Waste management project's alternatives: A risk-based multi-criteria assessment (RBMCA) approach

This paper examines the evaluation of a waste management project’s alternatives through a quantitative risk analysis. Cost benefit analysis is a widely used method, in which the investments are mainly assessed through the calculation of their evaluation indicators, namely benefit/cost (B/C) ratios, as well as the quantification of their financial, technical, environmental and social risks. Herein, a novel approach in the form of risk-based multi-criteria assessment (RBMCA) is introduced, which can be used by decision makers, in order to select the optimum alternative of a waste management project. Specifically, decision makers use multiple criteria, which are based on the cumulative probability distribution functions of the alternatives’ B/C ratios. The RBMCA system is used for the evaluation of a waste incineration project’s alternatives, where the correlation between the criteria weight values and the decision makers’ risk preferences is analyzed and useful conclusions are discussed.     

The active role of state laws in superfund cleanups

The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) did not ignore the fifty individual states when establishing responsibility, authority, and liability for cleaning up hazardous waste sites. Although CERCLA gives EPA the ultimate authority to select a remedy for a contaminated site, the law was drafted not only to allow for state activity without EPA, but also for significant state input when EPA is involved. The relationship between a state (and its environmental laws) and EPA can help decide the remedial and financial interests of any potentially responsible party (PRP). This article discusses the relevant CERCLA provisions, recent court decisions, and resolved and unresolved issues in federal-state Superfund involvement, and recommends several common-sense strategies for PRPs when working with a state in a Superfund cleanup.     

Successful UV/oxidation of VOC-contaminated groundwater

Ultraviolet light/oxidation has proven its effectiveness in destroying volatile organic chemicals (VOCs) found in groundwater during a U.S. Environmental Protection Agency (EPA) field study. Under the Superfund Innovative Technology Evaluation (SITE) program, PRC Environmental Management, Inc., and EPA monitored the performance of a system employing advanced oxidation techniques at the Lorentz Barrel & Drum (LB&D) Superfund site in San Jose, California. The firm of Ultrox International (Santa Ana, CA) demonstrated its technology for combining ultraviolet light, hydrogen peroxide and ozone to oxidize toxic organic chemicals found in water. All evaluation criteria were successfully met in the study's results. Greater than 90% of the VOCs were removed. The applicable discharge standards (National Pollution Discharge Elimination System) were attained, and there were no emissions.     

On-site analytical support: A cost-effective alternative to fixed laboratory services

Two recent projects involving soils remediation at Superfund sites in southern New Jersey and northeastern Pennsylvania exemplify the power of “real time” field analytical support in reducing time and expense during a project's remedial phase. The remediation efforts at both of these CERCLA sites were supported by ERM-FAST on-site analytical facilities which, in a “real-time” scenario, achieved all data quality objectives (DQOs), met all regulatory agency requirements, and satisfied the client's needs. Both of these sites offer illustrations of the effectiveness of field analysis for vastly differing site contaminants. The client benefited from substantial savings on analytical cost as well as the savings realized through efficient and effective process and schedule management.     

A risk-based approach to how clean is clean

Clearly defined remedial action objectives are a key factor in successful remediation programs. Chemical-specific cleanup criteria are critical components of remedial action objectives. A common risk-based approach can be applied for developing cleanup criteria for remediations under CERCLA, RCRA, and TSCA. This approach involves four steps: identify regulatory requirements; identify chemical-specific cleanup guidelines from previous cleanups; evaluate site-specific risk considering mitigating factors for a given site; select the final cleanup criteria based on information from the first three steps. To describe this approach, this paper presents a case study on a PCB cleanup conducted under TSCA. An objective risk-based approach was used to capitalize on the flexibility built into EPA's PCB cleanup guidelines. EPA granted an exemption to the stated policy on the basis of competing risk factors using a comparative risk-assessment approach. Similarly, risk assessment can be used to take advantage of regulatory flexibility in the selection of applicable or appropriate and relevant requirements (ARARs) under CERCLA, or in the selection of media protection standards under RCRA.     

Screening Technology Trains for DNAPL Remediation

The Department of Energy (DOE) is conducting a Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) mandated Remedial Investigation/Feasibility Study for a site contaminated with Dense Non-Aqueous Phase Liquid (DNAPL) pollutants. Three key efforts were a hydrogeological modeling approach, the generation of feasible sequences of technologies, and the screening of alternative technologies. This research uses a decision analysis process to provide a quantitative assessment of the candidate technologies. Decision analysis modeling was used to gain insight into each sequence of technologies. Sensitivity analysis was also conducted to assess the impact of key assumptions. The results provided the DOE with an objective and traceable rationale for screening and reducing all of the potential technology combinations to 58 technology combinations and a method for identifying the top scoring combinations. The approach has wide applicability to similar CERCLA remediation efforts.     

Application of interval 2-tuple linguistic MULTIMOORA method for health-care waste treatment technology evaluation and selection

The management of health-care waste (HCW) is a major challenge for municipalities, particularly in the cities of developing countries. Selection of the best treatment technology for HCW can be viewed as a complicated multi-criteria decision making (MCDM) problem which requires consideration of a number of alternatives and conflicting evaluation criteria. Additionally, decision makers often use different linguistic term sets to express their assessments because of their different backgrounds and preferences, some of which may be imprecise, uncertain and incomplete. In response, this paper proposes a modified MULTIMOORA method based on interval 2-tuple linguistic variables (named ITL-MULTIMOORA) for evaluating and selecting HCW treatment technologies. In particular, both subjective and objective importance coefficients of criteria are taken into consideration in the developed approach in order to conduct a more effective analysis. Finally, an empirical case study in Shanghai, the most crowded metropolis of China, is presented to demonstrate the proposed method, and results show that the proposed ITL-MULTIMOORA can solve the HCW treatment technology selection problem effectively under uncertain and incomplete information environment.     

Alternatives to incineration in remediation of soil and sediments assessed

Contamination of soil and sediment by pollutants represents a major environmental challenge. Remediation of soil during the original Superfund years consisted primarily of dig and haul, capping, or containment. The 1986 amendments to CERCLA—SARA—provided the incentive for treatment and permanent remedies during site remediation. Thermal treatment, which routinely achieves the low cleanup criteria required by RCRA land-ban regulations, became one of the major technologies used for cleanup under the concept of ARAR. As the remediation industry matured and recognized specific market niches in soil remediation, a number of new technologies emerged. Thermal desorption, bioremediation, soil vapor extraction, soil washing, and soil extraction are being used on sites at which the technology offers advantages over incineration. In addition, a continuing stream of emerging technologies is being presented that requires careful evaluation relative to existing cleanup methods. Each of these technologies offers a range of options for achieving appropriate cleanup criteria, application to different soil matrices, cost, time of remediation, and public acceptability. Balancing cleanup criteria defined by regulation or risk assessment with technology cost and capability affords the opportunity to solve these problems with appropriate balance of cost and protection of human health and the environment.     

Application of In-Situ Vitrification at the Parsons Chemical Site

This article presents the results of demonstration of Geosafe Corporation's in-situ vitrification (ISV) technology at the Parsons Chemical/ETM Enterprises Superfund site in Grand Ledge, Michigan. The primary focus of this article is on the EPA's Superfund Innovative Technology Evaluation (SITE) Program assessment of the sixth melt. A total of eight melts were performed during this project. This demonstration was part of the SITE Program Demonstration (USEPA, 1994), which helped develop innovative hazardous waste treatment technologies, especially those offering permanent remedies for contaminated Superfund and other hazardous waste sites. The demonstration results are not only applicable to this particular project, but are also indicative of other Geosafe project experiences and demonstrate the current state of the ISV technology. The demonstration included two phases. In the first phase, the ISV technology was used to treat the Parsons contaminated soil. In the second phase, post-testing and analysis were conducted about one year after the ISV technology was applied to confirm that the vitrification was completed and that no contamination migration had occurred.     

Effects of cosolvency in the fate and transport of PCBs in soil

Under the purview of EPA's Remedial Engineering Management (REM III) Superfund contract, a CERCLA RI/FS was performed at the Pinettes Salvage Yard site located in Washburn, Maine (EPA Region I). The purpose of the RI/FS was to fully characterize the nature, extent, and fate and transport of PCB contamination resulting from an alleged surface spill of transformer dielectric fluid containing Arochlor 1260 (a polychlorinated biphenyl) and various volatile and semivolatile organic constituents. The RI/FS was performed subsequent to both an immediate removal action (IRA) and a deletion remedial investigation (DRI) performed by EPA contractors. Results of both efforts indicated that the site was unsuitable for deletion from the National Priorities List (NPL) because the site soils contained elevated levels of PCBs. This article presents a case history of the extensive field investigations performed to characterize the contaminant source and evaluate the fate and transport of PCBs in site soils. These investigations included on-site mobile laboratory gas chromatograph (GC) analytical techniques for PCBs and targeted volatile and semivolatile organic compounds; confirmatory Contact Laboratory Program (CLP) laboratory analyses of soils, sediments, surface water, and groundwater samples; statistical analyses and correlation of field mobile laboratory GC data with CLP laboratory analytical results; and an evaluation of the potential effects of cosolvency in the fate and transport of PCBs in subsurface soils.     

Thermal treatment and non-thermal technologies for remediation of manufactured gas plant sites

More than 1500 manufactured gas plant (MGP) sites exist throughout the U.S. Many are contaminated with coal tar from coal-fueled gas works which produced ‘town gas’ from the mid-1800s through the 1950s.^1,2 Virtually all old U.S. cities have such sites. Most are in downtown areas as they were installed for central distribution of manufactured gas. While a few sites are CERCLA/Superfund, most are not. However, the contaminants and methods used for remediation are similar to those used for Superfund clean-ups of coal tar contamination from wood-treating and coke oven facilities. Clean-up of sites is triggered by regulatory pressure, property transfers and re-development as well as releases to the environment — in particular, via groundwater migration. Due to utility de-regulation, site clean-ups may also be triggered by sale of a utility or of a specific utility site to other utilities. Utilities have used two approaches in dealing with their MGP sites. The first is ‘do nothing and hope for the best’. History suggests that, sooner or later, these sites become a bigger problem via a release, citizen lawsuit or regulatory/public service commission intervention. The second, far better approach is to define the problem now and make plans for waste treatment or immobilization. This paper describes recent experience with a high capacity/low cost thermal desorption process for this waste and reviews non-thermal technology, such as bio-treatment, capping, recycling, and dig and haul. Cost data is provided for all technologies, and a case study for thermal treatment is also presented.     

How chemically stable is stabilized hazardous waste?

Bioassays can provide meaningful information about the relative toxicity of remediated soil samples, revealing the unwelcome toxic side effects produced by some cleanup projects. Section 121 of CERCLA's 1986 amendments calls for hazardous waste site remediations to permanently and significantly reduce the volume, toxicity, and mobility of hazardous substances, pollutants, and contaminants. Traditional engineering technology has focused on reducing volume and mobility, assuming that such reduction would lead to reductions in toxicity. Environmental scientists have argued, however, that such reductions are not always the result, but lack of consensus on how hazardous waste mixtures should be measured toxicologically has slowed development of integrated assessments. The aquatic and terrestrial bioassays discussed in this article are evaluated for various chemicals, mixtures of chemicals, and actual waste site chemical mixtures at a Superfund mobility reduction project in Kent, Washington. Results suggest that although remediation accomplished the primary objective of reducing mobility, it also introduced toxic effects. These tradeoffs must be viewed holistically when the ultimate performance of cleanup measures is judged.     

Chromium removal from groundwater using simple physical/chemical treatment

Groundwater at a Superfund site in west Texas has been found to contain chromium at concentrations exceeding EPA's drinking water standard of .05 mg/l. Alternative treatment methods for this site were investigated; this article presents the evaluation of a physicochemical treatment system, in which removal of total chromium to levels below the drinking water standard was achieved through reduction of hexavalent chromium and subsequent removal by coprecipitation with iron. Costs for the construction of the pilot and full-scale systems are also discussed.     

Superfund: Past experiences and new directions

Ten case studies of Superfund sites were done by the University of Tennessee's Waste Management Research and Education Institute. The case studies, which focused on stakeholder perspectives of site processes, revealed a number of problems with the Superfund process. They also revealed that some improvements had begun to take place. Recently, several modifications have been instituted in the Superfund program. Although it is too early to determine their efficacy, it appears that the Superfund program is beaded in the right direction.     

Evaluation of remedial countermeasures using the analytic network process

The aim of this paper is to present an evaluation method to aid decision makers in the prioritization and selection of appropriate countermeasures at the planning stage of site remediation. We introduced a hierarchical network (hiernet) decision structure and applied the Analytic Network Process (ANP) supermatrix approach to measure the relative desirability of the remedial alternatives using the decision maker's value judgment as input. A simplified illustrative example is presented to elucidate the process, as it is being applied to evaluate the feasible remedial countermeasures of a contaminated site caused by uncontrolled landfill. Four decision models derived from the generalized hiernet were examined to describe the effect of hierarchic functional dependence, inner dependence and feedback cycle on the derivation of the priority weights. The ANP could provide a more flexible analytical framework to break down one's judgment through a more elaborate structure in a systematic way to understand the complexity of the decision problem. The proposed method therefore may not only aid in selecting the best alternative but also may help to facilitate communication to understand why an alternative is preferred over the other alternatives through the analysis of the derived weights and its underlying decision structure.     

SITE Program Success: Cost Savings to Government and Increased Revenue for Technology Vendors

The Superfund Innovative Technology Evaluation (SITE) program is a program mandated by Congress through the 1986 Superfund Amendments and Reauthorization Act (SARA). The original Superfund allowed no provisions for research and development of needed remediation technologies. Problems arose when the demand for involved, complex treatment could not be met by the traditional contain, haul, and dispose process that hazardous waste handlers had become familiar with. In response to the increasing complexity of hazardous waste site remediation, SARA called for an “Alternative or Innovative Treatment Technology Research and Demonstration Program.” As a result, EPA's Office of Solid Waste and Emergency Response and the Office of Research and Development established the SITE program. This article is a historical analysis of the unique cost savings of the SITE program.     

Assessment of health-care waste disposal methods using a VIKOR-based fuzzy multi-criteria decision making method

Nowadays selection of the appropriate treatment method in health-care waste (HCW) management has become a challenge task for the municipal authorities especially in developing countries. Assessment of HCW disposal alternatives can be regarded as a complicated multi-criteria decision making (MCDM) problem which requires consideration of multiple alternative solutions and conflicting tangible and intangible criteria. The objective of this paper is to present a new MCDM technique based on fuzzy set theory and VIKOR method for evaluating HCW disposal methods. Linguistic variables are used by decision makers to assess the ratings and weights for the established criteria. The ordered weighted averaging (OWA) operator is utilized to aggregate individual opinions of decision makers into a group assessment. The computational procedure of the proposed framework is illustrated through a case study in Shanghai, one of the largest cities of China. The HCW treatment alternatives considered in this study include “incineration”, “steam sterilization”, “microwave” and “landfill”. The results obtained using the proposed approach are analyzed in a comparative way.     

Two decision analysis approaches: Choosing a chemical analysis method

This article illustrates how two different decision analysis (DA) methods can be used to assist in making environmental remediation decisions. The two DA methods are Multiattribute Utility Theory (MAUT) and the Analytic Hierarchy Process (AHP). MAUT and AHP differ greatly in their underlying philosophies. MAUT employs an interval scale and constructs utility functions that quantify the total utility to the decision maker of each technology alternative; AHP employs a ratio scale and uses pairwise comparisons to produce a final ranking of the alternatives that reflects the decision maker's comparative preferences. In this study, the same technology was ranked first by both methods; however, the remaining rankings did not agree. Also, statistical analysis indicated that some score differences may be statistically insignificant. These results are presented and discussed along with a comparison of the features, advantages, and disadvantages of these two DA approaches.     

Suitability analysis for siting MSW landfills and its multicriteria spatial decision support system: Method,implementation and case study

Multicriteria spatial decision support systems (MC-SDSS) have emerged as an integration of geographical information systems (GIS) and multiple criteria decision analysis (MCDA) methods for incorporating conflicting objectives and decision makers’ (DMs’) preferences into spatial decision models. This article presents a raster-based MC-SDSS that combines the analytic hierarchy process (AHP) and compromise programming methods, such as TOPSIS (technique for order preference by similarity to the ideal solution) and Ideal Point Methods. To the best of our knowledge it is the first time that a synergy of AHP and compromise programming methods is implemented in raster-driven GIS-based landfill suitability analysis. This procedure is supported by a spatial decision support system (SDSS) that was developed within a widely used commercial GIS software package. A real case study in the Thrace region in northeast Greece serves as a guide on how to conduct a suitability analysis for a MSW landfill site with the proposed MC-SDSS. Moreover, the procedure for identifying MSW disposal sites is accomplished by performing four computational models for synthesizing the DMs per criterion preferential system. Based on the case study results, a comparison analysis is performed according to suitability index estimations. According to them Euclidean distance metric and TOPSIS present strong similarities. When compared with Euclidean distance metric, TOPSIS seems to generate results closer to that derived by Manhattan distance metric. The comparison of Chebychev distance metric with all the other approaches revealed the greatest deviations.     

Rethinking groundwater monitoring at the Hanford Site

Groundwater monitoring at Department of Energy's (DOE's) Hanford Site is a large, expensive undertaking serving multiple purposes, including compliance with regulations and DOE orders, remediation efforts under CERCLA, and sitewide risk evaluations. Like most large Federal facilities, the monitoring program currently in place has evolved and grown overtime as new requirements were established and groups were assigned to address them. DOE and its regulators simultaneously awakened to the fact that there was a need to reevaluate the monitoring activities at Hanford, to better integrate the program, to avoid duplicative sampling, to improve everyone's understanding of the performance of the network, and to evaluate whether adequate data could be collected for lower cost. This paper describes the approch that was developed to guide the rethinking effort with direct and extensive involvement of DOE, EPA, Washington Department of Ecology, Indian Tribes, and DOE Contractors, and how this approach was applied to a large portion of the site. Both the human element of the process (cultural change), as well as some of the technical details associated with the effort, including a flexible application of EPA's data quality objectives process, are discussed.