Georgia Code Title 42. Penal Institutions § 42-4-103

(a) Failure of a participant county or participant municipality to execute an operation and finance agreement duly adopted by the authority at a regularly scheduled meeting or a meeting called for that purpose within 60 days after such agreement has been executed by two or more participant counties or participant municipalities shall constitute a withdrawal from the authority.

(b) Any participant county or participant municipality may withdraw from the authority subject to any contract, obligation, or agreement with the authority, but no participant county or participant municipality shall be permitted to withdraw from any authority after any obligation has been incurred by the authority. The governing body of the participant county or participant municipality wishing to withdraw from an existing authority shall signify its desire by resolution or ordinance.