The Palo Alto Regional Water Quality Control Plant provides wastewater treatment and disposal services for the Cities of Palo Alto, Mountain View, and Los Altos; the Town of Los Altos Hills; East Palo Alto Sanitary District; and Stanford University. These agencies are identified in this paper as the “Project Participants.” The Regional Plant Partners (i.e., the wastewater utilities of the entities listed above) and the City of Palo Alto Water Utility have jointly undertaken a Water Reclamation Master Plan, completed in April 1992. The purpose of this Master Plan was to evaluate, on a regional basis, the potential for reclaiming and reusing treated effluent from the Regional Plant. The study area is defined by the boundaries of the Regional Plant Partners, as shown on Figure 1.