Water on earth today has been here for millions of years. As water evaporates, it travels into the air and becomes part of a cloud. It returns to the earth in the form of precipitation, then it evaporates again.
Some public utilities get water from surface water sources such as lakes and rivers.
Other utilities get water from groundwater sources, where the underground rock, clay, sand and gravel materials form a natural storage area called an aquifer. Utilities that don't have access to a water source have to bring water through pipes for many miles. Tennessee-American has access to an unlimited supply of water from the Tennessee River. The company delivers an average of 38 million gallons of clean, pure water. Even deep groundwater sources can be polluted from the surface.