Wet Basin Municipal Water District – Brewer Desalter Control System Upgrades

In 2019 ProjectLine completed a Control System/SCADA upgrade design for West Basin MWD’s 1980s-vintage, 1 mgd Brewer Desalter, which includes a well pump, RO treatment, and chemical injection systems. The control system was an antiquated GE system installed in 1993, and the challenge was how to specify SCADA upgrades with a clear scope of work given missing as-built documentation. The project required lots of digging for information and weaving what was gathered into drawings and specifications:

• Prepared condition assessment based on site visits and inspections, and based on this recommended control system replacement scope and approach.
• Created documentation for existing control systems, including P&IDs (there were none, not even a process flow diagram), an I/O list, and system architecture diagram.
• Documented how existing system works, including control narratives, alarms and reporting requirements.
• Traced instrumentation conduits to/from I/O panel and control panel, which allowed for planning re-use of existing conduits and conversion of the existing I/O panel into a pull box for redirecting signals into the new control panel.
• Documented requirements for new SCADA system per latest West Basin MWD standards, including Allen-Bradley ControlLogix PLC, Wonderware In-Touch Edge HMI with historian, and radio communication with headquarters location.
• Included above information in specifications and drawings as bid-documents, specifying hardware and software scope, and construction sequence for adding new control panel and cutting over signals from existing control panel being replaced.

Project Status: West Basin MWD put the SCADA upgrades on hold in 2020 pending coordination of SCADA upgrades with electrical and other upgrades for the overall facility.