Staff Sgt. Dallas English, 28th Logistics Readiness Squadron fuels laboratory NCO in-charge, places a water detection pad into an Aqua-Glo Water Detector during a fuel sample test inside the fuels lab at Ellsworth Air Force Base, S.D., March 26, 2013. Sodium fluorescence is used to detect the presence of water, which turns neon green under a black light. (U.S. Air Force photo by Airman 1st Class Anania Tekurio/Released)