A presentation on a unique design/build and integration of an automation control system upgrade with a redundant Allen-Bradley PLC control and Rockwell Automation distributed SCADA monitoring system for a 12 MGD wastewater treatment plant including cellular wireless communications to 12 remote pumping stations. The upgrade was performed without interruption to the plant operations and provided alarming and voice annunciation with WIN911. The paper describes all major “state of the art” ControlLogix PLC, RSView SCADA and wireless architectures utilizing AirLink cellular radios and OPC communications to remote controllers such as MultiTrode. Data analysis and reporting was performed with PlantMetrics and RSSQL Historian. Also included is a discussion on procurement methods and budget monitoring. The project was performed on time and below budget.
Schofield Wastewater Treatment Plant is located at Wheeler Army Air Base near the center of the island of Oahu adjacent to the town of Wahiawa, Hawaii.
It was built in 1975 with several modifications thereafter. Raw influent is supplied from twelve remote lift stations within a 15-mile radius of the plant. The plant has a maximum flow design of 12 MGD with a daily average of 2 to 3 MGD. The plant had a simple control system consisting of mostly relay logic operating the EQ basin pumps and RAS pumps, Effluent pumps etc. However, the operators mainly ran the plant manually and relied on an AutoCon alarm system that operated in conjunction with a Zetron telephone dialer. Since 1975, the US Army Department of Public Works (DPW) operated it with additional support from contract personnel.