PCDD/PCDF wipe sample results, March 21, 2002

NYC 9/11 Public Portal Document

104 East 25th St., 10th Floor fA New York, New York 10010 www.atc-enviro,com 212.353.8280 Fax 212.353.8306 ASSOCIATES INC.

March 21. 2002

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

Re: Wipe Samples for Dioxins High School for Leadership and Public Service (894M) ATC Project No. 15-19125-0290

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 February 14, 2002, at the referenced location. The New York City Board of Education (BOE) requested these samples to evaluate possible contamination in the school building.

SCOPE OF WORK

Wagdi Abdelshahid, Industrial Hygienist of ATC’s New York City office, collected the samples on all three days.

The samples were collected using gauze pads and hexane as a solvent. The pads and solvent were 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.

The sampling was performed 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 dates the samples were collected.

The New York State Department of Health (NYSDOH) established guidelines for dioxin for the re-occupancy of the Binghamton State Office Building following a PCB fire. The N’YSDOH guideline for dioxin on surfaces is 25 nanograms per square meter (25 ng/m^).

CONFIDENTIAL, CITY_21MC100_003432109 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

NYC-WTC_000175652