For the purposes of this article, the following terms shall have the meanings respectively ascribed to them in this section:
(1) MUNICIPALITY. A municipal corporation organized and existing under the laws of Alabama.
(2) WATER SYSTEM. Facilities for the gathering, collecting, impounding, treatment, transmission, and distribution, or any of them, of water for domestic use or for industrial use, or both, together with all appurtenances to any such facilities.
(3) SANITARY SEWER SYSTEM. Facilities for the collection, transmission, treatment, and disposal of sewage, together with all appurtenances to any such facilities.
(4) COMBINED SYSTEM. A consolidated system resulting from the combination of any water system and sanitary system.
(5) SYSTEM. A water system, a sanitary system, or a combined system.