The county purchasing department shall perform all acts necessary to purchase or contract for all supplies, materials, equipment, and contractual services required by any or all county offices, departments or agencies. The county board shall select the county offices, departments or agencies to be serviced by the county purchasing department. The board may authorize any county office, department or agency designated by the board to purchase directly, without the intervention of the director of purchasing, certain specified supplies, materials, equipment, or contractual services, and shall designate the manner in which the purchases shall be made.
The county purchasing department also shall perform the following duties:
(1) prepare all specifications for supplies, materials and equipment;
(2) transfer to or between county offices, departments or agencies, or sell supplies, materials, and equipment which is surplus, obsolete, or unused.