What’s that pipe in my backyard?
Abandoned wells pose a great risk to our water supply.
Wells are our source for drinking water. They are drilled into a usable aquifer, a formation from which we get our groundwater, and we pump water up to drink, clean, cook, etc. But wells do fail and we need to drill new ones. What do you do with the old ones?
Today, most well drillers decommission the old wells. But in the past they may have been left open. A cap may have been put on the top of the well but that was about the extent of a well closure. Caps over time may corrode and break or may be taken off and never put back on. Even if there is a cap over an abandoned well the casing of the well may develop holes.
Why should we be concerned?
Wells are direct links to aquifers. When we have a well that is open and not in use we are creating a direct link into that aquifer. Everything that gets into the well itself will go down into the groundwater. If a contaminant is near an open well it may run into the well. Or if the casing is damaged or has a hole in it anything that filters through the surface can migrate into the casing.
Where are abandoned wells?
Abandoned wells are everywhere. A common myth is that they are only on farmland. If you have a pipe sticking out of the ground and you have no idea what it is or where it comes from, it could likely be an abandoned well. You may also have an old dug well on your property. These are extremely dangerous. You have probably heard on the news how children or animals fall into these wells.
What do I do if I have an abandoned well on my property?
If you want to close, or decommission, an abandoned well you should have a licensed well driller do it. Closing a well is not as easy as you may think. Wells are not closed with a simple cement mixture. Cement will crack and then you have the same problem you had in the first place. The substance that is used often to close wells is bentonite. Bentonite is a clay material that swells when it gets wet, filling the spaces in the casing. Bentonite does not get solid so it will not crack. It is slowly poured into the well because small dust particles may bridge causing an incomplete closure. For these reasons it is recommended that a licensed well driller be contracted to close your well.
For more information on well closure or to help determine if you have an abandoned well your local health department sanitarian or your local conservation district. “Plugging Abandoned Wells” is an excellent resource found at the Michigan State University Extension Bookstore.