The Occurrence of Contamination in Drinking Water from Groundwater Sources

This chapter summarizes the information currently available to EPA&s;s Office of drinking water on the occurrence of contaminants in public water supplies using groundwater sources. Groundwater has been viewed as a relatively pristine resource, and generally has been used for drinking water without major treatment other than disinfection. However, it has been recognized that groundwater is vulnerable to contamination, particularly with organic chemicals resulting from a range of man&s;s industrial and agricultural activities. Public water supplies, as defined in the Safe Drinking Water Act, are those serving 25 or more people. It is currently estimated that there are in excess of 45,000 public groundwater supplies serving more than 100 million people in the United States. It should be noted that there are also more than 11 million private wells providing drinking water to an additional 25-30 million residents, mainly in rural areas.