Encompassing the Advantages of a SCADA System
The city of Riverside, Calif., receives its water supply from wells in the Riverside and San Bernardino areas, treatment plants and a water wholesaler. The water is stored and/or transmitted using pump stations and regulating valves through the city’s pipeline infrastructure to its residents. In addition, the city and Gage Canal Co. (GCC) provide irrigation water for customers through similar facilities.
The city of Riverside recently completed the installation of a new supervisory control and data acquisition (SCADA) system to monitor and control 95 water supply, treatment, storage and distribution facilities throughout its service territory in two counties.
The purpose of this project was to replace the existing, outdated SCADA system that had reached the end of its useful life, was not reliable and could no longer serve the city’s present and future needs.
In addition, the system’s telephone-based telemetry system was outdated and expensive to lease and maintain.
Design and specs
The SCADA system used by the city of Riverside incorporated design drawings and specification developed by MWH in its Pasadena, Calif., office.
Yitzhak Nevo, principal engineer for MWH, was the project manager who developed and managed the design and construction of the project.
The design of the new SCADA system started with discussion with city staff as part of a needs analysis to determine the operational, control and monitoring requirements of the city’s Public Utility Department–Water Operation.
A communication study that followed the needs analysis recommended the use of spread spectrum radio for the communication network part of the SCADA system. The analysis and the study took into consideration life cycle cost, existing conditions and future needs, as well as the latest developments in software and hardware technology and communication that would best benefit the city and the water operation.
The final design of the SCADA system and its new communication network met the city’s goals of having a reliable water operations SCADA system that would improve operation, maintenance and customer service, and provide rapid response to emergencies. The SCADA system would also generate operational data that would be used by engineering staff for planning and improving the city’s water system infrastructure.
“The new SCADA system ensures our water customers reliable service and helps our field engineers service and maintain equipment efficiently,” said Randell Carder, senior water controls system technician/supervisor for the city of Riverside. “Additionally, by switching the communication system from leased telephone lines to a radio communication system, the city saves about $60,000 annually.”
SCADA system upgrade
Following the design, and as part of the public bidding process, MWH and city of Riverside staff conducted a pre-qualification process to establish a group of qualified SCADA system contractors.
The purpose of the pre-qualification was to ensure that any firm from that list who is the lowest bidder would construct and implement the SCADA system as designed to the satisfaction of the city.
Transdyn, Inc. was the lowest bidder out of several firms that were pre-qualified. The company was awarded the contract to replace the city’s outdated SCADA and tone telemetry system with a complete, integrated and functional new SCADA and communication system that met the design requirements and the city’s present and future needs.
The new SCADA system servers, network and communication hardware, and other peripherals, are located in the main control center, which is at the city’s Utilities Operation Center (UOC).
The SCADA system comprises Dynac SCADA software running on dual redundant hot–standby servers.
If a primary server fails, the functions of the failed server switch automatically and seamlessly to the standby server without affecting the continuity of the system operation, thus providing a high level of system reliability and availability.
The two redundant servers communicate with an RAS server and multiple PC workstations over a fast Ethernet local area network (LAN) that extends to the dispatch center and adjacent offices at the UOC. Two workstations are located at the emergency dispatch center at the UOC to provide fast response to alarms and other operational emergencies on a 24/7 basis.
Additional workstations at GCC are connected to the LAN via leased ADN lines. The remote connection enables GCC staff to monitor and control its irrigation operation. Riverside also has remote access capability to GCC operation and can take over its operation if the main communication line fails.
The water operation staff is capable of remotely accessing the system via the RAS server for monitoring, and control operation using notebook computers.
The remote access is performed using either direct dial-up phone lines, the Internet through a secure VPN connection, or through the radio system by connecting to a local network hub located in strategic areas.
The communication system network consists of 84 remote sites equipped with IP/Ethernet 900 MHz spread spectrum radios providing 512 kbps bandwidth. The master radios at the operations center and at seven repeaters sites are also providing a dual redundant configuration.
Each remote facility is equipped with a programmable logic controller (PLC) that automatically controls the equipment, such as pumps and valves. It collects real-time process and operational data such as flow, pressure and level, and transmits the data back to the UOC via the IP/Ethernet spread spectrum radio system.
The PLC also enables the operators to remotely operate the facility manually. The data collected is then displayed and trended on a monitor, as well as archived for reporting, planning and future reference. Some operation data is used for regulatory compliance, such as chlorine residual content in the water.
Transdyn’s Project Manager Phil Jacobs added, “A pilot project is currently underway to add video security surveillance cameras at three of the remote sites. This is part of the Homeland Security requirements. Images from the cameras will be sent back to the UOC via the IP/Ethernet spread spectrum radio system for display on the Dynac operator workstations.”