EA reveals potential scope of its Walley's Quarry gas monitoring error

The Environment Agency is being criticised over the under-reporting of noxious gas emissions at a landfill site

Levels of noxious gas emissions at a controversial landfill site may have been under reported the whole time they were being monitored, the Environment Agency (EA) has admitted.

The EA said this week data was flawed on the smelly gas hydrogen sulphide at Walley's Quarry in Staffordshire, although detail was light.

But on Friday the body suggested how much of its data may be compromised.

Council leaders have called on the government to hold a public inquiry.

Campaigner Steve Meakin, founder of the Stop the Stink group, labelled the situation "absolutely disgraceful".

Stop the Stink in recent years has been among those to protest outside the site in Silverdale amid residents' concerns the gas - which smells like rotten eggs - affects their health.

Mr Meakin said residents had "suspected something [with readings] was amiss for a while", adding: "We wake up with the smell, we go to sleep with it."

Thousands of complaints have been made about the smell from the Silverdale site

After levels of hydrogen sulphide were found to have sometimes exceeded limits, a council in 2021 served a statutory nuisance abatement notice on the quarry which committed to cutting emissions.

The EA reported the following year an overall trend of hydrogen sulphide reduction.

That reporting and data since is now in dispute, with various parties seeking answers over how far off the numbers have been.

Clare Dinnis of the agency said a problem had been discovered in relation to the calibration of the machines used in monitoring.

She said the EA believed that was "likely to have been for the whole period the monitors have been in place around the quarry".

She added, however: "They've still given us a trend, and we still know that those hydrogen sulphide levels have been reducing consistently over time.

"But we can't rely on the hydrogen sulphide data and we absolutely understand that is incredibly distressing, and that's why we're sorry we are in this position."

Regulatory actions had been based on "a whole range of different things, and they haven't been affected by the hydrogen sulphide readings", Ms Dinnis explained.

Last month, Walleys Quarry Ltd (WQL), which runs the site, was ordered to improve the capping of waste there following an unannounced EA inspection.

The EA normally shares data on the site's hydrogen sulphide levels on a weekly and monthly basis.

The EA said while it had temporarily paused publishing the data on learning of the error, it had since recalibrated one of the monitors and was starting to release fresh information.

Council leaders are calling for a public inquiry into the governance of the site

Responding to the EA's admission, Staffordshire Council leader Alan White said: "I think we all wonder how such a basic, but crucial, mistake could happen and then remain unnoticed for so long.

Simon Tagg, leader of Newcastle-under-Lyme Borough Council, the authority which brought the abatement notice, described the situation as a "massive failure".

Both councillors called on the government to launch a public inquiry into the EA's governance of the site.

WQL said: "We will await further information from [the EA] to allow us to better understand the full implications of this development."

A virtual public meeting was to be held on 9 October at 19:00 BST, the EA said.

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