WEBVTT 00:00:00.000 --> 00:00:00.000 And with that, it is my pleasure to welcome you to today's internet seminar. 00:00:00.000 --> 00:00:00.000 Our topic today will be characterization approaches for various types of NAPPLS. We are going to be joined once again by Dr. Eva Davis from EPA's Office of Research and Development. 00:00:00.000 --> 00:00:00.000 She's joining us over the next few weeks for a series of webinars. Today is the second one in that series. 00:00:00.000 --> 00:00:00.000 If you were lucky enough to catch the first part where we talked about migration of napples in the subsurface. 00:00:00.000 --> 00:00:00.000 Today, we're moving on and looking at characterization approaches for those napples. 00:00:00.000 --> 00:00:00.000 I'll be providing some links in the meeting chats for today if you'd like to join her on the two future sessions that we have scheduled 00:00:00.000 --> 00:00:00.000 In early January 25. 00:00:00.000 --> 00:00:00.000 For today's broadcast, I'll be serving as a technical moderator joining you from EPA's Technology Innovation and Field Services Division. 00:00:00.000 --> 00:00:00.000 My job as a moderator is to make sure that everyone understands how to participate in the broadcast and then also represent you vocally to our presenter. 00:00:00.000 --> 00:00:00.000 So we have a unique seminar homepage that was created for today's broadcast. That URL is shown in red at the top of the slide. We also have a QR code available in the lower right for those who prefer to scan. 00:00:00.000 --> 00:00:00.000 That website is the same one that you used when registering. It's the same one we sent you in your confirmation reminder emails. It's essentially the same place you went when checking in for today's session, and it will be active from today forward. So you're welcome to bookmark it and keep it available. 00:00:00.000 --> 00:00:00.000 Because on that website, if you scroll up and down or use those plus and minus icons to collapse and expand sections. 00:00:00.000 --> 00:00:00.000 You'll find a whole slew of information, including info about our presenter, links to download her presentation materials, as well as related resources and publications on today's topic. 00:00:00.000 --> 00:00:00.000 I will make a note that the presentation materials were updated early this morning. So if you happen to download a copy of the slides yesterday, please head back on over to the seminar homepage 00:00:00.000 --> 00:00:00.000 And you'll be able to access the latest version of the slides that we'll be walking through today. 00:00:00.000 --> 00:00:00.000 Now, we'll be hosting today's broadcast live through Zoom webinar. You'll be able to join us using the free Zoom application or through a browser of your choice. 00:00:00.000 --> 00:00:00.000 If you have any technical difficulties joining through Zoom when you check in on Cluwen, you'll be presented with a series of options. The last option you'll see 00:00:00.000 --> 00:00:00.000 is an option to download the slides from the seminar homepage and simply follow along by phone. 00:00:00.000 --> 00:00:00.000 But I encourage you to let me know if you're having issues so we can try to troubleshoot and get you on board for the fully interactive delivery here in Zoom. 00:00:00.000 --> 00:00:00.000 Audio will be available online through Zoom using your device's speakers or headsets or through an optional call-in line available through Zoom. 00:00:00.000 --> 00:00:00.000 Remember, all participants have been muted. If you need to modify your audio connections in Zoom, look in the lower left for an audio settings or join audio button. 00:00:00.000 --> 00:00:00.000 You can use that to adjust the sound and devices being used. 00:00:00.000 --> 00:00:00.000 If you have any continued online audio issues, I encourage you to disconnect from a VPN if that's possible, but if not. 00:00:00.000 --> 00:00:00.000 You can use the Q&A to report the issue to me and I'll work with you to troubleshoot that issue and get you connected by phones if we need to. 00:00:00.000 --> 00:00:00.000 Although we have disabled the meeting chat for today, so if you try to click on the chat button, you'll see a message that it's been disabled. I may periodically send out hyperlinks or references to you in the chat. 00:00:00.000 --> 00:00:00.000 However, you as a member of the audience can use the Q&A button at the bottom of your screen to privately submit comments or questions or report technical difficulties. 00:00:00.000 --> 00:00:00.000 You can also use that to request any additional files or resources. 00:00:00.000 --> 00:00:00.000 That Q&A window will be available all throughout the entire session. 00:00:00.000 --> 00:00:00.000 I encourage you to click it and open up the Q&A window and sort of find a place where it situates and works comfortably for you on your screen. 00:00:00.000 --> 00:00:00.000 We'll take questions later in our broadcast and I'll start reading them out loud to our presenter on your behalf, but there's no need to wait for that designated Q&A break. 00:00:00.000 --> 00:00:00.000 You can start sending your questions in whenever they occur to you. If possible, include a slide number or reference to help our speaker get oriented and head back to the materials that you might be asking about. 00:00:00.000 --> 00:00:00.000 We do also have live closed captioning available in our session today. 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So your audio controls typically will appear in the lower left with the main portion of your screen occupied by our presentation content. 00:00:00.000 --> 00:00:00.000 Speaker information will appear off to the side, but you have some controls in the upper right under a view or view options menu you may see in the middle part of your screen, which will allow you to change the size, scale, and focus of content. 00:00:00.000 --> 00:00:00.000 The CC or transcript button at the bottom center of your screen will allow you to enable live closed captions 00:00:00.000 --> 00:00:00.000 And then that all important Q&A button can be used 00:00:00.000 --> 00:00:00.000 to privately submit your questions, comments, and report technical issues. There is a raise hand feature, but we'll only be doing the raise hand question or vocal question request if we have sufficient time. 00:00:00.000 --> 00:00:00.000 So I do encourage the audience, don't use the raise hand feature unless they come on the line and tell you that we have time to use those. I encourage you to submit your questions in writing 00:00:00.000 --> 00:00:00.000 We can tend to get through a lot more of those 00:00:00.000 --> 00:00:00.000 before we have time for verbal one. 00:00:00.000 --> 00:00:00.000 please use the written format through Q&A. And if we have time for verbal ones, I'll let you know when it's time to raise your 00:00:00.000 --> 00:00:00.000 Okay, with that very brief overview of the tool that we'll be using. 00:00:00.000 --> 00:00:08.000 and how you can participate in our broadcast today. It is my pleasure to introduce you to our speakers. So I recognize some of you may not have been here yesterday for the first talk. 00:00:08.000 --> 00:00:20.000 that Dr. Davis gave us. So if you were not here, I'll just remind you that we are being joined by the wonderful Dr. Ava Davis from EPA's Office of Research and Development. She's been here at EPA 00:00:20.000 --> 00:00:29.000 Since 1990 after she completed a degree in agricultural engineering with a specialization in groundwater contamination at Colorado State University. 00:00:29.000 --> 00:00:36.000 She's a hydrologist in ORD, and her research has included the effects of temperature on the physical properties of organic contaminants 00:00:36.000 --> 00:00:40.000 Thermal degradation of contaminants, and steam injection into fractured rock. 00:00:40.000 --> 00:00:46.000 She's given technical support to numerous Superfund sites and other contaminated sites for thermal remediation, including site characterization. 00:00:46.000 --> 00:00:56.000 evaluating remedial technologies, setting remedial goals, monitoring the implementation of these technologies. And she's also authored an EPA groundwater issue paper on thermal remediation. 00:00:56.000 --> 00:01:02.000 So at this time, I'll go ahead and invite Dr. Davis to come off of mute and to take over sharing her screen. 00:01:02.000 --> 00:01:11.000 Those of you who are joining me online, you are welcome to give a virtual round of applause by typing a quick message to Dr. Davis in the Q&A. 00:01:11.000 --> 00:01:14.000 And then again, Dr. Davis, I see you're off mute. 00:01:14.000 --> 00:01:25.000 So feel free to turn on that screen share and I'll let you know when we can see your slides. 00:01:25.000 --> 00:01:31.000 Okay, your slides are here. If you hide that small floater in the bottom middle of the presentation view 00:01:31.000 --> 00:01:37.000 Dr. Davis, if you want to say hello, I'll confirm we've got good audio and you can carry on with the presentation. 00:01:37.000 --> 00:01:43.000 Good morning or good afternoon, wherever your location may be. 00:01:43.000 --> 00:01:46.000 All right, everything sounds great. Please carry on. 00:01:46.000 --> 00:02:02.000 Okay, thank you for joining today and for welcome back those who were here yesterday. As I said yesterday, I'm talking mostly from my own experience of 34 years of doing technical support. 00:02:02.000 --> 00:02:06.000 and research for Superfund sites. 00:02:06.000 --> 00:02:16.000 I will occasionally bring in some information from others research. I normally point that out when I'm talking about someone else's work. 00:02:16.000 --> 00:02:20.000 Most of it is from my own experience. 00:02:20.000 --> 00:02:29.000 And yesterday I talked about the types of napples that I've encountered while doing technical support. 00:02:29.000 --> 00:02:37.000 and their properties and how they migrate through the subsurface as a lead into then to 00:02:37.000 --> 00:02:41.000 today to talking about characterization of napples. 00:02:41.000 --> 00:02:44.000 And then there's 00:02:44.000 --> 00:02:50.000 to future seminars, what, January 7th and 8th, I believe, are the dates 00:02:50.000 --> 00:02:54.000 We'll talk about what you do about those 00:02:54.000 --> 00:02:58.000 napples once you've located them and you've located them 00:02:58.000 --> 00:03:04.000 in order to remediate the site. 00:03:04.000 --> 00:03:08.000 And so to move in today into today's presentation. 00:03:08.000 --> 00:03:12.000 Characterization really is a very vital 00:03:12.000 --> 00:03:23.000 part of the remediation process. You have to know where the source is in order to remediate it. 00:03:23.000 --> 00:03:27.000 normally when you first go on to a side deer, but a site is first uh 00:03:27.000 --> 00:03:33.000 being investigated as pre-rod, and that may be in a general 00:03:33.000 --> 00:03:38.000 investigation of the site characteristics and the contaminants there. 00:03:38.000 --> 00:03:48.000 Normally we get into a more in-depth delineation of the extent of the NAPL in a pre-designed investigation. 00:03:48.000 --> 00:03:52.000 And what we're looking to 00:03:52.000 --> 00:04:01.000 find out in that characterization is where the contaminant source is, as well as get a feel for what is the mass of the 00:04:01.000 --> 00:04:03.000 Apple. 00:04:03.000 --> 00:04:05.000 in that. 00:04:05.000 --> 00:04:10.000 area and now estimating the mass of NAPL is 00:04:10.000 --> 00:04:20.000 more of an art than a science, it seems like. I've seen estimates that were way high and way low than when compared to 00:04:20.000 --> 00:04:25.000 the mass that was recovered during a thermal remediation. 00:04:25.000 --> 00:04:30.000 But we do our best to try to estimate the mass that's there. 00:04:30.000 --> 00:04:37.000 You also have to know the geologic setting, the geology, the soils type, geology, stratigraphy. 00:04:37.000 --> 00:04:41.000 As well as the hydrogeology, present historical water table 00:04:41.000 --> 00:04:46.000 elevations, groundwater flow and direction and velocity. 00:04:46.000 --> 00:04:52.000 in order to be able to choose the best remedial technology for the site. 00:04:52.000 --> 00:04:57.000 And one of the things to point out right away 00:04:57.000 --> 00:05:03.000 is that a characterization approach and the tools you use for it 00:05:03.000 --> 00:05:09.000 may not be ideal for all sites. You have to adjust your 00:05:09.000 --> 00:05:12.000 the tools you're using and the approach you take 00:05:12.000 --> 00:05:18.000 to work for the particular site where you are. 00:05:18.000 --> 00:05:26.000 I always recommend the triad approach for characterization. It's not a new 00:05:26.000 --> 00:05:34.000 idea. I think it's been around since the 1990s, but there seems to be some reluctance with using it. 00:05:34.000 --> 00:05:37.000 I think it's by far the most efficient way 00:05:37.000 --> 00:05:47.000 of characterizing a site in detail, particularly when you're looking for an apple and to delineate the napple. 00:05:47.000 --> 00:05:55.000 To me, the triad approach means that you respond in the field to the data that's being collected. 00:05:55.000 --> 00:05:58.000 to guide future data collection. 00:05:58.000 --> 00:06:06.000 And in order for that to work, then you've got to have real-time data. And so we'll talk about how to get that real-time data and how that data 00:06:06.000 --> 00:06:08.000 is used to use is used 00:06:08.000 --> 00:06:13.000 to guide the future data collection. 00:06:13.000 --> 00:06:18.000 So you've got systematic planning to begin with 00:06:18.000 --> 00:06:23.000 Use what you know about the site to use the site to 00:06:23.000 --> 00:06:27.000 plan your field work to get the data that you need. 00:06:27.000 --> 00:06:32.000 You use real-time measurement technologies then to get that data. 00:06:32.000 --> 00:06:38.000 And a dynamic work strategy where you evaluate the data as it's coming in. 00:06:38.000 --> 00:06:46.000 The field crew is probably talking to the rest of the team back in the office on a regular basis to determine 00:06:46.000 --> 00:06:50.000 where to go next to collect additional data. 00:06:50.000 --> 00:06:55.000 Until they have filled all the data gaps. 00:06:55.000 --> 00:06:59.000 systematic planning. How do you start? 00:06:59.000 --> 00:07:06.000 with this. Well, you start with what you do already know about the site. If you've got reason to believe they're 00:07:06.000 --> 00:07:19.000 there's contamination there, you know something already. You can look at what has been done at the site and where it was done. If it's a manufacturing facility, where was the main processing area? 00:07:19.000 --> 00:07:23.000 Where were the different unit processes located? 00:07:23.000 --> 00:07:27.000 We're waste ponds. 00:07:27.000 --> 00:07:31.000 facilities had waste ponds where they had 00:07:31.000 --> 00:07:42.000 where the waste were pumped into maybe a clay line basin and maybe there's no lining in it. Above ground and below ground storage tanks 00:07:42.000 --> 00:07:45.000 are always a source of a source of 00:07:45.000 --> 00:07:48.000 a potential source of contamination. 00:07:48.000 --> 00:07:54.000 So you need to know what chemicals were used on site and where they were stored. 00:07:54.000 --> 00:08:00.000 And a lot of these manufacturing sites, you might also have fuels that were stored there. 00:08:00.000 --> 00:08:12.000 You look at the historical data and don't throw all of that out. Now, there may be some quality issues with some of it that need to be considered. 00:08:12.000 --> 00:08:21.000 And it is possible some things could have changed if that data is 20 years old. 00:08:21.000 --> 00:08:27.000 at the site could have changed. So you need to evaluate that data and determine 00:08:27.000 --> 00:08:36.000 what is still good that you can use as a basis then to move forward with getting the rest of the data that's needed. 00:08:36.000 --> 00:08:41.000 And as I say, site usage may have changed over time. 00:08:41.000 --> 00:08:48.000 And so you have to, aerial photos may be useful in figuring out changes that have happened 00:08:48.000 --> 00:08:53.000 over time at some large facilities, I know they've talked to 00:08:53.000 --> 00:09:05.000 former employees or current employees part of the time to find where things have been done, what the disposal practices were, any spills that might have occurred. 00:09:05.000 --> 00:09:16.000 And as part of that planning is in figuring out how you're going to respond to the data that is obtained as you move forward with the 00:09:16.000 --> 00:09:18.000 characterization. 00:09:18.000 --> 00:09:21.000 The dynamics work strategy 00:09:21.000 --> 00:09:26.000 really is dependent upon having real-time data. 00:09:26.000 --> 00:09:36.000 common things that are used for that when you're looking for volatile compounds, so chlorinated solvents in particular. 00:09:36.000 --> 00:09:38.000 membrane interface probe. 00:09:38.000 --> 00:09:44.000 or if you're looking for if you're looking for 00:09:44.000 --> 00:09:53.000 Napples such as coal tar or creosote, something with polynuclear aromatic hydrocarbons that will fluoresce. 00:09:53.000 --> 00:10:01.000 a laser-induced fluorescence is a very useful tool for detecting those contaminants. 00:10:01.000 --> 00:10:03.000 But these are screening. 00:10:03.000 --> 00:10:09.000 tools and the results that you get 00:10:09.000 --> 00:10:14.000 from either of these instruments really needs to be confirmed with some soil samples. 00:10:14.000 --> 00:10:19.000 So soil borings are also needed then to confirm at least a presented 00:10:19.000 --> 00:10:27.000 a percentage of the screening results. And then once you've confirmed that you're, when you start 00:10:27.000 --> 00:10:31.000 in an area where you know or highly suspect 00:10:31.000 --> 00:10:34.000 that there is an apple contamination 00:10:34.000 --> 00:10:38.000 to confirm that the tool can detect 00:10:38.000 --> 00:10:41.000 the NAPPL in that setting. 00:10:41.000 --> 00:10:45.000 And then once you get the response. 00:10:45.000 --> 00:10:47.000 that it shows that 00:10:47.000 --> 00:10:50.000 It is detecting an apple. 00:10:50.000 --> 00:10:57.000 Then you confirm that with the soil samples and then you step out in all directions laterally 00:10:57.000 --> 00:11:00.000 until you have determined the extent of the NAPPL. 00:11:00.000 --> 00:11:10.000 Distance between borings is generally going to be in the range of 20 to 50 feet, depending upon 00:11:10.000 --> 00:11:11.000 the overall size of the site 00:11:11.000 --> 00:11:15.000 and your objectives at that point, you know. 00:11:15.000 --> 00:11:20.000 if you're in a pre-rod characterization situation. 00:11:20.000 --> 00:11:21.000 You may have wider spacing. 00:11:21.000 --> 00:11:27.000 when you're really trying to finally delineate the NAPPL, you're going to use a closer spacing. 00:11:27.000 --> 00:11:34.000 And you generally want to continue this stepping out from the NAPL source until you get 00:11:34.000 --> 00:11:39.000 clean borings and that clean, of course, is in quotes because 00:11:39.000 --> 00:11:48.000 You're not looking for contaminant free, but you're looking for no signs of NACL presence. 00:11:48.000 --> 00:11:51.000 out in that area. 00:11:51.000 --> 00:11:54.000 When looking for when looking for 00:11:54.000 --> 00:11:58.000 an apple source. We generally use the lines of evidence approach 00:11:58.000 --> 00:12:01.000 Now, as we're going to be talking about, there are some 00:12:01.000 --> 00:12:05.000 some types of contaminants and apples that are 00:12:05.000 --> 00:12:10.000 very visible in most types of soil situations and if you 00:12:10.000 --> 00:12:13.000 can see the NAPL. 00:12:13.000 --> 00:12:18.000 in a soil core, then that's the line of evidence that you need it you know 00:12:18.000 --> 00:12:23.000 confirm there's an apple present at that location. Most 00:12:23.000 --> 00:12:27.000 Napples don't show themselves that readily. 00:12:27.000 --> 00:12:35.000 So we start, you know, our first line of evidence is response we get from our screening tools, the MIP and the LIF. 00:12:35.000 --> 00:12:39.000 And then you look at the uh 00:12:39.000 --> 00:12:42.000 the soil cores uh and 00:12:42.000 --> 00:12:45.000 Those cores are normally screened then 00:12:45.000 --> 00:12:56.000 with a PID or FID, that can be very useful in determining if volatile contaminants are present. The PID picks up 00:12:56.000 --> 00:13:02.000 a lot of the chlorinated solvents, FID is more particular for 00:13:02.000 --> 00:13:09.000 petroleum hydrocarbons, the volatile ones. Odor can be a real easy way to 00:13:09.000 --> 00:13:11.000 to note that the 00:13:11.000 --> 00:13:20.000 the potential presence of NAPL, different types of dyes, oil red dyes, there's Sudan dyes, have been used. They will preferentially 00:13:20.000 --> 00:13:29.000 partition into NAPLS and the red color shows the presence of the napples. 00:13:29.000 --> 00:13:34.000 and analytical samples should always be a part of that as well. 00:13:34.000 --> 00:13:37.000 And as far as I'm concerned you really 00:13:37.000 --> 00:13:43.000 can't take too many analytical samples, particularly when it comes time then to try to estimate the mass. 00:13:43.000 --> 00:13:52.000 that is there. Ancillary indications of contamination and possible presence of NAPL includes the groundwater data. 00:13:52.000 --> 00:13:57.000 And we'll talk about that some more. I'm not talking a whole lot about 00:13:57.000 --> 00:14:03.000 The vapor data, we'll mention that some. But then it 00:14:03.000 --> 00:14:10.000 If you see oil sheen either on top of the water or within the soils, that's another pretty darn good indication. 00:14:10.000 --> 00:14:15.000 that there is an Apple very close by. 00:14:15.000 --> 00:14:24.000 So the real-time data of a MIP, screening for indications of VOCs. 00:14:24.000 --> 00:14:30.000 These are good for the chlorinated compounds and for volatile fuels. 00:14:30.000 --> 00:14:33.000 the refined fuels end. 00:14:33.000 --> 00:14:38.000 Typically, the MIP will have three different sensors on it. 00:14:38.000 --> 00:14:49.000 The PID being most sensitive to like chlorinated solvents, FID for hydrocarbons, XSD, 00:14:49.000 --> 00:14:54.000 detector detects halogens. 00:14:54.000 --> 00:15:02.000 In the example that I'm showing here, you can see that all three of the sensors really gave a pretty strong response. 00:15:02.000 --> 00:15:07.000 And this was in a response to TCE in the subsurface. 00:15:07.000 --> 00:15:13.000 The XSD was most sensitive to that tce 00:15:13.000 --> 00:15:19.000 PID showed good sensitivity as well. The FID a little less sensitive. 00:15:19.000 --> 00:15:23.000 to it. 00:15:23.000 --> 00:15:30.000 And something I will say repeatedly that, and I can't say too many times is that 00:15:30.000 --> 00:15:41.000 The MIP data is screening data that indicates the presence of VOCs, but not necessarily the concentration of VOCs in the soil or in the groundwater. 00:15:41.000 --> 00:15:46.000 And thus the MIP data is not reliable 00:15:46.000 --> 00:15:49.000 for estimating the mass in the subsurface. 00:15:49.000 --> 00:15:57.000 But it is a good indicator of the presence of some level of contamination. 00:15:57.000 --> 00:16:03.000 For estimating NAPA mass, what you really need is that soil concentration data. 00:16:03.000 --> 00:16:10.000 And this graph is from others research on the development of the MIP tool. 00:16:10.000 --> 00:16:12.000 that shows the 00:16:12.000 --> 00:16:17.000 the MIP response along the horizontal axis there 00:16:17.000 --> 00:16:28.000 And the 8260 result, I do believe this was TCE that they were analyzing for there. And you can see there is some 00:16:28.000 --> 00:16:32.000 linearity in the response. 00:16:32.000 --> 00:16:34.000 But there's also some 00:16:34.000 --> 00:16:41.000 Some of the readings are very far off from what was then found in the soil samples. 00:16:41.000 --> 00:16:43.000 And so 00:16:43.000 --> 00:16:49.000 use myth data as an indication of the presence of the contaminants 00:16:49.000 --> 00:16:55.000 but not a strong indicator of the amount of mass at that location. 00:16:55.000 --> 00:16:58.000 Another example of that, this is from 00:16:58.000 --> 00:17:02.000 This data is from 00:17:02.000 --> 00:17:08.000 the analysis of chlorobenzene in soil 00:17:08.000 --> 00:17:12.000 that concentration, again, from the 8260 analysis 00:17:12.000 --> 00:17:17.000 versus a headspace PID reading from that soil core 00:17:17.000 --> 00:17:22.000 And you can see that a lot of the headspace PID readings were quite low. 00:17:22.000 --> 00:17:32.000 Even when the contamination was, even when there was very significant concentrations of chlorobenzene within the 00:17:32.000 --> 00:17:37.000 the soil. Again, the PID of a 00:17:37.000 --> 00:17:39.000 Soil core is used to soil 00:17:39.000 --> 00:17:42.000 screen this 00:17:42.000 --> 00:17:47.000 core to try to determine where the highest concentrations likely are 00:17:47.000 --> 00:17:52.000 to be able to then get a sample from that location. 00:17:52.000 --> 00:17:55.000 And… 00:17:55.000 --> 00:18:04.000 the analytical result then is what you need in order to estimate mass. 00:18:04.000 --> 00:18:13.000 When you're looking for contaminants such as creosote or coal tar at wood treater sites or MGP sites. 00:18:13.000 --> 00:18:18.000 These contaminants are not volatile enough really to be picked up by 00:18:18.000 --> 00:18:27.000 a membrane interface probe and they don't respond the same to those detectors. So what is commonly used is laser induced fluorescence. 00:18:27.000 --> 00:18:29.000 These PAHs. 00:18:29.000 --> 00:18:36.000 polynuclear aromatic hydrocarbons that comprise a very large percentage of these 00:18:36.000 --> 00:18:39.000 of these napples uh we'll 00:18:39.000 --> 00:18:48.000 when excited by a laser, they will give back part of that excitation that they've 00:18:48.000 --> 00:18:51.000 And that's why they say they fluoresce. 00:18:51.000 --> 00:18:55.000 And there are different lasers available these days for 00:18:55.000 --> 00:19:02.000 petroleum hydrocarbons, more like the refined hydrocarbons fuels 00:19:02.000 --> 00:19:11.000 And a separate one then for the heavier PAHs in creosote or coal tar. 00:19:11.000 --> 00:19:14.000 Again, these 00:19:14.000 --> 00:19:21.000 instruments are based on a cone penetrometer for 00:19:21.000 --> 00:19:28.000 for applying them in the field. And again, it's a situation that this is a screening tool that 00:19:28.000 --> 00:19:32.000 indicates the presence of contaminants. 00:19:32.000 --> 00:19:39.000 But it's not linearly correlated to the concentration of the contaminants that are present. 00:19:39.000 --> 00:19:47.000 And with the LIF false positives can really 00:19:47.000 --> 00:19:49.000 be difficult to be difficult 00:19:49.000 --> 00:19:53.000 to interpret and so 00:19:53.000 --> 00:20:02.000 Again, I can't overestimate or overemphasize the importance of validating the response with soil cores. 00:20:02.000 --> 00:20:12.000 something that has hit my desk very recently was asked to help evaluate some LIF data 00:20:12.000 --> 00:20:14.000 from a creosote site, a Superfund site. 00:20:14.000 --> 00:20:17.000 And you can see the 00:20:17.000 --> 00:20:23.000 percent fluorescence response from the LIF that's shown in red on these. 00:20:23.000 --> 00:20:26.000 And this was i find 00:20:26.000 --> 00:20:36.000 to be rather surprising that they were the green bars that you have at various steps on these 00:20:36.000 --> 00:20:38.000 on these readouts. 00:20:38.000 --> 00:20:45.000 is the pyrene concentration in micrograms per kilogram. 00:20:45.000 --> 00:20:52.000 That to me kind of indicates maybe a problem with understanding just what is being measured. 00:20:52.000 --> 00:20:57.000 by the LIF in a creosote and coal tar 00:20:57.000 --> 00:21:03.000 There are a very large number of different PAHs 00:21:03.000 --> 00:21:07.000 that comprise the NAPL. 00:21:07.000 --> 00:21:12.000 And the various PAHs can be present in 00:21:12.000 --> 00:21:16.000 varying concentrations within that NAPL. 00:21:16.000 --> 00:21:19.000 And so to try to 00:21:19.000 --> 00:21:28.000 correlate and pyrene is one of those PAHs that's found in creosote and coal tar. It is one of the 16 00:21:28.000 --> 00:21:33.000 PAHs at EPA considers priority pollutants. 00:21:33.000 --> 00:21:38.000 But to think that there would be a correlation between that 00:21:38.000 --> 00:21:43.000 concentration in the soil and the LIF response i think is 00:21:43.000 --> 00:21:49.000 a lack of understanding of just what is measured by that fluorescence response because that 00:21:49.000 --> 00:21:54.000 fluorescence response that you're seeing from this instrument should be from 00:21:54.000 --> 00:22:00.000 all of the PAHs that are present that fluoresce in that wavelength and 00:22:00.000 --> 00:22:07.000 it should not be correlated in any way to just the concentration of one 00:22:07.000 --> 00:22:10.000 of those PAHs. 00:22:10.000 --> 00:22:15.000 Another instrument that 00:22:15.000 --> 00:22:21.000 trying to extend the use of the LIF to 00:22:21.000 --> 00:22:25.000 chlorinated solvents is called the dye lif 00:22:25.000 --> 00:22:30.000 As I just said, it's used for 00:22:30.000 --> 00:22:33.000 chlorinated solvents, VOCs. 00:22:33.000 --> 00:22:36.000 And the idea here was that, you know, since 00:22:36.000 --> 00:22:44.000 TCE, PCE, these types of chlorinated solvents, since they don't have 00:22:44.000 --> 00:22:50.000 Since the molecules that make up those compounds do not fluoresce. 00:22:50.000 --> 00:22:54.000 The idea was to add a dye 00:22:54.000 --> 00:22:58.000 to the subsurface as your uh 00:22:58.000 --> 00:23:02.000 as you're deploying this probe. 00:23:02.000 --> 00:23:06.000 that would then dissolve 00:23:06.000 --> 00:23:09.000 the solvent if they're present. 00:23:09.000 --> 00:23:12.000 If it is present and 00:23:12.000 --> 00:23:17.000 That dye then would respond to the excitation of the laser 00:23:17.000 --> 00:23:21.000 as it then passes by that same spot. 00:23:21.000 --> 00:23:27.000 allowing you then to detect the presence of chlorinated solvents 00:23:27.000 --> 00:23:30.000 by the LIF. 00:23:30.000 --> 00:23:39.000 And you can see the white boxes shows different waveforms that may be present. 00:23:39.000 --> 00:23:45.000 Here again, you know, there's as with 00:23:45.000 --> 00:23:48.000 the LIF used for 00:23:48.000 --> 00:23:53.000 other PAHs, there can be false positives 00:23:53.000 --> 00:23:59.000 And so they have to look at the waveforms in order to tell 00:23:59.000 --> 00:24:06.000 whether it is something naturally occurring that is causing the fluorescence 00:24:06.000 --> 00:24:12.000 Or if the fluorescence that is then being detected is actually due to a D-napple. 00:24:12.000 --> 00:24:17.000 presence. And again, this is just 00:24:17.000 --> 00:24:22.000 one more line of evidence of NAPL and the response has to be validated against soil cores. 00:24:22.000 --> 00:24:28.000 And in fact, the company that makes this instrument 00:24:28.000 --> 00:24:36.000 prefers to be able to get a soil sample back in their lab before this instrument is actually deployed in the field. 00:24:36.000 --> 00:24:45.000 to ensure that you can get the response that you're looking for with this technology. 00:24:45.000 --> 00:24:53.000 And I have only seen the use of this instrument on one side, a TCE site, and I will say that 00:24:53.000 --> 00:25:00.000 It was not very effective at that site. 00:25:00.000 --> 00:25:08.000 I've heard others say that it was very effective for locating solvents in Apple at other sites, but 00:25:08.000 --> 00:25:15.000 As I said early on, not all tools are equally effective at all. 00:25:15.000 --> 00:25:19.000 at all sites, you have to find what works at your site. 00:25:19.000 --> 00:25:22.000 Oh. 00:25:22.000 --> 00:25:33.000 Just to show you how complicated it can be to interpret the results from a dialif and this is one of the 00:25:33.000 --> 00:25:38.000 No, this is sample data, but this show 00:25:38.000 --> 00:25:41.000 really the type of problem that we were 00:25:41.000 --> 00:25:54.000 having at the one site where I saw this instrument deployed, we were getting very low responses over here on the left hand side of it, the waveforms 00:25:54.000 --> 00:25:57.000 weren't, some of them weren't some 00:25:57.000 --> 00:26:01.000 indicated in Apple, but the response 00:26:01.000 --> 00:26:06.000 you know the percent fluorescence was not very large at all. 00:26:06.000 --> 00:26:10.000 A lot of background noise in terms of 00:26:10.000 --> 00:26:16.000 the injection of the dye and the pressure needed to uh 00:26:16.000 --> 00:26:20.000 to inject that dye. 00:26:20.000 --> 00:26:26.000 And the waveform's just not lining up with 00:26:26.000 --> 00:26:28.000 a strong indication that it was NAPPL. 00:26:28.000 --> 00:26:33.000 that it was detecting. 00:26:33.000 --> 00:26:36.000 Down hold cameras. 00:26:36.000 --> 00:26:38.000 I'm not. 00:26:38.000 --> 00:26:43.000 It seems like they were used more in the past than what I see them being used now. 00:26:43.000 --> 00:26:53.000 in unconsolidated media. Now, what we have here is a picture that came from a GeoViz. It was a downhole camera. 00:26:53.000 --> 00:26:59.000 that was used in boreholes. This was taken at a waste oil site 00:26:59.000 --> 00:27:02.000 in the San Francisco Bay Area. 00:27:02.000 --> 00:27:05.000 And you can see the uh 00:27:05.000 --> 00:27:12.000 little bubbles, air bubbles or these may be 00:27:12.000 --> 00:27:15.000 gases from the degradation of the oil 00:27:15.000 --> 00:27:19.000 There was also solvents. 00:27:19.000 --> 00:27:21.000 within these oils. 00:27:21.000 --> 00:27:27.000 And as well as, and the dark areas then are the waste oil 00:27:27.000 --> 00:27:29.000 that was within the 00:27:29.000 --> 00:27:32.000 the pores and the purple 00:27:32.000 --> 00:27:38.000 blobs or your soil grains. Where I have seen 00:27:38.000 --> 00:27:41.000 a camera 00:27:41.000 --> 00:27:45.000 being most useful is in detecting the 00:27:45.000 --> 00:27:54.000 napples that are darker in color and highly visible in the soil than for the creosote and cold tar type. 00:27:54.000 --> 00:27:57.000 Napples. 00:27:57.000 --> 00:28:01.000 So these screening tools 00:28:01.000 --> 00:28:08.000 are based on a CPT generally or a geoprobes in some cases 00:28:08.000 --> 00:28:12.000 for deploying them. 00:28:12.000 --> 00:28:19.000 into the subsurface, there are generally fast and less costly than obtaining soil cores. 00:28:19.000 --> 00:28:27.000 And they get that real-time data that can make these tools very useful when you're doing a 00:28:27.000 --> 00:28:31.000 a triad approach for your characterization. 00:28:31.000 --> 00:28:36.000 they give essentially continuous vertical readings 00:28:36.000 --> 00:28:40.000 And then you have to decide on your 00:28:40.000 --> 00:28:46.000 on the lateral spreading of the readings, but they do give uh 00:28:46.000 --> 00:28:49.000 essentially continuous vertical readings. 00:28:49.000 --> 00:28:55.000 But they must be validated by comparison of the response to soil cores. 00:28:55.000 --> 00:28:59.000 And the concentrations do not correlate 00:28:59.000 --> 00:29:03.000 well with the soil concentrations. 00:29:03.000 --> 00:29:09.000 If you've got a site that is tight, a lot of infrastructure on the surface. 00:29:09.000 --> 00:29:13.000 A smaller rig may give you better 00:29:13.000 --> 00:29:16.000 access to 00:29:16.000 --> 00:29:23.000 be able to get into the tight areas to get the data. But the smaller the rig is may also 00:29:23.000 --> 00:29:28.000 limit how deep you can go with that 00:29:28.000 --> 00:29:30.000 at that location. 00:29:30.000 --> 00:29:36.000 These tools will meet refusal in tight soils 00:29:36.000 --> 00:29:39.000 in weathered bedrock 00:29:39.000 --> 00:29:43.000 when it encounters some other kind of subsurface destruction 00:29:43.000 --> 00:29:46.000 You know, an old foundation 00:29:46.000 --> 00:29:49.000 at a site that is now buried over. 00:29:49.000 --> 00:29:58.000 and even thick sand beds can produce enough friction on the sides of these tools to be able to limit 00:29:58.000 --> 00:30:01.000 their penetration depth and or or 00:30:01.000 --> 00:30:03.000 gravel can… 00:30:03.000 --> 00:30:07.000 can really eat up the sides 00:30:07.000 --> 00:30:13.000 these tools as they're as you try to deploy them. 00:30:13.000 --> 00:30:21.000 The tone penetrometers can also be used to obtain these soil cores that I've been encouraging you to use. 00:30:21.000 --> 00:30:28.000 But as I've just been talking about, the limitations of depth. 00:30:28.000 --> 00:30:32.000 that you generally encounter with these 00:30:32.000 --> 00:30:40.000 tools. The maximum depth that I've seen for deploying these types of tools from a CPT 00:30:40.000 --> 00:30:44.000 is generally around 100 feet. 00:30:44.000 --> 00:30:50.000 But many times refusal is hit before that depth. 00:30:50.000 --> 00:30:58.000 maybe in the range of 40 to 60 feet. And someone asked me at the conclusion of yesterday's 00:30:58.000 --> 00:31:04.000 presentation, how deep have I seen NAPL in the subsurface and 00:31:04.000 --> 00:31:10.000 One site I worked on, one creosote site we worked on in California. 00:31:10.000 --> 00:31:16.000 shows NAPPL down to approximately 250 feet below ground surface 00:31:16.000 --> 00:31:26.000 at another jet fuel site, I'll be showing some data from the NAPL extended to 240 feet below ground surface. 00:31:26.000 --> 00:31:30.000 And so in a lot of situations 00:31:30.000 --> 00:31:35.000 any tool that's deployed by a CPT 00:31:35.000 --> 00:31:39.000 may very well not be able to 00:31:39.000 --> 00:31:42.000 get to the total depth 00:31:42.000 --> 00:31:46.000 of which NAPLA has penetrated. 00:31:46.000 --> 00:31:58.000 The soil cores from these CPT are generally small in diameter, one to two inches, which can make it more difficult to detect the presence of the napple within the core. 00:31:58.000 --> 00:32:05.000 is shorter runs, generally two to four feet, that actually makes 00:32:05.000 --> 00:32:12.000 getting soil cores with the CBT, a slower process than using a drill rig. 00:32:12.000 --> 00:32:22.000 And again, as I say, the refusal in tight soils, weathered bedrock, gravel, and on boulders 00:32:22.000 --> 00:32:30.000 Rotosonic rigs are what I have found to be very good for obtaining 00:32:30.000 --> 00:32:32.000 soil cores 00:32:32.000 --> 00:32:41.000 The larger diameter cores are generally four inches in diameter and they're continuous and that larger diameter 00:32:41.000 --> 00:32:46.000 can facilitate observations of NAPL. 00:32:46.000 --> 00:32:48.000 And I know that 00:32:48.000 --> 00:32:54.000 One of the complaints I hear a lot is, you know, roadsonics they produce heat 00:32:54.000 --> 00:32:58.000 But generally an unconsolidated soil is that heat generation is not 00:32:58.000 --> 00:33:05.000 great enough for it to really be an issue. And then two, because you have a larger diameter core 00:33:05.000 --> 00:33:14.000 it doesn't generally affect the center of the soil core as much. And so even VOCs are not 00:33:14.000 --> 00:33:24.000 lost significantly from these cores by any heat that might be generated. Now, if you're going through an old 00:33:24.000 --> 00:33:33.000 foundation, concrete foundation. I guess the sonic will go through it, but in that case, you're probably going to generate some heat. 00:33:33.000 --> 00:33:43.000 These generally can do a 10 foot run, which means it's faster than using the CPT. 00:33:43.000 --> 00:33:45.000 And the… 00:33:45.000 --> 00:33:49.000 Normally, these are 00:33:49.000 --> 00:33:51.000 rigs will use an outer casing around the core barrel. 00:33:51.000 --> 00:33:59.000 which seals off the boring from the formation. And so if you've got 00:33:59.000 --> 00:34:05.000 Dean Apple, or if you're working in the VATO zone with an el apple. 00:34:05.000 --> 00:34:14.000 that casing, that outer casing does not allow the knackle to flow down through the borehole as you're drilling. 00:34:14.000 --> 00:34:18.000 Another way in order to protect lower formations 00:34:18.000 --> 00:34:26.000 from Dean Apple, I've seen them use, you know, drill to the bottom of the low permeability zone 00:34:26.000 --> 00:34:32.000 stopping just a little bit above where they want to protect the lower, more permeable zone. 00:34:32.000 --> 00:34:37.000 and put in a bentonite plug, let that set up, and then go ahead and drill through it. 00:34:37.000 --> 00:34:40.000 sort of telescoping downward. 00:34:40.000 --> 00:34:47.000 And these rigs have a real advantage in that they're not really depth limited. 00:34:47.000 --> 00:34:57.000 get you to that 240 and 250 feet that you need to get to in order to fully delineate the vertical extent of the NAPA. 00:34:57.000 --> 00:35:02.000 Oh, just to… 00:35:02.000 --> 00:35:10.000 show you what it can look like. This is coal tar and creosote site in Washington state. 00:35:10.000 --> 00:35:12.000 And you can see that you can see 00:35:12.000 --> 00:35:18.000 the coal tar and you can't miss it when it's coming out of the 00:35:18.000 --> 00:35:25.000 the side of the trench here is in the picture in the right. And then when that trench reached the groundwater table then you can see 00:35:25.000 --> 00:35:31.000 part of the elm apple from that cold har on top of the water. 00:35:31.000 --> 00:35:39.000 There's all the evidence you need that, yes, there is an apple present. 00:35:39.000 --> 00:35:40.000 However. 00:35:40.000 --> 00:35:45.000 fuels as well as chlorinated solvents are much, much more difficult to 00:35:45.000 --> 00:35:53.000 be able to see in soil cores. This is a sonic core in the picture here from a 00:35:53.000 --> 00:35:55.000 site with jet fuel. 00:35:55.000 --> 00:36:00.000 they screen the cores end with PID or actually FID in this case 00:36:00.000 --> 00:36:10.000 And had a high enough hit that they thought might be indicative of the presence of Apple. 00:36:10.000 --> 00:36:16.000 And so they use the oil red O test, which is the vial that is sitting on top of the core. 00:36:16.000 --> 00:36:23.000 And you can mostly see, well, really you can only see green in that picture. 00:36:23.000 --> 00:36:30.000 But the caption that went along with this photo said that there was a real faint red 00:36:30.000 --> 00:36:34.000 that they could also see in that test. 00:36:34.000 --> 00:36:41.000 that indicated the presence of a small amount of NAPL at that location. 00:36:41.000 --> 00:36:48.000 But really, analytical samples can be a lot more reliable 00:36:48.000 --> 00:36:56.000 Once you have a feel for what kind of concentrations and are indicative of NAPPL. 00:36:56.000 --> 00:36:58.000 So I always encourage 00:36:58.000 --> 00:37:05.000 soil samples every like five to 10 feet along the length of the core. 00:37:05.000 --> 00:37:07.000 Now. 00:37:07.000 --> 00:37:18.000 And I used this picture in yesterday's, both of these pictures yesterday in my presentation on different napples and how they migrate. 00:37:18.000 --> 00:37:20.000 And this is… 00:37:20.000 --> 00:37:25.000 Chlorobenzene and DDT from a DDT manufacturing facility 00:37:25.000 --> 00:37:31.000 You can see the dean apple in the bottom of the beaker there that's dark in color. 00:37:31.000 --> 00:37:39.000 Chlorobenzene is normally a clear liquid, but it picks up impurities as it travels through the soil. 00:37:39.000 --> 00:37:49.000 when they pull this up out of the well, it was very easy to see the napple in the bottom versus the contaminated groundwater above it. 00:37:49.000 --> 00:37:52.000 But in the soil core. 00:37:52.000 --> 00:37:57.000 The NAPA was not visible. And in this soil core 00:37:57.000 --> 00:38:03.000 And there's actually a thin sand zone in between 00:38:03.000 --> 00:38:06.000 more silty 00:38:06.000 --> 00:38:12.000 soils on either side of it here and that's the flutie ribbon that's behind the core 00:38:12.000 --> 00:38:17.000 And the flutie ribbon has a dye in it that uh 00:38:17.000 --> 00:38:21.000 when it encounters one of these chlorinated solvent napples. 00:38:21.000 --> 00:38:27.000 then the colors show up. And you can see that the flutie ribbon is 00:38:27.000 --> 00:38:33.000 indicating the presence of NAPL within that thin sandy zone of this core. 00:38:33.000 --> 00:38:39.000 But that's not something that was visible to the native eye that there was an apple present there. 00:38:39.000 --> 00:38:48.000 But that should be taken as a pretty darn good indication, though, too, of the presence of NAPL at that location. 00:38:48.000 --> 00:38:53.000 So how deep do you go when you're looking for an apple? 00:38:53.000 --> 00:38:58.000 And I'll show you some more data. 00:38:58.000 --> 00:39:02.000 results and characterization of an El Napple site 00:39:02.000 --> 00:39:08.000 Where at the time that the spill occurred, it was a very large spill of jet fuel. And at the time that it occurred. 00:39:08.000 --> 00:39:17.000 the groundwater table was approximately 240 feet below the ground surface and the elm apple made it all the way to that depth. 00:39:17.000 --> 00:39:22.000 But then, and this was in the Phoenix area 00:39:22.000 --> 00:39:35.000 As the population grew and there was less irrigation in the area, the water table started to rise again and it's currently up at about 140 feet below ground surface. 00:39:35.000 --> 00:39:39.000 And that napple that had flowed through the 00:39:39.000 --> 00:39:55.000 all through the lower permeability soils all the way to 240 feet, it did not rise with the water table, but there's a mobile apple trap below some of the 00:39:55.000 --> 00:40:02.000 some of the lower permeability zones. And so just if when you're looking for an apple just 00:40:02.000 --> 00:40:04.000 going to the current water 00:40:04.000 --> 00:40:14.000 may not give you the bottom of where the elm apple is. And I'll show you some more on that in just a minute. 00:40:14.000 --> 00:40:23.000 For a Dean Apple, it can be site specific based on the geology and of course, you know, dependent too on how much was spilled. 00:40:23.000 --> 00:40:25.000 This… 00:40:25.000 --> 00:40:29.000 cross-section from a creosote site in california 00:40:29.000 --> 00:40:34.000 It shows that although this was a very heterogeneous 00:40:34.000 --> 00:40:37.000 strata here at this site 00:40:37.000 --> 00:40:47.000 the creosote shown in red is making its way down through it. You pass through clean soils and then encounter Napple again. 00:40:47.000 --> 00:40:50.000 in several different locations. 00:40:50.000 --> 00:40:53.000 And what we use is what we use 00:40:53.000 --> 00:41:00.000 bottom, you know, the maximum depth at this site for the characterization. 00:41:00.000 --> 00:41:06.000 Once this gravel and sand layer at the bottom, which is at 250 feet below ground surface. 00:41:06.000 --> 00:41:10.000 And groundwater concentrations in that 00:41:10.000 --> 00:41:15.000 gravel and sand unit do indicate the presence of napple. 00:41:15.000 --> 00:41:20.000 very high concentrations in that zone. 00:41:20.000 --> 00:41:32.000 But that was also permeable enough that we believe it's not going to, you know, Napa would not accumulate to then migrate even further. 00:41:32.000 --> 00:41:36.000 into a lower permeability zone below that, but it's likely going to spread laterally 00:41:36.000 --> 00:41:42.000 in that zone and that is indeed what we are seeing from the data. 00:41:42.000 --> 00:41:53.000 In other cases, the bean apple may be pooled on top of a competent bedrock 00:41:53.000 --> 00:41:56.000 One thing we haven't. 00:41:56.000 --> 00:42:03.000 And I haven't used on the sites I've worked on, but I saw in a research paper was to look for the NAPL 00:42:03.000 --> 00:42:09.000 to the depth of the deepest groundwater contamination. And I think that there's that's probably 00:42:09.000 --> 00:42:12.000 good advice if you don't really know 00:42:12.000 --> 00:42:17.000 how deep you should go. If you have an idea already as to how deep 00:42:17.000 --> 00:42:21.000 the dissolve phase concentration goes. 00:42:21.000 --> 00:42:23.000 that my it 00:42:23.000 --> 00:42:26.000 probably behooves you to look that deep then then for 00:42:26.000 --> 00:42:27.000 an apple. 00:42:27.000 --> 00:42:32.000 Dr. Davis, just a quick time check. We're at 1.48 p.m. Eastern. 00:42:32.000 --> 00:42:36.000 Okay, I'm trying to speed this up a little bit. 00:42:36.000 --> 00:42:40.000 As I have said before, too. 00:42:40.000 --> 00:42:47.000 Napples can flow through low permeability soils and a lot of what they call aquitards 00:42:47.000 --> 00:42:49.000 have more 00:42:49.000 --> 00:43:01.000 permeable zones within them. As you can see in this cross section here. This is again a creosote site on the Pacific Northwest. 00:43:01.000 --> 00:43:03.000 the aquitard. 00:43:03.000 --> 00:43:12.000 have higher permeability zones in it. The creosote was making its way through it and towards the bottom of the 00:43:12.000 --> 00:43:18.000 of the aquitard. So to say that you're going to 00:43:18.000 --> 00:43:20.000 stop. 00:43:20.000 --> 00:43:25.000 your vertical exploration, when you reach a low permeability zone 00:43:25.000 --> 00:43:30.000 may mean that you're missing a lot of the lower 00:43:30.000 --> 00:43:39.000 contamination that is, you're missing a lot of the contamination that has migrated into those low permeability soils 00:43:39.000 --> 00:43:52.000 And here's that El Naples site I mentioned a little bit ago. At 155 feet below ground surface, excuse me, let's try that again. 00:43:52.000 --> 00:43:54.000 At 110, 00:43:54.000 --> 00:44:00.000 55 feet below ground surface, NAPA was detected in these areas. 00:44:00.000 --> 00:44:03.000 that are shown here in blue. 00:44:03.000 --> 00:44:07.000 But then the 00:44:07.000 --> 00:44:12.000 at an elevation of about 215 feet below 00:44:12.000 --> 00:44:14.000 ground surface 00:44:14.000 --> 00:44:19.000 The Napple was actually much had a much wider distribution 00:44:19.000 --> 00:44:25.000 And so you start where you know that there was NAPPL and you keep 00:44:25.000 --> 00:44:30.000 stepping out until you've found all of it. And we haven't used a 00:44:30.000 --> 00:44:36.000 a triad approach for characterizing this site, but we've had 00:44:36.000 --> 00:44:38.000 to do multiple 00:44:38.000 --> 00:44:42.000 work plans and reports of well installations 00:44:42.000 --> 00:44:45.000 But I think that we've 00:44:45.000 --> 00:44:51.000 Well, there's a couple areas we probably still don't have it fully characterized at the greatest depth 00:44:51.000 --> 00:44:56.000 that that jet fuel has made it to. 00:44:56.000 --> 00:45:02.000 what is the groundwater data tell you? You really have to 00:45:02.000 --> 00:45:06.000 take that data in context. 00:45:06.000 --> 00:45:15.000 What I'm showing here is areas, and this was a waste oil site where we did a thermal remediation and the area for 00:45:15.000 --> 00:45:18.000 to be treated with thermal 00:45:18.000 --> 00:45:21.000 technology is outlined in red here. 00:45:21.000 --> 00:45:31.000 And the figure on the left is the baseline groundwater concentrations. And you can see that the highest concentration detected at that point 00:45:31.000 --> 00:45:34.000 What's just outside of our designated 00:45:34.000 --> 00:45:36.000 treatment area. 00:45:36.000 --> 00:45:41.000 But when we started heating. 00:45:41.000 --> 00:45:49.000 Then we see that that high concentration that had been just outside of our treatment area, that went away pretty quickly. 00:45:49.000 --> 00:45:56.000 But the concentrations within the treatment area went up significantly. When you start hitting it, you're going to 00:45:56.000 --> 00:46:00.000 dissolve more of that 00:46:00.000 --> 00:46:04.000 of the NAPL and you really start 00:46:04.000 --> 00:46:09.000 mixing things up, it becomes much more of a dynamic situation. 00:46:09.000 --> 00:46:15.000 And then the fact that there was an apple then there in that area was then 00:46:15.000 --> 00:46:18.000 observed. 00:46:18.000 --> 00:46:21.000 by the groundwater concentrations. 00:46:21.000 --> 00:46:24.000 And so, like I said, you have to be a little careful about 00:46:24.000 --> 00:46:27.000 how you 00:46:27.000 --> 00:46:32.000 interpret groundwater data. And this is not the only 00:46:32.000 --> 00:46:37.000 site where I've seen this type of thing where, you know, initially based around 00:46:37.000 --> 00:46:39.000 baseline concentrations weren't that high. 00:46:39.000 --> 00:46:43.000 But then we start heating it up and you know we're 00:46:43.000 --> 00:46:48.000 remove enough mass that we know that there was an apple there, although it wasn't indicated. 00:46:48.000 --> 00:46:55.000 by the groundwater data in the baseline. 00:46:55.000 --> 00:47:02.000 looking a little bit more as to what you use to indicate the presence of Napple. 00:47:02.000 --> 00:47:05.000 At this site. 00:47:05.000 --> 00:47:16.000 This is one of those sites where the responsible party wanted to say that there is so much DAPLA out there over such a large area that it's just too expensive to try to remediate the site. 00:47:16.000 --> 00:47:19.000 So the potential 00:47:19.000 --> 00:47:27.000 Nappal area that's shown by the outline in green, that was based on 1% 00:47:27.000 --> 00:47:31.000 VOCs detected at 1% of their solubility. 00:47:31.000 --> 00:47:36.000 in the groundwater and you can see that's a pretty large area 00:47:36.000 --> 00:47:42.000 what they call the probable Dean Apple zone 00:47:42.000 --> 00:47:45.000 here with the green hatch marks 00:47:45.000 --> 00:47:48.000 That was determined. 00:47:48.000 --> 00:47:53.000 And by the area that had uh where they 00:47:53.000 --> 00:47:55.000 found uh 00:47:55.000 --> 00:47:59.000 or where they detected alcohols in the groundwater. 00:47:59.000 --> 00:48:07.000 The thought being that as NAPL degraded, it was producing alcohols. And so this was an apple 00:48:07.000 --> 00:48:10.000 contaminated area. 00:48:10.000 --> 00:48:20.000 And then where the black circles are, there they had groundwater concentrations that were greater than 10%. 00:48:20.000 --> 00:48:24.000 of the solubility of the VOCs. 00:48:24.000 --> 00:48:28.000 And you can see that there are several of those 00:48:28.000 --> 00:48:33.000 high groundwater concentrations here in the southern area of the 00:48:33.000 --> 00:48:36.000 probable zone. 00:48:36.000 --> 00:48:46.000 But when we went back and looked for Dean Apple visibly or with dyes, as you can see here in soil cores 00:48:46.000 --> 00:48:53.000 and use that to delineate the NAPL area. 00:48:53.000 --> 00:48:56.000 then. 00:48:56.000 --> 00:49:00.000 Then what we found is that this area outlined in purple 00:49:00.000 --> 00:49:05.000 was the only area where NAPA was actually present. 00:49:05.000 --> 00:49:08.000 And we then used 00:49:08.000 --> 00:49:14.000 thermal conductive heating to treat that knackel contaminated area. 00:49:14.000 --> 00:49:24.000 and removed over 450,000 pounds of contaminants of waste oils and chlorine solvents from that area. 00:49:24.000 --> 00:49:27.000 And then the downgrading area 00:49:27.000 --> 00:49:30.000 cleaned up pretty rapidly. 00:49:30.000 --> 00:49:35.000 Which tells us that we really did. 00:49:35.000 --> 00:49:39.000 treat essentially all of the NAPA contaminated area 00:49:39.000 --> 00:49:44.000 efficiently, effectively. 00:49:44.000 --> 00:49:49.000 the pump and treat system there, I believe has been turned off now. 00:49:49.000 --> 00:49:52.000 breached their cleanup goals. 00:49:52.000 --> 00:50:03.000 coal tar and creosote in particular a lot of times are almost always are adjacent to surface water bodies. So sometimes you have to be able to 00:50:03.000 --> 00:50:09.000 look at the soils below those surface water bodies. This was a 00:50:09.000 --> 00:50:13.000 scaps rig. It was LIF being deployed 00:50:13.000 --> 00:50:19.000 in a slew adjacent to a creosote site and it 00:50:19.000 --> 00:50:22.000 they had to support 00:50:22.000 --> 00:50:32.000 the tool as it was going through the open water until it actually reached the sediments below it, but this was effective in being able to explore those 00:50:32.000 --> 00:50:34.000 sediments 00:50:34.000 --> 00:50:37.000 below the slew. 00:50:37.000 --> 00:50:43.000 You have to consider the character, the quality of the characterization data. 00:50:43.000 --> 00:50:55.000 Especially when you're looking for VOCs that are so volatile, you open up the core to the atmosphere and you can lose significant quantity 00:50:55.000 --> 00:51:02.000 of the VOCs, a significant proportion of the VOCs. 00:51:02.000 --> 00:51:04.000 So you want to 00:51:04.000 --> 00:51:14.000 protect the core the soils as much as you can as you determine where you want to take those analytical samples. 00:51:14.000 --> 00:51:20.000 One technique that has been employed is to split that soil core in half. 00:51:20.000 --> 00:51:27.000 And cover half of it with foil to reduce the evaporation of the VOCs from that half. 00:51:27.000 --> 00:51:30.000 While you quickly scan the other half 00:51:30.000 --> 00:51:37.000 with the PID to determine where the highest concentrations are likely are located. 00:51:37.000 --> 00:51:39.000 And then you 00:51:39.000 --> 00:51:44.000 get those soil samples for analysis from the other half of the core 00:51:44.000 --> 00:51:48.000 that has been covered to reduce the evaporation from it. 00:51:48.000 --> 00:51:59.000 And as I've said before, I really recommend samples be obtained every five to 10 feet of the soil core. 00:51:59.000 --> 00:52:03.000 And even doing that 00:52:03.000 --> 00:52:07.000 Those soil cores, a four inch diameter core 00:52:07.000 --> 00:52:14.000 it is really just like looking at a soda straw of uh 00:52:14.000 --> 00:52:21.000 you know from the site is a very small portion of the subsurface that's being examined by those soil cores. 00:52:21.000 --> 00:52:25.000 And so that's where groundwater data 00:52:25.000 --> 00:52:28.000 can be helpful. 00:52:28.000 --> 00:52:31.000 in determining the 00:52:31.000 --> 00:52:34.000 presence of the contaminants. 00:52:34.000 --> 00:52:39.000 When you get a groundwater sample from a monitoring well, you are generally querying a larger area. 00:52:39.000 --> 00:52:45.000 Like I say, sometimes there's interpretation problems, but where you do find high 00:52:45.000 --> 00:52:51.000 concentrations in the groundwater, that may very well 00:52:51.000 --> 00:52:57.000 indicate to you the most likely areas for the NAPL presence. 00:52:57.000 --> 00:53:02.000 And you do need to practice the 00:53:02.000 --> 00:53:11.000 proper techniques for obtaining those samples of the low flow sampling and removing the stagnant water from the well bore. 00:53:11.000 --> 00:53:14.000 And ensuring that you get a good sample 00:53:14.000 --> 00:53:19.000 that does not have air bubbles. We saw that problem at a site just very recently. 00:53:19.000 --> 00:53:26.000 And also, too, you know, you got to collect that sample directly into the containers. You don't 00:53:26.000 --> 00:53:30.000 pour water samples back and forth between containers because 00:53:30.000 --> 00:53:36.000 That also will vent VOCs. 00:53:36.000 --> 00:53:44.000 A lot of times with the screening tools, MIP and the LIF, the MIP in particular 00:53:44.000 --> 00:53:55.000 You can also do hydraulic profiling. They have small screens. I think they're generally two inches, two feet. 00:53:55.000 --> 00:54:00.000 or so in length where you can obtain 00:54:00.000 --> 00:54:06.000 groundwater samples from these temporary wells as you're doing the characterization. 00:54:06.000 --> 00:54:11.000 And we use that at one site you can see 00:54:11.000 --> 00:54:16.000 the numbers as shown in blue or 00:54:16.000 --> 00:54:18.000 blue-green on the blue on 00:54:18.000 --> 00:54:22.000 left-hand side of the core that 00:54:22.000 --> 00:54:32.000 cross section that's shown there, you see that they were getting relatively low concentrations of PAHs in those 00:54:32.000 --> 00:54:39.000 samples that were taken every 10 feet with that small length, short length of screen. 00:54:39.000 --> 00:54:42.000 And then they installed a well 00:54:42.000 --> 00:54:49.000 in the area where they had gotten the highest concentration from the 00:54:49.000 --> 00:54:51.000 temporary wells 00:54:51.000 --> 00:54:58.000 And they're found much higher concentrations of the PAHs. This was creosote site. 00:54:58.000 --> 00:55:02.000 So my caution here is that 00:55:02.000 --> 00:55:08.000 you know even doing this profiling every 10 feet 00:55:08.000 --> 00:55:12.000 you can still miss an area of high concentration because 00:55:12.000 --> 00:55:16.000 The plume may be coming off 00:55:16.000 --> 00:55:21.000 over a very limited area 00:55:21.000 --> 00:55:27.000 a higher permeability zone within a low permeability soils that you would miss 00:55:27.000 --> 00:55:30.000 that higher zone of higher zone 00:55:30.000 --> 00:55:35.000 that zone of higher concentrations. 00:55:35.000 --> 00:55:39.000 Hoping we don't run out of time here. 00:55:39.000 --> 00:55:49.000 Hopefully you always use a quap, a quality assurance project plan that ensures that your samples obtained for 00:55:49.000 --> 00:55:52.000 analysis uh are 00:55:52.000 --> 00:56:00.000 then stored properly with proper preservatives and proper shipping of the samples. 00:56:00.000 --> 00:56:05.000 ensure that holding times are met. You really need to become familiar with 00:56:05.000 --> 00:56:10.000 a lot of the QA procedures and what that uh 00:56:10.000 --> 00:56:14.000 information means when you're interpreting this data. 00:56:14.000 --> 00:56:22.000 And when you're using like an EPA method, 8270 for looking at PAHs and coal tar creosote. 00:56:22.000 --> 00:56:26.000 You got to realize that that method only 00:56:26.000 --> 00:56:30.000 identifies and quantifies 00:56:30.000 --> 00:56:37.000 a very small percentage of all of the compounds that are present in those 00:56:37.000 --> 00:56:41.000 in those napples. And so for when it comes to 00:56:41.000 --> 00:56:44.000 getting mass estimates of the napple 00:56:44.000 --> 00:56:52.000 You really need a total petroleum hydrocarbon measurement. And total petroleum hydrocarbons you can get 00:56:52.000 --> 00:56:57.000 normally at three different types, you get the gasoline range, the more volatile 00:56:57.000 --> 00:57:02.000 compounds, the intermediate range, the diesel range, and then those that are 00:57:02.000 --> 00:57:10.000 semi-volatile to non-volatile, oil and greece range, TPH, 00:57:10.000 --> 00:57:14.000 that really gives you a better number for looking at 00:57:14.000 --> 00:57:17.000 the total mass. 00:57:17.000 --> 00:57:22.000 And then data presentations so that you can understand the data 00:57:22.000 --> 00:57:35.000 is another very important part of this. The two cross sections on the left-hand side here come from 3D models that are quite popular these days, it seems. 00:57:35.000 --> 00:57:45.000 But as you can tell just by looking at groundwater concentrations and lithology separately on these two cross sections. 00:57:45.000 --> 00:57:49.000 You can't combine them so that you can 00:57:49.000 --> 00:57:51.000 You know, in what 00:57:51.000 --> 00:57:57.000 lithology, the highest concentrations exist. And that's a big problem that I have with this. 00:57:57.000 --> 00:58:00.000 And now this 00:58:00.000 --> 00:58:03.000 figure this on the right-hand side. 00:58:03.000 --> 00:58:14.000 Actually, you know, sort of the cartoon of what is being represented by this lithology cross-section on the bottom left-hand side. And you can see that they don't 00:58:14.000 --> 00:58:19.000 Well, it's a hard time making them match. 00:58:19.000 --> 00:58:29.000 And I know that when you've got these 3D programs on the computer, it can be fun to turn them all directions and look at 00:58:29.000 --> 00:58:33.000 these 3D figures from all these different views 00:58:33.000 --> 00:58:38.000 But in terms of understanding the data, I really find the old fashioned 00:58:38.000 --> 00:58:41.000 cross sections to be much more useful. 00:58:41.000 --> 00:58:49.000 This is a cross sections from a creosote site that we're trying to finish up the pre-design investigation on. 00:58:49.000 --> 00:58:53.000 And on this old fashioned cross section that's on paper 00:58:53.000 --> 00:59:00.000 It has not only the stratigraphy, which is shown by the different colors in the background. 00:59:00.000 --> 00:59:07.000 But the LIF results are shown on there and the squiggly lines that go from red to yellow to green and 00:59:07.000 --> 00:59:15.000 where there were visual observations of NAPA that's shown in the purplish color 00:59:15.000 --> 00:59:17.000 some of those borings. 00:59:17.000 --> 00:59:20.000 It shows the groundwater elevation. 00:59:20.000 --> 00:59:25.000 soil concentrations are given there along 00:59:25.000 --> 00:59:28.000 the soil core locations 00:59:28.000 --> 00:59:36.000 As well as groundwater concentrations from where there were monitoring wells. And this gives you then all of the 00:59:36.000 --> 00:59:44.000 information in one place. You can see better was the contamination in the more permeable units or was it 00:59:44.000 --> 00:59:50.000 Auras are also significant contamination within the lower permeability 00:59:50.000 --> 00:59:53.000 ability units or within the bedrock. 00:59:53.000 --> 00:59:59.000 So this method of visualization is much more useful to me. 00:59:59.000 --> 01:00:03.000 Contours is another way that we use to help us visualize 01:00:03.000 --> 01:00:12.000 characterization data, whether it's the potentiometric surface that indicates groundwater flow direction or groundwater concentrations. 01:00:12.000 --> 01:00:20.000 But these contours can be very misleading, if not all of the wells are sampled. If you're comparing 01:00:20.000 --> 01:00:24.000 contours from one time to the next time. 01:00:24.000 --> 01:00:27.000 But you didn't sample all the same wells 01:00:27.000 --> 01:00:31.000 you may get very misleading contour 01:00:31.000 --> 01:00:35.000 contours then develop from them that they're not really 01:00:35.000 --> 01:00:40.000 good for comparing, you know, to see if uh 01:00:40.000 --> 01:00:44.000 the plume is changing with time. 01:00:44.000 --> 01:00:48.000 And often too then, you know, when they encounter napa in a well. 01:00:48.000 --> 01:00:54.000 They don't like to really get the napple within the pumps, contaminate uh 01:00:54.000 --> 01:01:00.000 all of the tubing and all. And so I often don't take a groundwater sample from a well that contains an apple. 01:01:00.000 --> 01:01:08.000 And so then if you don't have that data, which likely, you know, that well likely has very high concentrations. 01:01:08.000 --> 01:01:12.000 But you don't have that concentration data to include in the contour. 01:01:12.000 --> 01:01:14.000 And so, and so 01:01:14.000 --> 01:01:21.000 you're probably drawing contours that really are misleading because they're not showing where the highest concentrations are. 01:01:21.000 --> 01:01:26.000 And sometimes, you know, when it comes to the potentiometric surfaces. 01:01:26.000 --> 01:01:33.000 You know, the integrity of the well or the ground surface elevation can change, meaning that your survey data 01:01:33.000 --> 01:01:35.000 is no longer 01:01:35.000 --> 01:01:40.000 correct. And so when you calculate the water table elevation 01:01:40.000 --> 01:01:46.000 it may not show the actual potentiometric surface. 01:01:46.000 --> 01:01:52.000 In this case that I'm showing here, this potentiometric surface 01:01:52.000 --> 01:02:00.000 It shows the lowest water level at the monitoring well mw uh 01:02:00.000 --> 01:02:02.000 O3S. 01:02:02.000 --> 01:02:06.000 And the text part of it says that the text part says 01:02:06.000 --> 01:02:10.000 the groundwater flows towards that monetary well. 01:02:10.000 --> 01:02:17.000 Well, what this doesn't show you is that, and these are shallow monitoring wells, this is a shallow water table. 01:02:17.000 --> 01:02:23.000 I said, there was a dish that ran parallel to this railroad tracks that's shown on here. 01:02:23.000 --> 01:02:28.000 There was approximately 10 feet deep and it had water in the bottom of it. 01:02:28.000 --> 01:02:31.000 And so… 01:02:31.000 --> 01:02:34.000 a more likely explanation here is not that 01:02:34.000 --> 01:02:39.000 somehow this monitoring well is a sink and all the water is flowing towards it 01:02:39.000 --> 01:02:45.000 But the more logical explanation is that the groundwater 01:02:45.000 --> 01:02:49.000 on either side of that ditch is discharging into the ditch. 01:02:49.000 --> 01:02:52.000 And so… 01:02:52.000 --> 01:02:57.000 And I've seen so many potentiometric surfaces drawn that 01:02:57.000 --> 01:02:59.000 we're not really showing 01:02:59.000 --> 01:03:13.000 how groundwater flows. I just got to caution you to, you know, don't give up your critical thinking and think that some because someone put the line there that's really you know what the case is. 01:03:13.000 --> 01:03:15.000 Okay. 01:03:15.000 --> 01:03:18.000 To conclude this. 01:03:18.000 --> 01:03:25.000 the message to take to the field, making use of the triad approach 01:03:25.000 --> 01:03:30.000 And responding to the data that you're getting in the field can reduce the number of mobilizations 01:03:30.000 --> 01:03:41.000 that are needed to fully characterize the site and therefore greatly reduce the time and costs of the characterization. 01:03:41.000 --> 01:03:53.000 It can be more complex to contract it with drillers when you don't know exactly how many borings you're going to need. 01:03:53.000 --> 01:03:55.000 You can have… 01:03:55.000 --> 01:04:02.000 specify a total number with some of them being contingencies. You can award additional 01:04:02.000 --> 01:04:09.000 boring since they go. I know that for government, having been an EPA employee for so many years, I know that this contract he can be 01:04:09.000 --> 01:04:15.000 more complicated for government, but it can be done 01:04:15.000 --> 01:04:24.000 And then, too, it does take more coordination of the project team that's back in the office with the field personnel. 01:04:24.000 --> 01:04:32.000 But we have enough ways of sharing data nowadays that it is very doable. We did it 20 years ago. 01:04:32.000 --> 01:04:39.000 and more when we were characterizing a couple of creosote sites and with the communication 01:04:39.000 --> 01:04:48.000 vehicles that we have now, that can be done. And of course, too, is always good for the whole project team even those 01:04:48.000 --> 01:04:55.000 back in the office to get out and see the field work. 01:04:55.000 --> 01:05:02.000 part of at least for a day or two during that characterization work. 01:05:02.000 --> 01:05:06.000 So my conclusions on characterization. 01:05:06.000 --> 01:05:08.000 We have learned 01:05:08.000 --> 01:05:12.000 Over the years, I think a lot more about 01:05:12.000 --> 01:05:17.000 how to approach the characterization. We've got more and better tools now i think 01:05:17.000 --> 01:05:21.000 that the experience is there to 01:05:21.000 --> 01:05:24.000 allow us to better interpret that data 01:05:24.000 --> 01:05:30.000 But my experience is I'm not totally seeing that 01:05:30.000 --> 01:05:37.000 being carried over into the field yet. There's more education that needs to be done and i don't 01:05:37.000 --> 01:05:43.000 generally the field work is done by some of the least experienced personnel, those that are fresh out of school. 01:05:43.000 --> 01:05:51.000 But we do need to make sure that they have the proper training and instruction to perform the work correctly and to 01:05:51.000 --> 01:05:59.000 get good information because then we're making some pretty costly decisions based on that data as to 01:05:59.000 --> 01:06:10.000 choosing a remedial technology and designing and implementing that technology to be effective. 01:06:10.000 --> 01:06:18.000 a natural delineation generally requires multiple lines of evidence, unless it's one of these NAPPLs you know like 01:06:18.000 --> 01:06:27.000 coal tar creosote that are very visible within the soils. 01:06:27.000 --> 01:06:35.000 And I'll say it again. I know I've said it several times, but soil concentrations really are the best data for estimating mass. 01:06:35.000 --> 01:06:40.000 And with that, I will try to take your questions. 01:06:40.000 --> 01:06:43.000 And do my best to answer them. 01:06:43.000 --> 01:06:52.000 All right. Thank you so very much, Dr. Davis. Let me remind the audience that if you haven't yet submitted your question into the Q&A, you can certainly do so 01:06:52.000 --> 01:06:57.000 I have a series of questions that are already in the queue, and I'm going to start with those. 01:06:57.000 --> 01:07:06.000 Now, there are a wide array of questions. I wish I could kind of group them together, but they really are sort of very unique and specific. So I'm just going to 01:07:06.000 --> 01:07:09.000 start to take these chronologically. 01:07:09.000 --> 01:07:22.000 This first question is in regards to lift technology. One of our attendees asks, could it speciate between PAHs and weathered TPHs? 01:07:22.000 --> 01:07:27.000 Maybe if you get… 01:07:27.000 --> 01:07:30.000 really into… 01:07:30.000 --> 01:07:32.000 The… 01:07:32.000 --> 01:07:38.000 into the waveforms as to what color 01:07:38.000 --> 01:07:42.000 is being transmitted back. 01:07:42.000 --> 01:07:45.000 But I think that would be a really 01:07:45.000 --> 01:07:55.000 difficult thing to discern from an LIF. I think really your easier thing to do then is to 01:07:55.000 --> 01:08:01.000 get a sample. If you can get an apple sample out of a well 01:08:01.000 --> 01:08:05.000 And have it analyzed or just have uh get a 01:08:05.000 --> 01:08:12.000 soil core and actually analyze it within the soil 01:08:12.000 --> 01:08:25.000 that is probably going to give you more reliable information in terms of speciation than the fluorescence is going to. 01:08:25.000 --> 01:08:26.000 Okay. 01:08:26.000 --> 01:08:28.000 Okay. We have another question about MIP data. 01:08:28.000 --> 01:08:33.000 Does MIP data indicate relative concentration? 01:08:33.000 --> 01:08:38.000 Not very well. As I showed 01:08:38.000 --> 01:08:43.000 The… 01:08:43.000 --> 01:08:46.000 It was way back there and that way back there 01:08:46.000 --> 01:08:49.000 there is some maybe… 01:08:49.000 --> 01:08:57.000 correlation between concentration in the soil and your MIP response, but then there's other ones like this 01:08:57.000 --> 01:09:00.000 You know, this green dot here where 01:09:00.000 --> 01:09:08.000 what the MIP was showing was a couple of orders of magnitude off from what 01:09:08.000 --> 01:09:12.000 was found and actually found in the soil core. 01:09:12.000 --> 01:09:14.000 And… 01:09:14.000 --> 01:09:22.000 So there is some linearity in some of this data here but 01:09:22.000 --> 01:09:28.000 Most of the Rs from a linear regression uh 01:09:28.000 --> 01:09:30.000 do not show a good correlation. 01:09:30.000 --> 01:09:41.000 R squared to 0.61, 0.48, 0.6. And now for the saturated soils, it was showing a better correlation. 01:09:41.000 --> 01:09:46.000 But still, too. 01:09:46.000 --> 01:09:51.000 This is all very site-specific. Different 01:09:51.000 --> 01:09:53.000 response too and in response to 01:09:53.000 --> 01:10:01.000 types of soil, a different response in clay soils versus what you would get in sandy soils. 01:10:01.000 --> 01:10:05.000 So, um. 01:10:05.000 --> 01:10:07.000 the best thing to do is to 01:10:07.000 --> 01:10:13.000 use the MIP data as an indication of the presence of the contaminants. 01:10:13.000 --> 01:10:17.000 And then get your soil samples to get a better 01:10:17.000 --> 01:10:20.000 quantification of what's there. 01:10:20.000 --> 01:10:24.000 Okay. We have a question about PID levels. 01:10:24.000 --> 01:10:30.000 And Napple. What PID levels would be indicative of NAPL? 01:10:30.000 --> 01:10:37.000 That can be all over the place too, looking at this one. 01:10:37.000 --> 01:10:40.000 they were getting a lot of very low 01:10:40.000 --> 01:10:47.000 PID readings, even when the concentrations were quite high, you got 01:10:47.000 --> 01:10:51.000 several orders of magnitude difference there and some of it 01:10:51.000 --> 01:10:55.000 can be how you can be how 01:10:55.000 --> 01:11:01.000 screen the soil with a PID. 01:11:01.000 --> 01:11:07.000 different ways of doing it can give different results. Just running the 01:11:07.000 --> 01:11:14.000 PID tip along the soil core might give you low numbers if you actually take 01:11:14.000 --> 01:11:24.000 a small sample of that soil and put it into a baggie and seal the baggie, give it a moment or a little bit of time for 01:11:24.000 --> 01:11:29.000 the volatiles that are in that soil then to go into the vapor phase 01:11:29.000 --> 01:11:34.000 And then puncture the bag with the tip of that 01:11:34.000 --> 01:11:40.000 PID and get a reading that might give you something that is more meaningful than just 01:11:40.000 --> 01:11:46.000 running the tip of the PID over the soil core 01:11:46.000 --> 01:11:53.000 But still, there's not a good correlation there. You really do have to have the 01:11:53.000 --> 01:11:58.000 the analytical results to know the mass that's there. 01:11:58.000 --> 01:12:08.000 Okay. Someone asked a related question about lines of evidence. They were just wondering, do you have a recommendation of how many lines of evidence they might need to prove NAPPL? 01:12:08.000 --> 01:12:11.000 two, three, ten. 01:12:11.000 --> 01:12:15.000 I'd say it's generally about three. 01:12:15.000 --> 01:12:16.000 Okay. 01:12:16.000 --> 01:12:26.000 Looking at PID tells you that something is there. The analytical result, and that's something you have to 01:12:26.000 --> 01:12:35.000 you know, is site specific and maybe specific for a certain soil type at that site 01:12:35.000 --> 01:12:42.000 As to what concentration, you know, in the analytical sample really indicates an apple, but that's something you can determine. 01:12:42.000 --> 01:12:49.000 And then something like the flutie ribbon or a die that would 01:12:49.000 --> 01:12:51.000 indicate. 01:12:51.000 --> 01:12:57.000 NAPPL are good lines of evidence. 01:12:57.000 --> 01:13:03.000 Okay. All right. There was a statement when you were discussing LIF. 01:13:03.000 --> 01:13:06.000 And about another technology. 01:13:06.000 --> 01:13:09.000 One of the attendees said that it's important 01:13:09.000 --> 01:13:13.000 to note that while a lot of the discussion on LIF 01:13:13.000 --> 01:13:15.000 that was shown today. 01:13:15.000 --> 01:13:18.000 was showing OIP log data. 01:13:18.000 --> 01:13:28.000 This is similar to LIF, but OIP is a different tool that does not utilize a laser, but rather an LED to 01:13:28.000 --> 01:13:31.000 excited institute PAHs. 01:13:31.000 --> 01:13:36.000 And they just note that it might be useful to look at both tools. 01:13:36.000 --> 01:13:42.000 Because they say they've seen that both are proven to effectively detect PAHs in soil and groundwater. 01:13:42.000 --> 01:13:50.000 So I'm not sure if you can talk a little bit between OIP versus LIF and your experience with them. 01:13:50.000 --> 01:14:00.000 And I believe that you're right. Although when we use 01:14:00.000 --> 01:14:04.000 OIP, they were still calling it LIP. 01:14:04.000 --> 01:14:12.000 But I believe that you're correct. I believe that Randy St. Germain from Dakota Technologies has uh 01:14:12.000 --> 01:14:20.000 Has school be in that sum, although I was not the one who chose the vendor. 01:14:20.000 --> 01:14:22.000 for 01:14:22.000 --> 01:14:30.000 that use this tool at this creosote site where we were 01:14:30.000 --> 01:14:32.000 and there's 01:14:32.000 --> 01:14:34.000 What we ended up doing 01:14:34.000 --> 01:14:36.000 at this site was at this site 01:14:36.000 --> 01:14:41.000 then determining a threshold response 01:14:41.000 --> 01:14:45.000 that indicated the presence of NAPL. 01:14:45.000 --> 01:14:51.000 And what we saw when comparing this to the 01:14:51.000 --> 01:14:53.000 soil cores 01:14:53.000 --> 01:14:55.000 was that 01:14:55.000 --> 01:14:59.000 where we were seeing a 50% response 01:14:59.000 --> 01:15:04.000 we generally had 01:15:04.000 --> 01:15:08.000 visible creosote within the soils. 01:15:08.000 --> 01:15:12.000 And that was what we used then. 01:15:12.000 --> 01:15:15.000 evaluating the evaluating 01:15:15.000 --> 01:15:18.000 this data to determine where 01:15:18.000 --> 01:15:20.000 where there was NAPPL. 01:15:20.000 --> 01:15:30.000 where there was a response that was greater than 50%. 01:15:30.000 --> 01:15:37.000 And that did seem to work fairly well. One thing that 01:15:37.000 --> 01:15:41.000 I found very disconcerting when 01:15:41.000 --> 01:15:49.000 We started on this project and we're doing the planning for it. The consultant had no plans for 01:15:49.000 --> 01:15:57.000 getting soil cores adjacent to these locations in order to validate these responses. 01:15:57.000 --> 01:16:03.000 And that was something I had to fight for. But we did then uh 01:16:03.000 --> 01:16:14.000 I did finally convince them that it needed to be done. And then when we came to the realization that 01:16:14.000 --> 01:16:17.000 there really wasn't. 01:16:17.000 --> 01:16:22.000 Well, I already knew it, but they finally came to the realization that the 01:16:22.000 --> 01:16:26.000 response wasn't necessarily correlated to 01:16:26.000 --> 01:16:32.000 PAH concentration in the soils, then we did determine the 01:16:32.000 --> 01:16:34.000 threshold. 01:16:34.000 --> 01:16:37.000 and use the data in that way. 01:16:37.000 --> 01:16:46.000 And I think that that is more the way that that data is supposed to be used. 01:16:46.000 --> 01:16:47.000 Bye. 01:16:47.000 --> 01:16:50.000 Okay. We had a question. I'm just going to move on to this one. 01:16:50.000 --> 01:16:57.000 Have you observed desiccation of betonite from contact with Dean Apple in the subsurface? 01:16:57.000 --> 01:17:01.000 They wonder, is betonite a right annular seal material 01:17:01.000 --> 01:17:07.000 for around a thump in a Dean Apple recovery well. 01:17:07.000 --> 01:17:12.000 It may very well not be. There has been some… 01:17:12.000 --> 01:17:24.000 work done by some years ago by colleagues of mine here at Kerr Lab looking at the effect of different NAPPLs on 01:17:24.000 --> 01:17:27.000 on bentonite. 01:17:27.000 --> 01:17:35.000 it may very well not be that I can probably get you a link to that that can be provided 01:17:35.000 --> 01:17:37.000 then… 01:17:37.000 --> 01:17:40.000 I'm sure that Gene can provide then to the group 01:17:40.000 --> 01:17:50.000 for a groundwater issue paper that was written, like I say, some years ago looking at compatibility of napples with 01:17:50.000 --> 01:17:53.000 with bentonite. 01:17:53.000 --> 01:18:02.000 And in fact, too, Bet and I, you know, I work a lot with thermal remediation and the bentonite will also be desiccated by heat 01:18:02.000 --> 01:18:06.000 And so, you know, we use 01:18:06.000 --> 01:18:17.000 a cement grout on wells for thermal systems. And that would be more appropriate probably in the 01:18:17.000 --> 01:18:20.000 for a sump in a Dean Apple area. 01:18:20.000 --> 01:18:21.000 that will stand up. 01:18:21.000 --> 01:18:22.000 Okay. 01:18:22.000 --> 01:18:27.000 to most napples. 01:18:27.000 --> 01:18:31.000 Okay. I'm going to take us back to a real quick 01:18:31.000 --> 01:18:34.000 termed a question on slide eight 01:18:34.000 --> 01:18:37.000 There were two acronyms on slide eight. 01:18:37.000 --> 01:18:42.000 NAS and SRS. 01:18:42.000 --> 01:18:49.000 Oh, those indicated at what site the data had been obtained. 01:18:49.000 --> 01:18:50.000 Okay. 01:18:50.000 --> 01:18:53.000 SRS. 01:18:53.000 --> 01:18:58.000 Savannah River site NAS, I'm not sure. 01:18:58.000 --> 01:18:59.000 Okay. 01:18:59.000 --> 01:19:04.000 But this goes back then to the research that was done on the development of the MIP. 01:19:04.000 --> 01:19:08.000 Okay. We have another question. 01:19:08.000 --> 01:19:11.000 I think… 01:19:11.000 --> 01:19:19.000 Let me go with this one. Someone is looking for recommendations for tools for a rugged or hilly landscape. 01:19:19.000 --> 01:19:28.000 They note that there is almost no flat surface for them to work with. 01:19:28.000 --> 01:19:31.000 Um… 01:19:31.000 --> 01:19:36.000 And I guess it would depend upon just how steep it is. 01:19:36.000 --> 01:19:40.000 But some of the 01:19:40.000 --> 01:19:44.000 instruments that are geoprobe 01:19:44.000 --> 01:19:51.000 some of the geoprobes are made to go into rather challenging areas, I believe. 01:19:51.000 --> 01:19:59.000 You might check with what is available from 01:19:59.000 --> 01:20:11.000 as a geo probe because then a geoprobe a lot of times can deploy these same screening tools, you know, the MIP or the LIF, the CPT can. 01:20:11.000 --> 01:20:16.000 And I know that Geopro makes some 01:20:16.000 --> 01:20:20.000 rigs that can go into 01:20:20.000 --> 01:20:23.000 wetlands and marshy areas. 01:20:23.000 --> 01:20:27.000 that might be your best bet for something 01:20:27.000 --> 01:20:31.000 in areas where you don't have 01:20:31.000 --> 01:20:35.000 level ground to work on. 01:20:35.000 --> 01:20:36.000 Okay. 01:20:36.000 --> 01:20:43.000 Okay. I'll just bring in a comment here that one attendee was sharing regarding an earlier question. 01:20:43.000 --> 01:20:49.000 One of the participants said, in reference to the need to differentiate creosote and TPH, 01:20:49.000 --> 01:20:56.000 They're familiar with a group known as Dakota Technologies who can use waveform analysis and plotting 01:20:56.000 --> 01:21:03.000 to determine whether or not LIF results correlate with known NAPL, so diesel, motor oil, coal tar, et cetera, clusters. 01:21:03.000 --> 01:21:13.000 So if you're able to collect site-specific NAPPL samples, you can then also incorporate those to further differentiate the LIF results. 01:21:13.000 --> 01:21:26.000 Yeah, like I say, I still think that my first, for me, my first instinct would still be to analyze a sample. 01:21:26.000 --> 01:21:27.000 Okay. 01:21:27.000 --> 01:21:34.000 And then do that. As I showed, you know, the dialif that i showed the 01:21:34.000 --> 01:21:37.000 the data from. 01:21:37.000 --> 01:21:44.000 You know, this is, of course, decoded technologies as well and it gets pretty complicated 01:21:44.000 --> 01:21:47.000 in terms of being able to 01:21:47.000 --> 01:21:56.000 interpret the waveforms with that. And it's still just implying 01:21:56.000 --> 01:21:59.000 something. 01:21:59.000 --> 01:22:03.000 And Randy might not be too happy hearing me say that type of thing but 01:22:03.000 --> 01:22:07.000 I think I'd hang my hat better on the analytical data. 01:22:07.000 --> 01:22:09.000 Okay. Okay. 01:22:09.000 --> 01:22:15.000 We've had a few people who asked questions for more information about the triad approach. 01:22:15.000 --> 01:22:24.000 And I just wanted to let you know that I have the URL of where they can find information about the triad Approach that I've shared with everyone in the chat. 01:22:24.000 --> 01:22:25.000 Great. Thank you. 01:22:25.000 --> 01:22:32.000 So you can actually Google the triad approach. And if you include CLUIN or US EPA, that should trigger the results. 01:22:32.000 --> 01:22:39.000 But you'll find a website that was formerly known as Triad Central has been incorporated into our site at cluwen.org. 01:22:39.000 --> 01:22:45.000 So we have all of the triad resources up there and that's been placed as a message in the chat. 01:22:45.000 --> 01:22:59.000 I'm going to take one more question here, just noting the time. And this question is asking, in your experience, have you seen that historic drainage ditches have been a transport mechanism for Dean Apple 01:22:59.000 --> 01:23:09.000 And they note, they're looking at a case where Dean Apple is found at significant distances from its source, such as a wood treatment process area. 01:23:09.000 --> 01:23:14.000 So I think they're saying the source came from this treatment process area and they had these ditches on site. 01:23:14.000 --> 01:23:18.000 And there's… 01:23:18.000 --> 01:23:27.000 proposing that the Dean Apple is being found really far away from that source area because of these ditches. Have you seen it happen that way? 01:23:27.000 --> 01:23:38.000 Yeah, actually, this site, this DDT manufacturing facility that's in LA 01:23:38.000 --> 01:23:44.000 the stormwater runoff from that site that some of it went through the neighboring community. 01:23:44.000 --> 01:23:51.000 and carried an apple contaminants with it. Some of the drainage ditches made it 01:23:51.000 --> 01:23:57.000 to the Pacific Ocean and the contaminants are found 01:23:57.000 --> 01:23:59.000 within the 01:23:59.000 --> 01:24:01.000 on the pacific. 01:24:01.000 --> 01:24:04.000 shelf there. 01:24:04.000 --> 01:24:09.000 there all have been traced back to this site. 01:24:09.000 --> 01:24:12.000 And so, yes, stormwater drainage 01:24:12.000 --> 01:24:16.000 may very well be something, it may very well have carried 01:24:16.000 --> 01:24:24.000 Napa long distances, NAPA and other, you know, even dissolve phase contaminants, long distances from the source 01:24:24.000 --> 01:24:30.000 of the, you know, where they were discharged. 01:24:30.000 --> 01:24:32.000 So yes, I would say yes 01:24:32.000 --> 01:24:41.000 very definitely that that is a possibility at these sites where very large quantities of NAPL have been discharged. 01:24:41.000 --> 01:24:46.000 Okay. Well, we have come right up on that scheduled end time of 2.30 p.m. Eastern. 01:24:46.000 --> 01:24:52.000 So at this time, I'm going to draw our Q&A session to a close, but I want to thank you so much, Dr. Davis, for 01:24:52.000 --> 01:25:00.000 sharing your time and expertise with our audience today. And I do want to walk through a few quick final reminders before I close things out. 01:25:00.000 --> 01:25:06.000 Now, we will be joined by Dr. Davis on two more webinars that have been scheduled for early January. 01:25:06.000 --> 01:25:13.000 She just completed the sessions on NAPL migration in the subsurface and today's session on characterization approaches for various types of NAPPLs. 01:25:13.000 --> 01:25:20.000 She'll come back and join us in early 25 on January 7th for a session on thermal remediation of Napples 01:25:20.000 --> 01:25:25.000 And then she'll close out the series on January 8th, where we look at challenges 01:25:25.000 --> 01:25:29.000 that were met and she's going to go through a series of case studies on thermal remediation. 01:25:29.000 --> 01:25:40.000 So if you have not signed up for those two webinars, I put links to those in the chat as well. And then I've got some QR codes here up on the screen that you're welcome to scan, or you can visit us at the Cleanup Information Network. 01:25:40.000 --> 01:25:46.000 And search through our webinar calendar and you'll find both of those are open for registration right now. 01:25:46.000 --> 01:25:52.000 I do want to just do a quick couple of reminders. Again, I hope you're all subscribed for Tech Direct, our monthly newsletter. 01:25:52.000 --> 01:25:57.000 that I send out on the first of each month, which will highlight free technical resources that are available online. 01:25:57.000 --> 01:26:05.000 Websites, publications, online internet seminars, and even in-person conferences related to hazardous waste site characterization and cleanup. 01:26:05.000 --> 01:26:13.000 If you were not here in the beginning, remember there is a unique seminar homepage that was created for today's session. 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We hope that you found this to be a valuable expenditure of your time. 01:27:55.000 --> 01:28:00.000 And that I'll see you next year in 2025 when we carry on with this series. 01:28:00.000 --> 01:28:16.000 With that, I'll formally conclude today's live broadcast. Thank you so very much for joining us.