NYC-WTC_000175347

NYC 9/11 Public Portal Document

104 East 25th St., 10th Fl New York. New York 10010 www.atc-enviro.com 212.353.8280 Fax 212.353 8306 ASSOCIATES INC. t.

September 19, 2002

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

Re: Air Sampling for Mercury Vapor Murray Bergtraum High School (M520) ATC Project No. 15-19125-0351

Dear Mr. Orlan:

ATC Associates, Inc. (ATC) is pleased to provide this report of the results of air sampling for mercury (Hg) vapor conducted on September 11, 2002, at the referenced school. The New York City Department of Education (DOE) requested this sampling to verify that acceptable indoor air quality is being maintained.

Scope of Work

ATC collected three (3) samples for Hg vapor using Carulite® (Hydrar) tubes connected to battery-powered sampling pumps calibrated to collect 0.2 liters of air per minute. The samples were sent to PSC Analytical Services, Inc., an American Industrial Hygiene Association- accredited laboratory in Reading, PA. One blank tube was also submitted. Analysis was performed by means of a mercury vapor analyzer according to NIOSH Method 6009. A copy of the analytical laboratory report is attached.

Tenzin Namgyal, Industrial Hygienist and Sonny Ramlal, Environmental Technician from ATC’s New York City office, conducted the sampling consistent with accepted industrial hygiene practices. The results represent the conditions on the day the samples were collected.

The sampling locations were: P' floor Main Lobby, 3"* floor Hallway by Room 339 and 5“’ floor Hallway by Room 518.

Results

Mercury (Hg) was detected in these samples at levels that were indistinguishable from that detected in the blank.

The established regulatory value for mercury (O.lmg/m’) is intended for industrial workplace exposures and is not generally applicable to office/school settings. There are no standards for mercury in indoor air in non-industrial situations. The EPA has no standard or guideline for mercury vapor in ambient air.

CONFIDENTIAL, CITY_21MC100_003422336 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

NYC-WTC_000175347