Also consider contamination sources on adjacent properties. Well Construction Properly designed and constructed wells minimize the risk of pollution by sealing the well from anything that might enter it from the surface. Well construction information may be available from the driller, the previous owner, or the well construction report. Five items dealing with well construction deserve detailed consideration. Casing and the well cap.
Casing is a steel or plastic pipe installed during construction to prevent collapse of the borehole.
The space between the casing and sides of the hole should be sealed with grout to prevent pollutant seepage into the well. Visually inspect the well casing with a flashlight for holes or cracks at the surface or down inside. Well cap should be firmly installed with a screened vent. Casing depth and height. The wells should be cased below the water levels in the well to afford greater protection from contamination.