This helps eliminate the problem of obtaining an adequate seal. If the casing cannot be removed, two options are available. One is to excavate a space around the old casing at least 10 feet deep and pour an approved grouting material into the excavation. The second option, shown in Figure 2, is to extend the plug beyond the edges of the original bore hole at least 1 feet beyond the casing. This mushroom plug will prevent water movement along the outside of the casing.
Deeper excavation is desirable when no grouting exists outside the casing.
If these abandoned water wells are not properly sealed, they can provide a direct conduit for surface water carrying pollutants to groundwater. Proper plugging of water wells restores barriers to contamination, removes physical hazards by closing off tempting openings for curious children and animals, and removes liability while improving and protecting property values. This worksheet is designed to accompany the Well Plugging Fact Sheet .