One of the mission organizations that SAMAIR flies for is Living Water. They drill and install wells in villages where there is no source of clean water. Since many communites are located close to rivers, the villagers are used to bathing, drinking, and washing clothes with the nasty brown river water.
The wells that Living Water puts in are usually about 30 meters deep and pump out clean water, are enclosed so no comtaminates can enter them, use a simple hand pump, and the well heads last for over 20 years with no maintenance. I think this is a great technology as it fills an obvious need for the villages yet is simple and reliable.
I flew in part of a team that came down from the USA to visit and work for a week. It was a wet and rainy day which left tracks in the soft grass runway.