The casing in your water well supports the wall of the well so that loose rock, soil sand, and gravel which the well shaft has penetrated doesn't collapse into the well. The casing also protects the electrical wiring, pull cable for the pump and water tubing and pi[ping that is connected to the submersible pump.
The casing also provides a vertical-cylindrical surface that along with the outer vertical wall facilitates the placement of a grout seal around the well casing. This seal prevents surface water and other contaminants like fertilizers, pesticides, and bacteria from entering the well.
Steel water well casings have been the material of choice for the last century. Today, improvements in the strength, durability and corrosion resistance of polyvinyl chloride (PVC) over the past two decades have made PVC casing a common material choice for drinking water wells.
