65 ILCS 5/9-2-105
Except as otherwise provided in Section 9-2-113, the board of local improvements may reject any and all proposals or bids, should they deem it best for the public good. If the board is of the opinion that a combination exists between contractors, either to limit the number of bidders, or to increase the contract price, and that the lowest bid is made in pursuance thereof, the board shall reject all proposals or bids. The board may reject the bid of any party who has been delinquent or unfaithful in any former contract with the municipality. It shall reject all proposals or bids other than the lowest regular proposals or bids of any responsible bidder and may award the contract for the specified work or improvement to the lowest responsible bidder at the prices named in his bid. Such an award shall be recorded in the record of its proceedings. Such an award, if any, shall be made within 20 days after the time fixed for receiving bids.
If no award is made within that time, another advertisement for proposals or bids for the performance of the work, as in the first instance, shall be made, and thereafter the board shall proceed in the manner above provided in this Division 2. Such a re-advertisement shall be deemed a rejection of all former bids, and thereupon the respective checks and bonds corresponding to the bids so rejected shall be returned to the proper parties. However, the check accompanying any accepted proposal or bid shall be retained in the possession of the president of the board until the contract for doing the work, as hereinafter provided, has been entered into either by the lowest responsible bidder or by the owners of a majority of the frontage, whereupon the certified check shall be returned to the bidder. But if that bidder fails, neglects, or refuses to enter into a contract to perform that work or improvement, as provided in this Division 2, the certified check accompanying his bid and the amount therein mentioned, shall be declared to be forfeited to the municipality, and shall be collected by it and paid into its fund for the repairing and maintenance of like improvements. Any bond forfeited may be prosecuted, and the amount due thereon collected and paid into the same fund.
65 ILCS 5/9-2-105