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 242
A Risk-Management Strategy for PCB-Contaminated Sediments 8 Making Decisions This chapter presents the fourth stage in the risk-based framework for managing the risks associated with PCB-contaminated sediments. At this point in the process, general risk-management goals would have been established, the site would have been characterized in terms of hydrodynamics, geology, and other physical and chemical factors, and the nature and extent of the PCB contamination at the site should have been delineated. The human health, ecological, social, cultural, and economic risks for the site have also been identified. Possible management options, both technical and nontechnical, have been explored, and the risks for each option have been assessed as shown in Table 7–3. Now a decision must be made on which management option or combination of options is most likely to achieve the risk-management goals established in stage one of the framework (Chapter 5), based on the assessment of risks posed by the contamination (Chapter 6) and those associated with each option (Chapter 7). The difficulty in selecting the best risk-management strategy for a site stems from many factors, including the differing levels of contamination at the site, the lack of uniformity in the sediments themselves (e.g., depth and debris cover), the varying ecology (human and environmental) at different locations around the site, and the sheer magnitude of many PCB-contaminated sites, some of which can cover many square miles. Because of the unique character of each site, determining the most appropriate course of action can
OCR for page 243
A Risk-Management Strategy for PCB-Contaminated Sediments Consideration of Options The paramount consideration for PCB-contaminated sediment sites should be the management of overall risks to humans and the environment rather than the selection of a remediation technology (e.g., dredging, capping, or natural attenuation). Indeed, the lack of consideration of these risks is one of the major impediments to the adoption of a successful management strategy. There should be no presumption of a preferred or default risk-management option that is applicable to all PCB-contaminated-sediment sites. A combination of technical and nontechnical options is likely to be necessary at any given site. be difficult, not only for the designated decision-makers but also for the other affected parties who will have to implement and live with the decision. Affected parties might assume that the availability of a wealth of site-specific data, well-conducted human health and ecological risk assessments, and a thorough review of the risks associated with potential risk-management options will automatically lead to a determination of the most-effective and acceptable risk-management strategy. However, that assumption is often not the case, because decision-makers are dealing with a multivariate system, which involves a diverse community with differing expectations, interests, risk tolerance, and willingness to pay. This complexity has been a major contributor to the slow progress on risk management at many PCB-contaminated-sediment sites to date. New procedures are needed to accommodate the multivariate complexity at contaminated sites. In this chapter, the committee summarizes the regulatory environment in which any decision-making process on a PCB-contaminated site must take place, reviews the various components of the decision-making process, discusses how these processes relate to the risk-management framework described in this report, and shows how the process may be facilitated. REGULATORY REQUIREMENTS The need to comply with various federal and state regulations when managing a PCB-contaminated-sediment site cannot be ignored. The regulations involved in the risk-management strategy for PCB-contaminated sedi-
OCR for page 244
A Risk-Management Strategy for PCB-Contaminated Sediments ments can complicate its development and impede its implementation. The NRC report (1997) on contaminated marine sediments analyzed the regulatory and legal challenges posed by contaminated sediments and provided a summary of the current regulatory requirements for the management of contaminated marine sediments. The analysis and conclusions provided in this NRC report are equally relevant to the risk management of PCB-contaminated sediments and are discussed briefly below. Regulatory Overlap As explained in the 1997 NRC report, several federal laws (CERCLA, CWA, RCRA, MPRSA1) have been enacted that deal with health and environmental issues surrounding the presence of contaminated sediments in navigable and nonnavigable waters. These laws were not designed specifically to manage contaminated sediments but rather deal with issues such as water quality and the disposal of hazardous waste. These laws are implemented through a variety of often contradictory or overlapping federal and state regulations. In addition to federal agencies, such as EPA and the U.S. Army Corps of Engineers (USAGE), states also exercise important authority related to water-quality certification, coastal-zone management, and use impairments for water bodies. Many states also have their own Superfund and RCRA-type laws which may not be entirely consistent with federal laws. In some cases, local laws might also apply. State environmental, health, and transportation agencies might play a role in the management of contaminated sediments. The principal federal agencies involved in management of contaminated sediments are the following: EPA, which is responsible for implementing the Superfund program under CERCLA and has major site designation, regulation development, and veto responsibilities under the CWA and MPRSA. U.S. National Oceanic and Atmospheric Administration, which assesses the potential threat of Superfund sites to coastal marine resources and has important responsibilities for research under the MPRSA and review and comment under CWA and MPRSA. 1 In CERCLA is the Comprehensive Environmental Response, Compensation and Liability Act (Superfund); CWA is the Clean Water Act; RCRA is the Resource Conservation and Recovery Act; MPRSA is the Marine Protection, Research, and Sanctuaries Act.
OCR for page 245
A Risk-Management Strategy for PCB-Contaminated Sediments USAGE, which assists in the design and implementation of remedial actions under Superfund and has responsibilities for dredged material under the CWA, MPRSA, and Rivers and Harbors Act. U.S. Fish and Wildlife Service, which acts as a federal trustee at contaminated sites under the Natural Resource Damage Act. If a decision is made to dredge contaminated sediments, several laws affect their disposal on land or in the water. It is currently necessary to secure different types of permits for the placement of sediment in navigation channels or ocean waters as part of the construction of land or containment facilities (under the Rivers and Harbors Act), the dumping of sediments in the ocean (under MPRSA), the discharge of sediments in inland waters or wetlands (CWA), and the containment of contaminated sediments on land (RCRA). Regulatory Constraints Existing regulations complicate and can impede, but do not necessarily prevent, implementation of the risk-based framework for the risk management of PCB-contaminated sediments. Regulatory differences need to be acknowledged and, if possible, resolved early in the management process so that all participants are working toward a common goal. For example, although EPA may be the lead regulatory agency for risk management at a site, the U.S. Fish and Wildlife Service may be the trustee for a natural resource damage assessment and has very different regulatory concerns and needs. However, it may be necessary to complete the risk assessments and determine what management options before all applicable laws are identified. For example, RCRA may not be an applicable law if natural attenuation is the selected management option or the MPRSA may not be applicable for the dredging of river sediments with land disposal. The risk-management framework is not intended to supplant existing regulatory processes; rather it provides a consistent and comprehensive approach to facilitate their implementation. Using this framework will not only satisfy the requirements of the CERCLA remedial-investigation and feasibility-study (RI/FS) process but will also enhance it by encouraging the use of all available data on a site. The community surrounding the site will be included early and consistently in the process, and a broader assessment of the various risks the contamination poses to humans and the environment will be provided. The current regulatory regime focuses on the type of sediment management activity—removal, containment, or treatment—and not on the manage-
OCR for page 246
A Risk-Management Strategy for PCB-Contaminated Sediments ment of all risks to humans and the environment. As noted in the 1997 NRC report, the mechanisms of the regulatory process in a given situation depend on where the sediments are located; where they will be placed; the nature and extent of the contamination; and whether the purpose of removing or manipulating the sediment is navigation dredging, environmental cleanup, site development, or waste management. Each set of laws uses a different approach to assess management options for contaminated sediment, and none considers fully all the risks (NRC 1997). The regulatory process under MPRSA places primary emphasis on the intrinsic toxicity of the constituents of dredged material without full consideration of site-specific conditions (e.g., proximity to shellfish beds, other sensitive receptors, food-chain carriers, or the containment of contaminants by an engineered clean cap) that might influence the impact on various organisms. Risk reduction is the goal of the Superfund remedial-action program. Site-specific remedies are chosen on the basis of exposure assessments during the feasibility study, and management options are identified on the basis of their capability to reduce risks of exposure to an acceptable level. The final selection of a risk-management strategy now involves choosing the most cost-effective alternative, not necessarily the alternative that will have the broadest community acceptance. Finally, the current regulatory regime places a presumption on action-oriented approaches to risk management at PCB-contaminated sites. Decisions under MPRSA and CWA are made when sediments are proposed for dredging and placement in inland or ocean waters. Remedy selection under Superfund places a preference on management approaches that remove contaminants from the environment (EPA 1991). In addition to Superfund’s nine criteria for evaluating management options (Box 8-1), there is a general statutory preference for treatments that “permanently and significantly reduce the…toxicity or mobility” of contaminants (section 121(b) of CERCLA). Section 121 also establishes off-site transport and disposal of untreated contaminated sediments as the least desirable alternative (Renholds 1998). Natural attenuation or the in-place or ex situ capping of contaminated sediments does not have the requisite quality of “permanence”—in the same sense that the destruction or detoxification of sediment contaminants have permanence. COMPARATIVE DECISION-MAKING Science has a critical role to play in the decision-making process. Technical considerations should not be excluded from the decision-making process
OCR for page 247
A Risk-Management Strategy for PCB-Contaminated Sediments nor should they totally control the process. To make rational decisions, decision-makers need to have accurate estimates of the potential exposures; effects; and subsequent human, ecological, social, economic, and cultural risks. Thus, it is the responsibility of scientists (including economists and other social scientists) and engineers to present their risk-assessment results and their estimates of engineering feasibility and effectiveness in an unbiased, clear, and systematic manner. One of the inherent problems when comparing risks of different types (e.g., economic risks with health risks) is that there is no scientific methodology to do so (Davies 1995). Implicit in any such comparisons of different types of risk are the values of the decision-makers and other affected parties. The regulatory environment, in which such values are considered and risk-management decisions are made, must also be considered, as noted above. Decision analysis, and ultimately, decision-making, at PCB-contaminated sites might require several types of analyses to assess the costs, benefits, effectiveness, and risks associated with each potential management strategy. In this chapter, the committee presents a discussion of decision-making with a description of the RI/FS process as practiced by EPA. This process is followed by EPA and other regulatory agencies at Superfund sites. The committee then provides a brief description of some approaches that may be used by EPA in the RI/FS process and that may be used in a more general sense by all affected parties to develop a risk management strategy. These approaches include cost-benefit analysis (NRC 1997); risk tradeoffs (Graham and Weiner 1995; NRC 1997), and risk ranking (Graham and Hammitt 1995). Finally, the decision-analysis process, which incorporates information from the cost-benefit, risk tradeoffs, and risk-ranking exercises is discussed (NRC 1997). The committee recognizes, as with other stages in the risk-management framework, that selection of an approach to decision-making is dependent on the needs and values of the affected parties and the specific situation at a PCB-contaminated-sediment site. The RI/FS Process at EPA At present, the primary decision-making process used by EPA for managing National Priority List (Superfund) sites, is the RI/FS process (as described in Chapter 3 of this report) (EPA 1991). Although written specifically for Superfund sites, this process is also used by states and other responsible parties and can be applied to non-Superfund sites as well. In the RI/FS process, EPA, another federal or state agency, or a potentially responsible party (PRP) conducts a screening, a baseline risk assessment, or both (as described
OCR for page 248
A Risk-Management Strategy for PCB-Contaminated Sediments in Chapter 6) and characterizes the site to develop and analyze a preliminary list of management options. These options (usually four to five of them) are described in following terms: (1) volume of material to be remediated; (2) implementation of requirements and timetables; (3) method of remediation and general response actions; (4) remediation technologies (treatment or containment) and process options; (5) monitoring procedures; (6) capital, operational, and maintenance costs; (7) need for 5-year review; and (8) the applicable or relevant and appropriate requirements (ARARs) that are triggered by this option, such as land-disposal restrictions. A detailed analysis of the alternatives is then conducted, and the alternatives are compared with nine EPA evaluation criteria (see Box 8-1). The alternative that best meets the criteria is then presented to the public for a comment as the proposed risk-management plan. After a public comment period, the risk-management plan, modified as necessary to accommodate the comments received, becomes a Record of Decision if the site is on the Superfund National Priorities List. However, as heard by this committee during the public sessions, this process has not received general approval. Many affected parties stated that decisions appear to be made arbitrarily by the regulatory agencies with little or no input from those most affected, that public comments received during the public comment period do not appear to have much, if any, influence on the decisions, and that all available information and all risks (human health, ecological, social, economic, and cultural) do not appear to be considered by the regulatory agencies during the RI/FS process. Nevertheless, the committee believes that the RI/FS process is a generally useful mechanism for BOX 8–1 EPA Evaluation Criteria for Remedial Action Alternatives Overall protection of human health and the environment Compliance with ARARs Long-term effectiveness and permanence, including magnitude of residual risk and adequacy and reliability of controls Reduction of toxicity, mobility, or volume through treatment. Short-term effectiveness Implementability Costs State (support agency) acceptance Community acceptance Source: EPA (1991)
OCR for page 249
A Risk-Management Strategy for PCB-Contaminated Sediments gathering the necessary site-specific technical information at a contaminated site and for providing a blueprint for the data collection and analysis efforts. The RI/FS process is used consistently by EPA and many other regulatory agencies, and the regulated industries are familiar with the process as well. However, EPA guidance for the RI/FS and ARARs processes has been criticized as being frequently too vague or inconsistently applied. The committee concludes that it also might also be too restrictive to accommodate the various risks that must be assessed and evaluated at PCB-contaminated sites and to accommodate the need for involvement of all affected parties in the risk-management process. To address many of the criticisms of the RI/FS process, the committee recommends that increased efforts be made to provide the affected parties with the same information that is to be used by the decision-makers and to include, to the extent possible, all affected parties in the entire decision-making process at a contaminated site. In addition, such information should be made available in such a manner that allows adequate time for evaluation and comment on the information by all parties. Cost-Benefit and Cost-Effectiveness Other decision-making tools are available to the decision-makers and affected parties: cost-benefit analysis and cost-effectiveness analysis. Cost-benefit analysis is based on first identifying all positive (benefits) and negative (costs) impacts of an action, with the impacts quantified in a common (dollar) unit. The set of actions that leads to the largest net benefit is identified. Cost-benefit analysis is effective for evaluating management strategies as it combines risk and cost information to determine the most efficient allocation of resources; however, this type of analysis may be extremely difficult to use when the benefits and costs (risks as well as monetary) are not easy to estimate or calculate (NRC 1997). Cost-effectiveness analysis identifies the least costly set of actions that achieves a given goal or, rarely, the set of actions that leads to the highest benefit for a given cost. Cost-effectiveness analysis is a more general approach than cost-benefit analysis. Any risk-management strategy that maximizes net benefits is considered to be a cost-effective solution. If one strategy can achieve the same level of benefit as another strategy but at a lower cost, the former strategy has a higher net benefit. Such analysis does not require that the costs and benefits be expressed in common units. The advantage of cost-benefit and cost-effectiveness analyses for contaminated-sediment sites is that they allow the comparison of very different risk-management options (e.g., institutional controls versus dredging) on
OCR for page 250
A Risk-Management Strategy for PCB-Contaminated Sediments an equal basis across sites. They also have the advantage of transparency of analysis and many assumptions, thus making them accessible to examination, critique, and reassessment through sensitivity analysis when some parameters are uncertain. These types of analyses are best viewed as providing input into a more complete decision-making process rather than providing the single decision criteria. The RI/FS process discussed above includes a consideration of cost-effectiveness analysis. Risk Ranking Any decision on how to manage a PCB-contaminated site should follow from an effort to achieve frank and open discussions among the affected parties after the risks identified for each risk-management option have been reviewed. As discussed in Chapter 7, it is helpful if the various risks for each of the options have been presented in a consistent fashion, as shown in Table 7–3. This table provides a mechanism by which each of the risks for the management options may be compared and ranked by the affected parties and the decision-makers. Several methods are available for ranking risk (Graham and Hammitt 1995). These methods include the following: Ranking risks associated with management options and baseline risks. Ranking risks according to the expected value of risk reduction. Using uncertainty as a source of information. Ranking risks according to target risks (e.g, health risks from PCB-contaminated sediments) and competing risks (e.g., health risk from not eating fish). Ranking risks according to resource costs and savings (cost-effectiveness analysis). However, to do this ranking in the most objective manner, the criteria for assigning values to the various risk categories (e.g., what constitutes a high short-term ecological risk or what cost is important) should have been established in stage one of the framework when the risk-management goals were identified and priorities were set, or, at the very least, in stage two of the framework during the risk assessment. It might be helpful to have each of the affected parties rank each management option and then compare and discuss the rankings with the goal of reaching a consensus on the best options or combination of options to minimize the overall risks at the site. The NRC Committee on Contaminated Marine Sediments (NRC 1997) presented, as an
OCR for page 251
A Risk-Management Strategy for PCB-Contaminated Sediments example of one approach to decision-making, comparative analysis of the remediation technologies and options that might be used for marine sediments (Table 8–1). When considering this table, however, it must be remembered that these rankings are relative only and that the values are subject to change (i.e., a pilot technology in 1997 might be in commercial use in 2001) and site-specific conditions. As that committee noted, no single technology scored the best in all categories. Furthermore, unlike Table 7–3, Table 8–1 does not consider any of the risks associated with the technologies. Risk Tradeoffs Even when risk-management efforts involve relatively nondisruptive activities, possible health, ecological, societal, cultural, and economic risks should be considered. One limitation of the current RI/FS process as practiced by EPA is that risks other than human health and ecological risks receive little consideration in the decision-making process. Furthermore, limiting involvement of all affected parties in the process also means that a thorough comparison of the total risks at a site might not influence the risk-management decision. The methods by which various types and levels of risks might be compared have been studied (Graham and Wiener 1995). With regard to PCB-contaminated-sediment sites, risks to human health and wildlife are considered to be target risks. Risks, such as economic or cultural risks, that stem from the target risks, are considered to be competing risks. Affected parties must be able to weigh and tradeoff these risks to make a decision on what is the best risk-management strategy. For example, although it might seem prudent to recommend avoidance of consumption of PCB-contaminated fish, there are potential adverse health impacts associated with the recommendation. Epidemiological evidence suggests that consumption of fish improves human health (TERA 1999). In addition, a representative of the Mohawk tribe stated to the committee that the avoidance of fish consumption had disrupted the tribe’s cultural tradition of fathers training sons to fish and had led to adverse health effects by reducing the physical activity of male tribal members (Ken Jock, personal commun., 1999). Thus, it seems reasonable to ask if avoiding consumption of fish with low concentrations of PCBs is beneficial or detrimental to overall human health. When considering possible risk tradeoffs, several comparisons may be made between the target risks and the competing risks based on whether the countervailing risks are to the same or different populations and of the same or different type (Graham and Wiener 1995). Risk transfer occurs if the target risks are of the same type but moved from one medium to another—for
OCR for page 252
A Risk-Management Strategy for PCB-Contaminated Sediments TABLE 8–1 Comparative Analysis of Technology Categories Approach Feasibility Effective Practicality Cost INTERIM CONTROL Administrative 0 4 2 4 Technological 1 3 1 3 LONG-TERM CONTROL In Situ Natural recovery 0 4 1 4 Capping 2 3 3 3 Treatment 1 1 2 2 Sediment Removal and Transport 2 4 3 2 Ex Situ Treatment Physical 1 4 4 1 Chemical 1 2 4 1 Thermal 4 4 3 0 Biological 0 1 4 1 Ex Situ Containment 2 4 2 2 SCORING 0 <90% Concept Not acceptable, very uncertain $1,000/yd3 1 90% Bench $100/yd3 2 99% Pilot $10/yd3 3 99.9% Field $1/yd3 4 99.99% Commercial Acceptable, certain <$1/yd3 Note: For each control and technology, the four characteristics were rated separately on a scale of 0 to 4, with 4 representing the best available (not necessarily the best theoretically possible) features. The effectiveness rating is an estimate of contaminant reduction or isolation, and removal efficiency scores represent a range of less than 90% to nearly 100%. The feasibility rating represents the extent of technology development, with 0 for a concept that has not been verified experimentally and 4 for a technology that has been commercialized. The practicality ranking reflects public acceptance; 0 means no tolerance for an activity, and 4 represents widespread acceptance. The cost ranking is inversely related to the cost of using the control or technology (excluding costs of monitoring and so forth). Source: NRC (1997).
OCR for page 253
A Risk-Management Strategy for PCB-Contaminated Sediments example, dredging might remove PCBs from the sediments but increase PCBs in the water column. Risk offsets are when the risks are the same in the same target populations as might occur when either dredging or capping kill a benthic community—population mortality occurs with either management option. The fish-consumption example above illustrates risk substitution where one type of outcome (risk of health effects from consumption of PCB-contaminated fish) is replaced by another outcome (risk of heart disease from lack of fish consumption). A framework for comparing the health risks associated with eating fish contaminated with such materials as PCBs versus not eating fish has recently been published; the public-health implications of such risk substitution are also discussed (TERA 1999). Finally, target risks can be transformed, resulting in a different outcome to a different population. Transformation might occur if the risks to reproduction of birds at one contaminated site are compared with the risks of immunological effects in humans who lived near a sediment disposal site. Another example might be the economic risks to farmers if their dairy cows are believed to produce PCB-tainted milk. The concept of voluntary versus involuntary risks and risks to special groups, such as children and endangered species, must also be factored into consideration of risk tradeoffs. Affected parties will be required to consider each type of risk for a PCB-contaminated-sediment site and possibly several permutations for each risk tradeoff type. By considering the various risks in broad terms of public and ecosystem health, it should be possible to make decisions that have net benefits on the community. An important factor in achieving a decision that works for all the affected parties is the consideration of the willingness of different affected parties to accept the various risks. Not all parties are equally affected by different risks, and some parties are disproportionately affected and thus might be unwilling to accept a risk that they primarily must bear. For example, many local communities are unwilling to accept a “beneficial” use or application of sediment removed from a contaminated river even if the sediment has been treated to reduce contaminant levels. Such uses might include inclusion of sediment in construction material or the building of a confined disposal facility that may provide new habitat. The communities where the sediment would be burned or where sediment-containing construction materials are used are often unwilling to accept the risks of the air emissions or the risks of contaminants leaching from the construction material even if the risk is considered low or “acceptable.” They are likely to oppose such plans especially if they are not included in the discussion of options and tradeoffs before a decision is made. If such tradeoffs are to be considered, representatives of those directly affected by the risks, such as the people who live downwind of the cement kiln, should be included in the discussion of the risks and tradeoffs.
OCR for page 254
A Risk-Management Strategy for PCB-Contaminated Sediments Decision Analysis Decision analysis is a computational tool that might be of use when evaluating, comparing, and ultimately selecting a risk-management strategy. It can be used to integrate the various aspects of the risk-management process described above. Aspects include risk and site assessment, economic assessment, and technical feasibility studies to estimate the outcome of possible management strategies (NRC 1997). Decision analysis also incorporates the results of the comparative risk-assessment analyses described above: cost-benefit and/or cost-effectiveness analyses, risk ranking, and risk tradeoffs. It has the advantage of formally accounting for uncertainties that are inherent in the risk assessments at the very least and of being reproducible. Furthermore, it allows users to modify the computations to ascertain how slight changes in the various risk parameters might affect the outcome. Such changes in scenarios might have profound impacts on the decision-makers and affected parties as they determine the most effective and acceptable risk-management strategy. The NRC report on contaminated marine sediments (NRC 1997, Appendix E) provides a hypothetical test case applying decision analysis to the risk management of a hot spot at a contaminated site. Although technical in concept and complex in execution, decision analysis is a valuable approach for evaluating competing management options at a PCB-contaminated-sediment site. Decision analysis is also more suitable for decision-making in the multivariate context generally associated with the management of PCB-contaminated-sediment sites. FRAMEWORK CONSIDERATIONS The committee has concluded that all risk-management strategies will be multifaceted. An advantage to using the Presidential/Congressional Commission on Risk Assessment and Risk Management’s (PCCRARM 1997) framework recommended by this committee is that affected parties are encouraged to consider a broad array of risk-management options, often resulting in solutions incorporating a variety of technological and nontechnological methods at a site rather than seeking the elusive “silver bullet.” Dredging or other technologies should be considered when developing a risk-management strategy, but focusing them without proper consideration of all options can lead to further issues at the site with a resulting delay in implementation. Therefore, although a particular technology might pose high risks in one area (e.g., dredging might have large, short-term ecological impacts), it might be appro-
OCR for page 255
A Risk-Management Strategy for PCB-Contaminated Sediments priate for use in a high-risk situation, such as a large hot spot. It also may be used for a limited amount of time if the technology is very effective in reducing the immediate risks or meets other criteria, such as low cost. It might be possible for all affected parties to discuss each of the risks at a site and identify the best options for managing both short- and long-term risks. At this point in the decision-making process, tradeoffs might be required to achieve consensus. Some affected parties might feel that no cost is too much to achieve a complete cleanup of a site but they might accept the reality that funds are not unlimited and that achieving a zero level of contamination is impossible. Others might be willing to forgo eating fish from the area if habitat for the fish can be restored and a catch-and-release program is instituted. At other sites, it might be imperative to reduce the contamination in the sediment to address immediate human health or ecological risks, and some risk-management strategy using a combination of technologies and other options must be implemented quickly. In that case, a phased approach consisting of an immediate response followed by a long-term response might be best. There is a presumption that removal of PCBs from a site will reduce a source of exposure of PCBs to the aquatic environment. But that is true only if PCB contamination at a site provides the major source of exposure. If there are other environmental sources contaminating the site, site remediation might have little or no impact on total risks. For example, while 40% of the Great Lakes shoreline is considered to be impaired by PCB contamination of sediments, almost 50% of the shoreline is contaminated by atmospheric deposition of PCBs and 30% is impaired by land disposal of PCBs (Muno 1999). Non-point sources, such as atmospheric deposition or land runoff, can have a substantial impact on the effectiveness of particular risk-management strategies to reduce total exposure. Any stage of the framework may be revisited as new significant information becomes available. Therefore, the greater the understanding and documentation of the site and the risk-management goals and the risks associated with the PCBs at the site and those associated with their management, the more readily new information may be incorporated into the framework without the need to “start over.” However, this new information must be understood to have an impact on the process or site—for example, simply identifying a new animal study on PCBs that does not affect the hazard assessment is not sufficient to delay the development and implementation of the risk-management strategy. Modifications to the risk-management strategy may be considered in light of any new compelling information either to increase or to decrease the strategy requirements (e.g., to require more monitoring or a decrease in the area to be dredged).
OCR for page 256
A Risk-Management Strategy for PCB-Contaminated Sediments The committee recognizes that this risk-based framework is ideally used at a newly identified contaminated site; in reality, however, most PCB-contaminated sites are already in the process. At sites where the risk-management process has not been completed and is the subject of contention, the committee urges the lead federal or state agency, to consider whether the participants involved at a contaminated-sediments site might use this framework to resolve a stalemate over site management. Conflict resolution might be a large factor in the decision-making process. The committee cautions that the use of the framework or other risk-management approach should not be used to delay a decision at a site if sufficient information is available to make an informed decision. Particularly in situations in which there are immediate risks to human health or the ecosystem, waiting until more information is gathered might result in more harm than making a preliminary decision in the absence of a complete set of information. The committee emphasizes that a “wait-and-see” or “do-nothing” approach might result in additional or different risks at a site. Most PCB-contaminated sites have had some risk-management activity, even if only an acknowledgment that PCBs are present in the sediments. The risk-management framework (Chapter 3) can be used at any of these sites. For some sites, interim decisions have been or will be made. Again, the committee emphasizes that even though decisions might have been made at a site and a remediation technology is being implemented, this framework will still provide a mechanism by which all affected parties can assess the effectiveness of the risk-management strategy and make any necessary modifications for improvement. Such corrections can range from redefining the risk-management goals to gathering more sediment or fish samples, to identifying new PCB sources, to assessing whether an experimental technology has field or commercial potential. The committee cautions that interim decisions should not be construed as a final solution for the site and stresses that the process must be iterative. Further evaluations and decisions by the affected parties will be required until the risk-management goals are met. The committee also recommends that before a management option is selected, a public comment period be allowed to provide an opportunity for those who may not have been involved in the framework process to express their concerns before a decision is made and a risk-management strategy implemented. FACILITATING THE PROCESS Decision-making with respect to PCB-contaminated sediments can be adversarial, in part because of the huge costs associated with many risk-man-
OCR for page 257
A Risk-Management Strategy for PCB-Contaminated Sediments agement strategies at contaminated sites (see Table 5–1a,b). This adversarial relationship is detrimental to the development of societally acceptable decisions, and conflict resolution must be an inherent part of any decision-making process. In the CERCLA process, this dissension can arise during preliminary discussions at a site to identify potentially responsible parties who might be at substantial financial risk. For example, EPA has recently estimated the costs to General Electric of dredging hot spots in the upper Hudson River to be approximately $490 million. Parties might take opposing views to allow themselves negotiating room. This process can result in lengthy and divisive negotiations by the affected parties. This protracted debate can cause the community to distrust both industry and regulatory agencies and regard the information that they provide as self-serving. The early establishment of partnerships among all parties, as discussed in Chapter 4, might circumvent or overcome the development of adversarial positions by some parties. Decision-making might require the use of an outside party, such as a facilitator, to help all the affected parties express themselves and understand the points of view and preferences of the others. Facilitators can be of use at any site, but they can be particularly valuable at sites where there is substantial distrust among affected parties and obstacles to the risk-management process appear to be intractable. The committee hopes, however, that all affected parties, including the regulatory agencies, will arrive at the decision-making stage with a willingness to listen to others, to consider their concerns, and to address their concerns as quickly as possible. The committee recognizes that, in general, the ultimate decision for managing a site resides with a federal or state regulatory agency, such as EPA. However, the committee emphasizes that these agencies do not operate in a vacuum and that they, the community, and the PRPs are subject to public scrutiny and societal and legislative pressures. In situations in which the affected parties feel that their concerns and needs have been acknowledged and addressed, the risk-management process can be more effective (see Box 8-2). CONCLUSIONS AND RECOMMENDATIONS To supplement the RI/FS process, the committee recommends that increased efforts be made to provide the affected parties with the same information that is to be used by the decision-makers in a form allowing for impartial and comprehensive review and evaluation. All affected parties must be involved in the data review and have an understanding of the regulatory constraints under which the decision-makers must operate. The affected parties must also have sufficient time to thoroughly review and comment upon the information.
OCR for page 258
A Risk-Management Strategy for PCB-Contaminated Sediments BOX 8–2 Waukegan Harbor Area of Concern Waukegan Harbor, located on the shore of Lake Michigan, was identified as polluted in 1972 (EPA 1997). PCBs were the primary pollutant of concern and had resulted in degradation of the benthos, restrictions on dredging activities, beach closing, degradation of plankton populations, and loss of fish and wildlife habitat. Fish consumption advisories had also been posted. A Citizens Advisory Group (CAG) was organized in 1990 with members from industry, fishing interests, environmental interests, and residents. The CAG assisted in obtaining cooperation from local interests on additional investigations, such as groundwater monitoring. The CAG was able to obtain access from business and federal grant money to install the monitoring wells. The CAG is also working with a local bank to resolve environmental concerns regarding a defunct salvage yard. In 1997, the fish consumption advisory was removed for Waukegan Harbor. Stage one of the remedial action plan was successfully completed in 1993, and subsequent risk-management efforts are still under way to address the other impairments. When considering the best ways to manage risk at a PCB-contaminated site, a broad variety of options should be considered individually and collectively (see Table 7–3). Focusing too early on possible remediation technologies to the exclusion other options and having particular preference for a single-faceted solution can curtail consideration of potentially viable options. The risks posed by PCB-contaminated sediments and management efforts extend beyond human health and ecological effects to economic, cultural, and societal impacts that must be factored into any risk-management strategy. The committee appreciates that it might be more difficult for the regulatory agencies to factor in risks other than human health or ecological impacts, let alone quantify them. At most sites, management goals focus on reducing risks to humans who may consume contaminated fish (see Table 5–1). The committee found that regulatory agencies do not give sufficient attention to other risks, including ecological effects, impacts on the local economy, or cultural traditions. Consequently, acceptance of the proposed risk-management strategy is often lacking among affected parties for whom those risks are major concerns. There is no preferred or default risk-management strategy for all PCB-contaminated sites. The optimal strategy for a particular site is dependent
OCR for page 259
A Risk-Management Strategy for PCB-Contaminated Sediments upon site-specific factors and risks and such conditions as sediment depth and composition, ecosystems, extent of contamination, and the presence of cocontaminants. The array of risks to be assessed are also site-specific and management-option-specific. When selecting a risk-management strategy for a site, decision-makers must be sensitive to affected parties’ views on the short-term and long-term risks, not only from the PCBs themselves but also from the implementation of any management option. Risk tradeoffs might be required to achieve the risk-management goals. REFERENCES Davies, J.C., 1995. Comparing Environmental Risks: Tools for Setting Government Priorities. Washington, DC: Resources for the Future. EPA (U.S. Environmental Protection Agency). 1991. Guidance on Oversight of Potentially Responsive Party Remedial Investigations and Feasibility Studies. Office of Solid Waste and Emergency Response (OSWER) Directive No. 9835.1(c). [Online]. Available: http://es.epa.gov/oeca/osre/910701-1.html. EPA (U.S. Environmental Protection Agency). 1997. Waukegan Harbor Area of Concern. Great Lakes Area of Concern. U.S. Environmental Protection Agency. [Online]. Available: http://ww.epa.gov/grtlakes/aoc/waukegan.html. [November 21, 1997]. Graham, J.D., and J.K.Hammitt. 1995. Refining the CRA Framework. Pp. 93–109 in: Comparing Environmental Risks: Tools for Setting Government Priorities, J.C.Davies, ed. Washington, DC: Resources for the Future. Graham, J.D., and J.B.Wiener, eds. 1995. Risk Versus Risk: Tradeoffs in Protecting Health and the Environment. Cambridge, MA: Harvard University Press. Muno, W. 1999. A Great Lakes Perspective of Sediment Contamination. U.S. EPA Region 5. Paper presented at Public Meeting Sections, University of Wisconsin at Green Bay, September 28, 1999. NRC (National Research Council). 1997. Contaminated Sediments in Ports and Waterways: Cleanup Strategies and Technologies. Washington, DC: National Academy Press. PCCRARM (Presidential/Congressional Commission on Risk Assessment and Risk Management). 1997. Framework for Environmental Health Risk Management. Final Report. Washington, DC: The Commission. Renholds, J. 1998. In Situ Treatment of Contaminated Sediments. Technology Innovation Office, Office of Solid Waste and Emergency Response, U.S. Environmental Protection Agency, Washington, D.C. December. [Online]. Available: www.epa.gov/swertio1/products/renhold.htm. TERA (Toxicology Excellence for Risk Assessment). 1999. Comparative Dietary Risk: Balancing the Risks and Benefits of Fish Consumption. Final Report. Toxicology Excellence for Risk Assessment, Cincinnati, OH. [Online]. Available: http://www.tera.org/pubs. August.
Representative terms from entire chapter: