A water supply may be obtained from three formations: the Drift, Pierre shale and Dakota sandstone. The shallow waters of the Drift are the more satisfactory and may be reached at a depth of 40‑50 feet. Water is often found in the coulees and in the gravel morainal areas. Water in small quantities and varying in quality may be obtained in the sandy layer of the Pierre shale and in the friable white Dakota sandstone. There are a few artesian wells, which vary in depth from 80‑110 feet. They also vary in quality of water and as a rule are located in the northwest part of the county. In 1959 Eugene Zink, a farmer near Bordulac dug an artesian well at a depth of 1,849 feet where he hit water under internal pressure. The driller used mud and water in the process, checked the various strata through which the drill penetrated, and upon reaching 1849 feet he decided to make a test because the sand appeared right for a good vein. First all of the mud had to be pumped out and when that was completed, the flow of water began. The water was soft and palatable and was at first used in the feed yard but was later also piped into the house. It ran at a rate of seven gallons per minute. After this success several other wells were dug in the county.
Source: A History of Foster County 1983 Page 19