Underground storage tank or “UST” means any one or combination of tanks (including underground pipes connected thereto) that is used to contain an accumulation of regulated substances, and the volume of which (including the volume of underground pipes connected thereto) is 10 percent or more beneath the surface of the ground. This term does not include any:
Underground tank means a device meeting the definition of tank whose entire surface area is totally below the surface of and covered by the ground.
Storage tank means an aboveground storage tank or underground storage tank as defined by this Regulation.
Controlled substance analog means a substance the chemical structure of which is substantially
commercial air transport means an aircraft operation involving the transport of passengers, cargo, or mail for remuneration or hire.
Septic tank means a water tight tank designed to receive sewage and to effect the adequate decomposition of organic matter in sewage by bacterial action;