Geophysical Logging Conducted for Chicago Flood Control Project

Thornton quarry and interstate 80.The Illinois State Geological Survey (ISGS) provided borehole geophysical logging in support of the Transitional Flood Control Reservoir. The goal for this study for the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) is to identify fractures, bedding planes, and other features in order to implement a concrete curtain around the quarry. Part of the project requires pumping water into the holes in order to log the entire formation with acoustic imaging. The ISGS is currently coordinating with Raimonde Drilling and with the geologists and engineers with Black & Veatch and Arcadis. So far, five core holes have been logged, three of which were drilled at 15 degrees, and two of which are vertical. Three additional holes will be logged in the near future. Average depths are ~ 550 feet deep, and the holes are concentrated around the perimeter north lobe of Thornton Quarry. Logs that were recorded include gamma, 8-inch, 16-inch, 32-inch, 64-inch normal resistivity, spontaneous potential, single-point resistance, spinner/flowmeter, fluid temperature and resistivity, and acoustic televiewer.