66-1515. Tank, defined.
Tank shall mean any one or a combination of stationary aboveground or underground containers and enclosures, including structures and appurtenances connected to them, that is or has been used to contain or dispense petroleum, but tank shall not include any pipeline facilities, including gathering lines, regulated under the Natural Gas Pipeline Safety Act of 1968, 49 U.S.C. chapter 24, or the Hazardous Liquid Pipeline Safety Act of 1979, 49 U.S.C. chapter 29, as in effect on January 1, 1988, or any lease production tank used in the production of crude oils.
Source