Dublin City Council today claimed continued leaks in the port tunnel were no worse than leaving a bath running.
Amid reports that a 50m stretch of the route was being flooded by torrents of water, officials insisted only a small section was affected and that drainage systems were coping with it.
“The amount of water involved is no more than the equivalent of leaving the bath tap running,” the council said in a statement.
“The leak has no safety implications; either for workers on the tunnel, for the structural integrity of the project or for the buildings and houses above the tunnel.”
The council said the leak occurred when a waterproof membrane was accidentally punctured in one of the two 4.6km tunnel bores resulting in 25 litres gushing down the tunnel every minute.
“It’s the same as leaving your two bathroom taps running,” a council spokeswoman said.
Officials insisted it was the same leak reported in January and added that repair work to fix the floods would not add any extra costs to the already over-budget scheme. The consortium building the tunnel will foot the bill.
“Neither is the leak impeding work on the rest of the tunnel. The water is groundwater and is not polluting anything,” the statement went on.
To date the tunnel has cost €752m – €37m more than originally budgeted – and it is 18 months behind schedule.
Italian sub-contractors, specialists in preventing leaks and floods in tunnels, are now on site and expected to begin repairs. A unique system has been designed for the Dublin tunnel involving a thick waterproof membrane being laid in-between the concrete arches of the bores and a third layer which is attached to the bare rock.
When laid, the membrane, combined with concrete rings, will allow groundwater to find its own path around the outside of the tunnel.
“We are now assured the leak will be stopped within two weeks,” the statement said.
The council said the leaks would not interfere with other snagging works to have the tunnel open by summer, with a spokeswoman adding that 90% of the route had been painted.
Ten minutes of video footage had shown a constant shower of water coming down through the roof, but the council insisted no new leaks had appeared.
The council also hit out at what it claimed were inaccurate media reports about the tunnel adding that it was a challenging project, the largest of its kind in Ireland and the UK.
“It is a major infrastructural project and its construction involves many challenges every day. The current leak is not one of them, despite the way it is being depicted in the media,” the council said.
“Bearing in mind that there are no time or safety, or cost implications arising from the leak and that the situation has not dis-improved, in our opinion it does not justify the extensive, negative media coverage it has attracted.”