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.     

Triad case study: Marine Corps Base Camp Pendleton

The U.S. Navy Public Works Center (PWC) Environmental Department, San Diego, California, is home to the Navy West Coast Site Characterization and Analysis Penetrometer System (SCAPS). SCAPS has been extensively used at several Navy sites since 1995 to provide real‐time, high‐density data sets. The U.S. Environmental Protection Agency's Triad approach provided an ideal framework for optimizing the use of the Navy SCAPS during a volatile organic compound (VOC) source investigation at Installation Restoration Site 1114 at Marine Corps Base Camp Pendleton. All three elements of Triad—systematic planning, dynamic work strategy, and use of real‐time measurement tools—were implemented to manage decision uncertainty and expedite the site management process. The investigation was conducted using the Navy SCAPS, outfitted with a cone penetrometer, membrane interface probe, and a direct sampling ion trap mass spectrometry detector, which allowed for real‐ time collection of over 690 feet of continuous lithologic information and VOC concentration data. These data were used collaboratively with 24‐hour turnaround US EPA 8260B VOC groundwater results from temporary direct‐ push wells to support the conclusion of a limited source area. Implementation of the Triad approach for this investigation provided an expedited high‐density data set and a refined conceptual site model (CSM) in real time that resulted in cost savings estimated at $2.5M and reduction of the site characterization and cleanup schedule by approximately three years. This project demonstrates how the US EPA's Triad approach can be applied to streamline the site characterization and cleanup process while appropriately managing decision uncertainty in support of defensible site decisions. © 2004 Wiley Periodicals, Inc.     

Optimizing remediation strategies for a former dry‐cleaner site

Residual tetrachloroethene (PCE) contamination at the former Springvilla Dry Cleaners site in Springfield, Oregon, posed a potential risk through the vapor intrusion, direct contact, and off‐site beneficial groundwater uses. The Oregon Department of Environmental Quality utilized the State Dry Cleaner Program funds to help mitigate the risks posed by residual contamination. After delineation activities were complete, the source‐area soils were excavated and treated on‐site with ex situ vapor extraction to reduce disposal costs. Residual source‐area contamination was then chemically oxidized using sodium permanganate. Dissolved‐phase contamination was subsequently addressed with in situ enhanced reductive dechlorination (ERD). ERD achieved treatment goals across more than 4 million gallons of aquifer impacted with PCE concentrations up to 7,800 micrograms per liter prior to remedial activities. The ERD remedy introduced electron donors and nutrient amendments through groundwater recirculation and slug injection across two aquifers over the course of 24 months. Adaptive and mass‐targeted strategies reduced total remedy costs to approximately $18 per ton within the treatment areas. © 2010 Wiley Periodicals, Inc.     

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.     

Triad case study: Rattlesnake Creek

The U.S. Army Corps of Engineers (US ACE) is responsible for conducting the cleanup of radiological contaminated properties as part of the Formerly Utilized Sites Remedial Action Program. One property is the Rattlesnake Creek (RSC) portion of the Ashland sites. The RSC stream sediments are contaminated with thorium‐230, radium‐226, and uranium. The US ACE is closing RSC using protocols contained within the Multi‐Agency Radiation Survey and Site Investigation Manual (MARSSIM). At RSC, the US ACE developed site‐specific derived concentration guideline level (DCGL) cleanup requirements consistent with the MARSSIM guidance. Because of uncertainty about the distribution of contamination within the creek, the US ACE used the Triad approach to collect data and design remedial actions. Systematic planning helped target the areas of concern, develop a conceptual site model, and identify data gaps to be addressed before remediation plans were finalized. Preremediation sampling and analysis plans were designed to be explicitly consistent with final status survey requirements, allowing data sets to support both excavation planning needs and closure requirements in areas where contamination was not encountered above DCGL standards. Judicious use of real‐ time technologies such as X‐ray fluorescence and gamma walkover surveys minimized expensive off‐ site alpha spectrometry analyses, and at the same time provided the ability to respond to unexpected field conditions. © 2004 Wiley Periodicals, Inc.     

Per‐ and polyfluoroalkyl substances in environmental sampling products: Fact or fiction?

Can per‐ and polyfluoroalkyl substances (PFAS) be transferred from the common field and other commercial products during sampling? Special handling and care are always advised when collecting samples for PFAS analysis to avoid sample contamination. The potential presence of PFAS in common consumer products and in equipment typically used to collect environmental samples, coupled with the need for very low reporting limits heightens this concern. In this paper, the authors investigate what the potential for cross‐contamination is from a number of commonly used products, with the emphasis on evaluating what the possible worst‐case scenario for cross‐contamination could be. Polytetrafluoroethylene (PTFE), low‐density polyethylene (LDPE), and high‐density polyethylene (HDPE) tubing, pump bladders, and other materials are evaluated along with associated products such as aluminum foil and plastic storage bags. In the experimental design of this study, the products themselves are not analyzed directly for PFAS. Rather, a series of experiments are performed utilizing a leaching procedure to evaluate the potential for cross‐contamination and false‐positive environmental sampling results. This study was performed in a series of experimental batches over the course of a 1‐year period. Analytical results are presented along with experimental observations and recommendations.     

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.     

Cost-effective contaminant plume delineation using multilevel drive point samplers

Over the past several years, environmental professionals have sought new and innovative field techniques to allow on-site plume delineation and in-field location of monitoring wells. One technique adopted for site characterization is the multilevel drive point sampler (MLDPS). This technology allows sampling of soil gas and groundwater and measurement of aquifer permeability. MLDPSs offer a cost-effective solution to the high cost of plume delineation by providing in-field data for decisions on monitoring well location and depth. MLDPS technologies can increase the effectiveness of monitoring well installation programs, decrease the cost of site characterization, and accelerate the time between initial site assessment and implementation of a remediation program. MLDPS technologies offer distinct advantages over other field techniques, and a cost comparison is offered. A case study describing application of the MLDPS to the delineation of a TCE-contaminated plume is described.     

Adaptive sampling and analysis programs for contaminated soils

Adaptive sampling and analysis programs (ASAPs) provide a cost-effective alternative to traditional sampling program designs. ASAPs are based on field analytical methods for rapid sample turnaround and field-based decision support for guiding the progress of the sampling program. One common objective of ASAPs is to delineate contamination present in soils, either to support feasibility studies or remedial action designs. An ASAP based on portable gas chromatograph/ mass spectrograph (GC/MS) technologies developed at Tufts University combined with decision support tools created at Argonne National Laboratory was used to delineate explosives contamination in soils at Joliet Army Ammunition Plant, Joliet, Illinois. Tufts' GC/MS technologies provided contaminant-specific identification and quantification with rapid sample turnaround and high sample throughput. Argonne's decision support tools estimated contamination extent, determined the uncertainty associated with those estimates, and indicated where sampling should continue to minimize uncertainty. In the case of Joliet, per sample analytical costs were reduced by 75 percent as compared to the cost of off-site laboratory analyses for explosives. The use of an ASAP resulted in a much more accurate identification and delineation of contaminated areas than a traditional sampling program would have with the same number of samples collected on a regular grid. While targeting explosives contamination in soils at Joliet, the ASAP technologies used in this demonstration have much broader application.     

Evaluating PFAS cross contamination issues

Avoiding cross contamination from per‐ and polyfluoroalkyl substances (PFAS) that may occur during sampling of environmental media is the key to ensure reliable analytical results during a PFAS sampling program. Due to the ubiquitous nature of PFAS in commonly used sampling materials and personal protective equipment, mitigating the risk of cross contamination is a challenge that requires a conservative approach when planning and executing a PFAS sampling program. This article describes a conservative approach to PFAS sampling and includes a case study that evaluated three insect repellent products to determine their suitability for use during PFAS investigation. The three products were verified to be PFAS‐free for the 17 PFAS included in the analysis and, therefore, these products are suitable for use during PFAS sampling activities without concern for cross contamination.     

Scenario‐Based Evaluation of Commercially Available Cleaning Robots for Collection of Bacillus Spores from Environmental Surfaces

The cleaning robots, a vacuum‐based robot (R2) and a wetted‐wipe‐based robot (R4), were evaluated in this study to determine their effectiveness for sampling Bacillus atrophaeus spores. The tests were designed to evaluate the benefit of robot sampling on large areas with two different contamination scenarios: a high‐concentration, low spatial extent contamination (hot spot) and a low concentration, high spatial extent contamination (widely dispersed). The hot spot tests were conducted with the high spore contamination (approximately 10⁷ colony forming units [CFUs]) on a limited area (30.5 cm × 30.5 cm), 2 percent of the entire test. The widely dispersed tests were conducted with approximately 0.1 CFUs/cm² for floor laminate and approximately 10 CFUs/cm² for carpet surfaces. The widely dispersed tests distributed spores across the test surface and covered approximately 40 percent of the entire test area. The test results showed that both robots successfully sampled a large quantity of spores from carpet and floor laminate surfaces for both test scenarios. Robot performance is discussed in the context of currently used surface sampling methods. © 2014 Wiley Periodicals, Inc.*     

Successful unsaturated zone treatment of PCE with sodium permanganate

In situ chemical oxidation (ISCO) with permanganate has been widely used for soil and groundwater treatment in the saturated zone. Due to the challenges associated with achieving effective distribution and retention in the unsaturated zone, there is a great interest in developing alternative injection technologies that increase the success of vadose‐zone treatment. The subject site is an active dry cleaner located in Topeka, Kansas. A relatively small area of residual contamination adjacent to the active facility building has been identified as the source of a large sitewide groundwater contamination plume with off‐site receptors. The Kansas Department of Health and Environment (KDHE) currently manages site remedial efforts and chose to pilot‐test ISCO with permanganate for the reduction of perchloroethene (PCE) soil concentrations within the source area. KDHE subsequently contracted Burns & McDonnell to design and implement an ISCO pilot test. A treatability study was performed by Carus Corporation to determine permanganate‐soil‐oxidant‐demand (PSOD) and the required oxidant dosing for the site. The pilot‐test design included an ISCO injection approach that consisted of injecting aqueous sodium permanganate using direct‐push technology with a sealed borehole. During the pilot test, approximately 12,500 pounds of sodium permanganate were injected at a concentration of approximately 3 percent (by weight) using the methods described above. Confirmation soil sampling conducted after the injection event indicated PCE reductions ranging from approximately 79 to more than 99 percent. A follow‐up treatment, consisting of the injection of an additional 6,200 pounds of sodium permanganate, was implemented to address residual soil impacts remaining in the soil source zone. Confirmation soil sampling conducted after the treatment indicated a PCE reduction of greater than 90 percent at the most heavily impacted sample location and additional reductions in four of the six samples collected. © 2009 Wiley Periodicals, Inc.     

Triad case study: Former small arms training range

The U.S. Army Corps of Engineers (US ACE) used the Triad approach to expedite site characterization of contaminated soil at the Former Small Arms Evergreen Infiltration Training Range in Fort Lewis, Washington. The characterization was designed to determine if surface soils contain significant concentrations of metals, with the focus on collecting sufficient data for determining appropriate future actions (i.e., risk analysis or soil remediation). A dynamic sampling and analytical strategy based on rapid field‐based analytical methods was created in order to streamline site activities and save resources while increasing confidence in remediation decisions. Concurrent analysis of soil samples during the demonstration of method applicability (DMA) used both field portable X‐ray fluorescence (FPXRF) and laboratory methodologies to establish a correlation between FPXRF and laboratory data. Immediately following the DMA, contaminated soil from the impact berm was delineated by collecting both FPXRF data and fixed laboratory confirmation samples. The combined data set provided analytical results that allowed for revisions to the conceptual site model for the range and directed additional sample collection activities to more clearly determine the extent and distribution of soil contamination. © 2004 Wiley Periodicals, Inc.     

Site characterization to support permeable reactive barrier design

Careful design studies and selection of an effective technique for the installation of permeable reactive barriers (PRBs) are important contributors to the overall success of zero‐valent iron PRBs. This article provides a case study summarizing the successful design and construction of a PRB installed at the former Carswell Air Force Base located in Fort Worth, Texas. Expedited site characterization using a cone penetrometer rig equipped with a mass spectrometer was employed to provide real‐time characterization and lithologic data. These data proved to be invaluable for the design of the PRB and allowed for the development of an accurate preconstruction cost estimate. Field data gained from the expedited water quality and geologic characterization along with aquifer testing and a bench‐scale treatability study provided a comprehensive basis for the design. The biopolymer slurry construction technique provided additional unanticipated benefits to the designed zero‐ valent iron treatment by promoting the development of anaerobic conditions favorable for microbial degradation of trichloroethene. Postconstruction monitoring data are discussed to illustrate the successful performance of the PRB. © 2005 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.     

Combined thermal and zero‐valent iron In Situ soil mixing remediation technology

Thermal remediation of contaminated soils and groundwater by injection of hot air and steam using large‐diameter auger in situ soil mixing effectively remediates volatile and semivolatile organic compounds. This technology removes large amounts of contamination during the early treatment stages, but extended treatment times are needed to achieve high removal percentages. Combining thermal treatment with another technology that can be injected and mixed into the soil, and that continues to operate after removal of the drilling equipment, improves removal efficiency, and reduces cost. Using field‐determined pseudo first‐order removal rates, the cost of the combined remediation of chlorinated volatile organic compounds (CVOCs) by thermal treatment followed by reductive dechlorination by iron powder has been estimated as 57 percent of the cost of thermal treatment alone. This analysis was applied to a case‐study remediation of 48,455 cubic yards, which confirmed the cost estimate of the combined approach and showed over 99.8 percent removal of trichloroethene and other chlorinated VOCs. © 2010 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.     

Laboratory validation study of new vapor‐phase‐based approach for groundwater monitoring

Recent improvements in field‐portable analytical equipment allow accurate on‐site measurement of VOCs present in air at concentrations of less than 0.1 parts per million volume (ppmv). The objective of this project is to determine if the use of these instruments for vapor‐phase measurements of headspace in a monitoring well can serve as a reliable and accurate method for monitoring volatile organic compound (VOC) concentrations in groundwater under equilibrium conditions. As part of a comprehensive research project investigating the utility of this proposed monitoring method, the authors have completed a laboratory validation study to identify instruments and sample‐collection methods that will provide accurate measurement of VOC concentrations in groundwater. This laboratory validation study identified two field‐portable instruments (a gas chromatograph and a photoionization detector) with sufficient sensitivity to measure VOCs in groundwater at concentrations below typical monitoring standards (i.e., 1 to 5 μg/L). The accuracy and precision of these field instruments was sufficient to satisfy typical data‐quality objectives for laboratory‐based analysis. In addition, two sample‐collection methods were identified that yield vapor‐phase samples in equilibrium with water: direct headspace sampling and passive diffusion samplers. These sample‐collection methods allow the field instruments (which measure VOC concentrations in vapor‐phase samples) to be used to measure VOC concentrations in water. After further validation of these sample‐collection methods in the field, this monitoring method will provide a simple way to obtain accurate real‐time measurements of VOC concentrations in groundwater using inexpensive field‐portable analytical instruments. © 2009 Wiley Periodicals, 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.     

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.