These industries employed an estimated 2,575 people. Most of the businesses in Hamilton County purchase their water from a PWS or obtain their water from a private supply not requiring a permit. There is one water use permit for industry in Hamilton County. There is no power production in Hamilton County. Mining Water Use Mining in Hamilton County consists of sand and gravel extraction.
Activity varies from year to year based upon construction needs.
Eight 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 15.3 percent of water samples 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.