ENVIRONMENT experts have confirmed the River Colne was heavily polluted by the Grosvenor Chemicals fire.

The Environment Agency has also revealed that the River Calder has also suffered some ill-effects as a result of Monday’s huge blaze.

As many as 150 firefighters from across West Yorkshire were called to battle the inferno, thought to have been caused by an explosion in a boiler room, at the Linthwaite plant in the early hours.

Their operation was coming to an end yesterday after demolition work on a collapsed warehouse building allowed them to tackle the seat of the fire.

But the Environment Agency revealed the incident could have a long-term impact on the river and its ecosystem.

A spokeswoman said the firefighting operation had caused chemicals from the factory to run into the river.

“Our tests show the presence of a number of herbicides in the River Colne and we are now looking at their combined impact,” she said.

“More tests will be carried out to see what the levels are.

“Despite the pollution there is life, such as invertebrates, surviving in the Colne and early indications show the pollution has been diluted by other water courses feeding into the river.

“However, levels have been picked up in the Calder.”

The agency has been carrying out rigorous tests on the water around the factory off Lees Mill Lane following the huge inferno.

Having examined a 3km stretch of the river, they found 12 dead fish and none that were alive.

Anglers have reported seeing dead fish as far as Huddersfield town centre and beyond.

The incident follows the prosecution of another company, Slaithwaite-based Sub Micron Industries, for allowing chemicals to pollute the river last year.

The Environment Agency spokeswoman added: “It has been badly impacted in the past and fish stocks have suffered.

“If you think that it has already suffered pollution, it will take a long time now to recover.

“We are sharing our findings with other agencies as part of the ongoing investigation into the fire and its impact.”

West Yorkshire Fire and Rescue Service said its operation was almost over yesterday. Firefighters will continue to carry out regular checks.

The Health and Safety Executive said its investigation will take some time.

British Waterways has reopened Huddersfield Broad Canal and the Calder and Hebble Navigation after getting the all-clear from the Environment Agency.