How often should I test my private well water?

More detail

Over 15 million U.S. households use private wells. Because the Safe Drinking Water Act does not apply to them, state and federal agencies do not monitor their safety. The homeowner is the sole quality controller.

In addition to the annual basics, you should test every three years for local geological contaminants like radon or uranium. You should also test if a pregnant person moves in, if an infant is drinking formula made with well water, or if there is nearby agricultural flooding.

Always use a state-certified (ELAP/NELAP) laboratory. Store-bought test strips are not sensitive enough to detect harmful levels of bacteria or heavy metals.