There are numerous reasons to decommission abandoned water wells on your property including protection of groundwater resources and the safety of your family. Decommissioning a well properly seals off the well to prevent contaminants from entering the water supply.
General steps to decommission a bored water well.
- Disinfect water with a shock chlorination.
- Slowly pour bags of bentonite into the well, pouring enough for a one-foot-thick layer of bentonite.
- Backfill well with clean sand or gravel, to within ten feet of the surface. Excavate ten feet and remove the casing. Call Sask Power before digging!
- Additional Bentonite seals should be placed between zones. This will be specific to each well.
- Pour enough bags of bentonite for a one-foot-thick layer to seal the top. This layer of bentonite should extend a foot beyond the edges of the removed casing.
- The top ten feet should be filled in with clean clay and tamped down every foot.
- Backfill over the edge of the well hole and mound up one to two feet to allow for drainage and setting.
Picture: Water Security Agency
Complete details on how to properly decommission a large diameter well can be obtained from the Water Security Agency. Small diameter drilled wells need to be decommissioned by a registered well driller.