Ga. Code § 8-3-107
If the area of operation of a regional housing authority consists of an even number of counties, the commissioners of the regional housing authority appointed by the governing bodies of such counties shall appoint one additional commissioner whose term of office shall be as provided in Code Section 8-3-108 for a commissioner of a regional housing authority. The commissioners of such authority appointed by the governing bodies of such counties shall likewise appoint each person to succeed such additional commissioner, provided that the term of office of such person begins during the terms of office of the commissioners appointing him. A certificate of the appointment of any such additional commissioner of such regional housing authority shall be filed with the other records of the regional housing authority and shall be conclusive evidence of the due and proper appointment of such additional commissioner.
OCGA § 8-3-107