Recognizing the need to provide national guidance on water reuse regulations and program planning, the U.S. Environmental Protection Agency (EPA) has developed comprehensive, up-to-date water reuse guidelines in support of regulations and guidelines developed by states, tribes, and other authorities. Water reclamation and reuse standards in the United States are the responsibility of state and local agencies--there are no federal regulations for reuse. The first EPA Guidelines for Water Reuse was developed in 1980 as a technical research report for the EPA Office of Research and Development (EPA, 1980). It was updated in 1992 to support both project planners and state regulatory officials seeking EPA guidance on appropriate water quality, uses, and regulatory requirements for development of reclaimed water systems in the various states (EPA, 1992). The primary purpose of the update issued in 2004 was to summarize water reuse guidelines, with supporting research and information, for the benefit of utilities and regulatory agencies, particularly in the United States (EPA, 2004).