Environment chiefs say they expect the water quality to return to normal within the next few days after a fire in the city polluted the canal - as it emerges 1,000 fish may have been killed.
Chemicals spilled into the canal after the inferno broke out at packaging and recycling firm Tradpak, on the industrial site at Armley Road, on Monday.
The Environment Agency said initial estimates have increased as their staff, together with the Canal and River Trust, continue to clear the river of dead fish.
The canal is now open to boat traffic after it was briefly closed to try and contain the pollution.
A spokesman from the EA said: “We are now seeing the pollution that was in the affected areas start to disperse. We’ve had teams taking water samples downstream of the canal and into the River Air, monitoring the levels. Due to the quality of the water in the unaffected parts of the canal and river, it is going to disperse the pollution so it will no longer be harmful to the local community. We’re monitoring that over the next few days.”
He said as the water quality improves, the fish population is expected to replenish quickly.
This is largely down to the finding that the majority of the dead fish were juveniles, and the larger fish - which can breed - managed to swim upstream to survive. He said: “There’s still quite a healthy population despite this loss. We expect it will be a few weeks, or months, for the fish population to replenish itself.”
Fire crews are expected to remain at the scene for the next few days. Yesterday, plumes of heavier smoke could be seen as hotspots of fire were uncovered and put out, as the demolition teams worked on clearing the debris at neighbouing Hazel Products. The cause of the fire is still unknown, but police confirmed they are treating it as a crime scene until they know more.