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.
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
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. |
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
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
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
Balancing Criteria
Modifying Criteria
|
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
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
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.
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
Table 2-4 Groundwater Cleanup Standards for UMTRCA Sites
Contaminant |
Maximum Allowable Concentration (mg/liter, unless otherwise indicated) |
Arsenic |
0.05 |
Barium |
1.0 |
Cadmium |
0.01 |
Chromium |
0.05 |
Lead |
0.05 |
Mercury |
0.002 |
Selenium |
0.01 |
Silver |
0.05 |
Nitrate (as nitrogen) |
10 |
Molybdenum |
0.1 |
Combined radium-226 and radium-228 |
5 pCi/liter |
Combined uranium-234 and uranium-238 |
30 pCi/liter |
Gross alpha-particle activity (excluding radon and uranium) |
15 pCi/liter |
Endrin |
0.0002 |
Lindane |
0.004 |
Methoxychlor |
0.1 |
Toxaphene |
0.005 |
2,4-Dichlorophenoxyacetic acid |
0.1 |
2,4,4-Trichlorophenoxypropionic acid |
0.01 |
SOURCE: 40 C.F.R. 192. |
conditions. The soil screening framework considers potential exposures from ingestion of soil, inhalation of volatile compounds and fugitive dusts, and ingestion of groundwater contaminated by migration of chemicals through the soil to an underlying drinking water aquifer. SSLs are generally based on a 10-6 risk (meaning one excess cancer death per million people) for carcinogens or a hazard quotient of 1 (the exposure concentration divided by the "safe" dose) for noncarcinogens. SSLs apply at the point of potential exposure. For groundwater pathways, SSLs are back-calculated using drinking water standards at the site boundary.
Points of Compliance
Under CERCLA, groundwater cleanup goals must be achieved throughout the contaminated site, with the exception of underneath "waste management" areas. According to the National Contingency Plan (NCP), which is the primary EPA regulatory document for implementing CERCLA,
For groundwater, remediation levels should generally be attained
throughout the contaminated plume, or at and beyond the edge of the waste management area when waste is left in place (EPA, 1990).
According to this policy, waste management areas are landfills that will be contained when remediation of the rest of the site is completed. EPA guidance documents indicate that DNAPLs that remain in place are not considered waste management areas (EPA, 1996). If DNAPLs cannot be cleaned up due to technical limitations, then ARARs should be waived, rather than changing the point of compliance for cleanup, according to EPA guidance documents (EPA, 1996). The NCP allows for changes in points of compliance under specific circumstances, including situations in which ''there would be little likelihood of exposure due to the remoteness of the site ... provided contamination in the aquifer is controlled from further migration'' (EPA, 1990).
Points of compliance for soil cleanup under CERCLA are determined on a site-specific basis. In general, any soil containing concentrations of contaminants above the predetermined cleanup standards for the site must be treated. Containment of contaminated soil onsite is permissible, but CERCLA indicates that treatment should be attempted for "hot spots" containing high concentrations of contaminants. Where contaminated soil is contained, the point of compliance is the edge of the containment system.
According to EPA policy, points of compliance at RCRA sites are to be determined according to the same standards as points of compliance at CERCLA sites. In some instances, however, RCRA regulatory managers at specific sites have not followed the CERCLA policy, and the property boundary has been used as the point of compliance (K. Lovelace, Environmental Protection Agency, personal communication, 1998). This difference may be due to the fact that EPA generally empowers state agencies to implement RCRA, whereas EPA itself oversees CERCLA cleanups.
Like CERCLA and RCRA sites, the point of compliance at UMTRCA sites is the edge of any location in which remaining waste is to be contained in place. According to the policy for UMTRCA cleanups, the point of compliance is located "at the hydraulically downgradient limit of the disposal area plus the area taken up by any liner, dike, or other barrier designed to contain the residual radioactive material" (40 C.F.R. 192.02[c]).
Cleanup Goals at DOE Installations
Groundwater and soil cleanup goals at DOE installations must satisfy the requirements of applicable regulations, which in most cases means regulations under CERCLA and RCRA. Box 2-2 shows ground-
BOX 2-2 Example Baseline Cleanup Goals at DOE Sites The following are sample cleanup goals established for select sites at a few of the major DOE installations. Information about cleanup goals at each of these sites was obtained from the ROD for the installation. Hanford 1100 Area, Operable Unit 1 This 13-km2 site is located in an area of the Hanford installation known as the Arid Lands Ecology (ALE) reserve. The reserve is currently used for ecological research but formerly contained a NIKE missile base and control center. Sources of contamination in operable unit 1 of the site include a battery acid pit, paint solvent pit, antifreeze and degreaser pit, antifreeze tank, and landfill. Groundwater and soil are contaminated. The groundwater cleanup goal for the site is to reduce trichloroethylene (TCE) contamination to less than 0.5 mg/liter via natural attenuation. The ROD states that this concentration "is based on SDWA MCLs," but the MCL for TCE is 0.005 mg/liter, well below the goal specified in the ROD. Soil cleanup goals for the site are based on state standards and include benzene, 0.5 mg/kg; toluene, 40 mg/kg; xylenes, 20 mg/kg; perchloroethylene (PCE), 0.5 mg/kg; TCE, 0.5 mg/kg; polycyclic aromatic hydrocarbons, 1 mg/kg; PCBs, 5.2 mg/kg; hexavalent chromium, 1,600 mg/kg; and lead, 250 mg/kg. 200 Area, 200-ZP-1 Operable Unit The 200 Area of Hanford, a 40-km2 (15-mi2) tract, contains several operable units where cleanup is occurring. The contamination in the 200-ZP-1 operable unit originated from discharges from Hanford's Plutonium Finishing Plant into three liquid waste disposal sites. Soil is contaminated with a mixture of carbon tetrachloride (CCl4) and plutonium. Almost all of the plutonium is bound to the soil, and very little has reached the groundwater, but the groundwater contains a plume of CCl4. Final soil and groundwater cleanup goals for this site have not been established. Meanwhile, an interim remedial measure is in place to stop the spread of the CCl4 plume in the groundwater by using a pump-and-treat system. Idaho National Engineering and Environmental Laboratory Test Area North This site is a 26-km2 (10-m2) area built in the 1950s to support the Aircraft Nuclear Propulsion Program sponsored by the Air Force and the Atomic Energy Commission. An injection well was used to dispose of industrial and sanitary wastes and wastewaters from 1953 until 1972. Groundwater at the site is contaminated. Cleanup goals for contaminated groundwater are based on MCLs and are as follows: TCE, 0.005 mg/liter; PCE, 0.005 mg/liter; lead, 0.05 mg/liter; and strontium-90, 300 pCi/liter. |
Pit 9 This site is a 4,000-m2 (1-acre) pit used to dispose of drums, boxes, and other large items between 1967 and 1969. Drums of waste, including sludge contaminated with a mixture of transuranic elements and organic solvents, and boxes containing empty contaminated drums from Rocky Flats, account for 3,100 m3 of the waste. Monitoring wells have indicated that the groundwater beneath Pit 9 is not contaminated. However, contaminants are present in soil and debris. Soil and debris cleanup goals for treated waste containing less than or equal to 100 pCi/g and being returned to Pit 9 are based on "maximum allowable leachate concentrations" for RCRA delisting and health risk-based levels: CCl4, 18 ms/kg; PCE, 45 ms/kg; 1,1,1-trichloroethane (1,1,1-TCA), 2,910 mg/kg; TCE, 15 mg/kg; potassium cyanide, 119 mg/kg; and sodium cyanide, 122 mg/kg. Soil and debris cleanup goals for treated waste residuals containing less than 10 pCi/g of radioactivity and being temporarily stored onsite are based on RCRA land disposal restrictions: CCl4, 5.6 mg/kg; PCE, 5.6 mg/kg; 1,1,1-TCA, 5.6 mg/kg; TCE, 5.6 mg/kg; potassium cyanide, 122 mg/kg; lead, 5 mg/liter; and mercury, 260 mg/kg. Oak Ridge Reservation, Operable Unit 16 This site includes two former disposal ponds used for waste from the former K-25 uranium enrichment facilities. DOE removed the remaining sludge from both ponds in 1987 and 1988 to comply with RCRA requirements for site closure and subsequently discovered contamination in the underlying soil and groundwater. Groundwater cleanup goals and a groundwater remediation plan for the site have yet to be established, but soil cleanup goals have been determined. According to the ROD, the soil cleanup goals are based on "a health-risk level of 10-6, EPA-recommended equations for calculating preliminary remediation goals for radionuclides in soil, and RCRA clean closure requirements." The soil cleanup goals include the following: americium-241, 0.002 pCi/g; cadmium, 1 mg/kg; cesium-137, 0.004 pCi/g; chromium, 0.000002 mg/m3; cobalt-60, 0.002 pCi/g; europium-154, 0.004 pCi/g; manganese, 156 mg/kg; mercury, 0.1 mg/kg; neptunium-237, 0.002 pCi/g; nickel, 130 mg/kg; potassium-40, 0.033 pCi/g; technetium-99, 1.8 pCi/g; thorium-230, 0.003 pCi/g; uranium-234, 0.003 pCi/g; uranium-235, 0.007 pCi/g; uranium-238, 0.001 pCi/g; and zinc, 52 mg/kg. Savannah River Site All groundwater contamination sites mentioned in the ROD for the Savannah River Site either (1) require no further action under CERCLA because contamination is being managed under RCRA or (2) have no specified cleanup goals because at this time only interim actions have been determined. |
water and soil cleanup standards for a sampling of sites from DOE installations, based on a review of RODs for these installations. The box includes information from sites where cleanup goals have not yet been specified. An informal review of RODs indicates that goals have yet to be determined for most of the DOE sites.
CHANGING REGULATORY ENVIRONMENT
Although baseline cleanup standards generally must be achieved across most of the area of a contaminated site, changes in these standards and in the overall process of site cleanup under RCRA and CERCLA are becoming increasingly common. The driver for some of these changes is recognition of the limits of available technologies for site cleanup: achieving existing baseline standards is not possible for certain types of contamination scenarios with existing technologies (NRC, 1994). The driver for other changes in regulatory practice is recognition of the extremely high costs of cleanup using conventional methods. SCFA managers need to be aware of this changing regulatory environment because it opens up new possibilities for site cleanup at DOE installations. Technologies that are unable to achieve baseline standards or that regulators might not have considered in the past may be acceptable for use in the new regulatory environment.
Five broad emerging trends, discussed below, show how the nature of contaminated site regulation is changing: (1) increasing interest in the use of "technical impracticability waivers" where ground-water restoration is not technologically feasible; (2) increasing use of monitored natural attenuation (intrinsic remediation in place of engineered cleanup systems; (3) increasing number of changes to ground-water and soil remedies specified in CERCLA RODs; (4) emergence of brownfields programs allowing site cleanup to industrial reuse standards rather than residential standards; and (5) emergence of risk-based programs at the state level for assessing site cleanup requirements.
Technical Impracticability Waivers
Under both CERCLA and RCRA, required cleanup standards for contaminated groundwater and soil can be waived in cases where achieving these standards is not possible with existing technologies. For example, CERCLA states that cleanup standards can be waived if cleanup is "technically impracticable from an engineering perspective" (EPA, 1990). RCRA contains similar language. Both statutes state that engineering feasibility and reliability, rather than cost, should be the key considerations in determining the practicality of cleanup.
DOE's strategy for cleaning up its installations (known as the "Paths to Closure" Plan) emphasizes that because of the limitations of existing remediation technologies, groundwater contamination will remain at many sites after other cleanup goals are achieved (DOE, 1998). If this is the case, DOE will have to apply for waivers to
cleanup standards at many sites, and DOE's cleanup managers will have to be familiar with EPA's policies concerning cases where ground-water restoration is technically infeasible. Further, SCFA managers will have to be aware of what remedial alternatives are acceptable to EPA in cases where achievement of cleanup standards is infeasible because these will affect which technologies should be selected for development.
Prior to the early 1990s, regulatory policies for implementing the "technical impracticability" provisions of CERCLA and RCRA were ambiguous. In 1993, due to increasing recognition of the limitations of groundwater cleanup technologies, EPA issued a guidance document clarifying its policies on granting waivers to cleanup standards based on technical considerations and specifying how site owners should go about applying for such waivers (EPA, 1993). EPA intended that this guidance document, titled Guidance for Evaluating the Technical Impracticability of Ground-Water Restoration, would provide a consistent standard for use by EPA staff overseeing CERCLA and RCRA sites in deciding whether or not cleanup of groundwater is technically feasible. The cover memo (signed by the acting administrator of the CERCLA and RCRA programs) accompanying the guidance document states that "experience over the past decade has shown that achieving the required final cleanup standards may not be practicable at some sites due to the limitations of remediation technology" (Guimond, 1993).
Although the guidance document is applicable to all types of contaminants, it emphasizes DNAPLs. The guidance document states, "As proven technologies for the removal of certain types of DNAPL contamination do not exist yet, DNAPL sites are more likely to require TI [technical impracticability] evaluations than sites with other types of contamination." It indicates that up to 60 percent of CERCLA sites may contain DNAPLs, according to EPA surveys.
The key elements of the technical impracticability guidance document are its discussion of (1) the timing of decisions concerning the technical impracticability of cleanup, (2) alternative remedial strategies where cleanup is not possible, (3) long-term monitoring requirements for sites where cleanup goals are waived due to technical impracticability, and (4) types of data that must be provided to EPA to evaluate the technical feasibility of achieving cleanup standards.
Regarding timing, the guidance document specifies that in many cases, EPA staff should hold off on granting technical impracticability waivers until a full-scale cleanup system has been implemented and has failed to achieve cleanup standards. The document states, "EPA believes that, in many cases, TI decisions should be made only after
Table 2-5 Technical Impracticability Waivers in CERCLA RODs for Sites with Contaminated Groundwater, 1989–1997
interim or full-scale aquifer remediation systems are implemented because often it is difficult to predict the effectiveness of remedies based on limited site characterization data alone." It specifies that technical impracticability waivers can be granted prior to trying a full-scale remedy only "in cases where there is a high degree of certainty that cleanup levels cannot be achieved." Data from the CERCLA program indicate that, in general, EPA is following the policy of granting impracticability waivers in most cases only after full-scale remedies have been installed. Table 2-5 shows the number of technical impracticability waivers specified in RODs between 1989 and 1997; as shown, the number of sites with RODs specifying technical impracticability is still very small and has remained at a relatively constant level. Presumably, the number of such waivers is small because waivers are not generally granted without attempting cleanup. This requirement may pose difficulties for DOE in obtaining technical impracticability waivers, because full-scale groundwater cleanup systems are not yet in place for most sites.
The guidance also specifies that technical impracticability waivers must include alternative remedial strategies to protect public health and the environment when cleanup standards cannot be achieved. The alternative remedial strategy must document how exposure to the contamination will be prevented (for example, through restrictions on well construction), how the source of contamination will be controlled, and how plumes of dissolved contaminants emanating
from source areas will be managed. It suggests well construction and deed restrictions as possible exposure control methods. It also indicates that contaminant sources should be contained either hydraulically or physically to the maximum extent possible. Where sources are effectively contained, it requires that plumes of dissolved contaminants be restored to applicable standards. Where source containment is not possible, either plumes should be controlled hydraulically, less stringent cleanup levels can be established, or contaminants can be allowed to attenuate naturally, as long as exposure controls are in place. EPA's general preference for source containment may require that SCFA strengthen its efforts to help develop effective long-term containment systems.
The guidance document describes in detail the types of supporting information that site owners must provide when applying for technical impracticability waivers. Essentially, applications for such waivers must include the following five parts:
-
identification of required cleanup standards for which technical impracticability waivers are being sought;
-
description of the spatial area for which the waiver is being sought;
-
conceptual model showing site geology, hydrology, groundwater contamination sources, and contaminant transport and fate;
-
evaluation of the site's "restoration potential," to include
-
proof that contamination sources have been identified and will be removed or contained to the extent possible,
-
analysis of performance of any existing remediation systems,
-
predicted time to attain required cleanup levels with available technologies, and
-
evidence that no existing technology can attain required cleanup levels within a reasonable time period; and
-
estimates of the cost of existing or proposed remedy options.
Thus, for sites at which DOE believes that groundwater cleanup is not technically feasible, DOE managers will have to supply EPA with the above types of information.
One of the most important provisions of the technical impracticability guidance document is EPA's right to require additional work in future years at sites with technical impracticability waivers. Sites with such waivers remain "open" to future requirements by EPA. The document specifies that EPA will reassess CERCLA sites with such waivers every five years and will reassess RCRA sites periodically, as well. If new technologies emerge that might restore the groundwater, EPA can require that they be implemented. EPA will
also require continuous, long-term monitoring of these sites. Technical impracticability waivers therefore will not eliminate DOE's long-term liability for remaining contamination.
Monitored Natural Attenuation
Over the past two decades, a body of knowledge has accumulated indicating that some types of contaminants, especially petroleum hydrocarbons, can degrade naturally in the subsurface at relatively rapid rates (NRC, 1993). This knowledge is increasingly reflected in the practice of cleaning up contaminated sites. To a greater degree, regulators are approving the use of "natural attenuation," rather than engineered cleanup remedies, to solve groundwater contamination problems or reduce the size of the area treated with engineered remedies. Figure 2-3 shows the increase in the use of natural attenuation for contaminated groundwater at CERCLA sites between 1985 and 1995. DOE managers need to be aware of current regulatory
policies concerning the use of natural attenuation in order to determine whether this strategy may apply at some of their sites. SCFA has to be aware of these policies because the use of natural attenuation at DOE sites will require additional research for some types of contaminants and the development of better tools for monitoring the progress of natural attenuation.
The key EPA policy document pertaining to natural attenuation is a directive entitled Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action, and Underground Storage Tank Sites, finalized in 1999 (EPA, 1999). The directive codifies that natural attenuation can be an acceptable remedy for contaminated groundwater and soil at CERCLA and RCRA sites. Publication of this directive marked a change from the policies of the 1980s and early 1990s. In the earlier years, strong preference was given to engineered remedies (Brady et al., 1997), and natural attenuation was rarely used, as shown in Figure 2-3.
The directive defines monitored natural attenuation as "the reliance on natural attenuation processes ... to achieve site-specific remediation objectives within a time frame that is reasonable to that offered by other more active methods." According to the directive, the natural processes that can contribute to contaminant attenuation include biodegradation, dispersion, dilution, sorption to solid media, volatilization, and chemical or biological stabilization, transformation, or destruction.
The directive indicates that in order to apply for the use of monitored natural attenuation, site owners, with certain exceptions, must submit the following types of data:
-
historical groundwater and soil data showing a continuous trend of decreasing contaminant concentration or decreasing contaminant mass over time;
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hydrogeologic and geochemical data demonstrating indirectly the types of natural attenuation processes at work at the site and the rate at which these processes will reduce contaminant concentrations; and
-
data from microcosm studies conducted with contaminated media from the site directly proving that specific processes are active at the site.
The directive indicates that the first type of data will always be required. EPA will require the second type of data in all cases except when "EPA or the overseeing regulatory authority determines that historical data (number 1 above) are of sufficient quality and duration to support a decision to use MNA [monitored natural attenuation]." The third type of data will be required only where the first two types of data are "inadequate or inconclusive," according to the
directive. The directive does not contain specific guidance on what types of data are appropriate for these three categories or on how to gather such data.
The directive provides several caveats about the use of monitored natural attenuation that site managers must consider when assessing whether to apply for regulatory approval to use this remediation strategy. Key among the caveats are the following:
-
Active measures to control contaminant sources usually will be required even at sites where monitored natural attenuation is approved.
-
Site characterization data for natural attenuation will have to be more detailed than for other remedies.
-
Performance monitoring data for natural attenuation must be more detailed than for other remedies.
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The time frame for natural attenuation should not be excessively long compared to the time frame for engineered remedies.
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Contingency remedies will have to be specified in the event that natural attenuation fails.
Implementing natural attenuation remedies at DOE sites may thus require additional research to determine how to provide the three categories of data mentioned above, how best to control contaminant sources, how to monitor the site, and how best to predict the likely time frame for natural attenuation. Research on these topics is currently under way at some of DOE's national laboratories (see, for example, Brady et al., 1998a,b).
EPA and a variety of other organizations have also developed technical documents indicating how to assess sites for natural attenuation potential. The most detailed of these, providing guidelines on how to gather appropriate site data, were developed by the Air Force Center for Environmental Excellence and cover petroleum hydrocarbon and chlorinated solvent contamination (Wiedemeier et al., 1995, 1997). The EPA recently released a technical protocol similar to the Air Force protocol for evaluating natural attenuation potential at sites contaminated with chlorinated solvents (EPA, 1998). Other organizations that have developed natural attenuation protocols include the Navy (Wiedemeier and Chapelle, 1998); the American Society for Testing and Materials (1997); a few states (see, for example, Minnesota Pollution Control Agency, 1997); the Remediation Technologies Development Forum (1997); the American Petroleum Institute (1997); and Chevron Corporation (Buscheck and O'Reilly, 1995, 1997). DOE researchers at Sandia National Laboratories also recently developed a documententitled Site Screening and Technical Guidance for Monitored Natural Attenuation at DOE Sites (Brady et al., 1998a). Some states also have
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
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).
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-
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).
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
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.
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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.
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They did not undergo external, independent scientific peer review and public review.
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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
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:
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.
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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