Tracking Groundwater in Maine

In Maine, more than half of all homes rely on private wells for drinking water. Many wells have levels of arsenic, uranium, or other chemicals that can cause serious health effects such as cancer or low birth weight. These contaminants can only be detected through laboratory testing. Private well owners are responsible for testing their own water and correcting any problems.

While everyone who gets drinking water from a private well should regularly test the water, some areas may be at higher risk than others for exposure to harmful chemicals. Updated data available from the Maine Tracking Program is helping identify those higher risk areas and drawing a clearer picture about well water quality across the state.

The Maine Tracking Network data portal displays well water data summarized for several geographic units, including Maine’s towns and counties. Users can now view water quality data for six potentially hazardous substances derived from more than 50,000 well water tests. Their site also includes data about homes with a well and well water testing behavior.

Tracking program staff work continually to increase awareness about the importance of testing private wells, especially in areas at higher risk for exposure. They use the well water data to find the higher risk areas and then develop location-specific messages about water quality and testing behavior.  One example of this is a targeted mailing sent out to parents with young children to promote the need to test well water among private wells in the identified areas, and the distribution of posters to town offices.

Maine is one of 26 CDC-funded local tracking programs. For more information about the National Environmental Public Health Tracking Program, visit www.cdc.gov/ephtracking.

For additional information, please visit

• Private Well Resources for Environmental Health Programs
• Groundwater Awareness Week