The amount of the engineer's estimate of the cost of said improvements (exclusive of engineering, fiscal, legal, interest, easement acquisition, and miscellaneous costs) is $1,947,000.00. E & A Consulting Group, and must be accompanied by an original bid bond or a certified check in the amount not less than $97,350.00 made payable to the Treasurer of Sanitary and Improvement District No. 599 as security that the bidder to whom the contract may be awarded will enter into a contract to build the improvements in accordance with this Notice to Contractor and will give a contract and maintenance bond in the amount of 100% of the total contract price, all as provided in the specifications. Bid bonds must be executed by a duly licensed corporate surety. Checks accompanying proposals not accepted shall be returned to the bidders. No bidder may withdraw his proposal for a period of sixty (60) days after date set for opening of bids. The work to be performed in this improvement shall consist of the installation of an 8" diameter PVC sanitary sewer pipe or other approved materials, together with manholes, structures, necessary appurtenances and other items of work incidental and necessary for a completed project; the installation of a storm sewer system of reinforced concrete pipe or other approved materials, together with manholes, structures, necessary appurtenances and other work that is incidental and necessary for a completed improvement; construction of a system of paved public roads and streets of varying widths with Portland cement concrete or other approved materials with a minimum varying thickness of nine inches together with integral curb and gutter, necessary removals, grading, drainage inlets, inlet piping, storm manholes, street signs and necessary appurtenances for a completed project. The successful bidder shall cooperate with the engineer in scheduling its work, and shall submit its schedule to the engineer for approval before commencing work.