City of Bloomington Utilities reports on February’s water main breaks

BLOOMINGTON From Saturday, February 20 to Thursday, February 25, City of Bloomington Utilities (CBU) crews were dispatched to repair 12 breaks in the water infrastructure system.

While it is typical to see an increase during the winter months, this number of breaks in a short time frame is unusual. CBU has determined that a technical issue with the supervisory control and data acquisition (SCADA) may have been a factor. 

SCADA is the computer system that allows operators at the Monroe Water Treatment Plant near Lake Monroe to ensure adequate supply throughout the 420 miles of water mains across CBU’s service area. Treated water leaving the plant is stored in 7 storage tanks and there are 7 booster stations across the city that maintain water pressure via pumps.

In February, the SCADA system was incorrectly communicating between the plant and one of the booster stations, which prompted a plant employee to accidentally activate too many pumps at once. The result may have been “water hammer,” which is when the pressure in the pipe can rise and fall very rapidly over short time periods. This creates a pressure wave that may have led to ruptures at weak points in the water infrastructure system. 

It is not possible to determine if this factor caused main breaks the week of February 20. Employees at CBU look at several factors when studying main breaks, such as age and material of the pipe, composition of the material surrounding the pipe, and temperature of the air and water on the day of the break.

From the results of internal analysis and best practices in the water industry, CBU has made changes such as installing variable speed pumps and moving to the different pipe material. CBU also started a water main replacement program in 2017 which systematically replaces entire water infrastructure areas. Projects for that program are selected using data such as how many main breaks have occurred in the area and if the pipe supplies a critical customer, such as a hospital or school.

For the SCADA issue, a repair is complete and a new standard operating procedure is in place to help prevent a recurrence. Data on water main breaks is available at the CBU website

If you see activity that looks like it may be a main break, such as water coming out of a crack in the road, please call CBU at the 24-hour line at 812-339-1444.