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Otsu City Public Enterprise Bureau Water Purification Management Center

Azbil’s Advanced Critical Monitoring for Safety was newly installed at the Water Purification Management Center of the Otsu City Public Enterprise Bureau, where water-related facilities are managed and operated, to predict changes in the level of water from a reservoir, thereby ensuring the stable supply of the water so indispensable to citizen’s lives. If a sudden problem occurs, like the failure of a pump at the reservoir, the system helps the city to take countermeasures immediately, and the system also contributes to maintaining a steady supply of high-quality water.

In addition to centralized facility monitoring, systematic water level prediction

Otsu City, the capital of Shiga Prefecture, is located at the southwestern tip of Lake Biwa and is known as a city rich in nature, surrounded by mountains like the Hira range, Mt. Hiei, Mt. Otowa, and Mt. Tanakami. In Otsu City, the Public Enterprise Bureau is engaged in businesses related to the infrastructure that is indispensable to daily life. With the slogan “Partners who support your life,” the Bureau works day and night to supply high-quality tap water and gas, and to treat sewage. Above all, the water supply business works to provide a steady water supply to approximately 154,000 households and 340,000 people in the city.

The Bureau opened its Water Purification Management Center in July 2014. From its central monitoring system, the Center manages the operation of six water purification plants, water facilities such as booster pumping stations and distribution reservoirs, of which there are 137 in total, and the water quality at each location.

“For a water company, the most important thing to avoid is a water outage,” comments Takashi Mizuno, manager of the Facility Maintenance Section.

“Previously, two staff members were stationed 24 hours a day at each of the six water purification plants for monitoring. Since the number of available workers is decreasing due to the declining working population, we have now consolidated the monitoring work performed at each facility into one place and established a system that enables 24-hour monitoring with fewer personnel,” he explains.

“After the establishment of the centralized integrated monitoring system, if an abnormality occurred in the operation of a particular facility, it could be immediately checked from the Water Purification Management Center. However, in the event of equipment failure or other trouble, the estimated amount of water stored in the distribution reservoir, which temporarily stores water for distribution to houses, was still predicted by manual calculation. I was thinking that there was still room for systematization,” says Makoto Okuno, leader of the Maintenance Group.

For example, a typhoon or thunderstorm sometimes causes a power outage, and the pumps for pumping water into the distribution reservoir stop working. In such a case, the staff used to check the decrease in the water level and calculate how long it would take, if the situation continued, until the water level in the distribution reservoir dropped enough to cause a water outage. And based on the result, the staff took the necessary measures, such as repairing equipment or arranging for a water truck to supply water to each house.

“Many of our staff members work in the field, but we have the dilemma that we need highly skilled staff with abundant experience to do calculation work. Another problem was the psychological pressure on the staff if they made a mistake in calculation,” continues Mr. Okuno.

This article was published in January 2022.