Digging a new well? Plug the old one
Karen Mancl
  
Many of us remember Jessica McClure, from Midland, Texas. In 1987, as a small child, she fell down a 10-inch diameter abandoned well. Her rescue was national news.

As more and more homes are built in rural Ohio,  more wells are being drilled. In Ohio, more than 1 million homes are served by private wells. While drilling a new well, take time to find and properly seal old wells to avoid safety problems and groundwater contamination.

Wells are direct pipelines to the groundwater. They are constructed bring clean water to the surface. But if they are not maintained and protected, these same wells can carry contamination down into the groundwater. Clean and dirty water can flow both ways.

Abandoned wells threaten groundwater
One of the biggest threats to Ohio's groundwater is old, abandoned wells. It is the landowner's responsibility to plug abandoned wells to eliminate safety and pollution problems. To plug a well, firt remove all equipment, like the pump and pipes.

If possible, remove the well casing, liners and screen. If that is too difficult be sure to slit or perforate the casing to allow for a good seal. If the casing cannot be pulled, dig down at least 4 feet and cut it off below ground level.

The well should then be filled from the bottom up to the top with bentonite clay. To do this properly, a tube is sent all the way down to the bottom of the well and the clay slurry is pumped into the well. The tube is slowly lifted up to the top, filling the entire well with bentonite.

Get professional help
Contact a well driller and make sure they have the equipment and experience sealing wells with bentonite. To find out more about sealing abandoned wells, check with the Ohio Department of Natural Resources, Division of Water. You can check their Website at: http://www.dnr.ohio.gov/water, where they have posted fact sheets on wells and lists of Ohio well drillers.

To learn more about well water testing and treatment, also check the website for Ohio State Soil Environment Technology learning Lab: http://stll.osu.edu

 

Karen Mancl, professor and Extension Water Quality Specialist, can be reached at 614-292-6007 or mancl.1@osu.edu 

 

This column is provided by the OSU Department of Food, Agricultural, and Biological Engineering http://fabe.osu.edu