The Ypsilanti Community Utilities Authority (YCUA) provides water and wastewater services to the Ypsilanti area, processing over eight billion gallons a year. YCUA has an extension system of underground concrete tunnels connecting the various facilities on the property. Recently the tunnels have experience water intrusion at several locations. ISI was contracted to develop the most cost effective and efficient means to prevent future water damage by installing a waterproofing system over the concrete tunnel caps and installing new expansion control systems.