United States Environmental Protection Agency Solid Waste and Emergency Response Publication No. 9355.4-01 FS August 1990 &EPA A Guide on Remedial Actions at Superfund Sites With PCB Contamination Office of Emergency and Remedial Response Hazardous Site Control Division (OS-220) Quick Reference Fact Sheet GOALS This fact sheet summarizes pertinent considerations in the development, evaluation, and selection of remedial actions at Superfund sites with PCB contamination. It provides a general framework for determining cleanup levels, identifying treatment options, and assessing necessary management controls for residuals. It is not a strict "recipe" for taking action at PCB-contaminated sites, but it should be used as a guide for developing remedial actions for PCBs. Site-specific conditions may warrant departures from this basic framework. A more detailed discussion of these issues can be found in th eGuidance on Remedial Actions for Superfund Sites with PCB Contamination, OSWER Directive No. 9355.4 -01. SUPERFUND GOAL AND EXPECTATIONS The Superfund program goal and expectations for remedial actions (40CFR 300.430 (a)(l)(i) and (iii)( 1990)) should be considered during the process of developing remedial alternatives. EPA's goal is to select remedies that are protec-tive of human health and the environment, that maintain protection over time, and that minimize untreated waste. The Agency expects to develop appropriate remedial alternatives that: Use treatment to address the principal threats at a site, wherever practicable Use engineering controls, such as containment, for waste that poses a rela- tively low long-term threat or where treatment is impracticable Use a combination of treatment and containment to achieve protection of human health and the environment as appropriate Use institutional controls to supplement engineering controls for long-term management and to mitigate short-term impacts Consider the use of innovative tech-nology when such technology offers the potential for comparable or superior treatment performance or implementability, fewer or lesser adverse impacts than other available approaches, or lower costs for similar levels of performance than more demonstrated technologies Return usable ground waters to their beneficial uses wherever practicable, within a timeframe that is reasonable, given the particular circumstances of the site The following sections are organized to follow the Superfund decision process from scoping through preparation of the ROD DETERMINE DATA NEEDS - Consider Special Characteristics of PCBs Considerations to note during scoping and when developing potential remedial alternatives for PCBs, include the following: Applicable or relevant and appropriate requirements (ARARs) for PCBs are relatively complexbecause PCBs are addressed by both TSCA and RCRA (and in some cases, state regulations). Figure 1 illustrates primary regulatory requirements that address PCBs. PCBs encompass a class of chlorin ated compounds that includes up to 209 variations or congeners with different physical and chemical characteristics. PCBs were commonly used as mixtures called Aroclors. The most common Aroclors are Aroclor-1254, Aroclor-1260, and Aroclor-1242. PCBs alone are not usually very mobile. However, they are often found with oils, which may carry the PCBs in a separate phase. PCBs may also be carried with sod particulates to which they are sorbed. Although most PCBs are not very volatile, they are very toxic in the vapor phase. Consequently, air sampling and analytical methodologies should be selected that will allow for detection of low levels of PCBs. Certain remedial technologies will require specific evaluations and/or treatability studies. If biotreatment is considered, the mobility and toxicity of possible by-products should be assessed. If stabilization is considered, the volatilization of PCBs during and after the process should be evaluated. Also, the long-term effectiveness of stabilization should be evaluated carefully. If incineration is considered, the presence of volatile metals should be addressed. Word-searchable version Not a true copy ------- Figure 1 - Primary Regulatory Requirements/Policies Addressing PCBs RCRA Outlines ctosura requirements lor hazardous waste landfills (40 CFR 264.310) Establishes land disposal restrictions for liquid hazardous waste that contains PCBs at 50 ppm or greater or nonliquid hazardous waste that contains total HOCs (including PCBs) at concen- trations greater than 1,000 ppm (40 CFR 268.32) Provides for a treatability variance (40 CFR 268.44) that may be used for PCBs in CERCLA soil and debris. (Under Superfund treatability variance guidance, PCB concentrations should be reduced to .1 -10 ppm for initial concentra- tions up to 100 ppm; above100 ppm, treatment should achieve 90-99% reduction of PCBs, con- sistent with Superfund expectations for treatment.) TSCA Regulates PCBs at concentrations of 50 ppm or greater (40 CFR 761 )* - PCB management options include: incineration (40 CFR 761.70), high- temperature boiler (40 CFR 761.60), alternative technology that achieves a level of performance equivalent to incineration (40 CFR 761.60), and chemical waste landfill (40 CFR 761.75) Note: Liquid PCBs at concentrations of 500 ppm or greater can only be incinerated or treated by using an alternative technology equivalent to in- cineration (40 CFR 761.60). Dredged material may also be disposed of by a method approved by the RA (40 CFR 761.60 (a)(5)). Establishes a PCB spill policy (40 CFR 761.120) that defines the level of cleanup for recent small- volume spills. The Superfund approach is consistent with this policy. CERCLA/NCP Remedial Actions Must: Protect human health and the environment (121[b][1J) Comply with applicable or relevant and appropriate requirements (ARARs) (121[d][2]) Be cost-effective (40 CFR 300.430) (121 [b][1 ]) Utilize permanent solutions and alternative treatment technologies or resource recovery technologies to the maximum extent practicable (40 CFR 300.430) (121[b][1]) CWA Establishes requirements and discharge limits for activities that affect surface water - WQC for PCBs, chronic exposure through drinking water and fish ingestion ป 7.9 x 10 s ppb based on incremental increase cancer risk of 10"* over lifetime - WQC for PCBs, acute toxicity to freshwater aquatic life ฆ 2 ppb, chronic - .014 ppb - WQC for PCBs, acute toxicity to saltwater aquatic life ฆ 10 ppb, chronic - .03 ppb L SDWA Establishes MCLs and MCLGs for drinking water (40 CFR 141) - Proposed MCL for PCBs - .5 ppb MCLG for PCBs ซ 0 ppb * Under the TSCA anti-dilution provision (40 CFR 761.1 [b]), PCBs disposed of after 1978 are treated as if they were at their original concentration. However, the Agency has clarified that the anti-dilution provision is only applicable to Superfund response actions for disposal that occurs as part of the remedial action. Therefore, PCBs at Superfund sites should be evaluated based on the concentration at which they exist in the environment at the time a response action is determined (July 1990 memorandum from Don Clay and Linda Fisher). ESTABLISH PRELIMINARY REMEDIATION GOALS The following guidelines should be con- sidered when establishing preliminary remediation goals (i.e., cleanup levels) for soils, ground water, and sediment. Exceeding the levels indicated does not require that action be taken. These levels should be. used to define the area over which some action should be considered once it has been determined that action is necessary to protect human health and the environment These goals may be refined throughout the RI/FS process; final remediation goals are determined in the remedy selection. Soils The concentration of concern for PCBs (that defines the area to be addressed for soils onsite) will depend primarily on the type of exposure that will occur based on land use-current and future residential or industrial. Guidelines based on generic exposure assumptions and characteristics of Aroclor-1254 are provided in Table 1. Other factors that may affect these levels include the potential for PCBs to migrate to groundwater and to affect environmental receptors. Word-searchable version Not a true copy ------- Table 1 Recommended Soil Action Levels- Analytical Starting Point Land Use Concentration (ppm) Residential 1 Industrial 10-25 The 1 ppm starting point for sites in residential areas reflects a protective quantifiable concentration. (Also, be-cause of the persistence and pervasive-ness of PCBs, PCBs will be present in background samples at many sites.) For sites in industrial areas, action levels generally should be established within the range of 10 to 25 ppm. The appropriate concentration within the range will depend on site-specific factors that affect the exposure assumptions. For example, at sites where exposures will be very limited or where soil is already covered with concrete, PCB concentrations near the high end of the 10-to- 25 ppm range may be protective of human health and the environment. Ground Water If ground water that is, or may be, used for drinking water has been contaminated by PCBs,response actions that return the ground water to drinkable levels should be considered. Non-zero maximum contaminant level goals (MCLG) or maximum contaminant levels (MCL) should be attained in ground water where relevant and appropriate. State drinking water standards may also be potential ARARs. Proposed non-zero MCLGs and proposed MCLs may be considered for contaminated ground water. The pro- posed MCL for PCBs is .5 ppb. Since PCBs are relatively immobile, their presence in the ground water may have been facilitated by solvents (e.g., oils) or by movement on colloidal particles. Thus, the effectiveness of PCB removal from ground water, i.e., ground- water extraction, may be limited. In some cases, an ARAR waiver for the ground water may be supported based on the technical im- practicability of reducing PCB concentrations to health-based levels in the ground water. Access restrictions to prevent the use of contaminated ground water and containment measures to pre- vent contamination of clean ground water should be considered in these cases. Sediment The cleanup level established for PCB- contaminated sediment may be based on direct-contact threats (if the surface water is used for swimming) or on exposure as- sumptions specific to the site (e.g., drink- ing water supplies). More often, the impact of PCBs on aquatic life and consumers of aquatic life will determine the cleanup level. Interim sediment quality criteria (SQC) have been developed for several non- ionic organic chemicals, in- eluding PCBs and may be considered in establishing remediation goals for PCB- contaminated sediments. The method used to estimate these values is called the equilibrium partitioning approach. It is based on the assumptions that: (1) the biologically available dissolved concen- tration of a chemical in interstitial water is controlled by partitioning between sediment and waterphases that can be estimated based on organic carbon parti- tion coefficients; (2) the toxicity of a chemical to, and bioaccumulation by, benthic organisms is correlated with the bioavailable concentration of the chemi- cal in pore water; and (3) the ambient aquatic life water quality criteria (WQC) concentrations are appropriate for the protection of benthic communities and their uses. Table 2 presents the sediment quality criteria and derived PCB sediment concentrations based on the SQC for freshwater and saltwater environments and two organic carbon (OC) concentrations. These criteria are to be considered in establishing remediation goals for con- taminated sediments. Table 2 - Sediment Cleanup Levels Aquatic Environment Freshwater Saltwater Sediment Quality Criteria (SQC) 19 33 (Concentrations expressed as ug/g of sediment) OCs10% 1.90 3.30 OC = 1% 0.19 0.33 DEVELOP REMEDIAL ALTERNATIVES The potential response options at any site range from cleaning up the site to levels that would allow it to be used without restrictions to closing the site with full containment of the wastes. Figure 2 illustrates the process for developing alternatives for a PCB- contaminated site. Primary Alternatives It is the expectation of the Superfund program that the primary alternatives for a site will involve treatment of the principal threats and containment of the remaining low level material. For residential sites, principal threats will generally include soils contaminated at concentrations greater than 100 ppm PCBs. For industrial sites, principal threats will include soils contaminated at concentrations greater than or equal to 500 ppm PCBs. Treatment Options Liquid and highly concentrated PCBs constituting the principal threats at the site should be addressed through treatment. Treatment options that are currently available or are being tested include incineration, solvent washing, KPEG (chemical dechlorination), biological treatment, and solidification. Compliance with TSCA ARARs requires that PCBs, at greater than 50ppm, be incinerated, treated by an equivalent method, or disposed of in a chemical waste landfill. Equivalence to incineration is demonstrated when treatment residues contain <2 ppm PCB. If treatment is not equivalent to incineration, compliance with TSCA ARARs must be achieved by implementing long-term management controls consistent with the chemical waste landfill requirements. (Liquid PCBs at concentrations greater than 500 ppm cannot be landfilled under TSCA.) Containment of Low-Threat Material Long-term management controls should generally be implemented for treatment residuals and other low level contaminated materials remaining at the site. Example scenarios for the use of long-term management controls appropriate for particular PCB concentrations are shown in Table 3. The substantive requirements of a chemical waste landfill specified in TSCA regulations (761.75 Word-searchable version Not a true copy ------- (b)) are indicated, along with the justification that should be provided when a specific requirement is waived under TSCA (761.75 (c)(4) (Under CERCLA on-site actions must meet substantive, but not procedural, requirements of other laws.) TSCA requires that PCBs that are not incinerated or treated by an equiv lent method be disposed of in a chemical waste landfill; it may be appropriate to waive certain landfill requirements, where treatment has reduced the threat posed by the material remaining at the site, as is indicated in Table-3. Exceptions Treatment of low-threat material may be warranted at sites involving: Relatively small volumes of contaminated material Sensitive environments (e.g., wetlands) Floodplains or other conditions that make containment unreliable. In these cases, long-term management controls may be reduced, as shown in Table 3, since the concentrations are lower. Containment of principal threats may be warranted at sites involving: Large volumes of contaminated material for which treatment may not be practicable PCBs mixed with other contaminants that make treatment impracticable Highly concentrated PCBs that are difficult to treat because of their inaccessibility (i.e.,buried in a landfill) Figure 2 - Key Steps In the Development of Remedial Alternatives for PCB-Contaminated Superfund Sites * What Is the action area assuming unlimited exposure? r < > 1 ppm PCB or greater greater > s W.". VX- A Key It fll Residential Industrial xxx Containment O Action Area Boundary ^ \ ^ y J&. What are principal threats to be treated? (PCBs at 500 ppm or greater, or more than 2 orders of magnitude above the action level.) Treat principal threats at least to levels that are to be contained (90-99% Reduction) 10 - 500 ppm 500 ppm or greater 10 - 500 ppm greater Exceptions: | J Large municipal landfills ป; 4 * Inaccessible contamination | ฆNXs -V How should material remaining at the site be contained? Contain residues and remaining material (See Table 3) iSSSAiil Ss ^ s, \>s i" ง- Partially Treat i Treat to levels requiring fewer t I Tr8at to lev8,s ,or which no I :ฆ! long-term management controls \ I long-term management controls { (See TaWe 3) p*i (including acoess restrictions) are | _ j i necessary f " ^ ^ * s t or greater * *sr- P T., ~~ 1 Exceptions: i Small volumes I Sensitive exposures i Unreliable containment * - \ Isฎ*? Fully "Treat j | I j Treat to levels for which no ฆ ' i long-term management oonl I itltlilf I I -J 10-50 ppm 10-500ppm , j j necessary "These numbers are guidance only and should not be treated as regulations. Word-searchable version Not a true copy ------- SELECTION OF REMEDY Criteria and Balancing The analysis of remedial alternatives for PCB-contaminated Superfund sites is developed on the basis of the following nine evaluation criteria provided in the NCP (300.430[e][a] [iii] ;30 0.430 [f] [i] [i]). Considerations unique to PCBs are noted Threshold Criteria * Overall protection of human health and the environment. Are all pertinent exposure pathways being addressed? Are highly concentrated PCBs being treated? Are remaining PCBs and treatment residuals being properly contained, as outlined in Table 3? ~ Compliance with ARARs. Does the action involve disposal of PCBs at con- centrations greater than or equal to 50 ppm? Is the action consistent with TSCA treatment requirements? Is the action consistent with chemical waste landfill requirements, with appropriate TSCA waivers specified for landfilling of material that doesnot meet treatment re- quirements? Is a RCRA hazardous waste present? Do California List land dis- posal restrictions (LDRs) apply? Is the action consistent with LDRs or treat-ability variance levels where appropriate? Is contaminated ground water that is potentially drinkable being returned to drinkable levels or is support for a technical impracticability waiver provided? Balancing Criteria ~ Long-term effectiveness and perm- anence. Are highly concentrated PCBs Table 3 - Selection of Long-Term Management Controls To Be Considered for PCB-Contaminated Sites LONG-TERM MANAGEMENT CONTROLS RECCOMENDEO EMiCAL WASTE ILL REQUIREMENT1 being treated? Are low-concentration PCBs being properly contained, as out- lined in Table 3? Is the site in a location that geographically limits the long-term reliablility of containment (e.g., high water table, floodplain)? ~ Reduction of toxicity, mobility, or volume through treatment. Is there a high degree of certainty that the treat- ment methods selected will achieve at least a 90 percent reduction of PCBs? Does treatment increase the volume of PCB-contaminated material thatmust be addressed either directly (e.g., solidifi- cation) or through the creation of addi- tional waste streams (e.g., solvent wash- ing)? ~ Short-term effectiveness. Istheshort- term inhalation risk resulting from vola- tilization ofthe PCBs properly addressed? What is the relative timing of the differ- ent remedial alternatives? ~ Implementability. Does the treatment selected require construction ofasystem onsite (e.g., KPEG, solvent washing)? Doesthe action require extensive study to determine effectiveness (e.g., biore- mediation)? Are permitted facilities available for Alternatives involving off- site treatment or disposal? Modifying Criteria ~ State acceptance ~ Community acceptance Likely Tradeoffs Among Alternatives Primary tradeoffs for PCB-contaminated sites will derive from the type of treat- ment selected for the principal threats and the determination ofwhatmaterialcanbe reliably contained. Alternatives that require minimal long-term management will often provide less short-term effectiveness and implementability be- cause large volumes of contaminated material must be excavated and treated. They will generally be more costly but will provide highlong-term effective-ness and permanence and achieve significant reductions in toxicity andvolumethrough treatment. Alternatives that involve containment of large portions of the contaminated site will generally have lower long-term effectiveness and per- manence and achieve less toxicity or volume reduction through treatment. However, they will generally be less costly, more easily implemented, andhave higher short-term effectiveness. DOCUMENTATION A ROD for a PCB-contaminated Super- fund site should include the following components under the Description of Alternatives section: Remediation goals defined in the FSfor each alternative, i.e., concentrations above whichPCB-contaminatedmate rial will be addressed and concentrations above which material will be treated. Treatment levels to which the selected action will reduce PCBs before redepos- iting residuals. The consistency of these levels with TSCA requirements and other ARARs should be indicated. Long-term management controls that will be implementedto contain or limit access to PCBs remaining onsite. The consistency with RCRA closure and TSCA chemical waste landfill requirements (and justification for appropriate TSCA waivers) should be indicated. NOTICE Development ofthis document was fundedby the United States Environmental Protection Agency. It has been subjected to the Agency's review process and approved for publication as an EPA document. The policies and procedures set out in this document are intended solely for the guidance of response personnel. They are not intended nor can they be relied upon, to create any rights, substantive or procedural, enforceable by any party in litigation with the United States. EPA officials may decide to follow this guidance, or to act at variance with these policies and procedures based on an analysis of specific site circumstances, and to change them at any time without public notice. Word-searchable version - Not a true copy ------- |