WEBVTT 00:00:00.000 --> 00:00:00.000 And define a much more effective target. If our goal is to establish say a pump and treat boundary to stop that offside migration. 00:00:00.000 --> 00:00:00.000 You can see where the hotspots are and you can start to plan better. 00:00:00.000 --> 00:00:00.000 So this is what it looks like in a kind of a quasi 3D rendering. So you can see there's some migration off to the top of the page by the words Buckley. 00:00:00.000 --> 00:00:00.000 But the magnitude of the flux is a lot lower. You can see migration following these surface water features. 00:00:00.000 --> 00:00:00.000 There's preferential flow, higher permeability associated with the hydrophases. Coincident with those, surface water features. 00:00:00.000 --> 00:00:00.000 And then at the edge. Transact app now you can see if you wanted to establish a barrier by concrete or by injectable colloidal carbon. 00:00:00.000 --> 00:00:00.000 You've got it pretty much mapped out. You could refine it as needed. But it's getting you a lot closer to where you need to be. 00:00:00.000 --> 00:00:00.000 I'm gonna talk briefly on source evaluation. Understanding source strength is really the key to understand whether PFOS and a soil poses a risk to ground. 00:00:00.000 --> 00:00:00.000 There's several different methods that you might use. Really simple and effective one is looking at the ratio of the soil concentrations to the ground water concentration. 00:00:00.000 --> 00:00:00.000 It's ideal if you have a But you can start to do averaging just to get a sense of where you're at. 00:00:00.000 --> 00:00:00.000 The SPLP is the go-to, right? USEPA dilution attenuation factor has relied on SPLP. 00:00:00.000 --> 00:00:00.000 That's certainly a reasonable approach. Might be conservative because it's pretty destructive. At P. 00:00:00.000 --> 00:00:00.000 Soyo interactions are more complicated than just hydrophobic interactions. Partitioning at the air water interface. 00:00:00.000 --> 00:00:00.000 So SPLP is probably conservative. Still, it's a repeatable measurement that one can make. 00:00:00.000 --> 00:00:00.000 Then the other end of the spectrum is like symmetry and poor water sampling. So the idea is you could get a sample that's in equilibrium with those contaminated soils. 00:00:00.000 --> 00:00:00.000 See what the actual institute leeching is. Lot of data coming together to better understand how we can use that. 00:00:00.000 --> 00:00:00.000 So stay tuned. I think you'll see much more information. At the end of the day though, you wanna combine these results. 00:00:00.000 --> 00:00:00.000 To understand. What the relationship is between your site soils, your site source. And the potential to create a ground water flow. 00:00:00.000 --> 00:00:00.000 Right. So. The human health based standards for PFOS are many, many orders of magnitude higher than the soil, the groundwater protection standards, screening levels, right? 00:00:00.000 --> 00:00:00.000 So. I think we need to start to dig into this more carefully because Some of the data talk today about background concentrations and precipitation being in the hands, even hundreds of nanograms per leader. 00:00:00.000 --> 00:00:00.000 But figuring out where the background is gonna matter figuring out which part of the source really matters is the discussion and the decision for the day, I'd say. 00:00:00.000 --> 00:00:00.000 So now that switch to the final part of it, which is the flux monitoring. So I can't emphasize enough if you can't do high reside characterization everywhere. 00:00:00.000 --> 00:00:00.000 Today it really does make sense to at least do a metric property boundaries. If you've got receptors at risk. 00:00:00.000 --> 00:00:00.000 Figure out where the migration pathways are and collect the data you need. So that the image you're looking at is Ielson Air Force Base. 00:00:00.000 --> 00:00:00.000 We're doing a PFOSRI there. And this transact is 2 miles long. Probably have 300 vertical aqua for profile samples going down as deep as 200 feet. 00:00:00.000 --> 00:00:00.000 I'll show you that in a second. But, With this image, even just showing the worst case concentration, you can see. 00:00:00.000 --> 00:00:00.000 Based on the heat map, where most of the action is, where the orange and red are, that's where the majority of the, mass is moving. 00:00:00.000 --> 00:00:00.000 Now we can zoom in and figure out. What the potential for offside migration is we could take measures to cut off the majority of that mass flux and that's discharge using this the approach. 00:00:00.000 --> 00:00:00.000 And this is ultimately one of the things we're pushing. When people are thinking about, to use this approach. 00:00:00.000 --> 00:00:00.000 Don't expect you to be able to read the numbers. Hopefully you can see the color dots, right? 00:00:00.000 --> 00:00:00.000 And I've shaded the highest concentration area. So this is 2 miles long, 10,000 plus 50, right? 00:00:00.000 --> 00:00:00.000 Huge vertical exaggeration. Samples are nominally every 20 feet apart going into That's with the aqua part. 00:00:00.000 --> 00:00:00.000 So you can see there's, an area. No, nominally about 2,500 feet wide. 00:00:00.000 --> 00:00:00.000 Where we've got the highest concentrations. And the ground water. So the area that we boxed. 00:00:00.000 --> 00:00:00.000 We're actually going to do an evaluation. With injected. Hello. Test whether that technology is going to be able to reduce SMS discharge. 00:00:00.000 --> 00:00:00.000 To offsite. So we're gonna zoom in in a 500 foot segment. We're going from nominally one to 2 boring with samples every 20 feet. 00:00:00.000 --> 00:00:00.000 So now we're gonna have 8 clusters, triplets. We're gonna do continuous passive flux meters in those 50 foot screens. 00:00:00.000 --> 00:00:00.000 So the screens are set up to a depth of a hundred 60 feet. They were also going to compare these results. 00:00:00.000 --> 00:00:00.000 The slug tasks that you might get from the well and samples that you might get through the well. What's probably even more important though is the comparison we could make it to the high reset that we did that was 2 miles wide and see how representative that really is, right? 00:00:00.000 --> 00:00:00.000 So with that, I think I can take questions. 00:00:00.000 --> 00:00:00.000 Alright, without sounding too confident, I think we've resolved the audio issues here in the room. 00:00:00.000 --> 00:00:00.000 For those of you in the room, if you can't hear, I do apologize. If you're in the back, there are seats closer up front that might be the easiest solution we have for getting better volume. 00:00:00.000 --> 00:00:00.000 But if you have a question in the room, you can raise your hand. Be happy to bring a mic. 00:00:00.000 --> 00:00:00.000 And for those of you around the table, those microphones are working correctly. 00:00:00.000 --> 00:00:00.000 So working. Thanks, Joe. On the mass flux front. Yeah, really. 00:00:00.000 --> 00:00:00.000 We paid for the first past the flux meter deployment at a mic addable shop at it. 00:00:00.000 --> 00:00:00.000 If. It's on. Is it any better? Oh, okay. 00:00:00.000 --> 00:00:00.000 Anyway. You know, when Mike Animal developed the first past 6 months meter, we paid for the deployment at a Marine Corps base and it, we paid for the deployment at a Marine Corps base in the southeast. 00:00:00.000 --> 00:00:00.000 And then now the issue was cost we were working with at a landfill. Camp waste management. 00:00:00.000 --> 00:00:00.000 The only all the 30 or so. Lentels in their portfolio. They only had one. 00:00:00.000 --> 00:00:00.000 They thought they were gonna have to remediate. And they wanted to do a mass rocks. Performance and compliance analysis they had a 400 foot transact at the boundary of their property and they wanted to put in 2 fox meters. 00:00:00.000 --> 00:00:00.000 I'm sorry, that just wasn't enough. So my point is, I'm still not getting even. I'm still getting it very well. 00:00:00.000 --> 00:00:00.000 Yeah. No, anyway, how about now? Anyway, the point is nobody wants to put in as many blocks meters as is usually needed to really make a massive, a mass flux determination and the transsects that you showed both for Reece, I guess, and then the one at I. 00:00:00.000 --> 00:00:00.000 Hundreds of points. The point is, and your non Dod clients, are people willing to infect? 00:00:00.000 --> 00:00:00.000 You just a 2 plug question. Are they are your clients in the, especially in the private sector willing to install the necessary number? 00:00:00.000 --> 00:00:00.000 Of passive flux meters, for example, to be able to make an adequate determination of mass flux and mass discharge. 00:00:00.000 --> 00:00:00.000 So I apologize. You translate for a weekend. 00:00:00.000 --> 00:00:00.000 Bye. In saying is that. Because of a high cost large number of points. 00:00:00.000 --> 00:00:00.000 You may be able to get that kind of money out of the Department of Defense. Are you seeing it elsewhere? 00:00:00.000 --> 00:00:00.000 In other. Industries, other private clients, whatever. Alright, thanks. Sorry, I couldn't hear you, Jen. 00:00:00.000 --> 00:00:00.000 You know, I would say you say. The Department of Defense is far ahead of our commercial clients when it comes to be fast characterization. 00:00:00.000 --> 00:00:00.000 Most of the significant work we're doing in the commercial space I'd say is driven by litigation. 00:00:00.000 --> 00:00:00.000 And, then they followed the 2 categories. Some are. Doing the conventional circle approach. Hello, multiple faces. 00:00:00.000 --> 00:00:00.000 Others are very interested in getting the high-rise site characterization because they want to get to the answers as soon as they can. 00:00:00.000 --> 00:00:00.000 So it's still a mixed bag, but you know the technology is still not. What everybody is used to when it comes to things like Florida and solvents, for example. 00:00:00.000 --> 00:00:00.000 So I think over the course of the next year as the screening methods come into play. I think we will see a lot more people. 00:00:00.000 --> 00:00:00.000 Adopting the approach. Even though even the folks that we've been working with who are willing to try mass flux. 00:00:00.000 --> 00:00:00.000 One of their problems is they say the client has no idea what to do with the data. And the 3D visualization packages that are out there as a general matter. 00:00:00.000 --> 00:00:00.000 Don't have the modules to allow mass flux to be incorporated into their depictions. So what do you guys doing to Especially the latter problem is if you're trying to These mass trucks determinations. 00:00:00.000 --> 00:00:00.000 And decision making. Are you working? Are you developing your own modifications? The 3D packages? 00:00:00.000 --> 00:00:00.000 Are you working with EVS or leapfrog? What, are you doing or needs to be done to incorporate mass flux into the 3D packages? 00:00:00.000 --> 00:00:00.000 You hear that one. I can hear myself. 00:00:00.000 --> 00:00:00.000 Come on back here. I got all of that either, but, I think what you're asking is because many in the public don't maybe have a tool that Joe does or his people have. 00:00:00.000 --> 00:00:00.000 What, what, what, what can be done? What are we doing? What is somebody doing to try and, the general public, I guess, using, Digital CSM, 00:00:00.000 --> 00:00:00.000 . We. 00:00:00.000 --> 00:00:00.000 Okay. Oh, We are working in Okay. 00:00:00.000 --> 00:00:00.000 Okay, Hey, I mean, You know, Alright, so what I think I'm hearing again, Joe didn't catch this, but, I think I might have. 00:00:00.000 --> 00:00:00.000 You're asking, Given that the available 3D packages. Are kind of weak in their ability to incorporate mass blocks data. 00:00:00.000 --> 00:00:00.000 What are we doing to and work with the developers of those. Packages to improve that. Is that right? 00:00:00.000 --> 00:00:00.000 Okay, so thanks for the translation there, Ken. I think my hearing aid batteries just went out on me. 00:00:00.000 --> 00:00:00.000 Yeah, first, you know, I think it's a never ending battle. Talking about irres because the perception is it's high cost. 00:00:00.000 --> 00:00:00.000 Bye. And that's why I always lead with my return on investigation concept because Some aspects of high reside characterization are more expensive, but we can reduce the time frame. 00:00:00.000 --> 00:00:00.000 For example, with the Buckley P. Just with sequencing our work, I think we got the phase one RI done in 2 years, 2 field seasons. 00:00:00.000 --> 00:00:00.000 And that's much faster than a lot of the other ones are. If we start to apply real time characterization. 00:00:00.000 --> 00:00:00.000 Now we're in a situation where you could do things. Quite fast. The key question you asked him about. 00:00:00.000 --> 00:00:00.000 Fusing 3 dimensional interpretation and concentration to get at. Relative flux is really an important one. But I think There's an angle that we can approach it to make it more manageable and more effectively utilized, right? 00:00:00.000 --> 00:00:00.000 So we're probably never gonna be able to do high reside characterization to the point where we can truly characterize every aspect of a sight and Bye. 00:00:00.000 --> 00:00:00.000 That's super expensive. So we've advocated. Since we wrote remediation hydraulics 15 years ago. 00:00:00.000 --> 00:00:00.000 Is let's zoom in and classify the behavior and understand the critical importance of stratigraphy and mass transfer among the addiction slow reduction and storage zones. 00:00:00.000 --> 00:00:00.000 To develop a conceptual model. But then we can extend. To pseudo creating. Because I don't think we'll ever be able to truly do 3 dimensional characterization at these sites. 00:00:00.000 --> 00:00:00.000 But we can get the data where it matters most. And so a good starting point. I think is. 00:00:00.000 --> 00:00:00.000 You do it at the property boundaries to understand your strategy to protect receptors. If you do it at sources, so we have a good idea of what's the mass flux or mass discharge is at every source. 00:00:00.000 --> 00:00:00.000 So now we can rank and prioritize. To be more cost effective, make quicker decisions. I think that's a good first step. 00:00:00.000 --> 00:00:00.000 As we catch up on screening methods. I think there'll be opportunities to fuse this in threed. 00:00:00.000 --> 00:00:00.000 Certainly the power of computers is much different than it used to be and I think we'll get there, but I think the age-old problem is Just because we can, it doesn't mean we will. 00:00:00.000 --> 00:00:00.000 And I think we gotta balance our expectations. Hopefully that answers the question. I appreciate your patience with me not being able to hear the question. 00:00:00.000 --> 00:00:00.000 Good one all day, but let's move on. Thank you, Joe. 00:00:00.000 --> 00:00:00.000 So our next speaker is Craig. Vine, and also from Arcadis. Asked him to come and talk with us a bit about. 00:00:00.000 --> 00:00:00.000 Technologies and methods characterizing P-ass mass blocks in groundwater surface water interfaces. Craig is a technical expert, senior vice president, arcadis, 25 years of experience. 00:00:00.000 --> 00:00:00.000 So he's a little younger than Joe currently. Characterizing your meeting. PEOPLE, PEOPLE Investigator, Numerous Certificate, and Projects and. 00:00:00.000 --> 00:00:00.000 Has had its fingers all over Sentinel passive samplers and hrx well technology Bachelor's degree, we can college, master's degree, Colorado State and. 00:00:00.000 --> 00:00:00.000 Hey Steve, our school of mine. So I know 2 of those schools. Great. 00:00:00.000 --> 00:00:00.000 Right. Thank you, Ken. Thanks, everybody. Are, is there a controller? 00:00:00.000 --> 00:00:00.000 Is it? I can't see it. All right, well, thanks everybody. Again, I'll be focused specifically on kind of reviewing the status of available technologies for understanding interactions like groundwater service water interfaces particularly in the context of our And, so just an outline. 00:00:00.000 --> 00:00:00.000 I'm gonna set stage a bit just to remind us of some unique features and characteristics of PFAS that I think my, thesis is that we are gonna be doing a lot more work in GSI. 00:00:00.000 --> 00:00:00.000 Grammar, surface modern, interactions. In this P fast problem that we've done for any other, I think it's a huge, a huge issue. 00:00:00.000 --> 00:00:00.000 And then I've got just a kind of a conceptualization of one of the most common problems we're currently working on in the DOD space, are currently working on in the DOD space, of one of the most common problems we're currently working on in the DOD space, a fire training area or form of training area. 00:00:00.000 --> 00:00:00.000 One of the most common problems we're currently working on in the DOD space, a fire training area or form of training area. 00:00:00.000 --> 00:00:00.000 And just that are real real sites, real situations, real data that sort of understand highlight. This, potential problem and what I would say somewhat surprising interactions. 00:00:00.000 --> 00:00:00.000 And then I'm gonna go into just sort of a summary of some. Characterization tools and some that are developing and bows a little bit of thoughts on where I think we're headed. 00:00:00.000 --> 00:00:00.000 Okay, so I know, some of this is review, but I just again wanna set the stage again. 00:00:00.000 --> 00:00:00.000 First of all, of course, PFAS are biological, resistance about biological antibiotic degradation processes. 00:00:00.000 --> 00:00:00.000 So they're persistent. And by the way, there's a lot of references through this. 00:00:00.000 --> 00:00:00.000 There's a complete citation list and one last slides. You want the complete reference list. 00:00:00.000 --> 00:00:00.000 They absorb to sediment and microplastics. 00:00:00.000 --> 00:00:00.000 They can exhibit self-assembly behavior. Yeah, particularly higher concentrations, so complex behavior. 00:00:00.000 --> 00:00:00.000 They're known to partition into non-aqueous phase liquids. Including oil phase. 00:00:00.000 --> 00:00:00.000 They concentrate at air water interfaces. They have infinity to an air water interface. This is fact. 00:00:00.000 --> 00:00:00.000 So these are all sort of unique. You know, this isn't just a salt. This is a complex system. 00:00:00.000 --> 00:00:00.000 And so if you think about just this is the photograph I took of just, you know, some run off on a parking lot. 00:00:00.000 --> 00:00:00.000 Look at these phases that are present. Course you got the water phase you got sediment that's mobilized in a storm events. 00:00:00.000 --> 00:00:00.000 You got a And you've got bubbles. So, you know, now we've got this potential for a really unique distribution in a given, a really unique distribution in a given, water system. 00:00:00.000 --> 00:00:00.000 And of course, that also changes in time space in a given, water system. And of course, that also changes in a given, water system. 00:00:00.000 --> 00:00:00.000 And of course, that also changes in time space in surface wire conditions. The contaminant sources and release scenarios for P fast. 00:00:00.000 --> 00:00:00.000 They're unique compared to what we're dealing with them. They're not like, is solved on us. I like PCBs. 00:00:00.000 --> 00:00:00.000 I mean, we've got fire training areas and hard scapes. We've got agricultural fields that had bio solids apply to few slate we have P fast and roofing materials. 00:00:00.000 --> 00:00:00.000 There's P fast and rain and some place. So, you know, the source terms are quite a bit different, particularly as they could impact surface water features. 00:00:00.000 --> 00:00:00.000 And because of this, we're starting to see evidence of. P fast distribution that we haven't seen for chlorine and solvents for example. 00:00:00.000 --> 00:00:00.000 There are lots of sites where we see groundwater impacts that are miles even more than 10 miles long that are associated with a surface water feature. 00:00:00.000 --> 00:00:00.000 So they are hyper exchange backwards and forwards on this particularly, 25 miles downgrade in Villsworth Air Force Base. 00:00:00.000 --> 00:00:00.000 You have round water impacts associated with P fast transfer and transport service water and an interaction groundwater interfaces. 00:00:00.000 --> 00:00:00.000 Okay, so that's for the basis of why I think this problem is going to become larger. Not smaller. 00:00:00.000 --> 00:00:00.000 And I think it's different than what we've been having to deal with for decades. So here's just a again a conceptualization of a typical current problem that we're working on. 00:00:00.000 --> 00:00:00.000 A lot of our eyes are focused around releases associated with former fire train areas, department installations. 00:00:00.000 --> 00:00:00.000 So of course you've got this former fire training area and you have, impacted hard scapes. 00:00:00.000 --> 00:00:00.000 You've got the potential for that continuous leaching off of that hardscape. In fact, I think the first presenter presented the stated before on the upper right. 00:00:00.000 --> 00:00:00.000 Sort of shows that this concrete can continuously act as a back of a continuous secondary source and that there's a first flush sort of characteristic those different curves are different runoff events. 00:00:00.000 --> 00:00:00.000 Of course you've got, you know, impact, through, through the soil zone and leakage through retention ponds. 00:00:00.000 --> 00:00:00.000 This is on automatic timer guys. And then of course, ultimately groundwater discharge and then subsequent, hybrid exchange in, in the, between the surface water and the, and the ground. 00:00:00.000 --> 00:00:00.000 Okay, now I'm gonna go through a few vignettes. 00:00:00.000 --> 00:00:00.000 This is a DOD installation in the northeast. There are high concentrations of P fast in ground water from an upgraded fire trainer where there was leaching of soil into the shallow ground water. 00:00:00.000 --> 00:00:00.000 This groundwater elevation varies through the year and at high stand it interfaces a terracotta grain below a basement. 00:00:00.000 --> 00:00:00.000 Lot of groundwater enters that chair caught a drain, runs out, expresses itself on surface. 00:00:00.000 --> 00:00:00.000 Is present in a local ephemeral pond or wetland area. There's a drain through a local berm. 00:00:00.000 --> 00:00:00.000 Kind of that retention drain and then it daylights at a storm water outfall that goes off site. 00:00:00.000 --> 00:00:00.000 So again, you know, not something that we're normally thinking about. This vignette too is actually Alsworth Air Force Base and I'll be referring this a couple of times in the presentation. 00:00:00.000 --> 00:00:00.000 There's a perennial stream that small stream that goes by the installation. And there's a fire train area for our fire trainer. 00:00:00.000 --> 00:00:00.000 Now down near the, back end of the installation. Upgraded this installation from other side activities. 00:00:00.000 --> 00:00:00.000 There's a background P fast load of page of 10,000, parts, but, into this former fire training area. 00:00:00.000 --> 00:00:00.000 There's infiltration direct from precipitation into the soil and that expresses itself as groundwater discharge to the stream and also there's some small little seeps. 00:00:00.000 --> 00:00:00.000 There have been investigations right in this zone. More water concentrations are very high and I'll show you some tools for characterizing that so we know that that loading is quite notable. 00:00:00.000 --> 00:00:00.000 And downgrade in concentrations or down screen concentrations are 4 times the upstream. 00:00:00.000 --> 00:00:00.000 And just as a comment based on some investigation, we did a demonstration of a technology that basically lines this stream with a reactive core mat, a map that has some sort absorbent and added into it. 00:00:00.000 --> 00:00:00.000 Sort of protect that up, groundwater or protect that surface water from us well and groundwater. 00:00:00.000 --> 00:00:00.000 So sort of like a reactive barrier. And that basically contained roughly, a hundred percent of the mouse and basically have, you know, downgraded concentrations roughly equal to the upgraded concentration. 00:00:00.000 --> 00:00:00.000 I won't spend much time on the technologies. For in this talk, but just to highlight how How somebody's characterization technologies then allow this focus, remedy and, receptor protection activity. 00:00:00.000 --> 00:00:00.000 The net number 3, there's a former, do the installation HAF used and firetrained extensively 00:00:00.000 --> 00:00:00.000 Run off and local springs from both the installation and there's also a wastewater treatment plant input into surface water, discharging into a medium sized leg 3 to 700 parts per trillion. 00:00:00.000 --> 00:00:00.000 Brown water in this site of the installation that or the side of the lake that discharges it. into the lake is roughly 200 parts per trillion. 00:00:00.000 --> 00:00:00.000 That results in a typical lake concentration in the tens to hundreds of parts per trillions. So this sort of this diffuse. 00:00:00.000 --> 00:00:00.000 Impact across the entire lake. But interestingly, there's a persistent way that's present on this lake. 00:00:00.000 --> 00:00:00.000 And it creates foaming on the downwind side of the lake consistently and that foam often blows up onto land and that phone of course has a high concentration. 00:00:00.000 --> 00:00:00.000 And then subsequent precipitation infiltration is impact of groundwater on the other side of the lake. 00:00:00.000 --> 00:00:00.000 And is now present in domestic wells in the tens and parts of their children. So again, you see kind of boundary crossing largely driven by some of the unique features of this. 00:00:00.000 --> 00:00:00.000 Then yet 4. This is in Southern California. There's a. Background load into a regional river from manufacturing and industrial use mostly a lot of industrial discharge into the service slaughter. 00:00:00.000 --> 00:00:00.000 And for years, the water provider as. Diverted some of that flow. Sort of, for storage and recovery. 00:00:00.000 --> 00:00:00.000 Operation. Or set has impacted ground water and now we have high capacity production wells that have a very large service area that are in the tens of And then finally the fifth thing yet. 00:00:00.000 --> 00:00:00.000 This is in, southwest Missouri. It's a regional airport that intentionally manages its storm water by diverting it into swallow holes in a car setting. 00:00:00.000 --> 00:00:00.000 So very convenient way and fast way to get rid of a lot of water. But of course, very rapid introduction. 00:00:00.000 --> 00:00:00.000 Into a car setting as well as you know much about cars of course transport is very fast and also springs access or focal points. 00:00:00.000 --> 00:00:00.000 For groundwater discharge in those settings. So, springs nearby, they're fiber, somewhere 5 or 8 springs that are likely sourced in this area. 00:00:00.000 --> 00:00:00.000 They all show tens of parts per trillion of It's also heavy agricultural, biosol application, manufacturing. 00:00:00.000 --> 00:00:00.000 So there's also impacts to various domestic wells. Specific pathways to those are a little bit clear. 00:00:00.000 --> 00:00:00.000 But we see a domestic. Well in this car system 00:00:00.000 --> 00:00:00.000 So again, just sort of stage setting, I think. That's the basis for. Thinking that we need to spend more energy on this problem. 00:00:00.000 --> 00:00:00.000 So in terms of the toolbox for characterizing groundwater, interactions. There's a whole bunch, some of them old, some of you are familiar with, some of them new. 00:00:00.000 --> 00:00:00.000 The orange ones are a little older and I won't really go into those. And the blue ones I'll spend a little bit more time talking about. 00:00:00.000 --> 00:00:00.000 But of course you have, you know, paisometers for hydraulic characterization and data loggers and allows conventional tools are still very relevant. 00:00:00.000 --> 00:00:00.000 Push points and poor water samplers, Henry samplers, those sort of things are still very relevant for certain use cases. 00:00:00.000 --> 00:00:00.000 Seepage meters been around decades still very relevant. But don't meet all of the needs. 00:00:00.000 --> 00:00:00.000 Particularly for more complex settings or really understanding mass flux or looking at different space and time measurement either volumes or time intervals. 00:00:00.000 --> 00:00:00.000 And sometimes that's, as important as anything. Do you, are you interested in something discrete in time or space or you care more about a time weighted average or something that's more about a time-weighted average or something that's more about a time-related average or something that's more volume average, maybe need to understand So I'll be talking about passive samplers as we've been discussion on that before and 00:00:00.000 --> 00:00:00.000 I'll. I'll spend a little bit more time on some options. They're developing currently. 00:00:00.000 --> 00:00:00.000 Stream bed, passive flux meter. So Jim message and pass the flux meters. They didn't adapt it. 00:00:00.000 --> 00:00:00.000 And look at, vertical flow and, subscription. Point velocity probes that have been adapted for surface water grammar interactions something called and then some tracer testing and also touch on. 00:00:00.000 --> 00:00:00.000 So I'm gonna there's a number of different passive samplers that are that are under development some are commercially available and then, I think maybe 3 years ago, sort of had a state and a need, and they funded roughly a dozen projects and actually have a sum of those products is sort of a supplemental slide deck. 00:00:00.000 --> 00:00:00.000 This particular sampler was developed through that program. As you can see in the photograph and the kind of upper right that orange box. 00:00:00.000 --> 00:00:00.000 It's a small luggage tag sampler. With a small,sorbent media in that circle and this, this, has developed in partnership between our Kais and Booster College. 00:00:00.000 --> 00:00:00.000 We selected this particular Zorbid. It's an organic silica. Oh, Osorb, if you're interested, but because it's got a very fast, uptake rate. 00:00:00.000 --> 00:00:00.000 And it has a very high capacity and also that uptake rate capacity is relatively sensitive. Geochemical conditions. 00:00:00.000 --> 00:00:00.000 It's not very sensitive to pH, So the idea behind this kind of a sampler is you deploy for a period of time. 00:00:00.000 --> 00:00:00.000 Almost like fly paper in the barn, it'll pick up flies as flies come by and then after a period of time you count the flies on the fly paper and you know the time that that fly paper was deployed and you have a time weighted average. 00:00:00.000 --> 00:00:00.000 Or set you know that requires accuracy on your pickup rate or that sampling rate. But I would say, you know, there, that's the one of the key advantages that you get a time weighted average concentration which may be important in some settings particularly if you are more interested in sort of chronic loading or average loading as opposed to some sort of peak condition or if you didn't know if 00:00:00.000 --> 00:00:00.000 there was. A high degree of variability. One of the data sets on the right, this was demonstrated at Elsworth Air Force Base, the in that small surface water feature. 00:00:00.000 --> 00:00:00.000 And one of the things we noted, we collected samples twice a day, grab samples twice a day for a week of the same deployment period of this passive sampler and concentrations varied daily by 50%. 00:00:00.000 --> 00:00:00.000 At a given location because flow was highly variable actually driven by freeric activity of flow very roughly 50% in the late afternoon flows were really down. 00:00:00.000 --> 00:00:00.000 That's the uptaking all that water and the flows picked up. In the middle of the night so anyways the point is it's a highly dynamic hydraulic system and So in this application, I'll pass a sampler is the, this kind of passes. 00:00:00.000 --> 00:00:00.000 For example, digit time weighted average. Can also be used in groundwater applications and data set on the right, all that those 2 data sets are comparison between the passive sampler. 00:00:00.000 --> 00:00:00.000 Answer or the passive sampler value on the y-axis and the conventional method answer on the X-axis. 00:00:00.000 --> 00:00:00.000 Those are both log log scale so you can see really good, some linear performance order. 5, 6 orders of magnitude. 00:00:00.000 --> 00:00:00.000 These particular samplers are available, commercially. And when we design these, we design these to be really compatible with current laboratory. 00:00:00.000 --> 00:00:00.000 Methods so basically in the sense this is actually a solid-faced extraction step in the labs when they're in the field so when they're getting lab they simply do an ethan so it's compatible with 63 and 5 37 1. 00:00:00.000 --> 00:00:00.000 So that's that those applications are specifically for either open surface water or brown water but they of course also can be buried in a sediment application. 00:00:00.000 --> 00:00:00.000 We're sort of modifying the prototype to make a little more robust. Feel it burying sediment. 00:00:00.000 --> 00:00:00.000 Those are the 2 images on the left. There's also a couple of available commercial. Options as well. 00:00:00.000 --> 00:00:00.000 The tellhouse one, as does the serum as this passes sample or the The Batel sampler is an integrated sampler like the one I've been talking about. 00:00:00.000 --> 00:00:00.000 So it gives you a time weighted average. The other sample on the right, be fastive is a is an equilibrium sale. 00:00:00.000 --> 00:00:00.000 So again, what's not necessarily better than the other sort of hence what you're looking for. 00:00:00.000 --> 00:00:00.000 In terms of the types of day-to-day that call objectives. 00:00:00.000 --> 00:00:00.000 Stream bed passive flux meters for those of you are not. Familiar with a passive flux meter. 00:00:00.000 --> 00:00:00.000 As Jim mentioned, this was developed by Mike Annabel, the University of Florida, probably 20 years ago now, I guess, maybe longer. 00:00:00.000 --> 00:00:00.000 And the idea is, you deploy a granular activated carbon that's been impregnated with a suite of tracers that have a known illusion rate. 00:00:00.000 --> 00:00:00.000 And you deploy that conventionally it would be in a monitoring well. And as groundwater flows by through that carbon, it eludes tracers. 00:00:00.000 --> 00:00:00.000 And that, a trace or illusion is proportional how much. Water flux has occurred so you can then on the backside look at your trace or mass loss and deduce how much flow there had been. 00:00:00.000 --> 00:00:00.000 Coincidentally, at the same time, you also are absorbing contaminants. So now you have both how much water is moving and how much contaminant mash. 00:00:00.000 --> 00:00:00.000 Absorbed over that time period so that gives you a mass flux value And again, conventionally they were, originally they were designed to be fit into monitoring well. 00:00:00.000 --> 00:00:00.000 So they measured horizontal flux through modern well, but they've been adapted to look at vertical flux through a stream bet. 00:00:00.000 --> 00:00:00.000 So in this case, you would drive this or install it into a strain bed. And then as groundwater enters the lower, lower screen, you can see there's an upper and lower screen, and there's a lower screen, passes through that carbon and discharges to the upper screen. 00:00:00.000 --> 00:00:00.000 You have the same sort of flow configuration and the same similar sort of calculations. 00:00:00.000 --> 00:00:00.000 This data set on the right again was from that vignette to Ellsworth Air Force Base where he combined a lot of these different methods. 00:00:00.000 --> 00:00:00.000 On the left is, left accesses concentration, from, from, both surface water samples and also poor water samples. 00:00:00.000 --> 00:00:00.000 So those are the blue and orange series. And then the greenish bars are the passive. The stream that pass the flux meters that were installed those different points along the street that so I'm not gonna go in at length into what these data mean specifically just to show how these data tools were used in concert and then ultimately this is the siphon. 00:00:00.000 --> 00:00:00.000 We didn't develop the demonstration for winning those wreck formats. On, on the surface, or a stream bed service to protect, for ground what, from groundwater discharge into the search slaughter feature. 00:00:00.000 --> 00:00:00.000 Next technology is a stream bed point velocity probe or SPVP. And sort of like passive flux meters, the PVPs were developed maybe 15 years ago or so by Rick Devlin and his colleagues. 00:00:00.000 --> 00:00:00.000 This was originally designed to go in a well and to measure velocity, groundwater velocity in the well. 00:00:00.000 --> 00:00:00.000 And it essentially is a local tracer test method. It's been adapted and you can see on the image on the left to match a vertical flow configuration and you can see there's an injection port. 00:00:00.000 --> 00:00:00.000 And then detectors above and below that injection port. So the way this works is a very small. 00:00:00.000 --> 00:00:00.000 Volume of trace or salt base trace or either, you know, a table salt or actually could be distilled water, something that creates a specific connectivity contrast is injected through that port. 00:00:00.000 --> 00:00:00.000 At a known time and known volume. And then the arrival of that that tracer solution is detected above or below by those detectors. 00:00:00.000 --> 00:00:00.000 So that distance is known and the volume is known and basically you fit that breakthrough curve to get a local velocity. 00:00:00.000 --> 00:00:00.000 So this is a data set that Rick gave me where they did an intensive sort of investigation. Across a stream channel and you can see all the points where they deployed this, point velocity pro, but has the advantage that you can deploy it? 00:00:00.000 --> 00:00:00.000 Pick it up, deploy it again, pick it up, deploy it again. So it's, reusable and it gives you, you know, in terms of that measurement scale, it gives you very local measurement scale of both, of a spatial measure of velocity, but also temporal. These tests are typically an hour too long. 00:00:00.000 --> 00:00:00.000 So they. They represent sort of a snapshot and time a passive flux meter I mentioned in the slide before typically deployment time might be one to 3 weeks. 00:00:00.000 --> 00:00:00.000 So a little bit longer time weighted average, but still spatially a local measurement. And of course this velocity data can be paired with. 00:00:00.000 --> 00:00:00.000 Pour water concentration data to get you mass flux information down with us. And those are the color flood graphs on, right? 00:00:00.000 --> 00:00:00.000 This one I wanted to mention is still sort of in development, but it's pretty cool developed by folks. 00:00:00.000 --> 00:00:00.000 At Pacific Northwest National Lab. It's a thermal electric water flux detection pro. 00:00:00.000 --> 00:00:00.000 Basically it's a probe that has pressure temperature, fluid connectivity, bulk electric and bulk electrical contact to get sensors all along the axis. 00:00:00.000 --> 00:00:00.000 Any ideas that you drive this into, a sediment in a surface water interaction setting. And high resolution time data series are collected on connectivity and head primarily temperature as well. 00:00:00.000 --> 00:00:00.000 And that data can give information about, permeability. Perosity and of course ultimately then groundwater velocity or flux and direction. 00:00:00.000 --> 00:00:00.000 And so the, I would say the advantage of this compared to somebody else is. Really high time, time resolution. 00:00:00.000 --> 00:00:00.000 So very good in highly dynamic settings like you know, could be title settings. In this case, I think they were using them sick nor request. 00:00:00.000 --> 00:00:00.000 Where a lot of the hydroelectric dams have very variable stage operation in it creates gradient reversals, multiple times a day or maybe more frequent. 00:00:00.000 --> 00:00:00.000 So that was sort of the needed that was driven there. If you're interested in that, I encourage you to contact and Johnson. 00:00:00.000 --> 00:00:00.000 Now we're going up a little larger in scale. This is a technique we also use that been yet to, elsewhere, the Air Force Base is a stream dilution tracer test. 00:00:00.000 --> 00:00:00.000 And the idea here is you're now trying to get more of a spatial average or spatially represented value of flux. 00:00:00.000 --> 00:00:00.000 Those measurements I gave you or those tools I gave you give you really local scale measurements which are valuable but to have any sort of representation. 00:00:00.000 --> 00:00:00.000 You know, you need a pretty high number of them to account for heterogeneity and variability. 00:00:00.000 --> 00:00:00.000 This method gives you more of a reach average value. In this case, you apply. A known steady concentration of tracer. 00:00:00.000 --> 00:00:00.000 To a surface water feature at the upgrading end. And you do this continuously. So, you know, maybe you're pumping it in. 00:00:00.000 --> 00:00:00.000 Let's say the stream is running at. You know, a tenth of a CFS and you Make a little more and you pump in, tracer at maybe 10% of that or 5% of that and you mix that tracer so that tracer now has at that injection point a steady concentration. 00:00:00.000 --> 00:00:00.000 And then as you measure. Tracer in stream down gradient If there is groundwater discharge into that stream, you will see a dilution signal. 00:00:00.000 --> 00:00:00.000 And so the amount of dilution you see downstream Really just a mass balance calculation can be used then to calculate how much groundwater has been upwelling between that point in your previous measurement. 00:00:00.000 --> 00:00:00.000 So here's an example. Data said this is from, Ellsworth. The orange circle series or red circle series are the in-stream tracer concentration so you can see a steady decline and normalized tracer concentration. 00:00:00.000 --> 00:00:00.000 Where we are putting it in, it's a hundred percent and at the very end of the reach that we were measuring it was roughly 50%. 00:00:00.000 --> 00:00:00.000 Of the starting concentration. And so then those 2 other series, the black series are. Segment by segment calculations of groundwater discharge for that segment and the, yellow is this accumulation of that. 00:00:00.000 --> 00:00:00.000 I think less applicable but sort of interesting. You can also do an in well. Tracer test if you've got a losing reach and you're interested to understand where that water if it's P fast impact it could go. 00:00:00.000 --> 00:00:00.000 So this example I'm going to show you is a real field case. It wasn't used in the context of P fast and it certainly could be. 00:00:00.000 --> 00:00:00.000 In this case, a dissolved gas tracer. In this case, we use silver hexafluoride that there's other options. 00:00:00.000 --> 00:00:00.000 Was continuously applied to a stream reach. We use diffusion stones and this chief steady state conditions. 00:00:00.000 --> 00:00:00.000 Brand this test for roughly 3 months. So that's one of the advantages. That's all gas tracer. 00:00:00.000 --> 00:00:00.000 You can just simply switch out tanks and the logistics are pretty easy. Also with this particular trace, there's a really high sensitivity. 00:00:00.000 --> 00:00:00.000 A range of detectability with the tracer. And then we had a pumping well nearby. 00:00:00.000 --> 00:00:00.000 So we knew this was a losing reach, but we were interested in how much of that pumping well, the water came out of pumping well. 00:00:00.000 --> 00:00:00.000 Was creek water and we're also interested in transport time and also just in general how so what was that capture envelope how much the stream was being pulled so you can see the stream reach where tracer was applied that boring one see is the extraction well and we had a variety of monitoring wells. 00:00:00.000 --> 00:00:00.000 Fraser was detected and all the monitoring wells, and based on the arrival at the production bore actually took 5 days for, Tracer derive this production board as a fraction fractured sandstone so. 00:00:00.000 --> 00:00:00.000 Very high, transport in the fracture zones. You can see the tracer arrival graph on the bottom right. 00:00:00.000 --> 00:00:00.000 A pretty high concentrations and based on the relative amount of tracer in that boring we calculated roughly 5% of that boring was being sourced. 00:00:00.000 --> 00:00:00.000 From water from that Greek in this case we were a little bit more concerned about stream depletion was sort of the problem we were solving, not a container transport problem, but this would be an appropriate. 00:00:00.000 --> 00:00:00.000 Technique to adapt to understand potential impacts from losing reaches. 00:00:00.000 --> 00:00:00.000 And final, technology I wanted to highlight, is something called vertebrae segmented horizontal wells. 00:00:00.000 --> 00:00:00.000 And this is an ESTCB project. We're demonstrating that actually pairs with the work that Joe's been doing on high resolution mass flux characterization for plumes. 00:00:00.000 --> 00:00:00.000 But also has a click ability to, groundwater surface water interactions that I wanted to note. 00:00:00.000 --> 00:00:00.000 So just as a way of introduction, if you're not familiar with the vertebrae well, basically it's a Multi-screen, multi-port horizontal or well that's horizontal. 00:00:00.000 --> 00:00:00.000 So you can install this well with multiple separately plumbed screen zones that are separated by grout seals. 00:00:00.000 --> 00:00:00.000 And of course like, you know, other horizontal wells, you've got the ability to access underactive infrastructure, places that are difficult to get to, for example, underneath surface water features. 00:00:00.000 --> 00:00:00.000 It's this technology is owned by a company called Enrich. And, interestingly enough, this technology has been around for maybe 15 years and over 200 wells of these have been installed, but it's been really locally applied in Florida and in retail basically UST type applications. 00:00:00.000 --> 00:00:00.000 And the rest of the industry has been sort of unaware of this so we said hey you could take this technology and actually orient it in a transect approach. 00:00:00.000 --> 00:00:00.000 Parrot with high resolution site characterization so that you develop permanent monitoring infrastructure that was unapologetically flux focus. 00:00:00.000 --> 00:00:00.000 So that's where the focus of the ESTCP project and you could certainly do that in the context of groundwater surface water interaction, apply, install these, let's say orthogonal to a receptor or discharge point and then a surface water feature. 00:00:00.000 --> 00:00:00.000 And you could also use the conventional monitoring sense to get underneath, streams or lakes or other, other, features of interest. 00:00:00.000 --> 00:00:00.000 If you've never done any directionally drilling, it's come a long way, in the last few years, this particular system, one of the advantages of it is it uses a really small diameter boring so you can use small rigs. 00:00:00.000 --> 00:00:00.000 Let's picture the rig there on the left. In fact, a lot of these can be rented locally or sort of ditch waste or utility, so that helps reduce the mobilization costs. 00:00:00.000 --> 00:00:00.000 So photograph B is the drill bit. It's sometimes called a duck bill bid or it's an asymmetric bit. 00:00:00.000 --> 00:00:00.000 And so it goes straight that gets spins. And then when they want to turn, they stop the spinning and they push and that creates differential friction and bends the ros. 00:00:00.000 --> 00:00:00.000 And they have an unbelievably high degree of control. That was part of the performance object is part of the CSC project is really how much control do we have? 00:00:00.000 --> 00:00:00.000 Do we know where can we get the boring exactly where we want to put it and how do we know where it went. 00:00:00.000 --> 00:00:00.000 So we have a number of sort of tools looking at that and I'll just say I've been extremely impressed by the degree of control and accuracy. 00:00:00.000 --> 00:00:00.000 We're finding roughly your 8 your ability to hit your targets is plus or minus a foot and a half. 00:00:00.000 --> 00:00:00.000 In those geologic settings. So really good accuracy. Photographs he just shows the real time navigation system. 00:00:00.000 --> 00:00:00.000 So the driller knows real time where that bid is, there's transponder in the bid and there's a walkover system in the driller almost like a computer game can operate, and control, control the bore. 00:00:00.000 --> 00:00:00.000 Photograph, do you just, you know, I like this photograph because it's just compelling. 00:00:00.000 --> 00:00:00.000 Those 2 stakes we're putting 2 wells in and those are the planned exit stakes that are 450 feet away from the drill rate and you can see we you know they tagged that exit steak and it's knocked over. 00:00:00.000 --> 00:00:00.000 So incredibly high degree of, precision. These particular systems are interesting also and that the well is prefabricated. 00:00:00.000 --> 00:00:00.000 And brought on site on a school. So you get no geologic information during drilling. 00:00:00.000 --> 00:00:00.000 You really have no ability to modify your well. So you need a really good characterization of front to know where you want to target. 00:00:00.000 --> 00:00:00.000 And then of course when you do the install, you can see they've Daisy chained up the bit to the spool and they're just gonna slip that sheath in and then that black sheath gets removed and it's basically natural formation collapse on the screen. 00:00:00.000 --> 00:00:00.000 From the time that they daisy changed, it started pulling as well. 450 feet long to the time they were at the other end it was less than a half hour so really fast slick installation. 00:00:00.000 --> 00:00:00.000 So as I mentioned, we're currently using this in the context of. Mass discharge transsects in a plume. 00:00:00.000 --> 00:00:00.000 So this is the, the Grayling site that Joe talked about. We took his data augmented a little bit, design, transsect system shallow and deep. 00:00:00.000 --> 00:00:00.000 In this case, we're downgrading of a source area and we're gonna use this. 00:00:00.000 --> 00:00:00.000 In the future to understand the benefits of source remedy and how that changes the strength of the blue coming off the source but of course this sort of transact approach. 00:00:00.000 --> 00:00:00.000 Could be applied, you know, in the context of, upgrading of a service slaughter feature. 00:00:00.000 --> 00:00:00.000 So just some points commercially available, really cost effective. In fact, the cost per screen. Is cheaper than conventional vertical wells once you get to about 6 screens. 00:00:00.000 --> 00:00:00.000 So, very, very cost effective. There's a number of techniques that we've developed or modified to. 00:00:00.000 --> 00:00:00.000 Measure water mass. Flux across the screens including a dilution tracer testing and the use of fiber optic distributed temperature sensing. 00:00:00.000 --> 00:00:00.000 And we're, finding a good correlation between the mass discharge calculations that we're getting from this monitor, this permit monitoring infrastructure. 00:00:00.000 --> 00:00:00.000 And the pre-designed data from the high resolution site conversation. 00:00:00.000 --> 00:00:00.000 All right, just closing with what I see is some future needs and priorities. I think the storm water issue is, probably the biggest unknown. 00:00:00.000 --> 00:00:00.000 Maybe it's the largest known unknown that we have in terms of PFOS transport. I think we know there's a lot transported or likely transported as storm water and we don't have good my view good conceptual models for what happens with P and storm water and we don't have good monitoring. 00:00:00.000 --> 00:00:00.000 Tools and systems. And then of course as that relates to groundwater, you know, during storm water bench, you often have high stage and this hyper exchange. 00:00:00.000 --> 00:00:00.000 We don't really understand the nature of that and how significant that is or when does that become significant. 00:00:00.000 --> 00:00:00.000 So I think more work needs to be done there. And then as I highlighted personally, I think that settings in particular, a bit of a blind spot to us, particularly when you think about storm water impacts, you know, cars represents maybe 20% of the the US. 00:00:00.000 --> 00:00:00.000 In terms of the near surface geology. Lots of syncrolls loading potential, high heterogeneity and isotropy. 00:00:00.000 --> 00:00:00.000 Potential for really long distance transport. Springs represents sort of these focal points and integrators. So they're, really high value exposure points. 00:00:00.000 --> 00:00:00.000 Lots of complexity. I just had some photographs. You know, you have natural filming in this turbulent, sort of setting, even if you don't have to damage. 00:00:00.000 --> 00:00:00.000 You have, you know, dynamic complex flow settings. This is some photographs near my house, the picture on the right. 00:00:00.000 --> 00:00:00.000 Is a, a spring that only shows up during really high rain events, you know, so think about how you develop a conceptual model and monitoring for those kind of systems. 00:00:00.000 --> 00:00:00.000 And also, you know, exposure and mass transport. 00:00:00.000 --> 00:00:00.000 Okay, and as I mentioned, I do have some slide or some tables here that summarize some of these technologies from the commercially available samplers and then all of the sort of BSTCP passes samples around the development. And some of these have different focuses, and different purposes. 00:00:00.000 --> 00:00:00.000 And some of these have different focuses, and different purposes. So if you're interested, I encourage you to. 00:00:00.000 --> 00:00:00.000 Look at this on your own time. With that, I'm happy to take some questions. 00:00:00.000 --> 00:00:00.000 I have an online question. Alright, can you hear me okay? One of the online attendees has asked is the Sentinel certified yet? 00:00:00.000 --> 00:00:00.000 I, I don't know what's meant by certified, but, it, has had. 00:00:00.000 --> 00:00:00.000 Field demonstration. I think roughly we have about 200 field samples and that, data has been published in some scientific, refereed scientific journals. 00:00:00.000 --> 00:00:00.000 It's also part of our, sort of final report. Which we made public soon. There are several commercial labs that can analyze the sampler and they report the results as a modified 5 37 one or 1633. 00:00:00.000 --> 00:00:00.000 So, you know, I think the regulatory acceptance is sort of a case by case situation depending on the needs of the sampling program. 00:00:00.000 --> 00:00:00.000 The regulatory framework. It's central. 00:00:00.000 --> 00:00:00.000 We have another online question, but I see one in the room. Go ahead. 00:00:00.000 --> 00:00:00.000 I was just gonna ask if. How much your selection of your, I guess your monitoring technology is driven by the composition of your. 00:00:00.000 --> 00:00:00.000 Of your contaminates you know is that I mean you think about the you know like equilibrium base sampler versus, Sorben. 00:00:00.000 --> 00:00:00.000 I mean, I'm just thinking in terms of, you know, you know, the lighter, the lighter, smaller change, P fast maybe being more challenging or a equilibrium, I guess, an equilibrium based sampler. 00:00:00.000 --> 00:00:00.000 This is a sort of it. Do you, are your decisions more driven by the you're sort of and evaluation of risk or more driven by your source your contamination or as it may imagine maybe it's a mix of those things. 00:00:00.000 --> 00:00:00.000 Yeah, good question. You know, 4 fire training areas with atrip left type sources. So. 00:00:00.000 --> 00:00:00.000 The P fast suite profile is somewhat uniform and the regulatory drivers are the interests are. You know, this 4, 6, that we typically think about. 00:00:00.000 --> 00:00:00.000 I will say that, you know, all of the startup and ESTCP samplers are being evaluated against the 1633 suite. 00:00:00.000 --> 00:00:00.000 In terms of their performance and that includes the sentinel sampler and part of the reason we We use, we pick the meeting we did is that it was, had both high fast pickup or, relatively fast sampling rates for all those species and relatively high capacity. 00:00:00.000 --> 00:00:00.000 So that particular sample behaves integrated for all of them, including the short chains up till about 30 days or so. 00:00:00.000 --> 00:00:00.000 And then if you go longer, then you start to approach equilibrium for some of the shorter chains. 00:00:00.000 --> 00:00:00.000 So yeah. I think I answered your question, kind of went off, track a little bit there, but we have another question here in the room. 00:00:00.000 --> 00:00:00.000 Yes, my question is regarding the. The flow. And they monitoring data based on as you showed on the slides or the deep well shadow well and the spring And for the depo and shadow, you showed that Saba 3 to 4 milligrams per liter. 00:00:00.000 --> 00:00:00.000 In the spring, it is more very very unusual for to 62 milligrams per later. And the question what's the reason for this large answerity and determination And seems to me the flow in the spring, it is more impacted by kind of way to discharge or flow. 00:00:00.000 --> 00:00:00.000 And you used the, if 6. Or as a tracer. Now we said 6 is not as impacted by turbulent flow. 00:00:00.000 --> 00:00:00.000 As you know a PA has the the compounds we are looking into that. So how do you compare the transport? 00:00:00.000 --> 00:00:00.000 Where it is for the PFPS sixes and PS is dependent on turbulent flow. 00:00:00.000 --> 00:00:00.000 Whereas using the tracer, which is not that, and how do you explain the high concentrations and the uncertainties in the spring. 00:00:00.000 --> 00:00:00.000 I think I got most of it and I think there might be, you may be talking about 2 different. 00:00:00.000 --> 00:00:00.000 Case studies or 2 different field settings. One of the vignettes I presented had P fast impacts in a spring and also in shallow deep domestic wells. 00:00:00.000 --> 00:00:00.000 And the point there, is that, those springs certainly were impacted and we know for a fact that a PFAS likely P fast source is directly discharging their storm water. 00:00:00.000 --> 00:00:00.000 Into sync holes basically. I mean they have infrastructure around that so they're you know there's a lot of flow that goes right into that so that likely is an important contributor to the spring. 00:00:00.000 --> 00:00:00.000 There's also other PFAS sources in that watershed and there are domestic wells that are impacted in that watershed. 00:00:00.000 --> 00:00:00.000 The source of those impacts. It's unclear. It could be several. It could be, and maybe the main point of that slide is to highlight is complex. 00:00:00.000 --> 00:00:00.000 The second question you had was, or maybe the second side I think you might be referring to is the the dissolve gas tracer test. 00:00:00.000 --> 00:00:00.000 In the surface water. In that case, we used a tracer called sulfur hexafluoride. 00:00:00.000 --> 00:00:00.000 Hi, it's basically an inert almost noble gas like, company to use helium or something else. 00:00:00.000 --> 00:00:00.000 In that case, you're just looking at the dissolved concentration and we don't have We don't believe we have turbulent flow in groundwater. 00:00:00.000 --> 00:00:00.000 That is affecting The results in the sense that we still have high concentrations of that tracer arrive at the production board. 00:00:00.000 --> 00:00:00.000 So roughly 5% of what sort of the average concentration and stream was arriving at that production board. So at the very least, 5% of that borehole or that water coming out at borehole is coming from the strain. 00:00:00.000 --> 00:00:00.000 If you had some tracer de-gas in or lost maybe your bias low maybe it's actually higher than 5%. 00:00:00.000 --> 00:00:00.000 So that's possible if there was if there was some fossilization. In the consideration of all the uncertainties and the goals that's considered relatively small risk. 00:00:00.000 --> 00:00:00.000 Did I answer the question? Was I right? Is kind of 2 parts. Yes, somehow, but I think maybe there's more discussion. 00:00:00.000 --> 00:00:00.000 There's no time to discuss this. Thank you. 00:00:00.000 --> 00:00:00.000 Thank you. 00:00:00.000 --> 00:00:00.000 Well. 00:00:00.000 --> 00:00:00.000 One more presentation. Before lunch. Kind of. 00:00:00.000 --> 00:00:02.000 2 parts, 2 people, all right? This time. Anyways. 00:00:02.000 --> 00:00:14.000 Metro Viro, is the chemist with the EPA office of research and development groundwater characterization remediation division is work focuses on. 00:00:14.000 --> 00:00:27.000 Stable isotope analysis, ratio analysis. Metal speciation, it's worked as an analytical chemist prior to EPA. 00:00:27.000 --> 00:00:38.000 Gallachin and he's going to speak about applications of modified impact to groundwater tools for Yeah. 00:00:38.000 --> 00:00:44.000 I feel really lucky because I feel like a lot of the earlier presentations set me up really nicely. 00:00:44.000 --> 00:00:56.000 So. A bit of background. So. We received kind of a request that regional staff needed a method for estimating or predicting PFF migration. 00:00:56.000 --> 00:01:04.000 Through the unsaturated zone inch ground water. Ideally without having to do extensive site characterization. 00:01:04.000 --> 00:01:14.000 And initially it looks like. The kind of standard soil water partition equations of a friendly equation. Maybe suitable for P fast. 00:01:14.000 --> 00:01:15.000 But there's no consensus about the partition coefficients, the KD or the KOC values to use. 00:01:15.000 --> 00:01:29.000 You can see in this graphic, this is the distribution of reported log KD value from literature. 00:01:29.000 --> 00:01:39.000 And essentially our conclusion from that is that there's no value that you could pick that would be representative of any particular site that you might be working at. 00:01:39.000 --> 00:01:51.000 Furthermore, it's unclear which parameters or factors are responsible for that variation. So it's not something that you could easily, you know. 00:01:51.000 --> 00:02:03.000 With some other. Clarinet solvents, for example, you can look at KOC and the organic carbon kind of minimizes that variation. 00:02:03.000 --> 00:02:12.000 But that was not case for P fast. So, determining a site specific partition coefficient seems to be the more reasonable approach. 00:02:12.000 --> 00:02:26.000 In terms of modeling, so. It is possible. In some cases, it appears you can model this migration numerically. 00:02:26.000 --> 00:02:38.000 But it often requires measuring unusual parameters. Using specialized equipment using specialized laboratories. And that can be expensive and that can take a long time. 00:02:38.000 --> 00:02:47.000 Some of the factors such as the air water interfatial area may not be constant. You know, they can change depending on site conditions. 00:02:47.000 --> 00:02:52.000 So depending on the nature of the study you're conducting, you may need to take multiple measurements of these. 00:02:52.000 --> 00:03:07.000 You may need to measure that, you know, high flow. Precipitation events and other times this is a list of some of the parameters suggested for billing a comprehensive model. 00:03:07.000 --> 00:03:14.000 Which include things like the soil water partition measurements, air water, interfatial area, and interfatial absorption coefficients. 00:03:14.000 --> 00:03:24.000 That you can't get done it just a standard laboratory. So that would require some additional planning if you wanted to go that route. 00:03:24.000 --> 00:03:30.000 So our approach is to use a site specific. Soil water partition coefficient. 00:03:30.000 --> 00:03:35.000 And there's 2 kind of approaches that we looked at for this. The first is isymmetry. 00:03:35.000 --> 00:03:44.000 So this is installing a device to directly sample. Which gives you a snapshot of the leaching behavior at your site. 00:03:44.000 --> 00:03:50.000 These have the advantage that you can capture seasonal variation depending on when you collect your sample. 00:03:50.000 --> 00:04:02.000 But it does require longer sampling timelines. A lot of these require some period of equilibration after installation before you can collect a sample. 00:04:02.000 --> 00:04:11.000 And then when it's actually time to sample, they may need 24 h or longer of you pulling a vacuum to actually collect the sample. 00:04:11.000 --> 00:04:18.000 The volume of sample you're collecting. Each time can be unpredictable. It requires. 00:04:18.000 --> 00:04:32.000 Generally installing in a high formable area to get a sample and depending on precipitation or other conditions, you may get 5 milliliters and you may get 200. 00:04:32.000 --> 00:04:39.000 And they generally rely on pulling a vacuum to suck the water into the bysimeter. 00:04:39.000 --> 00:04:50.000 Which could volatileize some of the So they may not be suitable for everything. Laboratory leeching kind of the more standard method. 00:04:50.000 --> 00:04:57.000 Is, you know, you're generating a leachate from the soil in the laboratory. 00:04:57.000 --> 00:05:07.000 If could be more of a worst case scenario rather than looking at. The actual leeching or into the port water you're looking at what could be reaching out. 00:05:07.000 --> 00:05:15.000 But it has the advantage that you can target it to a specific depth or multiple depths. And the field work is a lot simpler. 00:05:15.000 --> 00:05:23.000 You just collect the soil sample and the rest you can perform. At your leisure. And so the laboratory leaching is really what we're. 00:05:23.000 --> 00:05:28.000 Interested in that's kind of the method we're going with but of course there may be other methods that are appropriate. 00:05:28.000 --> 00:05:34.000 You know, there's we've heard a lot about passive samplers today and we've been going to that at all. 00:05:34.000 --> 00:05:41.000 There's also kind of 2 main approaches to these leaching methods. We heard earlier about leaf. 00:05:41.000 --> 00:05:56.000 And then the synthetic is, just a simple extraction. You're using basically a rain simulant, which is pH adjusted DI nice water as your distraction fluid. 00:05:56.000 --> 00:06:04.000 You're at a 21 liquid to solid ratio. And this has the advantage that it's already being used in a regulatory capacity. 00:06:04.000 --> 00:06:13.000 And then leaf is. 4 independent assessments you could perform. Any of them or all of them. 00:06:13.000 --> 00:06:22.000 2 of them require multiple batch extractions, which is 1313 13. The, in the function of pH. 00:06:22.000 --> 00:06:31.000 On partitioning and 1316 which is liquid solid ratio. And then the other 2 methods are a little more unusual. 00:06:31.000 --> 00:06:37.000 One is the call method. And then one is the monolithic or compacted Method. 00:06:37.000 --> 00:06:51.000 Which are they're a little more complex to carry out and it may be harder if you're relying on a contract laboratory to find someone to do that for you. 00:06:51.000 --> 00:06:58.000 Earlier this year, Jennifer Golfo presented some data on their leaf assessment. 00:06:58.000 --> 00:07:11.000 And one of their results was that the pH. Of the extractant actually has really little effect on leaching or the E fast compounds shorter than 8 carbons. 00:07:11.000 --> 00:07:19.000 Oh, you can see that in the top graph there. And also that reducing that liquid to solid ratio. 00:07:19.000 --> 00:07:26.000 A leaf ranges from I think one to 10. Versus SKLP, which is 20. 00:07:26.000 --> 00:07:39.000 When you reduce that ratio to have less liquid. You're just generating a less conservative estimate. So in our, in our opinion, SPLP remains. 00:07:39.000 --> 00:07:48.000 The simplest method for doing this estimation of leaching potential without requiring larger number of samples. 00:07:48.000 --> 00:07:57.000 And with relatively. Representative parameters. Also noted on these 2 plots. So. 00:07:57.000 --> 00:08:03.000 The pH doesn't have much of an effect for the shorter compounds, but it does for the longer compounds. 00:08:03.000 --> 00:08:10.000 The highlighted blue area is The starting pH of the SPLP extraction fluid. 00:08:10.000 --> 00:08:15.000 And because those are unbuffered, generally they'll adapt to whatever the pH of the soil is. 00:08:15.000 --> 00:08:28.000 So you can see in our experience, the pH tends to rise to. Somewhere between maybe 6 to 8, depending on the soil. 00:08:28.000 --> 00:08:37.000 So you will end up with a longer chain. Closer to that range where you're getting the full extraction. 00:08:37.000 --> 00:08:49.000 That you see in the leaf with the different pHs. But we are also looking further into the variations into the liquid to solid ratio. 00:08:49.000 --> 00:08:55.000 There's also been some comments that perhaps SBOP is too aggressive an extraction. 00:08:55.000 --> 00:09:04.000 It's important to remember that it's not intended to represent. The conditions that you would see in the beta zone. 00:09:04.000 --> 00:09:09.000 The physical agitation, which The method calls for end over and tumbling. Will cause particle size reduction. 00:09:09.000 --> 00:09:30.000 You may see more leeching as result of that than you would see. In situations. As well as the saturated conditions of the the SPLP does eliminate air water interfaces that we know are important for PFash retention. 00:09:30.000 --> 00:09:41.000 And the high liquid solid ratio favors partitioning into the liquid phase. But It's looking at long-term reaching potential with the SPLP. 00:09:41.000 --> 00:09:50.000 You're not trying to say this is exactly what's going to happen. You're trying to figure out what could happen over the long term. 00:09:50.000 --> 00:10:03.000 And it's important to also note that it's not the worst case scenario. Because your extraction fluid is essentially just water, there are conditions where you may see. 00:10:03.000 --> 00:10:13.000 Even the, you know. Precipitation or that is more extreme than this extraction fluid. 00:10:13.000 --> 00:10:19.000 And so it's important to interpret. Your results from SPLP appropriately. 00:10:19.000 --> 00:10:29.000 So our specific method is slightly modified from the textbook method. We kept the liquid to solid ratio of 20. 00:10:29.000 --> 00:10:41.000 We're mixing for 18 h to generate our and we're using extraction fluids that are GI and ice water, the H adjusted to either 4.2 or 5 point O. 00:10:41.000 --> 00:10:47.000 But we've modified it to use only key fast-free materials or, you know, containers. 00:10:47.000 --> 00:10:59.000 Primarily and a P fast free water. We've reduced the sample mass. The normal method calls for a hundred grams of soil and 2 liters of extraction fluid. 00:10:59.000 --> 00:11:14.000 We're doing a tenth of that, so 10 grams of soil and 200 mills. We remove filtration so you can see these bottles are before and after centrifugation and that's the only step we do prior to submitting for analysis. 00:11:14.000 --> 00:11:23.000 And then we're also, we've tested for alternative extraction. Which I will talk about a little more later. 00:11:23.000 --> 00:11:30.000 So we first implemented this at the Dallas Superfund site. This is in, Pennsylvania. 00:11:30.000 --> 00:11:38.000 It's a former site of a furniture they applied a Stain repellent to fabric. Oh, P pass-based thing repellent. 00:11:38.000 --> 00:11:46.000 And it's co contaminated with tricloroethylene, but there's no use of atrip left the site. 00:11:46.000 --> 00:11:51.000 And you can see on this map, we've got 2 soil cores that we collected. 00:11:51.000 --> 00:12:03.000 From inside of the what's now a warehouse. We believe these are close to the source zone, where they were applying this stain repellent. 00:12:03.000 --> 00:12:10.000 So we've gone, under the concrete slab, like these, they're the 2 soil cores, soil core one. 00:12:10.000 --> 00:12:18.000 Is about 15 feet. In depth and soil core 2 is about 18 feet. And we've subdivided them into. 00:12:18.000 --> 00:12:28.000 Samples that should represent about one foot of depth each. This is 15 samples for core one and 20 samples for 4 2. 00:12:28.000 --> 00:12:36.000 And then there's also 2 monitoring wells very close by. And a variety of monitoring wells around the site. 00:12:36.000 --> 00:12:41.000 You can see 2 of these wells are highlighted. Mw, 32 and MW. 00:12:41.000 --> 00:12:53.000 33. Just because the we've kind of looked at the groundwater data versus our SKLP with these 2 in particular just because of how adjacent they are. 00:12:53.000 --> 00:13:01.000 The analysis portion. We're using a targeted analysis. Direct inject method. Initially, this. 00:13:01.000 --> 00:13:08.000 We've had some improvements to the method since then, but with these initial set of samples. 00:13:08.000 --> 00:13:19.000 We had quantitation limits around, 100 part per trillion. And because of the Liquid solid ratio when you convert that back to soil concentrations. 00:13:19.000 --> 00:13:27.000 You're looking at a quantitation limit of 2 micrograms. This is the list of all the compounds we analyze. 00:13:27.000 --> 00:13:39.000 The vast majority we didn't detect in any of the samples. And 4 of them we regularly detected in, enough that we could kind of look at some trends. 00:13:39.000 --> 00:13:49.000 So those are the 4 that I'm gonna be talking about further. You'll notice there's a few that are not crossed off. 00:13:49.000 --> 00:13:58.000 Those are typically things we saw in maybe one or 2 samples. But it just wasn't enough to really look at kind of trends. 00:13:58.000 --> 00:14:07.000 And so here we have the frequency of detection. So this is just how often these compounds were detected in our extracts. 00:14:07.000 --> 00:14:17.000 Above the detection limit and above the quantitation limit. We see the same 2, the same sets of compounds from both soil cores. 00:14:17.000 --> 00:14:29.000 The concentrations tended to be higher from soil core 2 or one. And the compounds that we saw were similar to what we saw in the groundwater. 00:14:29.000 --> 00:14:34.000 So you have 4 ground water samples here, 2 from the monitoring wells, 32 and 33. 00:14:34.000 --> 00:14:40.000 We also collected some ground water from the bottom of the 4 holes, which we've labeled core one and 4 2. 00:14:40.000 --> 00:14:48.000 For the most part, you see essentially the same compounds in the groundwater that you see in the soil extracts. 00:14:48.000 --> 00:14:54.000 With a few exceptions, PFD EA in core one, for example. 00:14:54.000 --> 00:15:03.000 And then also, you know, these long chain compounds, throughout the soil course pretty much up the whole depth. 00:15:03.000 --> 00:15:08.000 And the sub-sampling we did allows for really looking at the migration profile of the P fast through the soil column. 00:15:08.000 --> 00:15:20.000 So you can see in core one and core 2 PFOA and PFOS are still concentrated right near the surface. 00:15:20.000 --> 00:15:28.000 And also with a lot of these compounds, you see a spike just above the groundwater level. 00:15:28.000 --> 00:15:38.000 And as you get deeper into the ground water, these concentrations kind of wash away that suggest there's movement from the soil into the groundwater. 00:15:38.000 --> 00:15:45.000 You can also expect there will be future groundwater contamination. We see, you know, these profiles are. 00:15:45.000 --> 00:15:53.000 Still moving down. But we still need to look further into the effect of age precipitation. 00:15:53.000 --> 00:16:03.000 And the method of kind of a P fast application onto the soil. One thing to note here is that these cores are from inside of a building under a concrete slab. 00:16:03.000 --> 00:16:08.000 So, you know, they're not getting rained on. There's no precipitation infiltration coming. 00:16:08.000 --> 00:16:16.000 Which may be why some of these launching comments are still at the surface. So we just seem to look further into that. 00:16:16.000 --> 00:16:28.000 The next step is to translate these extract values into risked groundwater or groundwater concentrations. 00:16:28.000 --> 00:16:33.000 The typical approach would be. Yeah, you determine some P fast concentration in a And then apply a deletion attenuation factor. 00:16:33.000 --> 00:16:50.000 The 20 to one ratio of SPLP is kind of designed to build that in. And so what we've seen is that If you take some of the, maximum concentration from these soil cores. 00:16:50.000 --> 00:16:57.000 And apply no dilution at all to that. It's reasonably similar to the groundwater concentrations. 00:16:57.000 --> 00:17:14.000 So you can see core one and core 2 here are the groundwater concentrate or the soil core concentrations, extract concentrations, versus the groundwater in monitoring well, 32 and 33. 00:17:14.000 --> 00:17:36.000 And they're reasonably close. What were the 4 compounds most commonly detected? But, you know, this is based on the maximum concentration we saw from the And if you were to Select the single depth to perform SGL beyond or maybe do a homogeneous mixture of an entire soil column. 00:17:36.000 --> 00:17:46.000 You may not know where that maximum depth is. And you would also need to look at the specific PFAS mixture you have at your site. 00:17:46.000 --> 00:17:54.000 The ones that we saw were each C 6 to C 8 primarily. So if you had more of the short chain compounds. 00:17:54.000 --> 00:18:03.000 It may be a whole different situation. And, you know, this was just one site, so it's not clear this was just a coincidence that this. 00:18:03.000 --> 00:18:12.000 Relationship existed. So we've got some additional research sites. So the first one is the, Air Force base. 00:18:12.000 --> 00:18:22.000 Which is locating central Alaska. It's been listed since 1989. For, B-tax and chlorinated solvents and PCPs. 00:18:22.000 --> 00:18:33.000 In 2015 they detected. Ground water and drinking water be fast contamination and some runway extension projects. 00:18:33.000 --> 00:18:44.000 Generated 130,000 cubic yards of contaminated soil. Which you can see in that bottom picture under that black tart are piles of contaminated soils. 00:18:44.000 --> 00:18:54.000 And then the groundwater plume you can see extends essentially from the base to a neighboring town. 00:18:54.000 --> 00:19:03.000 And one of the advantages of this site. Is that the Air Force Civil Engineer Center is conducting a leisure study. 00:19:03.000 --> 00:19:12.000 So they installed, 22 licenses at 9 locations. The goal was one to 3 lysimeters at each site. 00:19:12.000 --> 00:19:23.000 So target different depths. And they collected 4 rounds of samples over the summer. I believe they collect the black ones in. 00:19:23.000 --> 00:19:31.000 September or October of this year. And while they were installing them, we got co-located soil samples. 00:19:31.000 --> 00:20:01.000 That we can look at whether our SDLP method will produce consistent results with what we saw at Dalma a first site. 00:21:08.000 --> 00:21:16.000 We saw with. Valent where we were kind of looking at the whole soil column. 00:21:16.000 --> 00:21:24.000 And then we have 2 additional sites. So we recently went back to Valmont and collected 2 additional soil cores. 00:21:24.000 --> 00:21:33.000 This is 3 and 4 on the map which are just outside the building, but still underneath asphalt parking lot. 00:21:33.000 --> 00:21:35.000 And then we collected the samples. Near the surface and above and below the level of the ground. 00:21:35.000 --> 00:21:48.000 This is based on what we saw with the previous round where those were kind of the areas that we saw these higher concentrations. 00:21:48.000 --> 00:21:58.000 And they're still located within kind of that bloom. In the direction of groundwater. We also have some soils collected from the Jay Bear. 00:21:58.000 --> 00:22:08.000 These were. Confederate soil that was extraction, excavated for construction projects that they had stockpiled. 00:22:08.000 --> 00:22:16.000 So we don't really have as much information about this specific. Location that these samples came from. 00:22:16.000 --> 00:22:23.000 So we're just hoping that these sites will help us kind of. Make this, method more robust. 00:22:23.000 --> 00:22:34.000 We so there's a few additional modifications. So obviously we wanted to avoid filtration and we wanted to look at, or avoid filtration. 00:22:34.000 --> 00:22:39.000 Yeah. But there's some other things that we're looking at that we thought might help, but. 00:22:39.000 --> 00:22:47.000 We weren't sure. So the first was different extraction fluids. The SBLP kind of default is DI nice water. 00:22:47.000 --> 00:22:56.000 But we've also got methanol with ammonium hydroxide This is designed to be a total extractant. 00:22:56.000 --> 00:23:06.000 So. We're discussing early, Troy mentioned earlier that with. One of the advantages of leaf with the liquid solid ratio is you can see. 00:23:06.000 --> 00:23:11.000 Whether you're. Extraction is complete or not. This is another way that we're kind of looking at that is. 00:23:11.000 --> 00:23:16.000 The methanol should extract all of the PFAS in the soil. And you can compare that with the SPLP. 00:23:16.000 --> 00:23:26.000 Extraction. We tested 2 extraction fluids. Sodium by carbonate as a groundwater analogue. 00:23:26.000 --> 00:23:35.000 And calcium nitrate. There's some research suggesting that. Calcium in solution can have a bridging effect that may. 00:23:35.000 --> 00:23:46.000 Retain P fast too soil particles so we wanted to see whether that had any effect. And then, high pH, sodium petroleum solution. 00:23:46.000 --> 00:23:56.000 This is Buffett, so rather than. Adapting to the peach of the soil it should remain somewhere around 9 00:23:56.000 --> 00:24:10.000 And so this is what we see from soil core one. So each of these kind of collections of graphs is one of the subsamples from core one at Valmont. 00:24:10.000 --> 00:24:21.000 And then the 2 5 bars of different colors are the 5 extraction fluids. So the top is the SDLP, the bottom is the methanol this one not particularly exciting. 00:24:21.000 --> 00:24:26.000 Core 2, you get a little bit more variation. This is just for PFOS. 00:24:26.000 --> 00:24:34.000 Just because it was a little more interesting to look at. And yeah, so, you know. 00:24:34.000 --> 00:24:46.000 We see the Teta Boris solution did not perform particularly well. There wasn't a lot of variation between the SPLP, the sodium bicarbonate and the calcium nitrate solutions. 00:24:46.000 --> 00:24:53.000 But one thing we did notice is that. The methanol concentrations were generally not higher than. 00:24:53.000 --> 00:25:02.000 What we saw the other extraction fluids. So this suggests that the methyl either isn't working to conduct a total extraction. 00:25:02.000 --> 00:25:11.000 Or that the standard SPLP solution or these other executive fluids are essentially all performing a total extraction. 00:25:11.000 --> 00:25:20.000 So this graph we've got the X-axis is. The soil concentration calculated from the method all extracts first. 00:25:20.000 --> 00:25:33.000 The, alternative extracting fluids. And the dotted line is one to one. So we would expect to see all of those points would be on or below that one to one line. 00:25:33.000 --> 00:25:39.000 But instead we see kind of a mixture across the whole system. Which is not necessarily a problem. 00:25:39.000 --> 00:26:05.000 So. If your goal is just to look at the leaching potential or the risk to groundwater, this may be fine to say that the SPLP is doing the total extraction and you don't need to do any If you're goal is specifically to conduct to calculate a site specific soil water partition coefficient. 00:26:05.000 --> 00:26:12.000 Then this isn't going to work because you're legal fraction and your total fraction are gonna be the same. 00:26:12.000 --> 00:26:24.000 So you would need to either, look at another method of getting your reachable fraction or adjust this method to be more suitable for that. 00:26:24.000 --> 00:26:35.000 And. So this is where we looked a little bit into the extraction ratio. So leaf does extraction ratios of 10 down to I think one. 00:26:35.000 --> 00:26:45.000 Or even lower. But in this case, we did, 20, which is kind of the standard, 15, 2, and one. 00:26:45.000 --> 00:26:59.000 So one to one would be 10 grams of soil, 10 grams of extraction fluid. The idea being that as you reduce the volume of extraction fluid, the strength of the extraction fluid would be more important. 00:26:59.000 --> 00:27:13.000 So the top we're just looking the top, chart. We're just trying to see when does this ratio of the concentration in the SPLP extraction fluid versus the concentration in the methanol split. 00:27:13.000 --> 00:27:27.000 And then in the bottom we're looking at. How low a volume of extraction fluid and you use where the methanol is still getting that essentially 100% extraction. 00:27:27.000 --> 00:27:40.000 And for the Valmont soils. It looks like this ratio of 2 actually came out really well where you're getting that separation between the SPLP and the methanol extracts. 00:27:40.000 --> 00:27:51.000 But the methanol extract is still getting essentially a hundred percent of the P fast out. But again, this is one site and we need to kinda extrapolate further and see. 00:27:51.000 --> 00:28:08.000 Whether this holds for other types of soil. And mixers of and yeah, so. Essentially what we found is that with very few modifications, the SPLP does seem to provide a good framework for. 00:28:08.000 --> 00:28:21.000 Looking at these this impact of groundwater assessment And it provides some flexibility to address project specific needs. We looked at different depths, you know, if you're interested in. 00:28:21.000 --> 00:28:31.000 Looking at those. Really fine grain looking at reaching from different depths can do that you can kind of target specific areas. 00:28:31.000 --> 00:28:35.000 Validation additional sites is ongoing. And it looks like they've more complex extraction fluids. 00:28:35.000 --> 00:28:45.000 There's not really any benefit to using them from what we've seen initially, but we're still looking further into that. 00:28:45.000 --> 00:28:54.000 And that there's still optimizations available. For. Your specific intended use. 00:28:54.000 --> 00:29:01.000 And. For questions, just the acknowledgment of a lot of the other people that help work in this project. 00:29:01.000 --> 00:29:08.000 From region 2 in region 3 in region 10. And, New Jersey, DP as well. 00:29:08.000 --> 00:29:16.000 And that's all I've got. 00:29:16.000 --> 00:29:23.000 Again, if there's questions in the room. 00:29:23.000 --> 00:29:45.000 Yeah, my question regarding using the KD values. And using a linear. And the question why do not use non- for the concentration, it is related between the KD as a factor where it is related to the 2 concentration use the N. 00:29:45.000 --> 00:30:02.000 Parameter where the end parameter will be dependent on other factors. Such as adoption disruption and other factors also understand the KD value is impact by PHH and many mineralogy and many other factors of their content as well. 00:30:02.000 --> 00:30:11.000 But for PHS. So we need to think about So option disruption and the free code has a big. 00:30:11.000 --> 00:30:27.000 Chapter actually regarding how you deal with this option the soft impactor and using nonlinear so your question is about essentially why we're using the linear rather than the. 00:30:27.000 --> 00:30:33.000 Look equation that has the end parameter as well. 00:30:33.000 --> 00:30:42.000 Or, rather why we're not looking further into if you have Abdulson and disor kind of adjustments. 00:30:42.000 --> 00:30:51.000 Sorry. He's asking if you're, are you asking about the linear versus a Friend like being a nonlinear with the exponential factor. 00:30:51.000 --> 00:31:03.000 So yeah, I think they, yeah, I agree with you the exponential factor is important. And then you could actually try and use it in the experiment. 00:31:03.000 --> 00:31:11.000 And when you take the field data, try to see how it fits. And but there are other conflicts question about variation. 00:31:11.000 --> 00:31:27.000 Of the physiology could varies actually. You need to look at the site how the variation and so on and then not tentatively you could use the initial non-linear phone so There's a couple of things in here. 00:31:27.000 --> 00:31:38.000 So in the. Initial study we we did look at kind of absorption versus disorption and laboratory versus field studies. 00:31:38.000 --> 00:31:46.000 And, I didn't go into it here, but what we did see is that, you know, there is that difference between. 00:31:46.000 --> 00:31:59.000 Field studies generally find more foil partitioning than laboratory studies. And these auction studies tend to find the same more partitioning to the soil. 00:31:59.000 --> 00:32:13.000 But you know, we couldn't there was no way for us to kind of it didn't narrow the range of KV or KOC values for each group, it merely shifted them up or down. 00:32:13.000 --> 00:32:22.000 And with the, find like nonlinear absorption coefficient. That does. 00:32:22.000 --> 00:32:36.000 Have kind of the same problem with the KV that you see. People will calculate it and they'll a number of study report that All of the values are between point 8 and 1.1 and it's essentially linear. 00:32:36.000 --> 00:32:45.000 And then one study will say that they calculated a value of point 2. And so you essentially end up in the same situation where you can't just find a literature value that's appropriate. 00:32:45.000 --> 00:32:52.000 You'll need to do some kind of site specific characterization. So in our case, we just. 00:32:52.000 --> 00:33:01.000 We, we didn't see the need for the nonlinear aspect at this point. As long as you're doing the site specific. 00:33:01.000 --> 00:33:08.000 Calculation. And 00:33:08.000 --> 00:33:18.000 Questions in the room? 00:33:18.000 --> 00:33:30.000 Okay. Thank you. That is our last speaker for the morning.