CTLGroup was retained by the City of Evanston to inspect and evaluate the original 1913 portion of the water treatment facility in Evanston, Illinois. The facility included six filter tanks, two below-grade filtered water reservoirs, a pipe gallery, and dehumidification equipment room. CTLGroup reviewed available documents and conducted field investigations, which included visual inspection, hammer sounding, and nondestructive testing. Concrete core samples were also extracted and compressive strength tests, chloride tests, and petrographic examinations were conducted to evaluate condition. Findings from the investigation were presented in a report along with repair recommendations and budgetary repair cost estimates.
CTLGroup was later retained to inspect and evaluate a finished water reservoir and two settling basins at the water treatment facility. The finished water reservoir was located under a parking lot and significant evidence of extensive freeze-thaw damage was discovered in the concrete roof slab. Based on the observed deterioration, CTLGroup recommended replacement of the roof slab and annual inspections of the roof slab until repair measures could be implemented.