Compliance with the Safe Drinking Water Act (SDWA) and improving its ability to maintain and upgrade its water treatment system led the City of Kewanee to install a state-of-the-art control system that would serve the needs of the city and surrounding community.
The system, installed with help from Engineered Fluid Inc. and Rockwell Automation, cut communication response times in half and greatly improved remote monitoring capabilities.
The Kewanee, located between Peoria and Moline, is a small city in west central Illinois. The water treatment facility houses three water pumping stations responsible for filtering and treating drinking water for more than 13,000 people.
The city was concerned about the ability of its proprietary system to keep up with changing regulations. The existing water treatment system had become more difficult to modify and maintain.
“Replacement parts were becoming obsolete, and alternative technologies needed to increase the lifespan of existing equipment were becoming very hard to find,” said Mike Johnson, project engineer at Engineered Fluid, manufacturers of water distribution equipment.
The City of Kewanee knew it needed an updated control system and identified three criteria for the purchase:
• Flexibility and scalability to stay ahead of tightening SDWA standards;
• Ease of use, troubleshooting and maintenance to reduce unscheduled downtime; and
• Remote monitoring and control of three pumping stations by the city’s lean staff.
Engineered Fluid managed the upgrade project and selected Rockwell Automation to help design and install the new control system, which featured Allen-Bradley® programmable controllers (PLCs) and graphic terminals from Rockwell Automation.
This same technology is used by automated factories and industrial facilities worldwide. The control system works well with the city’s current Reverse Osmosis (RO) filtration system.
To enable communication among the three pumping stations, Engineered Fluid installed an Allen-Bradley SLCTM 5/03 controller at the plant’s central facility and MicroLogixTM 1200 controllers at each of the two remote stations. The controllers communicate via DF1 Radio Modem protocol, which can be used in either a traditional master/slave radio network or in a peer-to-peer, masterless network configuration. This technology has a higher degree of reliability than telephone carriers and allows city staff to take full control of the operation and maintenance of their supervisory control and data acquisition (SCADA) communication networks from any of the three sites.
Engineered Fluid also installed Rockwell Automation Software RSView®32TM human machine interface (HMI) software with Allen-Bradley PanelViewTM 1000 operator terminals for monitoring and tracking the operation of the water purification system.
RSView32 software allows operators to monitor the entire treatment process including water levels, chemical application, flow raters and chlorine content.
Results
Working with Rockwell Automation, Engineered Fluid was able to reduce the communication response time for the City of Kewanee’s RO system in half. Prior to implementing the DF1 Radio Modem protocol, it took approximately 60 seconds for an operator to receive an update. Now, an operator gets updates in 30 seconds.
“The engineers responsible for monitoring the water supply and making all the necessary changes to keep it clean and available for consumption have increased confidence in the system due to the rapid response rate of the network,” said Johnson.
The SLC 500 and MicroLogix controllers also help keep the water clean by managing how much water is pumped out of the clear wells and keeping the RO systems balanced.
