Senior Airman Brad Stevens, a 36th Civil Engineer Squadron water and fuels systems journeyman, performs a fire hydrant flow test April 30, 2015, at Andersen Air Force Base, Guam. Water and fuels systems maintainers also repair, maintain or replace washers, valve seats, leaking faucets, and interior or exterior water and sewer lines. (U.S. Air Force photo/Airman 1st Class Joshua Smoot)