The sinkhole that swallowed the rear wheel of a District 87 bus Wednesday was caused by a water main break.
Bloomington Water Department Director Craig Cummings said the main break caused some erosion of the soil underneath the pavement.
“It is related a bit related to sewers and the fact that the water, because it was able to get into a sewer and run away, it never surfaced as you would expect a pressurized water main break to do,” Cummings said.
To complicate matters, Cummings said there was a working fire in the same area Saturday night, and when firefighters opened a hydrant, a different main broke.
“This one could have broken at that time, it could have broken sometime after that,” Cummings said. “But, the fact of the matter is when the fire hydrants operate, it really changes the water flow and the pressures in the water main, and it probably was just a weak point in that main and it broke.”
A water department study of the condition of water main assets is coming soon. Cummings said after getting the problem areas and condition list of water and sewer lines, a long term plan with estimated amounts for repairs and replacements will be created.