A blaze in about 800 tonnes of green waste at a water treatment works was today being controlled by firefighters, 24 hours after it started.

Yorkshire Water staff called the fire service yesterday afternoon to the waste water treatment works in Esholt when the mountain of waste caught alight.

A spokesman for the company said the inferno was in the sludge conditioning area and affected about 800 tonnes of waste, which was to be recycled using a process similar to composting.

About 26,000 tonnes of the by-product sludge is produced at the site each year.

The spokesman added: “Our 750-acre sewage works, treating 144,000 cubic metres of waste water every day and safely returns it to the environment, continues to operate as normal.

“It is anticipated that the green waste pile will continue to be damped down by fire crews, who remain on site as a precaution.

“We’re working to establish the cause of the blaze, and would like to thank them for all their efforts.”

At one point, five fire crews were at the incident at the works which were built in 1924 and serve about 700,000 people. Yesterday appliances from Shipley, Idle, Rawdon, Cookridge and Stanningley all attended the fire off Station Road.

Today, firefighters from Shipley and Bingley were damping down at the site.

Esholt will soon benefit from a large bio-energy facility which harvests gas from waste, which is then used to produce electricity. The site already generates 45 per cent of its energy needs through hydropower and anaerobic digestion.

When the hydro turbine was installed five years ago it was the first in the UK to generate power from incoming sewage at a treatment works.