HS2: Concern over third pool from tunnelling under rugby club

Just beyond the pitches at Ruislip Rugby Club, there is a long line of fences and lots of activity from men in yellow high-visibility jackets.

There is lots of monitoring equipment. There are probes in the ground. There is a slight cone-like depression where brown, bubbling water emerged on 20 March.

Beneath these pitches, 15m (50ft) down, there are two tunnel-boring machines drilling a tunnel to Old Oak Common.

Part of the fencing has been cordoned-off and covered in black plastic. You can’t see what’s behind it.

This is where another tunnelling incident on HS2 happened recently. This is the third time there has been an issue here.

HS2 says a few days ago, a mixture of water cement and sand – grout – was wrongly pumped to the surface through a hole that had been drilled by workers to check ground conditions.

Now there has been an issue with the grout.

The ground here is London clay with sand on top and that is causing the boring machines problems.

Ruislip Rugby Club is a friendly, community-based club. It has found itself at the centre of a lot of media attention as, just on the edge of its pitches, the biggest engineering project in Europe has hit problems.

Jatin Radia is the chair of the rugby club: “The reality is it does cause further concerns because you’ve got local residents, local rugby club members. They’re naturally concerned about what’s going on and asking ‘is it safe’?”

The tunnel-boring machines will eventually go under houses nearby. Speaking to the residents there, most have been reassured by HS2. Surveys have been done on their houses in case there are any problems. But some of them are a bit worried.

Environmental campaigners are concerned about what was in the liquid seen on 20 March. HS2 has said previously it was air and water and it is safe.

Paul Jennings is a local clean water campaigner and says he doesn’t believe that.

He has concerns about what is happening to the rocks below, which store water and are known as aquifers, and wants HS2 work suspended by the Environment Agency.

“Ten years go when we started on the consultation with HS2 and the Environment Agency, we were very concerned that the aquifer would be damaged by what goes on within the tunnel. The tunnel has a lot of fluid running around it and it’s under pressure and that’s going to find its way into cracks and holes,” he said.

“And what has happened here is a fantastic demonstration of what our concerns were at the time. We are still worried as there is still a lot of more tunnelling to be done and we’re not sure what damage has already been done.”

When we were on the pitches filming, we bumped into Mark Kier, who is an…