Hello and welcome everyone. My name is Dane Menke. 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.

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Today’s presentation will discuss coupled aquifer restoration and water reuse and the application of sustainable remediation solutions. With that I’d like to introduce our presenters for today. We are pleased to have with us today Avram Frankel, Managing Principal at Integral Consulting. Avram Frankel is a professional engineer, technical expert, and program manager with more than 30 years of experience on a wide range of commercial, industrial, municipal, state and federal sites regulated under numerous state and federal programs. A civil and environmental engineer licensed in California, Oregon, Washington, Colorado, Georgia, and Hawaii. Mr. Frankel provides his clients with strategic risk management and technical analysis in support of due diligence, redevelopment, technology evaluation, site investigation, water treatment, remediation, and legal and litigation matters.

We’re also pleased to have with us today Gareth Leonard, Managing Director for Regenesis in Europe, Gareth Leonard manages a dedicated team of in-situ remediation specialists to provide the design and implementation of remedial solutions for environmental consultants, remediation contractors, and end users. He has worked in the remediation industry for over 25 years, having provided successful remediation designs and implementation for over a thousand projects across Europe, the Middle East, and Africa.

All right, that concludes our introduction. So now I will hand things over to Avram Frankel to get us started. Thank you. I just want to thank Regenesis for inviting me to speak about this topic today, and I’m honored to be presenting with Gareth and look forward to hearing his talk as well. Talk about coupled aquifer restoration and reuse, which is an old topic actually in our industry, but it’s still very relevant, and I’m hoping to sort of re-engage folks in this discussion. So why consider this topic at all?

Well, a number of reasons, you know, in some parts of the United States, and certainly the world, water supply is often limited, parts of the world demand is increasing, climate change is affecting things in different ways, some cases it’s increasing supply and other cases it’s decreasing supply. So there’s a lot of uncertainty around water supply. There’s many opportunities for reuse, I’m going to talk about that a little later in presentation with current projects. And I’m really just trying to restart an old conversation and get more input and collaboration with other remediation and water supply professionals.

The reality is, is the ultimate fate of treated water not only affects future projects that we may engage in in the remediation industry, but it may change existing ones. I was just talking to a colleague this week in Fort Collins, Colorado about a large extraction treatment system in California where the end use is now changing because of regulatory considerations. The water is going to go into the aquifer now instead of just being put into a surface water. And I think also not only affecting our industry, it’s just an interesting topic for many of us that have been doing this a while.

So let’s just talk about, sometimes this isn’t that popular of a discussion, but it’s one that I like to engage in, which is when we talk about groundwater remediation at sites, scale becomes very important. And sometimes we forget that there is a wide range of scale in our projects, all the way from small projects, say at a gas station, or a small commercial facility, you know, all the way up to mega plumes, which can be many miles long. And what’s my point here is that there’s a point where not all technologies are applicable. So there’s an optimal range for the application. We have so many great in-situ technologies.

I mean, I can think back when I started this industry, we had basically none. And now we have so many options for source zone treatment. But there is a range there. And I personally have been involved in large-scale in-situ remediation projects that probably were pushing the limits of the scale where the application was efficient or economically viable. And I think even in some cases, some of the projects I’ve worked on in the past, if we really did a life cycle analysis today, we may not have picked that option. But then at smaller scales and medium scales, institute technologies are, as we all know, incredibly applicable and do pencil out very well. As we get into the larger projects where extraction and treatment of groundwater really becomes one of the only options.

We go through a range where we have combined remedies, so application of in situ and range of technologies and source zones coupled with extraction and treatment. And then when we get to the mega plumes, and I’m talking sites with plumes, two, three, four, even five miles long. I know many of you out there have worked on these kinds of projects and you know how challenging they are. We really get to a point where extraction and treatment is increasingly the only option. And that’s kind of more what I’m going to be talking about a little bit today, the upper end of the combined remedy scale and the areas where extraction treatment is the only option.

So just looking at another way is we have nice little cartoons here that some of my pals here at integral put together, but we do have sort of the gas station level, relevant topic today with PFAS, you know, a triple F releases at fire training areas, some kind of a plume with multiple sources in a city environment, as increasing magnitude of impact of a plume, just generally speaking, increases, there’s a correlating increase in opportunity for reuse of water that’s extracted. And that’s, I think I’m speaking quite generally here today, but it turns out to be true. So let’s talk about groundwater for a minute.

Let’s just zoom out for a minute and think about globally what’s going on with groundwater. And I do wanna give credit to the National Groundwater Association because most of this information is available on their website. But anyway, globally, groundwater provides almost half of all drinking water worldwide. About 70% of groundwater withdrawn worldwide is used for agriculture, which may not be surprising to folks and maybe surprising to others. How much of the world’s groundwater is contaminated is an open question, but I think we can assume that it’s expanding due to occurrence, releases, regulation, and then increased detection. And I think we’re seeing that with PFAS right now, but we’ve seen it in the past with many other emerging contaminants. So, and also just think of all the places in the world where groundwater is not regulated, but could be regulated in the future. So I think what we consider to be contaminated aquifers, the contaminated groundwater is only going to increase.

If we talk about the U.S. just for a second here, groundwater is a significant water supply source. What’s interesting is the amount of groundwater storage really dwarfs our present surface water supply. And that’s really not gonna change. About 90% of our freshwater supplies lie underground, but less than 30% of the water we use comes from underground sources. So it’s not hard to posit out there that we’re probably gonna use more groundwater. And in fact, use has been gradually increased. Around 40% of the US population depends on groundwater for drinking water supply.

Again, similar to globally, irrigation accounts for the largest use of groundwater in the United States. So, you know, what am I talking about? What types of systems are we actually talking about? And why are they relevant? Let me just run through some remediation applications. One would be extraction of groundwater, treatment, and then direct distribution into a water supplier or direct distribution for agricultural use. There’s nothing new about this. This has been happening for a while, for decades, actually. Then there’s the situation of extraction, treatment, and then reinjection into an aquifer or re-infiltration through spreading basins or other means.

And then we have combined remedies where those things are going on, but there’s also source zone remediation by other technologies, as I’ve mentioned before. So all these different things are going on. And I would add, I think infiltration is something that we’re going to see more of. That’s coming from a remediation perspective, not a restoration perspective, but there’s a whole other world here of production wells being used as extraction wells, where the entry point for reuse is through drinking water systems. These are drinking water supply applications where a well field used for a water supplier ends up, by one means or another, becoming essentially a remediation system. And that’s happened. We have NPL sites where an operable unit, the remedy is actually an existing drinking water well field.

We have also the situation where treatment is added to existing drinking water systems. And that is something that people don’t really talk about a whole lot in the remediation industry. But I can say from my years of working in the one to trichloropropane litigation world in California, there are literally hundreds of systems where granular activated carbon is being added to, which means that those production wells are now having treatment for 1, 2, 3 TZP and essentially aquifer restoration indirectly is occurring. We’ve seen that with PFAS. We’ve seen it in the past with other soil fumigants. We’ve seen it with CVOCs for years, but we don’t really talk about it that much. And then we have the situation with managed aquifer recharge and aquifer storage recovery wells, some of which I’m showing here, which is really a perspective from the water supply side. And what I’m really hoping to talk about here is how we can water supply and remediation discussions can come together.

We also have this situation of indirect potable use, like what Orange County Water District has, where wastewater is being treated and then re-infiltrated into an aquifer that’s ultimately used for drinking. So I think program integration as part of the future, and I’m really interested in other people’s perspectives on this. So we kind of as part of preparing to have this little chat today, we did a little experiment, a little research project over here at integral. And we’re like, well, how what kind of a data set could we use to sort of, you know, look into this a little bit more, at least preliminarily.

So we decided after poking around a bit to look at all the national priority list sites under CIRCLA in the United States, and that’s a pretty big data set of remediation program, almost 2000 actually, if you include planned remedies, remedies implemented, and actually sites where remedies have been completed. And I want to thank, we have a great intern program this year at integral, which if anybody out there is interested in applying for that next summer, we’d love to hear from you. But we have this wonderful intern, Hannah McCollum, who helped me with this and we did a web scraping and data analytics exercise and let me just walk you through what we came up with here. So this is all the NPL sites in the US.

These are the NPL sites where there’s groundwater extraction as part of the remedy. This is now looking at of those sites how many have any form of reuse. So that could be for drinking water application, for agricultural irrigation or reinjection back into an aquifer. And you’ll see we’re getting fewer and fewer little dots on the map here, and it’s kind of interesting to look at where the concentrations are of these dots. And by the way, I just want to say there’s some MPL sites in Europe, DOD sites, and there’s a couple down in Puerto Rico which we’re not showing. So of those reuse sites, here’s the number that are drinking water use. So the data set’s getting smaller here.

And here’s agriculture. So it is interesting that there are agricultural applications and reuse coming out of NPL projects, but again relatively few. And then here’s the sites that have some form of groundwater re-injection. Again kind of interesting concentration in the northeast, but overall relatively few sites. And this is just looking at the different kinds of reuse by category and you kind of see the spread here, just adding it all up, integrating it for folks to see together, and then kind of zooming all the way back out. Here’s all the sites. Here’s where we had groundwater extraction.

Here’s where there’s portable reuse, irrigation agricultural reuse, and aquifer injection. I’m happy to share these slides with anybody. As a result of our little research, just reach out to me. I’d be happy to do that. So kind of just summing it all up, what did this really come down? So there’s almost 1 ,900 NPL sites. 337 have some form of groundwater extraction, which is 18% of the total. Of all of those, so 67 have some form of groundwater reuse. So 4% of the total are 20% of the sites with extraction. And then of those 67 sites, there’s 28 drinking water applications, 38 reinjection applications, and nine agricultural. Some of these sharp folks out there realize that those three blue numbers equal 75 and not 67. And that’s because there’s eight sites actually where there’s multiple use, some combo of drinking, alcohol, and injection. So I think the punchline here, but we kind of want to dig into this more moving forward and we may publish a paper on this is sort of why is all this happening. Let’s talk about that a little bit. And let’s also talk about that that’s just MPL sites. There’s reuse happening on state regulated sites and there’s reuse happening in other contexts.

So let me just give you some examples. The Central Trucking Meadows Remediation District, this is an airstripper tower on the left, brought up their website, out clearly available. This is a long-standing state regulator project in Nevada, in the Reno area, where there’s just been an integration of production wells, as I was mentioning before, for use as capture wells with treatment. And it’s a long-standing, very successful project. There’s nothing to do with MPL sites. There’s Reiss Center, which I was fortunate enough to be the program manager on for five years when I was at Arcadis. And many very talented people at Arcadis were involved in this project, which was the remediation of a three to four mile plume from the old Reiss Air Force Base. It’s part of a big redevelopment project, Reiss Center project. You can Google it and check it out. It’s really kind of a great story.

But this plume was remediated by, is a combined remedy situation, groundwater extraction, then very creative reinjection. And also we did in situ bioremediation in source areas. But really the remediation was heavily driven by groundwater extraction or reinjection. An aquifer was used for irrigation purposes. That’s also a storage site and there’s much more to talk about on that one. But I just want to mention it It was a Ricker site, not an MPL site, and it did achieve closure under Ricker. This upper right is the Kennecott Mine. Many of you are probably very familiar with it in the Solid City area. Very interesting, also long-standing natural resource damage settlement that includes an operating system extraction treatment and distribution of water from the mine to a regional utility for drinking water.

Also, long-standing, very interesting project regulated by the state of Utah. I just want to mention a couple of other ones because this one’s been in the news. Stewart, Florida, which if you’ve been following all the PFAS news, was the bellwether case for the multi-district litigation, which is now subject to a large settlement. Anyway, many of us were involved in evaluating the Stewart site, but it’s a long-standing, a couple dozen production wells where Florida has incorporated a couple different VOC remedies and also PFAS. Now PFAS is being used and the primary remediation mechanism there is the production wells. So I’ll wrap it up here pretty quickly.

So thinking about many existing systems, we have systems that are being built, we have all kinds of groundwater extraction, combined remedy systems that may or may not be considering reuse, but if we were to consider reuse on these projects, some of us are probably doing that right now, here are some technical considerations. And I want to thank my colleague Jeff Davis in Salt Lake City. He’s done a lot of reinjection and reuse work and was helpful in highlighting some of these considerations. So one is geochemistry. I think this isn’t news to a lot of practitioners in the field, but when you’re pulling water out, treating it, maybe blending it, and then injecting it, there can be significant geochemistry considerations.

We’ve certainly seen that on large scale in situ remediation projects, but it happens in this context as well with extraction or reinjection or extraction or re-infiltration. So we have to be very careful about managing geochemical considerations so that we don’t create some kind of disillusion of, say, metals out of aquifer matrix and create a plume. There’s a situation with emerging contaminants, and I can I’ve got the battle scars from this one where there’s extraction and reinjection, and what’s being reinjected includes chemicals that are not regulated but then later get regulated. This happened with sulfalane, it has happened with PFAS, it’s happened with a lot of allergic contaminants, x-ray, chromium, perchlorate, where essentially plumes were expanded or created unintentionally. And I think that’s a tough one.

But we have so many lessons learned on this, I think we should be able to get out ahead of this in future projects. There’s the issue of disinfection byproducts. In some cases, states are requiring disinfection prior to reinjection, even though it actually technically might not make sense to do that, it might not be necessary. It’s required. So that needs to be managed so that we don’t create a disinfection byproduct. And Injection well design, I know those of you out there that have done it, do it, know how in some cases injection is easy, in some cases it’s very difficult. So just something to watch out for. That is almost an art in how to effectively design injection wells and injection well network. And then the consideration of the effects of other wells, production wells or domestic wells or other wells that may affect your project. and this is, I want to talk about this a little bit more from an administrative standpoint.

So permitting is a really big issue with these projects, and I know many of you know this and lived it, and I want to also thank my colleague at Integral, James Lesperance. He’s recently come back to us from working in industry and was in the thick of this on a project down in Southern California. But in most states, we have environmental regulation, water supply regulation, and water rights regulation, and typically by three different agencies. Not always, but typically. So, are these agencies talking to each other? Are they aligned incentive-wise politically? Are there mechanisms for everybody to talk together? There are cases where there is great alignment and a project moves forward fairly smoothly. There are cases where there is not good alignment and the interests of these agencies are not aligned and it puts the onus on us as consultants and our clients to work through that process. So, why are there issues?

What are those control issues. There’s pushback in some jurisdictions to using production wells at all as extraction wells. In other jurisdictions, like the one I mentioned at Reno, there’s no pushback. So that’s just the reality of the situation. The really core issue there is that environmental regulators want to have control of all of the infrastructure on a remediation project, but that might not be possible when there’s production wells in the city. So ideally, production wells can become part of the solution, but if they’re not they still need to be considered in terms of the design of the river.In some cases with water rights, simply putting the water back in the aquifer solves that problem and other cases it doesn’t.

There’s the issue of ghost wells in permitting and underlying modeling, so there’s almost always a hydraulic model to support these projects and just the effects of all of these other wells really need to be accounted for to a successful design. So there’s different roles and there’s different priorities, but we have many examples. Let me just look at the NPL sites I showed, look at the other examples. Many of you probably have some examples of where these worlds can come together, where the priorities can align, and these projects can move forward, and we can have more groundwater reuse.

Quickly, and I’ll wrap it up here, some other factors that may change and affect these kind projects. Natural resource damage settlements. We’ve seen many of them. This was a big one in Minnesota and a girl had a role in that. Where our monies may be set aside as part of settlement as we saw in Salt Lake City for projects that can involve groundwater reuse. I think as we move forward in the PFAS world, UCMR 5 monitoring will occur. I don’t think it’s going on a limb saying that We might detect more PFAS. As regulation becomes more uniform, plumes are gonna get bigger. I don’t think it’s a huge stretch to say that more production wells may be affected or that there may be more intersection of PFAS occurrence with remediation projects.

There’s sustainability considerations. There’s political considerations. There’s environment, social, and corporate governance factors where industry, in some cases, becoming much more incentivized to do more sustainable activities and that we’re seeing that play out with remediation projects and then there’s environmental justice. Personally I haven’t seen that be a factor in these kind of projects in terms of reuse but it could be down the road so just something to look out for and that’s all I’ve got. I’m happy to discuss this with anybody and I really just trying to promote a broader discussion on this topic so thank you.

Thanks, Avram, that was really interesting. You touched on a few things that I’m going to talk about, emerging contaminants, you mentioned life cycle analysis of remediation projects, and so I’m talking about something that’s aligned with what you just touched on, particularly with the value of groundwater. Initially, this started as a study into sustainability, and as we went through this further, we sort of realized the importance of what we were doing. So I’ll get into it and see where we go. So I’m talking today about sustainable PFAS remediation, comparing the environmental impact of enhanced attenuation using colloidal activated carbon to a pump and treat system.

It’s a nice snappy title there. So, I’m talking about her and polyfluoroalkyl substances, so PFAS, a topic that whenever far away from it seems these days, everybody’s talking about them. I want to just talk about how the different attributes of these products make them particularly problematic for us. So for one, they are widely used, they’re incredibly useful because they are omniphobic. And so you can use them for all sorts of coatings, waterproofing, oil proofing, all sorts of things. So they’re used everywhere. We’re then using them for foam, for firefighting, so aqueous foam forming foams. So there’s not many other contaminants that we actively pump onto the ground on a regular basis, but we’re doing that with PFAS and we have been doing that with PFAS for many, many years.

So we’re taking this contaminant and putting it straight onto the surface where it can infiltrate into the ground. And then once it’s in the ground, there’s a number of challenging behaviors that it has. One is that it’s retained in the soils for decades, often in the upper part of the Vado zone where you’ll get a reservoir of this contamination that’ll just then leach into the groundwater for decades and decades and decades. Once it then does start to discharge into the groundwater, it’s really mobile. So these big plumes that were mentioned in the previous talk can be created by PFAS, and that’s exacerbated by the fact that it’s recalcitrant to degradation. At the moment, we don’t think that it can be biologically degraded. It’s not chemically degraded. So these plumes get very large.

PFAS is toxic at low concentrations, certainly the longer chain PFAS are, so what it means is we’ve got very large, very dilute blooms, but they’re toxic at this dilution, so they impact large areas, they create a risk over huge areas. And so essentially, PFAS are everywhere. This is a map from Le Monde newspaper, it’s the Forever Pollution map, just looking at known PFAS sites and presumptive PFAS contaminant sites. There’s a similar sort of map for the US that you can see in environmental health news. They use a different approach, but in the US they’re looking at potentially 57 ,000 sites for PFAS. So we’re facing a contaminant that is everywhere. We’re facing dealing with a number of contaminated sites that we’ve already dealt with as an industry before now. So how can we treat it?

As remediation professionals, we all want to remove contamination and destroy it, right? That’s our knee-jerk reaction. So if we look at the different ways that we can do that, this is a graph showing treatment efficiency. So the higher you are on the y-axis, the more efficient you are against contaminant concentration. Well, if we are looking at PFAS, we don’t really think it can biologically degrade at the moment. There’s not much evidence of chemical degradation of the contaminant. So we’re left with physical removal. So physical removal is great for high concentration. Say if you’ve got a gasoline plume, you’re pumping out the high concentrations of free phase contamination, high concentrations of dissolved phase contamination.

But if you’re trying to get low concentration at low targets, you might need to move on to chemical and biological treatment to get you there. And with PFAS, that’s not possible. And the concentrations that PFAS exists in is nanograms per liter. For your gasoline site, you might be looking at milligrams per liter. There might be nanograms or picograms per litre as the target for PFAS. So what that means is you’re pumping a lot of water with not a lot of contamination in there. So you’re pumping huge volumes, you’re running it through granular activated carbon. Granular activated carbon is not very efficient when you’re pumping quickly in an ex situ situation. You need to have very clean gags, so you’re swapping that out a lot. There’s a lot of energy, a lot of equipment being used, a lot of cost and of course it’s a high ongoing carbon footprint.

So are we really going to do that for all these sides when potentially we are going to exacerbate another global problem which is carbon dioxide production and the warming of the globe? So how do we deal with this one global problem without exacerbating another? And the way to do it then is adopt a sustainable remediation approach. So do the life cycle analysis, do the sustainability analysis of what you’re planning and doing on your site, then effectively takes into account the effect on the rest of the planet, the effect on the rest of the site. So you’re not then looking at your site in isolation.

So what is sustainable remediation? So the ISO 18504 definition is the control of risks whilst optimizing environmental, social and economic value of the work. So there is an option I’m going to talk about today, which is enhanced attenuation that can provide treatment of these very low concentrations and also can get rid of these ongoing costs and production of carbon dioxide, et cetera. So enhanced attenuation of PFAS, does that make sense? Because PFAS doesn’t biodegrade, right? So natural attenuation doesn’t just mean biological degradation. It’s also diffusion, it’s dispersion, blood lization, sorption, and abiotic degradation.

So what we’re wanting to do is take a natural attenuation process and enhance that, accelerate the effect of that. So what I’m gonna be talking about today is increasing the ability of the aquifer to absorb the PFAS, what we call retention, and that will then enhance the attenuation of the PFAS plume. There’s a really good paper on this by Chuck Neal called enhanced attenuation to manage PFAS plumes in groundwater. In this he looks at seven different techniques for enhancing attenuation of PFAS plumes, one of which is injection of particulate sorbents that I’m going to be talking about today. So you’re essentially injecting a sorbent into the subsurface and you’re slowing the movement of that contamination, the PFAS, through the groundwater dramatically. And what that does is it reduces the peak of the contamination discharging into a receptor.

So in an uncontrolled situation you’ve got the PFAS building up in the groundwater and hitting say a drinking well or a off-site surface water, something like that, and the flux is such that the concentration is above target levels. The idea behind enhanced attenuation is that you retain it in the subsurface, you slow the flux, you slow the movement of the contamination so that it doesn’t get above actionable levels and it keeps it essentially safe. So if we consider the PFAS source plume treatment, here we are on an airport, we’ve got a fire training area where they’ve been spraying the AFFF onto the area. It gets into the ground, it hangs up in those soils over time. it’s infiltrating because of precipitation down through the vedosome, touches the capillary fringe, touches the groundwater and starts to discharge very small amounts, but you only need small amounts to create these large plumes going off-site.

So what we’re going to do is talk about using something called colloidal activated carbon. So you probably know granular activated carbon from groundwater treatment, so that’s got a diameter of about a thousand micron. You might We’ve used powdered activated carbon for dealing with vapors that might have a diameter of anything from 50, say 250 micron. We’ve milled the activated carbon down to a diameter of about one to two micron. So that’s the size of a bacterium, that’s the size of a red blood cell. Then what we’ve done is suspended it in water using dispersion agents to create a liquid. It’s really like an ink-like liquid, and it’s a colloidal liquid. So it’s a suspension of particles.

The product names are Plume Stop, Source Stop. We also have one for Petrofix that we use for other purposes. And what you can do with this product is apply it into the source area and apply it as a barrier as well to deal with the source and the plume. And more specifically, you can go into the Vado zone. And what you’re doing is you’re looking at reducing the leachability of that contamination that is stuck to the soils so that it’s not moving, it’s not discharging into the groundwater. You can then go down to the capillary fringe. Now, obviously, the PFAS is surface activated so it likes to hang around at the air-water interface. So if you inject along the capillary fringe, you can prevent further discharge into the groundwater. You can inject the higher concentrations in the source area, so treating the groundwater at that location.

And at that point, you are then hugely reducing the amount of contamination getting into the groundwater and that allows the downgradient plume to attenuate. If you then have an offsite liability or a receptor just immediately offsite, then you can put in a plume stop barrier at that location as well and basically shut the gate, prevent any further contamination going offsite and allow that attenuation to occur under the site itself. So we’ve done this on 41 sites, I believe, so far. It might be 42, 43 sites, but it’s around about there right now. In the US, Canada, UK, Norway, Sweden, Middle East and Australia, we have a number of case studies. There’s a number of third-party papers on there and we can provide all of these. Our website’s a good place to go to, to look at that.

I’m mentioning that because I’m not focusing on performance today. We’re looking at sustainability, But just to touch on performance, there’s a paper by Grant Carey and the University of Waterloo on the longevity of treatment using colloidal activated carbon. They looked at 17 sites with data rule for 0.3 to 6 years, and they found that out of 16 sites that have data, one seemed to be an inappropriate technology. Essentially, it was used in a landfill or too close to a landfill and what there was was huge amounts of organic material coming off that so it was essentially swamping the potential barrier so it wasn’t the technology for that location.

Other sites were getting between 82 and 99 reduction essentially getting down to non-detect of the PFAS moving beyond the barrier itself. So it’s a really interesting read. If we dial in a bit closer to the site where I’m talking about today there’s a PFAS contaminated site it’s an international airport in the UK. They wanted to reduce their off-site liability. We’ve done a pilot study on that site and you can see that we got down to very low concentrations that we then maintained for nine months which was the length of the pilot study and we then took that on to a full-scale treatment which was injected and we finished in February of this year and we’ve and getting good results since then.

So there’s case studies on that that we can provide. We’ve got other things. If you wanna email me on that for more information, that’s absolutely fine to do that and I can provide what we have.

Okay, so we know it works, but how sustainable is it? So in theory, it should be sustainable, right? This is what we’re telling ourselves. It’s in situ, so it must be good. We’ve got low disruption. We come to site for a very short amount of time. We just do the injection work. We’re only using a little rig. We’re not leaving any pumping equipment on site. We’re not having to keep going back to site. It’s really low-maintenance passive approach. It must be sustainable, right? But we have to get quantitative about this. In the world that we’re in now and in developing, we have to look at the carbon for a pin of what we’re doing and prove what we’re saying.

So what we decided to do was have a third-party study. So we approached Rambol to do a study for us on this particular site. So we worked with the Head of Circular Solutions and Climate Specialist team in Finland. This is the site on the right. I’ve blurred it out because I believe that firefighters for airports can recognize each other’s airports based on the shape of the pretend plane that they put out. So we have to kind of blur it out so you can’t tell which airport it is. But essentially this is a plan view that the green area on the left and to the top is basically the grass of the airport itself. The groundwater is coming from top left to bottom right. As it passes under the fire training area, which is in the gray, all the drains there are leaking. The interceptor is leaking. So the foam has gone down into there and it’s getting then into the groundwater. The groundwater picks that contamination up and then moves over the site boundary. And you can see the darker green to the bottom right there. That’s called defensive planting.

Basically, it’s a lot of bushes going up the hill, et cetera, to prevent entry into the airport. That’s a steep slope. And we’ve got a spring line in that slope. So the groundwater is moving quite quickly through a gravel. It then picks up the PFAS, comes out of the spring line, and we’ve got PFAS in surface water heading down into a stream. So what we wanted to do was compare the lifecycle analysis for the institutes option and retention barrier that we have installed on the site. And then compare it to the equivalent pump and treat system that could have been put in place. And it was considered putting a pump and treat system in place on this site. So we did a lifecycle inventory analysis on the barrier itself. So on the right there, you can see we injected a barrier in a line. And over seven weeks, I think, we injected Plum Stop into the ground over 120 yards, 102 injection points.

So we had an injection rig, a direct push rig, just moving along the site, injecting the product into the ground. And we would then go along and just check that we were getting overlapping radius of influence so that we didn’t have any holes in the barrier. And we were then treating the contamination and allowing that groundwater to flow through. Once that’s in place, essentially you’re off site, and there is just validation monitoring to be completed twice a year for however long we need to keep going. So we designed it for a minimum of 15 years. It’s very likely to last much longer and the source is going to be dealt with as well, so that will help too. So there’s the cross-section version of that barrier as well.

So looking at the lifecycle analysis of that then, We used the Gabby 10 professional software to do the life cycle analysis using data from Sphere and EcoInvent and to the ISO standards above there. So the boundaries that we picked were cradle to grave. Now often for a product you’ll pick cradle to gate. So that is the upstream product, the manufacturing process, and then basically on the shelf ready to buy. It’s at the gate of the factory ready to buy. What we want to do is the grave as well, because it’s brought to site, there are activities involved with putting it in the ground, so the truer study is cradle to grave.

So what we looked at here is the raw materials, the activated carbon that we get from the supplier, bring that to our manufacturing facility, we mill that down to the right size, we suspend that in water as a liquid, and then at this point for the US, it would then to site but in the middle there you can see we’re transporting it by ship across to the UK, it goes into our stores and then when we’re ready to do this site it was delivered to site and then it’s injected into the ground using direct push rig. At that point there’s no operation and maintenance and there is just monitoring and the end of life there is waste and there is no waste material, there’s nothing coming to the surface. Essentially the waste are the pallets and the rums from the product itself, but nothing in terms of the PFAS coming to the surface.

So we then designed an alternative pump-and-treat system. So this was based on three pump-and-treat designers put this together, or it was a consensus between three different pump-and-treat designs. The idea is that we’re putting in extraction wells, and it’s operating over 15 years of the study with a 95% uptime. You’ll notice there’s a lot of wells there, And the idea is because it’s fairly fast groundwater and we want to reduce the amount of drawdown. We don’t want to create any vertical smear. So we’ve got a high number of closer wells. And basically, we’re pumping out from that. It’s running through a granular activated carbon system. And we’ve got operation and maintenance going on for the 15 years, as well as the same amount of validation monitoring.

So there’s the cross-section there as well. So then if we look at the pump and treat system, similarly cradle to grave, so we’ve got the raw materials going into making the equipment, we didn’t assume that they were all used up in terms of the containers and things they could have a life beyond the end of the project, etc. So they are manufactured into the pumps, the pipes, the tanks, brought to site, they’re installed along with the extraction wells, transfer lines, etc. So you install the system, get the system going and then once it’s going you’ve got 15 years of the operation and maintenance which involves electricity to keep the system running and that’s running of fuel.

You’ve then got operation and maintenance in terms of the pumps will wear out so they’ll need to be replaced so you have somebody coming to site and doing a number of site visits so whereas normal monitoring would be 90 visits over the 15 years here we’re looking at something like 600 visits because you’re going back and making sure the system is running. And then you’ve got waste management as well. It’s going through granular activated carbon. The granular activated carbon becomes spent and you have to then get rid of that and you’ve got waste water as well. So that granular activated carbon is assumed to be going to landfill in this scenario. And there’s the equivalent of the flim stop that I mentioned before.

So, looking at the carbon footprint first, the results are that the in-situ retention using plume stop is using more than 98% less carbon. So we’re looking at nearly 4 ,000 tons of CO2 equivalent for the pump and treat system, and it’s about 56 tons equivalent over the 15 years for the plume stop barrier itself. So that’s about 70% smaller carbon footprint. Now we’ve broken that down so we can see where the different impacts are. You can see at the bottom there the total carbon footprint, 56 versus 3 ,922. And there’s different areas there where the pump and treat system is using more electricity, it’s producing waste, et cetera. But one of the key things is the granular activated carbon is the most significant impact there. So this is assuming it’s going to landfill.

I mean, we’re already seeing that landfills are starting to not accept this. And that is because the contamination may last longer than the landfill itself. So you’re just gonna create another source of contamination in the subsurface. So you’re probably looking at incineration in the future. So this might make this line in the life cycle analysis worse. So what is the option to reduce or remove the granular activated carbon? So we looked at this as well. We thought about taking away the granular activated carbon main filters and using form fractionation. So for those of you who haven’t used form fractionation or haven’t come across it, but basically you are bubbling through the contaminated water. And because PFAS is surface activated, it essentially sticks to the edges of the bubbles. You bring that out and you can skim that off. And we’ve left in a little bit of granular activated carbon at the end as a polishing phase, but you’re reducing hugely the amount of granular activated carbon, but you are increasing the electricity use.

So if we look at that, instead of being 98.5% lower, we’re now 97.5 lower. So instead of being 70% smaller carbon footprint, the plume stock barrier is now 40. So it’s making a difference, but you’re not in the same ballpark. You’re still two orders of magnitude higher by doing an extractive treatment. So essentially, changing the treatment is not having a significant reduction in that carbon footprint. So if you look into the figures, the pumping alone, so the pumping the water out, is one or two orders of magnitude higher than the passive in situ system alone. So once you pumped it out, if you then treat, you’re only really adding carbon footprint to this. So looking at the lifecycle cost analysis, Again, done by Ramboll over a 15-year period.

There are costs at different times throughout. So in terms of an in situ barrier, there’s a lot more upfront costs because you are coming in doing it all in one go. The pump and treat system, there is upfront costs installing it, but then there are operational costs over time. So what you have to do is roll that back to net present value. So essentially what are those future costs as if you paid for them all now? And that allows you to compare different approaches that happen with costs at different times, okay? So basically the plume stock barrier was 1.6 million compared to pumpetry with granular activated carbon of 4 million versus 4.6 million. So the in situ approach is 61 to 65% less in terms of life cycle cost analysis. If we then look at other factors, so we’re looking at the sustainable assessment scoring, What Ramboll have is something called their SURE model.

It’s a tier two sustainable assessment. You can see that my animation’s got ahead of me a little bit, so you’ve seen the results. But what it is basically, it’s based on the standards of ISO and ASTM and also SURF UK guidance. And it’s a linear additive multi-criteria analysis method designed to incorporate both qualitative and quantitative information. So what does that mean? It basically means that you get some experts together. They think of sustainability indicators for each of the domains, environment, society, and economy. Some of these can be qualitative, some of them can be semi-quantitative, and what you’re trying to do is create a quantitative score. So for each of those domains, you’ve got five indicators.

You then give them weighting as to how important they are, and then you score the plume stop versus the granular activated carbon versus the foam fractionation, and come out with quantitative sustainability assessment. 100 is the ideal and what we’re seeing is the in situ barrier has a score of 84 versus 43 for the others and is generally better in all three of the domains. So in conclusion, remediation of PFAS site should consider sustainability for every site. There’s just so many of these sites that you have to consider the bigger picture than just the site you’re looking at. We’re on a site in Scandinavia in the middle of nowhere.

Should we really throw huge amounts of energy at this, given that we shouldn’t be producing, we shouldn’t be adding more carbon dioxide at a time where, as a species, we’re supposed to be trying to reduce that impact? So by doing sustainability studies on what remediation approach you need to use, you can then ensure that your site is not being managed in isolation. Pumper tree is a much higher carbon footprint for both of the components pump and treat. So pumping alone is much higher impact than in-situ passive treatment, so any in-situ treatment on top of that will increase the impact. So enhanced attenuation of PFAS through retention using colloidal activated carbon is an effective and sustainable approach to address a global pollution issue. And that’s me.