More than 15 million U.S. households depend on private wells for their water supply, according to the Center for Disease Control and Prevention (CDC). It is imperative to keep well water that is consumed by humans and domestic animals free of bacteria and chemicals that can compromise health. While public water supplies are protected by Environmental Protection Agency (EPA) standards and regulations, it is left to private well owners to test their well water's safety for use and to protect the well to prevent water contamination.
Inspect the well casing once a year. Damaged casing allows pollutants to flow into the well and contaminate the water. Look for holes and cracks, and use a light to inspect the inside of the casing. Push on the casing to make sure it's sturdy; if the casing moves, it may be vulnerable to pollutants. Place your ear next to the well casing's opening to listen for running water, which could indicate a crack or hole in the casing.
Test fuel tanks around the home once a year and fix any leaks to prevent fuel from polluting the well water.
Install or have a driller install a watertight cap with a vented screen over the casing's opening. A loose cap or no cap lets pollutants, insects and surface water enter the well. A ventilated cap lets air in while keeping contaminants out.
Install check valves on water faucets with hose connections to prevent backflow, a condition that occurs when water and pollutants flow back from a home's plumbing to the well. Check valves will prevent polluted water in tubs, sinks, washing machines, fire hydrants and swimming pools.
Test well water once a year at an EPA-certified laboratory. Since separate tests for different pollutants can be expensive, test only for chemicals and other contaminants you have in your home, as well as coliform bacteria and nitrate. If underground storage tanks are in the area, test water for volatile organic chemicals (VOCs) at least once a year. Also test for VOCs if and when an oil, petroleum or solvent spill occurs near your well. Test for pesticides if you live near a farm or another area where pesticides are used. Test for water hardness if you notice mineral buildup around your plumbing and fixtures. Test the water again if family members experience gastrointestinal distress you suspect might be related to drinking the water or if you notice a change in the water's taste.
Slope the ground away from the well to allow surface water to drain away properly. This will help prevent surface water from contaminating your well water.
Pump water at a moderate speed to help prevent depletion of groundwater supplies.
Keep contaminants away from the well to prevent contamination by chemicals and bacteria in case of a spill, leak or runoff. The CDC recommends making sure the well is at least 50 feet away from septic tanks, livestock and silos; 100 feet from fuel tanks, manure storage and fertilizer storage, and 250 feet from manure stacks. Also, don't use insecticides, weed killers or fungicides within 100 feet of the well.
Seek advice of a professional well contractor on well-water treatment options such as filtration systems, distillation systems, water softeners and disinfection. Water filtration and distillation systems remove contaminants from well water; water softeners reduce excess minerals that build up on and damage plumbing and fixtures, and disinfection kills harmful microorganisms in well water.
Hire a professional well driller and pump installer to properly close and fill old, unused wells to prevent them from contaminating your well water. Have your well sealed off and a new well drilled if the well reaches the end of its productive service. Most wells should be able to produce for at least 20 years.