A few nice share photos images I found:
Marines purify water in Africa
Image by United States Marine Corps Official Page
A Marine with 6th Engineer Support Battalion cups purified river water here July 30, 2010. Marines with 6th Engineer Support Battalion are working to purify a local water source for civilian use and mission support as part of exercise SHARED ACCORD 2010. The 10-day exercise, which runs Aug. 3-13, will include staff training, small unit tactical training, and humanitarian civic-assistance programs to include medical services, dental services, and engineering projects.