This project is part of the comprehensive rehabilitation program for the Oakland-Macomb Interceptor Drain (OMID). Under this Contract, executed via a lump sum bid as a General Contract, three cast-in-place control structures were built within a Temporary Earth Retention System (TERS).
Lift Stations Structure No. 6, situated within the International Transmission Co. (ITC) corridor, involved a self-performed two-stage temporary circular earth retention system with diameters ranging from 65 to 72 feet and a depth of 80 feet below grade. The upper part of the TERS was constructed using steel ribs and wood lagging boards, while the lower part consisted of 3-foot diameter cement-stabilized drilled piers with 12-inch cement-stabilized plug piers, extending to 100 feet deep. This structure included a Dewatering/By-Pass Pump Station with four dewatering pumps and a Carbon Odor Control System, supported by a new Outdoor MUCC Center. Grout injection was performed both from the surface and inside the structure.

Structure No. 7 involved self-performed TERS with an internal dimension of 34 feet by 24 feet by 41 feet deep, constructed using 3-foot diameter cement-stabilized drilled piers with 12-inch cement-stabilized plug piers, reaching a depth of 71 feet.

Structure No. 8 involved a TERS with an inside diameter of 24 feet by 30 feet deep, constructed using steel ribs and wood lagging boards.

Once the TERS were complete, cast-in-place access structures were constructed from depths ranging from minus 30 to 80 feet up to grade. Two of these structures used temporary dewatering methods, including deep gravity wells and a series of educator dewatering wells. All three structures entailed excavation, installation of temporary flumes, support rib steels within existing active interceptors, backfill, electrical systems, and site restoration.

Each control structure was equipped with guide rails and grooves for stop gate installation, featuring hydraulic sluice gates and actuators for mechanical operation during flow control management, thereby enhancing the OMID system’s functionality and maintenance.