The industries employed an estimated 1,516 people. Most of the businesses in Clayton County purchase their water from a PWS or obtain their water from a private supply not requiring a permit. There are two water use permits for industry in Clayton County. There is no power production in Clayton County. Mining Water Use Mining in Clayton County consists of sand and gravel extraction.
Activity varies from year to year based upon construction needs.
Fifteen water permits were issued for mining in the county. The State-Wide Rural Well Water Survey completed in 1989 indicates the following quality results for private well water, shown in Table 3, for the northeast hydrogeologic region in which Clayton County is located. The Iowa State-Wide Rural Well Water Survey, 1990. The UHL's test results for the county also show that in an average year 22.5 percent of wells tested for nitrates exceeded the recommended maximum. These test results are based on non-random samples.