Airman 1st Class Joseph Brown, 1st Special Operations Medical Support Squadron bioenvironmental engineer technician, observes a test tube full of pool water for pH and chlorine levels at the Aquatic Center on Hurlburt Field, Fla., July 22, 2015. As one of their many proficiencies, bioenvironmental engineering is responsible for ensuring water conditions are safe for all personnel at Hurlburt Field. (U.S. Air Force photo/Senior Airman Meagan Schutter)