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Module 9 — Plugging Abandoned Wells
Who is Responsible?
In Alberta, responsibility for plugging a water well is defined by legislation. The well
owner is responsible for plugging the well when:
The well is no longer being used as a water supply
The well is in a poor state of repair and the pumping equipment has been removed
or cannot be repaired or replaced
The well produces water that is unsuitable for drinking.
The licensed water well contractor is legally responsible for immediately plugging a well
when it is not completed due to construction problems or inadequate yield. Before you sign a
contract with a driller, ask questions about what materials are going to be used to plug the
well and associated costs.
It is generally best to hire a licensed water well contractor to complete the plugging of
your well. This person has the expertise and equipment to do a proper job. Unless you use
the right plugging materials and have them properly placed in the well, you will end up with
a poorly sealed well that will continue to allow contaminants to enter into the groundwater.
When a replacement well is drilled, your old well should be immediately plugged.
Process of Plugging a Well
There are several steps to take before actually plugging the well. Some steps you will be
able to do yourself and others you may want to consult with, or hire, a licensed water well
contractor to complete.
Preparation
To know exactly how much plugging material is needed, measure the total depth and
diameter of the well, plus the non-pumping water level (the depth to the standing water in
the well). If possible, compare these measurements to the information on the drilling report
from when the well was originally constructed. The only time you should even consider
plugging a well yourself is when the well is open to its original depth.
Ideally the casing should be removed from the well before the plugging process begins.
Often only the liner casing is removed and the surface casing is left intact because it is more
difficult to remove and it could separate down hole. The older the well, the more difficult it
will be to successfully remove the casing. If the casing is left in place, it should be perforated,
particularly if there is evidence of water movement in the annulus of the well. Any casing left
in place must be cut off 0.5 m (20 in.) below ground surface after the well is plugged.
For information on how to take a non-
pumping water level measurement, see
Module 5 "Monitoring Your Water Well".