NRC Reviews Navy Cleanup

[Lenny Siegel <lsiegel@cpeo.org>]

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
lsiegel@cpeo.org
http://www.cpeo.org