By Vanessa Romo
The city’s Department of Environmen-tal Protection began rock blasting at two new shaft sites on Nov. 1, entering a new phase of construction on the Manhattan leg of Water Tunnel No. 3. At $6 billion, the tunnel is the largest capital construction project ever in New York City.
Explosives 20 to 30 feet below the surface at E. Fourth St. between Lafayette St. and Cooper Square and at Hudson and Laight Sts. in Tribeca are being used to create new water shafts and chambers that will connect to the water tunnel currently being drilled 550 feet below street level. Once they are connected, the shafts, which measure 25 feet in diameter, will convey water from the tunnels to the surface water-main distribution system.
A series of warning horns are sounded prior to each blast, which last about 10 seconds. City regulations limit the blasts to two per day.
Despite dire reports by the Daily News and WINS news radio about noise complaints and rats running rampant because of the underground explosions, Pi Gardener, executive director of the Merchant’s House Museum, a landmarked building erected in 1832, said effects of the blasting have been minimal. The building at E. Fourth St. is next door to the construction site. “It feels like a subway is below us, but it’s not really very noticeable,” she said.
Gardener said a monitor placed in the basement of the museum by D.E.P. measures the vibrations in the building each time a blast occurs to make sure it is an acceptable level. “We’re being handled with kid gloves,” she said.
Charles Sturcken, a D.E.P. spokesperson, said the agency conducted a thorough environmental impact study prior to drilling and blasting to ensure that the community would not suffer any unnecessary disruptions. The agency also hired a noise consultant who has been advising them on the city’s new noise codes.
“We haven’t had any complaints about the noise of the blasts,” Sturcken said. But the agency is aware of complaints about a hum emanating from the shafts. The noise is a result of a machine that prepares the ground for blasting by freezing it, said Sturcken. “The hum will continue for the duration of the drilling and blasting, which should be another two to three months,” he added.
Underground drilling of Tunnel No. 3, which connects Manhattan, Queens and Brooklyn, began in 1970. Completion of the project eventually spanning a total of 60 miles is slated for 2020.
Drilling of the latest Manhattan section started in 2003 and runs from W. 30th St. to the Holland Tunnel, at which point a second section loops north from there up the West Side to Lincoln Center. In all, the new Manhattan segment will measure 8.5 miles and is expected to be activated in 2012.
The two sites currently under construction are slated to become public spaces. “The shaft site at E. Fourth St. will be a public garden with benches to meditate and the Hudson and Laight site, which is part of the Holland Tunnel rotary, will be a tree-planting space,” Strucken said.
