Document fragment from DEP Box 53 regarding West Street

NYC 9/11 Public Portal Document

U ■ Hillmann Environmental Group, LLC

11. Bulk and heavily accumulated dust/ debris samples were collected with a disposable plastic spoon and placed in a re-sealable plastic bag. When accumulations were not great enough to facilitate this sampling method, tape or a mixed cellulose esther (MCE) filter was swiped over the dust covered surface to offer an qualitative indication of asbestos presence.

• Analysis of bulk and heavily accumulated dust/ debris samples was conducted by Polarized Light Microscopy (PLM) in order to characterize the asbestos content of dust/debris samples. Because of the analytical method used to determine asbestos content in heavily accumulated dust/ debris samples, which is identical to the method of analysis used for bulk samples, these results are included in the appendix • under the heading of Bulk Sample Lab Data.

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■ SECTION 4— DISCUSSION

The discussion below is a summary of air sand bulk sample findings obtained by Hillmann.

■ 4.1 Outdoor Airborne Asbestos Fibers

■ In general, the buildings constituting the World Trade Center did not contain extensive levels of friable asbestos containing materials at the time of their collapse. Nonetheless, asbestos levels in the air of the downtown area have been one of the highest levels of concern for health and safety since the World Trade Center collapse. Hillmann has recently obtained extensive outdoor sampling for asbestos levels in the • ambient air in Downtown Manhattan for various clients. In the initial days after the collapse of the World Trade Center levels of airborne asbestos were elevated. However, since that time levels of airborne • asbestos fibers have been below the EPA NESHAP standard of 0.01 fibers/cc. It is unlikely that outdoor concentrations of asbestos would lead to the re-contamination of the Financial Center Marriott.

4.2 Indoor Airborne Asbestos Fibers

■ The preliminary assessment of airborne asbestos concentrations at the Hotel was conducted on September 18, 2001. The results of this sampling found fiber concentrations analyzed by PCM to be in excess of the ■ acceptable level of 0.01 f/cc. Those samples analyzed using TEM revealed asbestos structures to be present in these samples below the concentrations deemed acceptable for re-occupation by New York ■ City standards.

■ Air sampling continued for the duration of the cleanup of Roy's Restaurant, the adjoining kitchen and adjacent lobby. This cleanup began on September 26, 2001 and continued until September 30, 2001. Air sampling conducted outside of the work area during the cleanup often indicated fiber levels in excess of the 0.01 f/cc deemed acceptable by OSHA. TEM analysis of these same samples identified the presence of asbestos structures among the fibers, but rarely in excess of the 70 structures per mm permissible under New York City regulation. All of the final air test samples collected after the clean-up was • complete passed the New York City clearance air quality standard.

After the contractor had completed the clean up of Roy's Restaurant, the adjoining kitchen and adjacent lobby, the area was inspected by Hillmann's industrial hygienist. Final air tests were conducted inside of the work area. Four (4) of the five (5) TEM samples analyzed, evidenced no asbestos structures. Less than 10 asbestos structures were identified on the fifth sample. This was well below the asbestos level acceptable for re-occupancy in New York City.

■ Marriott World Financial Center/Project Number YI-3508 ■ Page 4

NYC-WTC 000131159