Road construction leads to leachate problems for Biffa

The problems were, in part, an unseen side-effect of the construction of a new access road.

Biffa Waste Services Ltd, which operates the landfill site in the former quarry at Houghton Le Spring, appeared before Sunderland Magistrates this week (20 February). It admitted five charges of breaching its environmental permit during 2010 and 2011.

Leachate is a toxic liquid produced by the decomposition of organic waste. Waste sites are required to contain it to protect the surrounding environment.

David Brooke, prosecuting for the Environment Agency, told the court that Biffa’s management of the liquid running from the tip was inadequate. He said that Biffa had breached its permit by allowing leachate to escape from the site, and by failing to notify the Environment Agency about the pollution.

Leachate control is particularly important at Houghton Le Spring because the quarry is situated on a Magnesian Limestone aquifer that feeds into the drinking water supply to the City of Sunderland.

The Environment Agency, which issues the environmental permits that allow the firm to operate the waste site, carried out an investigation after pollutants were recorded in groundwater at nearby boreholes in April 2010. Investigations to determine the source of the pollution found leachate was leaking outside of the landfill’s protective lining wall.

Investigating officers believed this to have been caused by the construction of an access road in July 2009, which inadvertently provided a route for the leachate to pass over the protective walling.

In a separate incident leachate was seen spilling out of one of the site’s leachate storage tanks, creating a stream of the liquid on an area outside of the site’s protective barriers. This occurred because inadequate controls had been used by Biffa to prevent the tank from overfilling.

Environment Agency pollution prevention team leader Graham Donachie said: “We are pleased with the outcome of this case and believe it shows that this sort of environmental pollution, whether deliberate or not, will be treated seriously.

“There were a number of management failings on site at the time which contributed to the pollution and this case highlights the need for landfill operators to have in place effective and comprehensive operating and monitoring practices. It also highlights the need for operators to inform us when something on site happens that has the potential to damage the environment.”

In mitigation, Biffa told the court that it takes its environmental responsibilities seriously. It said it had co-operated fully in order to prevent further pollution, and that it had removed and reconstructed the access road in line with Environment Agency design guidance.

Biffa added that, although the aquifer was affected by the leachate, there would be no impact on the safety of the public drinking water. The firm is also required to drill more boreholes so that the spread of the contamination can be more accurately monitored.

Biffa was also ordered to pay £26,949.27 in costs, plus a victim surcharge of £15.

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