U.S. Air Force Staff Sgt. Phillip Coley, 20th Civil Engineer Squadron water and fuels systems maintenance craftsman, completes inspects the cathodic protection inside of a water tower at Shaw Air Force Base, S.C., July 8, 2014. Cathodic protection controls the metal corrosion of the 250,000 gallon water tower. (U.S. Air Force photo by Airman 1st Class Jensen Stidham/Released)