"Pool" means an underground reservoir containing a common accumulation of crude petroleum oil or natural gas, or both. Each zone of a general structure which is completely separated from any other zone in the structure is covered by the term "pool" as used [...]

"pool" means any structure, chamber, or tank containing an artificial body of water used by the public for swimming, diving, wading, recreation, or therapy, together with buildings, appurtenances, and equipment used in connection with the body of water, [...]