U.S. Army Corps of Engineers Pittsburgh District contractors finish up concrete work on a major project at the Monongahela River Locks and Dam 4 in Charleroi, Pennsylvania, May 30, 2023. The Pittsburgh District has refilled the newly constructed lock chamber with 18 million gallons of water and has entered the final construction phase. Next, the district will install miter gates and test the mechanical and electric locking components. The district expects the new lock to go into operation in 2024. The construction project at Charleroi is part of the Lower Mon Project, sometimes referred to as a "mega project" because of its size and scope. (U.S. Army Corps of Engineers Pittsburgh District Photos by Michel Sauret)