Bond, with sufficient sureties, in such amount as shall be deemed adequate, not only to insure performance of contract in the time and manner prescribed in the contract, but also to save, indemnify, and keep harmless the municipality against all loss, damages, claims, liabilities, judgments, costs, and expenses which may in anywise accrue against the municipality in consequence of the granting of the contract, or which may in anywise result therefrom, may be required of each bidder upon contracts involving amounts in excess of $10,000 when, in the opinion of the purchasing agent, the public interests will be served thereby.
65 ILCS 5/8-10-13