Ala. Code § 22-25-14
It shall be unlawful for any person, firm, corporation, municipal corporation, or other governmental subdivision or agency operating a water treatment plant, water distribution system, wastewater treatment plant, or public wastewater collection system to operate same unless the competency of the operator to operate the plant or system is duly certified to by the director under the provisions of this chapter. It shall also be unlawful for any person, except a trainee as defined in Section 22-25-1, to perform the duties of an operator without being duly certified under the provisions of this chapter. The provisions of this chapter, however, shall not be applicable to the owner or operator of a water treatment plant, water distribution system, wastewater treatment plant or public wastewater collection system that does not offer service to the public generally.
Ala. Code § 22-25-14 (1975)