Nubian Sandstone Aquifer System

The Nubian Sandstone Aquifer System (NSAS) is the world's largest known fossil water aquifer system. It is located underground in the Eastern end of the Sahara desert and spans the political boundaries of four countries in north-eastern Africa.^[1] NSAS covers a land area spanning just over two million km², including north-western Sudan, north-eastern Chad, south-eastern Libya, and most of Egypt. Containing an estimated 150,000 km³ of groundwater,^[2] the significance of the NSAS as a potential water resource for future development programs in these countries is large. The Great Man-Made River (GMMR) project in Libya makes use of the system, extracting substantial amounts of water from this aquifer, removing an estimated 2.4 km³ of fresh water for consumption and agriculture per year.^{[citation needed]}