Facilitating brownfields transactions using Triad and environmental insurance

A significant hindrance to reuse of brownfields properties is the risk associated with redevelopment,specifically the uncertainty associated with environmental cleanup. This article explores an approach tomanaging environmental risk through a combination of risk quantification, environmental insurance, and theTriad Approach to site sampling and data interpretation. The expected costs of environmental liabilities areestimated using the Marsh Peer ReviewSM risk quantification process that employs statistical techniques andhighly experienced technical staff. The outputs of the process indicate premiums and attachment points forinsurance products, but they also point to “critical uncertainties” that drive the insurancepremiums. Insurance premiums are often linked to site delineation deficiencies, such as the magnitude ofimpacted soil or the size of a groundwater plume. The Triad Approach is an integrated site characterizationprocess developed by the Environmental Protection Agency that combines systematic planning, dynamic or adaptivefield decision making and field analytical methods (FAMs). The real‐time data produced by FAMsallow for in‐field resolution of uncertainty about sample location, which in turn provides morerepresentative delineation of contaminant distribution. The trade‐off of using slightly less accuratebut substantially lower cost FAMs is an increase in sampling frequency or density, thereby reducing the risk ofincomplete detection or delineation while yielding a “data set” that is more powerful than fewerindividual data points analyzed through traditional methods. Employing the Triad Approach to analyze the“critical uncertainties” identified in the Peer Review Process can impact insurance premiums andallow for better terms of coverage. The combination of using the Triad Approach and environmental insuranceproducts can lead to more predictable and profitable Brownfield transactions. © 2003 Wiley Peridicals,Inc.     

Improved direct push technologies: Quicker and cheaper on-site methods for sampling and monitoring

Cost-effective remedial action is dependent on clear identification of site conditions and accurate delineation of contamination. Many site cleanups have been hampered by complex subsurface conditions. Standard drilling and monitoring well installations have proven to be costly and time-consuming. Improved direct push technologies, however, are being developed to perform quicker and less expensive on-site sampling and testing. This article describes the benefits of improved direct push technologies.     

Results of a field study—Sampling with ISOCS and SAM 935 at the Savannah River Site

This article focuses on the results of a delineation of radioactive contaminants using expedited field characterization equipment at the Department of Energy's Savannah River Site in South Carolina. The objective of the study was to delineate a potential contamination area in the TNX Inner Swamp using cost‐effective field sampling equipment that would give results in a timely manner. The expedited field characterization equipment used was the In Situ Object Counting System (ISOCS) and the Model 935 Surveillance and Measurement System (SAM 935). The study involved an area of approximately 200 acres with 89 surveyed locations. Originally, the contaminant of concern was thorium‐232 because of the health risk to future on‐site workers. As the fieldwork progressed, there were no exceedances in thorium‐232 activities; however, there was one slight exceedance of uranium‐238. The delineation was established from using the ISOCS and SAM 935 sampling equipment in addition to soil sampling from the 0‐ to 1‐foot interval. There was a strong correlation in the analytical data from both the ISOCS and SAM 935 measurements. Thus, this type of sampling characterization is beneficial for determining the extent of contamination at hazardous waste sites. © 2006 Wiley Periodicals, Inc.     

A method to compare groundwater cleanup technologies

DuPont has developed a method to compare, on a consistent economic basis, in situ remediation technologies. The methodology employs a template site with a perchloroethylene plume 1000 ft long by 400 ft wide, and incorporates various aquifer thicknesses and depths. Variables considered in the methodology include duration of the remediation; estimated engineering and flow/transport modeling costs; equipment costs; and operation, maintenance, and monitoring costs. In this article, substrate-enhanced anaerobic bioremediation, intrinsic bioremediation, in situ permeable reactive barriers, and pump-and-treat systems are evalutated. Cost metrics include present cost, cost per pound of contaminant removed, and cost per 1000 gals treated, using a discounted cash-flow analysis. Costs of the remedial alternatives increase starting from intrinsic bioremediation, to substrate-enhanced anaerobic bioremediation, to a biological substrate-enhanced anaerobic barrier, to in situ permeable reactive barriers, to pump-and-treat systems with air stripping and carbon adsorption.     

Evaluating the cost-effectiveness of new environmental technologies

The purpose of this article is to present a framework for evaluating the cost-effectiveness of innovative technologies for environmental characterization, remediation, monitoring, and waste management. The authors describe the steps involved in actually using the methodology to perform a cost-effectiveness analysis. They provide basic techniques for designing a fair comparison, developing scenarios, choosing a baseline technology, assessing relative performance, evaluating life-cycle costs, and calculating cost savings. Examples are used to illustrate these concepts and a case study is presented involving a new remediation technology called in-situ air stripping.     

Characterizing a Brownfields recreational reuse scenario using the Triad Approach–Assunpink Creek Greenways project

Since the early 1990s the U.S. government has been developing and implementing public policies that advance the redevelopment of brownfields, and the recent passage of the Small Business Liability Relief and Brownfields Revitalization Act (SBLRBRA) will significantly advance efforts to integrate environmental contamination mitigation and redevelopment. Experience has demonstrated that successful redevelopment requires the collection, analysis, and interpretation of environmental data in a timely and cost‐effective manner in order to allow developers and lenders to efficiently use cleanup resources, develop response strategies that integrate cleanup with redevelopment, and support meaningful outreach to involved stakeholders. Recent advances in the science and technology of site characterization hold the promise of improved site characterization outcomes while saving time and money. One such advancement, the Triad Approach, combines systematic up‐front planning with the use of a dynamic field investigation process and the generation of real time data to allow in‐field decision making on sample location selection. This article describes an application of the Triad Approach to redevelopment of an urban greenway in Trenton, New Jersey. The Triad Approach, initiated through a partnership between the City of Trenton, New Jersey Department of Environmental Protection, New Jersey Institute of Technology, and the U.S. Environmental Protection Agency, demonstrated that this approach could accelerate the characterization of the 60‐acre, 11‐parcel project area. Environmental issues that were solved using the Triad Approach included the delineation of the extent of historic fill, determination of no further action for several areas of concern, detailed investigation of specific impacted areas and the acquisition of sufficient data to allow the city to make important decisions regarding remediation costs and property acquisition. © 2003 Wiley Periodicals, Inc.     

A deterministic approach to evaluate and implement monitored natural attenuation for chlorinated solvents

A US EPA directive and related technical protocol outline the information needed to determine if monitored natural attenuation (MNA) for chlorinated solvents is a suitable remedy for a site. For some sites, conditions such as complex hydrology or perturbation of the contaminant plume caused by an existing remediation technology (e.g., pump‐and‐treat) make evaluation of MNA using only field data difficult. In these cases, a deterministic approach using reactive transport modeling can provide a technical basis to estimate how the plume will change and whether it can be expected to stabilize in the future and meet remediation goals. This type of approach was applied at the Petro‐Processors Inc. Brooklawn site near Baton Rouge, Louisiana, to evaluate and implement MNA. This site consists of a multicomponent nonaqueous‐phase source area creating a dissolved groundwater contamination plume in alluvial material near the Mississippi River. The hydraulic gradient of the groundwater varies seasonally with changes in the river stage. Due to the transient nature of the hydraulic gradient and the impact of a hydraulic containment system operated at the site for six years, direct field measurements could not be used to estimate natural attenuation processes. Reactive transport of contaminants were modeled using the RT3D code to estimate whether MNA has the potential to meet the site‐specific remediation goals and the requirements of the US EPA Office of Solid Waste and Emergency Response Directive 9200.4‐17P. Modeling results were incorporated into the long‐term monitoring plan as a basis for evaluating the effectiveness of the MNA remedy. As part of the long‐term monitoring plan, monitoring data will be compared to predictive simulation results to evaluate whether the plume is changing over time as predicted and can be expected to stabilize and meet remediation goals. This deterministic approach was used to support acceptance of MNA as a remedy. © 2007 Wiley Periodicals, Inc.     

Assessment of in situ thermal treatment for chlorinated organic source zones

The East Gate Disposal Yard (EGDY) at Fort Lewis is the source of a large trichloroethene (TCE) plume at this military installation. Source reduction using thermal treatment was applied using electrical resistance heating. A total of about 5,800 kg of TCE‐equivalent volatile organic compounds (VOCs; TCE and dichloroethene) was extracted during thermal treatment of the three zones selected for source reduction. Pretreatment groundwater TCE concentrations were measured up to 100 ppm. Posttreatment groundwater TCE concentrations within the treatment zones averaged less than 100 ppb. Posttreatment soil TCE concentrations decreased by over 96 percent compared to pretreatment soil concentrations. The overall contaminant flux from EGDY was reduced by an estimated 60 to 90 percent by the source reduction effort. The traditional and new techniques for site characterization and remediation performance monitoring applied at EGDY provide insight for installing, operating, monitoring, and assessing thermal treatment. © 2009 Wiley Periodicals, Inc.     

Cost estimating of the closure/post-closure phase

The U.S. Department of Energy (DOE) is beginning major environmental restoration projects of both active and inactive sites throughout the United States. The problems at the sites include contaminated soils, groundwater and surface waters, structures, and old waste disposal areas. IT Corporation, under the direction of the Office of Independent Cost Estimating (OICE) for DOE, developed a list of environmental problems at the sites and probable cleanup technologies and techniques that could be used. Estimated unit costs were then developed for these cleanup technologies, using available data and references. Some procedures developed were common to many or all cleanup projects. These included site characterization, remedial investigation (RI), feasibility studies (FS), and the closure/post-closure phase. The article will focus on cost estimating of the closure/post-closure phase of a cleanup project. The cost data provided are for budget level or check estimates. Site-specific conditions as well as items peculiar to the environmental industry, such as governmental regulations and community relations, can influence both the cost and duration of a cleanup project.     

Using pneumatic fracturing extraction to achieve regulatory compliance and enhance voc removal from low-permeability formations

The New Jersey Department of Environmental Protection and Energy (NJDEPE) has been developing cleanup regulations that focus on remediation, rather than extended delineation, and on integrating regulatory requirements with technological developments. To this end, the NJDEPE, under the regulatory aegis of the Environmental Cleanup and Responsibility Act (ECRA), is monitoring an innovative treatment technology pilot test at a TCE-contaminated ECRA site in Hillsborough, New Jersey. The purpose of the study is to determine the applicability of pneumatic fracturing extraction (PFE) as a source-removal technique for extracting volatile organic compounds (VOCs) trapped informations with low permeability. The technology being pilot tested is pneumatic fracturing extraction, a process for enhancing permeability to promote in-situ removal and treatment of VOCs. The patented process uses high-pressure air injected into an isolated subsurface zone at controlled rates and pressures. At a critical point, the geologic material ruptures, and fractures are created that radiate outward from the fracture location. At the pilot test site, formation air flow was increased from 400 percent to 700 percent. PFE is a key component of the overall remediation strategy at the Hillsborough site. Consistent with proposed NJDEPE regulations, a ground-water pump-and-treat system will be installed for plume migration control. Once the pump-and-treat system has been established and shown to be effective, a more aggressive source removal program will be implemented using PFE. This program will include construction of a vadose zone PFE system and evaluation of the use of pneumatic fracturing to remove saturated zone residual dense nonaqueous phase liquids (DNAPL). Preliminary calculations suggest that if source zone concentrations can be reduced to 10 ppm of TCE, then TCE groundwater concentrations may be reduced to background levels at the property boundary compliance points.     

Using an integrated approach for quantifying VOC source areas for site remediation

Locating and quantifying free-phase volatile organic compounds (VOCs) in the subsurface represent one of the more difficult challenges facing hazardous waste site remediation programs. Successful remediation programs require reliable data on the size and extent of potential VOC contamination sources. Improving subsurface quantification of VOCs requires a large number of reliable low-cost samples. Satisfying this objective relies on improved sampling techniques, field analysis of samples, and a modified quality assurance program. This paper describes an integrated approach using conventional split-spoon samplers, microcore sampling, hexane extractions, and a field gas chromatograph with an autosampler as part of a technical demonstration for innovative remediation technologies. Using this approach, it was possible to delineate a subsurface source of free-phase VOCs at a cost of $15 per sample. The distribution of dense nonaqueous phase liquid determined by this sampling approach agreed with the conceptual model for the site.     

Remediation of chlorinated ethenes,ethanes, and methanes in groundwater using carbon‐ and iron‐based electron donor

Field‐scale pilot tests were performed to evaluate enhanced reductive dechlorination (ERD) of dissolved chlorinated solvents at a former manufacturing facility located in western North Carolina (the site). Results of the site assessment indicated the presence of two separate chlorinated solvent–contaminated groundwater plumes, located in the northern and southern portions of the site. The key chlorinated solvents found at the site include 1,1,2,2‐tetrachloroethane, trichloroethene, and chloroform. A special form of EHC^® manufactured by Adventus Americas was used as an electron donor at this site. In this case, EHC is a pH‐buffering electron donor containing controlled release carbon and ZV Iron MicroSphere 200, a micronscale zero‐valent iron (ZVI) manufactured by BASF. Approximately 3,000 pounds of EHC were injected in two Geoprobe^® boreholes in the saprolite zone (southern plume), and 3,500 pounds of EHC were injected at two locations in the partially weathered rock (PWR) zone (northern plume) using hydraulic fracturing techniques. Strong reducing conditions were established immediately after the EHC injection in nearby monitoring wells likely due to the reducing effects of ZV Microsphere 200. After approximately 26 months, the key chlorinated VOCs were reduced over 98 percent in one PWR well. Similarly, the key chlorinated solvent concentrations in the saprolite monitoring wells decreased 86 to 99 percent after initial increases in concentrations of the parent chlorinated solvents. The total organic carbon and metabolic acid concentrations indicated that the electron donor lasted over 26 months after injection in the saprolite aquifer. © 2009 Wiley Periodicals, Inc.     

Expediting sustainable brownfields redevelopment by applying Triad using the membrane interface probe

Redevelopment and reuse plans are often based upon an expedited delineation and remediation life cycle, since delayed reuse usually has economic consequences. It has also become increasingly important to utilize sustainable practices to achieve investigation and remediation goals. In this article, the Triad approach is used to expedite the delineation of a source area within a municipal landfill to complete the remedial effort prior to construction of an urban civic center. The Triad approach uses the three elements of systematic project planning, dynamic work strategy, and real‐time measurement to expedite site characterization (Interstate Technology and Regulatory Council, 2003). In this article, the Triad sampling strategy consisted of two phases. The first phase included in situ screening of soil and groundwater using the membrane interface probe (MIP), and the second phase included confirmatory sampling via vertical profiles in the soil and groundwater. This study found that, using the MIP in a dynamic sampling strategy, a critical element of the Triad approach, combined with the proper placement of confirmatory samples, significantly reduced overall project cost and will expedite the site redevelopment. The use of the Triad approach also contributed to the integration of green and sustainable practices into the project. © 2010 Wiley Periodicals, Inc.     

Smart Characterization—An Integrated Approach for Evaluating a Complex 1,4‐Dioxane Site

Smart characterization approaches apply the latest high‐resolution site characterization methods to find the contaminant mass flux, by integrating relative permeability mapping, classical hydrostratigraphy interpretation, and high‐density groundwater and saturated soil sampling. The key factor that makes Smart characterization different is the application of quantitative saturated soil sampling in less permeable slow advection and storage zones to diagnose plume maturity and understand its implications for remedy selection and performance. Because direct sensing tools like the membrane interface probe are capable of providing screening‐level assessments for hydrocarbons and chlorinated solvents in storage zones, but not 1,4‐dioxane, the recommended Smart approach involves application of specialized high‐capacity mobile laboratories or rapid turn‐around using fixed commercial labs. In addition to the benefit of rapidly characterizing sites, Smart characterization facilitates a flux‐based conceptual site model, which allows stakeholders to focus remedies on the mobile portion of the contaminant mass or, in effect, the mass that matters. Through systematic planning and implementation, predesign characterization can be completed to optimize source and plume remedy strategies, balancing investment in Smart characterization with reductions in total life‐cycle costs to ensure that an appropriate return on investigation is obtained.  © 2016 Wiley Periodicals, Inc.     

Screening method for locating groundwater monitoring wells

The traditional approach to characterizing the extent of groundwater contamination is often phased over a period of several years. A screening method has been developed that allows the investigation process to be reduced to a single phase. Existing data are used to develop a preliminary estimate of the extent of contamination, which is refined by the screening method using groundwater data collected and analyzed in the field. The screening method is applicable at sites with volatile organic compound contamination. Groundwater samples are collected using direct push or drill rig assisted methods, and the groundwater headspace gas is analyzed for the contaminant of interest. The refined estimate is used to locate all of the groundwater monitoring wells necessary to finalize the estimate of the extent of contamination. Therefore, only one investigation phase is required, and time and cost savings are realized with respect to the traditional multiphase approach. The screening method was successfully applied at a CERCLA site in Nebraska with two distinct plumes of TCE-contaminated groundwater. The Nebraska remedial investigation was completed approximately 18 months earlier than the estimated completion of a comparable phased investigation, with a corresponding cost reduction estimated at approximately 10 percent. If data from the screening method were used instead of data from monitoring wells, the estimated cost savings would be over 50 percent. Additional applications and evaluations may lead to industry and regulatory acceptance of the method as a primary characterization tool.     

Biogeochemical gradients as a framework for understanding waste‐site evolution

The migration of biogeochemical gradients is a useful framework for understanding the evolution of biogeochemical conditions in groundwater at waste sites contaminated with metals and radionuclides. This understanding is critical to selecting sustainable remedies and evaluating sites for monitored natural attenuation, because most attenuation mechanisms are sensitive to geochemical conditions, such as pH and redox potential. Knowledge of how gradients in these parameters evolve provides insights into the behavior of contaminants with time and guides characterization, remedy selection, and monitoring efforts. An example is a seepage basin site at the Savannah River Site in South Carolina where low‐level acidic waste has seeped into groundwater. The remediation of this site relies, in part, on restoring the natural pH of the aquifer by injecting alkaline solutions. The remediation will continue until the pH upflow of the treatment zone increases to an acceptable value. The time required to achieve this objective depends on the time it takes the trailing pH gradient, the gradient separating the plume from influxing natural groundwater, to reach the treatment zone. Predictions of this length of time will strongly influence long‐term remedial decisions. © 2008 Wiley Periodicals, Inc.     

Closing the mass balance at chlorinated solvent sites: Sources and attenuation processes

Using detailed mass balance and simple analytical models, a spreadsheet‐based application (BioBalance) was developed to equip decision makers with a predictive tool that can provide a semiquantitative projection of source‐zone concentrations and provide insight into the long‐term behavior of the associated chlorinated solvent plume. The various models were linked in a toolkit in order to predict the composite impacts of alternative source‐zone remediation technologies and downgradient attenuation processes. Key outputs of BioBalance include estimates of maximum plume size, the time frame for plume stabilization, and an assessment of the sustainability of anaerobic natural attenuation processes. The toolkit also provides spatial and temporal projections of integrated contaminant flux and plume centerline concentrations. Results from model runs of the toolkit indicate that, for sites trying to meet traditional, “final” remedial objectives (e.g., two to three orders of magnitude reduction in concentration with restoration to potable limits), “dispersive” mechanisms (e.g., heterogeneous flow and matrix diffusion) can extend remedial time frames and limit the benefits of source remediation in reducing plume sizes. In these cases, the removal of source mass does not result in a corresponding reduction in the time frame for source remediation or plume stabilization. However, this should not discourage practitioners from implementing source‐depletion technologies, since results from the toolkit demonstrate a variety of measurable benefits of source remediation. Model runs suggest that alternative, “intermediate” performance metrics can improve and clarify source remediation objectives and better monitor and evaluate effectiveness. Suggested intermediate performance metrics include reduction in overall concentrations or mass within the plume, reduction of flux moving within a plume, and reduction in the potential for risk to a receptor or migration of a target concentration of contaminant beyond a site boundary. This article describes the development of two key modules of the toolkit as well as illustrates the value of using intermediate performance metrics to evaluate the performance of a source‐remediation technology. © 2010 Wiley Periodicals, Inc.     

In-situ application of colloidal activated carbon for PFAS-contaminated soil and groundwater: A Swedish case study

Soil and groundwater contamination by per- and polyfluoroalkyl substances (PFAS) has been a significant concern to human health and environmental quality. Remediation of contaminated sites is crucial to prevent plume expansion but can prove challenging due to the persistent nature of PFAS combined with their high aqueous mobility. In this case study, we investigated the potential of colloidal activated carbon (CAC) for soil stabilization at the pilot scale, aiming to entrap PFAS and prevent their leaching from soil into groundwater. Monitoring of the site revealed the presence of two potential sources of PFAS contamination at concentrations up to 23 μg L⁻¹ for ∑₁₁PFAS in groundwater. After CAC application, initial results indicated a 76% reduction of ∑₁₁PFAS and high removal rates for long-chain PFAS, such as perfluorooctane sulfonic acid and perfluorooctanoic acid. A spike in concentrations was noticed 6 months after injection of CAC, showing a rebound of the plume and a reduction of treatment effectiveness. Based on long-term monitoring data, the treatment effectiveness for ∑₁₁PFAS dropped to 52%. The rebound of concentrations was attributed to the plume bypass of the barrier due to the presence of high conductivity zones, which likely occurred because of seasonal changes in groundwater flow directions or the CAC application at the site. This demonstrates the need for a detailed and accurate hydrogeological understanding of contaminated sites before designing and applying stabilization techniques, especially at sites with high geologic and hydrologic complexity. The results herein can serve as a guideline for treating similar sites and help avoid potential pitfalls of remedial efforts.     

Directionally drilled horizontal wells offer cost savings and technical advantages over alternative soil and groundwater remediation systems

Directionally drilled horizontal wells offer the opportunity for significant cost savings and technical advantages over alternative trenched well and vertical well soil and groundwater remediation systems in many cases. The magnitude of the cost savings is a function of the remediation technology deployed and the values placed on the reduction of site impacts, dramatic reduction in the time required to achieve site remediation goals and requirements, the ability of horizontal well remediation to easily treat normally recalcitrant contaminants such as MTBE, and the ability to drill under paved areas, operating plants, residential areas, landfills, lagoons, waterways, ponds, basins, and other areas that are normally difficult or impossible to access with conventional drilling or trenching methods. In addition to improvements in site access capabilities, horizontal wells have been found capable of addressing contaminants that vertical wells do not readily treat, even with the same remediation technology deployed, especially if air‐based remediation technologies are deployed. With biosparging, for example, greater treatment capabilities of horizontal wells over vertical wells are attributed to greater oxygen flux over a broader area, a larger treatment zone, and extremely prolonged residence of groundwater contaminants in the aerobic treatment area, typically months or years. This article describes the use of directionally drilled horizontal wells for application of a variety of treatment technologies and includes costs of various options with a detailed comparison of biosparging options. © 2002 Wiley Periodicals, Inc.     

A data integration framework to support Triad projects

Cost‐effective and efficient site remediation and scientifically defensible decisions require site characterizations that are representative of site conditions. The Triad conceptual site model (CSM) is at the center of a continually improving site characterization process that begins during systematic planning and ends after the last data are developed. To gain the full benefit and greatest cost‐effectiveness, the process of CSM refinement should be performed in real time. Thus, the use of collaborative data is critical for evolving and maturing the CSM. In the field, through the use of all available data that are of known quality, a skilled and experienced field team can collect sufficient site information to mature the CSM in a timely manner. To facilitate the planning and execution of such a process, an easily understandable framework is needed to structure data quality that supports scientifically defensible decisions and efficient projects. This article explores such a framework. © 2004 Wiley Periodicals, Inc.