NYC-WTC_000214146

NYC 9/11 Public Portal Document

600 West Cummings Park, Suite 65' Woburn, Massachusetts 01801-63! www.alc-enviro.cc 781.932.941 Fax 781.932.62 ASSOCIATES INC.

June 26, 2002

Mr. Bernard P. Orlan Director, Environmental Health & Safety New York City Board of Education 28-11 Queens Plaza North Long Island City, NY 11101 -4008

Re: Air Sampling for Silica High School of Economics and Finance (M833) 100 Trinity Place New York, New York ATC Project No. 15-19125-0291

Dear Mr. Orlan;

ATC Associates Inc. (ATC) is pleased to provide this report of the results of air sampling .for silica-containing dust conducted on May 18, 25 and 30, 2002, at the referenced school. The New York City Board of Education (BOE) requested this monitoring to evaluate possible contamination in the building.

Scope of Work

ATC collected three (3) samples on each day for respirable dust using pre-weighed 37nini PVC filters connected to size-selective cyclones to remove the larger (non-respirable) particles prior to deposition on the filters. All of the samples were collected indoors. The samples (and one blank on each day) were sent to PSC Analytical Services, Inc., an American Industrial Hygiene Association accredited laboratory in Reading, PA. Analysis for silica was performed by x-ray diffraction according to OSHA Method 142. Copies of the analytical laboratory reports are attached.

Tenzin Namgyal and Wagdi Abdelshahid, Industrial Hygienists of ATC’s New York City office, collected the samples consistent with generally accepted industrial hygiene practices. The results of the sampling represent conditions found on the dates the samples were collected.

Samples were obtained in the following locations; 1st floor Main Lobby, 5tti floor Hallway and 10th floor Hallway.

Results

The results of all of the samples collected on all three days were below the detection limit for silica (<5.0 micrograms per sample).

CITY_21MC100_002870348

NYC-WTC_000214146