Underground storage tank systems with field-constructed tanks and airport

hydrant fuel distribution systems definitions. For purposes of this section, the following definitions apply: 1. "Airport hydrant fuel distribution system" (also called airport hydrant system) means an underground storage tank system which fuels aircraft and operates under high pressure with large diameter piping that typically terminates into one or more hydrants (fill stands). The airport hydrant system begins where fuel enters one or more tanks from an external source, such as a pipeline, barge, rail car, or other motor fuel carrier. 2. "Field-constructed tank" means a tank constructed in the field. For example, a tank constructed of concrete that is poured in the field, or a steel or fiberglass tank primarily fabricated in the field is considered field-constructed.