The Sandstone and Dolomite Aquifer

The sandstone and dolomite aquifer exists throughout most of the stateWisconsin except for an area in the northwest. This formation has the following characteristics:

• It was formed about 600 million years ago
• It exists below the Maquoketa shale on the eastern side of the State and below the sand and gravel formations
• It is capable of producing substantial amounts of water
• It is the principal bedrock aquifer for wells in the southern and western areas of the state