 So we're going to get started with our breakout session, session B, where we're going to be talking about assessment methods. And to start off, we're going to be having Shannon Suggs from the North Dakota Department of Environmental Quality, talking about the North Dakota risk-based corrective action in a case study form. So Shannon Suggs has a master's in geology and an undergraduate degree in environmental geosciences in geology. Shannon has 15 years of experience in the environmental field. She currently works with the Ground Water Protection Program of the North Dakota Department of Environmental Quality, where she is the Source Water Protection Coordinator and lead of the North Dakota Rebecca's program, overseeing remediation sites and other projects. So with that, I'm going to pass it over to Shannon. We're going to get things rolling. Hi, so my name is Shannon Suggs. I work for the North Dakota Department of Environmental Quality. Today, I'm going to be talking about the North Dakota Risk-Based Corrective Action Program, or Rebecca, as we call it, ND Rebecca. And I will also do a case study. So first, I'm going to give a brief overview of Rebecca and then dive into the case study for Rebecca. So first off, I'm going to cover some of our interconnected programs that we have at the NDDQ. And can you guys hear me okay or do I need to be closer to the mic? Good? Okay. So the NDDQ's mission is to conserve and protect the quality of North Dakota's air, land and water resources following science and the law. These three interconnected programs that we have listed here, Rebecca, the EQRF and the VRA, helped the NDDQ to achieve this mission for contaminated sites in North Dakota. So Rebecca, or the Risk-Based Corrective Action Program, is guidance adopted by the NDDQ on how to assess a contaminated site based on the risk the contamination poses to the human health and the environment. The EQRF is our Environmental Quality Restoration Fund. It's a source of funding through NDDQ for remedial actions or investigative actions on sites. And then the VRA is our Voluntary Response Actions. And that is undertaken by property owners, perspective owners, or other third party interests to address environmental contamination on a property. And I'll go into a little more in-depth on each of these programs just briefly. So first off, the Environmental Quality Restoration Fund. This fund has actually been in existence for a while, but it was limited in scope to addressing only emergency actions until Senate Bill 2070 passed in 2021. Amendments made to the EQRF in that SB 2070 bill included expansion to address non-emergency environmental contamination and increased funding to address larger projects. So we moved from emergency only to being able to address what we like to call maybe orphan sites or other sites that might need funding to help in remediation purposes. This bill also authorized the NDDQ to take action to compel a responsible party to initiate cleanup and allows the DEQ to seek cost reimbursement from responsible parties similar to like the federal Superfund. Some people are calling this kind of a mini Superfund, and it is similar in some ways, but it is a state fund. So the Voluntary Response Actions, which is another of the programs I mentioned, were also addressed under this bill. So since SB 2070 is passed, the NDDQ has been working on the North Dakota Administrative Code Article 33104. And those are the rules for managing the EQRF. So our Voluntary Response Actions. These amendments were also included under SB 2070. So Voluntary Response Actions, Liability Protection Procedures. This amended previous procedures that we had in place for release of liability procedures for properties that had contamination. So this is the new form for gaining liability protection on contaminated properties, and that's our Voluntary Response Actions. So the keyword in the VRA is voluntary. So there any voluntary action taken to address environmental contamination or address health hazards or risk of environmental contamination on a property. So VRAs are conducted when a property has identified or suspected environmental contamination, and this is to achieve the outcome of liability protection, improve property value, and reduce the risk to human health in the environment, which is one of our key drives. So this is a five-step process that you need to follow, and at the end of that five-step process, once you go through the entire Voluntary Response Action, you can receive a certificate of completion, and that certificate of completion is what serves as the liability protection for the contaminated site or the contamination identified in the process. And on to Rebecca. So Rebecca is a formal framework for decision-making for planning environmental remediation goals. So we've always had a risk-based process. This formalized the process for us. Rebecca has been developed out of ASTM E1739 standard, and that was published in 1995. So it has been around for quite a while. When that ASTM standard came out at the time, it brought about a fundamental paradigm shift in how remediation was treated in the remediation world. So we moved from the conventional approach prior to that of how much contamination can be removed to how much contamination can be safely left in place based on risk. So Rebecca outlines the framework for integrating the traditional remediation methods with a risk-based assessment aimed at data-driven, quick and consistent management decisions that can be used on a variety of contaminated sites. Rebecca helps to assess sites based on risk, allocate resources for maximum protection, and provide the appropriate level of oversight to move sites forward quickly. Our main goal with formalizing Rebecca is to streamline the process and make it more efficient. So for the ND Rebecca elements, you have site characterization, which is the where, risk assessment, which is the what, and risk management, which is the how. So ND Rebecca begins when a contaminated site is identified and any emergency actions have already been completed. It is an integrated process of the site characterization, the risk assessment, and the risk management. So site characterization describes the where. Data collection on a site will tell you where the contamination is. Site assessment of the site will tell you the pathways of exposure and where the receptors might be impacted. The risk assessment part determines the what. What is the risk to human health in the environment based on the site characterization of the contamination? What are the pathways of exposure, the receptors, and what is the appropriate target cleanup level? And then risk management answers the how. How will the site reach the target cleanup? Is it going to be through remediation methods, engineering controls, or institutional property management? So the conceptual site model in ND Rebecca is kind of the heart of the storytelling of the site. It can be the site characterization. All of that can be summed up in the conceptual site model or the CSM. The key elements of the CSM include a site map showing the property, the boundaries, the contaminations of concern, their source and release scenario, the spatial and temporal distribution of the COCs, contaminants of concerns, or the delineation of the contamination, the current and future land use of the contaminated sites, the media potentially impacted by the COCs, is there soil impacts, is there groundwater impacts, surface water, air, indoor air, the representative concentrations of the contaminant, what actions have been taken to date on the site, and then the exposure model or the EM. So the EM identifies the receptors, the exposure pathways, the comparison representative concentrations to the risk-based target levels or screening levels, and the routes of exposure under current and reasonable future land considerations. So under Rebecca, you're not just looking at the site as is, you're also looking at what the site could potentially be down the road. It might be zoned commercial industrial now, maybe in the future it'll be changed zoning to residential and suddenly you'll have a house or a daycare being built on that site. So you have to consider the reasonable future land property. And then the extent of contamination and complete evaluation of routes of exposure, not the property boundaries affect the extent of characterization, which means you follow and completely delineate all the contamination, whether it goes off boundary or not. All right, so the risk assessment. So under Andy Rebecca, there's essentially three tiers of the screening levels that will transfer into target levels once you get higher in the tier levels. So the risk assessment involves the use of the risk-based screening levels. That's our tier one. So the tier one levels, and these are for both residential and commercial identified properties, are based on the US EPA screening levels calculated with a target risk of one to the 10 to the negative fifth. We differ from EPA in that on our state level because EPA typically uses a 10 to the negative six for their target risk. We went a little less conservative on our state levels. We felt it was appropriate and we went to 10 to the negative fifth. And we retained a hazard portion to one, which is typical of EPA screening levels. So these are generic numbers. The tier one are your default basic generic numbers. They use default parameters in the groundwater RBSLs or the risk-based screening levels are based on the EPA's MCLs or maximum contaminant levels. The NDDAQ does have some state-specific RBSLs on certain contaminants such as TPH, total petroleum hydrocarbons and nitrates. The tier two specific site-specific target levels, and they switch to a site-specific target level in a tier two because you are using site-specific parameters on this level. So some of the parameters that you're going to use are calculated using the fate and transport parameters of the site. Specific soil types, maybe you have specific hydraulic conductivity for the site. Hydrogeology, if you have done more site-specific parameter work, that's where a tier two can come into play. So the tier two SSTLs use that site-specific data collected and the application of the fate and transport models. So NDDAQ-specific values may still apply at the tier two level. Actually, the site-specific values can apply across all three of the tiers. And I do want to mention tier three, which goes a little bit farther using the application of those fate and transport models, is very rarely used. Only on very complex sites will somebody probably go as far to use the tier three. So for risk evaluation, a site risk evaluation involves several considerations. The CSM of the site, including all the stuff that was involved in the CSM, the land use, the COCs, impact at media, the exposure model. They're all involved in the risk evaluation. And the risk evaluation is looking for the protection of your groundwater resources, your soil, your air, your surface water, and also your ecological resources. So if you're impacting animal health as well. Okay, so for the risk management part. So risk evaluation identifies the risk on the site. Risk management ensures that that identified risk is managed so that the conditions are going to be protective of that human health and the environment. So risk management on a site can include many options. You have your traditional remedial methods such as soil removal, groundwater remediation systems that can be used to achieve site stability. And then you can also use other methods, including engineering controls. And that could be a system that's in place. Say if you have vapor intrusion problems into a building and you have a vapor mitigation system, that would be an engineering control. Also the use of environmental covenants with institutional controls to manage risk on the site. Environmental covenants usually center around and are tied to the property. And it would be something such as you're not allowed to drill well on this property because of the groundwater contamination that's potentially there. So that was a very brief overview of ND Rebecca and some of our other programs that we have in NDQ. So I'm going to go into a case study to try to show the application of ND Rebecca to a site. This is the Tali right of way corridor. It's a railroad corridor. It's a historical site. This corridor has been active since 1905 with numerous activities, including coal sheds, a green elevator, mechanical garage was on site, bulk oil and fertilizer storage. So the current site consists of about 35 acres with assigned railroad lots. Lots are numbered one through 52. There have been as many as 19 leases on the property in the past. Currently, there's only seven of those leases that are active. And those are held by two different lease owners. CP or Canadian Pacific Railway, Sue Line Railroad is the owner of the right of way. So they hired a consultant to conduct an environmental site assessment or an essay of the corridor. Several recognized environmental conditions or wrecks were identified in the essay. And this led to further work on the site, including soil and groundwater sampling. So this is a brief overview of that conceptual site model and some of the information included in it again. So site information, including location, hydrology and geology, historical or existing land use restrictions. The COCs, the type and source of COCs and age of release, if possible, historical releases for the site. The media impacted sampling to characterize representative concentrations in the media. Any previous remedial activities that were done on the site. Then the exposure model, including the properties type, the current and future land use. Comparing the representative concentrations with either the risk based screening levels or the site specific target levels for the site. Assessing the pathways of exposures, the receptors such as water wells, surface water, routes of exposures such as ingestion, dermal contact, inhalation. So the CSM is a living document, we'll call it. It can be updated and should be updated as needed as new information might come in on a site. So this is kind of a sum above the Tali CSM. It's a Sioux line railroad corridor in Tali, Renville County. It sits on a site that's silty with one foot fill material on the surface. Currently there was no institutional controls or activity use limitations on the site. Connect to the contaminants of concern were petroleum and nitrate. From the former bulk or fuel storage area, there was a UST AST. And then there was the dry fertilizer loading and unloading areas. The media impacted on this site with soil and groundwater. And I'll show you a map in just a few seconds. So previous remedial activities, the UST and AST were removed. 1,000 cubic yards of soil removed near them. And this was near least 1376 and that was in 2012 on this site. So I'll kind of walk through a little bit of the exposure model. The siting is commercial industrial for current use. It's proposed to be that for future use as well. For the risk based screening level, the representative concentrations on site exceeded the tier one. So the representative concentrations were then compared against a calculated tier two SSTL for the site. So also on the map, the city obtains its water from Upper Surrey's Water District. There's no really receptors in the area. Some of the potential pathways included potential ingestion, dermal contact and inhalation of contaminated soil and or groundwater. And then the proposed institutional controls in the site to mitigate the pathways. So this map shows the tolly, rural corridor as well as the surrounding property. Some agricultural, there is some residential to the north. There is a landfill siting also adjacent to the property. But the quarter itself is outlined in yellow and showing the different. So the leases don't exactly coincide with the railroad lots. There's several that cover several lots. So soil sampling was completed in the identified recognized environmental condition areas in the soil results were compared with that. Andy Rebecca or tier one default levels for the industrial commercial site. Several exceedances were identified. The primary area of concern releases 1370 10879 and 3673. And those are those circles on the western end of the row corridor. There were some elevated nitrate detections on the other side of the quarter as well near the dry bulk loading facility. So groundwater monitoring wells were also completed in those identified areas. And the monitoring while sampling also showed exceedances for the tier one RBSL's on those same lease sites. So this is their area of concern outline where they were looking to identify receptors to water wells were identified in the receptor survey. One well was damaged and removed when the grain silos were installed over the area in 2010. So that well is no longer there. The other well was installed in 2010 and used for spray down purposes. This well was drilled to a depth of 224 feet below great surface and it is no longer in use. So that well has been considered a non receptor. The site in the city obtained their water supply from the upper source water users district. There are numerous small season wetlands in the area. However, none were impacted. Okay, I'm going to hurry through. So here is the Andy Rebecca forms exceedance of the tier one is shown in the red. And that was for construction worker pathway. And so the assessment went on to a tier two. So this is showing a form number one, which kind of gives you an outline of the sites, the site conditions, a sum up of the site. It's the it's the quick cheat sheet for the site. So they did use our Andy Rebecca calculator and that was determined. That's what determined the tier two SSTL's in this site. Those numbers were used in the tier two reporting form to assess the site using the tier two. Okay, so form 21 for tier two is fate and transport parameters and these values for the site were updated using site specific values for the Tali role. The comment column updates automatically indicates whether default value or site specific value was used. So this site also went so far as to use a fate and transport model to assess the groundwater contamination plume that's on site. They use the Domenical model, which is one of our approved models to determine that the groundwater was going to retain on site and would not impact off site properties. So the tier two assessment pretty much indicated that groundwater contamination remained a completed pathway under future land considerations. So the recommendation on the site is several institutional controls and one of them was prohibiting domestic water use on site as well as further restrictions on building and impact lease areas. Also the soil and groundwater removed from impacted lease areas have to be properly managed. So how do those institutional controls work. This is the environmental covenant. The proposed melody was the institutional controls and that will be placed under an environmental covenant that runs with the property and establishes activity and use limitations or AULs on that property. So this environmental covenant and agreement that's made between the NDQ and the responsible party to ensure that future property users and our owners are aware of the protections put in place regarding any remaining contamination on site. Okay. I really went through that case study really fast because I'm running out of time, but I want to cover this really quick. So we introduced Rebecca formally in March of 2023. We have received a number of user feedback on the documents forms and calculators for Andy Rebecca which we appreciate because we're trying to make our process better and quicker and easier to use. So based on the comments that we have received, we're going to be issuing additional user guidance on the application of Andy Rebecca. So our technical document remains the same. That's considered our main document, but we are working on new forms, updated forms and guidance to make the forms easier to use, easier to understand. And we are hoping to release those additional forms and documents in May of 2024 in May of this year. And we're going to have training to follow. We're hoping to have training to training sessions, probably web based that will be available for free after May of this year. And you can keep updated on where we're at with our new materials and training through our websites, through direct communications, emails, and also you can track our social media.