Abstract

What is ground water?

Ground water is water stored in pores within soil and rock beneath the land surface. When these pores are connected so that water can be transmitted to wells or springs, these bodies of soil and rock are termed aquifers, from two Greek words meaning "water" and "to bear."

Why is ground water important?

Ground water is the primary source of drinking water for approximately 400,000 residents in Oakland County, Michigan. This drinking water is withdrawn from aquifers by private wells or larger community wells. Approximately 233,000 Oakland County residents use private wells for their household drinking water. More than 160,000 residents are served by over 140 public water suppliers, who provide drinking water for communities ranging from small subdivisions to large municipalities, such as Waterford Township. Over 95 percent of wells in the county draw water from the shallow glacial aquifer.

Ground water that is not withdrawn from the shallow glacial aquifer eventually flows into rivers, lakes, and wetlands in and around Oakland County. Ground water accounts for between 40 and 91 percent of all water in Oakland County rivers. (Holtschlag and Nicholas, 1998). Nearly all of the water in rivers and wetlands during the dry summer months is from ground water. This water provides critical support for fish and other aquatic life. Unfortunately, contamination in ground water can spread into lakes and rivers.

Cleanup of contaminated ground water is an expensive and prolonged process, frequently taking decades. When ground-water supplies become contaminated, the community bears the cost through diminished property values, replacement or expansion of public water supplies, and replacement or abandonment of private domestic wells (Groundwater Education in Michigan, 1998; U.S. Environmental Protection Agency, 2004). The National Research Council (1994) has estimated that ground-water cleanup costs could reach $1 trillion nationwide over the next 20 to 30 years.