Abandonment of an unused well poses a threat to the safety and quality of Wisconsin groundwater supplies. The abandoned water well provides a direct way for contaminants and pollutants to enter the underground
aquifers that supply other working wells.
All Water wells must be correctly filled when they are abandoned or removed from service. Since 1936, the State of Wisconsin has required that unused wells be properly sealed with approved materials and that
the person who sealed the well submit a report to the state describing how the well was filled and sealed. Since June 2008 only a licensed well drilling company is legally allowed to fill and seal an
abandoned water well in Wisconsin.
A well or drill hole is permanently abandoned when it has been completely filled and sealed by a licensed well driller using materials and methods as prescribed by the Wisconsin Administrative Code. This means
that the pump and any piping inside of the casing has been removed and the well has been filled from bottom to top with proper filling materials, such as cement grout, concrete grout, concrete, a
clay/sand slurry mix or in some cases, bentonite chips.
