(1) All operators of water and wastewater systems are encouraged to become certified, although this part requires only that a person in direct charge of a water treatment plant, wastewater treatment plant, water distribution system or wastewater collection system be certified.
(2) There is nothing in the part to prohibit a single person becoming a certified operator for more than one (1) of the functions listed in subsection (a).
(3) It is permissible for one (1) certified operator to have the responsibility for more than one (1) water and/or wastewater system where two (2) or more systems are involved in reasonable proximity to one another, and where the duties of operation are such that the work time of one (1) person may properly be divided among two (2) or more systems, or where a certified operator may adequately supervise the work of others in more than one (1) system.