Utility Leverages New Real-Time Reporting System

The Windsor Utilities Commission, located in Windsor, Ontario, is considered one of the leading edge utilities in North America. Two treatment plants, three pumping stations and two reservoirs serve approximately 230,000 people in the City of Windsor, the Town of LaSalle and part of the Town of Tecumseh. In addition, the Commission is the first utility in Ontario to offer water treated with ozone to the communities served.

The A.H. Weeks water treatment facility was completed in late 1994 with a capacity of 227 million liters per day. It replaced an old treatment facility that had been in operation since the mid 1920s. When it was built, Windsor Utilities automated the treatment process using Allen-Bradley programmable controllers, including PLC-5s, SLC-500s and a ControlLogix Gateway.

Although the facility was performing well, Dr. Saad Jasim, Director, Water Quality and Production for the Windsor Utilities Commission, knew that the plant floor held critical information that could be used to optimize the treatment process even further. He felt that a manufacturing execution system (MES) would help him capture accurate, real-time process data, share it with others in the company and use the trend reports to help managers make real-time decisions on process changes.

"With access to accurate, real-time information, we could see where there were problems or inefficiencies in the process, such as improper chemical levels," said Dr. Jasim. "Having this information available to operators and managers would improve overall operations, and ensure that our water quality was consistent."

Aside from the internal needs, external forces also prompted Dr. Jasim to look into an MES. In August 2000, the Ontario Government passed the Ontario Drinking Water Protection Regulation requiring all municipal water suppliers to provide quarterly reports on water quality, including a description of the treatment process, measures taken to comply with the regulation and a summary of sampling results. Then, in 2002, the Safe Drinking Water Act was passed, regulating control and testing of drinking water.

"We knew from manual reports that our water met, and even exceeded, the government regulations now in place," said Dr. Jasim. "However, we didn't have an effective way to present it."

Treatment Process

Water enters the A.H. Weeks facility from the Detroit River. Ozone is used as the primary disinfectant. Water is then mixed with aluminum sulfate (alum), polymers. These processes kill germs and bacteria, improve taste and odor, and help settle solids suspended in the water. The water is then moved through the coagulation and flocculation process.

The settled water passes through a filter consisting of a bed of graduated gravel, sand and anthracite. Lastly, fluoride, and a small amount of chlorine is added to the water, to kill any remaining germs and keep the water safe as it travels to the public. The end result is sparkling clear and colorless water.

River of Information

The plant floor devices used to automate and control the A. H. Weeks facility generate volumes of water processing information on temperature, level, turbidity, pressure, chemical levels for ozone, chlorine and alum and more.

Operators monitor basic water treatment information using Rockwell Software RSView operator interface terminals. Redundant HMI terminals help ensure that operators always have an interface into the system, even if one HMI fails.

Working with Rockwell Automation Global Manufacturing Solutions, Dr. Jasim used the existing control and HMI system, adding new functionalities to create an MES architecture. Today, information from plant floor devices is automatically transferred to a central database. A data historian program provides pre-designed data models and analysis tools so operators can run reports on time-series data.

"Prior to implementing the MES, we were using manual, paper reports that were distributed across the facility. We would write down 15-20 sets of data every hour," said Dr. Jasim. "Having a centralized database for all our information was a critical step in being able to decrease paperwork while analyzing and improving the water treatment process."

Operators can monitor information on just about every process function in the plant, including water usage, chemical levels, temperature and filtration. Maintenance data for devices, such as motors and pumps, is also tracked and transferred to the database. Reports that are based on time-series data, such as alum levels for the last three hours, give operators and managers a more comprehensive view of the process, and an opportunity to make process improvements.

"Because the data is real-time, we are able to make process changes immediately," said Dr. Jasim. "For example, if we know that the chlorine count is getting too high, we can decrease the levels quickly, to maintain water quality, save chemicals and cost."

Operators can view real-time data using the HMI stations in the plant, or from anywhere in the world, using a secure Web connection. The paper reports have decreased over 90 percent. If device problems are encountered, or information falls outside pre-set parameters, the system can trigger alarms in the HMI. Operators must acknowledge the alarms or make process changes. Data on each alarm is sent back to the database so operators can look for patterns of recurring problems.

"One surprising benefit of the system was the ability to track information on the disinfectant levels," said Dr. Jasim. "The new system tells us how accurate the chemical levels are, and ultimately, how clean the water is."

Making the Grade

The new MES allows the utility to run the water quality reports required by the Ontario Drinking Water Protection Regulation and the Safe Drinking Water Act. Without the ability to prove compliance, any Ontario water treatment plant could receive severe fines, or be required to issue "boil water" advisories.

"The MES makes it easy for us to comply with the regulations because we can access and report on the information that they require," said Dr. Jasim. "Without this system, we would have been unable to prove to the government that we were in compliance – a problem that could have resulted in fines and unhappy customers."

Future Ideas

Windsor Utilities is in the process of re-engineering its old treatment plant. It is adding new features, such as ozone treatment, to improve the treatment process and match the capabilities of the new facility. Eventually, utility officials plan to tie in the data from the old plant to the new system. Because of the open standards technology the MES uses, Windsor Utilities can tie the old plant, as well as other databases, to the system.