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Hazardous Waste Management Unit: Tank

Hazardous Waste Management Unit: Tank

Pursuant to 40 CFR 262.34, a large or small quantity generator of hazardous waste (LQG or SQG, respectively) may treat or store (ie. accumulate) hazardous waste on-site without a permit in any of four hazardous waste management units:

  • Containers
  • Tanks
  • Drip Pads
  • Containment Buildings

The purpose of this article is to identify and explain what the RCRA regulations refer to as a tank for the accumulation of hazardous waste at an LQG or SQG.

First of all, a tank is only one of several different kinds of Hazardous Waste Management Units, though only the above four are allowed at an LQG or SQG without a permit:

(§260.10) Hazardous waste management unit is a contiguous area of land on or in which hazardous waste is placed, or the largest area in which there is significant likelihood of mixing hazardous waste constituents in the same area. Examples of hazardous waste management units include a surface impoundment, a waste pile, a land treatment area, a landfill cell, an incinerator, a tank and its associated piping and underlying containment system and a container storage area. A container alone does not constitute a unit; the unit includes containers and the land or pad upon which they are placed.

A tank is also defined at §260.10:

Tank means a stationary device, designed to contain an accumulation of hazardous waste which is constructed primarily of non-earthen materials (e.g., wood, concrete, steel, plastic) which provide structural support.

So, a tank must be:

  • Stationary (this distinguishes tanks from containers, which are defined as “any portable device”),
  • Designed to contain hazardous waste (this must be certified by a qualified Professional Engineer), and;
  • Constructed of man-made materials, not dirt as in the case of a surface impoundment.

A tank may be:

  • Above Ground:

(§260.10) Above ground tank means a device meeting the definition of “tank” in § 260.10 and that is situated in such a way that the entire surface area of the tank is completely above the plane of the adjacent surrounding surface and the entire surface area of the tank (including the tank bottom) is able to be visually inspected.

  • Underground:

(§260.10) Underground tank means a device meeting the definition of “tank” in § 260.10 whose entire surface area is totally below the surface of and covered by the ground.

  • Inground:

(§260.10) Inground tank means a device meeting the definition of “tank” in § 260.10 whereby a portion of the tank wall is situated to any degree within the ground, thereby preventing visual inspection of that external surface area of the tank that is in the ground.

  • On Ground:

(§260.10) On ground tank means a device meeting the definition of “tank” in § 260.10 and that is situated in such a way that the bottom of the tank is on the same level as the adjacent surrounding surface so that the external tank bottom cannot be visually inspected.

A “tank” may not look like a tank in the traditional sense; that is, a sump which is essentially a man-made reservoir built into the ground and designed to capture waste from troughs or trenches, can qualify as a tank.

(§260.10) Sump means any pit or reservoir that meets the definition of tank and those troughs/trenches connected to it that serve to collect hazardous waste for transport to hazardous waste storage, treatment, or disposal facilities; except that as used in the landfill, surface impoundment, and waste pile rules, “sump” means any lined pit or reservoir that serves to collect liquids drained from a leachate collection and removal system or leak detection system for subsequent removal from the system.

A generator that accumulates hazardous waste in a tank must comply with the applicable regulations of 40 CFR 265, Subpart J – Tank Systems.  Note that Subpart J refers to the “Tank System” and not just the tank.

(§260.10) Tank system means a hazardous waste storage or treatment tank and its associated ancillary equipment and containment system.

So, a tank system includes the following:

  • The tank, and;
  • Its ancillary equipment, and;
  • The tank’s containment system.

(§260.10) Ancillary equipment means any device including, but not limited to, such devices as piping, fittings, flanges, valves, and pumps, that is used to distribute, meter, or control the flow of hazardous waste from its point of generation to a storage or treatment tank(s), between hazardous waste storage and treatment tanks to a point of disposal onsite, or to a point of shipment for disposal off-site.

A containment system must be:

  • Designed, installed, and operated to prevent a release of waste or other liquids from the tank system into the environment (eg. soil, ground water, or surface water).


  • Capable of detecting and containing a release of waste from the tank or ancillary equipment until it can be removed.

The applicability of Subpart J regulations will depend upon a facility’s hazardous waste generator status:

  • An LQG must comply with all of Subpart J except:
    •  §265.197(c) – closure plan, cost estimates, and financial assurance.
    • And §265.200 – Waste analysis and trial tests.
  • An SQG need only comply with §265.201 of Subpart J – Special requirements for generators of between 100 and 1,000 kg/mo that accumulate hazardous waste in tanks.

The requirements of Subpart J for an LQG will vary depending on the date the tank was put into service:

  • “Existing” tanks were in service or installation commenced prior to or on July 14, 1986.
  • “New” tanks were not put into service until after July 14, 1986.  “New” tanks includes “existing” tanks that had been removed from service and then brought back into service after this date.

If you accumulate hazardous waste in a tank, you must address the tank-specific regulations in your Hazardous Waste Personnel training.  Please contact me for a free training consultation.