A DISUSED industrial tip which conservationists say contains toxic minerals and possibly cyanide is tumbling into the River Aire opposite historic East Riddlesden Hall in Keighley.

And lead levels in soil at disused Marley Tip have been recorded at more than six times the safe domestic limit - prompting concern for the health of footballers who play on the grassed-over area old waste site, now known as Marley Playing Fields.

Hidden contents of the tip have been exposed because erosion has exposed a 30ft sheer cliff face full of broken glass, china and rubbish which is falling into the Aire, making banks of dangerous debris, said conservation group, the Aire Rivers Trust.

Vivid red ferrous oxide from rusted iron is also seeping out of the tip and into the water below.

Trust chairman Kevin Sunderland has called on tip owner Bradford Council to act now to prevent a potential ecological disaster.

"This weeping tip is the biggest eyesore on the River Aire and something needs to be done urgently," said Mr Sunderland, standing beside the otherwise beautiful stretch of river beside 17th century East Riddlesden Hall.

"The tip opened in the 1920s and catered for the town and its factories and 30 foundries, and nobody really knows what got dumped in there.

"Times were different and people didn't care.

"Basically nothing's been done and although the river at this point seems healthy with trout and grayling, it's certainly full of broken glass and debris.

"We are hoping to get salmon up here soon, but what's the point of that if a drum of cyanide suddenly bursts in the tip above?

"Bradford Council must use reserve funds to pay for piling and boulders to hold back the collapsing tip.

"It's not right how it is and there needs to be fast action."

In 2013, Bradford Council commissioned Leeds City Council geotechnical experts to write a report on pollution at Marley Tip, which noted the slope to the river was too steep to be stable due to river erosion and advised building "a retaining structure" and a 45 degree slope covered with plant cover.

It also noted: "It would be prudent to undertake some near surface topsoil samples to determine if the consistently elevated lead levels (6.2 times residential soil guideline values) could represent a risk to the end users for the football pitches."

None of Bradford Council's officers expert on Marley Tip were available for comment yesterday as to why the problem had not been resolved two years after the Leeds Council report or to confirm if those tests for lead in the football pitches had been carried out.

But Jonathan Brewer, general manager of the National Trust-owned East Riddlesden Hall, said: "We are aware of an ongoing problem and are in conversation with the Environmental Agency and Bradford Council about it."

An Environment Agency spokesman said was aware of the situation.

“The Environment Agency has investigated the potential impact that the historical Marley Tip at Keighley could be having on the River Aire," he said.

"We have carried out water sampling upstream and downstream of the tip, and we have found that it is having no impact on water quality."