Airman 1st Class Brandon Lees, 779th Aerospace Medicine Squadron bioenvironmental technician, places a sample in an incubator on Joint Base Andrews, Md., Dec. 6, 2016. The test is incubated for 24 hours to promote growth of any present bacteria. The Airmen perform more than 140 water tests each year and also assess shops for occupational hazards to keep JBA members safe. (U.S. Air Force photo by Senior Airman Mariah Haddenham)