A flood of grey concrete-like sludge that spewed for hours from an abandoned building in central Athens is linked with tunnel-boring work for a new Athens metro line, the subway development company confirmed Thursday.
A statement by Elliniko Metro said the leak posed no safety or pollution concerns.
Authorities closed sections of Evias and Strofadon streets in the capital’s Kypseli district to traffic on Wednesday afternoon, after the sludge seeped out of the courtyard of an empty building and onto the street.
Elliniko Metro said the mixture of crushed rock and a special foam expelled under pressure during tunnel boring work had found its way through an old sewage pipe into the abandoned building’s courtyard, and from there to the streets of Kypseli. It said the foam is used to protect ground-level structures by counter-acting pressure from overhead strata during tunnel-boring work.
“The project contractors have already removed that material and cleaned the area,” the statement said. “This incident has not led to any issues of security or long-term pollution.”
Tunnel-boring work was carried out in the area between the under-construction stations of Kypseli and Dikastiria on the subway’s delayed Line 4.