30 ILCS 525/4
The purchases of all personal property, supplies and services under this Act, except for small purchases, shall be based on competitive solicitations unless, for purchases made pursuant to subsection (a) of Section 2 of this Act, it is the determination of the applicable chief procurement officer that it is impractical to obtain competition. Purchases pursuant to this Section shall follow the same procedures used for competitive solicitations made pursuant to the Illinois Procurement Code when the State is a party to the joint purchase. For purchases made pursuant to subsection (a) of Section 2 of this Act where the applicable chief procurement officer makes the determination that it is impractical to obtain competition, purchases shall either follow the same procedure used for sole source procurements in Section 20-25 of the Illinois Procurement Code or the same procedure used for emergency purchases in Section 20-30 of the Illinois Procurement Code. For purchases pursuant to subsection (a) of Section 2, bids and offers shall be solicited by public notice inserted at least once in a newspaper of general circulation in one of the counties where the materials are to be used and at least 5 calendar days before the final date of submitting bids or offers, except as otherwise provided in this Section. Where the State of Illinois is a party to the joint purchase agreement, public notice soliciting the bids or offers shall be published in the appropriate volume of the Illinois Procurement Bulletin. Such notice shall include a general description of the supplies or services to be purchased and shall state where specifications may be obtained and the time and place for the opening of bids and offers. The governmental unit conducting the competitive procurement process may also solicit sealed bids or offers by sending requests by mail to potential contractors and by posting notices on a public bulletin board in its office. Small purchases pursuant to this Section shall follow the same procedure used for small purchases in Section 20-20 of the Illinois Procurement Code.
All purchases, orders or contracts shall be awarded to the lowest responsible bidder or highest-ranked offeror, taking into consideration the qualities of the articles or services supplied, their conformity with the specifications, their suitability to the requirements of the participating governmental units and the delivery terms.
Where the State of Illinois is not a party, all bids or offers may be rejected and new bids or offers solicited if one or more of the participating governmental units believes the public interest may be served thereby. Each bid or offer, with the name of the bidder or offeror, shall be entered on a record, which record with the successful bid or offer, indicated thereon shall, after the award of the purchase or order or contract, be open to public inspection. A copy of all contracts shall be filed with the purchasing office or clerk or secretary of each participating governmental unit.
30 ILCS 525/4