Senior Airman Alexander Delfs, 436th Aerospace Medical Squadron bioenvironmental engineering journeyman, visually inspects a water test sample Nov. 16, 2016, at an aircraft watering point on Dover Air Force Base, Del. Airmen assigned to the 436th AMDS biomedical engineering flight routinely test water pH and chlorine concentration at location. (U.S. Air Force photo by Senior Airman Aaron J. Jenne)