In this chapter:
(1) “Combined system” means any combination of one or more of the following:
(A) an electric system;
(B) a water system;
(C) a sewer system;
(D) a solid waste disposal system;
(E) a drainage utility system; and
(F) a natural gas system.
(2) “Public security” has the meaning assigned by § 1201.002.
(3) “Utility system” means an electric, water, sewer, solid waste disposal, drainage utility, or natural gas system. The term includes one or more combined systems.