A Technicoeconomic Approach for theSelection of a Site Remediation Strategy—Part B: Model Application

Different tools, such as a screening matrix or decision framework, are available to select a remediation technology to treat a contaminated site. However, unless these methods can point out the appropriate technology in regards to the decision-maker's knowledge about the contaminated site, they are less useful to evaluate both the technical effectiveness and the cost of the remediation, and to assess different remediation strategies from either future data acquisition or the use of an irreversible remediation technology. A model developed to allow such evaluations has been used to simulate the remediation of a virtual contaminated site. From this, four remediation recommendations have been made. These recommendations are guidelines for the build up of a remediation strategy that would both maximize the effectiveness of the decontamination and minimize its total cost.     

A technicoeconomic approach for the selection of a site remediation strategy--part B: model application

Different tools, such as a screening matrix or decision framework, are available to select a remediation technology to treat a contaminated site. However, unless these methods can point out the appropriate technology in regards to the decision-maker's knowledge about the contaminated site, they are less useful to evaluate both the technical effectiveness and the cost of the remediation, and to assess different remediation strategies from either future data acquisition or the use of an irreversible remediation technology. A model developed to allow such evaluations has been used to simulate the remediation of a virtual contaminated site. From this, four remediation recommendations have been made. These recommendations are guidelines for the build up of a remediation strategy that would both maximize the effectiveness of the decontamination and minimize its total cost.     

A technicoeconomic approach for the selection of a site remediation strategy--part A: theory

A technicoeconomic model is developed to select an optimal strategy for the remediation of a contaminated site and to determine the value of this remediation strategy. The model is an extension of actual cost-benefit analysis, with consideration of "irreversible" remediation technology choices, technology effectiveness, and uncertainty on the site's level of contamination. The model considers the possibility of reducing uncertainty by both acquiring more and better information on the level of contamination and by offering the decision-maker the opportunity to reevaluate his decision and switch to a more appropriate technology. It is believed that this model will help decision-makers in the selection of a remediation strategy by presenting all potentially feasible strategies, and how uncertainty on the site's level of contamination affects these strategies.     

Remediation of contaminated lands: a decision methodology for site owners

Deciding how to remediate and redevelop contaminated lands should involve more than just selecting remediation techniques to clean a site to meet regulations for a predetermined site use. Owners and their consultants also need to understand aspects such as alternative site uses and liability, and how issues such as uncertainty can affect them. A methodology has been developed that provides a framework for current site owners when making decisions. It clarifies the above issues and details the type of information that is needed. It offers a step-by-step approach to improve decision making when contemplating remediation of contaminated sites by identifying the site use and remedial action combination that maximizes the current owner's net benefits. It examines various factors in decision making--with special emphasis on the timely issues of liability and uncertainty--and how expert opinion can be used to address diverse or incomplete data. Future research should include developing a complementary methodology that incorporates community and ecological objectives, resulting in a unified decision framework.     

A Technicoeconomic Approach for the Selection of a Site Remediation Strategy—Part A: Theory

A technicoeconomic model is developed to select an optimal strategy for the remediation of a contaminated site and to determine the value of this remediation strategy. The model is an extension of actual cost–benefit analysis, with consideration of “irreversible” remediation technology choices, technology effectiveness, and uncertainty on the site's level of contamination. The model considers the possibility of reducing uncertainty by both acquiring more and better information on the level of contamination and by offering the decision-maker the opportunity to reevaluate his decision and switch to a more appropriate technology. It is believed that this model will help decision-makers in the selection of a remediation strategy by presenting all potentially feasible strategies, and how uncertainty on the site's level of contamination affects these strategies.     

Cost‐benefit analysis of soil remediation in Israeli industrial zones

Industrial zones are the main source of soil pollution in Israel. Due to the upcoming approval of the bill on soil contamination and remediation in Israel, it is important to assess the economic feasibility of soil remediation. This study examines the economic feasibility of an extensive remediation project of all contaminated industrial zones in Israel. The estimated economic benefits include both direct benefits, resulting from the increase in the land value of the contaminated site, and indirect benefits, arising from the increase in nearby property values. A cost‐benefit analysis showed a cost benefit ratio of 1:14. Nonetheless, the direct benefits were found to be lower than the costs. Thus, the question of funding requires collaboration between government and the private sector.     

气候变化视角下的污染场地绿色可持续修复新方向

全球气候变化背景下,绿色可持续修复已成为修复领域的必然趋势。极端天气频发和水文条件改变等气候变化会影响污染场地修复工程实施和修复技术适用性等,绿色可持续修复亟待进一步发展和完善。弹性修复是在绿色可持续修复的基础上,进一步应对和适应气候变化的新兴修复方向。英美等发达国家已经初步发展了弹性修复的理论和实践,本文通过探究污染场地修复与气候变化的交互作用,借鉴发达国家的相关经验和实践案例,为我国污染场地绿色可持续修复适应气候变化提出发展建议。     

Statistical evaluation of geochemical parameter distribution in a ground water system contaminated with petroleum hydrocarbons

A shallow-depth ground water area was investigated to identify the dominant processes governing the distribution of hydrocarbon contaminants and hydrogeochemical parameters. The ground water in the study site has been highly contaminated with petroleum hydrocarbons. A preliminary pump-and-treatment remediation technology was applied for 4 yr at the site. Multivariate analyses were applied to hydrogeochemical data obtained before and after the rainy season. The pump-and-treatment application, indigenous biodegradation, and mixing by precipitation recharge are the major factors or events involved in the distribution of geochemical parameters of the ground water in the study area. Site-specific artificial pavement also played an important role in the evolution of the ground water chemistry. A conventional graphical analysis method (Piper plot) of major ions did not effectively reveal these effects. In this study, we demonstrate the usefulness of multivariate analysis (factor and cluster analyses) using biodegradation indicator parameters, as well as major cations and anions, for the study of the ground water system in the hydrocarbon-contaminated site.     

A Proactive Approach Can Make Site Remediation Less Expensive

Without any incentive to clean up a contaminated site, remediation is often delayed until the site owner is compelled to act by regulatory agencies. In such a context, the selected technology is typically the one that will reach the remediation goals as quickly as possible. Unfortunately, this criterion is often met by overly expensive technologies, resulting in high and sometimes unaffordable total remediation costs, leading to a remediation with a negative net benefit. This study examines the effects of time constraint and benefit value on the optimal remediation strategy for a diesel-contaminated site. This strategy is developed using the technico-economic model METEORS, which takes into account the technology’s effectiveness, the uncertainty of the level of contamination, and the possibility of reducing this uncertainty through either an additional characterization (before selecting and applying a technology) or the monitoring of the remediation technology (during its use). Results of simulations with both economic and temporal constraints support a proactive approach to site remediation.     

A Framework for Net Environmental Benefit Analysis for Remediation or Restoration of Contaminated Sites

Net environmental benefits are gains in value of environmental services or other ecological properties attained by remediation or ecological restoration minus the value of adverse environmental effects caused by those actions. Net environmental benefit analysis (NEBA) is a methodology for comparing and ranking net environmental benefits associated with multiple management alternatives. A NEBA for chemically contaminated sites typically involves comparison of several management alternatives: (1) leaving contamination in place; (2) physically, chemically, or biologically remediating the site through traditional means; (3) improving ecological value through onsite and offsite restoration alternatives that do not directly focus on removal of chemical contamination; or (4) a combination of those alternatives. NEBA involves activities that are common to remedial alternatives analysis for state regulations and the Comprehensive Environmental Response, Compensation, and Liability Act, post-closure and corrective action permits under the Resource Conservation and Recovery Act, evaluation of generic types of response actions pertinent to the Oil Pollution Act, and land management actions that are negotiated with regulatory agencies in flexible regulatory environments (i.e., valuing environmental services or other ecological properties, assessing adverse impacts, and evaluating remediation or restoration options). This article presents a high-level framework for NEBA at contaminated sites with subframeworks for natural attenuation (the contaminated reference state), remediation, and ecological restoration alternatives. Primary information gaps related to NEBA include nonmonetary valuation methods, exposure–response models for all stressors, the temporal dynamics of ecological recovery, and optimal strategies for ecological restoration.Published online     

Eco-efficiency in contaminated land management in Finland – Barriers and development needs

In Finland the number of potentially contaminated sites totals ca. 20?000. The annual costs of remediation are 60–70 million euros. Excavation combined with disposal or off-site treatment is the most common soil remediation method. To define which factors make contaminated land management (CLM) eco-efficient and to study whether eco-efficiency has been considered in CLM decisions we carried out a literature survey, two stakeholder seminars, thematic interviews and a questionnaire study on economic instruments. Generally speaking, eco-efficiency means gaining environmental benefits with fewer resources. To assess its realization in CLM, it is necessary to have a more specific definition. In our study, we arrived at a list of several qualifications for eco-efficiency. It was also shown that eco-efficiency has hardly been a real issue in the selection of remediation techniques or generally, in the decision-making concerning contaminated sites. The existing policy instruments seem to be insufficient to promote eco-efficiency in CLM. Several concrete barriers to eco-efficiency also came up, urgency and lack of money being the most important. The scarcity of the use of in situ remediation methods and the difficulties involved in recycling slightly contaminated or treated soil were considered to be major problems. Insufficient site studies, inadequate or unsuitable methods for risk assessment and cost evaluation, and deficient and mistimed risk communication can also hinder the realization of eco-efficiency. Hence, there is a need to promote the use of more eco-efficient remediation techniques and to develop CLM policy instruments, guidelines, and participatory processes and methods to assess the eco-efficiency of CLM options.     

污染土壤淋洗修复技术研究进展

本文介绍了淋洗修复技术和淋洗装置在污染土壤修复技术中的应用,对有机物、重金属及放射性核素污染土壤淋洗修复技术的应用现状进行了总结和评价,还探讨了淋洗修复技术的发展方向及其应用前景。     

Risk-based economic decision analysis of remediation options at a PCE-contaminated site

Remediation methods for contaminated sites cover a wide range of technical solutions with different remedial efficiencies and costs. Additionally, they may vary in their secondary impacts on the environment i.e. the potential impacts generated due to emissions and resource use caused by the remediation activities. More attention is increasingly being given to these secondary environmental impacts when evaluating remediation options. This paper presents a methodology for an integrated economic decision analysis which combines assessments of remediation costs, health risk costs and potential environmental costs. The health risks costs are associated with the residual contamination left at the site and its migration to groundwater used for drinking water. A probabilistic exposure model using first- and second-order reliability methods (FORM/SORM) is used to estimate the contaminant concentrations at a downstream groundwater well. Potential environmental impacts on the local, regional and global scales due to the site remediation activities are evaluated using life cycle assessments (LCA). The potential impacts on health and environment are converted to monetary units using a simplified cost model.A case study based upon the developed methodology is presented in which the following remediation scenarios are analyzed and compared: (a) no action, (b) excavation and off-site treatment of soil, (c) soil vapor extraction and (d) thermally enhanced soil vapor extraction by electrical heating of the soil. Ultimately, the developed methodology facilitates societal cost estimations of remediation scenarios which can be used for internal ranking of the analyzed options. Despite the inherent uncertainties of placing a value on health and environmental impacts, the presented methodology is believed to be valuable in supporting decisions on remedial interventions.     

推动土壤污染修复产业可持续发展的思考

土壤污染修复产业是环保产业新一轮发展的重点,其市场规模在未来可能是千亿级或万亿级。我国土壤污染修复产业发展面临要素支撑能力不强、配套基础条件薄弱和环境监管基础能力不足三大难题。需要从强化土壤污染修复人才的引进、储备和培养,以科技创新能力提升支撑土壤污染修复产业的发展,拓展投融资渠道、夯实土壤污染修复产业发展的资金保障三方面入手加强土壤污染修复产业的要素支撑能力建设;培育和壮大土壤污染修复产业集群,推进污染土壤污染修复环境管理与工程示范;完善土壤污染修复产业配套基础条件;加强环境监管能力建设,完善土壤环境管理体系,提升项目管理水平。     

Simulation and optimization technologies for petroleum waste management and remediation process control

Leakage and spill of petroleum hydrocarbons from underground storage tanks and pipelines have posed significant threats to groundwater resources across many petroleum-contaminated sites. Remediation of these sites is essential for protecting the soil and groundwater resources and reducing risks to local communities. Although many efforts have been made, effective design and management of various remediation systems are still challenging to practitioners. In recent years, the subsurface simulation model has been combined with techniques of optimization to address important problems of contaminated site management. The combined simulation-optimization system accounts for the complex behavior of the subsurface system and identifies the best management strategy under consideration of the management objectives and constraints. During the past decades, a large number of studies were conducted to simulate contaminant flow and transport in the subsurface and seek cost-effective remediation designs. This paper gives a comprehensive review on recent developments, advancements, challenges, and barriers associated with simulation and optimization techniques in supporting process control of petroleum waste management and site remediation. A number of related methodologies and applications were examined. Perspectives of effective site management were investigated, demonstrating many demanding areas for enhanced research efforts, which include issues of data availability and reliability, concerns in uncertainty, necessity of post-modeling analysis, and usefulness of development of process control techniques.     

土壤环境监测技术规范中的土壤环境质量评价问题

近年来,场地和土壤污染勘查评价与修复逐渐发展成为环境科学和土木工程领域的热点,场地和土壤修复业务随之愈来愈多。但土壤修复理论和技术发展相对缓慢,无法满足土壤修复行业发展的需要。实践中,在场地和土壤污染勘查与评价的现行标准中,对土壤环境质量评价仅考虑了土壤中某物质成分的人为超标问题,而忽视了土壤中自然异常而导致土壤中某物质成分超标问题的评价,且误将土壤中某物质成分的超标等级定为土壤污染程度等级的全部。针对这些问题,本文通过研究,在深入分析各领域土壤污染评价差异的基础上,提出了土壤污染评价的一般过程、方法和标准,供标准修订参考。     

APPLICATION OF ENHANCED ANNEALING TO GROUND WATER REMEDIATION DESIGN1

ABSTRACT: A methodology for ground water remediation design has been developed that interfaces ground water simulation models with an enhanced annealing optimizer. The ground water flow and transport simulators provide the ability to consider site‐specific contamination and geohydrologic conditions directly in the assessment of alternative remediation system designs. The optimizer facilitates analysis of tradeoffs between technical, environmental, regulatory, and financial risks for alternative design and operation scenarios. A ground water management model using an optimization method referred to as “enhanced annealing” (simulated annealing enhanced to include “directional search” and “memory” mechanisms) has been developed and successfully applied to an actual restoration problem. The demonstration site is the contaminated unconfined aquifer referred to as N‐Springs located at Han‐ford, Washington. Results of the demonstration show the potential for improving groundwater restoration system performance while reducing overall system cost.     

Remediation technologies for heavy metal contaminated groundwater

The contamination of groundwater by heavy metal, originating either from natural soil sources or from anthropogenic sources is a matter of utmost concern to the public health. Remediation of contaminated groundwater is of highest priority since billions of people all over the world use it for drinking purpose. In this paper, thirty five approaches for groundwater treatment have been reviewed and classified under three large categories viz chemical, biochemical/biological/biosorption and physico-chemical treatment processes. Comparison tables have been provided at the end of each process for a better understanding of each category. Selection of a suitable technology for contamination remediation at a particular site is one of the most challenging job due to extremely complex soil chemistry and aquifer characteristics and no thumb-rule can be suggested regarding this issue. In the past decade, iron based technologies, microbial remediation, biological sulphate reduction and various adsorbents played versatile and efficient remediation roles. Keeping the sustainability issues and environmental ethics in mind, the technologies encompassing natural chemistry, bioremediation and biosorption are recommended to be adopted in appropriate cases. In many places, two or more techniques can work synergistically for better results. Processes such as chelate extraction and chemical soil washings are advisable only for recovery of valuable metals in highly contaminated industrial sites depending on economical feasibility.     

Integrating Environmental Restoration and Ecological Restoration: Long-Term Stewardship at the Department of Energy

With the ending of the Cold War, several federal agencies are reclaiming land through remediation and restoration and are considering potential future land uses that are compatible with current uses and local needs. Some sites are sufficiently contaminated that it is likely that the responsible federal agency will retain control over the land for the foreseeable future, providing them with a stewardship mission. This is particularly true of some of the larger Department of Energy (DOE) facilities contaminated during the production of nuclear weapons. The use of the term “restoration” is explored in this paper because the word means different things to the public, ecologists, and environmental managers responsible for contaminated sites, such as Superfund sites and the DOE facilities. While environmental restoration usually refers to remediation and removal of hazardous wastes, ecological restoration refers to the broader process of repairing damaged ecosystems and enhancing their productivity and/or biodiversity. The goals of the two types of restoration can be melded by considering environmental restoration as a special case of ecological restoration, one that involves risk reduction from hazardous wastes, and by broadening environmental restoration to include a more extensive problem-formulation phase (both temporal and spatial), which includes the goal of reestablishing a functioning ecosystem after remediation. Further, evaluating options for the desired post remediation result will inform managers and policy-makers concerning the feasibility and efficacy of environmental restoration itself.     

CHALLENGES IN GROUND WATER REMEDIATION: DENSE NONAQUEOUS PHASE LIQUIDS1

ABSTRACT: Dense nonaqueous phase liquid (DNAPL) contaminated ground water has proven to be exceptionally difficult to remediate for both physical and chemical reasons. Since DNAPL's are denser than water, their movement is not governed by the direction of ground water flow as is generally the case for other ground water contaminants. Additionally, DNAPLs' interactions with aquifer solids through processes such as sorption tend to make the pollution linger or sometimes apparently disappear, only to return later. Unfortunately, pump-and-treat systems, the traditional way ground water contamination is addressed, have not been effective in cleaning DNAPL contaminated water. Other remediation technologies continue to be developed to address these problems. Policy changes will also be necessary to effectively address the difficulties associated with ground water remediation.