The Queens-Midtown Tunnel leak was quickly fixed following this month’s accidental perforation, MTA officials said Wednesday — but the city agency responsible for the drilling mishap is still investigating the cause.
“The permanent repair followed immediately and was completed … two days after the initial incident,” MTA Bridges and Tunnels President Cathy Sheridan briefed the MTA’s board.
The leak occurred when a subcontractor working for the city’s Economic Development Corporation — the quasi-private entity that handles public-private partnerships for the city — drilled into the bed of the East River on Sept. 4, inadvertently punching a 2½-inch wide hole through several layers of the tunnel and causing leaks into the exhaust ducting of the south tube.
The subcontractor, Warren George Drilling Specialists, had been tasked with exploratory drilling ahead of a plan to build a greenway along the Manhattan side of the river.
It remains unclear how the EDC’s drilling crew had been so far off course as to drill into a major tunnel.
“EDC has hired a consultant to do an independent evaluation of how this occurred,” Sheridan said. “We’re cooperating with that investigation.”
Adrien Lesser, a spokesperson for EDC, would not say Wednesday who the corporation had hired to conduct the investigation.
“While we won’t speak to the ongoing review of the incident, making sure our projects are held to the highest safety standards is of the utmost importance, and we are taking appropriate steps to ensure just that,” she said in a statement.
Sheridan said her crews spotted water leaking from the ceiling of the south tube around 10 a.m. that day. By noon, they’d tracked the leak to the tunnel’s exhaust system and determined — by taste — that the water was salt water, and therefore likely from the East River.
Just before 12:30 — more than two hours after MTA crews spotted the leak — Sheridan said EDC’s design consultant responsible for the project notified the transit agency of the drilling accident.
Sheridan said her teams didn’t measure the water that entered the tunnel, which MTA chair Janno Lieber pointed out “was never more water than the tunnel’s normal drainage system could accommodate.”
While the breach snarled traffic for hours, a temporary fix was in place by early evening allowing the tunnel to reopen the same day as the accident.
The permanent repair, which involved pumping grout into the void from above, was put in place within 48 hours.
MTA board member David Jones asked Wednesday who would bear the cost of repairs to the tunnel — a cost Sheridan said her department was still calculating.
“I haven’t consulted the contracts, but my answer is not us,” Lieber said.
“Common sense would dictate the MTA does not pay when somebody else makes a mistake and drills a hole in a facility,” he said.
