Environment Agency sees off legal challenge to HS2 pollution

Campaigners concerned over the potential pollution of a chalk stream by the construction of a tunnel through the Chilterns for the HS2 rail project have failed in their legal bid to overturn the Environment Agency’s consent for the works.

High Court judge Mrs Justice Lieven refused to allow a legal case against the regulator over its decision to grant permission for the construction of a 16 kilometre twin tunnel lying between the M25 and South Health in the Chilterns, in what campaigners have called a “disappointing outcome”.

Misbourne Environmental Protection (MEP) fears that the HS2 tunnels, the longest on its route, pose a “very significant risk” of polluting an aquifer that provides London with 20% of its drinking water.

The local campaign group is also concerned about the scheme’s risk to Shardloes Lake and the river Misbourne, the chalk stream that runs through it.

It applied for permission to take the agency to court on the grounds that it had failed to consider the cumulative impacts of the works; had misinterpreted the Water Framework Directive regarding temporary impacts; and failed to require a permit for the discharge of grout containing bentonite into the aquifer.

HS2’s use of bentonite, a form of clay used mainly in the construction of ventilation shafts and foundation piling before concrete pouring, was of particular concern to the group.

It highlighted a statement from Align JV, the main contractor for the tunnel works, that the grout would set within 30 seconds of entering the watercourse, unless conditions there were fast-flowing. It admitted in court that such conditions were “ubiquitous” throughout the Chilterns.

This risked the grout travelling for hundreds of metres from the tunnel, potentially blocking up fissures in rocks and disrupting the flow of the chalk stream, they said.

However, Mrs Justice Lieven refused the application for judicial review on all grounds. On the issue of whether a discharge permit was required for the grout, she ruled that since HS2 had fully considered all the factors highlighted by the claimant, and concluded that the risk of grout migration was “extremely low”. The agency had accepted HS2’s analysis and approach.

“So long as HS2’s approach was not arguably wrong in law, then there are no grounds to judicially review the EA’s decision,” she stated.

MEP said it accepted the ruling, but blamed Parliament, which it said had given legal approval to HS2 “to damage and pollute the chalk stream”.

The group added that it would be paying “close attention” to Align JV’s actions. “The entire liability for delivering this tunnel without impacts to the water bodies now rests with them,” it said in a statement.

A spokesman for the Environment Agency said: “We take the protection of groundwater and watercourses – and particularly chalk streams – very seriously, as well as the protection of the wildlife and ecosystems that rely on them. 

“Our dedicated technical specialists meticulously reviewed the HS2 plans, and the inaccurate statements made by this group about that work have caused unnecessary concern to local communities.

“We have been working closely with HS2 Ltd and their contractors to ensure they comply with all relevant legislation, and we also continue to work with local areas, community groups, the water industry, and local authorities to ensure the environment is protected throughout the project,” he said. 

Misbourne Environmental Protection Ltd, R (On the Application Of) v Environment Agency is available here.