The user charge system shall be reviewed periodically to assure that each user is paying a proportionate share of applicable costs. The service charge for equivalent service units and categories of service shall be adjusted as necessary to reflect costs. Rates and classes of service shall be established by resolution of the assembly, and may be changed at any regularly scheduled meeting of the assembly with prior notice to the service district. [Ord. 82-3-O, 1982. Formerly §13.01.130].