Arsenic is a naturally occurring contaminant found in many ground water supplies. It has been detected in both public and private water supplies throughout the U.S., including Arizona, Maine, Michigan and New Mexico. In some cases, the levels being detected exceed the EPA's recommended maximum contaminant level (MCL) of 10 parts per billion (0.010 mg/L).
Because contaminants such as arsenic can be present in well water without leaving any identifying taste or odor, it is important that homeowners have their private well water supplies tested regularly for this impurity as well as any others of regional concern. Check with your local or state health department to see if an arsenic test kit may be available for purchase. Many health departments also offer limited testing for other impurities, including bacteria and nitrates. If your local health department doesn't offer these services, ask them if they can provide you with a list of the independent drinking water laboratories that are approved by your state to offer water testing services to residents.
For further information about arsenic in water, download NSF's Arsenic Fact Sheet. A list of systems that are certified to reduce arsenic is available through NSF's contaminant guide.
If you haven't had your well water tested recently, take advantage of National Drinking Water Week and have it tested now.
