Seal of Dane County County of Dane
Dane County Land & Water Resources Department

Well Decommissioning Program

A look down into an abandonment well

Abandoned or unused wells, if not properly decommissioned or closed, can become a potential liability for landowners and pose a serious safety risk to humans and animals and significant threat to groundwater quality.

Properly decommissioning a well can prevent the possibility of someone or something falling into it. Many older wells can be hidden in vegetation and/or covered by unsecured objects such as old plywood or sheet metal that offer little protection. Wells vary in size but can be found up to 6 feet across and reach 50 feet deep or deeper. These wells can be unsafe and could prove fatal for people, children, pets, or other animals that step or fall into them.

Abandoned wells that have not been properly decommissioned can also provide a direct channel for contaminants to move into groundwater. The contaminants bypass the natural filtration provided by soils and beds of clay, which protect the water quality of groundwater aquifers deep below the Earth's surface. Once contaminants have reached the groundwater it is extremely difficult, and often impossible, to remove them.

Information on testing your well, requirements for decommissioning, and other information is on the Public Health Madison & Dane County website. Dane County staff can provide technical assistance and support to landowners who need to properly decommission wells that are no longer being used. Please contact staff (PDF) to learn more about how our department can assist you through this process.