Regionalization is often suggested as a means of solving a large number of water supply problems. Unfortunately the word regionalization has many different meanings. Among other meanings, it can be a coordinated approach between independently owned and managed organizations or a single institution that has sole responsibility for water supply over a large area. Finding a universally applicable definition for regionalization is difficult. Passage of the Safe Drinking Water Act of 1974 (PL 93-523) emphasizes the need for water supply professionals to seriously consider regionalization issues. The Act which requires the U.S. Environmental Protection Agency (EPA) and State agencies to develop and enforce water quality standards, will have a significant impact on the ways in which surveyors view their responsibility for supplying treated water to the consumer.