In early 2016 a Michigan Utility contracted UCC to provide consultation for a planned decommission of a fossil fuel power generation plant. UCC assisted with project planning, construction methodology and system condition assessments to ensure a successful project.
In May of 2016 all eight coal fueled units were taken offline after 76 years of operation and the water infrastructure decommissioning started. UCC was contracted to perform dewatering services and permanent sealing of five separate intake fore bays and tunnels, as well as, five separate discharge tunnels. Following the pre-construction investigations, UCC mobilized a team of divers from the UCC Midwest Division, Michigan office and custom built pumps to dewater and seal the system bays and tunnels.
A significant amount of debris removal was required prior to dewatering the systems. UCC utilized a series of owned and operated dredge pumps and pipelines to perform diver assisted dredging services. Approximately 1,000 cubic yards of material was pumped over 2,300 feet to the site approved disposal area. Once debris removal was completed, system isolation commenced to include gate sealing, gate cover installation, stop log installation, discharge pipe isolation, and plug installations. Custom built inflatable tunnel plugs were provided to be installed prior to dewatering the eight foot diameter discharge tunnels. Once dewatering started, continuous dives were completed to seal additional piping within the 900LF tunnels. Following dewatering, custom forms were erected and a flowable fill was pumped to permanently seal the intake bays, tunnels and discharge tunnel systems.
Each of the unit systems were unique and presented a different challenge. Collaboration and excellent communication from all parties of the decommissioning team resulted in a successful project with zero safety incidents.