The Department of Energy (DOE) Office of Environmental Management’s (EM’s) mission is the safe cleanup of sites associated with the government-led development of nuclear weapons and nuclear energy. Although many of these legacy sites have completed cleanup, the largest and most complex sites have not been fully remediated. The cleanup of EM’s sites is proceeding under legally enforceable agreements with timelines for hundreds of milestones. EM is reviewing alternative approaches to increase effectiveness and improve cost-efficiencies of its cleanup activities, especially for sites that will have residual contamination when active cleanup is complete. To inform this review, EM asked the National Research Council (NRC) to convene two workshops to examine best practices for risk-informed remedy selection, closure, and post-closure control of radioactive and chemically contaminated sites that cannot be remediated for unrestricted release (see Appendix A for the statement of task).
The two workshops were organized by a four-member planning committee with extensive expertise in contaminated site cleanup and environmental decision-making practices. Biographical sketches of the committee members and staff are provided in Appendix B. The workshops brought together federal and state agency decision makers responsible for contaminated site cleanup and closure decisions, federal and state regulators, key stakeholders, and other technical experts to explore topics contained in the statement of task through presentations, case studies, and discussions.
The first workshop was held on October 30-31, 2013. It focused on examining holistic approaches for remediating sites with multiple contaminant sources and post-closure uses, and approaches for incorporating
a sustainability framework into decision making regarding site remediation, closure, and post-closure control (bullets 1 and 4 of the statement of task; see Appendix A). The agenda for Workshop 1 can be found in Appendix C.1 The workshop summary is Volume I of this report.
The second workshop was held on January 9-10, 2014. It focused on post-closure controls, assessment of long-term performance of site remedies (bullets 2 and 3 of the statement of task; see Appendix A), and best practices for risk-based remediation decisions. The agenda for Workshop 2 can be found in Appendix E.2 The workshop summary is Volume II of this report. The workshop summaries were authored by different rapporteurs so there are stylistic differences between them.
The workshop summaries provide factual descriptions of the workshop presentations and discussions. They do not contain consensus findings and recommendations. Several major themes and debated topics emerged from the workshops and are described below.
Remediation decisions for DOE’s contaminated sites can involve complex technical issues, cost millions or even billions of dollars, and be impactful to human health and the environment. Various tools and approaches have been developed to guide remediation decisions in an effective, efficient, and transparent manner.
Several tools and approaches were discussed at the workshops including risk assessments, decision analysis, and sustainability frameworks. Risk assessments traditionally account for technical components of risk (e.g., calculating risk of exposure of radioactive or chemical contaminants) (see Volume I, Chapter 2 [Vol. I, Ch. 2] and Volume II, Section 2.8 [Vol. II, Sec. 2.8]). Workshop 1 participants discussed other aspects of risk including scheduling and external risks (see Vol. I, Ch. 2 and Sec. 3.5). Decision analysis tools can be used to quantify the many components that contribute to risk management decisions for a complex problem such as cleanup technologies, contamination levels, remedy costs, and societal preferences for the use of the site. The components are individually characterized (e.g., in the case of multi-attribute utility analysis by utility functions) and then combined. The results provide insight into how multiple components combine to affect final outcomes (e.g., reduction in risk, access to the site in least amount of time, or determination of costs of remedies) which can be used to make decisions (see Vol. II, Sec. 2.8). Sustainability frameworks
1 Presentations from Workshop 1 can be found at: http://sites.nationalacademies.org/PGA/sustainability/PGA_085849.
2 Presentations from Workshop 2 can be found at: http://dels.nas.edu/Past-Events/Best-Practices-Risk-Informed-Remedy/AUTO-8-12-72-G?bname=nrsb.
(see Vol. I, Sec. 1.6 and Vol. II, Sec 2.4) describe how to integrate sustainability principles3 into a decision-making process. This process allows the environmental, societal, and economic issues to be communicated among the stakeholders and can result in decisions with broader consensus and longevity.
Workshop 1 introduced the concept of the use of sustainability frameworks to guide remediation decisions and provided several case studies (see Vol. I, Sec. 4.1). Workshop 2 discussed the importance of balancing and optimizing the environmental, societal, and economic pillars of complex, contaminated sites and also provided several case studies (see Vol. II, Sec. 2.4 and 3.5). It was recognized that within the sustainability framework approach a win-win-win solution is rarely available. Rather, a balancing between the environmental, societal, and economic issues is a more likely outcome—sometimes requiring lengthy discussions and negotiations among stakeholders (see Vol. II, Sec. 5.1 and Ch. 6).
REGULATIONS AND FLEXIBILITY
Workshop participants discussed the flexibility of laws and regulations that govern environmental cleanup decisions. The following laws were specifically discussed:
- National Environmental Policy Act (NEPA) was highlighted as containing language compatible with sustainability principles, “to create and maintain conditions, under which humans and nature can exist in productive harmony, that permit fulfilling the social, economic, and other requirements of present and future generations” (NEPA ; EO 13514 ; see Vol. I, Sec. 1.6). Some workshop participants recognized that the NEPA process included sustainability principles from its inception (although at the time of NEPA’s enactment the term “sustainability” was not widely adopted) (see Vol. II, Sec. 2.4).
- Resource Conservation and Recovery Act (RCRA) (see Vol. I, Sec. 1.2) was discussed at both workshops. Many participants noted that RCRA imposes prescriptive standards-based approaches for remedies and therefore is least favorable toward the incorpo-
3 Sustainability principles and sustainability frameworks are discussed in Vol. I, Sec. 1.6. Sustainability principles guides an agency’s implementation of regulatory mandates and discretionary programs in ways that optimize benefits as they relate to the social, environmental, and economic pillars. Sustainability frameworks provide an analytical process for decision making related to linkages of sustainability principles across all federal agencies. A framework is divided into four distinct phases: (1) preparation and planning; (2) design and implementation; (3) evaluation and adaptation; and (4) long-term outcomes.
ration of sustainability principles as compared to the other laws discussed (see Vol. II, Sec. 4.5).
- Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) (see Vol. I, Sec. 1.2) was discussed widely at both workshops. Workshop 1 focused on whether CERCLA allowed for the flexibility to include sustainability considerations into its remedies. Some participants proposed adding a “tenth criterion”4 to CERCLA to define the incorporation of sustainability principles into the law (see Vol. I, Ch. 2). Discussions during Workshop 2 highlighted CERCLA’s inherent flexibility and its demonstrated ability to accommodate sustainability principles within the existing nine criteria for remedy selection (see Vol. II, Box 2.2 and Sec. 2.6 and 4.5).
Workshop 1 focused on the flexibility to make remediation decisions within existing regulations; Workshop 2 considered how existing regulations based on the laws identified above may need to be “reset” or updated to account for the complexities of the contaminated sites that have yet to be fully remediated. Discussions included how updating of regulations could account for the knowledge gained from three decades of site remediation work (see Vol. II, Sec. 2.8, 3.3, and 4.1).
MODELS AND TIMEFRAMES
The usefulness of conceptual site models to communicate with the public and guide decisions was raised at both workshops (see Vol. I, Sec. 3.1, and Vol. II, Sec. 2.8 and 5.1). The importance of models based on realistic physical processes, as opposed to conservative estimates of the physical processes, was highlighted in Workshop 2 (see Vol. II, Sec. 2.3 and 5.1).
Long-term assessments that use models which utilize realistic timeframes were discussed. For example, limiting model predictions to timeframes of hundreds—instead of millions—of years was discussed in Workshop 2 (see Vol. II, Sec. 2.3 and 5.1).
The sequencing of remediation activities within the decision-making process was introduced in Workshop 1 (see Vol. I, Ch. 2). Sustainability frameworks may offer a way to incorporate sequencing into the existing remedy selection process to guide decisions as discussed in Workshop 2 (see Vol. II, Sec. 5.1).
4 CERCLA has nine criteria; descriptions of these criteria can be found in Vol. II, Box 2.2.
COMMUNICATION AMONG STAKEHOLDERS
Communication among stakeholders throughout the decision-making process was discussed in both workshops. Workshop 1 participants explained how communication enables flexibility in regulations (e.g., the frequent and occasionally lengthy discussions among stakeholders mentioned previously; also see Vol. I, Ch. 2). Several participants in Workshop 2 stressed the importance of communication with local stakeholders (e.g., tribal nations) early and often in the decision-making process (see Vol. II, Sec. 3.1). Tools developed to support decision making can provide transparency and improve communications if used properly (e.g., decision analysis tools; see Vol. II, Sec. 2.8).
WEIGHING ENVIRONMENTAL RESOURCES IN DECISIONS
There was debate on how to appropriately weigh environmental concerns in a sustainability-based decision-making process. Specifically, participants discussed how to represent environmental concerns within a sustainability framework when the societal and economic pillars may have stronger interests and advocates (Vol. I, Ch. 4 and Vol. II, Sec. 3.6).