Pollution from sewer outfall a potential factor in riddle over fish deaths in canal

Further testing is being carried out on a canal to find out the cause of fish deaths which have led to it being temporarily closed to freight operators.

The Aire and Calder has been closed to freight traffic till the end of the month Picture: James Hardisty
The Aire and Calder has been closed to freight traffic till the end of the month Picture: James Hardisty

The Canal and River Trust asked operators to reduce the weight of their barges after complaints over numerous fish deaths on a stretch of the Aire and Calder Navigation near Knottingley.

Despite barges running at slower speeds and with lighter loads, the fish deaths still occurred and the trust decided to suspend commercial operations for eight weeks until the end of February.

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Since then they have been sampling water and silt along a 3km stretch and comparing that with samples taken when barges have gone through.

On Thursday a further test run took place with John Branford’s barge Farndale H carrying a lighter-than-normal load, followed by fisheries officers.

Pollution is suspected to be entering the canal from a Yorkshire Water combined sewer outfall. Coun Martyn Bolt, who sits on West Yorkshire Combined Authority’s transport committee, said the theory was that fish were stupefied from pollution in disturbed silt and then were struck by the barges’ propellers.

He said: “If the canals are not dredged to a decent depth then that is the trust’s responsibility. If the pollution is a contributory factor, that’s Yorkshire Water’s responsibility.”

He said if not resolved it could jeopardise plans to reintroduce commercial freight on Yorkshire waterways, including the development of an inland port at Leeds.

He said: “If the trust are going to switch off the tap are you going to invest in a facility? Can you imagine stopping lorries on the M62 and asking them to remove half their load? These are people’s livelihoods.”

However, residents like Pete Girt have been alarmed by the decline in wildlife, with heron and cormorants – once regular visitors – disappearing.

He said he stopped counting when he got to 75 dead fish last year when one of the barges went by. “The canals are there for everybody, for fishermen, for wildlife and the barge guy,” he said.

Bryan Cunningham, from Pontefract, a member of Wilton and Mirfield angling clubs, first raised the issue of fish deaths in 2020. He said: “How can it be called a green venture when it is wiping an environment out?”

Mr Branford, 77, restarted freight deliveries from Hull to Leeds in September 2020 after a break of 19 years, only to be put out of action last December by a breach in the canal at Newbridge. He only got going last September before the latest incident again stopped him from working.

He said the canal was filling up with silt at the rate of one foot a year, adding: “I think the pollution is coming down the dyke and mixing with the silt, then I have to shove through the silt.

“I don’t want to kill anything. If it was deeper and not polluted there wouldn’t be a problem.”

The Commercial Boat Operators Association says the stoppage means between 60 and 75 lorries going to Leeds carrying sand a week that would otherwise have gone by barge.

Business Development Officer (North) Maik Brown said the trust was sending the wrong message by closing the stretch to barges. He said: “Eight weeks is a hefty length of time to close a canal to commercial freight. If there was an environmental problem on the M62 they wouldn’t close it for eight weeks. They might close it over a long weekend.”

The trust expects to announce its findings next month.

A spokesperson said: “We’re interested to understand whether the sewer outfall could be a possible contributing factor.

"We thank Yorkshire Water for their help as we investigate all potential causes of this problem, as we work to restore freight movements as quickly as possible.”

Yorkshire Water said in December they had checked and found “no indication of incorrect operation of our assets or sewage escapes to the canal”.