I believe this project is subject to Iowa state law that would obligate them to select the lowest responsible bidder. However, the apparent low contractor is a very reputable, local firm that has done dozens and dozens, probably hundreds of projects around the area, including countless jobs on the U of I campus. There are no worries about the "low bidder" in this case, IMO.
6 General Contractors submitted bids, I would describe the bidding as pretty competitive. #1 left about 3/4 Mil on the table though, but it was very tight after that for spots #2 thru #5, with those only being separated by roughly the same margin as between #1 and #2, about $880K.
#1 $21.372MM
#2 $22.107MM
#3 $22.544MM
#4 $22.608MM
#5 $22.990MM
#6 $24.233MM