NYC-WTC_000196569

NYC 9/11 Public Portal Document

104 East 25th St, 10th Floor New York, New York 10010 WWW atc-enviro com 212 353 8280 Fax 212 353 8306 ASSOCIATES INC.

November 25, 2002

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

Re: Wipe Samples for Dioxins P. S. 124 Manhattan ATC Project No. 15-19125-0350

Dear Mr .Orlan

ATC Associates Inc (ATC) is pleased to provide this report of the results of the wipe-samples for polychlorinated dibenzo-p-dioxins (PCDDs)and dibenzofurans (PCDFs) collected on . September 12, 2002, at the referenced location. The New York City Department of Education (DOE) requested these samples to evaluate possible contamination in the school building

Scope of Work

The samples were collected using gauze pads and hexane as a solvent The solvent was provided and samples were analyzed by Pace Analytical Services, Inc (Pace) of Minneapolis, MN, a laboratory experienced in dioxin analysis. The analysis was performed by modified EPA Method 8290 using combined capillary column gas chromatography/high resolution mass spectrometry

Tenzin Namgyal, Industrial Hygienist of ATC’s New York City office, collected the samples consistent with generally accepted industrial hygiene practices There were inherent limitations created by constraints of time, operational and work practice variability, variations in contaminant concentrations, and sampling and analytical accuracy The results of the sampling represent conditions found on the date the samples were collected

Results

ATC submitted three wipe samples for PCDDs/PCDFs (plus one blank) to Pace for analysis. Samples were taken from representative floor areas throughout the building. The sample area for each sample was one square meter (1 m2) The areas sampled were;

• Lobby-Main Entrance • Floor Hallway by Room 222, • 3rd Floor Hallway by Room 307.

CITY_21MC100_003041801

NYC-WTC_000196569