TNT BLAST IS DUE AT WTC SITE
By TOM TOPOUSIS

June 8, 2006 -- Powerful explosions will shake Ground Zero on Monday as engineers test the use of charges to clear bedrock for the Freedom Tower's foundation.

"This is nothing unusual for New York," said Mel Ruffini, the Freedom Tower's project director at Tishman Construction.

....Ruffini said measures are being taken to limit the sound from the blasts. "I've been told we're not expecting anyone as far as Church Street to hear anything," he said.

If the tests are successful, as expected, blasting will be conducted on alternating weekdays for about two months, with three to four explosions each day.

The project will save 2,300 hours of drilling and hammering at bedrock and about 50,000 gallons of diesel fuel, Ruffini said.
New York Post

This was then confirmed in this article from the Washington Post:

Test Blasts Conducted at Former WTC Site
The Associated Press
Monday, June 12, 2006; 3:05 PM

NEW YORK -- Construction crews set off test explosions Monday at the site for the Freedom Tower, producing muffled blasts where the World Trade Center once stood.

If the process passes a review by the Fire Department and other agencies, blasting will be performed several times a day, about three times a week, for the next two months, said Mel Ruffini, Tishman Construction's Freedom Tower project manager.

A construction worker walks by a construction blasting sign at the World Trade Center site in New York Monday, June 12, 2006. Engineers conducted a test blast in the bedrock where they plan to build the foundation for the Freedom Tower. The use of explosives is intended to speed construction, and if the tests are successful, blasting is planned for alternating weekdays for about two months, with three to four explosions each day.

Blasting to prepare the bedrock for construction will produce less noise and dust than jackhammers, and will save two months of work, said Steve Coleman, a spokesman for the Port Authority of New York and New Jersey, which owns the trade center site.

Tourists on neighboring Church Street did not hear anything during Monday's test, and people on other nearby streets heard only muffled sounds, said Coleman.

Politicians and others have been critical of the slow progress at the site five years after the terrorist attack.

Five office towers, a Sept. 11 memorial, a transit hub and a performing arts center are planned at the 16-acre site.
Washington Post