This article will explain where your drinking water comes from and define the two types of water systems. Surface water consists of lakes, reservoirs, and rivers. The large-scale water supply companies tend to rely on surface water to serve their customers. According the U.S. Geological Survey's 1996 National Water Summary, approximately 47 percent of the population use surface water for their source of water.
Ground water is found in the pores and cavities of rocks beneath the earth's surface.
The water must be pumped out of wells. The depth of the wells depends on its location. Some may be as shallow as 50 feet or deeper than 1,000 feet. According to the U.S. Geological Survey's 1986 National Water Summary, approximately 53 percent of the population uses ground water for their source of water. A public water system provides water to at least 25 people for at least 60 days annually.