WEBVTT 00:00:00.000 --> 00:00:20.000 Well, thank you all for joining today, both in person and online. My name is Kobe Lebanowski. 00:00:20.000 --> 00:00:24.000 I'm a project geologist with Western solutions. 00:00:24.000 --> 00:00:42.000 And today with me, Doug Geary, with Sky Tim, and today we are going to present to you delineation of a potentially tce impacted aquifer via airborne electromagnetic, geophysical survey, no boots on the ground. 00:00:42.000 --> 00:00:50.000 So this groundwater remediation project is that fee warn air force, base. 00:00:50.000 --> 00:01:07.000 Former Atlas E missile site 11. The formally used defense site and project is contracted through the Us. Army corps of Engineers, Omaha, District. 00:01:07.000 --> 00:01:18.000 So bulleted. Here are some of the points throughout the presentation, however, in the big picture the primary focus was to map potential off-site. 00:01:18.000 --> 00:01:25.000 Groundwater pathways in order to delineate the Tc extent in the unconfined water bearings. 00:01:25.000 --> 00:01:34.000 So what we're trying to convey is how an airborne approach to a geophysical investigation can be extremely powerful. 00:01:34.000 --> 00:01:38.000 Yeah, economically feasible tool to assist with identifying Viable. 00:01:38.000 --> 00:01:44.000 Well, locations. So first, I'd like to introduce the site. 00:01:44.000 --> 00:01:50.000 Speak to some of the conceptual site model or Csm updates and challenges. 00:01:50.000 --> 00:02:09.000 And while navigating this circle framework so I'll highlight some of the remediation system design, construction and overall performance, and and then I'll speak to the airborne electronmagnetics and bring dug up and and how it was applied to this site so then 00:02:09.000 --> 00:02:14.000 we'll go over the discuss some of the results and interpretation of the of the airborne data. 00:02:14.000 --> 00:02:28.000 It LED us to our ultimate goal, which was proposing well locations with intention rather than hope. 00:02:28.000 --> 00:02:40.000 So the site is located approximately 80 miles north of Denver, Colorado, up near the Wyoming border. 00:02:40.000 --> 00:02:54.000 Do you? In the early 19 sixtyties, Tricloro, Ethelene, or Tce, coordinate and solvent, was used to clean out the fuel lines in between missile readiness exercises. 00:02:54.000 --> 00:03:01.000 This spent, tce was disposed of. 00:03:01.000 --> 00:03:12.000 In a sump, where it was then introduced into the unconfined water bearing zone, and that something is located in the this yellow circle. 00:03:12.000 --> 00:03:19.000 Here, couple couple of key boundaries. That will be referenced. 00:03:19.000 --> 00:03:25.000 Throughout this talk. The blue box here is the on-site area, and in future slides. 00:03:25.000 --> 00:03:29.000 You'll see how it's been divided up into 2 separate areas. 00:03:29.000 --> 00:03:37.000 And we'll note that groundwater is moving Eastern from that source area. 00:03:37.000 --> 00:03:43.000 So towards the Usda property. There, as another boundary. 00:03:43.000 --> 00:03:48.000 There in red is Colorado engineering experiment station, or CC. 00:03:48.000 --> 00:03:51.000 And they are the current owners of the old Atlas 11 missile site and they run a light industrial operation where they do calibration and and flow testing. 00:03:51.000 --> 00:04:02.000 Services. Black lines are dividing adjacent property owners. 00:04:02.000 --> 00:04:16.000 So we have the private landowner number one, and note that half the eastern half of the onsite area is. 00:04:16.000 --> 00:04:38.000 Is actually the private property, and and then to the east, we have Usda property, which is downgrading it from the from the Tc impacted areas. 00:04:38.000 --> 00:04:47.000 Sorry, and this this large green box. Here is the area that we perform the airborne electromagnetic study. 00:04:47.000 --> 00:04:47.000 And again note the overlap of the on site area. 00:04:47.000 --> 00:04:54.000 Because this was by design. 00:04:54.000 --> 00:05:05.000 So this is a figure. Yeah, that portrays the historical Tc maximum on the site where each individual well back to 1,999. 00:05:05.000 --> 00:05:09.000 Its highest reported Tc. Value is plotted so. 00:05:09.000 --> 00:05:14.000 In a lot of like when we get snapshots through time. 00:05:14.000 --> 00:05:18.000 You'll never see the total footprint and you'll never see. 00:05:18.000 --> 00:05:23.000 Continue continuous plume, or a channel like a pencil line, flute. 00:05:23.000 --> 00:05:37.000 So, putting together something like this, and with the historical Max, could be very beneficial for any contaminated site. 00:05:37.000 --> 00:05:39.000 Okay. 00:05:39.000 --> 00:05:52.000 So notice orange diagonal boundary here. This is the 2 areas that I was alluding to in the last slide, we have the source area on the west in the east area and the east. 00:05:52.000 --> 00:05:54.000 The highest recorded value on site is much smaller than most of these other presentations. 00:05:54.000 --> 00:06:04.000 We've heard 1,100 micrograms per liter. 00:06:04.000 --> 00:06:10.000 That's found in this oval magenta area right near the Flame Pit. 00:06:10.000 --> 00:06:18.000 Of the site. So. 00:06:18.000 --> 00:06:42.000 So this pencil line plume is a result of the local geology, where we have varied paleo channels that provide the primary conveyance for the groundwater flow, and it's important because you can see that the orange here is anything above 250 micrograms per liter and anything 00:06:42.000 --> 00:06:45.000 in the blue is below 50, so you can see that most of the mass is concentrated in the center. 00:06:45.000 --> 00:07:00.000 In that Paleo channel. And the sudden, the sudden termination along this surficial road, Boundary County Road, 37 to the east. 00:07:00.000 --> 00:07:12.000 It's not realistic. We know that it continues onto the other side, which is why we need to investigate over that way. 00:07:12.000 --> 00:07:23.000 So this was the Isco, or insects, you chemical accident, remediation, system, design, and construction. 00:07:23.000 --> 00:07:26.000 So it is. 00:07:26.000 --> 00:07:40.000 Did. So. Let's begin with this schematic in the upper left, and how it works intend to do a recirculation system where we extract from a down a down ingredient. 00:07:40.000 --> 00:07:58.000 Well hold the water to the surface. We dose it with a prescribed volume of sodium per manganate, and then that dosed fluid is then injected into a well that's upgrading and acts as like a closed loop. 00:07:58.000 --> 00:08:14.000 Recirculation so, and and we're able to induce the gradient slightly we're able to control where our remedy is going. 00:08:14.000 --> 00:08:14.000 Smearing, and go kind of cross gradient to cover. 00:08:14.000 --> 00:08:25.000 A larger area. We can also target where that remedy is going. 00:08:25.000 --> 00:08:35.000 So like. I had mentioned before that eastern area is a a private landowner, and and his crop is grass, and this is cattle. 00:08:35.000 --> 00:08:45.000 Rangeland, and we didn't want to block off this 15 acre area, so it was unusable to him. 00:08:45.000 --> 00:08:52.000 So we ended up going subsurface with most of the most of the remediation system. 00:08:52.000 --> 00:09:09.000 So everything inside this orange rectangle box up here is all of our above ground equipment, and everything outside is subgrade, so that the so that the cattle still have their free range across that area. 00:09:09.000 --> 00:09:25.000 So a couple of unique features are the subsurface tubing, which was key through to last through the winters, and having that UV hit the tubing, you just have to replace it every year. 00:09:25.000 --> 00:09:35.000 But this way we've had this in place for almost 5 years now, and we have connection points. 00:09:35.000 --> 00:09:44.000 They're denoted by these green boxes here that are flush, mount, and even our wells are flush. 00:09:44.000 --> 00:09:50.000 Mount, and one of the one of the neat things about this is that everything is kind of set up. 00:09:50.000 --> 00:09:55.000 So as we receive data in, we can jump around well pairs to target the areas. 00:09:55.000 --> 00:10:14.000 And most wells have injection and extraction capabilities. And so what we found out was, recirculation is key, and. 00:10:14.000 --> 00:10:33.000 So a little bit on the remediation performance and it's really been optimized through the years to attain some of these unique features so it's a it's a context for. And it definitely is if we don't get sodium for manganese to come 00:10:33.000 --> 00:10:40.000 in contact with the tce. You're not gonna have any, and reduction or any reaction going on. 00:10:40.000 --> 00:10:52.000 So so we've successfully reduced the concentration of Tc in the source area by 98% as seen on this lower chart. 00:10:52.000 --> 00:11:02.000 Here. We've had a few events of rebound, but then we but to be like asymptotic conditions. 00:11:02.000 --> 00:11:21.000 And so we we had achieved response complete to the extent practicable, and we seized the system in 2,019, and in the eastern area we have reduced the Tc concentration by approximately 84%. 00:11:21.000 --> 00:11:27.000 And that is still ongoing in process in that area. 00:11:27.000 --> 00:11:34.000 So this I designed this remediation system to to implement up to 8 injection extraction. 00:11:34.000 --> 00:11:57.000 Well, pairs simultaneously, and we can achieve near 100% uptime throughout the field season, which is typically May through October in Colorado, weather depending, and the system is fully automated and who doesn't like automation. 00:11:57.000 --> 00:12:04.000 It's controlled by these upper and lower floats, which is located here that are in the like. 00:12:04.000 --> 00:12:13.000 The in between extraction and injection phase, where they're in a temporary holding tank. 00:12:13.000 --> 00:12:22.000 So maintaining water balance in there to keep injection and extraction on continuously is is pretty key. 00:12:22.000 --> 00:12:39.000 And again, that flexible design. As lab data comes in, we can move and target different areas in an hour and change up welfare. So it's a very, very convenient in that manner. 00:12:39.000 --> 00:12:59.000 So, and lastly, sodium, premiuminate is very, very effective in the groundwater, as far as it's persistent and its duration, as well so we've ended in 2,019 remedial efforts in that source area, however, this 00:12:59.000 --> 00:13:09.000 snapshot up here. You can see that the that the source area here still has a significant presence of sodium per manganate. 00:13:09.000 --> 00:13:17.000 And that's 3 years later. 00:13:17.000 --> 00:13:19.000 Okay, so the circle framework is, it's set up in a linear process. 00:13:19.000 --> 00:13:36.000 And as we all know, this process can easily be broken if the prior steps are not fully complete, and I think that's a lot of why we're here is, how can we do this investigation phase correct? 00:13:36.000 --> 00:13:43.000 The first time, and rather than having to come back to it multiple times. 00:13:43.000 --> 00:14:07.000 So we were awarded this project in 2011, and our original scope of work is here in the blue, and so we proposed a plan and march through, and once we've reached the remedial action remedial action phase, we had realized that that the initial csm 00:14:07.000 --> 00:14:15.000 had this Bolsey-style plume that was stagnant, and and it was like a perched waterbbing zone. 00:14:15.000 --> 00:14:37.000 And by 2,014 we reopen. We had realized that the plume was, in fact, moving towards the east, so we investigated the eastern area, that private property where the system was built, using seismic refraction, and that allowed us to Drill guide us to Drill a bunch of wells that 00:14:37.000 --> 00:14:48.000 we'd use as treatment wells. And here we are coming back to that again, because we need to look, beyond the other side of County Road 37. 00:14:48.000 --> 00:14:51.000 There, where? 00:14:51.000 --> 00:14:59.000 Where that plume just ended, at a superficial boundary. 00:14:59.000 --> 00:14:59.000 So? Why, an airborne, electromagnetic survey? 00:14:59.000 --> 00:15:11.000 So we've updated this Csm, and we have significantly reduced the Tc impacted footprint since 2,011. 00:15:11.000 --> 00:15:17.000 But we have yet to constrain and understand this full picture and extent of the plume. 00:15:17.000 --> 00:15:25.000 So do this unrealistic termination again, at the at the. 00:15:25.000 --> 00:15:31.000 This is really delayed at the end of the on site area on the eastern half. 00:15:31.000 --> 00:15:44.000 There. We wanted to take what we understand and know from the current onsite area to model and predict what's going on in the offsite area to the east. 00:15:44.000 --> 00:15:54.000 So, in order to simulate the extent of Tc impacts down gradient and data were synthesized, using geologic modeling software and can couple it with chemical transport code. 00:15:54.000 --> 00:15:58.000 Now this will give us a distance of how far the Tc. 00:15:58.000 --> 00:16:07.000 Could travel down gradient, but it doesn't necessarily tell us where. 00:16:07.000 --> 00:16:24.000 So if we go back to that ideology of of using a paleo channel-driven system and and oftentimes you will have topographic lows with paleo channels positioned vertically beneath them. 00:16:24.000 --> 00:16:35.000 We can use topographic lows as we did on the Usda property to help guide where this chemical transport code is directing it to. 00:16:35.000 --> 00:16:44.000 So it's it's kind of this am. Survey is going to verify whether this assumption is correct. 00:16:44.000 --> 00:16:48.000 Using topographic lows to identify paleotunals. 00:16:48.000 --> 00:16:57.000 And it's also going to see if there's anything that we missed, or if it's we we completely missed the mark. 00:16:57.000 --> 00:17:01.000 There. So we were tasked to delineate the Tcp. 00:17:01.000 --> 00:17:25.000 Plume in the area east of County road 37, with the the chief purpose to collect subsurface data in a noninvasive manner, with no boots on the ground, and to guide up the guide up to 6 well locations in order to delineate the extent of this c 00:17:25.000 --> 00:17:34.000 Clone. One last thing before we bring dung up that large green box that you saw was 800 acres, so we have to drill 6. 00:17:34.000 --> 00:17:58.000 Wells, and so drilling with intention again, rather than hope, is what we're aiming for, and we'll notice that this large plume or simulated plume area is approximately 2 miles. 00:17:58.000 --> 00:18:02.000 Conservatively speaking, is how far Tc. Could have gone downgradient. 00:18:02.000 --> 00:18:17.000 So this survey is intended to capture that whole area, to see to see what's going on, and Doug. 00:18:17.000 --> 00:18:18.000 Thanks, colleague. So basically, what is airborne? 00:18:18.000 --> 00:18:38.000 Electromagnetics, a transmitter and receiver, coil are slung below helicopter, and the transmitter generates a primary magnetic field by quickly turning on and off a current in the transmitting coil this primary field enters the earth. 00:18:38.000 --> 00:18:45.000 And energizes any conductive bodies in the ground, which then create a secondary magnetic field. 00:18:45.000 --> 00:18:52.000 When the primary magnetic field is turned off the secondary ground field is measured as voltages in the receiver coil. 00:18:52.000 --> 00:18:57.000 And this happens multiple times on a scale of microseconds. 00:18:57.000 --> 00:19:08.000 From these voltages. We can then calculate Earth resistivities as we can see in the animation on the lower left, the primary magnetic field moves down and outwards into the ground. 00:19:08.000 --> 00:19:14.000 And in this case it is moving approximately 150 millioners depth in 2 ms. 00:19:14.000 --> 00:19:21.000 So it does have very quickly. 00:19:21.000 --> 00:19:24.000 So how are we get from voltages to lithology? 00:19:24.000 --> 00:19:33.000 Once the voltages are converted in a resistivity they're plotted, and in this case, as a one d. 00:19:33.000 --> 00:19:42.000 Vertical section, rock types can be inferred by looking up textbook, earth resistivity ranges. 00:19:42.000 --> 00:19:49.000 Unfortunately, rocks and soil resistivities can vary from location to location, and they do have overlapping ranges. 00:19:49.000 --> 00:19:54.000 So it is difficult to determine exact mythology. 00:19:54.000 --> 00:20:06.000 So if we take a look at this color bar on the upper right, we can see that sand and gravel has the range of you know, 20 to 50 Ohm meters, but that's the exact same range as fresh water. 00:20:06.000 --> 00:20:12.000 So we have to figure out a way to be able to differentiate between these 2, so to help to do that. 00:20:12.000 --> 00:20:17.000 It's really critical to obtain geological data gather from boreholes. 00:20:17.000 --> 00:20:23.000 Local borals, and that gives us much more confidence in the with logical interpretation. 00:20:23.000 --> 00:20:27.000 And it's always best to locate these boreholes over the Em. 00:20:27.000 --> 00:20:32.000 Sounding, looks. 00:20:32.000 --> 00:20:37.000 This is a picture of the Em system. It's approximately 10 meters by 20 meters wide. 00:20:37.000 --> 00:20:42.000 The transmitter cable goes around the outside of the loop auxiliary equipment is mounted on it. 00:20:42.000 --> 00:20:55.000 We have GPS and inclinometers and laser altimeters, and this information is needed to properly convert the voltages into resistivities. 00:20:55.000 --> 00:21:05.000 The system transmits 2 types of waveforms. One is a low-strength triangular waveform shown here in blue, and this is designed to excite the near surface geology. 00:21:05.000 --> 00:21:13.000 The second waveform is a stronger square shape waveform, and that helps to energize deep geology. 00:21:13.000 --> 00:21:21.000 The orange traces here represent the secondary field from the earth, and you can see how it decays away. 00:21:21.000 --> 00:21:32.000 Slowly with time, and the dots represent the measurement point along that decay. 00:21:32.000 --> 00:21:39.000 Many factors going to the design of a survey, including some understanding of the geological trends. 00:21:39.000 --> 00:21:45.000 It's always best practice to fly perpendicular to the geological strike of interest. 00:21:45.000 --> 00:22:03.000 There's also many logistical and safety and faa regulatory concerns that have to be taken into account for this survey the Skytam, 304 system was chosen, as it's ability to map in the near surface a tight 50 meter line separation flown in a grid 00:22:03.000 --> 00:22:09.000 pattern was chosen to achieve high lateral and vertical data resolution. 00:22:09.000 --> 00:22:15.000 Flying height of 35 metres and a flight speed of 100 kilometers an hour. We're both chosen. 00:22:15.000 --> 00:22:23.000 Balancing safety concerns and data. Resolution concerns. 00:22:23.000 --> 00:22:33.000 The survey itself consisted consisted of 27 transacts, each about 2 and a half kilometers long, and covering an area of just over 800 acres. 00:22:33.000 --> 00:22:43.000 This resulted in about 60,000 E. M. Sounding locations, and at each location 50 readings were made, resulting in the approximately 3 million data points. 00:22:43.000 --> 00:22:55.000 These data points were then processed and converted into about 7,000 resistivity points spread across the area down to a depth of approximately 100 meters. 00:22:55.000 --> 00:23:05.000 At the start of a survey, a few calibration flights need to be flown, and then, before each flight there is a series of equipment checks that happen. 00:23:05.000 --> 00:23:14.000 Post-flight, the field cruise check that data quality and at the end of the day it is uploaded to the office geophysicist for further review. 00:23:14.000 --> 00:23:24.000 Once it is accepted, preliminary data can be forwarded to a cloud within 24 to 48 h on completion of the survey. 00:23:24.000 --> 00:23:29.000 The data is then converted into the threed model and provided to the client. 00:23:29.000 --> 00:23:38.000 Within about 6 weeks. 00:23:38.000 --> 00:23:51.000 Alright! So now that we have received our data package from Skytam, we, we took the data and dropped it into a geophysical software called Oasis Montage. 00:23:51.000 --> 00:24:10.000 This only produced the the same strike that the helicopter, that instrumentation, was flown in, so only we only received north-south profiles from this data, and up here is the cross section in the this is cross-section, or Profile. 00:24:10.000 --> 00:24:31.000 Number 2 from the flight transects, and so our our field goal posts, where we know that that Tc is migrating off-site is in between Dw. 77 and Tw. 00:24:31.000 --> 00:24:41.000 105 located up here, so, as you can see, it's we have a large area and we're trying to look at something that's pretty small, because we tried to cover that 800 acre area. 00:24:41.000 --> 00:25:07.000 So it's it's hard to follow the subsurface features in this manner, and very difficult to interpolate between the stacks to twod image that you can see in the lower right the simulated flow path we had that we had projected it's laid on top. 00:25:07.000 --> 00:25:15.000 This was you? Can start. You can kind of see some bounding areas, but it's loosely correlated at best. 00:25:15.000 --> 00:25:20.000 And so we knew this wasn't going to get us to our ultimate goal. 00:25:20.000 --> 00:25:33.000 So we modeled it 3D. And the the figure on the left is attempting to show the the 2 dimension north-south, trending profiles, and how we interpolate it into a. 00:25:33.000 --> 00:25:44.000 3D. Block that you can see up behind here. 00:25:44.000 --> 00:25:54.000 So that 3D. Grid interpolation was performed using a minimum tension splining algorithm within the Earth vision modeling software. 00:25:54.000 --> 00:26:02.000 And so now that we have a 3D. Volume or block of data that's been interpolated. 00:26:02.000 --> 00:26:14.000 Now we need to ground truth that data by calibrating the resistivity values from the survey to known groundwater conveyance features such as the bedrock and the water bearings, zone. 00:26:14.000 --> 00:26:29.000 And that's why we we intentionally overlapped part of our site area so that we had the capability for this calibration. 00:26:29.000 --> 00:26:53.000 So after the 3D model was calibrated, we could slice vertically in any orientation or configuration across that block, including nonlinear trance, sex, and to be able to look at the subsurface as shown in this fence diagram here on the right so most of our 00:26:53.000 --> 00:26:58.000 cross sections that we sliced into the Mono ran perpendicular to to what we were trying to see. 00:26:58.000 --> 00:27:10.000 Our simulated flow path. So you can even see kind of here this Y-shaped coming down here is our nonlinear path. 00:27:10.000 --> 00:27:19.000 That. Yeah. Alright, that we had simulated as part of the topographic lows in that area. 00:27:19.000 --> 00:27:28.000 And these we're attempting to highlight the potential paleo channels that we were seeing on site. 00:27:28.000 --> 00:27:50.000 As it continued to the off-site locations, as these flow paths would be the primary conveyance mechanism, where we would be most likely to see or pick up readings if we had to see in the groundwater. 00:27:50.000 --> 00:27:52.000 So I know there's a this is a pretty busy slide. 00:27:52.000 --> 00:28:02.000 There's a lot of information on here. And this is basically sums up our geophysical interpretation of the survey. 00:28:02.000 --> 00:28:07.000 Where, in the upper left, here our profiles, a. 00:28:07.000 --> 00:28:22.000 Through D, and these are north-south profiles that that are on site, and they intersect existing wells and. 00:28:22.000 --> 00:28:26.000 And then the the cross section. Your Profile. 00:28:26.000 --> 00:28:35.000 I is a continuation of that plume center line that was on site. 00:28:35.000 --> 00:28:43.000 So there is a little bit of overlap here, but it's projecting and extrapolating out onto the off-site area. 00:28:43.000 --> 00:28:49.000 So that is our most likely probable flow path. Leaving the site. 00:28:49.000 --> 00:28:52.000 But where does it go from there? And where does it take a turn? 00:28:52.000 --> 00:29:11.000 And cross-sections, profiles, E and F. Here are highlighted here in map view, and they they converge and truncate into the cross section below here, which is a profile. 00:29:11.000 --> 00:29:18.000 G, and these are our most likely flow paths that we that we have off-site. 00:29:18.000 --> 00:29:29.000 And but again, this, this area up above this black line, here the property boundary for Usda. 00:29:29.000 --> 00:29:35.000 We are unable to do any sort of invasive investigation on this site. 00:29:35.000 --> 00:29:51.000 So we would have to look beyond that site when we do, put or install our 6 wells, and in this bottom cross section here is just to show that the Am. 00:29:51.000 --> 00:29:58.000 Data is, is pretty spot on where we have shale and clays. 00:29:58.000 --> 00:30:12.000 Up above this this dry, loose sandstone is indicated on the boring log, and then under lane by more clays and sharedes. 00:30:12.000 --> 00:30:32.000 So together. This, the interpretation of these profiles indicate the most probable groundwater flow paths, and and they verify that the collection of subsurface data is feasible from the air with no boots on the ground. 00:30:32.000 --> 00:30:52.000 So the overarching goal for conducting this airborne survey is to have some direction of where we should place these 6 wells in this swath of land where we didn't really have an idea of of where the groundwater flow is going to go, especially when we didn't 00:30:52.000 --> 00:30:59.000 have access right across the road where we could track it and drill in a step out. 00:30:59.000 --> 00:31:07.000 Approach. So so we've placed our, our, our primary just mouse. 00:31:07.000 --> 00:31:17.000 It's funny. Okay, we we placed our number one drilling point right across the border where we have access to place a well. 00:31:17.000 --> 00:31:29.000 And I know we. I've said 6 wells, and I have 9 wells up here, but this is going to be an iterative process, and after we drill the first question, Did we encounter groundwater? 00:31:29.000 --> 00:31:34.000 If we did, did, we or after we do? A 24 turnaround time? 00:31:34.000 --> 00:31:47.000 Does that groundwater have tce in it? And answering those questions will guide us to how we would move out in our drilling process. 00:31:47.000 --> 00:32:12.000 But we've positioned most of them around that G profile where it's most likely that we will, that we will see groundwater, or at least the the channel or the conveyance mechanism for that groundwater body as a this unconfined zone is very distinctive 00:32:12.000 --> 00:32:22.000 as a purplish, weathered clay. Sitting on top of a black shale so we'll be able to tell if we're in the right area. 00:32:22.000 --> 00:32:34.000 And so these these wells have yet to be installed. We'll be doing that in a few months, and ultimately we will. 00:32:34.000 --> 00:32:55.000 We will verify whether this Aem was successful. We feel confident that it's going to be, and that we will be able to place their wells with intention rather than hope. 00:32:55.000 --> 00:33:04.000 And back to Doug. 00:33:04.000 --> 00:33:11.000 Thanks, Goby. I'm just going to talk about a few different sort of survey design considerations in this example. 00:33:11.000 --> 00:33:27.000 Survey was flown in Indian Wells Valley, California, to map the aquifer and to update the hydrologic flow model, and we can see this is the flight path here, and we can see in the lower left it's a much wider line spacing and this 00:33:27.000 --> 00:33:34.000 would be flown for a more regional overview of the area in the central area, where we have a region of interest. 00:33:34.000 --> 00:33:38.000 We did infill lines to get much more horizontal detail, and you also note that we flew in multiple different line directions. 00:33:38.000 --> 00:33:50.000 And that's just taking into account the local geological strike across the across the region of interest. 00:33:50.000 --> 00:33:53.000 Nonlinear transacts can also be flown. 00:33:53.000 --> 00:34:06.000 In this case they were carefully planned to go over areas of interest as well to avoid the numerous infrastructure in the area. 00:34:06.000 --> 00:34:12.000 It's important to note on this type of survey layout. 00:34:12.000 --> 00:34:21.000 Although the lateral resolution is going to be quite low. Vertical resolution along these lines is the exact same as we showed in the more detailed example today. 00:34:21.000 --> 00:34:33.000 System. Selection is also important. And it depends upon the goals of the survey whether it's for aquifer studies or bedrock mapping reconstruction, infrastructure, mapping. 00:34:33.000 --> 00:34:38.000 We're delineation of acid-mind drainage, or even just mineral exploration. 00:34:38.000 --> 00:34:47.000 We can see in the top panel the results from a near surface mapping system, and you can see subtle, resistive details on these hills. 00:34:47.000 --> 00:34:54.000 Near surface, and some subtle conduct, a flat-line bodies in the central region. 00:34:54.000 --> 00:35:05.000 Deeper mapping system shown in the lower panel did a very poor job of resolving these features, but it did pull out some nice conductive areas of interest at depth. 00:35:05.000 --> 00:35:11.000 So this is kind of what sort of resolution you can get, depending on which system you're picking. 00:35:11.000 --> 00:35:16.000 So in order to help optimize your survey, we will run some pre-survey modeling. 00:35:16.000 --> 00:35:25.000 To help select your your proper system. 00:35:25.000 --> 00:35:27.000 Hey! 00:35:27.000 --> 00:35:33.000 So thank you, and don't play gloves with hope placed with intention. 00:35:33.000 --> 00:35:42.000 All right. Any questions right again. If you're in the room, raise your hands. 00:35:42.000 --> 00:35:45.000 Go ahead! Bobby! 00:35:45.000 --> 00:35:52.000 Thank you for the presentation we have in ours, who are very much interested in subsurface characterization. 00:35:52.000 --> 00:36:03.000 My question. Now, using this technology of electromagnetic properties, it's impacted by pathology and structure as well as neurology. 00:36:03.000 --> 00:36:07.000 So. It is very sensitive to that. And the question is, typically what we do. 00:36:07.000 --> 00:36:17.000 You establish background in area not impacted by Tca, so which is near that area which is with similar. 00:36:17.000 --> 00:36:37.000 Ethology, similar structure, and so on, and minorology. And then you try to compare the difference, and then you overlap that kind of features for that area which is, we call it, unimpacted versus the other impacted area. 00:36:37.000 --> 00:36:46.000 So that question. If you have done that, and what candle background features that you establish in order to establish the electromagnetic model? 00:36:46.000 --> 00:36:54.000 I realised that you relied on some kind of wealth that they are dear to his service, destruction that would be good to look at an impacted area. 00:36:54.000 --> 00:37:05.000 On similar technology and structure and try to compare it versus when you have, you know, the Tca contamination. 00:37:05.000 --> 00:37:14.000 Yeah. The a, yeah, we weren't identifying whether Tce was present or not. 00:37:14.000 --> 00:37:27.000 We were just trying to identify the paleo channels that continued from on site to off-site, as it would be the bounding channel that the groundwater be flowing at. 00:37:27.000 --> 00:37:33.000 I think I know what you're getting at with. You can use an Am survey for like mineral exploration. 00:37:33.000 --> 00:37:46.000 For example, and and there you're just looking for contrasting differences and and not necessarily like a before and after, like a background. 00:37:46.000 --> 00:37:51.000 And then post cause we're not. We're not changing anything. 00:37:51.000 --> 00:38:01.000 We're not doing anything different. And we wanted to complete the survey all at once, and I will mention this whole survey was done in an hour and 50 min, and which is awesome. 00:38:01.000 --> 00:38:05.000 I know there's a lot of free time and post-processing time. 00:38:05.000 --> 00:38:05.000 Excuse me, or to actually collect the data in less than 2 h. 00:38:05.000 --> 00:38:14.000 It's pretty incredible. Does that answer your question? Yeah, somehow. 00:38:14.000 --> 00:38:23.000 But okay, anyway, that's all. Could have discussion here. Do you have yeah, I was going to say, Gee, fiscal mapping, we're not mapping the Tc directly. 00:38:23.000 --> 00:38:27.000 We're just mapping the aquifer, and that happens with a lot of our targets. 00:38:27.000 --> 00:38:31.000 We're not trying to identify the target. But just the paleo channels. 00:38:31.000 --> 00:38:35.000 Or even meryl exploration. We don't actually look for gold. 00:38:35.000 --> 00:38:47.000 We look for the structures that will host the gold. So, as Colby said, as long as we're flying in areas where we don't think it's there and across areas, we can see that contrast. 00:38:47.000 --> 00:38:48.000 Cool. Okay. Thank you. All right. I see a question in the back. 00:38:48.000 --> 00:38:57.000 Jim Cummings. I can reinforce a couple of the points, and it's different than your electromagnetic. 00:38:57.000 --> 00:39:03.000 The first is, you're to be complemented for finding the Paleo channel, we see too many sites where they are depicting the plumes as blobs, and are not really attacking the plume cores. 00:39:03.000 --> 00:39:15.000 Some wonderful Canadian works suggest that 80% of the mass in a particular plume is likely to be in 10 or 20% of the cross-section area. 00:39:15.000 --> 00:39:20.000 So again, we'd like to see people doing more of this delineation of the plume course. 00:39:20.000 --> 00:39:24.000 The other thing that you to be committed for is your recirculation, because it? 00:39:24.000 --> 00:39:28.000 You know the difficulty of, in fact, delivering reagents. 00:39:28.000 --> 00:39:34.000 So we'd like to see more of this use of recirculation for Institute of Chemical Oxidation. 00:39:34.000 --> 00:39:35.000 But the question I wanted to pose is that the people who have tried to do recirculation? 00:39:35.000 --> 00:39:51.000 It's very easy to say injection and extraction, and varying those, but we're seeing some folks have some difficulty changing a well from one configuration to the other. 00:39:51.000 --> 00:39:55.000 Especially in injection. Sometimes it's more difficult if you start out with a well doing injection. 00:39:55.000 --> 00:40:02.000 To then try to extract from it because of the way it propagates the fines out away from the wellb. 00:40:02.000 --> 00:40:03.000 Did you have any problems in switching your wells in your recirculation mode? 00:40:03.000 --> 00:40:10.000 And if you did have any problems how did you overcome them? 00:40:10.000 --> 00:40:19.000 Okay, so your injection extraction question, we have. 00:40:19.000 --> 00:40:19.000 So some of our wells are monitoring wells. 00:40:19.000 --> 00:40:26.000 We will not inject on. Those we will only extract. 00:40:26.000 --> 00:40:33.000 All the other wells or treatment wells, and will do both at different times, depending on if they're needed. 00:40:33.000 --> 00:40:54.000 For that reason. So there has been some some problems with injection Wells, where you'll have some of the sodium permanganate that precipitates near the screen, and a lot of times just you can develop them. 00:40:54.000 --> 00:40:58.000 And we've been able to extract on them again. 00:40:58.000 --> 00:41:04.000 I think the majority of our issues were the depth of the saturated zone. 00:41:04.000 --> 00:41:14.000 So most of our site is 8 to 12 feet, but there are some up into the 2025 feet saturated zone. 00:41:14.000 --> 00:41:20.000 Our 6 inches to a foot, saturated, and we can't extract from those that have a low volume of water. 00:41:20.000 --> 00:41:37.000 We can only inject, but then, when you inject you get more of that, you get a little bit of mounting, and then you get precipitation of the sodium per mangana kind of creating a shell around the the well. 00:41:37.000 --> 00:41:46.000 But again we can. We can redevelop those to get that communication again. 00:41:46.000 --> 00:41:58.000 Is that? Answer your question, and what was your first part the eighty-twenty 28 I was complimenting you on the fact that you were, in fact, able to delineate your paleo channels. 00:41:58.000 --> 00:42:06.000 We have too many sites where the conceptual side models that are presented by the consultants show a rather undifferentiated blog, and some wonderful work. 00:42:06.000 --> 00:42:21.000 For some Canadian folks 5 or 10 years ago, that hasn't been implemented as well as we think it should, is that the their rule, based on a study of a number of sites, was it 80% of the mass in a particular plume? 00:42:21.000 --> 00:42:27.000 It's likely to be in 10 or 20% of the cross sectional area using a mass flux kind of a characterization. 00:42:27.000 --> 00:42:32.000 And I would surmise that the picture you showed of your plume cores. 00:42:32.000 --> 00:42:38.000 It may have even been 90 to 90, 10. Right? Yeah, yeah, I would agree with that. 00:42:38.000 --> 00:42:41.000 And that's why we want to locate these paleo channels. 00:42:41.000 --> 00:42:52.000 Because if we drill l literally 20 feet to the side we could miss it, or it could be 15 parts per 1 billion. 00:42:52.000 --> 00:42:57.000 And then then be non-detect 15 feet away. 00:42:57.000 --> 00:43:04.000 So, yeah, the paleo channels and hitting that centerline is crucial. 00:43:04.000 --> 00:43:15.000 In this case, and and then I think once we'd found it, we would get more funding to hone in on. 00:43:15.000 --> 00:43:27.000 How wide is this now? So now we know how much distance it traveled down, and we can start to really constrain and and actually encapsulate this plume and have a good look. 00:43:27.000 --> 00:43:32.000 Thorough understanding. 00:43:32.000 --> 00:43:36.000 All right. Thank you. I think we're going to wrap up the Q. 00:43:35.000 --> 00:43:45.000 Wait. I see one more portion. Sure. 00:43:45.000 --> 00:43:50.000 Thank you for your presentation, Erica, to Filipa from Papadopoulos and associates. 00:43:50.000 --> 00:43:52.000 I have a question about the density of like urban structures that you can apply this type of method to. 00:43:52.000 --> 00:44:02.000 So this area is pretty sparsely there. It appears to be. 00:44:02.000 --> 00:44:08.000 There's no structures. You know how how densely populated but of an urban or suburban area. 00:44:08.000 --> 00:44:16.000 Could you use this geophysical technique? 00:44:16.000 --> 00:44:22.000 So this was flown again, and you can see we have tried to avoid all the population. 00:44:22.000 --> 00:44:27.000 We're restricted to the fact that we can't fly over buildings, anything. 00:44:27.000 --> 00:44:33.000 So some of the earlier examples that were under neighborhoods, we wouldn't be able to fly over as well. 00:44:33.000 --> 00:44:52.000 Power lines can interfere with our system a bit. So there is that consideration. And even things in here in California. If the farmers are out in the fields, we're not allowed to fly over. So we'd have to kind of take a look at an area to determine whether it's worthwhile to fly. 00:44:52.000 --> 00:44:56.000 I just wanna make a quick comment from the first talk, and then Colin, and mention that his client had lost faith in the geophysics. 00:44:56.000 --> 00:45:01.000 There a bit which brought a bit of a tear to my eye. 00:45:01.000 --> 00:45:07.000 But the solution was just understanding the method and how it applies to your target. 00:45:07.000 --> 00:45:09.000 So I think it's important when you collect your physical data that you work with your contractor afterwards. 00:45:09.000 --> 00:45:17.000 If it didn't give you the results you expected, because they might be able to help. 00:45:17.000 --> 00:45:23.000 You understand the local conditions, or why it didn't work, or why it did work. 00:45:23.000 --> 00:45:27.000 So I think that's a very important loop to close.