(a) In any county in which a system of emergency medical services has been established before July 20, 1979, the quorum court of the county may levy service charges on residents of the county or designated area of the county in which services are provided to finance or assist in financing the services.
(b) The ordinance levying service charges to finance emergency medical services programs established before July 20, 1979, shall be subject to the same notice and hearing requirements and shall be subject to referendum in the same manner as is provided in this subchapter for the ordinance establishing a system of emergency medical services.