The provisions of the plumbing code, as adopted in subsection 10-1-1A of this title, shall apply to all structures and premises located within the city, and to all structures and premises and persons, firms and corporations outside the limits of the city if the same is connected or to be connected, directly or indirectly, to any sewer emptying, directly or indirectly, into the sewer system or to the water system of city. (1991 Code § 4-39)