Well

Many homeowners use private wells for irrigation or backup water systems. Danger arises if these wells are physically connected to the treated drinking water system.

Well water contaminants can occur naturally or through human and animal activities. Antifreeze and other automotive fluids, animal waste, septic tanks, detergents, and pesticides are all potential contaminants.

If the pressure in the public water system drops and the pressure from the wells is greater, backflow might occur. Should this happen, the untested and untreated well water could pose a serious hazard to the public supply.