Frequent Questions

Why is it that environmental media and debris contaminated with petroleum product released from an underground storage tank (UST) is not regulated as a hazardous waste but the same materials are subjected to hazardous waste regulations if the petroleum pr

The reason for the different regulatory requirements is that the EPA created a specific hazardous waste exemption for the petroleum-contaminated media and debris caused by leaking USTs because of potentially significant impacts related to the Agency's comprehensive program to prevent leaking underground storage tanks, under Subtitle I of RCRA, including impacts to the cleanup of USTs that have leaked in the past.

Petroleum contaminated media and debris is excluded from the definition of hazardous waste when the media or debris, such as soil and groundwater, is generated from petroleum UST corrective action activities and fails the toxicity characteristic for hazardous waste codes D018 through D043 (§261.4(b)(10)). At the time of promulgation of the final Toxicity Characteristic (TC) rule, EPA made a determination to temporarily defer applicability of the TC rule to media and debris contaminated with petroleum from USTs subject to the corrective action requirements of Subtitle I of RCRA. EPA had little information regarding the full impact of the TC rule on UST cleanups; however a preliminary assessment indicated that the number of UST cleanup sites and the amount of media and debris at each site that would exhibit the toxicity characteristic would be extremely high. EPA reasoned that subjecting all, or even a portion, of these sites to Subtitle C requirements could overwhelm the hazardous waste permitting program and the capacity of existing hazardous waste treatment, storage, and disposal facilities. In addition, imposition of the requirements could delay UST cleanups significantly (58 FR 8504, 8504; February 12, 1993). 

On December 24, 1992, EPA proposed a similar exclusion for contaminated media and debris contaminated by petroleum products from non-UST sources (57 FR 61542), however, EPA never finalized that proporal.  EPA later stated in the HWIR-media proposal that finalization was unnecessary because a final HWIR-media rule would solve the problems that the non-UST TC suspension was intended to address (63 FR 65873, 65931; November 30, 1998).
It is important to note that a generator must still determine if petroleum contaminated media and debris is hazardous for the hazardous waste codes D001 through D017 (Memo, Lowrance to Bevington; November 9, 1990 (RCRA Online #11569)). In addition, the definition of an UST includes those tanks or combinations of tanks whose volume, including the volume of underground connected piping, is ten percent or more beneath the surface of the ground (§280.12). Any tank that does not meet this definition is not a UST for the purposes of Part 280, would not be subject to comprehensive requirements for the reporting and cleanup of soil and groundwater contaminated from USTs, and thus would not qualify for the exclusion in §261.4(b)(10). 

The February 12, 1993 Federal Register (58 FR 8504) is available at the following URL:

The November 30, 1999 Federal Register (63 FR 65873) is available at the following URL: 

Additional guidance regarding the petroleum contaminated media and debris exclusion in §261.4(b)(10) is available in the following documents:
Monthly Call Center Report Question; January 1998 (RCRA Online #14316
Monthly Call Center Report Question; November 1994 (RCRA Online #13711
Monthly Call Center Report Question; October 1990 (RCRA Online #13409)

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