Well Abandonment and Plugging Procedures
Domain 5 covers the legal and technical steps for permanently taking a well out of service. Abandonment is not simply pulling the pump and walking away.
When plugging is required
A well that is no longer used, is not maintained, or poses a threat to groundwater must be plugged. Ohio law requires the work to be done by a licensed driller and reported to the DWR.
Procedure
Remove the pump, wiring, and obstructions. Disinfect the well. Fill the entire borehole with an approved impermeable grout-cement, bentonite, or cement-bentonite-placed from the bottom up. Remove or perforate the casing where required so the plug bonds with the formation. Cut off the casing below grade, seal the top, and restore the site.
Flowing wells
Artesian or flowing wells need a controlled, permanent seal; a shallow plug can be blown out by pressure.
Worked example
A 150-ft well with steel casing is abandoned. The driller removes the pump, disinfects, tremies cement-bentonite to the bottom, cuts the casing 2 ft below grade, welds a cap, and files the plugging report. Filling with sand or gravel would leave a vertical pathway for contamination.
Traps
Using sand, gravel, or drill cuttings as fill; leaving the casing open at the surface; failing to report; and plugging only the top of a deep well are all mark-losing errors.