CONCORD, N.H. (AP) – Environmental officials are encouraging residents to test their water for contaminants like arsenic.

Many residents get their water from private wells, about 90 percent of which are in the bedrock where arsenic can be found.

Arsenic has been linked to cancer, cardiovascular disease, immunological disorders and diabetes.

About 15 percent of wells and public water systems in New Hampshire have a concentration of arsenic in the water that is equal to or greater than federal standards.

The standards restrict the allowed level of arsenic in public water systems to 10 parts per billion.