O.C.G.A. § 50-8-64

Each commission shall develop a system for competitive bidding relating to the purchase of supplies, equipment, and services and the letting of other contracts and submit written procedures governing such systems to the board of directors of the commission and to the commissioner. Such procedures must accommodate any applicable fund source requirements relating to procurement and must provide, at a minimum, that contracts let out for bid shall be awarded to the lowest responsible bidder.