Choosing the most effective hazardous waste landfill cover

Determining the appropriate criteria and designs for hazardous waste landfill covers has spawned much discussion within the environmental remediation arena. Very little reliable comparison of various technologies exists. Researchers at Los Alamos National Laboratory studied the relative hydrologic performance of four landfill cover designs—two capillary barrier designs, one modified EPA RCRA design, and one control cover. Monitoring the fate of natural precipitation for nearly four years showed that the covers with barrier layers more effectively reduced deep percolation than the control cover. Although none entirely eliminated deep percolation, the RCRA cover, incorporating a clay hydraulic barrier, most effectively controlled it. The two capillary barriers reduced deep percolation, but significant amounts were still produced. Over 90 percent of all percolation through the covers, and lateral flow within the covers, occurred during February through May each year, primarily as a result of snowmelt, early spring rains, and low evapotranspiration. The study also showed that gravel mulch surface treatments (70- to 80-percent ground cover) reduced runoff and erosion. Despite additional shrubs planted on one, the two plots receiving the gravel mulch treatments exhibited equally enhanced amounts of evapotranspiration.     

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.     

An ecologically oriented database to guide remediation and reuse of contaminated sites

This article presents a database developed to determine the potential reuse of contaminated sites for primarily ecologically and culturally based activities. The database consists of 172 quantitative and qualitative measures of on‐site land suitability, ecological, cultural, and recreational value, and off‐site suitability, economic, and demographic information. Using sites owned by the U.S. Department of Energy (DOE) as a case study, the article evaluates the quality of available data and suggests ways of using it for planning ecologically sensitive remediation activities and future land use. This type of database can be developed and used by anyone who needs to select, review, or evaluate site remediation and future land use options. Also discussed are the challenges associated with compiling and using data that has been generated by many sources over several years. © 2003 Wiley Periodicals, Inc.     

Incorporating ecology and ecological risk into long‐term stewardship on contaminated sites

The long‐term management of environmental contamination will be a major activity at many sites in the foreseeable future. While human health issues often drive decisions about cleanup, restoration, and long‐term stewardship, ecological considerations are also major driving forces and are of paramount importance to the public. Incorporation of ecological considerations into decisions about environmental protection, both short term and long term, requires (1) understanding public perceptions of ecological values, including aesthetics and existence values, (2) understanding contamination issues within a context of the structure and functioning of ecosystems, (3) developing bioindicators of ecological health (including human), (4) developing indicators of ecosystem functioning, and (5) developing and implementing a biomonitoring plan before, during, and after remediation so that adverse effects can be ascertained before they become irreversible. Both remediation/restoration and long‐term stewardship goals must be informed by public policy mandates that include public participation and healthy human and ecological systems. This article examines these issues as they relate to cost‐effective, long‐term protection of human and ecological health on contaminated lands. © 2002 Wiley Periodicals, Inc.     

Managing environmental problems during transitions: The department of energy as a case study

Many federal, state, and private agencies deal with long‐term environmental problems within a transition framework where political administrations, funds, regulators, regulatory requirements, environmental conditions, and tribal and stakeholder concerns change. In this article, we examine the types of transitions, as well as important stabilities, that agencies face, the interactions with stakeholders that are vulnerable to disruption or failure, and some of the problems that develop as a result of these conditions, using the U.S. Department of Energy (US DOE's) Office of Environmental Management (EM) as a case study. Transitions, or instabilities, include changes in administrations at the federal, state, and local level; public perceptions and concerns; political climate; available funds; environmental conditions (e.g., global climate change, global contaminant transport, local and regional contamination); international and national business conditions; and site conditions (physical, chemical, biological). Governmental agencies operate under several different kinds of uncertainties, including scientific, fiscal‐year economic, technological, and societal. Not all information can be known, and the outcomes from scientific issues or technologies cannot always be predicted. The authors believe that transitions from one set of conditions to another can be more effectively integrated with the long‐term stability of environmental laws and regulations, and with the stability of the treaty rights and concerns of tribal nations, as well as the shorter‐term stability of career personnel and established programs. A sense of stability for government agencies allowing maintenance of ongoing environmental management programs can also be achieved through processes and programs, such as establishing long‐term contracts (for remediation or restoration work), schedule and scope documents, future land‐use documents, National Environmental Research Parks (which obligate lands to study and conservation), and other programs that set the direction of work and activities for many years. Further, two other factors are essential for success within any agency facing transitions: (1) expectations should be both forward‐looking and realistic, and (2) there must be flexibility in both programs and processes. The authors conclude that several features are essential to addressing some of the problems created by transitions, including information, integration, iteration, interaction, and inclusion. © 2009 Wiley Periodicals, Inc.     

Initial investigation on the use of waterjets to place amendments in the subsurface

Quasi‐passive in situ remediation technologies, such as the use of permeable reactive barriers to treat contaminated groundwater or applications of granular activated carbon to treat polychlorinated biphenyl (PCB)‐contaminated, near‐surface sediments, are proven or promising technologies that may be limited in application due to the traditional construction techniques normally used for placement in the environment. High‐pressure waterjets have traditionally been used to excavate material during mining operations or to cut rock or other durable material. Waterjets have the potential to place amendments in the subsurface at depths greater than those that can be obtained using traditional construction techniques. Likewise, waterjets may have less negative impact on near‐surface utilities and/or sensitive ecological systems. Laboratory experiments were performed to characterize the placement of two solid amendments in a simulated saturated aquifer. A second set of experiments was performed to characterize the effectiveness of waterjets for placing a third amendment in simulated intertidal sediments. The laboratory work focused on characterizing the nature of the waterjet penetration of the aquifer matrix and the saturated sediments, as well as the corresponding waterjet parameters of pressure, nozzle size, and injection time. The laboratory results suggest that field trials may be appropriate for future investigations. © 2005 Wiley Periodicals, Inc.     

Hazardous Substance Research Centers program: An incubator for remediation research

The Hazardous Substance Research Center (HSRC) was established by the U.S. Environmental Protection Agency (EPA) to assist in the implementation of Superfund and to address major hazardous substance environmental problems at a regional level. Over the past 12 years, the HSRC program has produced more than 1,200 peer‐reviewed technical articles, 27 patents and licenses, 21 new technologies for the remediation marketplace, and provided technical assistance to more than 300 communities. Research, technology transfer, and training are conducted by five regional multi‐university centers, which focus on different aspects of hazardous substance management. Areas of focus include urban environments, contaminated sediments, natural remediation and restoration technologies, abandoned mine lands, and chlorinated solvents in groundwater. This article provides an overview of the five HSRC programs including current areas of research, field studies, and technology transfer Internet links to access research results and remediation technology information. © 2003 Wiley Periodicals, Inc.     

Comparing the Adoption of Contaminated Land Remediation Technologies in the United States,United Kingdom,and China

In many locations across the world, land contamination poses a serious threat to human health and the wider environment. For instance, a report published on April 17, 2014, revealed that China now has 16.1 percent of its land contaminated by various organic and inorganic contaminants, posing a range of challenges from human health risk to food security. The innovation and adoption of suitable remediation technologies is critical for solving land contamination issues. However, little is known about the pattern of remediation technology adoption, as well as its determining factors. This study uses a questionnaire survey in the United States, United Kingdom, and China to examine the spatial variation of remediation technology adoption. It further explores the temporal trend of remediation technology adoption using secondary data from the U.S. Superfund program. The study identified significant differences in remediation technology adoption among these countries, which are attributed to the different environmental, social, economic, and regulatory contexts. It is argued that the full implications of remediation technology adoption to sustainable development should be further studied, and policy instruments should be designed accordingly to promote those remediation technologies that align the best with long‐term sustainability. Technology developers may also use these implications to adjust their research and development priorities. © 2014 Wiley Periodicals, Inc.     

Remediation of uranium-contaminated soil using the segmented gate system and containerized vat leaching techniques: A cost-effectiveness study

Using an innovative, two-stage process to remediate uranium-contaminated soils, researchers at Los Alamos National Laboratory's (LANL's) Technical Area 33 (TA-33) successively reduced 218 cubic yards of contaminated soil to approximately 30 gallons of leachate solution and resins. In the first step, the contaminated soil is separated from the clean soil using the Thermo Nuclean (a division of the Thermo NUtech company) Segmented Gate System (SGS). Contaminated soil proceeds via conveyor belt to a separate storage bin to await further processing, while uncontaminated soil is returned to its original location. From the 218 cubic yards of soil excavated from the test site at TA-33, only seven cubic yards were found to contain uranium contamination above the criterion release limit, yielding an initial waste volume reduction of 97 percent. Using the containerized vat leaching (CVL) method, a technique borrowed from the mining industry, the uranium was then removed from the reduced volume of contaminated soil. This article describes the two processes and analyzes potential cost savings based on different disposal and storage options.     

Yardsticks to Integrate Risk Assessment,Risk Management,and Groundwater Remediation

Remediation of contaminated sites has focused largely on restoration of groundwater aquifers. Often the stated remedial goal is to achieve conditions allowing unrestricted use and unrestricted exposure. Such total groundwater cleanup has occurred at some sites, but is the exception rather than the rule. At the same time, significant effort occurs to perform risk assessments for potential exposure to contaminants in groundwater at sites, both before and after remediation. The logical synergy between risk assessment and remediation is for risk management to seek opportunities for optimal use of groundwater based upon realistic expectations of cleanup technologies and the relevant acceptable residual (postremediation) levels of contaminants. This article explores an approach to improve this synergistic relationship between risk assessment, risk management, and remediation for groundwater cleanups. ©2015 Wiley Periodicals, Inc.     

Best management practices for environmental restoration programs

Based on a review of hundreds of environmental restoration program optimization reviews, this article describes management tools found in successful and efficient remediation programs. Projects that consistently struggled to achieve their objectives were observed to be missing certain, or to have inadequately used, these tools. The tools are articulated as best practices because when they are present and actively used, project shortcomings were minimal. Priority objectives for site owners and project managers include improving efficiency and effectiveness through performance management, reducing resource usage and energy consumption, ensuring protectiveness, and reducing uncertainty in management decision making. Restoring environmental resources damaged by historic waste management practices began in earnest in the late 1960s and early 1970s with the broad recognition of the problems caused by environmental discharges and spills when wastes are not managed appropriately. Under new regulations, soil and groundwater remediation projects could be, and were, conducted within a defined framework. The number and variety of restoration projects that were launched resulted in a slew of projects progressing through the stages of characterization, decision, and cleanup, and more were added to the cleanup process each year. In the 1990s, the Department of Defense noted that many cleanup efforts were projected to incur substantial operational, maintenance, and monitoring costs for decades into the future. This was correctly perceived as an opportunity to optimize those systems and programs, minimize costs, and reduce health and environmental risks. The best practices outlined in this article address management tools that were identified in optimization efforts that led to effective and efficient environmental remediation projects. © 2010 Wiley Periodicals, Inc.     

A conceptual cost estimate for remediation activities at a multisite federal facility

The Sandia National Laboratories Environmental Restoration Project is in the process of determining the nature and extent of environmental contamination at numerous potential release sites. Sites found to be contaminated above certain action levels must be remediated. Sandia is responsible for preparing preliminary cost estimates for remediation activities in order to meet Department of Energy planning requirements for future funding. Sandia used the ENVEST parametric cost-estimating model to prepare conceptual cost estimates for remediation prior to having definitive knowledge of the nature and extent of contamination. This article describes the estimating approach and the results achieved at Sandia.     

Remediation of the Radioactive Waste Landfill and Chemical Disposal Pits Sites at Sandia National Laboratories

Sandia National Laboratories' Environmental Restoration (ER) Project remediated the Radioactive Waste Landfill and Chemical Disposal Pits (RWL/CDPs) sites located in Albuquerque, New Mexico. The remediation was conducted in 1996 using conventional excavation, as well as hybrid remote robotic manipulation technology at a cost of approximately $3 million. Wastes generated included approximately 73 cubic meters (m³) of debris (including thermal batteries, spark gap tubes, radioactive sources, weapons components, and some classified material), 535 m³ of plutonium-contaminated soil, and 2,294 m³ of soil contaminated with thorium, cesium, uranium, and tritium. The remediation was successful since the project goal of risk reduction was accomplished and no injuries or negative occurrences resulted. This cleanup is one example of the Department of Energy's (DOE's) accelerated approach to environmental restoration. The remediation was performed as a voluntary corrective measure to reduce schedule and budget, compared with the traditional approach following Resource Conservation and Recovery Act (RCRA) regulations.     

Institutional controls for future land use at active installation restoration program (IRP) sites

One of the strategies now in vogue in hazardous waste cleanup is basing remedial strategies on future land use. The initial thrust of CERCLA for permanent and complete remedies has given way, pushed by concepts like “brownfields” and base closure and reuse, to strategies often based on “institutional controls” that attempt to stabilize future land uses at a site based on residual risk. The heart of this concept is that instead of removing all wastes from a site, some wastes can safely remain so long as in the future the site is not used in such a way that the residual contamination poses an unacceptable risk to human health and the environment. “Institutional controls” is a term for land use management strategies that do not rely on engineering approaches to reduce risk, but rather seek to ensure that the site is not used in an inappropriate way in the future. This article cautions that such a strategy has inherent residual risks that must be understood by those involved in implementing hazardous waste cleanups and those responsible for future uses of contaminated property. Simply put, institutional controls are only as good as the processes that are in place to ensure they are respected in the future. This presents particular problems for active duty installations because most of the protections commonly available to private sector sites are not useful at active installations. This article discusses an initiative by the Air Combat Command to develop a handbook on instituting and maintaining land restrictions. It will also discuss that effort in light of the April 21 EPA Region IV guidance on assuring Land Use Controls at Federal Facilities. This article is based on a paper and presentations given at the 1998 ACC Environmental Training Symposium.     

Radiological risks and cleanup costs: A remediation case study

Potential health risks and cleanup costs are primary factors for measuring the effectiveness of a remediation project concerning a site contaminated with residual radioactive materials. Demanding cleanup of a contaminated site to its original condition, while eliminating any health risks after cleanup, can require prohibitive costs. However, by setting practical remediation objectives and by performing realistic but conservative risk assessments, health risks can be acceptable and cleanup costs can be reasonable. This article uses the South-Middle and Southeast Vaults Decontamination and Demolition Project at Argonne National Laboratory to demonstrate how negligible health risks can result after cleanup with minimal cleanup costs. Substantial cost savings of approximately $2 million was realized by implementing in-place decontamination and demolition (D&D) on the basis of acceptable risk, instead of requiring cleanup of the site to its original condition. By using the RESRAD computer program as a modeling tool, we show the maximum projected radiation dose (0.1 mrem per year) and the potential lifetime cancer risk (on the order of 10⁶) to an individual from exposure to the residual radioactivities are negligibly small. In addition to aiding in the selection of a preferred remediation alternative, results of the RESRAD modeling were also used to guide the implementation of the selected alternative to reduce exposures from the dominant pathway and to ensure that exposures from all pathways would be as low as reasonably achievable.     

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.     

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.     

Transuranic waste remediation in Idaho: Pit 9, failed contracts,and lawsuits

The U.S. Department of Energy (US DOE) remediation responsibilities include its Idaho National Laboratory. In 1989, the U.S. Environmental Protection Agency placed the Idaho site on its National Priority List for environmental cleanup. The site's contamination legacy from operations included inactive reactors and other structures, spent nuclear fuel, high‐level liquid radioactive wastes, calcined radioactive wastes, and transuranic wastes. Documents governing cleanup include a 1995 Settlement Agreement between the US DOE and the US Navy as responsible parties, and the State of Idaho. The Subsurface Disposal Area contains buried transuranic wastes, lies above the East Snake River Plain Aquifer, and could be the “site's most nettlesome cleanup issue,” according to an outside observer. This article describes the technical and legal difficulties that have been encountered in remediating this area. © 2010 Wiley Periodicals, Inc.     

A Case Study of the Beneficial Reuse of Treated Groundwater

The future disposal of treated groundwater at the former Nebraska Ordnance Plant (NOP) Superfund site has been a topic of interest to the local property owners, the U.S. Army Corps of Engineers, and the local regulatory agencies. The Record of Decision for the site includes the extraction, treatment, and disposal of almost 3,000 gpm of groundwater with an estimated restoration time period exceeding 100 years. Interest from property owners and the Nebraska agency charged with regulating groundwater supply prompted the Corps of Engineers to consider several strategies for beneficially reusing the treated water. Alternatives included the establishment of a rural water district or local distribution system; delivery of the water to the municipal supply system of Lincoln, Nebraska, andsol;or other nearby municipalities; and consideration of innovative remedial technologies to reduce the quantity of treated water requiring disposal. The selected disposal plan consists of providing treated groundwater to interested parties for agricultural use with excess treated groundwater discharged to two streams. Multiple feasibility studies were generated, public input was solicited, and interagency agreements were executed during the course of the project. The remediation project is currently being constructed, and at least one property owner has constructed a new center‐pivot irrigation system to use the treated groundwater. © 2001 John Wiley & Sons.