The Environment Agency received 39 complaints about Welbeck landfill site between June 1 and September 7 and is investigating “gas management” at the tip.

Earlier this year a group of residents were awarded compensation for the stench they endured during the summer of 2003, when the site included a composting facility.

But local action group Residents Against Toxic Scheme (RATS) claims powerful gases are still not being properly treated by site operators Welbeck Waste Management Limited (WWML).

President Paul Dainton said: “The ongoing stench continues on a regular basis while enough gas is flared off into the atmosphere each day to power 8,000 houses – thus depositing all the noxious gases directly onto the people of Wakefield.”

He accused WWML of stalling plans to build a power generator to burn gas at the tip, which was originally to be installed in December.

A spokesperson for WWML said: “The installation of the landfill gas control and utilisation plant at the site is predicted to take place in 2008 rather than by December 2007, as previously anticipated.

“The installation of the new plant is a very complex project and as such we need to ensure that all necessary details are in place and some of these details have taken longer than anticipated.

“We regularly monitor for landfill gas odours off-site and have not found any. Similar independent monitoring is also undertaken by the Environment Agency. The landfill is highly regulated and WWML takes its environmental responsibilities very seriously and fully co-operates with the Environment Agency.”

An Environment Agency spokesperson said officers regularly monitored the site.

Rosa Burghardt, environmental management team leader, said: “The agency is investigating two alleged breaches of the site’s operating conditions. This investigation relates to gas management at the site but as this investigation is still continuing we are unable to comment further.”

Anyone with complaints can ring the EA’s 24-hour helpline on 0800 807060.