A “bubbling” puddle has opened up on a west London rugby pitch as HS2 workers bore a tunnel deep underground to Euston.
A dogwalker stumbled on the bizarre phenomenon at Ruislip RFC on Sunday morning - a month after a mystery foam bubbled up to the surface nearby.
Video shows a murky brown puddle bubbling vigorously behind a sealed-off area of the playing fields that backs onto a primary school.
Locals reported two more areas being cordoned off by HS2 security on regular patrols to keep the walkers and children away.
Sources say air trapped in the ground is being forced upwards as engineers fill tiny gaps around the tunnel with grout. The tiny pockets of air then bubble up to the surface through the waterlogged ground.
It is expected to continue as workers continue to bore the tunnel towards central London.
NEW: More HS2 holes at Ruislip Rugby Club this morning. Locals very concerned. Last time HS2 said the pool appeared as the boring machine had drilled across a pre-existing borehole, causing foam to travel up and pool on the surface. pic.twitter.com/2hNQkeVBIG
— Tom Edwards (@BBCTomEdwards) March 20, 2023
Despite the slurry pool being cleared away, locals raised concerns as to what could happen when digging passes under populated areas as the £100bn project continues to bore 13 miles of tunnels towards Euston.
A dogwalker told the Standard: “It is concerning it keeps happening. HS2 has been stationed in the rugby club car park since the original incident and have been patrolling the site every hour.
“They’ve also cordoned off two more areas. One with gas or air coming out and another huge puddle.”
The bubbling appeared the week after it was revealed the HS2 high-speed rail line may not arrive at Euston for almost 20 years, according to Labour MPs.
Labour shadow transport secretary Louise Haigh said leaked Government documents “suggest it will terminate on the outskirts of London until 2041”.
Her remarks appear to confirm fears that Old Oak Common, a new interchange station being built in north-west London, will become HS2’s London terminus until Euston’s HS2 station is finally finished after construction was delayed in a bid to ease soaring costs on the £100bn-plus project.
A HS2 spokeswoman said: “Air appears to have been forced to the surface through waterlogged ground via a pre-existing borehole during tunnelling operations. The area has been temporarily fenced off and remains safe.”
