As a result, drinking water protection standards differed from state to state. Since 1974, when Congress passed the original Safe Drinking Water Act, EPA has set uniform nationwide minimum standards for drinking water. State public health and environmental agencies have the primary responsibility for ensuring that these federal drinking water quality standards, or more stringent ones required by the state, are met by each public water supplier. When a state water agency or water supplier announces that the standard for a particular contaminant has been exceeded, that may or may not by itself be a cause for alarm, but it can be a cause for action. It is a safety precaution required by the law to alert the public to deficiencies in drinking water quality.
Boiling water kills the organisms that can cause disease.
Therefore, the notices serve as a precaution for the public. Boil water notices are being issued more frequently in recent years. In fact, in 1993 notices were issued by water suppliers in New York City and the District of Columbia, which together serve more than 7.1 million people. At least 725 other communities have also issued notices affecting almost 3 million people in the past few years.