This project is located at the Arnold Wastewater Treatment Facility (WWTF) and is designed to improve treatment capacity, operational efficiency, and long-term system reliability.

The project includes construction of a new secondary clarifier; installation of a new effluent pump, metering, and flow-splitting structures; and replacement of the existing Return Activated Sludge and Waste Activated Sludge (RAS/WAS) pump station. In addition, two new aerobic digesters equipped with submersible self-aspirating aerators will be added to enhance solids treatment processes.

The project also provides for a comprehensive upgrade of the facility’s electrical and control systems, including a new electrical and control building, motor control center, master control panel, upgraded PG&E power service, and standby generator. Supporting improvements include upgrades to yard piping, grading, paving, power and control conduit and wiring, instrumentation, and PLC/SCADA systems.

Overall, this project represents a significant modernization of the Arnold WWTF, improving treatment performance, increasing operational reliability, and ensuring the facility continues to meet current and future regulatory requirements.