Groundwater U 2024: DOE demonstrates in-situ pilot study at SSFL

Material storage area. And this is what you're seeing right behind me. You see here, the block diagram shows a little bit different here. This weathered sandstone behaves more, it has more pores in it, so you're able to get more flow through that. But we have many different wells. As you can see, these yellow pedestals behind me are the various wells that we have in the HMSA. And this is where we have, DTSC has recently approved a pilot treatment for in-situ or in-place treatment. So folks who were on the call on Thursday for Groundwater U heard a little bit about this. But here today, we have a demonstration of how this might work. Now, before I get into this, let me give the not-to-scale disclaimer. We've now tilted our groundwater. Yep. So, and obviously, we have rice here. This is not rice out here. This is not to scale. This just demonstrates a few of the concepts that we're talking about. The media we have here is going to allow flow a lot more freely. So what you could think about this is, is you're really zooming down into, if you were seeing these pores in the ground, this would be really, really, really close. But what that allows us to do here is this lets us show you in a time scale of this half hour that I have with you lovely folks today, what's going on, as opposed to the months or years or longer treatment that we're doing up here. Let's see. How do we want to do this? I have practiced this with two hands. Ryan, why don't you see if we can add some of our TCE. That's why we had red as the TCE. So we're going to add some TCE. Tell me when to stop. So let's get it about halfway between the two, and then let's add some to the other well as well, because we've got, we want to be able to see some large plumes in here, and then we can show these two different methods that we're, that we were talking about. So again, the demonstration purposes, this is not how we injected our TCE here. This is just for demonstration purposes. But we want to show you, yeah, so you can see the one, this has, you can see where the water level is, and let's turn it a little bit more because the sun moved a little bit. If it's in the sun, you can maybe see it a little bit better. So, but you can see in the wells, the wells will collect the water, and you'll see a higher concentration. And so, right, yeah, let me, because I, one of the things that we were doing in the FSDF is we were doing a pump and treat. And so here we have our pump, and we would be able to go in, and you'd be able to pump out the TCE. Now, I want you to notice, when it first came out, it was darker red. But as I continue to pull it out, it gets lighter and lighter, right? So what's happening there is, that's just showing that when you have higher concentrations of TCE, pump and treat is a remedy that makes sense. That's what we would want to evaluate. So we bump this, we would, in fact, even over there, we have a container that holds the water that we've pulled out that we take off-site for testing and treatment. So we'll go ahead, and we'll, we'll treat this TCE later. But then, so that's the pump and treat we were doing over in the former sodium disposal facility. So, and let me just take a look at what we got. So we've got a bigger plume here. The other way we wanted to do is in situ, or in place. And this would, where we'd be taking these amendments, and maybe Ryan, as I do this, you can tell, you can talk to him a little bit about what amendments we would be using in our HMSA to create that reductive environment that wants to dechlorinate those chlorinated solvents, that TCE to DCE to vinyl chloride, and then to ethene. So we want to see if we can use this, these amendments that Ryan's going to tell you about, to dechlorinate. Yeah, so you'll, and you'll hear more about this later, because the other parties are evaluating similar technologies. So what we're proposing to add here is an emulsified vegetable oil. So it's a food grade carbon substrate that stimulates the biological degradation. So that's the reductive dechlorination that we just saw, that goes from TCE all the way to ethene. We're also proposing to add a chemical reductant, a form of a zero valent iron, which also reduces TCE. The pathway is a little bit different. But one reason, I'm actually glad the question was brought up about the daughter products, because by adding both biological and chemical reductants, it provides a more robust treatment, because there's two degradation mechanisms that happen. So it greatly reduces the chance of accumulating like vinyl chloride. It promotes degradation to the dissolved gases in a more robust manner. And so, yeah, what Josh just showed is, obviously, it's very simplistic, but a well is put in the ground, the amendments are injected into that well, they disperse away from the well, and then the reactions start to happen over the course of weeks to months. And then we monitor periodically to see how it's going. And I wanted to show the injection well and the monitoring well. One of the other reasons we had two wells in this demonstration is we have the injection well, where we know the influence, but we're not certain the extent of the influence of those amendments. And so when we have a second well here, maybe I can ask my lovely assistant, right, to go into the monitoring well, so this monitoring well, and then we can see and we would be able to test, obviously, here. I don't think the sphere of influence quite reached between the two of them, but as we start pumping in this demonstration, we might be able to extract some of those daughter products. Let's see, are we getting to blue yet? I think it's starting to, yeah. But this is another reason why we're conducting this as a pilot at a small scale, because we don't quite know what that sphere of influence is yet. And you can see on the diagram, the HMSA pilot test on the poster number three, those red and those blue circles for the different areas that we're looking at, one of them is 15 feet, one of them's 20 feet. We want to understand what that sphere of influence for these amendments are, so we can best design an in-situ treatment that would work here. And we're not presupposing that this is going to be the solution. We're testing it out, we're seeing how well it works, and then we are going to design that based on the information that we get from this pilot.