By Walt Boyes, Editor in Chief
May 15, 2000, was not a good day in the small town of Walkerton, Ontario.
Nearly half the population fell ill—and seven ultimately died—from an e coli outbreak traced to the community's water supply. The incident triggered a wave of stricter quality assurance and reporting requirements for the Canadian province's water and water treatment facilities.
And for the Windsor Utilities Commission, the new regulations were just one factor driving the municipal water treatment authority to upgrade its aging controls infrastructure, according to John Stuart, chief operating officer. The system had last been upgraded in 1994, "so it was due," he told the Water Wastewater Industry Forum at this week's Automation Fair gathering in Chicago. "Our HMI was 'glued together' and our compliance reporting function was insufficient to the task," Stuart said. Plus, the imminent retirement of many of its most experienced workers had the commission casting about for a more sustainable path forward.
"Not all SCADA projects go well," Stuart said. "But this one did."
The utility settled on Rockwell Automation as sole-source supplier for a top-to-bottom refurbishment of its control infrastructure, including many of its medium- and low-voltage drives and motor control centers (MCCs). Key strategic objectives included easier regulatory reporting and trending, as well as building in higher system availability through a redundant controls infrastructure.
"If the plant had kept its original control system and had lost an I/O card, such as the one running the dosing pumps, the control system would fail to add chemicals to the water, which would have compromised the water quality," Stuart said. "In a redundant system, two processors and associated I/O cards would have to stop working for such a failure to occur. With the Walkerton incident fresh on everyone's minds, we were better off safe than sorry."
Stuart wanted a plant control system that could provide accurate track-and-trace capability, real-time collection and recording of historical data, improved knowledge transfer and employee flexibility.
"Our operators are all in their fifties," Stuart said, "and over the years they've known which combination of pumps works the best, for example. We wanted to distill that knowledge and embed it into the control system." Further, the company developed a wireless mobility solution that allows operators to interact with the control system when they are out and about in the plant.
In addition to Rockwell Automation, the utility selected Insyght Systems, a consultant, and ONYX Engineering, a system integrator, to help upgrade the SCADA system.
ONYX installed ControlLogix PACs to replace the aging controllers in the system and gave them redundant power supplies. The PACs are fully integrated to help the operator access plant-wide production information with real-time visibility of water quality, trending loads, levels, clarity and alarms. "Ultimately," Stuart said, "this leads to better plant management."
ONYX also installed FactoryTalk VantagePoint software as the visibility engine. With VantagePoint, Windsor Utilities has unified access to virtually all plant information sources. By tapping into the data gathered by FactoryTalk Historian software, VantagePoint provides visibility into historical production data and puts the information into context through Web-based reports.
"So we gather our last data points on December 31 at 11:59 p.m.," Stuart said, "and by midnight we have the report we need to send to Environment Canada covering our year of activity. These prompt reporting capabilities will facilitate us staying ahead of regulations and allows real-time changes to plant processes. This ultimately avoids downtime, fines or worse."
"We finished this SCADA project on time and on budget," Stuart said. "We got exactly what we asked for—and more."