Occurrence of Ground Waters of Low Hardness and of High Chloride Content in Lyon County, Minnesota

The ground water in Lyon County and elsewhere in southwestern Minnesota is generally hard and low in chloride. It is the purpose of this report to describe briefly the occurrence in Lyon County (pi. 1) of waters of low hardness and of high chloride content. The waters are found largely in Cretaceous sandstone. The data were collected in conjunction with a countywide study of the geology and groundwater resources that is being made as part of a statewide investigation in cooperation with the Division of Waters, Minnesota Department of Conservation. The work is under the direct supervision of the junior author, who is district geologist for Minnesota. Hardness and chloride determinations were made with field-testing kits at the time data were obtained on most of the farm wells in the county. Tests were made on wells that were reported to yield relatively soft or "salty" water.