Spc. Sean Walton, 787 Medical Detatchment, New Orleans, La., tests water from a Reverse Osmosis Water Purification Unit at the Quartermaster Liquid Logistics Exercise, Camp Pendleton, Calif. QLLEX is a joint forces exercise where 64 units at eight locations across the continental United States will deliver more than 3.25 million gallons of petroleum and produce 479,000 gallons of water, designed to challenge and develop the battalion's staff military decision making skills. (US Army photo by Spc. Thomas X. Crough/Released)