In the United States, most states require licensing of water well contractors, and in most cases, this means that licensed contractors have passed tests and met certain professional requirements to obtain their license. Canadian provinces, Australian states, and New Zealand also use qualification-based licensing. To find out if a contractor is licensed, contact your state government (licensing is often handled by the Department of Natural Resources or Department of Health).
NGWA.org, the Web site of the National Ground Water Association, provides a list of state agencies that govern licensing and contractor registration. You can contact the National Ground Water Association directly at 800 551.7379.