Most municipal water and wastewater treatment plants look like they're built to last forever, but even the longest lifecycles eventually end. And, after decades of faithful maintenance and minor repairs, these venerable systems and facilities need to be replaced—including their process controls.
Such was the case in Enid, Okla., which has about 50,000 residents and is located 70 miles north of Oklahoma City. The city's Water Production Dept. is responsible for the maintenance and operation of the water collection and distribution system, and coordinates with its wastewater treatment facilities. Besides serving Enid itself, this system also serves a three-county area, including the towns of Ringwood, Ames and Drummond, Okla. The collection system produced an average of 11 million gallons per day (mgd) with peaks of 20 mgd in the summer. It includes approximately 140 producing underground water wells with 200 miles of collection lines, 23 million gallons of storage tanks, seven pumping stations and two treatment plants. Both the production department and that wastewater system are supported by the city's Technical Services Dept. and in-house system integrator Roy Robins.
Updates Over the Years
The bulk of its water collection and distribution facilities and its water treatment plant were built in the 1940s with some sections renovated in the 1980s. However, its main wastewater plant reached 80% of capacity a few years ago, which was the level at which the Oklahoma Environmental Quality Dept. had mandated Enid's system be expanded with a new plant. Now nearing completion, the new plant will treat 12 mgd and have a maximum capacity of 32 mgd when it opens during June and July 2012.
Likewise, the city's Water Production Dept.'s process controls for collection and distribution had been updated several times over the years, but some controls had become old and lacked vendor support, while others needed to be improved and expanded. Originally consisting of pushbutton controls, hardwiring and relays, it evolved to use segment-line-controlled HMI and then ActiveX-based I/O and controls.
"Our water collection and distribution controls used to be all two-wire hardwiring, huge control panels and relay boards with no communications, and so they had to be manned 8 hours per day," says Robins. "This was mostly pulsed outputs, and not even 4-20 mA. At night, flows would be set, and we'd have autodialing for specific alarms. The problem was that it was all board-level troubleshooting, and so it eventually became outdated, replacement parts eventually became unavailable and suppliers went out if business."
Later, Enid's water productions controls migrated to Modicon, Allen-Bradley and Koyo PLCs, which used integrated chips and RS-232 communications, and recently began considering Ethernet.
On the wastewater side, Robins reports the department implemented 2.4 GHz wireless components about 10 years ago to communicate with four PLCs on two traveling bridge structures on rails, located in its tertiary effluent application in its non-potable processing area and anaerobic solids building. The HMI for these systems also migrated from using ActiveX controls to an interface that Enid's Technical Services built on its own using Visual Script software and an OPC server.
However, in 2007, Microsoft ended its support for ActiveX, and so the Technical Services Dept. had to seek a new control system, and migrate to it without stopping water production or treatment. The city evaluated multiple solutions, and then settled on Iconics' Genesis32 HMI/SCADA suite for water production and distribution, while still retaining some ActiveX controls for wastewater.
"Some of us are close to retirement, and so we wanted an HMI/SCADA system and software that other staff could pick up and run with in the future. It really had to have the consistency and longevity of the water department itself," explains Robins. "Likewise, our HMI/SCADA has to benefit the city and not waste its money, and being able to do system integration in-house saves even more. Genesis32 worked well and reliably with our well, pumps and communications, and gave us the confidence to add more Iconics solutions when we began to standardize all of our HMI software in 2011."
Most recently, Enid's Water Production and Technical Services departments again researched several alternatives, and decided to upgrade to Iconics' Genesis64 64-bit HMI/SCADA software, including GraphWorX64 vector-based 2D/3D graphic design and WebHMI web-based, real-time automation. The department also picked Iconics' OPC Server Suite, which supports both OPC-UA and OPC-DA connectivity.
Following a 60-day development cycle, the department initially used their new Iconics software to design and implement their new water production control system. The goal was to standardize on the selected software and provide an interface with ease of access for all operators. Using Genesis64 resulted in an accurate 3D view of remote stations and pump rooms. The department is also implementing Genesis64 at the city's new wastewater treatment plant with help from Integrated Controls, a system integrator in Olathe, Kansas.
"The 3D screens we added in 2011 aren't true visualizations, but they are correct representations," explains Robins. "A lot of the programming on these pages is hidden, so we could keep hem simple and uncluttered. Soon, we're going to add more graphics, including 3D showing internal rotation in our pump rooms, and the ability to look outside in our reservoirs, too. We're trying to give our operators a one-click interface, so they don't have to search, but can start at their water production or water treatment overview pages, go right to each individual plant and all the indicators each contains, and set flows, add chlorine or do other tasks.
Back on the water production side, Enid's new system handles over 1,400 tags, which now integrates with its Koyo PLCs from Automation Direct. Iconics' OPC Server Suite software also ties into additional hardware including wireless, serial and networking connections, including UHF, VHF and Frequency Shift Key (FSK). Among the Microsoft products in use are Windows Server 2008, Security Essentials and SQL Server.
"It's 50 miles to our Cleo plant in Springs, Okla., and our furthest well is 60 miles out, so being able to communicate wirelessly with these systems saves us a lot of gas and labor. We use MDS radios to communicate with our pump stations. And, about 45 wells communicate with our Ames plant, which then communicates back to Enid," adds Robins. "Also, this year, we want to replace some two-wire devices with licensed, 450-MHz components that will convert our serial radio communications to run via Ethernet and Internet Protocol (IP) addresses."
In general, Enid's Water Production department saw several benefits in implementing Iconics software.
First, they wanted a solution that would integrate seamlessly with Microsoft SQL Server. Next, they wanted HMI/SCADA software that they considered secure enough for a municipal project. They also wanted HMI/SCADA software that would allow for ease of programming for their operators, which they found within the Workbench, the centralized Web-based interface that makes it easy for users to open Genesis64 products and configure components, runtime, and security. Finally, the department wanted a solution that easily integrated with OPC technology and standards, which is handily provided through Iconics OPC Server suite. An additional benefit comes from Iconics WebHMI. The department uses the software to access a central server via web browser as part of their water management controls.
As in the past, future plans for the department are to expand the water production system, as well as integrate more web and mobile access. "One of the best aspects of our Iconics' HMI/SCADA system is that all its devices and protocols are expandable, and so we can add capabilities and communications with little cost," adds Robins.