Illegible document page header, WTC EPA OIG, Oct 2003

NYC 9/11 Public Portal Document

The demolition of all WTC complex buildings to ground level was completed by late December 2001. WTC 4 and WTC 5 were brought down using a vertical impact system similar to a pile driver.by wrecking-balls. Section 27-1039d of the New York City Building Code This method of bringing down a building required aEEIoy£lLQ£the_BorougJi£pmmissionnJ2flheDepaj1men^ method of demolition. The appropriate borough commissoner was consulted and he concurred in the use of this method.had been (wdaw-ed in New York for over two deeades-; -but- an-exeeption was granted under the special circum-sta-nees that e-x-i-sted-a-ft&Hbe4errorist attack. WTC 6 was brought down using mechanical grapplers and cutting shears. A photo of a grappler is attached at Appendix .with “special remote cutting-shears.”

Both NYCDDC and OSHA officials told us that -tThe WTC site was under continuous dust suppression.(If this is not acceptable then we suggest as an alternative “EPA officials were at the site and observed that the site was under continuous dust suppression.” OSHA officials told us that this dust suppression was very successful, and that two minutes after demolition you could see across the space where the buildings had been. They Although OSHA officials further stated that it would have been too dangerous to send abatement contractors into WTC 4, WTC 5, or WTC 6 to remove asbestos-containing material before demolition, there was no need to do this as there was no asbestos-containing material above ground in these buildings.T

Treatment of Asbestos-Containing Materiais

Both NYCDDC and EPA officials told us that when asbestos-containing material (e.g., pipe wrapping, steel insulation) was encountered during the removal, it was tested and treated in accordance with asbestos abatement procedures. According to the NYCDDC official, the majority of the asbestos-containing material was encountered when removing the remnants of the basement levels of WTC 6^ below the slurry wall.

EPA Situation Reports confirmed the NYCDDC official’s statement about asbestos abatements at the site. The reports recorded instances where asbestos was found during debris removal and asbestos abatements performed. For example, the EPA May 23, 2002, situation report noted that:

Twelve (12) bulk asbestos samples were taken in the Bl, B2, B3, levels of(WTC) Building 6. The samples were taken from sprayed on insulation at the request of NYC DOI. Of the twelve samples, nine (9) should (sic) results were in excess of 1% Chrysotile asbestos, the results rangedfrom 1.30% to 30.80%. The three samples that were not above 1% were detectfor Chrysotile asbestos. These samples

NYC-WTC_000153481