(a) The governing body of each district shall consist of not less than five supervisors. Two supervisors shall be appointed by the commission, provided that in those districts which contain three or more counties or portions of three or more counties, the commission shall appoint one supervisor for each county in the district. Appointments by the commission shall be made from a list submitted to the commission by the elected supervisors of the district, containing three nominees for each appointive position. The supervisors appointed by the commission shall be persons who are qualified by training and experience to perform the specialized, skilled services which will be required of them in the performance of their duties under this article. Appointed supervisors shall serve for terms of office of two years and until their successors are appointed.

(b) Elected supervisors shall be elected upon a county basis, as provided in Code Section 2-6-30. Not more than one elected supervisor shall be elected from each county within a district, except in districts consisting of less than three counties.