In 1991, the Environmental Projection Agency implemented a regulation to control lead and copper in drinking water, this is known as the Lead and Copper Rule. Since then, there have been minor, short-term and long-term revisions.
Below are some great links to education your self on lead and copper:
If present, elevated levels of lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. The Harwich Water Deparrtment is responsible for providing high quality drinking water, but cannot control the variety of materials used in plumbing components. When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to 2 minutes before using water for drinking or cooking. If you are concerned about lead in your water, you may wish to have your water tested. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from the Safe Drinking Water Hotline or at http://www.epa.gov/dwreginfo/lead-and-copper-rule.