(a) Notwithstanding any provision of paragraph (1) of subsection (a) of Code Section 46-5-134 to the contrary, where two or more counties, none of which offers emergency 9-1-1 system services on May 1, 1998, and any participating municipalities within such counties, if any, agree by intergovernmental contract to initiate or contract for the joint operation of an emergency 9-1-1 system for the first time after May 1, 1998, such local governments may impose a monthly 9-1-1 charge which exceeds $1.50 per telephone service but only so long as the following procedure shall be followed:

(1) The participating local governments shall, with input from a telephone service supplier, prepare an estimated budget for the implementation of the joint emergency 9-1-1 system with costs limited to items eligible for funding through the Emergency Telephone System Fund;

(2) An estimate of the revenue to be generated by the 9-1-1 charge authorized by paragraph (1) of subsection (a) of Code Section 46-5-134 during the first 18 months of collection shall be prepared;

(3) If the total amount necessary for implementation of the emergency 9-1-1 system in paragraph (1) of this subsection exceeds the estimated revenue from imposition of the 9-1-1 charge specified in paragraph (2) of this subsection, the monthly 9-1-1 charge per telephone service may be increased on a pro rata basis during the first 18 months of collection to the extent necessary to provide revenue sufficient to pay the amount specified in paragraph (1) of this subsection, but in no case shall such monthly charge be greater than $2.50 per telephone service. Notwithstanding subsection (i) of Code Section 46-5-134, if each local governing body which is a party to an intergovernmental contract certifies to the service provider in writing prior to the end of the 18 month period in advance of the date on which the 9-1-1 system was to have become fully operational that the system cannot be placed in operation on the date originally projected but that all parties are proceeding in a diligent and timely fashion to implement such service, the service provider shall continue to collect the monthly 9-1-1 charge for an additional period of 18 months or until the 9-1-1 system becomes fully operational, whichever occurs first; and

(4) Such local governments shall comply with the requirements of Code Section 46-5-133 which relate to the imposition of a monthly 9-1-1 charge.

Nothing in this subsection shall be construed to authorize the imposition of any charge upon a wireless service. Except as otherwise provided in this subsection, the requirements of Code Section 46-5-134 which relate to monthly 9-1-1 charges on telephone services shall apply to charges imposed pursuant to this subsection.

(b) The increased monthly 9-1-1 charge authorized by subsection (a) of this Code section shall also be available to any joint 9-1-1 authority created pursuant to Code Section 46-5-138 after May 1, 1998.