The Need for Sustainable PFAS Remediation: A Lifecycle Study by Ramboll Comparing the Environmental Impact of In-Situ Sequestration to Pump and Treat

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Today’s presentation will discuss the need for sustainable PFAS remediation, comparing the environmental impact of in-situ sequestration to pump and treat. With that, I’d like to introduce our presenters for today. We’re pleased to have with us Yarno Leighton, Head of the Department for Climate and Circular economy at Ramble. Jarno Laitinen currently works with topics related to resource management and climate impacts. In his various roles at Ramble, Jarno has acted as the head of sustainability, led global sustainable remediation programs, and promoted leadership in sustainability through various projects, publications, and speeches.

We’re also pleased to have with us today, Gareth Leonard, managing director of Regenesis in Europe. In his current role, 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 20 years, having provided successful remediation designs and implementation for over 1 ,000 projects across Europe, the Middle East, and Africa. All right. That concludes our introduction. So now I will hand things over to Gareth Leonard to get us started.

Hello, everyone. My name is Gareth Leonard. I’m the Managing Director of Regenesis at Europe. Gives me great pleasure to be given this presentation with Jarno. I’m going to set the scene over the next few slides, essentially what the issue is that we’re trying to address. I’ll talk about the technology that we’ll be talking about today then introduce the site on which a life cycle analysis and sustainability study has been completed and then I’ll hand that over to Janu who will take you through the methodology and the results that came from that. So we’re talking about the need for sustainable PFAS remediation and we’re comparing the environmental impact of in situ sequestration to pump and trade.

Okay so Per and polyfluoroalkyl substances PFAS. I want to go through on this slide what are the attributes that make them such a problem essentially and the first thing is that they’re just incredibly useful. So they are omniphobic which means they’re really good at waterproofing and oil proofing so they’ve got all sorts of for coating in commercial and domestic settings. They’re also good for aqueous film forming foams, which I’m sure you’ve seen for putting out fires. Now this makes them a contaminant that we have actively sprayed onto the ground on thousands of sites for decades now. So there’s not many other contaminants we’ve done that, arguably you know petrol filling stations with the filling up we drip some oil, but this is very much intentionally putting this foam, this contaminant, onto the ground. So once it’s on the ground, the contamination the PFAS soaps to these soils, often in the upper part of the Vado zone, where it provides a reservoir of contamination for many, many decades.

Now as more foam is put on top or rainfall enters the ground and infiltrates the Vado zone, you get leaching of this contamination. It moves vertically through the formation. And then when it touches the groundwater, PFAS is very mobile in groundwater. So it starts to move down gradient. It’s recalcitrant to degradation. It doesn’t really biologically degrade past a certain point. It doesn’t really chemically oxidize. So it just keeps on going. And it’s toxic at very low concentrations. Certainly, the longer chain PFAS compounds are toxic at very low concentrations. And so what you end up with is these very large, very dilute plumes that are still driving a risk. So the result is that PFAS are essentially everywhere.

This is a map from Le Monde newspaper. It’s the Forever Pollution map. You can go, I’ll put a link at the bottom there, and you can go and have a look. It’s interactive. Very interesting. So it’s a number of theoretical sites with known contamination or presumptive contamination. There’s also a version of this in the US that have taken a different approach. It’s in environmental health news where there’s about 57 ,000 sites that have suggested are in the US. So you’re looking at tens of thousands of sites here which is a huge amount of sites we need to clean up which we’ve only just started dealing with. So if you think about all the remediation that we’ve done in the past and all the contaminants we’re dealing with now, this is a whole extra area that we need to deal with.

So how can we treat PFAS? As remediation professionals, we tend to revert to removal and destruction. So these are different approaches that you can take for that. So the treatment efficiency is on the y-axis, the higher up, the better, against contaminant concentration increasing along the x-axis. So if you were, say, treating a petrol filling station, you might have free-phase fuel. So you start with physical extraction of that. That becomes inefficient once you get rid of the easily removed floating contamination. So you move to chemical oxidation, and then you want to get to low targets. So you then move to biological degradation to get you there.

Well, with PFAS, we don’t think there is any biological degradation, certainly at this point. It’s recalcitrant to chemical destruction as well. So you’re left with physical removal of the contamination. Now, physical removal of the contamination’s very effective at high concentrations, but PFAS exists in very low concentration. Nanograms per litre is still driving a risk. Some targets are looking at picograms per litre. So the result is that it’s an inefficient way of removing the contamination. you’re pumping a lot of water to get a small amount of contamination, you’re going through a lot of granular activated carbon, there’s a lot of energy, equipment’s running out, and ongoing costs. And of course, all of this has a carbon footprint.

So we’re looking at trying to deal with a global issue, and we’re potentially going to increase our carbon footprint as an industry, as cleaning up contamination and that might exacerbate another challenge to the globe which of course is climate change. So how are we going to deal with one global issue without exacerbating another one? So one way we can do it is look at the sustainability of the potential remedial approaches we are considering for PFAS. So by doing a sustainability assessment, and by doing a life cycle analysis of the options, it means that you’re not looking at your site in isolation. You’re looking at the effects of the remediation that you’re doing, not just at whether it’s successful, not just at whether the cost of it, but what is the wider impact on the globe of what you’re doing on this site.

So sustainable remediation is defined by ISO 18504 the elimination of control of risks whilst optimizing the environmental, social and economic value of the work. So one approach that I’m going to talk about just now is enhanced attenuation which is able to deal with very low concentrations of PFAS and also has the potential to reduce the impacts, the carbon dioxide production, et cetera, that you would otherwise have from physical treatment. So enhanced attenuation of PFAS, what do I mean? PFAS doesn’t biologically degrade, but of course natural attenuation doesn’t just mean biological degradation. It’s also diffusion, dispersion, volatilization, sorption, and abiotic degradation. So what we wanna do is take a natural attenuation attribute and enhance that. and what we’re talking about today is looking at the ability of the aquifer to soar and ****** the PFAS contamination so that it increases the retention of that contamination, which enhances the attenuation of that PFAS plume.

So there’s a really good paper by Chuck Newell on this approach for PFAS. In that paper they consider seven different approaches for enhancing the attenuation of PFAS, one of which is the injection of particulate sorbents, which we’re gonna be talking about today. And essentially you’re putting a sorbent into the surface, you are sorbing the contamination that’s moving through, you’re slowing the movement of that contamination through the subsurface. And the effect is that the peak concentration that then gets to your downgradient receptor, whatever that might be, it might be a drinking water well, it might be a surface water stream, that never gets above an actionable level. So in an uncontrolled situation, you’ve got the contamination getting into the groundwater, it’s moving down and it’s discharging into your receptor at concentrations that are problematic. By putting a sorbent in, you are slowing the movement dramatically of the contamination through the subsurface so that that discharge into the receptor that never gets above the unsafe level.

So if we look at the remedial approach, if we consider the PFAS source plume system, what we’ve got here is an airport, a fire training ground on the airport, they’re spraying AFFF and practicing putting out fires, et cetera, it’s getting through the cracks, it’s getting onto the grass, it’s getting into the drainage system, it moves down through the vedosone, hangs up at the capillary fringe, dissolves into the ground water, and then you’ve got a plume that is then going off-site, causing off-site liability, maybe impacting the aquifer itself, getting into drinking water, surface water, et cetera. So the way we are considering treating it in this presentation today is using a colloidal activated carbon product. So it’s a liquid version of activated carbon. So you’ll have come across granular activated carbon in Brita filters at home or in pump and treat systems for treating water. That has particulate size of about a thousand micron in diameter generally.

Powdered activated carbon you might’ve come across. It’s got a diameter of about 50 to 250 micron scale and that is used for vapor treatment generally. What we’ve done here is we’ve milled the powdered activated carbon down to a diameter of about one to two micron. So that’s the size of a bacterium, that’s about the width of a red blood cell. We’ve then suspended that in water so you’ve got a colloidal liquid and the idea is that you inject that in low pressure into the subsurface, it spreads through the subsurface, it coats the aquifer and it changes the of the aquifer so that it retains that contamination. So it comes in several forms. We’ve got source stop for source areas, plume stop for plume barriers. We’ve got a petrol fix for petroleum hydrocarbons. So it’s used in the source area in the plume.

In the source area here, the first place would be targeting the soil in the vedosone, so that upper part of the vedosone. We’ll be using the colloidal activated carbon product source stop, we’ll also probably be using powdered activated carbon as well. And what we’re doing here is the contamination has already sorbed to the soils. We’re binding that more tightly so that we reduce the leachability of the contamination from the soil. So that prevents any further contamination coming off those soils and discharging into the groundwater. At the capillary fringe, because PFAS is surface activated, it tends to stick to the surfaces of the water where you’ve got a mix of air and water. So you get contamination hanging over the capillary fringe. We can put it in a horizontal barrier at that point. It’ll absorb that contamination, prevent it dissolving into the groundwater, catch any residual contamination coming from above. We can inject it into the groundwater at the head of the plume, just absorb that contamination, prevent it from migrating any further. And at that point, that might be enough. For a lot of PFAS sites, that might be all you need to do. And then you allow the enhanced attenuation of the downgradient plume to occur.

If however you’re in a sensitive area or you’ve got a receptor immediately adjacent site or a legal responsibility to prevent contamination coming from the site you can also inject the product as a barrier at the edge of the site as well and that allows the groundwater to move through but prevents the contamination from moving any So we’ve used this on 41 sites so far across North America, in the UK, Scandinavia, Middle East and Australia. We’ve got a lot of case studies on our websites which we can provide, but I just wanted to reference a nice paper by Grant Carey and the University of Waterloo where they’ve gone and looked at multiple sites and pulled the data together, worked out longevity. It’s a good read. So there’s data on 16 sites up to about six years. One of those sites was the inappropriate technology that we started a pilot study, essentially, in an uncontrolled landfill. So the DOC was so huge, it was swamped. So we didn’t take that any further. But of the other sites, we’re getting about 82 to greater than 99% reduction in the PFAS concentrations, which is then maintained for a very long time. So an interesting read, that paper.

So a site that we’ve done in the UK, and one that forms the study that we’re talking about today, is an airport in the UK. The picture on the right, I’ve blurred out, because firefighters can recognize each other’s airports by the, whatever they call it, the fake aeroplane that they put out the fires on. So you have to blur it out so they don’t recognize each other’s airports. But basically the light green is the airport and you’ve got the groundwater flowing from top left to bottom right. The darker green in the bottom right is offsite. That’s actually a hill going down to a river and it’s darker because it’s got defensive planting, lots of thorny bushes all the way down that slope. And what happens is the groundwater’s moving through, made ground alluvium, and mostly the River Terrace gravels sitting on top of a London clay. As it gets to the fire training ground, the grey area there, all of the drains have got PFAS in them from the AFFF and the interceptor is leaking there as well. So the groundwater is picking up that contamination and taking it off the edge of the site. There’s a spring line down the hill from the site and PFAS is being picked up in that spring. So basically the PFAS is then impacting surface water. So it’s a voluntary remediation to remove the off-site liability.

They wanted us to come in and stop the contamination coming off the site and then what’s going to happen next is they’re going to go in, replace all the drainage, remove those soils, we’ll apply product in there well and remove that source as well. So we’ve completed a plume stop barrier on the edge of this site. At the edge of this site we it’s a 120 meter long barrier that basically creates this subsurface filter, prevents the PFAS from going any further. That’s what it looks like in cross-section. And what we did is we did the first 15 meters or so of the barrier as a pilot study. We then monitored for nine months and showed that we got down to almost non-detect for the PFAS. And then once we were happy that it was working, we then continued the barrier on and completed the full treatment. That was finished in February of this year and it’s continuing to work.

So having done the work, we know it works, but increasingly we need to consider, which is the reason we’re here talking about this today, the sustainability of these approaches. And I’ve done in situ remediation for a long time, so I’m biased. I look at it and I think, OK, we must be more sustainable, right? We’re just coming to site for a short amount of time. We inject something in the ground, and then there’s no energy used. There’s nothing come to the surface. It feels like we should be more sustainable. But we’re at a point where we have to get better than that for all contaminants, but particularly for PFAS. How are we going to tackle all of this contamination without quantifying how sustainable our options are? So we decided to take this real site, this full-scale treatment, and do a sustainability study on it. But what we needed was professional help. And that, of course, is where Jarno and Ramboll come in. So I will hand over to Jarno now.

Thank you very much. My name is Jarro Laitinen. I work as head of department for circularity and climate in Ramboll here in Finland. I’m very happy to be here to talk about sustainability and very happy that we’ve been able to work with Regenesis, one of the forefront companies actually supporting sustainable remediation, in understanding better where the environmental impacts on remediation projects originate and to quantify those.

I’m going to present today a study on the sustainable remediation where the aim was to compare three alternatives for in situ and exit remediation for PFAS contaminated groundwater. The case site was presented in the previous presentation but I’ll give more in-depth information into the remedial alternatives that were compared in the upcoming slides. This study was in fact a complementary to previous LCA work that life cycle assessment work that we did on Regenesis remediation products and it’s actually involving a real life remediation site. Since the site in question is already undergoing remediation, this is a comparative assessment where we are doing this kind of a best practice designs for that we are using as alternatives to compare with. And the best practice designs and alternative, remedial alternatives are pump and treat, where in the first alternative, the groundwater is filtered with normal granular activated carbon. And then the second alternative is aiming to lower the environmental footprint that comes with the use and discarding of the activated carbon by adding a separate stage of foam fractionation to the pump and treat solution.

I have to highlight that the study did not focus on the remedial option surprise or technical efficiency of the selected methods, they were designed to fulfill the same remedial goals. And all designs for these were done at a general level. So when, for example, designing the pump entry, we did not include all the valves and fittings and everything. So it is, in that sense, not a fully complete study of everything, but at a level that gives enough data to draw conclusions upon.

So to start with what is sustainable remediation and if we follow the ISO standard on sustainable remediation it is defined as the elimination and or control of any acceptable risks in a safe and timely manner while optimizing the environmental social and economic value of the Well what this actually means if we think about contaminated site remediation. I have here a simple graph showing a site where we have contamination shown on the orange line and that causes a certain impact on the environment. Now as we start remediating the site towards the compliance level, the contamination decreases and the impact is decreased as well. But all actions that we take on the site, they introduce impacts then on the economy, then on the environment, and also on the society.

So if we sum up all the impacts from both the contamination and from the different sustainability angles and look at the sum impact, we can see that when we reach the remediation at the compliance level, we’ve actually reduced significant gains in our contamination, but only marginal gains in terms of sustainability. And when we talk about sustainable remediation, our aim is to find the balance point where The benefits from the remediation are in balance with the impacts that the work has on the society, environment and economy. But often we still tend to move towards very low threshold levels or unnecessary remediation even. And in those cases, I argue that we are actually not causing any benefits on sustainability, but in fact have negative impacts as an overall. So when we talk about sustainable remediation and think about how to measure sustainability in a project, first of all you have to understand that when we talk about sustainable remediation we’re moving from the pure risk management and remediation perspective into a more holistic way of optimizing the environmental, social and economic value that we gain from the project.

So in terms of sustainability, it’s not enough just to mitigate the negative input but at the same time create some positive inputs for the community or the ecological sustainability. And there isn’t really a one-stop shop for sustainability or sustainable remediation but this needs to be determined on a case-by-case basis. And the way how you can to determine sustainability, you have to have a process that’s systematic, it’s clearly documented, and you can clearly justify all the decisions that you’ve done during the process. So there are different tools that you can do to determine the sustainability.

Most frequently used tools are environmental risk analysis that is very well familiar to all of us working in environmental remediation, but other tools such that will be presented in this presentation include life cycle assessment, life cycle cost assessment, and multi-criteria analysis. And these different tools target different aspects of sustainability, whereas the life cycle assessment has a very specific environmental angle, and the life cycle cost assessment, an economic angle and the multi-criteria analysis as a more multifaceted approach looking also to the social and other environmental aspects. So if you want to have a thorough and full view on the sustainability you should use multiple tools in your assessment.

So following that I’m gonna present you how we looked through the sustainability assessment in this specific project. I’m going to walk through a carbon footprint assessment, a carbon handprint assessment, life cycle course assessment and then a multi-criteria sustainability assessment done with the Sure by Ramball assessment tool. But to start off I’m going to give a quick overview of the compared remediation methods. The previous presenter gave a very good overview of the first one, immobilization with colloidal activated carbon injection. This is a remediation method based on in situ sorption and retention of the contaminants. And since this approach was already applied on the site and it was based on the Regenesis product, PlumeStop, that was used as the basis for the assessment. The two alternatives, they were both based on pump and treat, which is a remediation method based on extraction of the contaminated water, sorption of the contaminants on a filter media, and then treating that filter XC2.

In our assessment, the filtration is based on activated, granular activated carbon, which is the most common adsorbent, and a bituminous cobalt-based activated carbon was used in the assessment, as that’s what the majority of systems globally use. And that’s also one of the better activated carbons for PFAS adsorption likewise. In the assessment, the spent activated carbon was assumed to be disposed of site for land filling. In the third alternative, a separate step of foam fractionation was added, and the aim of adding the foam fractionation was reduce the amount of carbon used in the filtration process. This I will show later what the quantities are that we assume for the reductions, but in addition to coal then of course the foam fractionation produces an additional waste stream from the PFAS foam. And both the PFAS foam and spent cac were assumed to be disposed either to thermal destruction or in this case landfill.

First, I’m going to move you through the carbon footprint assessment and to start off what is a carbon footprint? It’s also known as the greenhouse gas emission assessment. The aim is to evaluate total greenhouse gas emissions and express those as carbon dioxide emissions equivalents. The greenhouse gas assessment or the carbon footprint assessment is a subset of life cycle assessment. The main difference here is that whereas the greenhouse gas assessment looks only to one environmental impact category being the greenhouse gas emissions, the life cycle assessment takes into account more environmental impact assessment categories like the land use or water use, acidification and eutrophication. In addition to doing the carbon footprint assessment in this project.

As I said in the beginning, this project was a follow-up on a work that where we also did product level life cycle assessment for region assist bloom stop products. These results were also used in the assessment, but they’re not introduced or included in this presentation. In general, a life cycle assessment or a carbon footprint assessment follows four stages. You first define the goal and scope of the assessment, then you do a lifecycle inventory, which means that you look at all the inflows and outflows within the system that might generate emissions. Then in the lifecycle impact assessment, you calculate the emissions and you quantify those, and then in the final interpretations that you make your conclusions based on the assessment. As noted, we had three different scenarios that we were looking in this, or the alternatives. We had the plume stop alternative, the pump and treat with gap filtration, and pump and treat with bow fractioning. We will be further than referring to these with very short acronyms, so I hope that you take note of what the alternatives are.

When doing the life cycle assessment and the greenhouse gas assessment, we took note that the lab site is located in the UK, so we were using localized data for any production and use, and we had a cradle-to-brave approach for all of this, so taking all the production steps from creation of materials, their final use or discard. And the reference time frame in this assessment for all alternatives for 15 years. Our baseline assumption was that most of the benefits would be achieved within this time frame. And the functional unit that what we were targeting to calculate was the tons of carbon dioxide equivalents generated during this whole 15 years time frame from cradle to grave for all of these alternatives.

Then I’m going to show you quickly the system boundary and the scope of the assessment. So when we talk about cradle-to-brave framing, we start from the raw materials acquisition and end up in the end of life for those products. In the middle, there’s everything from transport, manufacture of the products, transport to remediation site, any installation works, operations and maintenance during remediation, monitoring, and finally the end of life. For the colloidal activated carbon, what was included in the system boundary was first of all the Plumestop product level LCA that we did separately, and to that we amended in the greenhouse gas assessment any transportation to the specific project site any injection works that were needed and any monitoring for the 15 year time frame for the project.

It’s worthwhile to know that there’s no operation or maintenance in this alternative as we move to the two other alternatives on the pump and treat, where first of all, the manufacturing of the equipment was included, manufacturing all the extraction wells, pumping wells, monitoring wells, transfer lines. The transport of all of those equipment to the site, most of them were manufactured and transported locally. Then the civil works needed for the installation, and then the continuous operation and maintenance for the 15 years timeframe that the assessment was made to consider, including all the energy consumptions, the materials used, any maintenance work required. And also then the monitoring and as an end of life the waste management where the spent granular activated carbon plays a significant role.

Looking into the life cycle inventory analysis, so this is where we quantify any materials used, any energies we use, any wastes we product and any emissions that we create. Ramboll did a design for all the pump-and-treat equipment used within the remediation and the basic design for the colloidal activated carbon installation was based on the real-life installation that was introduced in the previous presentation. Well then, going deeper into the lifecycle inventory analysis, this slide shows the key system variables between these alternatives. And if we look first and foremost for the colloidal activated carbon injection, here on the right, you can see the same diagram that was shown. The solution is based on a single injection round. Blooms the barrier is being created perpendicular to the ground water flow. It consists of 102 injection points and the 33 plus tons of colloidal activated carbon, the plume stock product. And for the injection works, other works, 1600 liters of fuel is expected to be spent and three monitoring wells are to be installed on site and there will be a continuous monitoring for the 15 years, two times a year.

Well, if we compare this then with the pump and treat alternative, again diagram shown on the right, this consists of a fixed equipment installation that are expected to be in a continuous operation for 15 years, eight separate extraction wells are assumed to cover the groundwater flux zone and likewise as in the first alternative three monitoring wells. There’s a little bit more fuel consumption, 2003 liters for the installation. Of course the environmental footprint of the remediation equipment from the operation that was expected to be at 95% uptime with a constant groundwater pumping rate and we were assuming 24 tons per year of granular activated carbon use and 64 megawatt hours a year electricity consumption. And in addition to the environmental monitoring, which was assumed like the like with the colloidal carbon alternative we were assuming four times a year operational and maintenance inspection from a nearby city.

So then if we look at the third alternative where in addition to the gap filtration we have a full fractionation included. The key difference with that is being that we have reduced the activated carbon use to approximately one So, to 8.5 tonnes a year, but at the same time, we’ve doubled the electricity consumption to the requirements in the energy requirements that the foam fractionation has. This is the simple diagram of the lifecycle inventory scope that we had for both the pump and treat, and with the pump and treat with the foam fractionation add-on included. Then, I want to touch a bit on one of the key variables in the assessment. Very early on in the assessment, it was noted that the granular activated carbon use is playing a significant role in the overall assessment. There is, based on the study that we did, There’s a high variability in what kind of loading capacities or breakthrough times there are for long and short-chain PFAS for different activated carbon types. But based on all the studies, the coal-based activated carbon is what most filter systems globally use, and they’ve shown very good results in the PFAS reductions.

So, the idea was that the pump and treat filters are this kind of packed flow through vessels and they are operated in a lead-lack configuration, so this would minimise any breakthrough through the system. And if the foam fractionation step would be included, as in the alternative three, then it was assumed that the activated carbon would only be used as a polishing step and as a management step. In general spent activated carbon can be thermally reactivated but there’s no one really providing that service for PFAS and hence it was assumed that the activated carbon is of virgin nature and it will be disposed to landfilling after use. So then a few statistics for those who are interested in dimensioning activated carbon or are knowing more in depth about those.

According to literature, the PFAS removal efficiencies for activated carbon are up to 99%. And the absorption capacity has a very high variability, as said, from 10 to 1 ,000 milligrams per kilo. But this is always very much case-specific. So depending on the water source, what is the PFAS specification, how much other TOC or DOC there is on the groundwater or co-contaminants, the adsorption capacity can vary a lot. And also the typical filter empty bed contact times vary very much from 10 to 30 minutes, and the breakthrough, so how long it takes for the filter bed to be thoroughly absorbed and the contaminants to start leaching through is from anywhere from 100 to 20 ,000 bed volumes treated. So in the right side table you can see the figures that we decided to use on the assessment and these are now in the low end of the variation range that was identified.

We really wanted to be conservative in our assumptions in how much carbon would be used that we wouldn’t be overestimating that for the pump and treat systems. So for example if the typical breakthrough according to literature occurs for pump and treat with carbon from everywhere from 100 to 20 000 bed volumes, we were using only 1000 bed volumes as our basis. And from these tons per year. Then we were also trying to identify any limitations that our study might have and just going to highlight a few of the high and medium level concerns that were noted. The high ones are especially in the use of the activated carbon whether it is for the pump and treat or for the colloidal activated carbon injections. These are always case specific. Even for the colloidal activated carbon there isn’t many references sites with 15 plus years of monitoring data to be used as statistics. Then a few of the medium level assumptions and limitations that I could flag.

One of the interesting things that we noted is that, for example, laboratory analysis, we don’t have any information about the environmental footprint of those. So assuming a site remediation where samples will be taken for 15 years, the total sample amount can amass to anything up to 1000 plus assessment. And if those will be then sent with an airplane across Europe and will have its own impact likewise. So now that we’ve collected all the data from the life cycle inventory we started doing the life cycle impact assessment and we do this as looking at the global warming potential and quantify that as the carbon dioxide equivalence. This means that we put all the different greenhouse gases that come whether they’re carbon dioxide or methane or nitrous oxides, we quantify those as CO2 equivalents and there we have different global warming potential factors that are used to scale those different coal greenhouse gases.

We did the calculations with an LCA tool, Gabi, provided biosphere. Next we will then move to the results. So for the three alternatives total for the 15 years operations how many metric tons of CO2 equivalent were generated is shown on this graph and as you can see bloom stop has a very small carbon footprint compared to the pump and treat the granular activated carbon or with foam fractionation. This diagram separates the emissions to the remediation equipment, civil works, the remediation and operation stage, maintenance, monitoring and waste management. As you can see for the pump and treat alternatives as also with bloom stop. The most significant environmental impacts in terms of the carbon footprint come from the remediation and operations that includes any consumables like the bloom stop or granular activated carbon use or the electricity. The other significant category is the waste management that includes any off-site treatment of these hazardous wastes like the spent gag, the PFAS foam, or the waste water from the pump and treat effluents.

All the other categories in this scale seem quite minor. But if we look at this in a table format in a bit more detail, we can notice that even thought whether we’re using in the operations where there is a direct injection of colloidal activated carbon or using granular activated carbon in the filtration step, there is a significant difference. But already when we are introducing a remediation system that has equipment built and installed on stage, those have a significant environmental footprint. Likewise the electricity needed for operating them, the maintenance and other aspects. And always when we have an alternative where we have some ex situ hazardous waste that we need to dispose or treat, we have to take into account the environmental footprint from those as well.

So even though the materials that we use for the remediation have a significant environmental footprint. Also everything that happens before we start the remediation and then at the lower in the value chain of the remediation site. Well as the figures are very large and we noted that that we want to do some sensitivity analysis especially in terms of the gap use. So we made an assessment looking into what if we would assume that the carbon use would be at the low end of all the values that we found from the literature, or then at the high end of all the values. And we came into this kind of a range with the GAC use. So that would mean that the total carbon footprint of the pump and treat with activated carbon, for example, could be anything from 1 ,400 metric tons to 7 ,000 metric tons. Still significantly higher than with the plume stop, but possibly the difference would be much more marginal in comparison with the foam fractionation if both values for the GAC use were at the low end.

Well then about carbon handprint assessment. Carbon handprint is a way of comparing the potential carbon emissions or CO2 equivalent emission savings while comparing one method to another. So you always have a baseline method and as the baseline method we were using the pump and treat with colloidal with the pump and treat with granular activated carbon and comparing that against the immobilization or with the pump and treat with foam fractionation. We can see that if we use the in situ immobilization the plume stop alternative Instead of having a pump and treat with GAC, we are saving 3 ,867 tons of carbon emissions. Or if we are using that instead of the pump and treat with foam fractionation, we’re saving over 2 ,000 tons of CO2-equivalent emissions. If we are using the pump and treat with bone fractionation and comparing that against the pump and treat with CAG filtration, we are also saving 1 ,700 tons of CO2 equivalent emissions. So finding a more environmental alternative in terms of the carbon footprint can help you generate a significant carbon handprint for your project.

So a few conclusions. The results are case and site specific. And we had to do some assumptions in setting the stage. There is a clear impact that we can identify based on this assessment. And those are that the immobilization with the colloidal activated carbon had a 40 to 60 times smaller carbon footprint for PFAS remediation in CO2 equivalent emissions compared to the pump and treat based remediation alternatives. This is one to two orders of magnitude so it’s a very significant difference. So big that it really precludes any significant changes to the result even though we do any adjustments to the assumptions and uncertainties. The biggest stages having the largest individual impact, the carbon footprint were with the remediation operation ranging from 70 to 80% and with the waste management with an impact from 20 to 30%.

And it’s worthwhile to note that the most significant life cycle inventory factor affecting the carbon footprint was related to the activated carbon use in all three remediation methods. The carbon footprint, say the break even for the plume stop alternative over the pump and treat based alternatives, occurs already after 2.1 months of operation. So for the similar carbon footprint, you could do a re-installation of this kind colloidal activated carbon every two and five months. Well then I will move quickly to that life cycle cost assessment before moving to the sustainability assessment. The life cycle cost assessment is a way to compare alternatives on a monetary terms. In our assessment we were using the net present value as the metric. The net present value included in our assessment, the initial CAPEX for all the remediation and equipment and civil works, the future operating expenditure, there was any material inputs, any operations, maintenance, monitoring, the waste management cost. And we didn’t calculate any residual value for any of the equipment.

So for example the pump and treat equipment might have some value in the secondary use, so very minimal after the 15-year time frame. And the study period was similar to the greenhouse gas assessment, it was 15 years. And as we are using this kind of a net present value calculation, we need a discount rate to discount all the future costs to present day value. And we were using a 3% discount rate. And if we look at the cost breakdown in net present value for the 15 years of operation, the most significant costs for all of these originate from the remediation and equipment. So this includes all the colloidal activated carbon material, its application, the pump-and-treat equipment, and so forth.

But if we look at where the differences then come between the alternatives, especially for the pump-and-treat with activated carbon and foam fractionation, we can see that for the pump-and-treat alternatives, there are significant costs in the operation phase included to any replacements, the operations, maintenance, monitoring, and the waste management. So this comes from the annual replacements of the granular activated carbon, four times a year site visits, changing of the pumps, fixing of the vessels and the waste management of both the granular activated carbon, the separated PFAS foam and the waste water that’s discharged from the system.

Again, if we look at this in a table format, we can see that even though the equipment and the installation costs are quite similar, ranging from 1.2 to 1.8 million euros, there is significantly higher civil work costs for the pump and treat alternatives as they need fixed installations, and also for the replacements, O &M monitoring, and so forth. So if we look at the unit costs that is shown on the bottom, per euros, there should be a cubic meter, not a square meter treated. For the colloidal activated carbon, in this assumption, it’s 2 euros per cubic meter treated, whereas for the pump and treat with granular activated carbon it’s 4.9 and for the pump and treat with bone fractionation it was assumed to be 5.7 euros per cubic meter.

And for those who are not, who want to see also the undiscounted value, not only the net present value, on the bottom line we show also the total cost of ownership in an undiscounted value. So we’re not discounting future money is to net present value. So in that alternative the difference seems even larger as most of the investments come already at an early stage for all of these alternatives. So whereas the undiscounted value for the in-situ colloidal activated carbon would be in 1.5 million euros, it would be for pump and trade 5.7 and for pump and trade with pump fractionation 6.2 million euros.

So the conclusions, the immobilization with colloidal activated carbon had 60 to 65 percent smaller total cost of ownership in terms of net percent value. The largest differences in the total cost of ownership, they come from the capital expenditure from the installation of the system, replacements of granular activated carbon, use of electricity, operation maintenance, monitoring and waste management. And if we look at the break even, the financial break even in terms of total cost of ownership for immobilization with colloidal activated carbon that’s immediate in comparison to the pump and treat based remediation systems. And if we look at the financial flexibility, a complete reapplication of the colloidal activated carbon could be conducted every four to five years and still this alternative would have a lower total cost of ownership than the pump and treat based methods.

Well then, briefly I’ll still run through a sustainability assessment before going to conclusions. The sustainability assessment was done with a sustainability assessment tool called Sure by Ramboll. It’s a tool that’s been designed for landowners, consultants, contractors, basically anyone working with contaminated land remediation. The aim is support the remedial decision making process and then help site owners review any sustainability issues and convey and communicate those to other stakeholders. This is based on ISO sustainability remediation standard and it’s also compliant for example the SERF UK Sustainable Remediation Guidance. We have been using this in about a thousand projects worldwide and just a few months ago it won the ESG Innovation Award in the annual Environmental Analysts’ Awards and by the way this is free online for anyone if you want to go try it out.

So the sustainability assessment for this case was done by a round table assessment with three ramble remediation professionals and further commented by Region Assist. We had 15 indicators from both environmental economic and social domains and we did a semi-quantitative framing of those indicators on scale of one to five reflecting the best option being five and then the worst option being one and likewise we weighted all of those indicators on scale one to five describing the relative importance of those. Indicators that we used in the environmental, social, and economic domains were focusing on the greenhouse gases, water, natural resources, but on the society side we were looking more at the long-term risk management aspects, the ethics of remediation, how it impacts the built environment now and in the future, and how it then helps communicating and managing the uncertainty to the future and in the economic side we were of course finding a lot of the assessment on the life cycle cost assessment but also looking at things like the job creation, new skills generation, flexibility and so forth and if we look at the results this graph shows the total sustainability assessment score.

In this assessment the score 100 reflects an ideal remediation alternative. So it would be number five on this assessment on all of the scores and domains. And then everything zero would be then the lowest possible score. And as we can see the immobilization with colloidal activated carbon reached a total score of 83, – mainly driven by environmental and economic indicators. If we look a little bit more in detail where those differences came – so especially in the environmental domain, the immobilization with colloidal activated carbon had clear benefits due to low greenhouse gas emissions, minimal energy and material footprint. In the societal side, immobilization with GAC had clear benefits from supporting the polluter-based principle and thus minimizing also the impacts on the built environment and so forth. And on the economic side, as we went through, it had the colloidal activated carbon alternative benefits from a very low total cost of ownership.

So, conclusions from the sustainability assessment, the immobilization with colloidal-activated carbon had a 100% higher sustainability assessment score compared to the pump-and-treat-based remediation alternatives. And the most significant impact in terms of sustainability was that the colloidal-activated carbon remedial alternative superseded the pump and treat based alternatives, especially in the environmental economic sustainability and that was specifically due to the low greenhouse gas emissions, minimal energy and material footprint and then the low total cost of ownership and high financial flexibility. Then if we look at the pump and treat with whether with activated carbon or with phone fractionation. The sustainability benefits came through the reduction of residual PFAS in the subsoil and from low perceived technological uncertainty. We’re having a technology that’s been applied often and also the pump and treat. I say there’s a bit more labor intensive remediation method. It benefits the local employment more due to extensive installation and constant OM work required. So then just a few conclusions and key findings.

To sum up, based on the life cycle assessment, life cycle cost assessment and the sustainability assessment, the immobilization with colloidal activated carbon had 40 to 70 times smaller carbon footprint in CO2 equivalent emissions at 95% plus smaller raw material energy and waste footprint and 60 to 65% smaller total life cycle costs compared in net present value. And then also viewed on the more semi-quantitative multi-criteria analysis for the sustainability assessment, also including the social sites, the colloidal activated carbon had 100% higher sustainability score compared to the alternatives. And then just a few additional notes. When doing site remediation, you should always consider sustainability and that allows you to understand that the remediation is not happening in isolation. All the actions that we do to reduce contamination levels they have impact somewhere else in the society or in the environment or in the economy. So take a balanced and holistic approach for this.

In our example the environmental benefits from the colloidal activated carbon technology are immediate and for example the reductions in the climate impacts those can be achieved now that is very important looking into phase of the climate greenhouse gas emissions that are being currently generated and the climate impact that that is having. If we look at this kind of novel innovative technologies like the colloidal activated carbon is, it has also a potential for introducing significant carbon handprint for the project in comparison to other alternatives and the product itself has the opportunity of negating climate emissions through long-term carbon sequestrations back to the soil. And in every project, I want to highlight that there are some simple ways of producing the negative sustainability impacts and these are very simple tools such as using biogenic waste materials, for example for activated carbon production, reducing any off-site waste treatment and trying to increase circularity or projects, and using for example electricity from renewable sources, preferably sourced on-site.

With these words, I want to thank you very much for listening to the presentation on the sustainability impacts on this case. Thank you. All right, thank you Jarno.