RANKING HAZARDOUS-WASTE SITES FOR REMEDIAL ACTION

EXECUTIVESUMMARY

OVERVIEW

In 1980, Congress responded to public concern over the Love Canal situation by passing the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). CERCLA initially established the $1.6 billion Superfund program to assess hazardous-waste sites, determine responsible parties, and provide expeditious financing for cleanups when responsible parties did not do so. CERCLA also required the U.S. Environmental Protection Agency (EPA) to develop a National Priority List (NPL) with a minimum of 400 sites for prompt cleanup. This mandate was extended in 1986 by the Superfund Amendments and Reauthorization Act (SARA), which added an-



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action RANKING HAZARDOUS-WASTE SITES FOR REMEDIAL ACTION EXECUTIVESUMMARY OVERVIEW In 1980, Congress responded to public concern over the Love Canal situation by passing the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). CERCLA initially established the $1.6 billion Superfund program to assess hazardous-waste sites, determine responsible parties, and provide expeditious financing for cleanups when responsible parties did not do so. CERCLA also required the U.S. Environmental Protection Agency (EPA) to develop a National Priority List (NPL) with a minimum of 400 sites for prompt cleanup. This mandate was extended in 1986 by the Superfund Amendments and Reauthorization Act (SARA), which added an-

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action other $8.5 billion to finish the job. Implicit in both pieces of legislation was the idea that a few highly contaminated sites could be quickly identified and cleaned up. Experience proved otherwise. Superfund has become a massive program. The number of sites requiring cleanup turned out to be far greater than originally anticipated. In 1977, a year before Love Canal and 3 years before CERCLA, EPA had reported on hazardous contamination at only 421 sites. EPA now expects the NPL to reach 2,000 sites, although other sources have estimated that the eventual total could reach 10,000. Site remediation often has turned out to be far more complex than originally anticipated. For example, although a relatively small fraction of NPL sites is under the jurisdiction of the U.S. Department of Defense (DOD) and Department of Energy (DOE), those sites—where cleanup funding will be provided from the agencies' operating funds, not by Superfund—can be extremely complicated, including hundreds and even thousands of areas contaminated with large quantities and exotic mixtures of hazardous and radioactive contaminants. The dosing of DOD bases and the decommissioning of DOE plants pose a number of additional social, economic, and political issues. Site remediation is also proving to be far more expensive than originally anticipated. The original Superfund of $1.6 billion was designed to dean up 400 NPL sites at an average cost of $3.6 million per site; but by 1990, EPA was projecting a total cost of $27 billion at an average cost of $26 million per site. As new sites are added to the NPL, others have estimated that the total cost of Superfund alone could rise to between $100 billion and $500 billion over the next 30 to 50 years. When the DOD, DOE, state government, and private sector shares are added, the total bill for hazardous-waste site remediation could surpass $1 trillion. This amount competes with expenditures for other pollution-control efforts, as well as other societal needs, such as reducing the national debt, providing health care, improving education, and

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action renewing the nation's public works infrastructure. Given the many pressing national needs, it is doubtful that the United States will be able to fund the huge task of remediating all sites to the cleanest level possible. Thus, the agencies responsible for hazardous-waste site remediation—EPA, DOD, DOE, and others—will be required to make difficult and inevitably controversial choices. It no longer suffices to have a decision-making process or model that only attempts to identify the bad sites. There are too many of them. Faced with this reality, society needs a priority-setting system that helps define a systematic remediation strategy, addressing such questions as where and when available funds should be spent. The sheer cost of the enterprise—to the government, the taxpayer, and the U.S. economy—requires that priorities be set for waste-site remediation to protect human health and the environment. CHARGE TO THE COMMITTEE The National Research Council's Committee on Remedial Action Priorities for Hazardous Waste Sites was formed to assess the principal methods that federal and state agencies are using or developing to rank sites for remediation priority. The committee was asked to consider the intended technical and policy purposes and actual uses of the methods in the ranking decision process; their effectiveness in achieving those purposes; the types and levels of uncertainty of the input data and the methods' resulting limitations; the methods' assumptions; the appropriateness of the assumptions for the methods' intended purposes; the sources, magnitude, and treatment of significant uncertainties in each method; the sensitivity of the resulting score to the method's computation process; and the method's flexibility for follow-up evaluation of site assessments or for comparative analyses of the costs and effec-

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action tiveness of remediation techniques. The committee was asked to identify the information and research needed to establish standards of performance and consistency for nationally applicable hazardous-waste site-ranking methods. The committee examined the hazardous-waste site-ranking and priority-setting models developed or used by EPA, DOD, DOE, and some state governments to help them rank sites for remediation from among the tens of thousands of abandoned hazardous-waste sites. The committee also attempted to understand the larger processes by which these agencies choose sites to remediate and decide the level of remediation for each site. Part of the committee's task was to prepare an interim report evaluating the methods, assumptions, and constraints of the Defense Priority Model (DPM), a ranking method developed by the U.S. Department of Defense. To meet this responsibility, in 1992, the committee completed an interim report entitled: The Department of Defense Priority Model for Hazardous Waste Site Restoration: An Independent Assessment of Methods, Assumptions, and Constraints. (The interim report is discussed in Chapter 5.) DESIRABLE FEATURES OF A PRIORITY-SETTING SYSTEM A priority-setting technique to aid in decision making for hazardous-waste site remediation should be consistent with the purpose intended. It should provide a formal, systematic, and consistent framework to catalog and compare information to help decision makers design strategies, allocate resources, evaluate progress, and inform the public. The factors to be considered include not only potential threats to human health and the environment,

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action but also social and economic factors. A properly designed system should be comprehensive enough to address all of these factors, yet flexible enough to accommodate numerous, often competing objectives. Most important, the method by which information is obtained and used should be objective, explicit, and replicable, so as to preserve the credibility and acceptability of the larger priority-setting process. Ranking models that provide a framework for analyzing information and presenting results are often used as an important step in the process. In this study, the committee found that less information was available about the overall priority-setting processes of the agencies than the ranking models used in that process. For much of the priority-setting processes, concrete procedural descriptions were typically unavailable, so that most of the committee's information had to be sought by exploratory questioning of agency officials and experts who met with the committee. As a result, the committee's findings focus more on site-ranking methods than the broader priority-setting processes. The distinction is an important one. Most of the systems developed to date are used only to rank sites according to some numerical score; these scores are considered, along with other factors, to arrive at actual remedial priorities, which can be quite different from the numerical scores. With this caveat in mind, the committee attempted to compare the tools used or developed by EPA, DOD, and DOE for ranking sites as part of the priority-setting process. The committee evaluated the models based on their adherence to professionally accepted criteria for developing and applying site ranking models, which may be summarized as follows: acceptability and credibility, based on clear statements of the model's purpose and intended users as well as the incorporation of scientific peer review, public participation, and public comment during the model's development;

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action adequacy of the model to account for the risks that contaminated sites pose to human health and the environment, as well as social and economic considerations; appropriateness of the model's logic and mathematical operations; adequacy of the model's documentation to explain and justify why it is designed as it is; thoroughness with which the model has been tested for validity (i.e., its ability to produce a reliable ranking of risks or sites); and appropriateness of uncertainty and sensitivity analyses (i.e., determination of uncertainties in model scores and their implications for site ranking and prioritization). The committee also evaluated the extent to which the models exhibited other desirable features such as "transparency" (i.e., explicitness) and user-friendliness; flexibility in handling different waste sites and updated information; inclusion of cost estimates for remedial options; and security features to prevent unauthorized changes in site data, model parameters, and model outputs. Finally, the committee evaluated the results of a comparative assessment of the three major federal ranking models using a common set of input data from five contaminated waste sites. PRIORITY SETTING AT EPA EPA is involved in remedial decisions at many hazardous-waste sites and must deal with the whole gamut of interested parties and stakeholders. EPA must do all this under continuous public scrutiny and political pressure to remediate sites quickly. Since thorough risk assessments at tens of thousands of sites would be impracticable and unwarranted, EPA needs a mechanism to sort sites quickly on the basis of limited data.

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action The first major step in the Superfund priority-setting process occurs when a nominated site is scored using the Hazard Ranking System (HRS) model. The HRS is a scoring system used to assess the relative threats associated with contaminant releases from different sites. The HRS combines various characteristics of the site, wastes, and surrounding environment to compute an overall score. As part of the calculations, separate scores are computed for each of four exposure pathways: groundwater, surface water, soil, and air. The HRS score, ranging from 0 to 100, is a screening mechanism for determining whether a proposed site is included on the Superfund NPL. Other scoring and ranking systems are used by EPA in later phases of the Superfund process, but such systems are considerably less formal than the HRS. The committee judged the HRS model to be generally well documented and supported. Despite certain technical limitations (see Chapter 4), it is generally consistent with accepted scientific knowledge and has been subjected to extensive peer review, public participation, and public comment. The procedures for determining and combining HRS scores provide relative rankings of sites; it is consequently inappropriate to interpret the resulting HRS score in an absolute sense. Results of the HRS model have been compared to the results of more detailed site assessments based on risk analysis and expert panels. The degree of HRS correlation with these estimates has generally been low to modest. In theory, because the model includes so many factor scores, it is relatively robust with respect to uncertainties in any one of them. In practice, however, the scoring outcome is quite sensitive to the overall effort exerted in data collection at the site, since the score for each environmental pathway is sensitive to the presence or absence of observed contamination in that pathway. Often, the more data, the higher the score. This creates the potential for misinterpretation or even manipulation. The HRS model is broadly applicable to the types of hazardous-waste sites that EPA must evaluate. It emphasizes long-term risks,

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action because EPA addresses immediate threats by other methods before HRS scoring. Because the scores are ordinal (i.e., relative), however, the HRS is inappropriate for selecting or tracking remedial actions. The model does not consider the costs or timing of remediation (issues that are considered at later stages of the priority-setting process), and it does not provide a basis to assess the relative weights given to human health versus ecological impacts. Recent revisions to the original HRS have corrected some deficiencies but have also made the model significantly more difficult to understand and greatly increased the amount of time required to score each site. If EPA remains committed to an early decision about whether to list a site on the NPL, the HRS model, with appropriate modifications as recommended in Chapter 4, may remain the best alternative available. However, modifications to allow for more detailed review of sites with intermediate scores might help to reduce the number of sites which are not added to the NPL but would be if assessed more carefully, and sites that are currently included on the NPL but would not be if assessed more carefully. PRIORITY SETTING AT DOD In the past, DOD (and DOE) were not under great external pressure as they are today to dean up hazardous-waste sites. Many of their sites are in relatively remote or inaccessible areas, and national security considerations inhibited public scrutiny. The source of funds for these cleanups is the agencies' operating funds, not Superfund. As a result, DOD and DOE have had far more control over the choosing of sites for analysis and remediation, and this greater control is reflected in their priority-setting models.

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action DOD's site-remediation goals are to remove imminent health threats, address the worst sites first, meet CERCLA and SARA requirements at NPL sites, and use resources effectively and efficiently. Unlike EPA, which uses the HRS model only for initial screening and NPL listing, DOD developed the Defense Priority Model (DPM) to assist in ranking sites for remedial action. Because DOD usually was under less pressure than EPA to make a quick yes-no decision at each site, it was able to obtain more field data for use in its model. The resulting numerical score, from 0 to 100, was intended to represent the relative potential threat that a contaminated site poses to human health and the environment. DPM uses a combination of quantitative data and qualitative approximations. It calculates separate subscores for adverse effects on humans and ecological resources via surface water, groundwater, air, and soil pathways, and then combines them into an overall site score. The committee considers that to be a reasonable approach, but some of the assumptions, algorithms, and methods embedded in the model have a weak theoretical basis. DPM also does not explicitly address social and economic impacts, nor is it clear that DOD substantially addresses these factors through a separate evaluation process. The DPM is user-friendly and its structure is clear, but it contains portions that have not been validated, and there has been no attempt to validate the overall model. Further, the DPM's linear scale produces a very tight range of site scores relative to the limits of 0 to 100; in 1991, 65 percent of the 284 sites evaluated with DPM had scores between 13 and 37. This narrow interval may limit DPM's ability to discriminate between sites. A simple sensitivity analysis of the 50 sites with the highest DPM scores demonstrated that uncertainties in model inputs and structure can have large effects on the scores and ranking of sites. Spreading out the numerical scores with alternate algorithms might allow better discrimination among sites. Because DPM was still undergoing development during the committee's evaluation, it has the potential

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action for this kind of revision and improvement. (After completing its analyses, the committee was informally told that DOD has decided not to use the DPM for site ranking.) PRIORITY SETTING AT DOE DOE faces two additional challenges in cleaning up its hazardous waste sites. The first is the greater complexity of the problems at sites that often contain radioactive materials, toxic chemical wastes, and mixed (radioactive-chemical) wastes. The second is that more than 60 percent of DOE's cleanup funds are committed by formal agreements with EPA regions and the states, mandating that certain sites be remediated by specific dates. Consequently, DOE must optimize the allocation of scarce resources subject to a series of constraints, notably these legal agreements. To manage its complicated remedial effort, DOE has developed an Environmental Restoration Priority System (ERPS), the goals of which are to document and support DOE's budget requests and to allocate funds among its programs and installations. The system is more comprehensive than HRS or DPM, explicitly addressing social and economic impacts, cost considerations, and uncertainties. However, it does not use a "worst-first" approach, and the results would not necessarily lead to the remediation of sites according to the magnitude of the risks they pose to public health and the environment. ERPS builds more of the decision-making process into the model itself, rather than relying on an external process that may not be as amenable to outside scrutiny. ERPS is less than 5 years old, has not been applied much in the past, and is not expected to be used by DOE in the near future, so the committee was unable to evaluate it as thoroughly as it did the EPA and DOD models. ERPS is based on a sophisticated implementation of multi-

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action attribute utility theory, a decision-making approach that allows for the simultaneous evaluation of multiple objectives and factors—in this case, not only health risks but also environmental, social, economic, and political impacts. Implementation involves four steps: Structure the decision problem by specifying the objectives, identifying the alternatives, and determining attributes or outcome measures by which results can be assessed. Assess the possible impacts of different alternatives, using probability distributions if exact effects cannot be determined. Determine the preferences (values) to the decision maker by assigning different weights to the various attributes or effects of each alternative. Evaluate and compare alternatives. DOE's computer model known as MEPAS (Multimedia Environmental Pollutant Assessment System) is used to generate summary risk indicators for use in ERPS. MEPAS focuses only on adverse health impacts, not on environmental or other effects; but it includes radioactive, chemical, and mixed wastes, multiple pathways, and both direct and indirect exposures. The ERPS procedure for addressing health risks suffers from a lack of data as a basis for most of the estimates involved. The part of ERPS that combines individual risks with population risks appears to overemphasize large populations exposed to low risks, at the expense of small populations exposed to extremely high risks. A more sophisticated approach to address risk variability is needed. One of the most innovative aspects of ERPS is "uncertainty reduction" as an objective in ranking budget cases. In the early stages of environmental restoration, a great deal of uncertainty may exist at an installation regarding the actual levels and types of wastes, the risks they pose to health and the environment, and the costs of mitigating these problems. In ERPS, formal approaches

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action using decision-analysis techniques are directed toward determining, in explicit economic terms, the value of activities that will eliminate these uncertainties. PRIORITY SETTING BY STATE GOVERNMENTS State governments have important responsibilities for hazardous-waste site remediation. Sites placed on the NPL will be cleaned up with federal money only if the state agrees to pay 10 percent of the capital cost and all future operating and maintenance costs. Many states also have "state Superfund" programs for dealing with sites even if they are not placed on the federal NPL. Some states have made an investment in hazardous-waste site remediation that, on a per capita basis, rivals those of the federal agencies. The Environmental Law Institute (ELI) reported that, as of 1991, 29 states were operating remediation programs supported by enforcement authorities and dedicated funds; another 12 states had legal authority to conduct cleanups but lacked funding and staffing. Several states have multiple statutes that provide authority for various remediation activities at sites that are not covered by Superfund. ELI found that 24 states had their own priority-setting systems. These states do the HRS scoring for EPA and typically choose as state Superfund sites all of those not forwarded to EPA for listing on the NPL. The committee observed many different scoring approaches among the states, although they generally used the same types of input data. The state approaches examined by the committee fall into three categories: (1) HRS-like models (e.g., California, Ohio, Oregon, and Washington); (2) other explicit numeric systems leading to a site-specific score (e.g., Michigan); and (3) characterization of sites into three or more groups based on narrative description of the

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action severity of effects (e.g., Missouri, Montana, and New York). The third approach evaluates up to seven characteristics but involves no mathematical combination of factors to yield a score. Any one of a number of potential effects could lead to a maximum score, and the analyst is given considerable flexibility in deciding which potential effects to pursue in more detail. In many cases, there is evidence of very thoughtful development of site ranking models by state agencies. However, the relationships between the model parameters and the strategies for combining the parameter values are often unclear and undocumented. COMPARATIVE ASSESSMENT OF FEDERAL PRIORITY-SETTING MODELS The committee undertook an assessment of the three federal ranking models—HRS (EPA), DPM (DOD), and MEPAS (DOE)—to compare the outcomes they would yield from a common set of input data developed from a common set of five actual waste sites. The committee took into consideration that the agencies developed their models for different purposes and for use at different stages of their respective decision-making processes. Despite these differences, however, the three models should be expected to produce generally similar relative rankings of the same set of hazardous-waste sites—that is, they should generally give the same indication of which sites are "worse" (i.e., produce higher risks) compared with other sites. DOE's ERPS model was not included in the scoring exercise because its design and application are so different from the HRS, DPM, and MEPAS models. Differences among these models make exact comparisons difficult. For example, DPM and HRS are scoring systems that assign points to a site based on important site characteristics, but without directly modeling the process of contaminant transport.

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action MEPAS, on the other hand, includes algorithms for contaminant migration and fate and the resulting risks to human health. The committee provided each agency with a common set of site descriptions, narratives, background, and data for 5 sites. Each agency was asked to run its own ranking model and to provide the committee with the resulting scores. To ensure comparable applications, the three agencies communicated extensively during the exercise. After completing the model runs, each agency summarized its results, scaled its scores between 0 and 100, and submitted reports to the committee. In general, the scores from the three models tended to follow similar trends from site to site, but in each model, the reasons for higher scores were often very different. Even when the models produced generally consistent site scores, they tended to differ as to which were the dominant risk-producing contaminants and transport pathways. The three models did not all agree on which of the five sites posed the highest potential risk. The dominant factor leading to differences in site scores among the models appeared to be differences in the selection and weighting of site data, particularly for contaminants and environmental pathways, and not differences in model structure. OVERALL CONCLUSIONS AND RECOMMENDATIONS Current Ranking Models The committee believes that formal mathematical ranking models play less of a role than they can and should in determining remedial priorities for hazardous-waste sites. However, all of the current ranking models were found to fall short on several important aspects of model development, including documentation, validation, completeness, transparency, and inclusion of social and

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action economic factors. There is a large base of scientific knowledge on which to build such a system, and there are no large gaps that would first require further research, but the agencies currently use this science base differently. The mixture of science and policy components in the current models, while not inappropriate, complicates analysis and comparisons among priority-setting processes. The committee recommends that the agencies work in close collaboration to improve their model development programs in at least four general ways: clearer documentation of core elements of the model for technical and lay audiences; greater public involvement in the process of developing a model and applying it to a given site; better validation of model components, reference data, and parameter values to reflect current and new knowledge; and more explicit consideration of social and economic factors, particularly the costs of remediation alternatives. Current Priority-Setting Processes The site-ranking models are only one part of the overall priority-setting process for hazardous-waste site remediation. By comparison, the agencies' current priority-setting processes themselves are not well defined, and appear to lack adequate evaluation, consistency, and effective oversight. None of the agencies defines its overall priority-setting process in a manner that is explicit, clear, well documented, and open to scientific and public scrutiny. Approaches to priority setting are not always consistent even within a given agency, and there is no consolidated priority setting process for sites at the national level.

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action Toward a Unified National Approach The enormous costs of environmental remediation certainly justify the development of an objective, replicable, and equitable priority-setting process that is fully open to public scrutiny. At the present time, there is no consistent relationship between the hazard present at a site and the process by which the different agencies screen and evaluate a site for remediation. For example, EPA works closely with DOE and the states to develop remediation plans for some DOE sites, but other sites are the responsibility of a single agency, and each agency has developed its own unique protocols. As a result, it is extremely difficult to compare the degrees of cleanup and levels of protection being provided or even pursued by the different agencies. The process of evaluating and cleaning up sites no longer follows the simple model that the creators of Superfund envisioned. During a period of pressure to accomplish more with fewer resources, the use of several independent and inconsistent methods may be neither effective nor prudent. The committee therefore recommends that the government consider the development of a unified national process of scientific hazardous-waste site analysis to replace the current multiple approaches. Specifically, the committee recommends a new system designed to achieve three main goals: Greater consultation and collaboration among the agencies. This goal is the least intrusive to existing agency approaches. EPA, DOD, and DOE should form an interagency task force to coordinate the use of site-ranking models and determine how they can share data, expertise, quality control, validation procedures, and other information. The agencies would also share their respective approaches for including social and economic factors and for communicating with interested parties. Scientific consistency. This would require that each site be

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action subjected to the same scientific protocols for evaluating health and safety, environmental impact, and economic costs and benefits. A unified approach could result in more explicit, thorough, and credible scientific input into the political process of deciding on resource allocation for site identification, ranking, and remediation. Decision-making consistency. This would add procedural and geographical consistency to scientific consistency. That is, all agencies would apply the same decision-making protocols to every site. Priority-setting decisions would not be influenced by which agency was responsible for the site—solvent spills at a factory in Illinois would be treated the same way as solvent spills at a DOD base in Arizona or a DOE facility in Ohio. Priority could even be assigned by a central interagency group, not exclusively by the parties currently charged with remediating the site. Decision-making consistency could require some reorganization of authority among federal agencies and would probably include some shifting of funds among agencies. The committee recommends a three-tiered approach. This approach draws heavily on procedures already being used by federal agencies, either explicitly or implicitly, and thus requires no radical changes in thinking or development. Mathematical models would be used in all three tiers to assist in ranking sites. However, some factors are not readily quantifiable and thus would need to be addressed outside of the models. The first tier involves screening candidate hazardous-waste sites. The site is evaluated to determine whether to (1) move it to the second tier for detailed characterization, (2) eliminate it from further consideration, or (3) gather more data before making a decision. These decisions would be based on limited information about potential risks to human health and the environment. EPA's HRS model and DOD's Defense Priority Model were developed, in part, with such a purpose in mind. The second tier involves detailed site investigation to assess the

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action extent of contamination at each site, the various environmental media and populations that may be affected, and the costs of remedial actions. The data gathered here should be sufficient to conduct formalized assessments of relative risks to human health and the environment, including the rates at which contaminants spread in time and space. In addition, at least preliminary estimates should be made of the economic damages to the resources. The overall objective in the second tier is a relative ranking of sites and a cost evaluation for at least three alternate levels of remediation: remediation that is sufficient to contain hazardous contaminants so they no longer present a significant risk to human health or the environment (a no-action alternative might be appropriate for this level at some sites, but at other sites land-use controls and restricted access might be required); remediation that is sufficient to restore the site to the point where no land-use restrictions are necessary, and more extensive cleanup (comparable to returning the site to precontamination quality). The third tier would combine the ranking by risks and the estimated costs of remediation alternatives to determine what sites to address first and what levels of control to pursue. This process would still involve some mathematical formalization, but it would also include broader social and economic considerations that would be addressed outside of a mathematical model. This process needs to be more explicit than current practices so that funds can be allocated in a more open and cost-effective manner. The committee does not recommend a particular framework for doing this, but clearly one is needed. A unified national approach would have the advantage of being compatible with current agency practices. It could make use of knowledge gained from the application of current models. Be-

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action cause the agencies would all use the same procedures in Tiers 1 and 2, they would be able to devote greater effort in collaboration to examine the scientific basis for the mathematical algorithms, evaluate the validity of the models with respect to their intended use, and determine the sensitivity of the models to data inputs. The agencies could also share the costs of developing documentation and acquiring appropriate data inputs. The resulting consistency could increase the overall credibility of the process. A single consistent national process that explicitly includes calculation of economic costs and benefits of remediation would be advantageous to decision-makers because it would make more explicit the reality that costs and benefits are always factored in some way into decisions. Such an explicit method would increase the credibility of the process by providing estimates that could be compared with actual site costs and benefits—in a sense, a kind of costs-and-benefits accounting. Also, a dearly documented costs-and-benefits protocol greatly decreases the chances of inadvertent or intended skewing of cost and benefit estimates for reasons that have nothing to do with hazard or remediation outcomes. The three levels of remediation costs considered in Tier 2 would allow better judgments to be made concerning the degree of remediation to pursue at a given site. The relative costs for different levels of remediation would be provided more explicitly, in a manner understandable by decision makers and the public. For example, if the estimated cost of remediation at a given site (Site One) is $2 million for the first level and $3 million for the second, while the costs at a second site (Site Two) are $2 million and $100 million, respectively, and if both sites pose roughly equivalent risks, it should generally be convincing that the best use of limited remediation funds would likely be to dean Site One to the second level and Site Two to the first level. The benefits of cleanup would also be calculated. The decision for the two sites in the example might change if the benefits of the second level remediation of Site Two were $400 million compared to $100 million in costs.

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action When funding shortfalls occur, a single consistent process could facilitate negotiations among federal agencies, state and local governments, tribal governments and Native American organizations, private organizations, citizens groups, and other interested parties because they would all be negotiating from the same data base and on a more level playing field. Ideally, such a uniform approach would help the federal agencies develop a joint strategic plan for remediation under a variety of resource-constrained scenarios. Another advantage of a single uniform scientific approach is that every analysis would treat every person the same and every forest consistently, regardless of whether they are located in an urban area of New Jersey or Louisiana, or a rural area of Maine or Arizona. The decision-making would allocate remediation resources on the basis of costs, benefits, and need for remediation rather than on the basis of the ability of a responsible party, state, business, or federal agency to pay. The committee believes that a unified approach to setting priorities would better accommodate changes in the scientific, technological, economic, and political processes in the United States and abroad than do the existing multi-organizational approaches. This approach would provide a more rational basis for decisions about priority setting and levels of remediation at hazardous-waste sites. Vast resources will be allocated for hazardous-waste site remediation throughout the 1990s and beyond. If the United States is ever to adopt a uniform national scientific and decision-making process, it makes sense to do it soon.

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action RANKING HAZARDOUS-WASTE SITES FOR REMEDIAL ACTION

OCR for page 1
Ranking Hazardous-Waste Sites for Remedial Action This page in the original is blank.