Staff Sgt. John Matlock, 36th Medical Operations Squadron Bioenvironmental Flight bioenvironmental engineering technician, tests a water sample for chlorine and pH levels on Andersen Air Force Base, Guam, July 2, 2013. The flight takes monthly samples from various locations on base to ensure the water supply remains safe to use. (U.S. Air Force photo by Airman 1st Class Mariah Haddenham/Released)
Staff Sgt. John Matlock, 36th Medical Operations Squadron Bioenvironmental Flight bioenvironmental engineering technician, tests a water sample for bacteria on Andersen Air Force Base, Guam, July 2, 2013. The flight takes monthly samples from various locations on base to ensure the water supply remains safe to use. (U.S. Air Force photo by Airman 1st Class Mariah Haddenham/Released)
Staff Sgt. Jeremy Boldt, 36th Medical Operations Squadron Bioenvironmental Flight bioenvironmental engineering technician, checks the Wet-Bulb Globe Temperature reading on Andersen Air Force Base, Guam, July 2, 2013. Airmen from the bioenvironmental flight monitor the WBGT every two hours, which is a combined reading of radiant heat, ambient heat and humidity, to help determine the heat stress indicator level of the base. (U.S. Air Force photo by Airman 1st Class Mariah Haddenham/Released)
Staff Sgt. John Matlock, 36th Medical Operations Squadron Bioenvironmental Flight bioenvironmental engineering technician, helps Capt. Dennis Trutwin, 736th Security Forces Squadron commander, prepare for a gas mask fit test on Andersen Air Force Base, Guam, July 3, 2013. The flight conducts approximately 100 of these evaluations per month to test how well a mask will protect its wearer from chemical or biological warfare agents in the event of an attack. (U.S. Air Force photo by Airman 1st Class Mariah Haddenham/Released)
Staff Sgt. Jeremy Boldt, 36th Medical Operations Squadron Bioenvironmental Flight bioenvironmental engineering technician, administers a gas mask fit test to Capt. Dennis Trutwin, 736th Security Forces Squadron commander, on Andersen Air Force Base, Guam, July 2, 2013. The flight conducts approximately 100 of these evaluations per month to test how well a mask will protect its wearer from chemical or biological warfare agents in the event of an attack. (U.S. Air Force photo by Airman 1st Class Mariah Haddenham/Released)