The Idaho Transportation Department (ITD) selected Collins to provide underwater inspections of 28 local agency bridges and 39 state bridges over a period of one year.
The work primarily consisted of performing underwater inspections of local, off-system, and on-system bridges at the frequencies defined in the Idaho Manual for Bridge Evaluation.
The scope included providing detailed inspection reports for 67 structures as well as a routine inspection for the Egin Canal structure in St. Anthony, and a detailed substructure evaluation and report of the Blue Creek Bay structures on I-90.
The Blue Creek Bay evaluation included underwater ultrasonic thickness measurements and electric corrosion potential measurements of the substructure. The inspection used surface-supplied air diving techniques and underwater photography.