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National Academy of Sciences Group Recommending Methods to Facilitate Transition of Cleanup Programs from Problem Identification and Remedy Selection to Long-term Management

November 8, 0012

The National Research Council, an arm of the National Academy of Sciences (NAS), today released a report, “Alternatives for Managing the Nation’s Complex Contaminated Groundwater Sites” (available from the National Academies Press at or from, summarizing the state of the practicality of the cleanup of contaminated groundwater at complex sites and recommending significant changes to the current approaches for such sites. The author of this Alert was a member of the NAS committee that wrote this report.

The report estimates that nationwide there are more than 126,000 hazardous waste sites that are still in the process of being cleaned up and have not yet been removed from existing federal, state and other priority lists. The lower- and upper-end estimate of the cost to complete remediation of these sites are $110 billion and $127 billion, respectively. The report states that these estimated costs are likely to be an underestimate of future liabilities. An undetermined, but larger, number of sites have reduced the residual levels of chemicals in groundwater, but have not yet attained levels that allow for unlimited use/unrestricted exposure (the goal of most groundwater cleanup programs).

The report concluded that it is not practical to attain groundwater cleanup goals (typically the drinking water standard) within 50-100 years at complex groundwater contamination sites (estimated to be more than 12,000 sites) and no new technologies are on the horizon. At these complex sites, residual contamination will remain in place at levels that do not allow for unlimited use and unrestricted exposure over the long term, requiring site management to ensure protectiveness. This conclusion is consistent with the conclusions of other NAS committees since 1994, but this is the first NAS report to focus on issues raised by the transition of the nation’s cleanup programs from problem identification and remedy selection to remedy implementation and long-term management.

Specifically, the report concludes that when the effectiveness of site remediation reaches a point of diminishing returns (e.g., the annual reduction in concentration levels off, but the costs remain significant) prior to reaching groundwater cleanup goals, the site should be transitioned to monitored natural attenuation (MNA) or other passive or active long-term management, based on a formal, transparent evaluation. The evaluation (called a “transition assessment”) would be akin to a focused feasibility study and would be subject to public comment. The transition assessment determines whether a new remedy is warranted at the site (at least where there is no legal release of liability) or which type of long-term management is appropriate. For example, no new remedy can be mandated where a judicially enforceable consent decree provides a legal release of liability as long as the remedy in the consent decree is implemented and the remedy remains protective of human health and the environment. A potentially responsible party (PRP) subject to a consent decree, however, may propose to modify a consent decree to perform a new remedy (regardless of the legal release), particularly if the long-term costs of the new remedy is less than the consent decree remedy or if the company believes implementing additional cleanup is consistent with internal company sustainability policies.1

Thus, the cleanup paradigm recommended by the committee is to reduce the inherent risk from exposure to contaminated groundwater and attain the unlimited use and unrestricted exposure levels where practical. As a result, the focus of the remediation resources will be on the management of the site to ensure protectiveness for as long as it is necessary (which may be a very long time).

In this author’s view, this approach (for the first time) recognizes the consequence of the repeated findings of groundwater cleanup experts that, in the source zone of complex groundwater sites, no existing or reasonably anticipated remedy can achieve groundwater cleanup goals (generally drinking water standards). Requiring an additional remedy that, when implemented, still will not attain groundwater cleanup goals simply does not provide any meaningful benefit. The presence of emerging contaminants and lowering of drinking water standards just make the attainment of unlimited use and unrestricted exposure levels (generally the goal of federal and state programs) all the more unachievable. Thus, thousands of groundwater contamination sites will require institutional controls and other management for many decades, which is where the finite resources should be focused.

The report also summarizes the efforts to develop and implement “sustainable” remedy selection factors (i.e., not just environmental factors, but social and broader economic factors). The report concludes that the regulatory agencies and the Department of Defense should adopt new guidance detailing how to consider sustainability in the remedy selection process, to the extent supported by existing law (e.g., currently no federal cleanup statute includes sustainable cleanup factors).

Additionally, the report:

  • recommends increasing the role of risk assessment in the remedy selection process (e.g., taking into account that risk reduces as the remedy is implemented), the use of greater flexibility in remedy selection, and a careful consideration of the potential risk from vapor intrusion at all sites
  • concludes that public involvement should be improved in remedy selection, during five-year reviews, and during the proposed transition assessment
  • concludes that the EPA’s technical guidance for five-year reviews should be updated to provide a uniform protocol for analyzing the data collected during the reviews and reporting their results
  • describes the current effectiveness of remediation technologies and recommends additional research on promising technologies
  • describes generally the implications of leaving contamination in place and recommends the creation of national databases on institutional controls to track the effectiveness of long-term management.

The NAS report recommends that funding for long-term management be provided. However, the NAS report does not address innovative approaches to paying for the long-term management. The author of this article and two other members of the NAS committee on their own have discussed the idea of also transferring operational responsibility and future legal liability once sites have been transferred to a “long-term management-only organization” (LTMOO) in exchange for a payment of the net present value of the cost of long-term management. Thus, the PRPs would still pay for the remedy selected, its implementation and the long-term care. But the entity performing the work (i.e., the LTMOO) would have the expertise, experience, and funds to implement long-term care at specific sites and spread the site-specific risks over a large number of sites operated by the LTMOO.


1 In this context, new remedies involve new construction and different operating costs, so the author anticipates that it would be rare that a PRP would propose a new remedy and the regulator would oppose.

The material in this publication was created as of the date set forth above and is based on laws, court decisions, administrative rulings and congressional materials that existed at that time, and should not be construed as legal advice or legal opinions on specific facts. The information in this publication is not intended to create, and the transmission and receipt of it does not constitute, a lawyer-client relationship.

This article was originally published as a Pepper Hamilton LLP client alert.

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