The Tracy Wastewater Treatment Plant (WWTP) Phase 1B expansion project involved a complex engineering design to upgrade and expand existing facilities constructed in the 1950s. Because of a limited site area, several existing facilities were re-used and old drawings were migrated to 3D models so that both old and new facilities could be represented in one model. The primary goal of the project is to meet stringent environmental regulatory conditions imposed by the U.S.
Environmental Protection Agency.

Upon completion of the project, Tracy WWTP will be able to produce high-quality recycled water that can be used for landscape irrigation, cooling water, and other environmentally beneficial applications. Total estimated cost of the program is $145 million and Phase 1B is expected to cost roughly $80 million. Pre-design was completed in 2003 and the final design was completed in 2004. The project is currently under construction and expected to be completed by the end of 2006.