How Often Should You Test Your Well for Water Safety

The United States has one of the world’s safest water supplies, but occasionally contaminants can enter an aquifer or well. The contaminants can be naturally occurring, such as radon or arsenic, or have a man-made source, such as pesticides or sewage.

More than 15 million Americans get their water from a private well, but they are not regulated by the Environmental Protection Agency, so it is important for homeowners to monitor their water supply if it comes from a well.

What Are Some Of The Well Water Contamination Problems?

  • Radon is a colorless, odorless, tasteless, naturally occurring radioactive gas found in rocks and soil around the world. Radon dissolves into ground water and is released later in the home during everyday tasks like showering and washing dishes. When radon is released into the home, it can accumulate and increase risk of disease, particularly lung cancer.

  • Bedrock wells in New Hampshire have about a one in five chance of containing at least a small amount of naturally occurring arsenic. Studies have shown that repeatedly drinking water with arsenic during a person’s lifetime can lead to cancer and other chronic ailments, such as cardiovascular or neurological disorders. 

  • Nitrate is naturally found in many types of food and is safe in small doses, however, high levels of nitrate in drinking water can make people sick. Nitrate can leach into your well from flooded sewers, private septic systems and other agricultural runoff. The presence of nitrate in your well also depends on the geology of the land in your surrounding area.

  • Volatile organic compounds is the name for industrial chemicals that can be harmful to your health. These compounds can come from manufacturing plants or fuel storage areas and your risk for contamination is dependent on where you live. One contaminant, MTBE, was once found in gasoline in New Hampshire and Massachusetts and its subsequent contamination of soils near gas stations resulted in multiple lawsuits.

  • Contamination from other sources depends on the location of your well and if you live in a rural or urban area. Some of these include lead, mercury, radium and pesticides.


The Centers for Disease Control and Prevention recommend checking your well every spring for mechanical problems and testing for contaminants once a year. Some people opt to have their well tested when they first buy a home and then never test again.

Others test regularly for peace of mind. There are certain times, however, when every homeowner should test the property’s well. This includes when other people in your areas have experienced well water problems, if there has been flooding or a major disturbance near the well, if your home is near a waste disposal site, if you have recently replaced any part of your well system, or if you notice a change in the water quality.


The annual test recommended by the EPA includes looking for the following:

  • Coliform bacteria: A high amount of this microbe indicates that harmful germs like viruses, bacteria and parasites might also be found in the water.
  • Nitrates
  • Total dissolved solids
  • pH level

You should also consider testing for contaminants that may affect you area. You state environmental department can help you determine what contaminants pose a risk.


State and local health or environmental departments, including New Hampshire and Massachusetts, test for most of the common contaminants. These agencies can also refer you to certified laboratories. Skillings & Sons works with certified laboratories and can help you determine what contaminants you should test for, as well as conducting the test.

Skillings & Sons, Inc. will provide you with a water testing kit. Just stop by our location or contact us for more information.

Click here to learn more about water testing and download our water testing guide.