Challenge
The Town of Cobourg, located near Toronto, Canada, has reduced operating cost at its wastewater pumping station by 30% after an upgrade to the plant's monitoring and control equipment.
The wastewater treatment system features two pollution control plants with a designed treatment capacity of 3.58 million gallons per day (MGD) at plant 1 and 2.58 MGD at plant 2, plus five sewage pumping stations. The McGill Street pumping station is the largest with a capacity of 4.6 MGD. It is equipped with three constant speed pumps and a magnetic flowmeter.
Before the plant upgrade, the McGill station used a manual float system to control the pumps. It required daily servicing of floats, manual inspection, and operation logging. A technician had to drive to the station, manually check the float operation, select the lead pump, change the chart recorder paper, log the pumped hours and the daily volume pumped as measured by a magnetic flowmeter, and then bring the log back to the office. The technician performed these tasks every day.
Solution
Robert Landry, Plant Superintendent, spearheaded the introduction of a remote monitoring system for the McGill station. He chose Siemens-Milltronics, a leading brand of level measurement and process instruments. Automating the routine tasks proved a successful strategy for improving efficiency and reducing costs.
The EnviroRanger™ ERS 500, a new state-of-the-art monitoring and control system, was installed. Connected to a Milltronics Echomax™ XRS-5 transducer, the EnviroRanger panel mount control unit provides accurate and reliable level measurement. It is also connected to the flowmeter to monitor flow.
The installation eliminated the need for daily on-site servicing. It automated the information gathering, and all pump control routines and sequencing setups. EnviroRanger provides pump control, data-logging, and communications functions. It is integrated into the existing SCADA system running Modbus RTU through a telephone modem. From the comfort of the office at the main treatment plant, the operator can now remotely track pump run-time, pump faults, number of pump starts, instantaneous flow rate from the magnetic flowmeter, and totalized pumped volume.
Benefits
"The EnviroRanger improved efficiency, lowered the cost of operation, and it keeps me informed," said Robert Landry, Plant Superintendent. The immediate benefit was time savings. It eliminated the need for daily manual inspections, manual pump control settings, and data collection. This frees a technician and equipment for other important projects. It improved plant operation and quality control by making more data available for decision-making. The EnviroRanger ERS 500 provides instantaneous monitoring of pump station liquid level, pump status and pump duty cycle. It also records pump starts, pump run times, alarm history, and total pumped volume. The new system permits continuous monitoring of liquid level – a major improvement over the previous point level float system. The investment in automation has proven beneficial to the bottom line. The financial savings were considerable, with operating cost reduced by 30%.
