U.S. Geological Survey ground-water studies in Iowa

Ground water is the primary source for most water uses in Iowa. Ground-water resources supply 81 percent of the water withdrawn in Iowa for non-power-generating uses. Ground water from five principal aquifer systems is the source of drinking water for approximately 82 percent of the State's population. These aquifers range from land surface to several thousand feet below land surface. Land use in Iowa is predominately agricultural; about 93 percent of the land is farmed. The major issues related to ground water in Iowa are:

Nonpoint pollution from agricultural chemicals,

Contamination by hazardous wastes, and

Limitations on use owing to quantity or the natural quality.