Staff Sgt. David Ertwine, 628th Civil Engineer Squadron water fuels system maintenance craftsman, secures a harness around his torso for safety before climbing a water tower to check chlorine levels July 29, 2013, at Joint Base Charleston – Air Base, S.C. The water tower is used in emergencies such as destruction from hurricanes or heavy storms. The water‘s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

Staff Sgt. David Ertwine, 628th Civil Engineer Squadron water fuels system maintenance craftsman, secures a harness around his torso for safety before climbing a water tower to check chlorine levels July 29, 2013, at Joint Base Charleston – Air Base, S.C. The water tower is used in emergencies such as destruction from hurricanes or heavy storms. The water‘s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

(Top) Staff Sgt. David Ertwine, and Senior Airman Michael Ang, 628th Civil Engineer Squadron water fuels system maintenance craftsmen, climb a water tower to perform a chlorine test July 29, 2013, at Joint Base Charleston – Air Base, S.C. The water tower is used in emergencies such as destruction from hurricanes or heavy storms. The water’s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

(Top) Staff Sgt. David Ertwine, and Senior Airman Michael Ang, 628th Civil Engineer Squadron water fuels system maintenance craftsmen, climb a water tower to perform a chlorine test July 29, 2013, at Joint Base Charleston – Air Base, S.C. The water tower is used in emergencies such as destruction from hurricanes or heavy storms. The water’s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

Senior Airman Michael Ang, 628th Civil Engineer Squadron water fuels system maintenance craftsman, climbs a water tower to perform a chlorine test July 29, 2013,at Joint Base Charleston – Air Base, S.C. The water tower is used in emergencies such as destruction from hurricanes or heavy storms. The water’s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

Senior Airman Michael Ang, 628th Civil Engineer Squadron water fuels system maintenance craftsman, climbs a water tower to perform a chlorine test July 29, 2013,at Joint Base Charleston – Air Base, S.C. The water tower is used in emergencies such as destruction from hurricanes or heavy storms. The water’s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

(Left) Staff Sgt. David Ertwine, and (right) Senior Airman Michael Ang, 628th Civil Engineer Squadron water fuels system maintenance craftsmen, rest on a walkway near the top of a water tower before making the final climb to the top to perform a chlorine test July 29, 2013, at Joint Base Charleston – Air Base, S.C. The water tower is used in emergencies such as destruction from hurricanes or heavy storms. The water’s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

(Left) Staff Sgt. David Ertwine, and (right) Senior Airman Michael Ang, 628th Civil Engineer Squadron water fuels system maintenance craftsmen, rest on a walkway near the top of a water tower before making the final climb to the top to perform a chlorine test July 29, 2013, at Joint Base Charleston – Air Base, S.C. The water tower is used in emergencies such as destruction from hurricanes or heavy storms. The water’s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

Senior Airman Michael Ang, 628th Civil Engineer Squadron water fuels system maintenance craftsman, climbs a water tower to perform a chlorine test July 29, at Joint Base Charleston – Air Base, S.C. The water tower is used in emergencies such as destruction from hurricanes or heavy storms. The water’s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

Senior Airman Michael Ang, 628th Civil Engineer Squadron water fuels system maintenance craftsman, climbs a water tower to perform a chlorine test July 29, at Joint Base Charleston – Air Base, S.C. The water tower is used in emergencies such as destruction from hurricanes or heavy storms. The water’s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

Staff Sgt. David Ertwine, 628th Civil Engineer Squadron water fuels system maintenance craftsman, performs a chlorine test on a water sample he pulled from a base water tower July 29, 2013, at Joint Base Charleston – Air Base, S.C. The water tower is used in emergencies such as destruction from hurricanes or heavy storms. The water’s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

Staff Sgt. David Ertwine, 628th Civil Engineer Squadron water fuels system maintenance craftsman, performs a chlorine test on a water sample he pulled from a base water tower July 29, 2013, at Joint Base Charleston – Air Base, S.C. The water tower is used in emergencies such as destruction from hurricanes or heavy storms. The water’s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

Senior Airman Michael Ang, 628th Civil Engineer Squadron water fuels system maintenance craftsman, rests at the bottom of a water tower after making the climb to the top and back down to perform a chlorine test July 29, at Joint Base Charleston – Air Base, S.C. The water tower is used for emergencies such as destruction from hurricanes or heavy storms. The water’s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)

Senior Airman Michael Ang, 628th Civil Engineer Squadron water fuels system maintenance craftsman, rests at the bottom of a water tower after making the climb to the top and back down to perform a chlorine test July 29, at Joint Base Charleston – Air Base, S.C. The water tower is used for emergencies such as destruction from hurricanes or heavy storms. The water’s chlorine level was safe for human consumption. (U.S. Air Force photo/ Senior Airman Dennis Sloan)