doing around 45 to 50 PFAS compounds.

One issue with either approach is the regulatory environment and the locality where your facility is based. As noted, some states have no guidance and therefore there may be no criteria to compare your results to. Other states may have guidance or criteria on PFAS, PFOA only. Illinois started out with just a couple and I think they’ve added some more to their list or at most a few other compounds, PFAS and PFOA, plus I think five other compounds in Michigan. Some agencies may require a broad suite of analysis regardless of the regulatory criteria. So going back to Michigan, while it may only have seven criteria promulgated, they typically require 44 compounds to be analyzed if you’re doing an investigation that’s gonna be submitted to the state. One way around this maybe is to do the top or TOF analysis, which is basically a total PFAS type analysis.

However, uptake of those methods have been pretty slow by regulatory agencies. Typically, agencies are gonna set screening or cleanup criteria based on toxicity data for specific compounds. So there is no tox data for the top analysis because it’s not a specific compound. It’s a whole group of compounds. So for anybody with a leaking underground storage tank experience, you may recall that in the early 2000s, many states initially had cleanup criteria for total petroleum hydrocarbons, TPH. But as their programs became more risk-based and became updated with tox data, those TPH values were rescinded or reduced to kind of initial screening levels. For that reason, there isn’t a specific tox data for TPH. So it was kind of relegated to more of a screening thing. So TOP might be useful, but it’s going to be more of a screening tool than something that you can really analyze liability with. So the sampling screen can range for anything from a couple of compounds up to 50 compounds. And what we choose is really dictated by our client’s requirements and the regulatory environment.

So if our client is purchasing a potentially PFAS impacted property, casting as wide in that as possible, you know, all 50-ish compounds may be appropriate. You can determine, you know, what’s there, even if there may not be criteria to compare your data to. If a client simply needs to satisfy a regulatory requirement, focus in on those, whatever the state’s asking you to look for. And then in some cases, if you’re in a transaction setting, the seller, if you’re on the buy side, the seller may only agree to analysis for compounds that are regulated in the state. So two or a few compounds in Michigan, seven or eight compounds in Michigan or Wisconsin. And if there is no regulatory criteria at all, you might have a hard time convincing a seller to let you do any sampling at all. So in summary, there’s definitely no one-size-fits-all or analytical guidance. It really depends on the regulatory environment and your client’s needs. So we’ve scoped out an investigation. We’ve gone through the analysis or the potential analyses and selected our analytes. And we’ve gotten to the point where PFAS impacts identified, how do we manage that risk?

So, as previously discussed, the first step is, at the site level, is removal or replacement or best management practices. Again, many of our clients have already started down that road. But next is to address the impact of media soil or groundwater itself. Soil remediation may be completed by traditional methods. Digging But landfill disposal and other disposal options, like incineration, is becoming more difficult. Landfills may not want to take on additional liability for disposal of their own PFAS-containing materials. They already have their own issues with disposal of PFAS-containing consumer and industrial waste entering their leachate streams. And incinerators likewise are becoming more worried about incomplete destruction of PFAS, leading to air emissions, downwind deposition, and impacts being created that way. Technologies for in-situ soil remediation, where PFAS itself is removed or destroyed rather than being simply immobilized, are not really available at this time.

For groundwater impacts, they also may be mitigated in place, but again with current technologies, the PFAS are typically not removed or destroyed, but rather sequestered in the impact material. Typical traditional pump-and-treat with granulated activated carbon, GAC, used to absorb the PFAS from groundwater may be viable, but ultimately disposal of the GAC may become a problem in the future. And again, a PFAS containing waste once the GAC can’t be regenerated anymore. So we’ll have similar issues to disposal of PFAS-impacted soil. Engineering and institutional controls, capping source areas, and limiting site use are good options at this point, while other remediation and disposal technologies kind of catch up to the demand for robust, destructive remediation technologies. And that transactions, or even for facilities that are trying to manage their risks, clients often ask, we just want a clean site.

How do we get to a clean site? or what is the pathway that we can follow to estimate overall costs and get to a cold site. But again, as we discussed, removing PFAS from the environment at this time just isn’t possible. So recall from the first few slides that Hillary presented, it’s the very properties that make the PFAS compound as useful industrial and commercially. So the slipperiness, heat resistance, durability, longevity, solubility, that’s what makes these compounds likewise very difficult to destroy. So as noted some proven technologies such as pump and treat with GAC are effective but the throughput on such systems and the current cleanup target levels which are extremely low combined to render something like pump and treat pretty ineffective for a as a large scale remedy. Therefore right now removal of PFAS to below identified threshold thresholds often not going to be achievable, especially over shorter relevant time frames.

So overall, approach that we’ve been taking is risk-based, but incorporating the concept of reasonably practicable. So we use a risk-based approach, but we can make allowances for what is achievable based on our available technologies, environmental sustainability of the overall solution and the proportionality between costs and current and future risks. So as we’ve discussed in some of the previous slides, the full remediation of PFAS in the environment, generally we’re talking about soil and groundwater is not currently practical, although there are promising technologies that may be proven in the near future. But given the lack of these proven remediation methods, which are accepted by relevant regulatory agencies, RPS is taking a measured approach in assisting our clients. So, for example, RPS is assisting Australian defense manage their pre-fest liabilities by focusing on basically a couple tax. One, control source areas. Soil removal, if possible, if you can find a place that’ll take it as a landfill or other disposal option, or through engineering and institutional controls. So cap any impacted soils, impose land use controls so that soils aren’t disturbed and there aren’t any exposures to the soil. And then second is to control or reduce migration.

So pump and treat, and again we’ve mentioned pump and treat with GAC, it can be used if it provides a real reduction in the mass of PFAS in the affected groundwater or aquifer, or if it’s effective to control the migration of that water flow, so keep that mass of PFAS on site. And then use of other methods such as in-situ stabilization is also pretty common in our work that we’re doing for Australian defense, so something like plume stop is commonly used. So in this way PFAS liabilities can be managed in the short term, reducing the potential for exacerbation or movement of the existing impacts and migration of impacts while we wait for those emerging technologies to be validated and employed in the future. The costs for interim mitigations, you know, soil disposal, in-situ treatment, these can be readily estimated for use by facility planning, environmental set-asides, escrows, or other methods to establish appropriate post-closed mechanisms to fund these kinds of mitigations.

And, you know, the final remedies, you know, The final destruction of PFAS are still under research and development, so estimating costs to get to a clean site at some point in the future is somewhat more difficult, but we can kind of make projections based on the current technologies that have evolved for other once-emergent contaminants, maybe like 1 ,4-dioxane, and see how the technologies have evolved for those cleanups. We can project that on how we think the costs will eventually play out for PFAS remedies and use that to generate some reasonable estimates for future remediation. So the main idea is that identify and manage liabilities. So first, determine if you have a PFAS issue at your site. Again, simple screening might not be enough. The MSDS sheets or other information may not come out and say PFAS. So you gotta do a little bit of research and see if you actually have a problem or a potential PFAS use and potential releases.

Second, eliminate or manage if possible. If you can’t eliminate or replace, then investment is a good way to minimize the potential for any releases as possible. Three, investigate. We focus mostly on soil and groundwater, being a proxy to get a broader picture at most facilities. And then four, manager impacts, take a risk-based approach with that reasonably practical caveat. Remediation if possible, interim mitigation as necessary, admin controls, engineering and institutional controls and then wait for that emerging technology for complete remediation to present itself. And now we’ll hand things off to Ryan Moore of Regenesis

Yeah, thank you, Eric. And thank you, Hillary. Very good information. I’m going to shift gears a little bit and just kind of talk a little bit about some of the in situ solutions that we are using at Regenesis for PFAS treatment. And then just a very brief overview of, you know, how do you work with Regenesis when you have these projects and you really want to kind of, you know, go through that process of evaluation and getting out in the field doing treatment. You know, first, kind of conceptually, when you take these PFAS sites, they’re kind of broken up, and most, you know, contaminated sites are broken up into three major parts, right? You’ve got the source soils, which is a lot of times, you know, where the high mass is at, like Hillary was indicating in that Beto soil, significant amount of mass that can reach out over time. You’ve got source groundwater, usually right within the close proximity of the or soils, and then you’ve got more of a downgrading plume that typically will have lower concentrations.

So I’m gonna kind of walk through a few different treatment options that we use at each one of these different parts of the system. Now, first with the plume treatment, what we’ve been doing now for the last five or six years is using coil activated carbon or plume stop. And I’ll talk a bit more about that in a minute as typically in kind of a reactive barrier configuration. So we would add that plume stopper, that clonal activated carbon in situ. And then the goal is to really enhance the attenuation of the PFAS. Now ITRC just says enhance attenuation, nothing more than the result of applying an enhancement that sustainably manipulates a natural attenuation process leading to an increased reduction in mass flux contaminants. That’s exactly what we’re doing. And why are we doing this? Both Hillary and Eric talked a lot about risk and risk reductions, right? So what is risk?

It’s nothing more than the hazard times the exposure. US EPA has a few different mechanisms when using natural attenuation or enhanced natural attenuation to address risk associated with contaminants. When we’re using that chloro-activated carbon, in essence what we’re doing is reducing the contaminant mobility and bioavailability. By doing that, you know, when that PFAS absorbs to the activated carbon, that exposure is no longer there. The hazard is still there, but that exposure is not. And when you remove that exposure, you eliminated the risk. Now, this idea of using enhanced natural attenuation to address PFAS is not something new and it’s something Regenesis has come out with. And as an example here, I have an article that is referenced here from Chuck Newell with GSI. And, you know, Chuck’s kind of really laid out either lines of evidence that you can use to verify or, you know, confirm that and the enhanced attenuation strategy is reducing the risk at the site.

He’s also come up with a more recent one that lays out several different mechanisms to increase enhanced attenuation and one of them specifically is adding absorbent to the aquifer again to increase that attenuation side. What is the chloral activated carbon we’re using? It’s a trait named plume stop. It’s a form of activated carbon where the activated carbon particles have been milled down to one or two microns in diameter. It’s very, very small. that carbon particles are then suspended as a colloid in a water polymer solution. It does a few things, but it allows it to distribute widely under low pressure. It’s very fast absorption because of the particle size being so small as well. In essence, what we’re trying to do is convert that aquifer into a purifying filter. What are the main modes of action when addressing PFAS, right? You know, PFAS is non-degradable, so obviously it’s still there, right? So you have this kind of dynamic absorption of the PFAS to the activated carbon.

In essence, what we’re trying to do is increase the retardation of that PFAS compound in the groundwater. And what do I mean by retardation? So if you look on the right, it’s just a quick chart that kind of talks, gives a couple different factors here. So if you have an R1, that means it’s a retardation factor of one and that contaminant moves at the same speed of groundwater. An R2 means that contaminant moves half the speed of groundwater and then an R10 means that contaminant moves at one-tenth the speed of groundwater. So for example, if groundwater moves 100 feet a year, an R2 means that that contaminant would move at 50 feet a year as it relates to groundwater. And then that same contaminant, if you had an R10 factor, would move at 10 feet per year as it relates to groundwater moving 100 feet. When we’re doing the plume stop treatment, we’re significantly increasing these retardation rates. And some of the research that we have, and we’re not gonna get into today, we’ve got a lot of technical information to provide you, but in essence, what we’re doing is increasing retardation factors up to over 10 ,000.

So again, that contaminant would move one 10 ,000th the speed of groundwater. And that’s just, we’re really binding this PFAS up in decades in many cases. Moving along kind of one of the other components here is what about source zone treatments, right? Why would we wanna look at source zones? Both Hillary and Eric both kind of touched on this that you’ve got to do some kind of control, right? So when we’re looking at it, we want to manage the soils in place to be very sustainable versus come in, dig them out, take them to the landfill or somewhere else. We’re trying to incinerate them, which has not been shown to be very effective in a lot of cases. Again, when you’re using the source zone controls, you’re promoting that enhanced natural attenuation of the plume. We’re reducing the long-term PFAS mass discharge into the groundwater. And ultimately, what we’re really wanting to do is reduce the leachability from the Beto soils, reduce infiltration of water from precipitation and the mass discharged into that groundwater. And then in combination with our downgradient PRBs, we’re really trying to ultimately mitigate the risk associated with the campaign.

And then finally, we in the source sounds also is we want to kind of put a horizontal blanket, so to speak, in between that source soil and groundwater. Again, it’s kind of a downward movement or filter downward movement in water. So what are we using for the source control so we have a new product we call it source stop. It is another form of portal activated carbon, just a more concentrated form but it’s the same particle size of that one or two microns as the plume stop. It’s formulated differently though and so it’s made specifically for source treatment and both the mixing within source soils, beta soils, and you know potentially spraying at the bottom of the bottom of excavations and then awesome injection within source zone and I’ll kind of talk about that in a second. So a few different approaches that you can use and I was kind of just touching on this that that we’re looking at and are doing currently is taking that Beto soil and mixing in source stop with other amendments potentially.

Something that, you know, again, we’re trying to either reduce the legibility of that PFAS into the groundwater, or we’re trying to reduce the permeability or infiltration of precipitation through that Beto soil where we capture and pick up some PFAS and discharge in the groundwater. Another approach, again, is using this horizontal barrier concept where you hold the source soils out, you spray the bottom of the excavation, that source stop will go in and kind of diffuse down into the bottom of the excavation and really cover that capillary fringe above the groundwater. And then again, that’s a long-term filter in place to prevent the spread moving forward. And then the other approach would be to just directly inject the source stock right below the bed of soil to act as a large filter again to minimize the discharge to the overall plume. What we really want to do and most of our project sites that we look at is to combine both the plume treatment and the source treatment. And what are some of the benefits and why would we want to do this, right?

You know, one, again, prevents that mass discharge from the source, only going to give us more longevity in our PRB configuration downgrading, stop the eviction, stop the flow, enhance the natural attenuation. And when we combine these approaches and kind of give a full, you know, spectrum approach to address in the PFAS out-of-project site, it allows us to kind of offer a warranty of treatment for long-term risk reduction. What is that warranty? Well, we call it plume shield. In essence, what we’re going to do is come in, evaluate the total project, give you a price to meet the goals of the treatment. And it could be a numerical value, percent reduction, and the time, longevity, et cetera. We’re gonna go through the design process and I’ll talk a little bit more about this in a minute as I walk through the process of working with Regenesis, but we’re gonna go through the design process, probably do some field testing. Then we’ll go out and we’ll do the actual work. That could be the source reductions that we just talked about. It could be an installation of a PRB along a property boundary.

Whatever that work may look like, we’re gonna go out and do it. And then we are gonna have a commissioning phase. that commissioning phase just means you do the initial work, we monitor for a few months, do we meet the objectives that we set out to meet. If we don’t, we’re going to go back out and make sure we do meet those objectives. When we do, and we hit the target goals, whatever they might be, then we certify the treatment. And then at that point, our standard 10-year warranty starts. And so that means any time over the next 10 years, if we’re not meeting the standard that we set off, set forth in the beginning, then we’re going to come back out and retreat the site. How does the process work with Regenesis? So, you know, they’ve kind of got these five major categories, right? Initial site evaluation, going through technology selection. With PFAS, you know, we’re going to look at our photo carbon products that if you’re using, you know, if you have a coordinated solvent site or petroleum site, you know, maybe we’re looking at ISCO or ISCO reagents, whatever they might be.

And throughout the process, we’re going to talk with you and really kind of work with you to understand yourself more. We can go through the technology selection. We’ll put a design together. At the design phase, there’s a lot of other steps I’ll mention here in a minute that we go through to get it right. Then we go out to the field and actually implement the project. And then we’re also available in the back end for post-evaluation. We do a lot of performance review memos just to kind of say, how does my performance at my site fit with other sites similar to it? You know, as an example, if we’re going to go out and do like a PFAS site, and we have this reactive barrier configuration is what we want to do. You know, we don’t just immediately go out and start injecting, you know, we have this concept in place. So what’s the next step? Well, really, we want to look at, you know, we do a lot of in-house modeling, and we have a program called PlumeForce that was developed internally.

And in essence, what it’s really going to do is help us give this kind of long-term pictures of what treatment should look like, or how does that reaction or the plume reductions look like after we do the application, right? How should that plume behave in five years, 10 years, et cetera? And so the model itself is nothing more than a competitive adsorption model. If it’s something like coordinated solvents, you can even account for degradation or changes from, like, say, PCE down to vinyl chloride. We’re using compound-specific isotherms that are developed for a variety of VOCs and PFAS compounds as well. And that gets inputted into the model, along with site-specific considerations. Soil type, you know, is it, you know, silty sands, is it clay, is it gravelly, you know, what is the groundwater velocity in the area? What are the calculated mass flux? those are some important considerations that we need to understand at a project site to make sure we can achieve the goals. And then variations, you know, maybe vertically if there’s changes in the geology, make sure wherever our treatment’s going to go, we understand those changes. And that could be, again, you know, a lot of times we see significant changes in mass flux, you know, within the interval that we’re treating. And that can often also go with like changes in the geology, the ground work flow. And then the time, how long does this need to work?

For our PFAS projects, we’re designing a minimum of decades with 10, 15-type years worth of treatment from a one-time application. So the model is a very useful tool for us. Before we actually go out and implement the project, we have a step called design verification testing. In essence, it’s a subservice investigation. The help is specifically with the application. It’s done in a separate mobilization before you go out and do the full-scale application. And the reason why we’re doing it is that the data from the site conceptual model is often used for delineating risk of a project site, you know, the totality of the risk. It’s not always really good given enough data density in specific areas where we’re trying to treat. You know, we’re going to want to do a little higher, a little, you know, a little bit more investigation or have a higher, you know, level of security in terms of like our, you know, what thinks going to happen in some surface and some of those, you know, tools are high res characterization.

So HPT, maybe we’re doing an injection test, additional soil cores, and then flux tracers, and we want to understand, you know, especially with plumb stock, what does that mass flux and what interval or depth is the, you know, the highest concentration? Again, if you go in and just take an concentration of the mass flux or an average speed of that groundwater, you may really underestimate specific zones and if you don’t treat a quarter into the highest mass, it could look like non-performers. So again, we go out, we do the DVT. After that, we optimize the design and then we go on start doing the fieldwork. Well, when we do the fieldwork, we don’t just inject very quickly and then walk off-site. You know, we take our time and we really want to understand, you as we’re injecting or as we’re going through the process, you know, we need to do some confirmation sampling as well.

So we’ll do some soil core, maybe add some plastometers, but what we really want to see is, you know, can we confirm that the plume stop went where it needed to go? Are we covering that flux zone? Again, if we’re, especially with something like PFAS, it’s non-degradable. So if you don’t build your underground fence and, you know, have no holes in it, you may have slippage of PFAS compounds through that treatment and at per trillion levels that are, you know, what we’re seeing from a regulatory standpoint, you know, it doesn’t take much to get through. So we’re going out doing real-time distribution confirmation sampling. If we see something where it’s not, you know, we’re not getting the ROI or where the distribution is just not there that we expect, our guys are trained to get with the project team right away. You know, you can plan a lot on paper before you go out in the field, but everything you get out in the field changes. So we need to understand very quickly while we’re there, what changes needed to happen and build consensus with the entire project team. That’s not just with our internal team, but that’s also externally with our clients. Make sure that we understand what’s going on and then make the adjustments while we’re there, again, at the end of the day to make sure we have successful projects.

Just a quick summary, you know, The coital-activated carbon technologies of plume stop and source stop are absolutely proven to address PFAS risk. Our process from the modeling through the design verification, testing, application, placement validation, all leads to very successful projects which allows us to give us standard 10-year worries on PFAS projects. And no one else out in the industry can say that.