Frequent Questions

Would secondary containment be required for a rail car containing used oil while it is at a transfer facility for 3 days?

Any container or tank used to store used oil at a transfer facility for greater than 24 hours, including used oil contained in a rail car, must be equipped with secondary containment (40 CFR Section 279.45). The secondary containment system should include dikes, berms, or retaining walls and a floor at a minimum, although other equivalent secondary containment systems may be used (Sections 279.45(d)-(e)). The storage areas around containers and aboveground tanks must be equipped with oil-impervious floors and secondary containment structures, such as retaining walls or dikes and berms used in conjunction, capable of containing all potential spills and releases of used oil until the discovery and cleanup of spills and releases (57 FR 41566, 41590; September 10, 1992).  An aboveground storage tank system consisting of a shop-fabricated double-walled tank operated with overfill prevention measures may also provide equivalent protection (57 FR 41566, 41591; September 10, 1992). 

Regardless of how secondary containment is achieved, the entire containment system must be sufficiently impervious to used oil to prevent any leakage of oil within the containment system from migrating out to soil, groundwater, or surface water prior to the cleanup of spills and releases. The secondary containment requirements apply to all used oil transfer facilities (i.e., those facilities that temporarily store used oil for longer than 24 hours but not exceeding 35 days) regardless of their location and regardless of the size of any single tank or container at the facility or the total storage capacity of the facility (57 FR 41566, 41590; September 10, 1992). The secondary containment requirements do not apply to aboveground tanks or containers taken out of service at a transfer facility. However, any material left in these out-of- service units must be handled appropriately under all applicable regulations, including RCRA Subtitle C standards if the material meets the definition of hazardous waste. Storage of used oil in tanks or containers over 35 days at a transfer facility would subject the facility to the standards for used oil processors and re-refiners in Part 279, Subpart F (57 FR 41566, 41590-41591; September 10, 1992).

The September 10, 1992, Federal Register (EPA530-Z-92-011) is available at the following URL:

Additional guidance on the secondary containment standards at used oil transfer facilities is available in the following guidance:

Monthly Call Center Report Question; February 2004 (RCRA Online #14702)

This guidance document is available in the RCRA Online database at the following URL:


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