Water Treatment SCADA

City of Tempe
Tempe, Arizona

Custom Automation designed and implemented a supervisory control (SCADA) system equipment and software retrofit for the City of Tempe to update and upgrade their water treatment plants.  An Operator Interface (OI) was installed to oversee the operation of the Tempe South water plant, Martinez water plant, and Kyrene waste water treatment plant.

The Tempe Water Management District consists of two water treatment plants: Martinez and South, a wastewater reclamation/treatment plant: Kyrene, and 38 field sites including wells and metering stations. There is also a Master Control Center where all sites are monitored and controlled via the SCADA operator interface and closed circuit video. The plants provide fresh water and waste water treatment for the needs of the City of Tempe and other communities.

The water treatment plants are interconnected via a City-maintained wide area network (WAN). This WAN incorporates fiber optic and 900 MHz microwave links between major sites. The SCADA system accesses the field sites via radio telemetry.

Control and monitoring functions were systematically transferred from an aging DCS system to a SCADA system designed by Custom Automation, one water plant at a time, all without service disruption using the existing PLCs. Custom Automation developed a custom driver to communicate with the resident PLCs until Custom Automation helped replace them with Sixnet controllers.

Custom Automation programmed the Sixnet controllers to replace the aging HP PLCs at the water plants. New functionality was introduced to the SCADA system at the PLC level for more refined control.

Most recently, Custom Automation upgraded the filter gallery automation hardware & programming to support supervisor-tunable automatic filter backwash processing for repeatably consistent backwashes.