Subjective Standards and the Long-Term Liability of Vapor Intrusion

Video Transcription

Dane: Hello and welcome, everyone. My name is Dane Menke. I am the Digital Marketing Manager here at REGENESIS and Land Science. Before we get started with the webinar today, I have just a couple of administrative items to cover. Since we’re trying to keep this under an hour, today’s presentation will be conducted with the audiences’ audio settings on mute. This will minimize unwanted background noise from the large number of participants joining us today. If you have a question, we encourage you to ask it using the question feature located on the webinar panel. We’ll collect your questions and do our best to answer them at the end of the presentation. If we do not address your question, we’ll make an effort to follow up with you after the webinar. We are recording this webinar, and a link to the recording will be emailed to you once it is available. In order to continue to sponsor events that are of value and worthy of your time, we will be sending out a brief survey following the webinar to get your feedback.

In today’s webinar will focus on subjective standards and the long-term liability of vapor intrusion. With that, I’d like to introduce our presenters for today. We’re pleased to have with us Tom Hatton, CEO of Clean Vapor LLC. Tom is a highly sought after speaker, consultant and vapor mitigation system designer, with over 30 years of knowledge and expertise. He is an industry leading expert in delineating how environmental conditions and building dynamics lead to vapor intrusion. As a co-author and contributor to many state and national mitigation standards and guidance documents, Tom leads LSRP’s PEs and building owners through the increasingly complex regulatory landscape on vapor intrusion projects.

We’re also pleased to have with us today Jordan Knight, Central Region Manager at Land Science. Jordan’s role at Land Science includes providing technical support to Land Science clients, in the design and installation of TerraShield, MonoShield, Nitro-Seal, and Retro-Coat vapor mitigation systems, and educating the environmental community on advancements in vapor intrusion barrier technology, implementation and quality control. She has extensive experience managing brownfield and landfill redevelopment projects, where vapor intrusion barriers and venting systems have been implemented throughout the United States. All right, so that concludes our introduction. Now, I will hand things over to Tom Hatton to get us started.

Tom: Well, thank you for that introduction. I really appreciate it. And I really appreciate the opportunity to be with everyone today and talk about this very important topic. As mentioned, the webinar is subjective standards and long-term liability of vapor intrusion. Today’s topic, while not being so much a technical topic, may be the single most important discussion going on in vapor intrusion today. When I meet with industry leaders and business unit owners, they all seem to have one question. And what they’re asking about is, “How do we define our long-term liability, where we have multiple facilities, when we’re talking about mergers, acquisitions? How do we judge what the reserve set asides need to be for vapor intrusion, when there’s so many different documents saying so many different things, and we’re selling this company with multiple business units in different states?”

So, what we’re gonna go over today is we’re gonna define the liability in the framework of these inconsistent standards. We’re gonna talk about soil gas standards, indoor air standards, active system performance standards, passive systems/new construction. Jordan is gonna go into vapor barrier materials. We’re gonna talk about OM&M standards. And then we’re gonna look at some of the remedies that we can employ as we try to limit these long-term liabilities.

So, what is liability? Well, Webster’s defines it as the state of being responsible for something, especially under the law. And with these environmental problems that are contaminants, they took many decades for these problems to exist, these contaminants are on the groundwater, they’re gonna be with us for a long time. So what they do is they present a long-term liability. If it’s not going away anytime soon, if there’s chemicals in the groundwater and they’re flowing someplace, they’re not easily extractable, but what they will do is they will surface through the vadose zone, and they will present problems in buildings going into the future.

Liability from vapor intrusion is becoming increasingly frequent, and the cases in terms of suits are becoming more and more frequent. And last summer, there was a presentation that Susan Cooper made, and she put a slide on the screen. And it totally floored me. And what it graphed was the frequency of vapor intrusion lawsuits, and the tort awards. The frequency is going straight up like a ski slope. And the tort award amounts are also going straight up like a ski slope. It’s actually pretty scary if you think about it. And we’re in this industry, and we’re trying to advise our clients, and we’re trying to deal with it ourselves. There was a case, Kirk and Schaeffler, where as a TCE vapor intrusion scenario. And the tort award was $20 million. That’s not small change no matter who your insurance company is.

And what was even more unique about this one was $14 million of it was punitive, because the owner did not take proper action. And in the post analysis of this award, both attorneys recognize that they could not create a medical linkage between the TCE and this young woman’s cancer. But when you’re going before a jury, and someone has passed away, or someone is in a witness box, extremely sick, all conventional thinking is set aside and there are huge awards. So this is, you know, unfortunately, the state of what we’re dealing with right now.

So the topic of this talk is subjective standards. Back last summer, I was on a, one of these Zoom meetings with a bunch of people. There was an attorney, mayors and consultants from both sides. And I started looking at who got notification letters and who did not. So I asked the attorney, I said, “I’m noticing that people who are closest to this problem, not all of them got notification letters, but people who are farther away did.”

I said, “Can you can tell me what the criteria was for sending letters to residents?” Yeah, and he kind of hemmed and hawed, he said, “Well, we have kind of subjective standards.” And I said, “Well, I’ve been on standards committees most of my life, and usually there’s a, you know, glossary at the beginning of any document. But I’ve never seen the term subjective standards, could you define that for me?” And he said, “Well, are you trying to be cute or funny?” I said, “No.” I said, “No, I’ve driven through your town, I’ve looked at the architecture, I absolutely believe that you’re telling the truth. And you do have subjective standards. I just want to know how they’re defined, how somebody files a claim, and how that claim is then adjudicated, if there’s subjective standards, and who that arbiter is.”

And at that point, you know, I looked at the mayor’s part of the screen, and his face was getting pretty unhappy. So I just kind of dropped it. But, and then I thought, well, this is no different from vapor intrusion. We have lots of states, lots of documents, standards that differ by five orders of magnitude. And it’s definitely a problem.

So the first thing we’re gonna talk about is, you know, these inconsistent action thresholds. If you look at these chemicals, and these are kind of the top four chemicals that are involved with vapor intrusion, and are the ones that we see over and over again, there are significant differences. And these are…these chemical concentrations are what determine the actions to mitigate or not to mitigate. So if you look at this table, what you’re gonna see is the standards for carbon for TCE are two orders of magnitude different. The standards for carbon TET are four orders of magnitude different. And this is determining how a lot of money is being spent.

And you know, I’m not the first person to call this out, Bart Eklund and Rich Rego did some work on it a couple of years ago. And I actually used their numbers when I first put this chart together, and I figured, “You know what, I better go back and check on that.” And we rechecked all the most recent versions of these guidance documents, and we found out that most of them have changed again in the last two years. So we’re definitely chasing a moving target, and for sure it’s a problem.

So, the next one is inconsistent values in soil gas screening levels. And different states and the EPA(VISL) are all pretty much different. California is by far the most conservative. In fact, you see that green bar there, that little tiny one, we actually had to magnify that four times when we created the graphic, because the green line just kind of blended in with the baseline of zero. And the same thing holds true for indoor air levels. You can look at California, Virginia, North Carolina, all these are particularly different. And the weird thing about some of these California standards, you have businesses that are based in California, they’re based on Western part of the coast of this country. And that’s where their corporate headquarters are, so they adopt the standard of that state.

I had a large box of coffee store, and they had a particular threshold in order to take occupancy of a building in New Jersey, while there was 3 different dry cleaners within a few 100 yards. And the background outside was eight micrograms, and their requirement was three. So the only way to make that real estate deal work was to test it on Sunday when all three were shut down. But that’s not really representative of reality during the week. So again, but the one thing, the one thing that is constant throughout the entire part of this equation, is the human body. Your body doesn’t know whether it’s in California, Texas, or New Jersey, your genetics are exactly the same. And your DNA replication that’s subject to cancer risks is exactly the same. So, how do we solve this problem?

So, let’s get back to the beginning. And let’s talk about where the whole thing actually started. And I was very fortunate, I was able to be on this site as a technical consultant in 1985. It was the first, EPA’s first vapor intrusion site ever. In fact, it was called a fume site because most of the concentrations of indoor air that we were dealing with were well into the parts per million. It was thought that this fume problem or vapor intrusion was caused because of concentration gradients. Which that means that there was a high concentration of a chemical in the soil, below the slab, and it kind of diffuses through the slab as a diffusive barrier, and creates an indoor air problem. So my first day on site, I asked to see all the data from the previous analysis, and there was about 30 homes.

And I start going through the last months of daily data. And I realized that this data, the concentrations are going up and down every day. And one thing was ragingly apparent, and that was that concentration gradient diffusion was not the primary driving factor. I started thinking about what was. And I was driving to the site one morning, and there was this steam coming up from a cold morning up through the car system, there was a crack and a cave. And at that point, it hit me that these things are pressure driven. There’s a bunch of variables. I went to the Kentucky Western University in the Meteorological Department, it was headed up by a guy by the name I believe of Nick Crawford.

And I asked him if he had weather data, he said he did, but you can’t take it off the floor. The long short of it is, I wound up hand copying all the weather data from the previous six weeks along with the analytical data. And what I noticed was that there was definite trends, and I was able to write a predictive equation based on the data which would accurately predict this, what caused vapor intrusion.

So now, we kind of have the origins of what happened. Following on the heels of that was the first radon research projects, which I was also fortunate enough to be a part of. And this is where the rope starts becoming unafraid. A lot of mitigations, the mitigation systems are deemed successful in their performance not based on indoor air concentrations, but based on pressure differentials between the sub slab and in the building. And a lot of the foundational metric and value is, metric is pressure differential and the value in most documents is 0.02 inches of water column. So I’m gonna talk about where that started, how it got off track right now.

We were in a house on the south side of Columbus, Ohio, myself and some other investigators. And there’s a building physicist named Terry Brennan, who is heading up that component of the project. And Gene Fisher was the radiation person, radiation programs and EPA. He came out and he said, “Hey, Terry, we’re trying to get some general guidelines together. What do you think is a reasonable pressure differential, so we can say if we have this pressure differential, we’re not gonna have radon in the house?” And Terry said, “Well, it’s probably 0.01 inches of water column would be good. If we had that, you know, we’re not gonna get radon coming into the house.” And I said, “Terry, you know what, there’s one problem with this.” And do you ever go through life and you make statements and you wish you could reel them back? Well, for me, this is one of those.

And I said, “Well, with this particular instrument,” right here and you’re seeing it up on your screen, “It has a manual zeroing wheel. And when it says zero, we don’t know whether we’re closer to 0.01 negative or 0.01 positive.” And Terry said, “Well, then we better make it 0.02.” And Gene Fisher wrote that down, and it became lore. And it’s spread throughout radon and vapor intrusion world. And the reality is, that 0.02 came because there was a specific equipment budget for that project. And Hilti drills were by far the most reliable, they shipped better than any other drill. So we spent the money on Hilti’s, and there wasn’t enough money left to buy better micro manometers. And that’s why we have 0.02.

So after that research project, the industry was quiet for a long time. We had the Endicott site, the New Jersey guidance, ITRC. But in 2007 there was something critical that happened, and that was the Boyd Wertz study with Sunquist. It was a group of homes in Endicott, New York. And that was the first site where there was published data, data logging on pressure differentials. And what we found out, or what Boyd found out was that, that even with the mitigation system on there was a pressure differential range below the slab that went anywhere from a negative 0.158 to a positive 0.056, which meant the range was 0.211. That was the total range, which is almost a quarter of an inch.

Now, if you think about it, there’s an operational mitigation system that varies a quarter of an inch of vacuum. That’s pretty big. But the wrap up to the whole study was, and what they’ve concluded, and why this is very important was that if you could maintain a minimum nominal pressure differential of 0.004 inches or 1 pascal under the slab at the outer extent of the negative pressure field, then vapor intrusion would in fact be mitigated. That that is a key discovery. It’s kind of a watershed component in this industry, and what I’m gonna talk about moving forward. When you design a mitigation system, your target is the state guidance in that particular state. And when there is no state guidance, you can kind of flip back to the ITRC, or you talk to that regulator and say, “Well, I would like to use this state’s guidance for this project. And here’s why. And will you accept that?”

But these guidance documents are different, they’re not harmonized. The reason I was on the last ITRC committee was an attempt to harmonize some of these things. So standards are not so fractured as we move from state to state. Right now, not all states have VI guidance. There’s some states that even if they barely referenced some other state in a throwaway line, or they say, you know, we’ll track even with ITRC, we included that they did have guidance. And then the ones that are in orange don’t have any guidance at all. So anybody can do whatever they want, design anything they want and put it in. And as long as they make some case that it’s functioning under some rules that they themselves just set up, and maybe agreed on with a case by case basis with the regulator, then that’s okay in that site.

You can see why long-term liability then becomes a problem. So if we’re using pressure differentials as a metric, these guidances are, again, as diverse as the states are. New Jersey, Wisconsin and Georgia, Illinois, they’re all around point 0.004 inches of water column, 1 pascal. They kind of took their direction from the Wertz study. Other states have varying pressure differentials. Some of them have a summertime one and a wintertime one, thinking that if it’s over depressurized in the summertime then it should work in the wintertime.

California is different from everybody else. They have a pressure differentials standard of point 0.016 to 0.040, which is quarter 10 pascals, 10 times more than New Jersey in order of magnitude. Which creates an entire host of unintended consequences, including mining methane from outside the footprint, a total waste of energy. California requires carbon filtering. So you’re buying carbon, which comes from harvesting coconuts in the South Pacific. It’s just a mess and a half, and it really needs to have a total think through of the process, and some solutions that involve controlling pressure differentials.

There’s been a lot of talk and technical papers recently about using airflow as a metric. What we know is airflow is highly variable, and the main variables are the leakage around the foundation, the leakage into sub slab, the permeability of the soil. Which is, you know, how far do you extend that vacuum through the sub slab fill house? And then you have the other component, which most of these buildings that we deal with are manufacturing buildings. And they have fume hoods that kick on to vent either excessive heat from manufacturing, or chemicals that are involved with manufacturing. We mitigated one building where they made cleaning supplies for residences, and you know, there’s definitely caustic gases that were going up through a fume hood, and that fume hood kicks on, and all of a sudden the pressure differentials in the building is significantly different. And that’s pretty representative of manufacturing world, because there’s huge blowers, several thousand CFM, and they kick on kind of actuated by need.

So what we found out is we, through our sister company Vapor Dynamics, which makes the Vapor Guardian 5500 which can not only monitor all these functions but they can control the pressure differential below the slab. And that can be dialed into any amount they want. This particular site here was in Michigan, Matt Williams, from Michigan Eagle calls dynamic controls cruise control for vapor intrusion systems. And I think that’s kind of a good way to put it for people who are not necessarily technical. But basically, there’s a sensor that’s embedded below the slab, you dial in or type in the pressure differential that you want the blower to create, and it keeps it a flat, even lying.

This is when they had this polar vortex a year or so ago, and the temperature went down to negative 13, below zero. You can see the pressure across the slab was held even by the control mechanism. But there is high variability in airflow that was coming out from underneath that building while that pressure differential is maintained. So over a 67 degree Fahrenheit temperature change, the airflow varied 97.9%. So that is not a really a consistent metric that you could put a number to. And then here’s another site where we didn’t control the fan speed on dynamic controls. And the net of this is you can see the airflow is in the purple line, and the temperature is in the red line. And when there was a…when temperature difference was over 100%, what we had was a 200% difference in airflow.

So who picks what value actually works? And how do you set it up with a consultant? And how do you know where the airflow is coming from? Because based on the leakage around foundations and cracks and buildings and slabs that shrink because it’s cold in the wintertime, you actually don’t know where the source of airflow is without a very complex tracer gas study to tell you where that’s coming from. So again, there is another piece of variability that’s being introduced to the puzzle.

The next part of it is new construction and new construction standards. EPA put out some stuff for radon new construction in the late ’90s. There is the NAVFAC document which was authored here at clean vapor through Patel, and is kind of what the Navy puts out for all their sites where they’re building new buildings. There’s a CC 1,000 soil gas which was developed by the radon guys and myself, and ANCR was on that panel. And that’s a great cookbook, and it tells kind of how to build an efficient vapor intrusion mitigation system that I believe will function passively under a variety of conditions. But then again, there’s a 60 different components in that document that have to be met for that standard.

Now, there’s other states that have standards for new construction. And you kind of have to blend that whole thing together when you’re doing your design and making sure that your performance metrics meet those design requirements. Things you wanna be thinking about most, new construction requirements. It’s a crushed stone plenum. There’s a low profile event thing, there’s plenum boxes like you see there, which are collectors in the center of a big room. There’s embedded test ports. You can see there, there’s the picture of…next to that low-profile, you can see the test port pot, which comes up through the slab. But we do at clean vapor as we have a probe and tube system that goes into crushed stone.

And instead of having test pots all over the floor that we can’t get to later after your clients moved in, we bring all that tubing up to a centralized panel. And that way, if you wanna measure the soil gas concentrations below the slab or your pressure differentials, you just go to the panel and you measure everything, and you don’t have to bug the client. It’s a pretty good way of doing it. And then after that engineered system has all been installed in the subgrade, your vapor barrier material can go down on top of that.

So there’s the current way of doing things, and there’s the antiquated way of doing things. The guidance from the 90s kind of says, and it’s all adapted from radon that you wanna have 1 riser per 1,500 square foot, and there’s a whole cluster of risers coming up in that picture right there. It’s not really representative of what’s going on. What’s kind of leading the way right now, and where the technology is, is that you have designed systems that are based on the square footage of the building, slab segment frequencies, the grade of stone, the thickness of stone, and you kind of bring all these risers together, and you control the entire area. Not from one riser, but not from multiple publicity of risers, but from a single riser.

There’s a case study of a school in New Jersey. The architect put one 3-inch riser per every 1,500 square feet or 1,600 square feet, which totaled 13 risers. I got the plan. Doug Brooks in our office looked at it, and we were able to cut this thing down to one six-inch riser. We went back to the GC, said, hey, this will work just as well as the other thing. They were happy they didn’t have to perforate the roof like Swiss cheese for these venting pipes. And on top of that we were able to save them $25,000. So all the way around, a good deal.

So what you’re gonna learn from this webinar and learn science, and Jordan has some great information coming up, is that not all vapor barriers are created equal. There’s a wide variety of materials with different purposes and different applications. And when you’re designing a system, you really need to know what the physical properties and benefits are of these vapor barriers. You start out first of all, you wanna understand the difference between a vapor barrier and a vapor retarder. Generally, vapor barriers were designed to keep out moisture. And they’re graded by the American Concrete Institute, I believe. And rule of thumb is, anything that’s less than 10 mils polyethylene polyolefin is a vapor retarder, is designed to keep out moisture, and there’s a moisture Permian scale for grading these things.

Anything over 10 mils is considered a good vapor barrier, but it’s not really a vapor barrier for vapor and chemical vapor intrusion, it’s a vapor barrier for keeping out moisture. Once you get above 15 mils, you start getting into the actual vapor barrier. Now keep in mind that we’re talking about apples and oranges here. Apples being moisture, orange is being chemical vapor intrusion. Chemical vapor intrusion is what we’re talking about today. Most failures in vapor systems that are installed are tape vapor barrier systems. And that’s because we as engineers understand the purpose of the tape, how it’s to be put down. But the reality is, these things are estimated by construction companies, with an estimator sitting in an office with a program, and they’re installed by labor guys who don’t understand why they’re installing something, haven’t been trained to install it properly, and nor do they have an investment in the outcome.

So it’s critical and most of the leakage and most of the failure takes place in this taping process, either taping the sheets themselves together, taping off penetrations, and most of the leakage occurs on the outer wall. They don’t get these things stuck to the outer wall gas tight, they pour the concrete, the concrete comes late, it’s wet, it shrinks, and you get this gap at the outer part of the slab where it needs the stem wall, it pulls the moisture barrier back or the vapor barrier that’s taped back from the wall, and all your soil gas is find your way to the seams, and they come into buildings. Or if you have an active system, that’s your leakage pathway, but you can’t get to it usually to seal it because now it’s behind a finished wall or something. You see the MonoShield being put down here. It’s a film that’s designed to be joined, spray-applied because it’s got kind of a rough coat on the edge of the scene. And here it adheres.

Well, even if you spray apply to other films, these films are slippery, and from a finished component, because they’re so smooth and they’re so exact, there’s not pores for this material to sink in and be adhered to. Whereas the MonoShield is designed specifically to meet that joining function. Here are some rollout event below the slab, there’s crushed stone, it looks like it’s a 57 stone or greater. Which is awesome because that means there’s 25% to 30% voids within the crushed stone. It’s critical that the vapor barriers be put in as installed. And if there’s any amendments out in the field, they are noted in the [inaudible 00:31:33.928]. And if that’s been done properly, then you’re all set to put the concrete down.

So here’s some performance analysis from two buildings that I worked on. The first one was a taped seam project, where we were called into the…by the GC because he just thought the piping below the slab looked wrong. And he didn’t think that the diameters are right, he knew enough about it. They called us, we wound up engineering the subgrade but really didn’t have a lot of say with how the rest of it was gonna be installed because there was piping agreements and the contracts were already set.

So in that particular building, one riser per 2,700 square feet, there were 118 watt blowers, they were activated. The pressure differential that it created below the slab was point 0.792. Pretty high vacuum pressure differential. But keep in mind there is 14 blowers exhausting 272 CFM out of that building. And that’s, in the wintertime that’s warm air, in the summertime that’s conditioned air. And the cost of running the blowers alone on a 14-cent per kilowatt hour was $450.

The spray-applied vapor barrier on the other hand, we were able to get to 24,000-square-foot building on one riser. The average pressure differential below the slab was 1.8. That particular blower, by the way, generated 2.7 inches of vacuum. It took 125 watts, which meant on the energy cost it was $63. And we only exhausted 49.5 CFM. And that’s not for the whole building. This is based on making the scale the same, where we’re talking about the cost per 10,000-square-foot of floor space. And you can see that’s noted in the lower left hand window there.

So here’s an energy analysis on it. Again, I kind of went over that in the previous slide. There’s, as you can see, per 10,000 square feet, if you have an active system, there is a significant difference. And the efficiency of spray-applied vapor barrier systems, whether that’s spray-applied seams or the entire barrier spray-applied. So that savings is an annual savings of $1,000 per 10,000 square feet of floor space.

So most of these buildings that are constructed, there’s a 20-year note on them. And if you look at that graph right there, without question, the better vapor barrier, the more it is to install. However, if you look at the energy penalties associated with active systems, what you’re gonna find out is that better vapor barrier with the gas tight seams will pay for itself in about 9 or 10 years. And then after that, you’re in the pure positive cash. And that goes on for the entire rest of the building.

Not long ago we mitigated a building which was a bank building that was built…was 110 years old, and it was in a high water table area. And we core through the slab, we found a fill paper in asfol [SP], probably brushed or broomed on layer. But that basement 110 years later was bone dry. And what that taught me was somebody was thinking ahead, and the investment of that vapor barrier paid off again and again and again and again, because that space was usable, it was not impacted by water or moisture at all. So, pretty significant stuff that we’re looking at right here.

The next part of this, and that’s the last part before Jordan takes over, is inconsistent OM&M guidance. There’s only 16 states in the entire country that have specifications for how the systems are handled once they’re installed. And the reality is that this is where the whole industry falls down. Most of the time the systems get installed, you exchange the closure or the commissioning report for a check, the consultant is paid. And then the consultant chases the property owner around to be able to do OM&M measurements. We really don’t have a lot of idea about how well the people are protected, since many of these systems become orphaned.

But there are some states that are headed in the right direction. When the system goes active, New Jersey requires quarterly measurements on the sub slab and system performance for the first year in annual inspections, the year after, that’s becoming increasingly more standardized. Massachusetts has telemetry, which is not only telemetry out, does this work? You know, does it not work? But you’re actually looking at performance numbers, data, logging, those things, and tying the values back into fault notifications, which are electronic. So that is a good step in the right direction. And that is increasingly where we’re seeing our RPs and our business unit owners moving to.

They know that this liability thing is a huge problem. And they’re trying to figure out how to deal with it on the front end. And so basically, there’s a couple of different levels of quality when you deal with this. The basic thing that’s mentioned in every guidance document is audio visual alarm. And this is an example of one, it’s just the Magnehelic gauge, straight vacuum gauge tied to a red light, green light and in enunciator. There’s an alarm, there’s a label, there’s somebody to call. Somebody has to walk over there, and physically hit that on/off switch and know that there’s a problem, that that switch doesn’t go off by itself, somebody needs to be aware that there’s a problem. And there’s usually some documentation or some stickers on there. And if this light comes on, or this alarm comes on, call this number.

The next level of protection is telemetry, and that’s direct read out. That’s not controlling fans, it’s nothing like that. The instrument that our sister company produced, the Vapor Guardian 600, what that does is in addition to tracking all the weather variables, the outside temperature, wind speed, barometer, dew point, all the things that affect air density and vapor intrusion, it can look at any six metrics you want, meaning sub-slab vacuum, applied vacuum, the airflow, power that the motor is using. And you can set the alarm thresholds wherever you want them, you do that on the computer.

So if you’re in a state, and your standard is point 0.008, and you wanna know about it when it gets close to 0.01 so you can do something about it or know that there’s gonna be an event before a heart alarm, you can just program that in yourself. All the data is recorded hourly. It can be accessed by the consultant or the owner. And in fact, all those crafts that you saw in previous slides, they all came off these Vapor Guardian 5500s and Vapor Guardian 600s. Because you as the consultant can just jump in and look at the data whenever you want. There’s some states where the RPs and the state are shared on the same email notifications at the same threshold. That way they know what’s going on, and a lot of state sites that have gone into bankruptcy or receivership, and the government has taken the financial costs for mitigating. They want to be aware of this too. So it keeps everybody in the loop. It keeps all the cards faced up on the table. Nobody has an opportunity to hide anything. But also if there is a fault, people get to deal with it pretty much immediately.

The workhorse product which is being used pretty much throughout industry right now, on large mitigation sites is the Vapor Guardian 5500. This looks at all the same weather metrics as the Vapor Guardian 600. The main difference here is this takes those embedded sensors that would normally be measuring pressure differential, and applies it to a dual use, where if you’re in a certain state, and your threshold is 008 inches of water column below the slab, you just program this to run at 008. And if there’s a problem, and you need to change the set point, or anything like that, it’s control in and control out. So I have a client, by the time we’re all done they may actually have 80 fans at that building. And I can change any one of them at any point I want. Every hour of data is recorded, there’s fault notifications. And the entire OM&M is really on autopilot.

Anything goes wrong at any point, we know right away when we’ve met the requirements of the state, we can meet the requirements of any state just by changing the set points up and down, and we have a full record of what happened. And even more importantly, we’ll know what happened in liability, which is the key thing. One of the driving factors in developing this technology was we fixed a daycare several years ago, it changed hands and the daycare was one module of more than a million square foot shopping center. And we went back a year later to do the OM&M, and of course it was several hours away drive, and we thought we had all the keys for all the buildings. It turns out that one place we didn’t have the keys was where the alarm center was.

So when we finally got back there, I got a call saying, “Hey, Tom, it turns out we have a problem. The fan for the daycare is not working.” And I’m like, “Okay, so what about the enunciator?” They said, “Well, that shut off.” I said, “Okay.” So I called the owner of the building and I said, “How long is the fan at the daycare been off?” “So, I don’t know.” I said, “What, do you think it’s a month? Do you think it’s 11 months? I mean, what do you…any guesses?” He said, “I really don’t know at all.” I said, “Well, who turned it off? I mean, somebody had to go in there who had a key to that utility space and turn off that alarm. “He said, “I don’t have any idea. This is the first time hearing about it.” And I said, “Well, do you know what the long term liability is for a child that’s in a daycare in New Jersey to sue a building owner?” And he said, “No.”

I said, “Well, I do. And that means that there’s a problem here.” And that is really where the origin of electronic monitoring and vapor and intrusions systems came from. So we have a lot of standards and things are all over the map. There’s a lot of variability in the industry. Consultants talk about it when we’re at these meetings, practitioners do, regulators do. But if we don’t get together as an industry, as regulators and standardize this, this is exactly what we’re looking at, and it’s not gonna be fun.

So, what is the solution? There’s three things I think we can do to solve this problem. One is, we get together with the toxic ecologists, and we set mitigation criteria for performance for existing buildings. That would include inspections, OM&M programs for new construction, consistent plan reviews, inspections during construction, quarterly performance for the first year, annually thereafter. And then integrate telemetric monitoring with active fault notification and data recording. That would knock out a lot of the long-term liability. So if we can do that, that’s what our future is looking on. With that, I’m gonna turn it over to Jordan Knight, and she’s going to tell us about vapor barrier materials.

Jordan: Good afternoon, everyone. I just wanna take a quick moment to say thank you to Tom Hatton and his team at Clean Vapor. It’s been just a really enjoyable process working with him in developing this presentation and just having him share his expertise. I’m excited to build on some of the points that he brought up related to best practices for vapor intrusion mitigation design development. You know, as we just heard, Tom highlighted the importance of incorporating contaminant vapor barriers into his overall design process.

And so today, I’m going to share several advanced vapor barrier technologies that can be implemented into a site’s vapor mitigation plan to help minimize those risks that often come with contaminated site root development. So for those of you that may not be familiar with Land Science, we are a division of the global remediation company, REGENESIS. Our overall mission is to simplify the environmental remediation and the vapor intrusion mitigation process. And that’s done by manufacturing cutting edge, cost efficient technology solutions, and by providing exemplary technical service and support.

Our corporate headquarters, we were founded in the early ’90s and operates in San Clemente, California. I will say, you know, despite a very unprecedented and challenging year for all of us due to the impacts of COVID-19, REGENESIS and Land Science have been very fortunate to still achieve significant growth. And that has led us to expand our operations and manufacturing capabilities into a state-of-the-art production facility just outside of Nashville, Tennessee. So, Land Science, our entire focus is to manufacture and implement the absolute best vapor barrier solutions in the environmental marketplace. And this expansion uniquely positions us to be able to do that.

So when you’re working with our team that Land Science, you can expect a tailored solution that meets your project goals. Because we offer a full suite of vapor barrier technologies, and each of these are designed for a wide range of sight conditions, and are backed by our industry leading warranties. Additionally, our vapor barrier technologies are installed with a very high level of quality through our certified applicator network. We also offer hands-on vapor mitigation system design support, as well as an inspector training program for the engineering and consulting community.

Land Science we’ve been a recognized industry-leading provider of spray-applied composite vapor intrusion barrier technologies since 2007. After years of research and development, Land Science has brought two major vapor barrier material advancements to the marketplace in 2019. And that is with our metalized film geomembranes, and our nitrile-advanced asphalt latex. These two material innovations increase the constructability of our vapor barrier systems, but most importantly, they increase the chemical resistance and performance of our vapor barrier technologies. You know, as Tom mentioned, long-term performance against contaminant vapor diffusion is really what the industry expects, and what evolving regulatory standards require. And we found that by incorporating metalized foam within our barrier sheet materials, it provided orders of magnitude, greater resistivity to contaminant vapor diffusion.

So, as you can see here from this normalized comparative analysis of our metalized film base layer, or TerraBase, versus a 10 mil HDPE base sheet, the reinforced metalized film layer was over 140 times more effective at limiting gas diffusion of TCE vapors when subjected to identical testing conditions. So that base layer with metalized film was two orders of magnitude more resistant to TCE than that HDPE base layer. So, the other significant material advancement that I referenced is our nitrile-advanced asphalt latex. Now, traditional spray-applied vapor barriers, including our own legacy technologies, they were born from the waterproofing industry and considered good enough for vapor intrusion mitigation.

But really, there’s no longer a need to settle for good enough. Land Science, we now manufacture a proprietary nitrile-advanced spray-applied material that is formulated specifically for contaminant vapor intrusion mitigation. So by adding nitrile into our spray-applied formulation, we saw up to an order of magnitude greater resistivity to TCE vapor diffusion versus the older generic spray-applied technologies, which is represented by the red line in this graph. So from a mitigation system design standpoint, you know, this translates into a more reliable, long-term mitigation solution, particularly at any vapor barrier system weak points. And that’s something that Tom had reiterated, was, you know, those seams and utility penetrations around your building parameters, you know those locations now offer up to 10 times more resistivity to vapor intrusion with that nitrile-advanced asphalt latex.

So from the two material innovations of metalized film geomembranes and nitrile-advanced asphalt latex, we introduced three spray-applied vapor barrier technologies to the marketplace, TerraShield, Nitrile-Seal and MonoShield, which have been rapidly adopted by the industry for contaminant vapor mitigation. Our TerraShield vapor barrier system, that is a 3-layer composite spray-applied membrane which consists of a 25-mil, reinforced metalized film base layer or TerraBase. Followed by a 40-mil application of our nitrile-advanced asphalt latex, known as our Nitra-Core. And then it’s topped with the Land Science protection fabric. And that’s to help withstand the next phases of construction, whether that’s rebar placement or foot traffic to anticipate the concrete.

TerraShield offers the highest level of protection in the industry, and it has been installed and approved by multiple regulatory agencies across North America. TerraShield is intended for sites needing maximum protection from vapor intrusion, such as this federal site and California. In the background of this photo you can see the TerraBase metalized foam layer being rolled out on the subgrade material, and then the 40-mil application of Nitra-Core across the majority of the building footprint.

Nitra-Seal is Land Science’s most cost efficient composite spray-applied barrier system. The components of this barrier system include our 23-mil Nitra-Base layer. And that is comprised of a polyethylene with an underside geotextile sheet layer, followed by a 40-mil application of the Nitra-Core. And then an 18-mil land science bond layer, which is an HDPE geotextile protection layer. So you can see the Nitra-Seal system installation coming to completion at this ecommerce distribution facility in the greater Nashville area. At this stage in the project, the Nitra-Base and the Nitra-Core had been deployed. And the certified applicator was sealing the seams of the Land Science firm layer.

So, the last system I’ll be sharing today is our MonoShield system. This is a single layer, 30-mil geomembrane comprised of reinforced metalized film, a polyester reinforced bread, and encapsulated by layers of polyethylene. And this also has an underside geotextile fabric. So this single layer membrane is sealed using the nitrile-advanced asphalt latex, our Nitra-Core, at all seams, penetrations and perimeters. There’s a proven market need for preemptive vapor intrusion mitigation as what you might characterize as a low risk site. This market was traditionally served by thin metal plastic sheets like Tom described earlier. Those can range anywhere from 6 to maybe up to 20-mil in thickness. And those generally rely on tape to seal up their seams.

However, MonoShield is an ideal candidate for these scenarios for preemptive mitigation. The spray-applied seams offer superior speed of installation as compared to other single layer tape seams. Just for reference, on a slab on grade large scale warehouse application, similar to the site condition you see on the right. You know, our certified applicators can install the MonoShield system twice as fast as a 20-mil tape system. That’s installed by site contractors. The MonoShield barrier also provides substantially greater durability with that underside geotextile and that polyester reinforced grid that is embedded within the membrane.

Now, each of our vapor barrier technologies that I’ve described today, they all offer a high level of constructability which really is a crucial component of the vapor barrier evaluation process. The spray-applied nature of our systems and our certified applicator experience makes for an efficient application out in the field. With the reinforced grades, the underside geotextiles or sheet layers are designed for system durability. And then the multi-layer composite systems offer redundancy necessary to withstand the rigors of construction.

Quality control, that is a major facet of any vapor mitigation system installation. For all spray-applied vapor barriers there should be many layers of quality control and quality assurance in place just to confirm that the system is installed properly. So, this really starts with the installation being completed by a certified applicator or the manufacturer. You know, that applicator is gonna conduct thickness verification of the spray-applied layer, you know confirming it’s being sprayed at the specified thickness. And then they’re also going to perform smoke testing. And that’s to seal up any pinhole leaks that wouldn’t be identified from a general visual inspection.

Oftentimes, there’s gonna be a third-party inspector on site, really designed to oversee and document the installation and the quality control measures being conducted by the certified applicator. And so this may also include being present, and conducting a pre-pour inspection of the membrane to identify any potential damage or repairs that may be needed prior to concrete placement.

So the main takeaways I would like to leave you guys all with today are that nitrile-advanced asphalt latex and metalized film sheet goods, they represent major advancements in vapor intrusion mitigation materials. I think we all know that every site will present its own set of unique challenges. And with vapor mitigation, there really isn’t one size fits all. There are a variety of vapor barrier technologies available for new construction. And when evaluating them for your site, you know, chemical resistance, constructability, and quality control are all important criteria to consider. So if you guys have any questions, please let us know. We really appreciate you all for participating today.

Dane: All right, thank you very much, Jordan. So yeah, that concludes the formal section of our presentation. At this point, we’d like to shift into the question and answer portion of the webcast. Before we do this, just a couple of quick reminders. First, you will receive a follow-up email with a brief survey. We really appreciate your feedback, so please take a minute to let us know how we did it. And also, after the webinar, you’ll receive a link to the recording as soon as it’s available.

All right, so let’s circle back to the questions here. First question is a question for Tom. And it is, do you take the same approach in your design process when designing a passive system versus an active system for new construction? And do you always include a contaminant vapor barrier in your design?

Tom: Well, that’s a good question. And it’s kind of a two-part question, so it’s gonna get a two-part answer. Our primary goal in every system that we design is efficiency and venting. We look at all the components, the building the gravel, size the pipe, and just figure out from a physics standpoint, what is the most efficient vapor venting system?

And the hopes are, that is, it would never have to go active. But if it did have to go active, it would be highly effective with a low voltage motor. Now, the second part of the answer is, if we’re asked to design a radon system, we may go and there’s no chemical contaminants, we may use a sheet film to do that, because we cannot get these developers sold on a more expensive vapor barrier. Now, we’re very effective in doing that, but it’s not the case all the time.

Dane: All right. Thanks very much, Tom. So here’s another question. And this is for Jordan. And it is, does Land Science offer any venting technologies to be used in conjunction with the barriers?

Jordan: Yeah, that’s a great question. I did not present on that element today, but we absolutely do. Land Science offers a low-profile paper collection system called TerraVent. And this is designed to be used in combination with our barrier technologies. And it can be used in lieu of slotted PVC, to reduce overall installation costs of the venting system.

Dane: Okay, thanks very much, Jordan. All right, so we are just about out of time. We have time for maybe one more question coming in here. This one is for Tom. And it is, is there anything that industry professionals and attorneys are doing to curb the long-term liability of these subjective standards?

Tom: Yeah, I’m glad that you asked that. That’s a great question. About five years ago, we really started seeing a need to stop this rope from fragging and becoming more diverse. And about a year and a half ago, myself and several other industry professionals got together, we put together the Association of Vapor Intrusion Professionals or AVIP.

And basically what this is, is the…one of the focuses is to standardize the industry. And there’s multiple segments, then we’ll focus on mitigation. Others will be vapor barrier technology, new construction practices, and long-term liability, loss control on the legal side of things, and just bring together the entire spectrum of what happens. And instead of having haphazard vapor barrier installations, there’s gonna be certification on the mitigation side of this, as well as the design side of it. So we can put this all together. It’s very exciting. I’m looking forward to it.

And basically, anybody who heard this webinar, please come to the website. And, the temporary one is avip.memberclicks.net. And that will come right in, and we’re optimistic about our future. And we’re welcoming everybody to join and participate, because there’s plenty of areas to participate, and we welcome your expertise.

Dane: All right. Thank you very much, Tom. Yeah, so that is gonna be the end of our chat questions. If we did not get to your question, someone will make an effort to follow up with you. For more information about vapor mitigation technologies from Clean Vapor LLC, you can visit cleanvapor.com. If you’d like to learn more about vapor intrusion solutions from Land Science, please visit landsciencetech.com. Thanks again very much to Tom Hatton and Jordan Knight. And thanks to everyone who could join us. Have a great day.

Dane: So we are running out of time. So that is going to be the end of our chat questions. If we did not get to your question, someone will make an effort to follow up with you. For more information about vapor mitigation technologies from Clean Vapor LLC, you can visit cleanvapor.com. If you’d like to learn more about vapor intrusion solutions from Land Science, please visit landsciencetech.com. Thanks again very much to Tom Hatton and Jordan Knight. And thanks to everyone who could join us. Have a great day.