Four fresh water pumps are used to draw water from the Euphrates River, to supply the US Marine Corps (USMC) Reverse Osmosis Water Purification Units (ROWPU) operated by Marines of the 6th Engineer Support Battalion, (ESB) 1ST Force Support Group, 1ST Marine Expeditionary Force, at a Tactical Water Distribution System (TWDS), located at the Logistics Support Area, Camp Viper, Iraq, during Operation IRAQI FREEDOM