As noted in Chapter 2, numerous contextual factors can affect the nature and extent of the measures taken to accomplish long-term institutional management. In particular, seven factors often constrain the range of decisions and actions realistically available:
scientific and technical capability;
laws and regulations;
values of interested and affected parties; and
The measures of institutional management—contaminant reduction, contaminant isolation, and stewardship—were described in Chapter 3, Chapter 4, and Chapter 5, respectively. At any stage in the long-term disposition of a waste site, the above factors will affect how each of the three sets of measures (or “legs of the stool”) is implemented, and also what the balance among the measures will be. These seven contextual factors thus can be thought of as the rungs of the committee's conceptual stool. For individual sites, given their variability, different emphasis may be placed on each of these contextual factors, depending on the contaminants present, current and projected future land use for the site and adjacent areas, and local and national economic, social, legal, and political considerations. These seven contextual factors and their characteristics and potential effects on site disposition decisions are considered below.
The primary objective in the disposition of most sites is to reduce the level of risk1 to acceptable levels. Often, human health risks are of greatest concern. These risks can be categorized using dimensions such as the age of
Risk is defined as the probability that something (a hazard) will cause harm or injury, combined with the potential severity of that harm or injury.
those at risk (e.g., adults, children), their relationship to the site (e.g., site workers, members of the public), the possible diffusion of the risk (e.g., local, global), and the nature of the possible effects (e.g., mortality, morbidity). Increasing consideration also is being given to ecological risk (i.e., the possibility of adverse impacts from contaminants on living organisms other than humans). While radiological protection standards for human health are thought to be protective of other living organisms in most cases (United Nations Scientific Committee on the Effects of Atomic Radiation, 1996; National Council on Radiation Protection and Measurement, 1991; International Atomic Energy Agency, 1976, 1979), some non-human species are particularly sensitive to certain chemical contaminants (e.g., copper and zinc concentrations acceptable in drinking water for humans are toxic to trout). In addition, disruptions to these organisms and their habitats from remediation activity or from prospective site reuse is also of concern.
Of the seven contextual factors listed above, risk is arguably the most important in site disposition as it, or perceived risk, may drive both the need for remediation and the level of stewardship required. The greater the risk, the greater should be the efforts required to reduce contaminants, isolate them, and carry out stewardship activities on sites containing residual contaminants. Further, the extent to which risk can be reduced often defines the extent of reliance on the respective “legs of the stool.” Factored into this equation, however, some contaminant reduction and isolation measures also create human risks (e.g., by exposing remediation workers or by disturbing contaminants and making them mobile), or, as noted above, ecological risks. For example, contaminated sediments may be left in place in White Oak Creek at the Oak Ridge Reservation, in part to avoid disruption of the creek 's ecology by dredging. Similarly, at the Nevada Test Site managers noted concerns that the surface soil cleanup could disrupt the site 's sensitive desert ecology.
Risk and Performance Assessment
Risk is often estimated through risk assessment, essentially an attempt to estimate the hazards of contaminants to the environment and to various human populations, including sensitive groups such as children, the elderly, and pregnant women, and uncertainties associated with these estimates. From this process, the likely probability and consequences of adverse effects from a contaminated site, both as it presently exists and at some future, desired state, are assessed. (For detailed discussions of risk and risk assessment, see reports issued by the National Research Council [1983; 1989; 1994a,b; 1996a].)
A risk assessment, therefore, is (or should be) a comprehensive assessment of the entire system of measures to reduce, isolate, or otherwise limit exposure to site contaminants. In contrast, a performance assessment is more limited in scope, usually referring to an evaluation of whether a system satisfies predetermined design or performance criteria. As such, it contributes to assessing technical capability, discussed below.
Risk assessments typically use mathematical models that seek to represent how various factors interact to determine risk. Performance assessments similarly aim to estimate the performance of controls intended to limit risk exposure. Information is fundamental to either type of model in that it permits realistic estimation of model parameters and helps to determine a model's conceptual and mathematical structure and the appropriateness of its simplifying assumptions. For example, the computer model RESRAD (see Appendix G) is often used in both risk and performance assessments to estimate the direct exposure to radiation at DOE sites. The model incorporates assumptions of environment homogeneity that may or may not be appropriate to the particular waste and site conditions to which it is being applied. Chapter 7 and Appendix G provide more details on the capabilities and limitations of mathematical models in addressing site risks.
As noted above, an important aspect of risk and performance assessment is uncertainty. Despite the desirability of having a high degree of confidence, uncertainties often arise, involving factors such as the following:
Present condition of contaminants. The present identity, amount, form, and distribution of contaminants often is uncertain, especially when access to contaminants (e.g., subsurface contaminants) is limited to sampling
and non-invasive techniques. Recent examples are the unexpected migration of plutonium (possibly in colloidal form) in groundwater at the Nevada Test Site (Kersting et al., 1999) and appearance of cesium-137 at the bottom of a 125-foot well in the Hanford Site (Rust Geotech, 1996). At the Nevada Test Site, there is considerable uncertainty as to the consequences of underground nuclear testing, including uncertainty about (a) the amount of contamination that now resides in groundwater, (b) the amounts and types of contaminant residues in the source term, (c) the amount and rate at which the contamination is mobilized by groundwater, and (d) the pathway(s) that the contamination may follow in the groundwater and the rates and concentrations associated with possible contaminant migration (see Appendix F). However, addressing these areas of uncertainty can raise new concerns. At the Hanford Reservation, for example, there has historically been great reluctance to drill additional bore holes that could help establish more accurately the extent of tank farm leakage for fear that such drilling could create new flow paths for subsurface contamination, exacerbating the condition of greatest concern (Conaway et al., 1997).
Future behavior of contaminants. Contaminants can migrate (typically through soil, air, or water, but also through the reuse of contaminated materials), and they sometimes move through complex ecological cycles that may involve numerous species of flora and fauna. As elaborated in Chapter 7 and Appendix G, contaminant migration patterns may be little understood and highly uncertain. The Hanford Groundwater/Vadose Zone Integration Project (U.S. Department of Energy, 1998c) (see Sidebar 4-1 in Chapter 4) may address significant uncertainties and data gaps in the current understanding of the inventory, distribution, and movement of contaminants in order to develop comprehensive risk assessments, with the vadose zone, groundwater, and the Columbia River as receptors, in support of ongoing site cleanup.
Future developments in society and technology. As noted in greater detail in the next chapter, the magnitude of societal or technological changes can be difficult, if not impossible, to anticipate or predict, particularly over the course of decades or centuries. Some such changes can lead to reduced risk, particularly when new developments in science and technology lead to new options for contaminant remediation. Other changes can increase risks by creating new exposure pathways or by bringing increased human populations into areas that were once considered remote. Just 150 years ago, for example, there would have been no concern about drilling into buried waste while exploring for or exploiting natural resources. In addition, U.S. metropolitan regions have roughly doubled in area over the past 25 years, with certain of these, like Denver, now expanding outward toward contaminated DOE facilities at Rocky Flat.
Uptake by humans and other species. Equally uncertain in many cases are the processes by which contaminants travel through and affect exposed organisms. In this regard, controversies continue concerning issues such as linear, no-threshold dose/response models or, in contrast, models based on the concept of hormesis (i.e., the concept that very low doses of toxic substances may sometimes be beneficial) (National Council on Radiation Protection and Measurement, 1995; United Nations Scientific Committee on the Effects of Atomic Radiation, 1993; Jaworowski, 1999). Moreover, the future situations in which humans and other species may be exposed to contaminants also present uncertainties, in part because the behavior patterns of future generations are difficult to predict.
Modeling limitations. As discussed further in Chapter 7 and Appendix G, mathematical models may oversimplify processes, they may use the wrong parameters and relationships among parameters, or they may embody the wrong conceptual structure for the problem at hand. Each of these possibilities creates uncertainty about the accuracy of descriptive or predictive mathematical models.
SCIENTIFIC AND TECHNICAL CAPABILITY
In the context of this report, technical capability refers to whether contaminant reduction and isolation measures can achieve site disposition goals—either final, end-state goals, or goals for a desired interim state. Scientific capability refers to our ability to understand and conduct the behavior of residual wastes and the environments in which they reside, thereby determining the efficacy of the contaminant reduction and isolation measures being employed, or to know upon which such measures we should rely. Scientific and technical capabili-
ties thus affect the balance among the three “legs of the stool,” by affecting the likely effectiveness of the contaminant reduction and isolation legs.
If the technical capability of contamination reduction is good, then cleanup for unrestricted future use may be possible, or if the technical capability of contaminant isolation is good, then controls on site use may figure somewhat less importantly. However, stewardship is likely to remain important because monitoring isolation effectiveness, and intervening if necessary, will have to remain a long-term institutional responsibility, as might additional decontamination of the isolated wastes as technologies capable of doing so become available. In contrast, if the technical capability to achieve either contaminant reduction or contaminant isolation is poor, then stewardship activities become all the more crucial. Theoretical and practical feasibility are important boundary conditions in specifying goals, helping to determine not just whether a goal can be met at all, but the extent to which it can be met (i.e., the extent to which risk reduction can be achieved).
The capabilities of technologies have theoretical limits. Thus, it is impossible to separate one substance completely from another. But, in most cases the limits of separations are not important because these limits are far below that which is typically specified as allowable. However, as our contaminant detection ability increases, smaller and smaller contaminant concentrations may cause a technology to fail to meet a remediation goal.
Much more common are limitations on the practical feasibility of contamination reduction or isolation technologies. These limitations, often grounded in basic scientific understanding and technical knowledge, reflect the current status of technology development. For example, it may not currently be possible to locate certain subsurface contaminants, to separate two substances from each other, or to design a barrier that we can assume with confidence will remain intact and compliant with regulations for the thousands, hundreds, or even mere tens of years that may be necessary. Some tasks are simply not possible at this time; others may go part but not all of the way toward meeting a remediation goal. For example, a waste form technology may reduce but not eliminate the migration of tritium or other radionuclides in the subsurface. There is no practical way to separate tritium from groundwater, and in many cases, dense non-aqueous phase liquids (DNAPLS) can not be removed from the subsurface (if, in fact, they can even be detected). At the Hanford Site, there are pump-and-reinject operations around strontium-90 plumes in Area 100 near the Columbia River, but their purpose is to retard migration rather than to remove the contaminants.
In many instances, scientific and technical research and development may eventually overcome limitations in practical technical feasibility if adequate time, expertise, and other resources are available. But in the meantime, limitations on the practical (including costs) as well as theoretical feasibility of technology can constitute a major constraint. The limitation of cost, while often an important factor, is treated separately below. Research and development to improve the feasibility of a technology can also yield lower-cost technologies and methodologies (National Research Council, 1999c).
Institutional capability is, conceptually, parallel to technical capability. It includes considerations about whether the organizations responsible for site remediation and management, the organizations responsible for oversight and enforcement, and other institutions such as the legal system have the ability to carry out their duties effectively over time. As with technical capability, institutional capability affects the balance among the three legs of the committee 's metaphorical institutional management stool. In particular, a fundamental question is: “To what extent are institutions able to carry out long-term stewardship activities that can be relied upon as part of the total management system for a residually contaminated site? Realistic estimates of institutional capability are thus an
important consideration in establishing interim and end state goals. Institutional capabilities and limitations are discussed more fully in Chapter 7.
There are two important points to stress: the problem of estimating institutional capability, and the lack of adequate framework and adequate empirical data. First, although realistic estimates of institutional capabilities are needed, these estimates are very difficult to make. The ability of institutions to perform stewardship activities reliably over the long term is highly uncertain. This ability has simply not been studied to the same extent as the technical aspects of site disposition, and even with further study, important uncertainties will remain. Second, institutional dynamics, like physical environmental processes, arise from complex interactions among numerous variables, many of which are poorly understood. These complexities may mean that additional data, while helpful, may still not result in the level of understanding that is possible with physical processes. Individuals and institutions may change at rates and in ways that make generalization difficult even when present-day situational aspects of institutional behavior are relatively well understood. Acceptance of a standard model's ability to describe particular phenomena is less common in the social sciences than in the biophysical sciences, and, in many cases, competing models will equally “explain” observed social and institutional phenomena. Past behavior will provide some indication of future behavior, but to date relatively little research funding has been directed toward studies to understand and predict institutional behavior concerning stewardship. Consequently, there are no widely agreedupon conceptual frameworks for providing assessments of institutions and their stewardship capabilities, nor is there an adequate database for making estimates of future institutional performance.
As used here, “cost” refers to the financial resources and other investments required to transition a waste site from its present state to a desired future state. Included are the costs of contamination reduction and isolation as well as stewardship activities. Cost should be understood not just in terms of money needed by organizations and individuals to perform specific duties or achieve specific ends, but also the “ opportunity cost” of then not having the committed resources available for other uses. The latter category can include time volunteered by citizens (e.g., as members of public interest “watchdog” organizations).
Effects of Cost on Site Disposition Decisions
Cost is a key factor (although certainly not the only factor) constraining the current ability to make U.S. Department of Energy (DOE) contaminated sites acceptable for unrestricted use (Probst and Lowe, 2000). For the DOE complex as a whole and for individual site disposition decisions, deciding where and how to spend limited financial resources is a critical contextual factor. At the individual site level, cost typically affects disposition decisions in four ways:
Cost concerns at the national level, particularly within the Congress, have had substantial impacts on the pace and timing of cleanup at some DOE sites. They have also led to changes in the way cleanup is being implemented, most notably through recent “privatization” initiatives. At some sites there has been concern that cleanup budgets are now competing with funding for site reuse through private-sector reindustrialization and other community redevelopment initiatives. Whether privatization and reindustrialization will serve to reduce costs (and financial risks) has been a controversial question, in particular the privatization experience with remediation of transuranic waste in Pit 9 at the Idaho National Engineering and Environmental Laboratory (U.S. General Accounting Office, 1997b) and with vitrification of high-level waste at the Hanford Site.
Cost is often a consideration—sometimes tacit rather than explicit—in determining the balance among the three sets of measures to achieve risk reduction (contaminant reduction, contaminant isolation, and stewardship). For example, it may be more cost-effective to achieve a specified future state by using a combination of contaminant isolation and stewardship rather than conducting expensive, more complete contaminant reduction measures. However, a future state that includes stewardship is not the same as a future state reached via more complete contaminant remediation, particularly if the latter would allow unrestricted access. The Nevada Test Site, for
example, would be very costly (if at all possible) to remediate, and DOE relies very heavily on the future of NTS as a ‘high security ' site as a rationale for not cleaning up many areas where the surface and surface environment is contaminated as a result of nuclear testing.
At a design level, cost is often an important factor in determining which of alternative techniques should be used to achieve a specific objective. For example, is grouting of waste much less expensive than vitrification, leaving aside other questions such as reliability and effectiveness? Are traditional “hands on” waste exhumation techniques less expensive than using robots, but at the cost of higher risk to the workers? Although computerized records take much less space than paper records and are much more accessible for future analysis by a large group of potentially interested parties, are computerized records less expensive to store and maintain, and what is their lifetime?
If the cost of achieving a desired future state is sufficiently large (regardless of the balance among the three sets of measures and of how each measure is designed), the goal of achieving that state may be abandoned at least temporarily and a more modest risk reduction goal may be specified. Alternatively, risk standards may become more lenient or stricter in the future based on a new understanding of risk and effects of dosages on persons and the environment; cost considerations thus may precipitate a tradeoff between future use goals and the stringency of regulations prescribing risk standards. As discussed below, the views of interested and affected parties may affect these tradeoffs.
In principle, calculating the monetary cost of a proposed set of site disposition measures is straightforward. One simply specifies which measures will be implemented, determines the amount of material, equipment, land, and labor that is required for each measure, obtains the unit price for the material, etc., and then “does the math.” In practice, however, cost estimates (like risk and institutional capability estimates) can have significant uncertainties:
Site characterization. If the site has not been adequately characterized, the actual problem may be very different from the one for which the cost estimate was prepared.
Technology. The contaminant reduction or isolation technologies may be experimental (and thus their costs may be difficult to estimate), their durability (and thus the frequency of incurring additional cost) unknown, or they may not work (requiring further investment to achieve risk reduction goals). The same can be said for stewardship activities. A 1995 DOE internal review of technical and cost assumptions for the Hanford Site tanks program concluded that too many first-of-a-kind technologies were required for remediation of the tank wastes to make realistic cost estimation possible (described in National Research Council, 1996d, pp. 22-23).
Duration. The time over which a site disposition measure will be needed (e.g., institutional controls, “pump-and-treat” technologies) may be uncertain or may have been erroneously estimated.
Scope. The full scope of the disposition effort may be difficult to estimate or may not have been taken into account. (e.g., the cost of off-site disposal of certain wastes may be unknown, the full cost of facility decontamination and decommissioning may have been overlooked, or the characterization of the contaminants in terms of types and amount may be erroneous.)
Pricing assumptions. The emergence of privatization efforts within DOE further complicates cost estimation. Under the DOE standard contracting practices, cost estimates are based on the estimated aggregate costs for the development and deployment of the technologies to be applied. Under privatization, DOE expects to pay the unit costs for the remediation services ultimately provided by private contractors.
Predictive economic assumptions. Assumptions will have to be made about individual price trends, general inflation rates, etc. These assumptions have inherent uncertainties, especially with attempts to forecast costs far into the future.
Despite these uncertainties, reasonably accurate cost estimates can, with some effort, be obtained for many site disposition decisions. In general, however, cost estimates for proven technologies to be applied within the near
future are more likely to be accurate than cost estimates of complex, long-term site disposition decisions where the technology that will be applied may still be in the development stage. Costs of the latter still need to be estimated, but the range of such estimates based on uncertainties must be recognized.
In addition to controversies arising over how much money should be spent, where, when, and in what ways, controversies can arise over cost estimates. Some conflicts can arise over the calculation methods discussed above. In addition, there are at least three other sources of cost estimate controversy:
Discount rates. In performing calculations about costs to be borne in the future, discount rates often are used to monetize the value of those costs in today's terms. The larger the discount rate, the lower the future cost will appear to be.
Hidden costs. Transaction costs and other hidden costs may be difficult to estimate, yet the experience to date with the Superfund program and the DOE site cleanup program suggests that these costs are often large.
Cost shifting. Costs may also be hidden by “cost shifting,” when responsibilities are shifted from one organization to another (e.g., from the federal government to state governments, or from governments to citizen watchdog groups) but are not adequately compensated.
LAWS AND REGULATIONS
As used here, the phrase “laws and regulations” includes the body of civil, criminal, and administrative law at all levels of government, including rulemaking pursuant to these laws, and compliance agreements. The disposition of contaminated sites is addressed at the federal and state level through programs and procedures established under statutes such as the Atomic Energy Act, the National Environmental Policy Act of 1969 (NEPA), the Uranium Mill Tailings Radiation Control Act (UMTRCA), the Resource Conservation and Recovery Act of 1976, as amended (RCRA), the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as amended (CERCLA), the Federal Facility Compliance Act, the Toxic Substances Control Act, the Clean Air Act, and the Safe Drinking Water Act (see Appendix E). Laws such as these specify goals and methods to be used in making and carrying out site remediation decisions. In addition, other federal and state laws (those concerning budgets and appropriations; property rights, responsibilities, and transfers; torts; contracts; insurance; etc.) provide a legal context within which these decisions take place. Federal facility compliance agreements (as used here, agreements between DOE, U.S. Environmental Protection Agency [EPA], and the state in which a DOE waste site is located) provide further context for these decisions by specifying schedules, budgets, and oversight arrangements to attain particular goals.
Flexibility and Accountability
An ideal legal and regulatory framework would allow flexibility, but require accountability while minimizing conflict. In practice, however, this balance is often difficult to achieve because laws and regulations (although not compliance agreements) are intended to be of general application and cannot anticipate specific situations. Some laws and regulations lean toward stipulating in detail what must or must not be done, while others lean toward establishing general standards and procedures while permitting a good deal of discretionary latitude. For example, the present (1999) statutory and regulatory framework of UMTRCA requires a design-based approach to contaminant isolation. It also requires government ownership of some sites forever. In contrast, the wording under CERCLA expresses a general preference for remediation (treatment of contaminants), addresses what must be done when federal land that has been contaminated is transferred, and acknowledges that institutional controls may be necessary in some situations. The UMTRCA is relatively prescriptive, whereas by comparison CERCLA is more open-ended.
Laws and regulations are always subject to interpretation and change. Formal changes typically occur by statute or through rulemaking; interpretations typically occur through court cases or through guidance documents and policy statements by the regulating or implementing agency. The impetus for change may come from a variety of sources: for example, increased use of a particular remedial approach (e.g., stewardship activities as a prominent component of site remedies); the emergence of new scientific and technical understandings (e.g., the widespread presence of dense non-aqueous phase liquids—DNAPLs —in groundwater with no adequate remedial technology to remove them); or an altered political climate (e.g., receptivity to arguments by responsible parties about the relative costs and benefits of regulatory compliance).
Federal facility compliance agreements are also subject to renegotiation and change. For example, the Hanford Triparty Agreement among DOE, the state of Washington, and EPA calls for a negotiated cleanup schedule. Failure to reach a negotiated schedule results in the opportunity for the state to unilaterally impose a cleanup schedule. One deadline for reaching a negotiated schedule, in this case for the tanks program, came and went with no schedule presented. Rather than imposing its own schedule, the state agreed to give DOE more time to try to negotiate one (Daily Environment Report, February 9, 2000, page A-4). Since changes to the legal and regulatory framework are inherently a political process, it is often difficult to predict how the framework will evolve. Compliance agreements are also subject to the political process.
VALUES OF INTERESTED AND AFFECTED PARTIES
As used in this report, interested and affected parties include individuals or groups that have an interest in site disposition but are not directly responsible for site management or oversight. A discussion of interested and affected parties is found in the report Understanding Risk (National Research Council, 1996a).2 The processes embodied in laws such as NEPA and CERCLA provide opportunities for broad public involvement through public meetings, public hearings, and written comments. In addition, in the mid-1990s DOE initiated the concept of “site-specific advisory boards,” which draw representatives from various interested organizations and population subgroups in the area surrounding a DOE facility to provide recommendations on environmental restoration and waste management decisions concerning the facility. Moreover, at many DOE facilities, groups have formed of their own accord to monitor remediation activity and promote their various interests and viewpoints.
Levels at Which Influence is Felt
The views of interested and affected parties can have important effects on how other contextual factors, such as cost and risk, are treated in site disposition decisions. They may influence site disposition decisions in varying directions and strength of influence at five levels of generality:
They may help to define risk levels specified in regulations.
They may influence priorities about which sites within a facility are addressed first, and to what extent (thereby also influencing the management of other waste sites within the facility).
They may help to specify a desired future state for a site, particularly in terms of its preferred future uses.
The term “stakeholders,” which is sometimes used as an equivalent to “interested and affected parties,” is often taken in practice to refer to those with material interests who, by virtue of their jobs as well as their personal well-being, have a stake in site disposition decisions (e.g., site managers and regulators, people living near the site now or in the future). Here, we use the broader and more inclusive term employed in a recent National Research Council report on risk decisions that “ . . . interested and affected parties . . . may include people from diverse geographic areas, ethnic, or economic groups and organizations. . . . The parties' concerns may focus on various possible forms of harm, not only mortality and morbidity, but also physical, social, economic, ecological, and moral effects. . . .” (National Research Council, 1996a, p. 87).
They may help to decide the relative balance of contaminant reduction, contaminant isolation, and stewardship activities to be used in achieving a desired future state for the site.
They may influence choices concerning specific approaches and techniques (e.g., a preference for vitrification over grouting, a desire to have deed restrictions as well as zoning, or an objection to the use of on-site incineration).
Varying Direction and Strength of Influence
Interested and affected parties do not always hold the same views; sometimes, in fact, they may be diametrically opposed. Nevertheless, at a given site and point in time there may be a view that becomes dominant, whether by virtue of its number of proponents, their outspokenness, or their influence over local politics and the local economy. In addition, those with management or oversight responsibilities for a site often live in the community in which the site is located and may, over time, develop close ties with local leaders who are seeking to influence site management decisions. Those responsible for site management or oversight may also change jobs within the community, crossing over to become local leaders and, in some cases, strengthening the dominant view.
In some cases, the dominant view may favor making a site acceptable for unrestricted use, even if funds are scarce and current technical capability is limited. In other cases, however, the dominant view may favor inexpensive remedies and rapid reuse, even if it means restricted use. At the former K-25 area (now the East Tennessee Technology Park) at the Oak Ridge Reservation, buildings are being aggressively marketed for lease by the Community Reuse Organization of East Tennessee (CROET). As an example of the lease arrangements, Industries leasing space in the building, formerly used for milling and fabrication, are responsible for cleanup of the areas they use, but only to 8 feet off the ground. They are required to keep their operations confined to below that level.
The dominant view may moderate, however, as information is shared among interested and affected parties. For example, many members of the community surrounding the Fernald Site in Ohio originally supported the removal of all contaminants from the site. After extensive fact finding and dedicated participation by interested and affected parties, a site remediation plan was developed and agreed upon that allowed the creation of an on-site waste disposal cell. Such possible changes in the preferences of the public and the makeup of the communities over time must be recognized.
In addition to varying directionality, there are varying degrees of strength in influence. In some instances the input of interested and affected parties has been pivotal to site disposition decisions (e.g., the goals for removing waste from Hanford Reservation tanks, the decision to cap certain waste burial grounds at Oak Ridge Reservation in Tennessee, and the industrial reuse of parts of the Mound Plant in Ohio). In contrast, there are situations where the views of interested and affected parties have seemingly had little effect on site disposition decisions.
A number of other sites can influence disposition decisions concerning the waste site in question. These other sites can be categorized as:
nearby contaminated sites;
nearby property outside the facility;
receptor sites; and
Each is discussed below.
Nearby Contaminated Sites
In many cases, contaminated sites are located within a larger contaminated area. For example, waste burial grounds tend to be built close to each other to take advantage of natural features, to facilitate the burial grounds'
operation, and to make security measures easier. In addition, if waste sites have leaked, nearby contaminated soil and water may come to be viewed as a distinct contaminated site. The close juxtaposition of contaminated areas or of contamination problems of qualitatively different types can both complicate remediation planning and limit the ability of cleanup goals to be achieved. Groundwater does not respect site boundaries, a reality that may necessitate a broader context than that of the individual site (or “operable unit”) for specifying the desired future state. The implication for long-term stewardship is that the remediation of individual sites may be directed at end uses that, if implemented, would have high probabilities of failure given the larger site context.
Nearby Property Outside the Facility
DOE facilities do not exist in isolation. Each is surrounded by property (land and/or water) that is not under DOE control. To the extent that a waste site is near the facility boundary or has contaminants that may migrate across the boundary, this outside property can affect and be affected by the waste site. Outside property affects disposition decisions because it may present potential for exposure to contaminants. Actions on property outside the waste site (e.g., a more intensive use of a buffer zone or use of resources such as water flowing from the site) may increase the possibility of human exposure to contaminants. For example, sites in the arid western U.S. such as the Nevada Test Site were selected in part on the assumption that nearby population density and water demand would remain low, but the rapid population increase in recent decades in Las Vegas, Nevada, with a consequent expansion of its water demand and settlement boundaries, is clear evidence that this assumption may be wrong. To deal with greater exposure possibilities arising from changes in off-site activities, more elaborate measures (contaminant reduction, contaminant isolation, and/or stewardship) may be necessary on site.
In addition, changes in the type and intensity of surrounding land and water use can affect the physical characteristics of the waste site in question. For example, changes in water use can affect hydrological conditions at the waste site, which can in turn affect the performance of contaminant isolation technologies. At the Hanford Site it has been suggested that irrigated agriculture in areas to the north of the City of Richland could have the beneficial effect of creating a groundwater mound that could help assure protection of groundwater in nearby industrial areas from site-derived contaminants. Similarly, macroscale changes such as global climate change may have unanticipated effects on the waste site.
Any remediation activity produces primary wastes (e.g., high-level waste forms and low-level and mixed waste packages) and secondary wastes (e.g., contaminated equipment and fluids, incinerator ash) that must be managed, and contamination reduction by waste removal may generate a large amount of additional waste. Often, the destination of these wastes is another facility (owned either by DOE or a private company), which may be far from the originating site. As a consequence, while risks at the originating site usually are decreased (“usually, ” because cleanup and transportation worker exposure may entail risks), risks may be increased at the receptor site as well as along transportation routes. Receptor sites can affect disposition decisions at the originating site in a number of ways. Of these, two stand out.
First, the risks may not be acceptable to the receptor site, as well as to those along the transportation routes. For example, the Tennessee state government has taken the position that use of the mixed waste incinerator at the Oak Ridge Reservation is to be restricted to on-site wastes except in “emergency” situations. As another example, the residents of Santa Fe, New Mexico, concerned about the transport of transuranic wastes through Santa Fe to the Waste Isolation Pilot Project (WIPP) site near Carlsbad, New Mexico, successfully initiated a movement to build a bypass.
Second, even if the receptor site does accept the waste, its waste acceptance criteria can shape decisions concerning contaminant reduction processes at the originating site. For example, the calcined high-level tank wastes stored at the Idaho National Engineering and Environmental Laboratory (INEEL) do not meet waste acceptance standards for the proposed repository at Yucca Mountain, Nevada, and must therefore be further processed, at possibly another site (one option would be to ship the wastes to the Hanford Site for vitrification). As
DOE has recognized in recent “system integration” efforts, the complex-wide implications of various disposition decisions —including cost and other resource efficiencies, net risks, and the equitable distribution of risks—need to be considered but are likely to be fraught with controversy.
By now, the cleanup of contaminated DOE facilities and other sites is becoming a familiar subject. Some precedents have been established for site disposition for considerations such as relative reliance on contaminant reduction, contaminant isolation, and stewardship under particular site conditions. While these precedents are not usually determinative, they often influence site disposition decisions, both as contemplated by DOE and its contractors and as guided by regulators. Following precedents can be an efficient decision-making device; it can minimize having to reenact expensive and time-consuming decision processes on a case-by-case basis, only to end up with the same answer. Remediation activities produce primary wastes (e.g., high-level waste glass logs and low-level waste packages) and secondary wastes (e.g., contaminated equipment and fluids, incinerator ash). A generic example is the classification of radioactive wastes that then leads to a specific disposal technology without much debate (e.g., uranium mill tailings go into piles; low-level waste goes to existing shallow land burial sites).
Rigorous adherence to precedent, however, can result in inappropriate or distinctly sub-optimal decisions. Seemingly similar sites may in fact have important differences that will affect remediation. For example, techniques to remediate sandy soils may work poorly in clayey soils. In addition, continuing to use a well-established technology can preclude the development and deployment of more effective, less expensive technologies (National Research Council, 1999b). Thus, while precedents can expedite site disposition decisions, they need to be used judiciously, to ensure that they are relevant and appropriate.
INTERACTION AMONG CONTEXTUAL FACTORS WITHIN A CLIMATE OF UNCERTAINTY
For purposes of simplicity, each of the seven contextual factors discussed in this chapter—risk, scientific and technical capability, institutional capability, cost, laws and regulations, interested and affected parties, and other sites—has been treated separately. In actuality, however, these factors interact, and they often cannot be neatly distinguished. For example, technical capability questions may arise at both a site to be remediated and at a prospective receptor site, as may issues concerning risk, cost, regulations, and the views of interested and affected parties. In site disposition decisions, then, balancing among the “three legs of the stool” typically is driven by the interaction of and tradeoffs among these contextual factors. In other words, at any stage in the long-term disposition of the waste site, both the types of contaminant reduction, contaminant isolation, and stewardship measures and the extent of reliance on any one set of measures will be affected by the contextual factors discussed in this chapter.
Moreover, as suggested in this chapter, site disposition decisions often are reached in a climate of uncertainty affecting the available choices as well as the contextual factors. Uncertainties can arise concerning the site at present (e.g., its characterization, the efficacy of contaminant reduction and contaminant isolation measures); the site's surrounding physical and social environment at present (e.g., external exposure pathways, off-site potentially exposed populations and their sensitivity to contaminants); the site in the future (e.g., changes in residual contamination over time, changes in the long-term efficacy of contaminant reduction and isolation measures as well as stewardship measures); and the site's surrounding physical and social environment in the future (e.g., changes in the surrounding physical environment and its use, leading to on-site changes as well as to changes in off-site human and ecological exposure to contaminants). Many of these uncertainties are exacerbated by technical and institutional limitations. These limitations, and corresponding capabilities, are discussed in the following chapter.