About 10 gallons of hydraulic fluid was inadvertently leaked into the Ala Wai Canal when a hydraulic hose failed as a city crew was mobilizing heavy equipment to clear a path for stream cleaning and debris removal at the Manoa-Palolo Drainage Canal about 11:30 a.m. Thursday.

The amount that made it into the canal appeared to be diluting and dissipating, said Health Department spokeswoman Janice Okubo. As a result, Health Department investigators believed the oil was clearing up on its own and not a health risk, she said.

“While the crew attempted to contain as much of the fluid by immediately deploying a boom to contain the fluid and using absorbent pads to collect the fluid, some fluid entered the flowing water in the drainage canal which empties into the Ala Wai Canal,” said Ross Sasamura, director of the city Department of Facility Maintenance.