Superfund and groundwater remediation: Another perspective
By William D.Rowe,Jr.
The commentary by Curtis Travis and Camlyn Doty on groundwater remediation at Superfund sites (ES&T, October 1990, p. 1464) emphasizes a proverb that is worth repeating: Don’t pollute groundwater resources because cootaminant plumes have no quick fix. This was underscored 10 years ago when earth scientists at the US.Geological Survey stated that “. . .deterioration in [groundwater] quality constitutes a permanent loss of water resource because treatment of the water or rehabilitation of the aquifers is presently generally impractical” and “solutions rest largely in changing 370 Environ. Sci. Technol., VoI. 25, NO.3,1991
[land- and water-management practices] to take into account the susceptibility of the groundwater resources to degradation” (2). Thanks in part to the US. Geological Survey, the above proverb comes as no big surprise. What does come as a surprise, however, is not so much Travis and Doty’s list of recommendations for modifying the Superfund approach to groundwater remediation, but the manner in which they are presented to the reader. These recommendations we presented as “next steps” for policy makers in Superfund. But io fact many of their recommendations have been under consideration by EPA and Superfund for some time. To
illustrate this point, the authors’ recommendations are f m t summarized below and then discussed individually in terms of existing or needed regulatory policy in Superfund. The authors make six recommendations. They are: (1) start groundwater actions early at sites: (2) make the remedial goal plume containment and contaminant mass reduction: (3) focus on source control actions at sites; (4) classify plumes on the basis of remediation priority by taking aquifer water quality and use into account; (5) admit up front that aquifer restoration is unachievable; and (6) abandon chemical-specific cleanup goals for remedial action.
0013-936w91/0925-370$02.50/0B 1991 American Chemical Society
Recommendations 1 through 3 can be found in Superfund policy or guidance. With regard to Recommendation I , for instance, EPA has stated in a directive that regional EPA offices “initiate response action early” at appropriate sites to prevent further migration of contaminants from sources (2). Recommendation 2 turns out to be a major finding and, in part. a recommendation of EPA’s 1989 groundwater extraction evaluation effort (3).Recommendation 3 was addressed in the Superfund Management Review, for example, “actions may be taken to prevent the spread of contamination, such as using caps, berms, and slurry walls” (4). This last statement addresses the primary importance of eliminating or minimizing the source term in the groundwater remediation strategy at a site. Recommendations 4 and 5 are not stated explicitly in Superfund policy statements per se, but are borne out in the descriptive text of groundwater Records of Decision (RODs) that support a range of selected remedial actions at sites. A review of the 271 groundwater RODs from fiscal year 1982 through the third quarter of fiscal year 1989 reveals that EPA has selected site-specific remedies that recognize the value of Recommendation 4 above, as well as the reality that complete restoration is either not possible or not necessary (5).Out of the 271 RODs, 77 (28%) called for complete aquifer restoration and 194 called for partial restoration. Of the 194 partial restoration RODs, 96 called solely for institutional controls and monitoring. Another 24 called for wellhead treatment. The remaining 74 partial restoration RODs called for a combination of leachate collection and treatment, containment, or groundwater pumping afid treatment. The range of selected remedial actions seems to indicate. then, that some plumes are worth active restoration efforts whereas others are not. Travis and Doty neglect to mention the full range of remedial actions EPA has selected over the years.
Recommendations 5 and 6, however, have not been incorporated into Superfund policy, and one should not anticipate that they will become policy. Reasons for this are readily apparent. Stating up front that aquifer restoration is unachievable at all sites sets the stage for making a “no action” or “limited action” decision when containment and partial restoration options may exist at some sites. Secondly, abandoning chemical-specific cleanup goals up front undermines regulatory control derived from using concentration limit goals as a baseline for evaluating the performance of remedial action at sites. As an alternative to these two recommendations, it is suggested that site-specific cleanup goals continue to be determined, if for no other reason than that they allow the regulator to delineate groundwater target areas for further management. This is consistent with other regulatory programs that require both detection and compliance monitoring at facilities in conjunction with the establishment of site-specific groundwater protection standards. Examples of other programs that require compliance with chemical-specific cleanup goals have been developed under the Resource Conservation and Recovery Act in 40 CFR Part 264, Subpart F, and the Uranium Mill Tailings Radiation Control Act in 40 CFR 192, Subparts A X and IO CFR 40,Appendix A. Rather than stating that acquifer restoration is unachievable across the board, such a determination should. as a matter of general policy, be made on the basis of site-specific efforts to remediate groundwater, or assessments which indicate that feasible solutions do not exist. As a result, there is regulatory pressure directed at finding innovative solutions to some of our problems-messes that need not be left to future generations. Secondly, performance evaluations will in actuality dictate the need for technical impracticability waivers to meeting cleanup goals. When technical impracticability is demonstrated, or contaminant levels in groundwater are as low as achievable considering the range of remedial actions, then waivers should be considered in accordance with section 121(d)(4)(c) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Likewise, if restoration to cleanup goals is not practicable, then under special circumstances, alternate concentration limits may be established on site in accordance with section 1 2 1 ( d ) ( 2 ) ( b ) ( i i ) of CERCLA. In either case, enforceable controls on the use of this water will be necessary. The realization that groundwater efforts will result in residual contamina-
tion problems at many Superfund sites in the future requires the development of technical guidance for the application of waivers and alternate concentration limits under CERCLA. In the past, an effective mechanism for the application and approval of waivers and alternate concentration limits has been lacking. Such a mechanism should be established which assures that the granting of waivers and alternate concentration limits is coupled with a list of alternate actions that ensure the protection of human health and the environment. As stated above, groundwater contamination at many sites has no quick fix and usually constitutes a permanent loss in water resource. Travis and Doty have made some good recommendations and it is obvious that EPA has recognized the value of many of them. What remains ahead for EPA is a difficult task of dealing with residual groundwater contamination. In spite of many active restoration efforts, residual contamination will persist at many sites, requiring a management strategy that balances active restoration, waivers, alternate concentration limits, and source control efforts. Where contamination is not a problem, the proverb is a familiar oneprevention.
References (I)
Meyer. G. “Ground-Water Contamination-No ‘Quick Fix’ in Sight”: reprint from USCS Yeorhoot US. Geological Survey: Washington, DC. 1980. (2) “Considerations in Ground Water Remediation at Superfund Sites”; Office of Solid Waste and Emergency Response. U.S. Environmenral Prot&oh Agency: Washington, E€. October 18. 19x9 Directive No. 9355.4-03. (3) “Evaluation of Ground Water Extraction Remedies”: Office of Solid Waste and Emergency Response. US. Environmental Protection Agency: Washington. DC. 1989 EPN540/2-89/054, (4) “A Management Review ofthe Superfund Program”: US. Environmental Protection Agency: Washington. DC. May 1989. ( 5 ) “Superfund Records of Decision Update”: Office of Solid Waste and Emergency Response. US. Environmental Pmtection Agency: Washington. DC. January 1990 Publication 92CQ.S-2161.
William D . Rowe, Jr., is a member of the technical staff in the Energy, Resource and Environmental Sysrems Division of The MITRE Corporation. He is a geologist and received his Ph.D. from the University of Texas ar Da//as. He has worked in EPA Region 6 as a remedial projecr manager ( I 988-present) and at USGS as a physical scientisr (I9 8 N 9 8 8 ) . Environ. Sci. Technol.. Vol. 25, NO.3, 1991 371
