Updated technology centralizes plant’s control
In March 2000, officials at the Metropolitan Water Reclamation District of Greater Chicago (MWRD) decided to update the control system for treatment process equipment at the Stickney Water Reclamation Plant (SWRP). The plant handles a large volume of wastewater — it has a peak hydraulic capacity of 1,440 mgd, and it serves 2.38 million people. Built in the 1930s, the plant still operates with some of its original control equipment.
The plant’s control technology had become obsolete, and the equipment was not integrated with the control system — it was monitored and controlled by operators at numerous locations. Operators wanted a more up-to-date control system that could be centralized.
SWRP contracted with Kansas City, Mo.-based HNTB to design and implement a distributed control system (DCS) for the plant. Scheduled for completion by 2007, the system will monitor and control the plant’s treatment equipment and associated instrumentation. It also will integrate the equipment through a central control center (CCC).
Operators will be able to control all plant equipment from the CCC, which will be located in a portion of a new building at the Stickney plant. There also will be several area control centers located throughout the plant and at remote sites, where monitoring and control through the DCS will be possible.
The DCS will:
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provide operational control from key locations;
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transmit the process and equipment status information to the CCC, allowing for centralized monitoring of the Stickney service area from one location;
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generate the required operating, diagnostic, administrative and regulatory reports automatically;
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provide critical current and historical data for oversight and long-term planning to the MWRD;
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collect equipment run-time data;
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gather information for energy conservation analysis;
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provide remote control and automatic control as required;
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retain all the existing manual control capabilities; and
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provide uniform operator interfaces throughout the plant.
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Until the installation of the DCS is complete, the plant’s electrical engineering staff will continue to keep the existing control systems running. In some cases, facilities are being operated manually at local control panels.
