NYC-WTC_000202331

NYC 9/11 Public Portal Document w—■

TC 104 East 25th st., 10th Floor New York, New York 10010 www.atc-enviro.com 212.353.8280 A S SO C I A T E S I N C . Fax 212.353.8306

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 High School for Leadership and Public Service (M894) ATC Project No. 15-19125-fl29a

Dea / ATC for p Septt samples on ration I! (DOI C ffTc ng.

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The SI cV. d solvent were Pace) of Miime rrmed by modifi phy/high resolut.

Tenzin .,_x«Bj^r, mQUstrfal 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.

WIPE SAMPLING RESULTS

ATC submitted three (3) wipe samples for PCDDs/PCDEs (plus one blank) to Pace for analysis. A copy of the laboratory analysis report is provided in the Attachment. The floor locations sampled were: Main Lobby, 5^ Floor Lobby and the 10^ Floor Lobby. The area of each sample was one square meter (1 m2).

Each sample was analyzed for sixteen (16) PCDD/PCDF isomers. The results for each isomer were then converted to 2, 3, 7, 8 -tetrachloro-dibenzo-p-dioxin (2, 3, 7, 8-TCDD) equivalents by multiplying by an established equivalency factor.

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CITY_21MC100_003272188

NYC-WTC_000202331