The industries employed an estimated 656 people. Most of the businesses in Madison County purchase their water from a PWS or obtain their water from a private supply not requiring a permit. There are no water use permits for industry in Madison County. There is no power production in Madison County. Mining Water Use Mining in Madison County consists of sand and gravel extraction.
Activity varies from year to year based upon construction needs.
Nine water permits were issued for mining in the county. The Iowa State-Wide Rural Well Water Survey, 1990. The UHL's test results for the county also show that in an average year 33.2 percent of wells tested for nitrates exceeded the recommended maximum. These test results are based on non-random samples. The University of Iowa Hygienic Laboratory, Private Well Water Quality, 1990-1994.