|From:||Lenny Siegel <email@example.com>|
|Date:||16 Dec 1998 13:36:49|
|Subject:||NRC Reviews Navy Cleanup|
The National Research Council, the policy arm of the National Academy of Sciences, has just published a review of risk-based remediation as it applies to U.S. Navy cleanup projects. I was a member of the committee that prepared the report. Below is an official summary of the report's key findings and recommendations. Environmental Cleanup at Navy Facilities: Risk-Based Methods By Laura Ehlers The Environmental Restoration Program of the United States Navy is responsible for 4,448 waste sites at Navy installations across the country. At almost every Navy base, soils, sediment, or ground water have been exposed to chemical contaminants, such as metals, chlorinated solvents, and petroleum compounds. Because cleanup efforts can be time consuming, expensive, and of limited effectiveness, the Navy requested that the National Research Council (NRC) study how the Navy can improve its Environmental Restoration Program. A new report from the WSTB, Environmental Cleanup at Navy Facilities: Risk-Based Methods, present the results of the first phase of the study, focusing on the use of risk-based methodologies for increasing the speed and cost-effectiveness of Navy environmental remediation projects. The report was written by the WSTB Committee on Environmental Remediation at Naval Facilities, chaired by Edward Bouwer of the Johns Hopkins University. The report reviews several risk-based methodologies, giving detailed consideration to the EPA's Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the American Society for Testing and Material's (ASTM) Risk-Based Corrective Action (RBCA) methodology. The CERCLA process, which governs cleanup of hazardous wastes at 66 percent of all Navy sites, outlines specific risk assessment and risk management actions that should be taken from site discovery to ultimate site closure. The ASTM RBCA methodology (which is a voluntary set of practices) does the same for (1) leaking petroleum underground storage tanks (called petroleum RBCA in the report) and (2) waste sites containing chemicals other than petroleum (called chemical RBCA in the report). The CERCLA and RBCA processes are remarkably similar. Both advocate the use of risk assessment to determine the inherent level of risk posed by a contaminated site and to set goals for cleanup. The mathematical equations suggested by each process are the same, and they rely on equivalent acceptable risk levels. Both methodologies outline important (and similar) criteria that must be taken into account when selecting the remedial option. However, the ASTM RBCA methodology is more systematic than the CERCLA process because it uses a common framework -- a tiered approach -- for all types of contamination. Under RBCA's tiered approach, site conditions are compared to either generic or site-specific cleanup levels and, depending on the results, the site may be closed, cleaned up, or further characterized and analyzed. Whether the CERCLA process uses a tiered approach depends on (1) the type of contamination, (2) the types of contaminated media, and (3) the presence of generic screening levels and other legal requirements in individual states. Another important difference between the two methodologies is that CERCLA has a preference for source removal, while the RBCA approach gives equal consideration to source removal (also referred to as treatment), engineering controls such as containment, and institutional controls. These differences have led to a general perception that ASTM's RBCA process is faster and less costly than the CERCLA process but is more likely to result in remedies that leave contamination in place. The greater potential for risk-based methods to result in remedies that leave contamination in place is a significant weakness of these methods compared to source removal. Leaving contamination in place creates uncertainties in the remedial option that must be considered prior to implementing a risk-based approach. The report describes these various uncertainties and recommends how to assess and reduce uncertainties associated with both risk assessment and risk management. The report identifies eleven criteria that should be part of any risk-based methodology adopted by the Navy. The committee that wrote the report developed these criteria after considering existing methodologies and the unique environmental conditions present at Navy facilities. Such unique conditions include (1) extremely high levels of contamination at some sites, (2) chemical mixtures with unknown constituents, (3) a wide variety of human and ecological receptors (due to facility proximity to coastal areas), (4) a wide range of activities that generate waste, and (5) the rushed time line on which many Navy facilities are expected to close (and thus have approved cleanup activities under way). 1. A risk-based methodology adopted by the Navy should facilitate prioritization of contaminated sites at individual installations. 2. It should provide a mechanism for increasing the complexity of the remedial investigation when appropriate. 3. It should provide guidance on data collection needed to support the development of site-specific cleanup goals. 4. It should provide for integrated assessment of sites affecting the same human or ecological receptors. 5. It should encourage early action at sites (1) where the risk to human health and the environment is imminent and (2) for which the risks are demonstrably low and remediation is likely to be more rapid and inexpensive. 6. It should consider relevant uncertainties. 7. It should provide a mechanism for integrating the selection of the remedial option with the establishment of remedial goals. It should also provide quantitative tools for developing risk management strategies. 8. It should have options to revisit sites over the long term. 9. It should be implemented in a public setting with all stakeholders involved. 10. Its guidance document should undergo both external, independent scientific peer review and public review. 11. It must comply with relevant state and federal statutory programs for environmental cleanup. The report recommends that the Navy develop a risk-based methodology that embraces each of these eleven criteria. These criteria are important for overcoming many of the weaknesses associated with the risk-based methodologies that were evaluated in the report. In particular, if a risk-based methodology gives sufficient attention to long-term risks (Criterion 8), remedies in which contamination remains on site become less problematic. Public trust in such a risk-based approach is likely to be greater if the responsible party continues to be involved via long-term monitoring and enforcement of institutional controls. The report concludes that the ASTM RBCA methodology, which the Navy specifically requested be evaluated, fully satisfies only five of these eleven criteria. Thus, the report does not recommend the adoption of the ASTM RBCA methodology at Navy facilities unless it is modified to satisfy all eleven criteria. The report also states that the "perceived time and cost savings associated with the use of ASTM RBCA at petroleum underground storage tanks are less likely to accrue to the Navy because of the complexity of its hazardous waste sites." ASTM RBCA is identified as a possible starting point for constructing a Navy-specific risk-based framework, but this is not a requirement. The report closes with final thoughts about measuring success in the Navy Environmental Restoration Program. Funding was provided by the U.S. Navy. To order a prepublication copy of the report, contact the National Academy Press at (800) 624-6242 or http://www.nap.edu. Lenny Siegel Director, Center for Public Environmental Oversight c/o PSC, 222B View St., Mountain View, CA 94041 Voice: 650/961-8918 or 650/969-1545 Fax: 650/968-1126 firstname.lastname@example.org http://www.cpeo.org
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