The county purchasing agent, with the assistance of the county purchasing commission, is required to adopt, promulgate, and may from time to time amend rules and regulations for the purchase of supplies, materials, equipment, and contractual services, and specifically for the following purposes, as set out in T.C.A. § 5-14-107:

Emergencies—Authorizing in writing any department, official or agency of the county government to make purchases in the open market for immediate delivery in emergencies; defining such emergencies; and describing the manner in which such emergency purchases shall be made and promptly afterward reported to the county purchasing agent.

Requisitioning, Purchasing, Delivery, Storage, and Distribution— Prescribing the manner in which supplies, materials and equipment shall be requisitioned, purchased, delivered, stored, and distributed; and prescribing the dates for submitting requisitions and estimates, the future period they are to cover, the form in which they are to be submitted, the manner of their authentication, and their revision by the county purchasing agent.

Receiving and Testing of Materials and Equipment—Prescribing the manner of inspecting all deliveries of supplies, materials and equipment, and of making or procuring chemical and physical tests of samples submitted with bids and samples of deliveries to determine compliance with specifications.

Invoice Examination—Prescribing the manner in which invoices for supplies, materials, equipment and contractual services delivered to any and all departments, agencies, and offices of the county shall be submitted, examined, and approved.

Surplus Property—Requiring periodic and special reports by county departments and agencies of stocks of surplus, unusable or obsolete supplies and equipment on hand; providing for transfers of surplus supplies and equipment to and between county departments and agencies which may be surplus to one but needed by another; and providing for the disposal by sale, after receipt of competitive bids, of supplies, materials, and equipment which are obsolete or unusable.

Bonds—Determining whether a deposit or bond is to be submitted with a bid on a purchase contract or sale, and if required, prescribing the amount and form thereof, and providing that such surety shall be forfeited if the successful bidder refuses to enter into contract 10 days after the award.

Public Auctions of County-Owned Property—Prescribing the manner in which public auctions for the sale of county-owned property, real or personal, which has become surplus, obsolete, or unusable shall be conducted.

Other Matters—Providing for all other such matters as may be necessary to give effect to the foregoing rules and to the provisions of this part.