Specifications include, but are not limited to: The City of Tigard owns and operates a public water system which supplies potable water to the Tigard Water Service Area (TWSA), which includes approximately two-thirds of the residents, businesses, and public institutions within the City limits, the unincorporated area of Bull Mountain, and the cities of King City and Durham. The TWSA is currently expanding to include the River Terrace area as development occurs along the City's western boundary. Three (3) of the City's pressure zones are involved in this project and include the 410-foot, 560-foot and 713-foot pressure zones. The 560-foot pressure zone is currently split into eight subzones with seven being fed by the 713-foot pressure zone through pressure reducing valves (PRV) stations
