NYC-WTC_000199108

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.

April 1,2002

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. 234M ATC Project No. 15-19125-0279

Dear Mr. Orlan:

ATC Associates, Inc. (ATC) is pleased to provide this letter report of air sampling for hydrocarbon compounds conducted on March 12, 2002, at the referenced school. The New York City Board of Education (BOE) requested this sampling at the recommendation of Environ Corp., the consultant to the parents association.

Scope of Work

ATC collected four (4) samples for hydrocarbon compounds (HC) at specified locations. Samples were collected for a minimum of ten (10) hours using activated coconut shell charcoal tubes connected to batteiy-powered sampling pumps at a flow rate of 0.2 liters per minute. Pumps were calibrated before and after each sampling period. Two (2) samples were collected inside the building and two (2) samples were collected outside. One blank tube was also submitted. 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 (NIOSH Methods 1003, 1005, 1022, 1300, 1500, 1501).

Wagdi Abdelshahid and Tenzin. Namgyal, Industrial Hygienists from ATC’s New York City office, conducted the sampling.

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^). 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 results indicate conditions on the day the samples were collected.

The sampling locations were: 1“ floor hallway, D* floor lobby, the west playgrotmd and the roof by the air intake.

CITY_21MC100_003031447

NYC-WTC_000199108