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.     

Using integrated food‐web and population‐based models for environmental monitoring,remediation decisions,and long‐term planning

While ecologists have used food‐web models to understand how ecosystems function, the potential role of integrated food‐web and population‐based models in environmental monitoring and decision making has been ignored. Sound ecological principles should be integrated with state‐of‐the‐art monitoring and management practices. This article presents the ways in which population‐based models can answer basic ecological questions necessary for decision making about remediation and restoration, and for monitoring to ensure long‐term stewardship. Discussed are the uses of food‐web and population‐based models for understanding the movement of chemicals through different trophic levels. Three examples, including global warming, tributyltin, and monomethylmercury scenarios, are presented to illustrate how such models are useful. The responses of the component parts varies, depending on parameters such as birth, death, and respiration, as well as feeding rates, predator‐prey rates, and uptake and elimination rates. There are several different models available for decision making, with different levels of complexity, based on the specific hypothesis or question being asked and the amount of current information available. Therefore, it is recommended to use deterministic‐based, population‐based food‐web models for ecological risk assessment. © 2001 John Wiley & Sons, Inc.     

Acetone and 2‐butanone creation associated with biological and chemical remediation of environmental contamination

Remediating environmental contamination by either biological or chemical methods typically results in the generation of temporary chemical intermediates as part of the process. These intermediate compounds may be related to either contaminant degradation pathways or reactions generated from the amendment itself. This article summarizes previously researched pathways and representative case studies discussing the authors' experience in generating relatively high concentrations of acetone and 2‐butanone (also referred to as methyl ethyl ketone [MEK]) during both biological and chemical treatments. Experience shows that even relatively high concentrations of acetone and MEK intermediates are quickly attenuated and prove not to be a hazard outside of the treatment area. © 2011 Wiley Periodicals, Inc.     

Stable Isotope Probing to Confirm Field‐Scale Co‐Metabolic Biodegradation of 1,4‐Dioxane

1,4‐Dioxane, a common co‐contaminant with chlorinated solvents, is present in groundwater at Site 24 at Vandenberg Air Force Base in California. Historical use of chlorinated solvents resulted in concentrations of 1,4‐dioxane in groundwater up to approximately 2,000 μg/L. Starting in 2013, an in situ propane biosparge system operation demonstrated reductions in 1,4‐dioxane concentrations in groundwater. The work detailed herein extends the efforts of the first field demonstration to a second phase and confirms the biodegradation mechanism via use of stable isotope probing (SIP). After two months of operation, 1,4‐dioxane concentrations decreased approximately 45 to 83 percent at monitoring locations in the test area. The results of the SIP confirmed ¹³C‐enriched 1,4‐dioxane was transformed into dissolved inorganic carbon (suggesting mineralization to carbon dioxide) and incorporated into microbial biomass (likely attributed to metabolic uptake of biotransformation intermediates or of carbon dioxide).  ©2016 Wiley Periodicals, Inc.     

Editor's perspective‐‐‐Shale gas development: Environmental issues and opportunities

Many professionals in the environmental industry have questioned whether the rapid expansion in shale gas development, particularly in the Marcellus Shale Play, is providing business opportunities. While gas production is a routine practice, the development of shale gas requires a process (fracturing, or, more commonly, “fracing'') that uses chemicals and is far more intrusive to the subsurface environment than traditional gas production. In this Editor's Perspective, we evaluate the environmental issues surrounding shale gas development, with a specific focus on the Marcellus Shale Play because it is currently the most active play in the United States, from both the drilling and political perspectives. In addition, we examine where the business opportunities are likely to be for environmental professionals relative to shale gas development. © 2011 Wiley Periodicals, Inc.     

In‐Canal Stabilization/Solidification of NAPL‐Impacted Sediments

In situ solidification (ISS) has been used with increasing frequency as a remedial technology for source area treatment at upland sites impacted with a variety of organic contaminants, including coal tar, creosote, and other nonaqueous phase liquids (NAPLs). With several large, complex, urban water ways and rivers impacted with NAPLs, ISS is more recently being considered as a technology of choice to help reduce remedial costs, minimize short‐ and long‐term impacts of mobile NAPL, and lower the carbon footprint. This article presents the results of a successful pilot study of ISS at the Gowanus Canal Superfund site in Brooklyn, New York. This represents the first major sediment ISS field demonstration project in a saline environment and the first project to evaluate large‐scale implementation of ISS from a barge and through overlaying sediment. ©2016 Wiley Periodicals, Inc.     

Full‐scale bioremediation of a dilute 50‐acre plume

Enhanced anaerobic dechlorination is being conducted to remediate a 50‐acre groundwater area impacted with chlorinated volatile organic compounds (CVOCs). The plume, which is over 3,000 feet (ft) long, initially contained tetrachloroethene and breakdown products at concentrations of 2 to 3 milligrams per liter. The site's high groundwater flow velocity (greater than 1,000 ft per year) was incorporated into the design to help with amendment distribution. Bioaugmentation was conducted using a mixed culture containing Dehalococcoides ethenogenes. There is evidence that it has migrated to distances exceeding 600 ft. The major benefit of the high groundwater flow velocity is greater areal coverage by the remediation system, but the downside is the difficulty in delivering sufficient donor to create the required anaerobic conditions. Overall performance has been excellent with total CVOC reductions and conversion to ethene of 98 percent within a 25‐acre area downgradient of the treatment transect that has operated the longest. © 2011 Wiley Periodicals, Inc.     

Complete Degradation of Hexahydro‐1,3,5‐Trinitro‐1,3,5‐Triazine (RDX) by a Co‐Culture of Gordonia sp. KTR9 and Methylobacterium sp. JS178

The presence of hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX) in soil and groundwater is a major contamination issue at many military facilities around the world. Gordonia sp. KTR9 metabolizes RDX as a nitrogen source for growth producing 4‐nitro‐2,4‐diazabutanal (NDAB) as a dead‐end product. Methylobacterium sp. strain JS178 degrades NDAB as a sole source of nitrogen for growth. A mixed culture of strains KTR9 and JS178 was able to completely degrade RDX. There was no difference in rate of RDX degradation by KTR9 alone or in co‐culture with JS178. The first‐order degradation coefficients of RDX and NDAB in the co‐culture were 0.08 hr^?1 and 0.002 hr^?1, respectively. In the co‐culture that initially contained RDX plus NDAB, strain JS178 degraded the NDAB that was produced by KTR9 as shown by a decrease in the molar yield of NDAB (from RDX) from 1.0 to –0.11. Co‐cultures of strains KTR9 and JS178 could be used to promote complete degradation of RDX in soils or groundwater. ©2016 Wiley Periodicals, Inc.     

Residential vapor‐intrusion evaluation: Long‐duration passive sampling vs. short‐duration active sampling

Sampling indoor air for potential vapor‐intrusion impacts using current standard 24‐hour sample collection methods may not adequately account for temporal variability and detect contamination best represented by long‐term sampling periods. Henry Schuver of the U.S. Environmental Protection Agency Office of Solid Waste stated at the September 2007 Air & Waste Management Association vapor‐intrusion conference that the US EPA may consider recommending longer‐term vapor sampling to achieve more accurate time‐weighted‐average detections. In November 2007, indoor air at four residences was sampled to measure trichloroethene (TCE) concentrations over short‐ and long‐duration intervals. A carefully designed investigation was conducted consisting of triplicate samplers for three different investigatory methods: dedicated 6‐liter Summa canisters (US EPA Method TO‐15), pump/sorbent tubes (US EPA Method TO‐17), and passive diffusion samplers (MDHS 80). The first two methods collected samples simultaneously for a 24‐hour period, and the third method collected samples for two weeks. Data collected using Methods TO‐15 (canisters) and TO‐17 (tubes) provided reliable short‐duration TCE concentrations that agree with prior 24‐hour sampling events in each of the residences; however, the passive diffusion samplers may provide a more representative time‐weighted measurement. The ratio of measured TCE concentrations between the canisters and tubes are consistent with previous results and as much as 28.0 μg/m³ were measured. A comparison of the sampling procedures, and findings of the three methods used in this study will be presented. © 2008 Wiley Periodicals, Inc.     

Re‐evaluation of treatment approach for a site contaminated with Freon‐113 and 1,1,1‐trichloroethane

This study demonstrates a remedial approach for completing the remediation of an aquifer contaminated with 1,1,2‐trichlorotrifluoroethane (Freon‐113) and 1,1,1‐trichloroethane (TCA). In 1987, approximately 13,000 pounds of Freon‐113 were spilled from a tank at an industrial facility located in the state of New York. The groundwater remediation program consisted of an extraction system coupled with airstripping followed by natural attenuation of residual contaminants. In the first phase, five recovery wells and an airstripping tower were operational from April 1993 to August 1999. During this time period over 10,000 pounds of CFC‐13 and 200 pounds of TCA were removed from the groundwater and the contaminant concentrations decreased by several orders of magnitude. However, the efficiency of the remediation system to recover residual Freon and/or TCA reduced significantly. This was evidenced by: (1) low levels (< 10 ppb) of Freon and TCA captured in the extraction wells and (2) a slight increase of Freon and/or TCA in off‐site monitoring wells. A detailed study was conducted to evaluate the alternative for the second‐phase remediation. Results of a two‐year groundwater monitoring program indicated the contaminant plume to be stable with no significant increase or decrease in contaminant concentrations. Monitored geochemical parameters suggest that biodegradation does not influence the fate and transport of these contaminants, but other mechanisms of natural attenuation (primarily sorption and dilution) appear to control the fate and transport of these contaminants. The contaminants appear to be bound to the soil matrix (silty and clay units) with limited desorption as indicated by the solid phase analyses of contaminant concentrations. Results of fate and transport modeling indicated that contaminant concentrations would not exceed the action levels in the wells that showed a slight increase in contaminant concentrations and in the downgradient wells (sentinel) during the modeled timeframe of 30 years. This feasibility study for natural attenuation led to the termination of the extraction system and a transaction of the property, resulting in a significant financial benefit for the original site owner. © 2003 Wiley Periodicals, Inc.     

A chemox treatment for urea‐ and ammonium‐contaminated groundwater

In a pilot project performed at a fertilizer manufacturing facility, a one‐step chemical oxidation technique successfully treated urea‐ and ammonium‐contaminated groundwater. The oxidation reaction occurred in an 1,100‐gallon batch reactor. The contaminated inflow was buffered by the metered addition of sodium bicarbonate solution and subsequently treated with sodium hypochlorite in an 8:1 weight ratio of Cl₂:N. In an instantaneous reaction, the urea and ammo‐nium‐N were completely oxidized to nitrogen gas that was vented to the atmosphere during mixing. The pH of the reactor discharge was ?6.5. Sodium sulfite was used to reduce residual hypochlorite in the reactor effluent to chloride to provide process water with characteristics suitable for discharge. Oxidation rates were similar with different strengths of hypochlorite; however, a 5 to 6 percent sodium hypochlorite (as Cl₂) solution was the most stable. © 2005 Wiley Periodicals, Inc.     

Evaluation of natural attenuation at a 1,4‐dioxane‐contaminated site

1,4‐Dioxane entered the environment as a result of historic leaks and spills in the production area at an industrial facility in the southeastern coastal plain. The areal extent of the 1,4‐dioxane plume is several hundred acres and is largely contained on the site. Land use adjacent to the plant property is primarily undeveloped (wetlands or woods) or industrial, with a small area of mixed land use (commercial/residential) to the southwest and north. The surficial aquifer is a relatively simple hydrogeologic system with well‐defined boundaries and is comprised of a 50‐ to 70‐foot‐thick deposit of alluvial/fluvial sand and gravel that overlies an aquitard in excess of 100 feet thick. A groundwater flow model, developed and calibrated using field‐measured data, was used for the fate‐and‐transport modeling of 1,4‐dioxane. The flow‐and‐transport model, combined with the evaluation of other site geochemical data, was used to support the selection of monitored natural attenuation (MNA) as the proposed groundwater remedy for the site. Since the active sources of contamination have been removed and the modeling/field data demonstrated that the plume was stable and not expanding, the proposed MNA approach was accepted and approved by the regulatory agency for implementation in 2004. Subsequent accumulated data confirm that concentrations in the 1,4‐dioxane plume are declining as predicted by the fate‐and‐transport modeling. © 2008 Wiley Periodicals, Inc.     

Matrix Diffusion Modeling Applied to Long‐Term Pump‐and‐Treat Data: 1. Method Development

Despite the installation in the 1980s and 1990s of hydraulic containment systems around known source zones (four slurry walls and ten pump‐and‐treat systems), trichloroethene (TCE) plumes persist in the three uppermost groundwater‐bearing units at the Middlefield‐Ellis‐Whisman (MEW) Superfund Study Area in Mountain View, California. In analyzing TCE data from 15 recovery wells, the observed TCE mass discharge decreased less than an order of magnitude over a 10‐year period despite the removal of an average of 11 pore volumes of affected groundwater. Two groundwater models were applied to long‐term groundwater pump‐and‐treat data from 15 recovery wells to determine if matrix diffusion could explain the long‐term persistence of a TCE plume. The first model assumed that TCE concentrations in the plume are controlled only by advection, dispersion, and retardation (ADR model). The second model used a one‐dimensional diffusion equation in contact with two low‐permeability zones (i.e., upper and lower aquitard) to estimate the potential effects of matrix diffusion of TCE into and out of low‐permeability media in the plume. In all 15 wells, the matrix diffusion model fit the data much better than the ADR model (normalized root mean square error of 0.17 vs. 0.29; r² of 0.99 vs. 0.19), indicating that matrix diffusion is a likely contributing factor to the persistence of the TCE plume in the non‐source‐capture zones of the MEW Study Area's groundwater‐extraction wells. © 2013 Wiley Periodicals, Inc.     

Effectiveness of Capture Zones Generated by Intermittent Pumping of a PV‐Powered Pump‐and‐Treat System Without Energy Storage

A common technology to remediate and/or contain contaminated groundwater is pump‐and‐treat remediation (P&T). Traditionally, P&T systems have been designed to operate continuously to achieve steady‐state capture zones, for which large amounts of energy are required. Green and sustainable remediation (GSR) is emerging as a viable method to minimize the adverse effects of remediation on the environment. One of the challenges associated with photovoltaic‐ (PV‐) powered P&T systems is the assessment of their performance given the intermittent nature of the power availability. This article characterizes the hydraulic containment effectiveness of a PV‐powered P&T system without energy storage using data collected at two different remediation sites, a Dry‐Cleaning Environmental Response Trust Fund site in Rolla, Missouri, and the Former Nebraska Ordnance Plant near Mead, Nebraska. Additionally, a method to estimate the effectiveness of the hydraulic containment as a function of the total volume of groundwater expected to be extracted is being proposed. Two transient and a continuously pumped capture zones were modeled using Visual MODFLOW^® 2012.1 along with MODPATH and compared. The study shows that smaller capture zones will be generated from intermittent pumping when compared to continuous pumping. © 2013 Wiley Periodicals, Inc.     

TCE plume remediation via ISCR‐enhanced bioremediation utilizing EHC® and KB‐1®

Groundwater below an operating manufacturing facility in Portland, Oregon, was impacted by chlorinated volatile organic compounds (CVOCs), with concentrations indicative of a dense, nonaqueous‐phase liquid (DNAPL) release. The downgradient plume stretched under the adjacent Willamette River, intersecting zones of legacy impacts from a former manufactured gas plant (MGP). An evaluation of source‐area and downgradient plume treatment remedies identified in situ bioremediation as most likely to be effective for the CVOC plume, while leaving the legacy impacts for other responsible parties. With multiple commercially available products to choose from, the team developed and implemented a bench test to identify the most appropriate technology, which was further evaluated in a field pilot study. The results of the testing demonstrated conclusively that bioremediation enhanced by in situ chemical reduction (ISCR) using EHC® and KB‐1® was most appropriate for this site, providing outstanding results. The following describes the implementation and results of the tests. © 2008 Wiley Periodicals, Inc.     

Evaluation of white‐rot fungi for the remediation of creosote‐contaminated soil

Application of fungal‐based bioaugmentation was evaluated for the remediation of creosote‐contaminated soil at a wood‐preserving site in West Virginia. Soil at the site contained creosote‐range polycyclic aromatic hydrocarbons (PAHs) at concentrations in some areas that exceed industrial risk‐based levels. Two white‐rot fungi (Pleurotus ostreatus and Irpex lacteus) were evaluated for remediation effectiveness in a two‐month bench‐scale treatability test. Both fungi produced similar results, with up to 67.3 percent degradation of total PAHs in 56 days. Pilot‐scale testing was performed at the site using Pleurotus ostreatus grown on two local substrate mixtures. During the 276‐day field trial, total PAHs were degraded by up to 93.2 percent, with all individual PAHs except one achieving industrial risk‐based concentrations. It was recommended that fungal‐based remediation be applied to all contaminated soil at the site. © 2002 Wiley Periodicals, Inc.     

Surfactant‐Oxidant Co‐Application for Soil and Groundwater Remediation

In situ chemical oxidation (ISCO) typically delivers oxidant solutions into the subsurface for contaminant destruction. Contaminants available to the oxidants, however, are limited by the mass transfer of hydrophobic contaminants into the aqueous phase. ISCO treatments therefore often leave sites with temporarily clean groundwater which is subject to contaminant rebound when sorbed and free phase contaminants leach back into the aqueous phase. Surfactant Enhanced In situ Chemical Oxidation (S‐ISCO^®) uses a combined oxidant‐surfactant solution to provide optimized contaminant delivery to the oxidants for destruction via desorption and emulsification of the contaminants by the surfactants. This article provides an overview of S‐ISCO technology, followed by an implementation case study at a coal tar contaminated site in Queens, New York. Included are data points from the site which demonstrate how S‐ISCO delivers desorbed contaminants without uncontrolled contaminant mobilization, as desorbed and emulsified contaminants are immediately available to the simultaneously injected oxidant for reaction. ©2016 Wiley Periodicals, Inc.     

Breakthrough in 2D‐CSIA Technology for 1,4‐Dioxane

A dual isotope technology based on compound‐specific stable isotope analysis of carbon and hydrogen (2D‐CSIA) was recently developed to help identify sources and monitor in situ degradation of the contaminant 1,4‐dioxane (1,4‐D) in groundwater. Site investigation and optimized remediation have been the focus of thousands of CSIA applications completed for volatile organic contaminants (VOCs) worldwide. CSIA for the water miscible 1,4‐D, however, has been technically challenging. The most commercially available sample preparation settings “Purge and Trap” for VOC could not efficiently extract 1,4‐D out of water for a reliable CSIA measurement, especially when the concentration is below 100 μg/L. Such a high reporting limit has prevented CSIA from being used for effective site investigation and remediation monitoring at most 1,4‐D contaminated sites, where 1,4‐D is often present at very low ppb levels. This article outlines the recent breakthrough in 2D‐CSIA technology for 1,4‐D in water, reported down to ～1 μg/L for carbon, and ～10 μg/L to 20 μg/L for hydrogen using solid‐phase extraction based on EPA Method 522, and its benefit is highlighted through a case study at a 1,4‐D contaminated site. ©2016 Wiley Periodicals, Inc.     

Treatment of Perchlorate‐Contaminated Groundwater Using Highly Selective,Regenerable Ion‐Exchange Technology: A Pilot‐Scale Demonstration

Treatment of perchlorate‐contaminated groundwater using highly selective, regenerable ion‐exchange technology has been recently demonstrated at Edwards Air Force Base, California. At an influent concentration of about 450 μg/l ClO₄^?, the bifunctional anion‐exchange resin bed treated approximately 40,000 empty bed volumes of groundwater before a significant breakthrough of ClO₄^? occurred. The presence of relatively high concentrations of chloride and sulfate in site groundwater did not appear to affect the ability of the bifunctional resin to remove ClO₄^?. The spent resin bed was successfully regenerated using the FeCl₃^?HCl regeneration technique recently developed at the Oak Ridge National Laboratory, and nearly 100 percent of sorbed ClO₄^? was displaced or recovered after elution with as little as about two bed volumes of the regenerant solution. In addition, a new methodology was developed to completely destroy ClO₄^? in the FeCl₃^?HCl solution so that the disposal of perchlorate‐containing hazardous wastes could be eliminated. It is therefore anticipated that these treatment and regeneration technologies may offer an efficient and cost‐effective means to remove ClO₄^? from contaminated groundwater with significantly reduced generation of waste requiring disposal. © 2002 Wiley Periodicals, Inc.