CHUCK NEWELL: Well, we've reached the final week of the course, and we'll touch on a variety of different topics during the week. We're going to start with a relatively new tool from ESTCP for determining if MNA is a good choice if you've got a site with chlorinated ethene, such like a PCE or TCE. DAVE ADAMSON: Yeah, it's this BioPIC tool. And this is developed by a whole host of experts in our field, Carmen Lebron when she was at the Navy, Todd Wedemeyer John Wilson, Fran Lawfer, Rob Hinchey, Mike Singletary. But like Chuck said, it's something sponsored by ESTCP. And it's a free and simple piece of software. But first, I know you really like acronyms, Chuck. So what do you think that BioPIC stands for? CHUCK NEWELL: I'm going to guess that Bio is biological or biodegradation, something like that. And then PIC, sort of went ahead here, but that's this pathway identification criteria. As an acronym aficionado, I like it because it tells you what the function of the tool is. It lets you pick which bio option's right for you. DAVE ADAMSON: Yeah, I knew you'd like it. But anyway, let's talk about why this tool was needed. So Carmen Lebron and John Wilson have given some good presentations on this topic in the past before. So some of this material gratefully borrowed from them. But anyway, remember that we've talked a lot about how MNA is sort of predicated on gathering these lines of evidence that natural attenuation is occurring and that you understand why and how fast it's occurring. So this, again, it's a tiered approach. It's described in this MNA directive, 1999. That's the document here on the right that we've discussed a lot before. But here's what this document says in terms of these lines of evidence. So first, "groundwater data that demonstrate a clear and meaningful trend of decreasing contaminate concentration over time at appropriate monitoring locations." CHUCK NEWELL: OK, so that's line of evidence one. Line of evidence two, that this "hydrogeologic and geochemical data can be used to demonstrate indirectly the types of natural attenuation processes and the rate that these process will reduce contaminants to required levels." DAVE ADAMSON: So BioPIC is basically designed to be a quantitative framework to really address these lines of evidence, particularly the rate information. Authors call it "a systematic approach to evaluate whether MNA is an appropriate remedy based on site-specific conditions." So I've pasted the splash page for the tool right here. And here's some easy search terms for the download. CHUCK NEWELL: So remember, that this is free software built using an Excel platform, so not a lot of barriers for people to go out there and just download and use that. DAVE ADAMSON: Yeah, and I'd also like to point out that this tool isn't just about MNA. Another thing that it does is it's basically providing you a basis for choosing between three different biologically based remedy options. So we're talking about biostimulation, so just adding substrate; bioaugmentation, adding bugs and maybe some substrate; or MNA, so no bugs or substrate. CHUCK NEWELL: OK. So how does it work? DAVE ADAMSON: Well, the analyses in BioPIC are designed around ensuring that the plume will not impact a receptor. MNA's not going to be feasible if the current situation won't protect the receptor. CHUCK NEWELL: OK, and then let's look at the slide here and the graphics illustrate this point. On the left panel, you want to know that you're not going to see plume expansion. And on the right, you want to make sure that the concentration at the source, that highest concentration, is going to decrease to acceptable levels by the time the groundwater travels to any downgrading receptors. DAVE ADAMSON: Mhm. And BioPIC directs you to use a simple Groundwater Fate and Transport model determine the rate your site. You use something like BIOCHLOR And basically, you're using the field data to determine if the necessary rate of degradation that could achieve your goal. CHUCK NEWELL: OK, then what BioPIC does, what's new, is that it can confirm whether or not that rate is consistent to what's been seen before at other sites. It examines multiple pathways and the rates associated with them based on a particular set of site specific parameters and determines whether the rate at your site make sense and supports MNA. DAVE ADAMSON: OK, so this next slide is basically showing, then, what pathways are considered within BioPIC, so it includes both complete reductive dechlorination, anaerobically, all the way to ethene. And partial reductive dechlorination does something like cDCE. It's also got aerobic biological oxidation in there. It's also got abiotic degradation, which we talked about way back in week three. And then we were talking about some of the ways that abiotic degradation rates could be estimated or ground truth using existing data on parameters like magnetic susceptibility. So all that information was coming from BioPIC. CHUCK NEWELL: So now if we look at the right hand side, we have a list of all the parameters that were found have to have a direct correlation to the attenuation rate, meaning that the authors were able to plot the attenuation rate versus the concentration of these parameters and see a statistically significant relationship. So it turns out that the important parameters were-- sort of the drum roll here-- Dehalococcoides density, magnetic susceptibility, iron sulfides, methane, and ferrous iron. Now, it's important to note that some of the other parameters I looked at things, like dissolved oxygen, ORP, and total organic carbon, didn't have that statistically significant relationship and the ones on the list here are the key ones. DAVE ADAMSON: Yeah, yeah. So that's a basic description of BioPIC is trying to do. And Chuck, do you want to look at what the framework looks like? CHUCK NEWELL: Sure, let's see what this whole decision tree looks like, so bring it up here. Quite a few different boxes in here. DAVE ADAMSON: Yeah, you asked for it, so here it is. Obviously, there's a lot going on in here. So just be glad that the tool-- it's the job of the tool to actually walk you through all of this thing without as much effort as it might take otherwise. Maybe just simplify-- zoom in on this first part. This is sort of the decision, where it points you in which remedy you might be selecting. CHUCK NEWELL: OK, so I can see that better. So this is the point where you're deciding on which of these primarily biological options are right. You start out by determining if natural attenuation meets your goal. If attenuation is occurring, and if your receptor is protected, and there's no indication at this point if it's going to expand, now if that's not the case, then this takes you automatically to the left where you need to go through some sort of biostimulation or bioaugmentation. DAVE ADAMSON: Mhm. Yeah, and since we're talking about MNA in this course, let's assume that the goals are currently being met with MNA. So the concentration data is super convincing, and there's no clamoring for additional evidence, then maybe you're lucky and the tool will direct you further to the right. And then you say, MNA without the second line of evidence. But if you need more evidence and answer yes, it's going to take you down basically the rest of the tool where sort of the heart of the new information is. And that's where you're looking at whether or not the rates make sense. CHUCK NEWELL: OK, so how about for the next few minutes, we're going to go take this for a test drive? Let's launch the tool and see what it does for us. DAVE ADAMSON: All right, let's switch the screen over. OK, Chuck, well here's the BioPIC tool. Here's that splash page we showed before. And so, you know, if you also wanted to look at the flow chart, it's there as well. And so let's just go through a little short clicking around. So let's hit Start on here. And basically this is taking us through the flow charge. It says, does natural attenuation currently meet the goal? CHUCK NEWELL: We're going to say Yes here, right? DAVE ADAMSON: Yeah, yeah. But remember, this is a tool for when you need additional lines of evidence. So it's going to say, is the EPA second line of evidence required? So we're going to say that yeah, and maybe let's take a look at something like DCE, OK? CHUCK NEWELL: OK. DAVE ADAMSON: All right, so we'll click Yes on that. And so the next question is, DCE present? CHUCK NEWELL: Let's say Yes. DAVE ADAMSON: Yes, yes, since that's what we're interested in. Is DCE degrading? CHUCK NEWELL: Let's go ahead and say Yes. DAVE ADAMSON: Yeah, let's say Yes. Now it's going to take us through sort of these rates versus processes. And so the first thing on here is, does DHC density explain the DCE rate constant? So DHC-- CHUCK NEWELL: Dehalococcoides, the dechlorinated bacteria. DAVE ADAMSON: OK, so sort of the way you can go about looking at this is click on that Decision Criteria button. It sort of walks you through why you're sort of doing this. But BioPIC has then these modules on here where they develop these correlations. So let's open one of those. They've got various ones here. Let's take a look at the one for Dehalococcoides. As we open this up, we sort of see that it's got this input screen with these blues. And what are you entering into these blue cells, Chuck? CHUCK NEWELL: Oh, that's the first order rate coefficient. DAVE ADAMSON: OK, so we've got one for cDCE here and then maybe the Dehalococcoides concentration, gene copies per liter. And so then it gives you an answer. And in this case, it says your rate constant is lower than expected. So maybe it's not really the explanation here. You can click over and look at the actual plot of these things. And the way that the authors have done is, they've got these blue areas where these correlations are high confidence. If you fall outside of that blue area, maybe not enough evidence to support this process. CHUCK NEWELL: So you're not in the blue zone here. That's a problem. DAVE ADAMSON: That's a little bit of a problem on here. So let's close this one out and take a look at something else. And so let's go back to our guided tour. OK, so in this case, the DHC density didn't explain our rate constant. So maybe let's answer No. And then it takes us in another module. So we're looking at magnetic susceptibility expanding the rate constant. So let's look at the decision criteria it walks you through here. But again, we're going to maybe go actually into the spreadsheets. So they have separate one for magnetic susceptibility. CHUCK NEWELL: Goal's to get in the blue, is that right? DAVE ADAMSON: The goal's to get in the blue. So again, these input screens-- in this case, we've got our same rate coefficient in here. We've maybe got a magnet susceptibility thing from a lab. And so let's see what it says and click back onto here. And again, these numbers put us pretty squarely in that blue area, right? CHUCK NEWELL: Looking good, right? DAVE ADAMSON: Looking pretty good. So let's accept that. We're going to go back to our guided tour here. We're going to answer Yes to that question. And what does it say? CHUCK NEWELL: It says their suggestion that the quantitative line of evidence for abiotic DCE degradation. It helps you. DAVE ADAMSON: We met it. So end of pathway identification, so that's the information you get out of this tool. CHUCK NEWELL: Cool. DAVE ADAMSON: Well, that wraps up our look at BioPIC. But let's finish with a summary of a few of the key points. This is a free online tool that helps decide if MNA is right for your site. CHUCK NEWELL: OK, and if MNA is not appropriate, it helps you decide between biostimulation and bioaugmentation. DAVE ADAMSON: It uses correlations between parameters concentrations and known attenuation rates to determine which processes can explain field rates.
