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In the United States, hazardous wastes are subject to regulations mandated by the Resource Conservation and Recovery Act (RCRA). Every month, we provide clear, in-depth guidance on a different aspect of the RCRA regulations. The information presented here is an excerpt from McCoy’s RCRA Unraveled, 2021 Edition.

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Point of Generation for Remediation Wastes

Where is the point of generation (POG) for remediation wastes such as contaminated soil and ground water? The answer is quite complicated, and it depends on three issues: 1) retroactivity of RCRA, 2) “active management,” and 3) movement of wastes within a unit or area of contamination (AOC). These three topics are discussed in the next three subsections.

Retroactivity of RCRA

Do hazardous waste characteristics and/or listings apply today to wastes that were legally disposed before the characteristics and/or listings went into effect? If we disposed some waste in the 1970s that now exhibits a characteristic or meets a listing description, is that disposal site a hazardous waste landfill? Do we have to go back today and excavate that waste and manage it as hazardous? In other words, is RCRA retroactive?

According to EPA, hazardous waste characteristics and listings do apply retroactively to wastes disposed prior to the effective date of the characteristics and listings. The agency first stated its position as follows: “once a particular waste is listed, all wastes meeting that description are hazardous wastes no matter when disposed.” [Emphasis added.] [August 17, 1988; 53 FR 31147; see also May 17, 1988; 53 FR 17586] As such, wastes that were not hazardous at the time of disposal, but which are subsequently identified or listed as hazardous wastes, become hazardous when the new characteristic or listing goes into effect. For example, spent solvents disposed in 1977 may meet the same listing description as spent solvents disposed in 2014. Having said that, such previously disposed waste is not subject to hazardous waste management regulations unless it is “actively managed.”

“Active management”

EPA’s retroactive application of characteristics or listings does not mean that all newly identified or listed wastes must be removed from their historical disposal site for proper treatment. RCRA does not require such retroactive waste management. If no regulatory program (e.g., the RCRA corrective action program) is making you clean up the previously disposed waste, RCRA regulations do not apply to it. Nor does EPA impose any retroactive penalties for prior disposal of the waste, since it was legally disposed at that time. The RCRA regulations kick in only when the wastes are actively managed. Consequently, compliance with the RCRA Subtitle C regulations is not required at the disposal site (whether it is still operating or not) unless the previously disposed wastes are actively managed. [March 8, 1990; 55 FR 8762–3]

EPA has defined “active management” as “physically disturbing the accumulated wastes within a management unit or disposing additional hazardous wastes into existing waste management units containing previously disposed wastes.” [September 1, 1989; 54 FR 36597, August 18, 1992; 57 FR 37298] “Disturbing” a waste includes removing, excavating, mixing with other wastes, or other onsite treatment (including ex situ treatment). [RO 11954, 12995, 13057]

Thus, cleanups involving removal of wastes or contaminated media from a site (e.g., excavating solids or pumping ground water) are deemed to be active management. In these situations, all wastes that exhibit a characteristic or meet a listing description [including environmental media that “contain” listed wastes] must be managed as hazardous wastes, even if they were disposed before the applicable characteristic or listing effective date. Furthermore, any mixtures of those wastes with other solid wastes and wastes derived from the treatment, storage, or disposal of those wastes may be regulated as hazardous via application of the mixture and derived-from rules. Finally, all such wastes that are hazardous because they are being actively managed are subject to the LDR program. [August 17, 1988; 53 FR 31148]

The second part of the active management definition notes that continued use of an existing unit, after the effective date of an applicable hazardous waste identification or listing, for treatment, storage, or disposal of a newly identified or listed waste (or any other hazardous waste), will subject the unit and its contents to RCRA Subtitle C regulation. Conversely, if only nonhazardous waste is added to a waste management unit in which wastes were previously disposed before they were regulated as hazardous, this activity would not constitute active management. Additional retroactivity and active management examples are explored in Case Study 1.

Case Study 1

Exception for plant construction activities

During excavation of soil as part of a plant construction activity, contaminated soil is sometimes unearthed. If the soil exhibits a characteristic or is contaminated with a listed hazardous waste, the soil is a hazardous waste when excavated. This causes a concern since the dirt is often piled up before it is put back in the hole (e.g., when a trench is being dug to lay a pipeline or conduit). Does that make the hazardous soil subject to generator standards? If so, that would also make the piles of dirt Subtitle C waste piles subject to RCRA permitting and Part 264/265, Subpart L standards.

EPA has addressed this issue in guidance by stating that, as long as the hazardous dirt remains in the area of contamination (i.e., the contaminated soil is not moved to an uncontaminated area of the plant or shipped offsite) and is subsequently put back in the ground from which it was excavated, such operations do not produce a hazardous waste or subject it to hazardous waste regulation. Therefore, the dirt would not have to be counted, the piles are not regulated waste piles, and the land disposal restrictions do not apply. [RO 11671] Although this guidance did not specifically say the hazardous soil was never actively managed, the agency noted in EPA/530/K-05/011 (available at that “excavation of contaminated soil during routine construction operations, such as pipeline installation, may not be considered active management if the soil is redeposited into the same excavated area. Site-specific situations should be discussed with the implementing agency.” Thus, EPA has decided to give facilities conducting construction operations relief from managing contaminated soil as hazardous if the soil is returned to the trench. States might not include this federal guidance as part of their state program, so use this with caution.

Leachate derived from previously disposed wastes

The derived-from rule states that residues derived from the treatment, storage, or disposal of a listed hazardous waste remain listed. [§261.3(c)(2)(i)] Based on this rule, hazardous waste listings apply to leachate derived from the disposal of listed hazardous wastes. This holds true for leachate derived from wastes disposed before an applicable listing effective date, even if the landfill ceased disposal of the waste before it became hazardous. If the leachate is actively managed, it is subject to hazardous waste regulation. [May 17, 1988; 53 FR 17586] The point of generation of the hazardous waste is when the leachate is first collected or otherwise actively managed. [August 6, 1998; 63 FR 42191] This interpretation was upheld by the U.S. Court of Appeals for the District of Columbia Circuit in 1989 (Chemical Waste Management, Inc. vs. EPA, 869 F.2d 1526).

Active management of leachate from the pre-1980 disposal of wastes now meeting a listing description does not, by itself, subject landfills holding such wastes to RCRA hazardous waste regulation. Also, the collection of hazardous leachate from an inactive unit does not subject the unit to Subtitle C management. [August 17, 1988; 53 FR 31149, August 6, 1998; 63 FR 42191]

In many situations, active management of leachate is exempt from RCRA Subtitle C regulation because the leachate is managed under the CWA. The leachate is either discharged to a sewer line running to a publicly owned treatment works (POTW) or to a navigable water of the United States under an NPDES permit. Such wastes are excluded from RCRA regulation at the point of discharge under §§261.4(a)(1) and 261.4(a)(2), respectively. Management of leachate in wastewater treatment tanks prior to discharge under the CWA is also exempt from RCRA regulation under the wastewater treatment unit exemption of §§264.1(g)(6) and 265.1(c)(10).

Wastes in surface impoundments

Wastes (particularly sludges) can remain in surface impoundments for a long time. Similar to the situation for landfills discussed above, wastes disposed in the impoundments before becoming listed or identified as hazardous wastes are hazardous today. Still, they do not become subject to RCRA regulation unless the wastes are actively managed. The regulatory status of the wastes and impoundments depends on several factors, as discussed in EPA preamble language and correspondence. [September 27, 1990; 55 FR 39410, November 2, 1990; 55 FR 46383, RO 11826, 13510] Five different scenarios are envisioned for wastes deposited or generated in an impoundment prior to the effective date of their listing or identification:

  1. If the wastes are removed from the unit before the effective date, the wastes and the impoundment are not subject to the hazardous waste regulations (as long as the unit does not receive or generate any hazardous waste after the effective date).
  2. If the wastes remain in the unit (which is considered the final disposal site for the wastes) after the effective date, and the unit does not receive or generate any hazardous waste after the effective date, the hazardous wastes in the impoundment are not being actively managed. Therefore, neither the wastes nor the impoundment become subject to RCRA Subtitle C requirements.
  3. If the wastes remain in the unit (which is not considered the final disposal site for the wastes) after the effective date, and the unit does not receive or generate any hazardous waste after the effective date, the hazardous wastes in the impoundment are being stored (i.e., actively managed). Therefore, the wastes and the impoundment become subject to RCRA Subtitle C requirements on the effective date. This scenario is based on the facility removing some or all of the waste from the unit on a periodic basis on or after the effective date.
  4. If the wastes are removed from the unit after the effective date in a one-time removal as part of a closure, the wastes are subject to hazardous waste management requirements (i.e., they are being actively managed), but the impoundment is not a Subtitle C unit (as long as the unit does not receive or generate any hazardous waste after the effective date). EPA does not consider one-time removal of waste from a unit on or after the effective date, in and of itself, to make the impoundment a storage unit subject to Subtitle C.
  5. If the wastes are scoured from the unit after the effective date (due to nonhazardous wastewater influent) and the unit’s effluent is therefore listed or exhibits a characteristic, the unit generating the hazardous wastewater and any surface impoundment receiving that hazardous effluent would be subject to Subtitle C requirements.

Corrective action and CERCLA provisions still apply

As mentioned above, if units contain characteristic or listed wastes but are not being used for active waste management after the identification or listing effective date, they would not be subject to regulation under Part 264 or 265. However, inactive units located at facilities otherwise subject to Subtitle C interim status or permitting requirements are solid waste management units (SWMUs) subject to corrective active requirements under RCRA Section 3004(u) or 3008(h). In addition, the CERCLA cleanup authorities may also apply. [September 27, 1990; 55 FR 39410]

Movement of wastes within a unit or AOC

With the advent of the LDR program, the POG of remediation wastes became more complicated. When wastes are moved within a RCRA unit (e.g., a landfill), does this constitute waste generation, subjecting the moved waste to LDR treatment standards? EPA’s position on this issue was explained on March 8, 1990 [55 FR 8759]: “EPA believes…that movement of waste within a unit does not constitute ‘land disposal’ for purposes of application of the RCRA LDRs.” Although not specifically stated, the implication is that moving waste within a unit is not considered to be an activity that generates a waste. However, moving a waste outside a unit and placing it in another unit can constitute waste generation: “EPA has consistently interpreted the [term] ‘placement’…to mean the placement of hazardous wastes into [a land disposal unit], not the movement of waste within a unit.” [55 FR 8759]

In remediation settings, EPA considers broad areas of generally dispersed contamination to be essentially the same as a RCRA unit (e.g., a landfill). Under the area of contamination (AOC) policy, wastes can be moved within the AOC without triggering LDR requirements or generating new wastes. When wastes are removed from the AOC, waste generation has occurred, and if the waste is placed in a land disposal unit, the LDR requirements will apply. [RO 14291]

Summary of POG for remediation wastes

In summary, the POG of a remediation waste is when it is actively managed, unless the waste is being moved within a unit or AOC. In this latter case, the POG would be when the waste leaves the unit or AOC.

The following examples illustrate how EPA has interpreted POG issues for remediation wastes.

Soil contaminated by a previous site owner is being cleaned up by the current owner/operator. What is the POG of the soil?

In remediation activities, the POG is the point when/where the contaminated soil is excavated. [May 26, 1998; 63 FR 28617, RO 13748, 14283]

Does simply moving contaminated soil constitute waste generation?

No. “In what is typically referred to as the area of contamination (AOC) policy, EPA interprets RCRA to allow certain discrete areas of generally dispersed contamination to be considered to be RCRA units (usually landfills). Because an AOC is equated to a RCRA land-based unit, consolidation and in situ treatment of hazardous waste within the AOC do not create a new point of hazardous waste generation for purposes of RCRA…. The AOC interpretation may be applied to any hazardous remediation waste (including nonmedia waste) that is in or on the land.” [RO 14291] “Contaminated soil may be consolidated within an area of contamination before it is removed from the land (i.e., generated); the determination as to whether the soil exhibits a characteristic of hazardous waste or contains listed hazardous waste may be made after such consolidation.” [RO 14283; see also RO 14338]


Topic: RCRA/CERCLA Remediation Interface

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This document addresses issues of a general nature related to the federal RCRA regulations. Persons evaluating specific circumstances dealing with the RCRA regulations should review state and local laws and regulations, which may be more stringent than federal requirements. In addition, the assistance of a qualified professional should be enlisted to address any site-specific circumstances.