The Regional Wastewater Facility serves eight South Bay cities and four districts and is the largest tertiary wastewater treatment plant in the Western U.S. As part of a major infastructure rehabilitation, the water treatment process is being upgraded at all stages for optimal plant operation. The design-build cogeneration portion of the project includes four 4 new low emissions iternal combustion engines, a heat recovery system and a gas treatment system to improve operational reliability and efficiency. It will enable full reuse of the digester biogas to generate heat and power for plant operations.