NYC-WTC_000228297

NYC 9/11 Public Portal Document

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

February 18, 2002

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

Re: Air Sampling for Hydrocarbons P. S. 89M ATC Project No. 15-19125-0297

Dear Mr. Orlan;

ATC Associates, Inc. (ATC) is pleased to provide this report of the results of air sampling for volatile hydrocarbon compounds conducted on February 7, 2002, at the referenced school. The New York City Board of Education (BOE) requested this sampling as part of a program to determine the indoor air quality prior to reoccupancy.

Scope of Work

ATC collected four (4) samples for hydrocarbon compounds (HC) at specified locations. Samples were collected for ten (10) hours using activated coconut shell charcoal tubes connected to battery-powered sampling pumps at a flow rate of 0.2 liters per minute. Pumps were calibrated before and after each sampling period. Three (3) samples were collected from locations outside the building and one (1) was collected inside. One blank tube was also submitted for analysis. The samples were sent to PSC Analytical Services, Inc., an American Industrial Hygiene Association-accredited laboratory in Reading, PA. Analysis was performed by capillary gas chromatography/flame ionization detection (OSHA Method 7).

Each sample was analyzed for a panel of sixteen (16) specific HC compounds. These compounds were; pentane, acetone, methylene chloride, hexane, chloroform, methyl chloroform, benzene, 1,2-dichloroethane, trichloroethylene, toluene, perchloroetyhylene (tetrachloroethylene), chlorobenzene, ethylbenzene, styrene, cumene and xylenes. In addition, two non-identified peaks, total other A-hydrocarbons and total other B-hydrocarbons, were reported. The A- hydrocarbons are those, such as gasoline or light alcohols, with boiling points less than that of benzene (176°F). The B-hydrocarbons are those, such as mineral spirits or petroleum naphtha, with boiling points greater than that of benzene, A copy of the analytical report is attached.

The sampling locations were as follows:

T' floor hallway, playground-north, playground-south and the roof.

CITY_21MC100_002899805

NYC-WTC_000228297