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7 Better Decision Making During the Long-Term Management of Complex Groundwater Contamination Sites
Pages 261-284

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From page 261...
... Furthermore, no transformational remedial technology or combination of technologies appears capable of overcoming the inherent technical challenges to restoration at these complex sites. Rather, the nation's cleanup programs are transitioning from remedy selection into remedy operation and long-term management (LTM)
From page 262...
... SETTING THE STAGE All complex contaminated groundwater sites will ultimately transition from investigation, through remedy selection, implementation, and operations, to long-term management and ultimately (without any time frame constraint) to attainment of unlimited use and unrestricted exposure goals.
From page 263...
... There are uncertainties and subjectivity in selecting the appropriate technologies for site characterization and remediation, including differing perspectives over the intensity of data collection and its timing and cost effectiveness. Second, there can be disagreements among potentially responsible parties, the states and even within the ten EPA Regional offices over the appropriate risk management approach to take at an individual site (i.e., how much aggressive source removal is warranted when considering the time to reach groundwater cleanup goals and the high costs of such actions)
From page 264...
... . While its groundwater restoration Road Map focuses on CERCLA, EPA has stated elsewhere that the methodology also applies to groundwater remediation under the RCRA Corrective Action program (see Chapter 3)
From page 265...
... In the opinion of the Committee, lack of guidance on this transition is unfortunate given the likelihood that many contaminated groundwater sites pose technical challenges that will not allow for achievement of unlimited use and unrestricted exposure throughout the entire contaminated aquifer for many decades.
From page 266...
... Initial Steps of the Alternative Decision Process Figure 7-2 includes the processes currently followed at all sites regulated under CERCLA and at many complex sites regulated under other federal or state programs (RCRA Corrective Action or state Superfund sites) , but it provides more detailed guidance for sites where recalcitrant contamination remains in place at levels above those allowing for unlimited use and unrestricted exposure.
From page 267...
... FIGURE 7-2  Key decisions for complex sites with groundwater contamination. Figure 7-2
From page 268...
... The MEW Superfund facility in Mountain View, California, is an example of a site that was considered "protective" through one five-year review cycle until 2009, when the remedy was no longer considered protective because of newly identified human health risks from vapor intrusion. Similar cases may arise elsewhere as the potential risks from vapor intrusion become better understood.
From page 269...
... Thus, the asymptote analysis is not just a valuable decision-making tool, it is also a vital part of communicating the challenge of groundwater remediation to the public. The paradigm embodied in Figure 7-2 strikes a balance between deciding not to undertake any risk reduction efforts as part of the original remedy because of the impracticability of attaining drinking water standards
From page 270...
... . For each of the possible alternatives, the transition assessment considers the nine remedy selection criteria of CERCLA or similar criteria established under other regulatory regimes, particularly the risk of any residual contamination expected to remain in aquifers that are not likely to be restored; costs such as life-cycle costs and the marginal costs of remediation compared to the level of risk reduction achieved; and state and community acceptance.
From page 271...
... In cases where the site does not have a legal release, one question to be asked is, "is a new remedy warranted based on the original CERCLA or State remedy selection criteria? " The answer to this question could be "yes" if a new technology has been recently developed that could address the contamination more effectively (i.e., significantly reduces the timeframe to achieve restoration compared to the remedies considered during the initial feasibility study)
From page 272...
... . A focused feasibility study was recently conducted to compare alternative remedies, including combinations of enhanced groundwater extraction, additional use of in situ oxidation technologies, enhanced bioremediation, and land use controls, among oth
From page 273...
... The current status of the site following completion of the focused feasibility study appears to be preparation of an interim ROD, which will require implementation of an in situ bioremediation remedy to achieve revised remedial action objectives for the site. The path to a final ROD is uncertain at this time (Laurie Haines-Eklund, AEC, personal communication, 2012)
From page 274...
... First, existing costs represent a sunk investment and the relevant questions deal with the best path forward from the current point in time. Second, initial remedy selection is based on projected risk reductions and projected costs, both of which could be wrong.
From page 275...
... on lack of protectiveness, the risk analyses that occur during a typical five-year review provide an incomplete understanding of risks posed at a site presently and in the future. A transition assessment would instead include more comprehensive risk assessment, including • Better understanding of risk reductions as predicted in the ROD compared with actual risks reduced from ongoing remedial activi ties.
From page 276...
... Indeed, although the five-year review is shown as a single box in Figure 7-2, it would occur at regular intervals at all sites with residual contamination, under either active or passive long-term management. Thus, the questions posed in Figure 7-2, including those in the transition assessment, could theoretically all occur under the umbrella of an improved five-review process.
From page 277...
... , the transition assessment should apply to RCRA sites undergoing corrective action for groundwater cleanup and other cleanup sites. However, the RCRA corrective action program is implemented through corrective action permits while a facility is still in operation.
From page 278...
... A transition assessment is not necessary at sites where the remedy is likely to attain drinking water standards within a reasonable period of time. THE ROLE OF COMMUNITY INVOLVEMENT IN TRANSITION ASSESSMENT AND LONG-TERM MANAGEMENT At complex groundwater sites that are the focus of Figure 7-2 where achievement of long-term remedial objectives is difficult, complex community engagement strategies are essential because the potential risk from the contaminated groundwater is likely to persist for decades and in some cases many human generations.
From page 279...
... The Defense Department currently sponsors 265 Restoration Advisory Boards at active, closed, and former installations, while DOE hosts local boards at eight major cleanup sites (DoD, 2011; DOE, 2011)
From page 280...
... The local Community Advisory Board developed a list of remedial priorities and offered its own screening of remedial technologies, and EPA has incorporated the community's ideas into its study. One of the reasons that community involvement was sustained long after the 1998 installation of the regional groundwater remedy is that other issues became pressing, such as wetlands cleanup, the emergence of vapor intrusion from the regional plume into an adjacent residential area, and the preservation of historic Hangar One at Moffett Field.
From page 281...
... If the effectiveness of site remediation reaches a point of diminishing returns prior to reaching cleanup goals and optimization has been exhausted, the transition to MNA or some other active or passive management should be considered using a formal evaluation. This transition assessment, which is akin to a focused feasibility study, would determine whether a new remedy is warranted at the site or whether long-term management is appropriate (see Figure 7-2)
From page 282...
... Also as part of the transition assessment, formal post-remedy risk assessment should be conducted to compare alternatives, including long-term active or passive management. This risk analysis should explicitly consider uncertainty and take into account both individual and population risks, where appropriate, such that the relative risk reduction of the alternatives can be determined.
From page 283...
... 2011b. Groundwater Road Map Recommended Process for Restoring Contaminated Groundwater at Superfund Sites.
From page 284...
... 2011e. Memorandum from Mathy Stanislaus, Assistant Administrator for Solid Waste and Emergency Response to Carolyn Copper, Director for Program Evaluation, EPA Office of Inspector General, Re: Response to the Office of Inspector General Final Evalu ation Report, "Stronger Management Controls Will Improve EPA Five Year Reviews of Superfund Sites (Report No.


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