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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants 2 The Changing Regulatory Environment The driver for the Department of Energy's (DOE's) groundwater and soil cleanup technology development program is the need to meet applicable federal and state regulations for the cleanup of contaminated sites. DOE will not be able to meet all of the applicable regulations with existing remediation technologies and therefore must develop new technologies, as discussed in Chapter 1. An understanding of the cleanup goals required under existing regulations is thus critical to the administration of the Subsurface Contaminants Focus Area (SCFA) because the technologies developed by SCFA will have to be capable of meeting applicable regulatory requirements. Historically, regulators have used drinking water standards as baseline cleanup goals for contaminated groundwater. For soil, commonly regulators have set cleanup goals designed to protect the groundwater beneath the soil and to prevent exposure to contamination via soil ingestion or inhalation. However, these policies are changing rapidly. New policies for groundwater and soil cleanup will affect the range of remediation technology options that DOE can consider using at its sites and will therefore influence SCFA's priorities for technology development. This chapter first describes regulations that prescribe how groundwater and soil are to be cleaned up at DOE installations. It then reviews baseline cleanup goals for groundwater and soil contaminants under these regulations and describes in detail new policies that allow alterations to the historical cleanup process.
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants OVERVIEW OF APPLICABLE FEDERAL REGULATIONS During most of the period of nuclear weapons production, operations at DOE installations were managed under a veil of secrecy. DOE remained exempt from federal, state, and local solid and hazardous waste laws that were developed and applied to private industries. The initial spur for DOE to act on its legacy of environmental contamination came largely from two successful lawsuits against the agency, one filed by the Legal Environmental Assistance Foundation and decided in 1984, and another filed by the Natural Resources Defense Council and decided in 1989 (Probst and McGovern, 1998). These suits required DOE to comply with requirements of the Resource Conservation and Recovery Act, which governs management of contaminants from active waste treatment, storage, or disposal facilities. However, DOE remained exempt from other solid and hazardous waste laws until 1992, when Congress passed the Federal Facilities Compliance Act. Cleanup of DOE's installations is therefore still a relatively new undertaking. Table 2-1 lists laws applicable to the cleanup of groundwater and soil contamination at DOE installations. The listing is in order of significance to DOE remediation projects, rather than in chronological order. The Federal Facilities Compliance Act, listed first in Table 2-1, is the key law underlying all DOE cleanups because, as mentioned above, it established for the first time that DOE must comply with existing environmental statutes. The act makes federally owned and operated facilities subject to state-imposed fines and penalties for violation of hazardous waste requirements. It authorizes environmental regulators to treat DOE facilities like privately owned industrial facilities and to subject them to the same rules and liabilities. For cleanup of contaminated groundwater and soil at DOE installations, the most important laws are the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), listed second and third in Table 2-1. RCRA, enacted in 1976 and significantly amended in 1984, addresses the treatment, storage, and disposal of hazardous waste at operating facilities. The 1984 amendments brought "solid waste management units," which are currently inactive but formerly used hazardous waste disposal sites within the boundary of an operating facility, under the umbrella of RCRA, as well. CERCLA, enacted in 1980 and amended in 1986, governs the cleanup of groundwater and soil at inactive facilities. Most DOE installations are currently regulated under CERCLA, RCRA, or both (see Table 2-2). Individual
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants Table 2-1 Federal Regulations Applicable to DOE Remediation Projects Federal Law (year) General Description Significance to DOE Remediation Federal Facilities Compliance Act (1992) Establishes a definition of ''mixed waste'' and requires development of plans for its management. Waives the DOE (and other federal facilities') immunity from EPA and state hazardous waste regulations and sanctions. Establishes that DOE facilities are subject to and liable under federal and state waste management regulations, including CERCLA and RCRA. Resource Conservation and Recovery Act (1976); Hazardous and Solid Waste Amendments (1984) Establishes regulations controlling generation, transportation, treatment, storage, and disposal of hazardous materials for active industrial facilities. Contains requirements for groundwater monitoring. If groundwater contamination is identified, the RCRA corrective action process is implemented. Comprehensive Environmental Response, Compensation, and Liability Act (1980); Superfund Amendment and Reauthorization Act (1986) Establishes regulations for cleanup of inactive hazardous waste sites and determines the distribution of cleanup costs among the parties that generated and handled the hazardous substances disposed at these sites. Requires cleanup of inactive facilities and establishes procedures and requirements for site characterization and remedy selection. SARA provides additional requirements for documentation and distribution of information on releases of pollutants from facilities. Uranium Mill Tailings Remediation Control Act (1978), and amendments Establishes two programs to protect public health and the environment from exposure to contaminants from uranium mill tailings piles: one program addresses inactive sites; the other addresses active sites that are licensed by the Nuclear Regulatory Commission. Requires that DOE take charge of cleaning up contaminated groundwater and soil at 24 inactive uranium mining and processing sites.
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants Federal Law (year) General Description Significance to DOE Remediation Safe Drinking Water Act (1974) Develops drinking water standards that govern the quality of water delivered to the consumer and establishes the underground injection control program, which classifies and regulates types of injection well practices. If groundwater beneath a DOE facility can be used as drinking water, then cleanup levels must satisfy MCLs for chemicals regulated under the SDWA. Clean Water Act (1972), and amendments Establishes requirements controlling discharge of pollutants to surface waters. If groundwater beneath a DOE facility discharges to surface water bodies, then the CWA may be used to establish cleanup levels. Toxic Substances Control Act (1976), and amendments Establishes responsibility of manufacturers to provide data on health and environmental effects of chemical substances and provides EPA with authority to regulate manufacture, use, distribution, and disposal of chemical substances. Includes special management provisions for handling and cleaning up material containing PCBs, which are present in environmental media at DOE facilities. NOTE: CWA=Clean Water Act; EPA = Environmental Protection Agency; MCL = maximum contaminant level; PCB = polychlorinated biphenyl; SARA = Superfund Amendment and Reauthorization Act; SDWA = Safe Drinking Water Act
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants Table 2-2 Primary Regulatory Drivers for Groundwater and Soil Remediation at Select DOE Installations Primary Regulatory Driver Installation CERCLA RCRA Fernald x Hanford x x Idaho National Engineering and Environmental Laboratory x x Lawrence Livermore National Laboratory x Los Alamos National Laboratory x Mound Plant x x Nevada Test Site x Oak Ridge Reservation x x Paducah Gaseous Diffusion Plant x x Pantex Plant x x Rocky Flats Plant x x Sandia National Laboratories x Savannah River Site x x SOURCE: DOE. 1998. Remediation Action Program Information Center (RAPIC). Oak Ridge, Tenn.: Oak Ridge National Laboratory, RAPIC (http://www.em/doe.gov/rapic). cleanup sites may be regulated under both programs in situations where cleanup began under RCRA but where the installation was later listed on the National Priorities List (GAO, 1994). In other cases, RCRA cleanup sites may be very near, even next to, sites where cleanup is occurring under CERCLA (GAO, 1994). For example, at Hanford, the B-pond disposal site for liquid wastes is being cleaned up under RCRA, while abandoned trenches that once carried wastes to the pond are being cleaned up under CERCLA (GAO, 1994). RCRA established a manifest program to track hazardous waste at active facilities from the point of generation through transport to treatment, storage, and disposal. The program is administered through a system of permits. To obtain a permit to operate a facility that is subject to RCRA, the facility owner must monitor the groundwater beneath and downgradient of the operation to determine if statistically significant increases in contaminant concentrations (higher than those occurring upgradient of the site) exist. If the monitoring program indicates that contaminant concentrations are increasing, the facility owner must determine whether concentrations exist at levels above predetermined groundwater protection standards. Where such standards are exceeded, the site owner must implement a "corrective
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants Figure 2-1 Steps in the RCRA corrective action process. Note: EPA = Environmental Protection Agency. action" program to clean up the contaminated groundwater and soil. Figure 2-1 shows the steps in the RCRA corrective action process. CERCLA authorized the federal government to require cleanup of abandoned or inactive facilities where groundwater and soil are contaminated. Under CERCLA, current and former site owners can be held liable for cleanup costs. CERCLA also established a federal fund, Superfund, to pay for cleanup of sites where responsible parties cannot be identified. Because CERCLA facilities are no longer active, the program, unlike RCRA, is not operated through a permit system. Rather, the federal government is charged with identifying the nation's most highly contaminated sites, listing them in a data base known as the National Priorities List (NPL), and ensuring that the sites are cleaned up. Figure 2-2 outlines the CERCLA remedial process. Although the regulatory mechanisms under RCRA and CERCLA differ, the processes for selecting cleanup remedies under the two
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants Figure 2-2 Steps in the CERCLA remedial process. Note: EPA = Environmental Protection Agency.
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants BOX 2-1 Feasibility Study Criteria for Evaluation of Alternative Remedies Under CERCLA CERCLA regulations require consideration of the nine evaluation criteria listed below when selecting among possible cleanup remedies. Not all of these criteria receive equal weight. The first two are threshold requirements. Any remedy selected must be protective of human health and the environment, and "applicable or relevant and appropriate requirements" (ARARs—other federal, state, or tribal laws that apply to a particular site cleanup) must be followed. The next five criteria are considered balancing criteria. The selected remedy must be cost effective and use permanent solutions and treatment to the maximum extent practicable. The last two criteria are modifying criteria. Threshold Criteria Overall protection of human health and environment Compliance with ARARs Balancing Criteria Long-term effectiveness and permanence Reduction of toxicity, mobility, or volume Short-term effectiveness Implementability Cost effectiveness Modifying Criteria Regulatory acceptance Community acceptance programs are similar. For example, CERCLA's remedial investigation/feasibility study corresponds to the RCRA facility investigation/corrective measures study (see Figures 2-1 and 2-2). Development of the CERCLA record of decision (ROD) corresponds to the RCRA remedy selection step. The two programs also require consideration of similar criteria when selecting cleanup remedies. CERCLA requires consideration of nine evaluation criteria (see Box 2-1), and nearly the same set of criteria are used in remedy selection under RCRA. The groundwater and soil cleanup goals under the two programs are similar as well, as discussed below. A significant difference between the two programs is CERCLA's inclusion of a specific step in the time sequence of remedy selection for public comment; opportunities for public comment are less prominent under RCRA. The fourth law listed in Table 2-1, the Uranium Mill Tailings Remediation Control Act (UMTRCA), applies to 24 former uranium
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants ore mining and processing sites where cleanup is being overseen by DOE (EPA, 1995). These sites generally consist of mine tailings piles and groundwater and soil originating from these piles. When Congress enacted this legislation in 1978, members of Congress directed DOE to take charge of cleaning up 22 sites specifically identified in the legislation; DOE has since added two more sites to the list. The Environmental Protection Agency (EPA) oversees DOE's cleanup of UMTRCA sites, in cooperation with the Nuclear Regulatory Commission, according to a cleanup process and set of cleanup standards developed specifically for UMTRCA. Because UMTRCA applies to a small and unique subset of DOE sites, most of the discussion in this chapter focuses on RCRA and CERCLA. The Safe Drinking Water Act (SDWA) and the Clean Water Act (CWA), listed fifth and sixth in Table 2-1, do not directly regulate cleanup of contaminated groundwater and soil at DOE installations but rather provide the basis for setting groundwater and soil cleanup goals. The Toxic Substances Control Act, listed last in the table, has limited applicability to DOE groundwater and soil remediation projects; it includes special management provisions for cleanup of material containing polychlorinated biphenyls (PCBs), found as environmental contaminants at many DOE facilities. BASELINE CLEANUP GOALS Prior to assessing which remedial technologies might be applicable to a site, site managers must determine the remediation goals, including the targeted cleanup concentrations for each constituent in groundwater, soils, and other media, as appropriate. The baseline standards used as cleanup goals vary somewhat depending on the regulatory program and the individual regulators involved in overseeing a specific site, but in general, cleanup goals under CERCLA and RCRA are intended to be consistent. Groundwater Baseline Cleanup Goals Guided by the Safe Drinking Water Act, EPA and state agencies have established public drinking water standards for many compounds. EPA refers to these standards as "maximum contaminant levels" (MCLs). MCLs are established based on risk (toxicity and carcinogenicity), capability of drinking water treatment technologies to remove the particular contaminant, and cost considerations. MCLs apply to drinking water supplies. Groundwater may serve as a drinking water supply; therefore
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants Table 2-3 Maximum Contaminant Levels for Significant DOE Contaminants Contaminant MCL Constituents from DNAPLs Trichloroethylene 0.005 mg/liter Tetrachloroethylene 0.005 mg/liter Vinyl chloride 0.002 mg/liter cis-1,2-Dichloroethylene 0.07 mg/liter Metals Chromium (total) 0.1 mg/liter Uranium 0.020 mg/liter Radioactivity Beta particle and photon activity 4 mrem Gross alpha particle activity 15 pCi/liter Combined Ra-226 and Ra-228 5 pCi/liter Radon (1991 proposed) 300 pCi/liter the most common cleanup standards for groundwater at RCRA and CERCLA sites are MCLs. EPA has developed MCLs for organic chemicals, inorganic chemicals, and radionuclides. Table 2-3 lists the MCLs for organic chemicals that can dissolve from dense nonaqueous-phase liquids (DNAPLs) frequently identified at DOE facilities and for chromium, uranium, and radioactivity measures. The MCL for uranium is based on toxicity rather than radioactivity. For radionuclides, such as strontium-90, that emit beta particles and gamma rays, the MCL is based on dose equivalent (the effective radiation dose that the body receives), whereas for other radionuclides, the MCL is based on activity (the number of disintegrations of the radioactive compound per unit time). Within the RCRA program, provisions have been made for development of site-specific "alternate concentration limits" (ACLs) that can serve as cleanup goals for contaminated groundwater in place of MCLs. A corresponding procedure is available under CERCLA as part of the process of evaluating what are known as "applicable or relevant and appropriate requirements" (ARARs, which are environmental laws other than CERCLA that might apply to the site and that must be considered in setting cleanup goals). ACLs are derived through well-established procedures based on toxicity and exposure routes. Site usage and access to groundwater are important considerations.
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants Frequently, ACLs are less stringent than MCLs, allowing higher concentrations of contaminants to remain in place. Another situation in which cleanup targets other than MCLs may be used is when groundwater is not suitable for drinking. EPA has a groundwater classification system that identifies groundwater as class I: special groundwater (irreplaceable source or potential source of drinking water), class II: groundwater currently or potentially a source of drinking water, or class III: groundwater not a source of drinking water due to insufficient yield, high salinity, or contamination that cannot be reasonably treated. When groundwater fits class III, cleanup to goals other than MCLs is allowable. Substantial variability exists among EPA regions and individual case managers in allowing the use of groundwater cleanup goals other than MCLs. Additionally, there are large differences in cleanup levels and types of groundwater classifications among individual states. At DOE sites, both the state within which the site is located and the EPA have influence over the required cleanup levels. Nonetheless, despite the occasional use of ACLs and the classification of some groundwater as nonpotable, MCLs have historically served as baseline standards for groundwater cleanup at RCRA and CERCLA sites. EPA has established a separate set of groundwater cleanup targets under UMTRCA. Table 2-4 lists these requirements. For contaminants for which no goal has been established under UMTRCA, cleanup must achieve background levels. Alternate concentration limits are also allowable if DOE determines that the contaminants "will not pose a substantial present or potential hazard to human health and the environment as long as the alternate concentration limit is not exceeded," according to UMTRCA regulatory documents (40 C.F.R. 192). Soil Baseline Cleanup Goals For contaminated soils, there is no ARAR equivalent to the drinking water MCL. Until recently, soil cleanup goals were negotiated on a case-by-case basis, which increased the time to develop cleanup goals and costs and resulted in cleanup requirements that varied with location. Recognizing this limitation, EPA (1996) developed soil screening guidance for the establishment of cleanup levels. The soil screening guidance provides a tiered approach to estimate soil screening levels (SSLs) that may serve as preliminary remediation goals under certain
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants their own policies and guidance documents for natural attenuation. EPA's monitored natural attenuation guidance, however, cautions that its own policy, rather than these other documents, will provide the basis for approving the use of monitored natural attenuation. It states that non-EPA natural attenuation guidance manuals are not ''officially endorsed by the EPA, and all parties should clearly understand that such guidances do not in any way replace current EPA ... guidances or policies addressing the remedy selection process.'' Changes to Records of Decision Until the mid-1990s, changes to CERCLA RODs in order to allow the use of a more effective technology were extremely rare. The inability to change to a different remediation technology once the ROD had been signed created a barrier to the use of innovative remediation technologies (NRC, 1997), both at DOE sites and elsewhere. Years can pass between signing of the ROD and construction of the cleanup remedy (Guerrero, 1998). During this time, new technologies may emerge that could improve the prospects for site cleanup or reduce costs. Since 1995, EPA has changed its policies concerning ROD revisions and increasingly is allowing modifications to remedies specified in RODs to reflect new information about cleanup technologies or new understanding about the site. DOE and SCFA managers must be familiar with these policy changes because the new policies open an avenue for increasing use of innovative, cost-saving remedies at DOE sites. In 1996 and 1997, EPA approved remedy changes for groundwater and/or soil in existing RODs at 130 CERCLA sites. As shown in Table 2-6, the greatest number of changes (35) were approved to allow modifications to the design of the original remedy, often to reflect new performance data. Conventional remedies were changed to innovative remedies at another 11 sites. At nine sites, conventional pump-and-treat systems were eliminated and changed to monitored natural attenuation. Changes in required cleanup levels (usually to less stringent levels) were also allowed at a number of sites. In addition to allowing more flexibility in changes to remedies once RODs are signed, EPA has instituted a formal program to review all planned high-cost remedies, either just before the ROD is signed or (in a few cases) after the ROD is signed (Laws, 1995; Luftig, 1996). These reviews are carried out by the National Remedy Review Board, formed in January 1996. The review board formally assesses planned remedies for all non-DOE sites for which the action costs more than $30 million or for which the remedy costs more than $10
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants Table 2-6 Changes in CERCLA RODs for Groundwater and Soil Contamination, 1996–1997 Reason for Change Number of Sites Minor modification of original remedy designa 35 Treatment of full site changed to treatment of hot spots, or boundaries of remedy area decreased 5 Boundaries of remedy area increased 3 Change in required cleanup levels, intended land use, number of contaminants covered, or regulatory authority 20 Conventional remedy changed to innovative remedy 11 Innovative remedy changed to poor or uncertain performance 8 Pump-and-treat system changed to monitored natural attenuation 9 Pump-and-treat system changed to containment and/or monitoring 5 Pump-and-treat system downsized 5 In situ soil treatment or containment changed to ex situ treatment 6 Soil remedy changed to capping and/or containment 8 On-site soil treatment changed to off-site disposal or treatment 12 Off-site treatment or disposal changed to on-site treatment or disposal 3 Cleanup goals achieved; treatment discontinued 3 Change in duration of monitoring 1 Other 2 NOTE: Categories were based on interpretation of data provided by M. Charsky, EPA, 1998. Total number of sites with ROD changes is 130. Changes occurred for more than one reason at some sites. a Modifications include changes in treatment system for extracted water, location for soil disposal, design of incinerator, design of landfill, and others. million and is 50 percent more costly than the least-cost alternative that can meet cleanup criteria for the site. For DOE sites, the thresholds for review are $75 million and $25 million, respectively. The review board consists of managers and senior scientific staff from EPA headquarters in Washington and the regional offices. Following its review of a high-cost site, the review board issues recommendations to EPA decision makers in the region in which the site is located. The decision makers are not required to adopt the board's recommendations but must, at a minimum, prepare a written response indicating the logic of the choice to address or not address the board's concerns. The board reviewed 23 cleanup decisions, including two at DOE's Fernald facility and one at Oak Ridge National Laboratory, between its formation and January 1998 (NRRB, 1998).
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants The existence of this board may trigger the search for more cost-effective solutions for high-cost sites; it may prompt site managers to seek new technologies that will reduce cleanup costs to levels below the board's threshold cost criteria so that they can avoid having to undergo the formal review process. Brownfields Programs Although historically the goal of contaminated site cleanup programs has been to return sites to conditions that would allow unrestricted future use, increasing numbers of sites are now being cleaned up to levels safe for industrial and commercial use but not for residential use. Many of these sites are being restored under the auspices of "brownfields" programs. Brownfields are former commercial and industrial facilities that have been idled due in part to contamination problems and that could be returned to productive use provided some of the contamination can be removed. In general, sites cleaned up under brownfields programs can be converted to new uses much more rapidly than those restored under CERCLA and RCRA because the regulatory process is much less cumbersome and because cleanup standards are scaled back to provide protection for commercial and industrial users but not for potential residential users of the property. Some DOE installations, especially those that are near metropolitan areas and that DOE would like to turn over to the private sector, could be restored under brownfields programs. DOE and SCFA managers need to be familiar with the scope of these programs because their cleanup goals typically differ from those of CERCLA and RCRA, and thus the suite of possible remediation approaches differs as well. More than 200 contaminated sites across the country are now receiving funding from EPA for brownfields cleanups under the President's Brownfields Initiative, launched in November 1993 (EPA Region 8, 1998). Under this initiative, site owners or affected communities can apply for grants of up to $200,000 to serve as seed money for brownfields cleanups. Past projects have used this funding for gathering more detailed site characterization data to clarify the nature and extent of contamination, preparing redevelopment plans, setting cleanup priorities, and establishing working relationships with concerned citizens. EPA's brownfields funds can be used for federal facilities, such as DOE installations, as well as for private-sector sites. Many state and local governments have also created special programs to encourage redevelopment of brownfields (GAO, 1995). Key to these programs is reducing the fear of future liability for contami-
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants nation. In the past, the resale and reuse of idle contaminated property have been hindered by fear that the new owner or a lender who provides funding for the owner will be held liable for contamination discovered onsite, even if the owner and lender were not responsible for the contamination. Many state and local governments have established mechanisms to protect purchasers and lenders against liability; these mechanisms include special legislation and written covenants not to sue. Also available through some of these programs are loans for redevelopment. Key to brownfields programs is a formal change in the allowable land use for the site once cleanup has been completed. Case studies have shown that land use provisions have enormous effects on the residual risk at a site once a site is cleaned up. For example, Katsumata and Kastenberg (1997) demonstrated that at one CERCLA site, scenarios that assumed future residential use of the site produced risks from one to three orders of magnitude greater than scenarios assuming continued industrial use of the property. This difference was due to different assumptions about where and how humans would be exposed to the contamination. Further, they demonstrated that the planned cleanup remedy for the site (involving excavation of the soil and pumping and treating of groundwater) would not reduce risk sufficiently to protect future residential users even though the remedy was intended to do so; remaining risks would exceed EPA's general allowable threshold of one excess cancer case per 10,000 residents. The planned remedy would, however, be sufficient to reduce risks to below the 1-in-10,000 threshold for workers at a future industrial facility located on the site. The suite of acceptable remediation technology alternatives is thus likely to be broader at brownfield sites than at sites restored to residential use standards. SCFA may want to consider alternative possible cleanup end points and the availability of technologies that can achieve these end points in planning its remediation technology development program. Involvement in brownfields programs is a potentially important component of DOE's remediation strategy for some of its contaminated installations. DOE has had limited involvement in brownfields programs so far. DOE is a member of the Interagency Working Group on Brownfields (established in 1996 as a forum for information exchange among federal agencies) and in 1997 provided $315,000 to begin working with communities at DOE installations in potential brownfields areas (EPA, 1997a).
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants Risk-Based Corrective Action Programs An increasing number of state environmental agencies are adopting a process known as "risk-based corrective action" (RBCA) to evaluate and select cleanup remedies for sites that the states oversee. The RBCA process was developed by the American Society for Testing and Materials (ASTM) and published in the form of two industrial standard guides (ASTM, 1995, 1998). The first standard guide, published in 1995, applies to sites contaminated with petroleum hydrocarbons. The second, published in 1998, applies to sites with other chemical contaminants. Most states allow use of the RBCA process or a variant. As of October 1998, 14 states had formally adopted ASTM's RBCA standard as part of their regulatory process for petroleum-contaminated sites, and 27 additional states were developing RBCA programs (S. McNeely, EPA Office of Underground Storage Tanks, personal communication, 1998). In addition, the Air Force has developed a methodology, the Enhanced Site Specific Risk Assessment process, similar to RBCA and is conducting an in-depth feasibility analysis to examine how the methodology will fit into the cleanup process. The Navy is considering using RBCA or a similar process for cleaning up its sites, as well. DOE cleanup managers and SCFA should be familiar with the RBCA process because its use may eventually expand beyond the cleanup of petroleum-contaminated sites, and it therefore may influence the selection of cleanup remedies. RBCA integrates site assessment, remedy selection, and site monitoring through a tiered approach involving increasingly sophisticated levels of data collection and analysis (see Figure 2-4). The initial site assessment identifies source areas of chemicals of concern, potential human and environmental receptors, and potentially significant transport pathways. Sites are then classified and initial response actions identified based on the urgency of need (immediate, zero to two years, more than two years, no action). Based on the information obtained during the initial site assessment, project managers perform a "tier 1" evaluation (according to steps specifically outlined in the RBCA standard) to determine whether the site qualifies for quick regulatory closure or warrants a more site-specific evaluation. In determining risk, the tier 1 evaluation uses standard exposure scenarios with current reasonable maximum exposure assumptions and toxicological parameters. When the tier 1 evaluation indicates a possible risk to human health, project managers can decide to clean up the site or proceed to a more detailed site risk evaluation, known as tier 2. At the end of tier 2, project managers again have the option of closing
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants Figure 2-4 Steps in the ASTM RBCA process. Source: ASTM, 1995.
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants the site (if the more detailed evaluation shows that there is no risk), cleaning up the site to protect against risks as computed in tier 2, or proceeding to a final level of highly detailed evaluation, known as tier 3. Tier 3 provides the flexibility for more complex calculations to establish cleanup levels and may include additional site assessment, probabilistic evaluations, and sophisticated chemical fate and transport models. In a recent review of application of RBCA and other risk-based approaches for cleanup of Navy installations, the National Research Council (NRC, 1998) concluded that the RBCA approach has several advantages, including the following: Site assessment activities can be focused on collecting only information that is necessary to make risk-based corrective action decisions. Remedial decisions may be accelerated and costs therefore reduced. Resources can be focused on sites that pose the greatest risk to human health. However, the NRC also concluded that the existing RBCA standards would not be suitable for application at Navy sites because the standards lack 6 of 11 criteria that the NRC determined are essential for the successful implementation of risk-based approaches at Navy facilities. In particular, the RBCA standards are lacking in the following: They do not provide for integrated assessment of multiple sites affecting the same human or ecological receptors at the same installation. They lack sufficient mechanisms for considering critical uncertainties in site assessment, such as those associated with models of contaminant fate and transport and with estimating health and ecological risks. They do not adequately account for long-term risks that may remain in place even after cleanup has been completed to the extent practicable. They do not adequately address the need for public involvement in remedy selection. They did not undergo external, independent scientific peer review and public review. It is not clear whether the standards can satisfy all of the regulatory requirements under Superfund and RCRA. The NRC recommended that the Navy develop a risk-based methodology for its Environmental Restoration Program that satisfies 11
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants BOX 2-3 NRC's Criteria for a Risk-Based Remediation Process In a 1998 review of the potential for application of risk-based methodologies in the cleanup of contaminated Navy bases, the NRC concluded that in order to succeed, any risk-based approach must meet the following criteria: It facilitates prioritization of contaminated sites at individual installations. It provides a mechanism for increasing the complexity of the remedial investigation when appropriate. It provides guidance on data collection needed to support the development of site-specific cleanup goals. It provides for integrated assessment of sites affecting the same human or ecological receptors. It encourages 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. It considers relevant uncertainties. It provides a mechanism for integrating the selection of the remedial option with the establishment of remedial goals. It also provides quantitative tools for developing risk management strategies. It has options to revisit sites over the long term. It is implemented in a public setting with all stakeholders involved. It undergoes both external, independent scientific peer review and public review. It complies with relevant state and federal statutory programs for environmental cleanup. SOURCE: NRC, 1998. basic criteria (see Box 2-3). Such criteria might also be applied to the use of risk-based cleanup processes at DOE installations. CONCLUSIONS An understanding of DOE's changing legal obligations for the cleanup of contaminated groundwater and soil is critical to the effective administration of SCFA's program for developing new groundwater and soil cleanup technologies. SCFA must tailor its technology development program to ensure that DOE has the tools necessary to meet applicable legal requirements. Although groundwater and soil restoration goals have not yet been specified for many DOE sites, when these goals are established they must satisfy the requirements of applicable regulations, generally RCRA, CERCLA, UMTRCA, or a combination of these.
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants Policies concerning cleanup requirements for groundwater and soil are evolving rapidly. SCFA managers need to keep track of these changes because new policies may affect the selection of cleanup goals for DOE sites and, correspondingly, the suite of possible remediation technologies for achieving those goals. Key trends for SCFA to monitor include the following: Increasing use of technical impracticability waivers. EPA has clarified its policies for determining when cleanup to baseline standards is infeasible. SCFA has to plan for the development of remedial alternatives (including containment systems) that can be used at sites where technical impracticability waivers are granted. Further, SCFA has to continue to pursue development of technologies that can clean up these difficult sites because issuance of a waiver does not remove DOE's long-term liability for a site. Increasing use of monitored natural attenuation. Use of monitored natural attenuation in place of or in conjunction with active cleanup remedies is increasing at contaminated sites nationwide, but implementing natural attenuation at DOE sites may require additional research to develop methods for predicting the fate of contaminants under conditions of natural attenuation. SCFA must understand current policy requirements for implementation of monitored natural attenuation and determine what additional research will be necessary for DOE to meet these requirements at appropriate sites. An increase in the number of changes to groundwater and soil remedies in CERCLA RODs. At an increasing number of CERCLA sites, remediation technologies specified in RODs are being changed to reflect new technological developments or new understanding about the site. SCFA could play a useful role in determining where innovative technologies might provide more effective solutions than technologies specified in current RODs. Emergence of brownfields programs. Increasing numbers of sites in former industrial areas are being cleaned up to industrial reuse standards, rather than residential use standards, under brownfields programs. DOE is eligible for participation in these programs, and SCFA should keep track of the types of technologies that might be appropriate for remediation under brownfield scenarios. Emergence of risk-based corrective action programs. Increasing numbers of organizations are developing risk-based procedures designed to set cleanup priorities among contaminated sites. If DOE managers decide such a process is appropriate for their sites, SCFA could play a role in developing the protocols for DOE. SCFA should be familiar with existing risk-based corrective action procedures developed by other organizations.
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants REFERENCES American Petroleum Institute. 1997. Methods for Measuring Indicators of Intrinsic Bioremediation: Guidance Manual. Washington, D.C.: American Petroleum Institute. ASTM (American Society for Testing and Materials). 1995. Standard Guide for Risk-Based Corrective Action at Petroleum Release Sites (E1739-95). Annual Book of ASTM Standards. West Conshocken, Pa.: ASTM. ASTM. 1997. Standard Guide for Remediation of Groundwater by Natural Attenuation at Petroleum Release Sites: Draft. February 4. Philadelphia: ASTM. ASTM. 1998. Standard Provisional Guide for Risk-Based Corrective Actions (PS104-98). Annual Book of ASTM Standards. West Conshohocken, Pa.: ASTM. Brady, P. V., M. V. Brady, and D. J. Borns. 1997. Natural Attenuation: CERCLA, RBCA's and the Future of Environmental Remediation. Boca Raton, Fla.: Lewis Publishers. Brady, P. V., B. P. Spalding, K. M. Krupka, R. D. Waters, Pengchu Zhang, D. J. Borns, and W. D. Brady. 1998a. Site Screening and Technical Guidance for Monitored Natural Attenuation at DOE Sites. Albuquerque, N.M.: Sandia National Laboratories. Brady, P. V., B. P. Spalding, K. M. Krupka, R. D. Waters, Penchus Zhang, and D. J. Borns. 1998b. Site Screening for Monitored Natural Attenuation with MNA Toolbox. Albuquerque, N.M.: Sandia National Laboratories. Buscheck, T., and K. O'Reilly. 1995. Protocol for Monitoring Intrinsic Bioremediation in Groundwater. Richmond, Calif.: Chevron Research and Technology Company. Buscheck, T., and K. O'Reilly. 1997. Protocol for Monitoring Natural Attenuation of Chlorinated Solvents in Groundwater. Richmond, Calif.: Chevron Research and Technology Company. DOE (Department of Energy). 1998. Accelerating Cleanup: Paths to Closure. DOE/CM-0362. Washington, D.C.: DOE, Office of Environmental Management. EPA (Environmental Protection Agency). 1990. National Oil and Hazardous Substances Pollution Contingency Plan; Final Rule. Federal Register 55(46). EPA. 1993. Guidance for Evaluating the Technical Impracticability of Ground-Water Restoration: Interim Final. Directive 9234.2–25. Washington, D.C.: EPA, Office of Solid Waste and Emergency Response. EPA. 1995. Technical Resource Document: Extraction and Beneficiation of Ores and Minerals, Vol. 5—Uranium . EPA 530-R-94-032. Washington, D.C.: EPA, Office of Solid Waste, Special Waste Branch. EPA. 1996. Presumptive Response Strategy and Ex-situ Treatment Technologies for Contaminated Groundwater at CERCLA Sites. EPA 540-R-96-023. Washington, D.C.: EPA, Office of Solid Waste and Emergency Response. EPA. 1997a. Brownfields National Partnership Action Agenda. EPA 500-F-97-090. Washington, D.C.: EPA, Office of Outreach and Special Projects. http://www.epa.gov/swerosps/bf/html-doc/97aa_fs.htm. EPA. 1998. Technical Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Groundwater. EPA/600/R-98/128. Washington, D.C.: EPA, Office of Research and Development. EPA. 1999. Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action, and Underground Storage Tank Sites. Directive Number 9200.4–17p. Washington, D.C.: EPA, Office of Solid Waste and Emergency Response. EPA Region 8. 1998. Brownfields Pilot Grant Announced for Missoula, MT. Denver, Colo.: EPA Region 8, Office of Communication and Public Involvement. http://www.epa.gov/unix0008/html/news/news98/brnfmis.html. GAO (U.S. General Accounting Office). 1994. Nuclear Cleanup: Difficulties in Coordinating Activities Under Two Environmental Laws. GAO/RCED-95-66. Washington, D.C.: GAO.
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Ground Water & Soil Cleanup: Improving Management of Persistent Contaminants GAO. 1995. Community Development: Reuse of Urban Industrial Sites. GAO/RCED-95-172. Washington, D.C.: GAO. Guerrero, P. F. 1998. Superfund: Times to complete site listing and cleanup. Testimony before the Subcommittee on Finance and Hazardous Materials, Committee on Commerce, House of Representatives, February 4. GAO/T-RCED-98-74. Washington, D.C.: U.S. General Accounting Office. Guimond, R. J. 1993. Memorandum. Transmittal of OSWER directive 9234.2–25: ''Guidance for Evaluating the Technical Impracticability of Ground-Water Restoration.'' Office of Solid Waste and Emergency Response, Washington, D.C.: Environmental Protection Agency. Katsumata, P. T., and W. E. Kastenberg. 1997. On the impact of future land use assumptions on risk analysis for Superfund sites. Journal of the Air and Waste Management Association 47(August):881–889. Laws, E. P. 1995. Memorandum. November 28: Formation of National Superfund Remedy Review Board. Washington, D.C.: Environmental Protection Agency, Office of Solid Waste and Emergency Response. Luftig, S. D. 1996. Memorandum. September 26: National Remedy Review Board. Washington, D.C.: Environmental Protection Agency, Office of Solid Waste and Emergency Response. Minnesota Pollution Control Agency. 1997. Draft Guidelines: Natural Attenuation of Chlorinated Solvents in Groundwater. Working Draft. December 12. St. Paul, Minn.: Minnesota Pollution Control Agency. NRC (National Research Council). 1993. Pesticides in the Diets of Infants and Children. Washington, D.C.: National Academy Press. NRC. 1994. Alternatives for Groundwater Cleanup. Washington, D.C.: National Academy Press. NRC. 1997. Innovations in Groundwater and Soil Cleanup: From Concept to Commercialization. Washington, D.C.: National Academy Press. NRC. 1998. Assessing the Use of Risk-Based Methodologies for Environmental Remediation at Naval Facilities. Washington, D.C.: National Academy Press. NRRB (National Remedy Review Board). 1998. NRB Fiscal Year 1997 Progress Report. Washington, D.C.: Environmental Protection Agency, Office of Solid Waste and Emergency Response. http://www.epa.gov/superfund/oerr/nrrb/report.htm Probst, K. N., and M. H. McGovern. 1998. Long-Term Stewardship and the Nuclear Weapons Complex: The Challenge Ahead. Washington, D.C.: Resources for the Future. Remediation Technologies Development Forum. 1997. Natural Attenuation of Chlorinated Solvents in Groundwater: Principles and Practices. Washington, D.C.: Environmental Protection Agency, Technology Innovation Office. Wiedemeier, T. H., and F. H. Chapelle. 1998. Technical Guidelines for Evaluating Monitored Natural Attenuation at Naval and Marine Corps Facilities: Draft, Revision 2. Washington, D.C.: Department of the Navy. Wiedemeier, T., J. T. Wilson, D. H. Kampbell, R. N. Miller, and J. E. Hansen. 1995. Technical Protocol for Implementing Intrinsic Remediation with Long-Term Monitoring for Natural Attenuation of Fuel Contamination Dissolved in Groundwater, Volumes 1 and 2. San Antonio, Tex.: Air Force Center for Environmental Excellence, Brooks Air Force Base. Wiedemeier, T. H., M. A. Swanson, D. E. Moutoux, E. K. Gordon, J. T. Wilson, B. H. Wilson, J. H. Kampbell, J. E. Hansen, P. Haas, and F. H. Chapelle. 1997. Technical Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Groundwater. San Antonio, Tex.: Air Force Center for Environmental Excellence, Brooks Air Force Base.
Representative terms from entire chapter: