Subject to the policies and directives of the county board of health and the policies and directives of the multiple county districts served, the director shall perform the functions and exercise the powers set forth in this chapter except the power to adopt bylaws and to adopt rules and regulations and may delegate the powers and authority conferred, or any part thereof, to one or more individuals as he may deem appropriate. The director shall devote his entire time to the service of the county board of health and to the multiple county districts, where created, and shall be vigilant in procuring compliance with its rules and regulations and with Georgia health laws and rules and regulations adopted thereunder that have application within the county and district. He shall make reports to the county board of health and the agency in charge of the multiple county district in such manner and form and with such frequency as required by it and shall also report to the department in such manner, detail, and form as the department may specify.