Approaches for assessing hazards and risks to workers and the public from contaminated land

Many public agencies and private entities are faced with assessing the risks to humans from contamination on their lands. The United States Department of Energy (US DOE) and Department of Defense are responsible for large holdings of contaminated land and face a long‐term and costly challenge to assure sustainable protectiveness. With increasing interest in the conversion of brownfields to productive uses, many former industrial properties must also be assessed to determine compatible future land uses. In the United States, many cleanup plans or actions are based on the Comprehensive Environmental Responsibility, Compensation, and Liability Act, which provides important but incomplete coverage of these issues, although many applications have tried to involve stakeholders at multiple steps. Where there is the potential for exposure to workers, the public, and the environment from either cleanup or leaving residual contamination in place, there is a need for a more comprehensive approach to evaluate and balance the present and future risk(s) from existing contamination, from remediation actions, as well as from postremediation residual contamination. This article focuses on the US DOE, the agency with the largest hazardous waste remediation task in the world. Presented is a framework extending from preliminary assessment, risk assessment and balancing, epidemiology, monitoring, communication, and stakeholder involvement useful for assessing risk to workers and site neighbors. Provided are examples of those who eat fish, meat, or fruit from contaminated habitats. The US DOE's contaminated sites are unique in a number of ways: (1) huge physical footprint size, (2) types of waste (mixed radiation/chemical), and (3) quantities of waste. Proposed future land uses provide goals for remediation, but since some contamination is of a type or magnitude that cannot be cleaned up with existing technology, this in turn constrains future land use options, requiring an iterative approach. The risk approaches must fit a range of future land uses and end‐states from leave‐in‐place to complete cleanup. This will include not only traditional risk methodologies, but also the assessment and surveillance necessary for stewards for long‐term monitoring of risk from historic and future exposure to maintain sustainable protectiveness. Because of the distinctiveness of DOE sites, application of the methodologies developed here to other waste site situations requires site‐specific evaluation © 2007 Wiley Periodicals, Inc.     

Application of source removal and natural attenuation remediation strategies at MGP sites in Wisconsin

This article presents site closure strategies of source material removal and dissolved‐phase groundwater natural attenuation that were applied at two manufactured gas plant (MGP) sites in Wisconsin. The source removal actions were implemented in 1999 and 2000 with groundwater monitoring activities preceding and following those actions. Both of these sites have unique geological and hydrogeological conditions. The article briefly presents site background information and source removal activities at both of these sites and focuses on groundwater analytical testing data that demonstrate remediation of dissolved‐phase MGP‐related groundwater impacts by natural attenuation. A statistical evaluation of the data supports a stable or declining MGP parameter concentration trend at each of the sites. A comparison of the site natural attenuation evaluation is made to compare with the requirements for site closure under the Wisconsin Department of Natural Resources regulations and guidance. © 2003 Wiley Periodicals, Inc.     

Integrating Remediation and Reuse to Achieve Whole‐System Sustainability Benefits

This perspective article was prepared by members of the Sustainable Remediation Forum (SURF), a professional nonprofit organization seeking to advance the state of sustainable remediation within the broader context of sustainable site reuse. SURF recognizes that remediation and site reuse, including redevelopment activities, are intrinsically linked—even when remediation is subordinate to or sometimes a precursor of reuse. Although the end of the remediation life cycle has traditionally served as the beginning of the site's next life cycle, a disconnect between these two processes remains. SURF recommends a holistic approach that brings together remediation and reuse on a collaborative parallel path and seeks to achieve whole‐system sustainability benefits. This article explores the value of integrating remediation into the reuse process to fully exploit synergies and minimize the costs and environmental impacts associated with bringing land back into beneficial use. © 2013 Wiley Periodicals, Inc.     

Removal,Handling, and Thermal Desorption Treatment Techniques for Manufactured Gas Plant Wastes

Due to the nature of contamination typically found at former MGP (manufactured gas plant) sites, excavation and thermal desorption of MGP wastes has proven to be an effective method for the remediation of MGP‐contaminated soil. The use of on‐site thermal desorption enables MGP sites to be quickly remediated at a low cost. Tar pits, holders, and other underground storage structures typically contain coal tar residuals and waste from former operations, and the areas around these structures are often significantly contaminated. Thus, excavation techniques, odor and vapor management, and material preparation for the treatment method are important factors to consider when developing a site remediation strategy. This article reviews typical excavation and handling methods associated with the remediation of former MGP sites and discusses the treatment of MGP wastes using on‐site thermal desorption technology. © 2001 John Wiley & Sons, Inc.     

Integrating multi-criteria decision analysis for a GIS-based hazardous waste landfill sitting in Kurdistan Province, western Iran

The evaluation of a hazardous waste disposal site is a complicated process because it requires data from diverse social and environmental fields. These data often involve processing of a significant amount of spatial information which can be used by GIS as an important tool for land use suitability analysis. This paper presents a multi-criteria decision analysis alongside with a geospatial analysis for the selection of hazardous waste landfill sites in Kurdistan Province, western Iran. The study employs a two-stage analysis to provide a spatial decision support system for hazardous waste management in a typically under developed region. The purpose of GIS was to perform an initial screening process to eliminate unsuitable land followed by utilization of a multi-criteria decision analysis (MCDA) to identify the most suitable sites using the information provided by the regional experts with reference to new chosen criteria. Using 21 exclusionary criteria, as input layers, masked maps were prepared. Creating various intermediate or analysis map layers a final overlay map was obtained representing areas for hazardous waste landfill sites. In order to evaluate different landfill sites produced by the overlaying a landfill suitability index system was developed representing cumulative effects of relative importance (weights) and suitability values of 14 non-exclusionary criteria including several criteria resulting from field observation. Using this suitability index 15 different sites were visited and based on the numerical evaluation provided by MCDA most suitable sites were determined.     

Solidification/stabilization for remediation of wood preserving sites: Treatment for dioxins,PCP, creosote,and metals

This article discusses the use of solidification/stabilization (S/S) to treat soils contaminated with organic and inorganic chemicals at wood preserving sites. Solidification is defined for this article as making a material into a freestanding solid. Stabilization is defined as making the contaminants of concern nonmobile as determined from a leaching test. S/S then combines both properties. For more information on S/S in general the reader should refer to other publications (Connors, J.R. [1990]). Chemical fixation and solidification of hazardous wastes. New York: Van Nostrand Reinhold; US Environmental Protection Agency. [1993a]. Engineering bulletin solidification/stabilization of organics and inorganics (EPA/540/S‐92/015); Wiles, C.C. [1989]. Solidification and stabilization technology. In H.M. Freeman [Ed.], Standard handbook of hazardous waste treatment and disposal. New York: McGraw Hill) as this article addresses only wood preserving sites and assumes basic knowledge of S/S processes. For a more general discussion of wood preserving sites and some other remedial options, the reader may wish to refer to a previous EPA publication (US Environmental Protection Agency. [1992a]. Contaminants and remedial options at wood preserving sites [EPA/600/R‐92/182]). This article includes data from the successful remediation of a site with mixed organic/inorganic contaminants, remediation of a site with organic contaminants, and detailed treatability study results from four sites for which successful formulations were developed. Included are pre‐ and post‐treatment soil characterization data, site vaines. ileizdot‐ names (in some cases), treatment formulas used (generic aridproprietary), costs, recommendations, and citatioiis to inore detailed refer‐ en ces. The data presen ted iiidica te that dioxins, pentachlorophepi 01 (PCP), creosote, polycyclic aromatic hydrocarbom (PAHsI, and metals can be treated at moderate cost by the use of S/S techuologp.     

Study of the future land use of a contaminated site: Preferences versus potential use

Worldwide, agencies with high levels of contamination are faced with decisions about remediation and restoration. These decisions should be informed by future land use and long‐term stewardship goals. In the United States, the Department of Energy has lands in some 34 states that require cleanup. They are involved in massive remediation and restoration efforts on lands from the Cold War legacy and wish to reduce their overall footprint. Understanding future land use preferences is essential for determining the nature and degree of remediation and restoration. The objective of this study was to examine future land use preferences for the Department of Energy's Los Alamos National Laboratory as a function of ethnicity for attendees at the Los Alamos Gun Show in New Mexico (1999), and to determine whether their own activity influences future land use preferences. The highest preferred future land uses for Los Alamos National Laboratory were hiking, camping, National Environmental Research Park, and birdwatching, followed by hunting and fishing. Increased nuclear waste storage and building homes and factories were rated the lowest. Further, hiking and camping were rated higher than at two other DOE sites. There were few ethnic differences, although American Indians rated camping, hiking, building houses, and returning the land to American Indians higher than did others, and Hispanics rated using it for a preserve as a higher preferred land use than all others. The differences, however, were not great. Relative ratings for using the land for hunting and fishing were directly related to individual frequency of hunting and fishing for both whites and Hispanics, indicating that people perceive the importance of land use by how they want to use it. Ratings for hiking and camping were not related to the number of days people hiked and camped, suggesting these are general preferences overall. © 2004 Wiley Periodicals, Inc.     

Applying sustainable development principles to contaminated land management using the SuRF‐UK framework

In the past decade, management of historically contaminated land has largely been based on prevention of unacceptable risks to human health and the environment, to ensure a site is “fit for use.” More recently, interest has been shown in including sustainability as a decision‐making criterion. Sustainability concerns include the environmental, social, and economic consequences of risk management activities themselves, and also the opportunities for wider benefit beyond achievement of risk‐reduction goals alone. In the United Kingdom, this interest has led to the formation of a multistakeholder initiative, the UK Sustainable Remediation Forum (SuRF‐UK). This article presents a framework for assessing “sustainable remediation”; describes how it links with the relevant regulatory guidance; reviews the factors considered in sustainability; and looks at the appraisal tools that have been applied to evaluate the wider benefits and impacts of land remediation. The article also describes how the framework relates to recent international developments, including emerging European Union legislation and policy. A large part of this debate has taken place in the “grey” literature, which we review. It is proposed that a practical approach to integrating sustainability within risk‐based contaminated land management offers the possibility of a substantial step forward for the remediation industry, and a new opportunity for international consensus. © 2011 Wiley Periodicals, Inc.     

Developing Effective Decision Support for the Application of “Gentle” Remediation Options: The GREENLAND Project

Gentle remediation options (GRO) are risk management strategies/technologies that result in a net gain (or at least no gross reduction) in soil function as well as risk management. They encompass a number of technologies, including the use of plant (phyto‐), fungi (myco‐), and/or bacteria‐based methods, with or without chemical soil additives or amendments, for reducing contaminant transfer to local receptors by in situ stabilization, or extraction, transformation, or degradation of contaminants. Despite offering strong benefits in terms of risk management, deployment costs, and sustainability for a range of site problems, the application of GRO as practical on‐site remedial solutions is still in its relative infancy, particularly for metal(loid)‐contaminated sites. A key barrier to wider adoption of GRO relates to general uncertainties and lack of stakeholder confidence in (and indeed knowledge of) the feasibility or reliability of GRO as practical risk management solutions. The GREENLAND project has therefore developed a simple and transparent decision support framework for promoting the appropriate use of gentle remediation options and encouraging participation of stakeholders, supplemented by a set of specific design aids for use when GRO appear to be a viable option. The framework is presented as a three phased model or Decision Support Tool (DST), in the form of a Microsoft Excel‐based workbook, designed to inform decision‐making and options appraisal during the selection of remedial approaches for contaminated sites. The DST acts as a simple decision support and stakeholder engagement tool for the application of GRO, providing a context for GRO application (particularly where soft end‐use of remediated land is envisaged), quick reference tables (including an economic cost calculator), and supporting information and technical guidance drawing on practical examples of effective GRO application at trace metal(loid) contaminated sites across Europe. This article introduces the decision support framework. ©2015 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.     

In Situ Solidification (ISS) of River Sediments: Pilot Demonstration and Discussion of ISS as a Remedial Alternative to Dredging and Capping

In situ solidification (ISS) is a proven technology for remediation of upland site soils, but has not been thoroughly demonstrated for use in impacted underwater sediments. This article describes the first successful use of ISS techniques to solidify underwater sediments containing manufactured gas plant non‐aqueous‐phase liquid (NAPL). The techniques consisted of mixing cementitious grout with the sediments in situ to create a monolith that immobilized the contaminants, significantly decreased the hydraulic conductivity, and also vastly decreased contaminant leaching potential of the sediments. The success of this pilot demonstration project suggests that ISS may be a viable alternative for: sites requiring deep dredging; large volume projects on urban waterways where staging and amending areas are limited; sites with NAPL impacts that cannot be controlled during dredging; and sites where eventual NAPL breakthrough is anticipated if reactive caps are employed. The potential economic, environmental, and operational benefits of this technology will be discussed. This article focuses on the primary objectives of the pilot demonstration: to meet quantitative performance criteria for strength and hydraulic conductivity; to assess the leach performance of the solidified sediments; and to satisfy water quality parameters for turbidity, pH, and sheen. Approach/activities: The pilot study utilized a customized marine platform (modular floats, tug boats, etc.) and full‐scale ISS equipment (auger rig, silos, etc.) and varied operational parameters to provide a range of data to assist in evaluating the feasibility and efficacy of the technology for use in similar environments and in planning future ISS projects on the water. Water quality controls and monitoring were implemented during the operation, and the study documented and evaluated the environmental disruption (short‐term impacts) and costs of the application of the ISS process to contaminated aquatic sediments. ©2016 Wiley Periodicals, Inc.     

Nanotechnology for site remediation

As a remediation tool, nanotechnology holds promise for cleaning up hazardous waste sites cost‐effectively and addressing challenging site conditions, such as the presence of dense nonaqueous phase liquids (DNAPLs). Some nanoparticles, such as nanoscale zero‐valent iron (nZVI) are already in use in full‐scale projects with encouraging success. Ongoing research at the bench and pilot scale is investigating particles such as self‐assembled monolayers on mesoporous supports (SAMMS™), dendrimers, carbon nanotubes, and metalloporphyrinogens to determine how to apply their unique chemical and physical properties for full‐scale remediation. There are many unanswered questions regarding nanotechnology. Further research is needed to understand the fate and transport of free nanoparticles in the environment, whether they are persistent, and whether they have toxicological effects on biological systems. In October 2008, the U.S. Environmental Protection Agency's Office of Superfund Remediation and Technology Innovation (OSRTI) prepared a fact sheet entitled “Nanotechnology for Site Remediation,” and an accompanying list of contaminated sites where nanotechnology has been tested. The fact sheet contains information that may assist site project managers in understanding the potential applications of this group of technologies. This article provides a synopsis of the US EPA fact sheet, available at http://clu‐in.org/542F08009 , and includes background information on nanotechnology; its use in site remediation; issues related to fate, transport, and toxicity; and a discussion of performance and cost data for field tests. The site list is available at http://clu‐in.org/products/nanozvi . © 2008 Wiley Periodicals, Inc.     

Nature,frequency, and cost of environmental remediation at onshore oil and gas exploration and production sites

This article quantifies the nature, frequency, and cost of environmental remediation activities for onshore oil and gas operations, as determined from over 4,100 environmental remediation cases in Texas, Kansas, New Mexico, and Colorado. For the purpose of this article, “remediation'' refers to cleanup efforts that entail longer‐term site characterization, monitoring, and remedial action beyond the initial spill cleanup or emergency response stage. In addition, data are also presented regarding short‐term spill cleanup activities in two of the four states. © 2011 Wiley Periodicals, Inc.     

Trends In Regulatory Acceptance Of Risk-Based Cleanup Goals And Natural Attenuation For Site Closure

Since 1994, there has been a significant regulatory shift toward risk-based cleanup standards based on the site-specific risk of the more toxic and mobile compounds; namely, benzene, ethyl benzene, toluene, and xylene (BTEX). This regulatory shift has been accompanied by a growing acceptance of natural attenuation as an important component of petroleum site remediation. This article briefly reviews regulatory progress toward risk-based remediation and describes the successful application of risk-based corrective actions (RBCAs) at two fuel contaminated sites on Air Force installations. By developing site-specific cleanup goals, and combining natural attenuation, source reduction, and land use controls, innovative risk-based closure plans have been implemented on these sites.     

Injecting remediation compounds—How you inject is equally as important as what you inject

The injection of remediation compounds has rapidly become a widely accepted approach for addressing contaminated sites. One of the most fundamental questions surrounding the use of in situ remediation has been “What compound are you injecting at your site?” With the advances in the industry's understanding and acceptance of the in situ remediation process remediation professionals are now asking a follow‐up question that has become equally important to the success of a project: “How are you injecting a compound at your site?” This article discusses advances in field applications for in situ remediation and injecting remediation compounds. © 2003 Wiley Periodicals, Inc.     

Managing contaminated sites and the role of domestic and international forums

Domestic and international cooperation in the field of contaminated‐site management has increased dramatically in the past decade. The expected benefits of this cooperation include the reduction of duplication in remediation efforts, the coordination of contaminated‐site research, improved synergy between various stakeholders, enhanced policy development, and better information dissemination and technology transfer. This article identifies and briefly discusses key domestic and international collaborations, partnerships, and networks relating to contaminated‐site management and remediation. Also provided is information on how the forums can be accessed. Common themes identified across the forums discussed in this article include (1) the development and demonstration of innovative technologies, (2) the use of risk assessment, (3) the use of toxicology, bioavailability, and ecotoxicity testing, and (4) the increasing need to find holistic approaches for managing contaminated sites, such as guaranteed remediation programs and transfer of environment liability, and the need for understanding implications of remediation financing mechanisms. © 2001 John Wiley & Sons, Inc.     

A needs analysis method for land-use planning of illegal dumping sites: A case study in Aomori–Iwate,Japan

Land use at contaminated sites, following remediation, is often needed for regional redevelopment. However, there exist few methods of developing economically and socially feasible land-use plans based on regional needs because of the wide variety of land-use requirements. This study proposes a new needs analysis method for the conceptual land-use planning of contaminated sites and illustrates this method with a case study of an illegal dumping site for hazardous waste. In this method, planning factors consisting of the land-use attributes and related facilities are extracted from the potential needs of the residents through a preliminary questionnaire. Using the extracted attributes of land use and the related facilities, land-use cases are designed for selection-based conjoint analysis. A second questionnaire for respondents to the first one who indicated an interest in participating in the second questionnaire is conducted for the conjoint analysis to determine the utility function and marginal cost of each attribute in order to prioritize the planning factors to develop a quantitative and economically and socially feasible land-use plan. Based on the results, site-specific land-use alternatives are developed and evaluated by the utility function obtained from the conjoint analysis. In this case study of an illegal dumping site for hazardous waste, the uses preferred as part of a conceptual land-use plan following remediation of the site were (1) agricultural land and a biogas plant designed to recover energy from biomass or (2) a park with a welfare facility and an athletic field. Our needs analysis method with conjoint analysis is applicable to the development of conceptual land-use planning for similar sites following remediation, particularly when added value is considered.     

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.     

Advanced site diagnostic tool 3D‐CSIA for in situ remediation

In situ remediation is inherently considered “green remediation.” The mechanisms of destruction by in situ technologies, however, are often unseen and not well understood. Further, physical effects of amendment application affect concentration data in an identical manner as the desired reactive mechanism. These uncertainties have led to the weight‐of‐evidence approach when proving viability: multiple rounds of data collection, bench studies, pilot studies, and so on. Skipping these steps has resulted in many failed in situ applications. Traditional assessment data are often tangential to the desired information (e.g., “Is contaminant being destroyed or just being pushed around and diluted?” and “What is the mechanism of the destruction and can it be monitored directly?”). An advanced site diagnostic tool, “Three‐Dimensional Compound Specific Stable Isotope Analysis” (3D‐CSIA), can assess the viability of in situ technologies by providing definitive data on contaminant destruction that are not concentration‐related. The 3D‐CSIA tool can also locate source zones and apportion remediation cost by identifying plumes of different isotope signatures and fractionation trends. Further, use of the 3D‐CSIA tool allows remediation professionals to evaluate effectiveness of treatment and make better decisions to expedite site closure and minimize costs. This article outlines the fundamentals of advanced site diagnostic tool 3D‐CSIA in detail, and its benefit is highlighted through a series of case studies at chlorinated solvent–contaminated sites. © 2010 Wiley Periodicals, Inc.