NYC-WTC_000197674

NYC 9/11 Public Portal Document

Sampling Methodology ATC provided all laboratory analytical services in support of this limited inspection. ATC is certified by the New York State Department of Health’s Environmental Laboratory Accreditation Program to perform lead and related analyses of environmental samples (Laboratory ID Number: 10879). The laboratory utilizes the United States Environmental Protection Agency analysis method number SW846-7420 and the National Institute of Occupationcil Safety and Health method number 7082M.

The lead-in-dust samples were obtained by gently wiping a pre-measured surface area with non-alcohol moistened towelettes. ATC’s representative wore disposable gloves; a new glove was worn with each new sampling procedure, and care was taken to avoid contamination of the towelette and collection vial. Towelettes were then placed into 50ml plastic vials and immediately sealed. The chain of custody form was completed and documents the measurement of the area sampled.

Results of Dust Wipe Sampling Seventeen (17) dust wipe samples were collected from areas indicated to ATC. Laboratory analysis is shown that all dust wipe samples collected from the indicated areas contain lead on floor and windowsill surfaces below the guideline level of 40 pg/ft^ and 250 pg/ff respectively. See laboratory report and chain of custody for more details.

Limits of the limited dust wipe sampling Dust sampling was conducted at NYC-BOE request. The results of this report are applicable for the time the testing was performed. If questions arise concerning lead content in or on components and/or locations not tested by ATC, then additional testing services shcmld be procured. ATC makes no representation or warranty concerning the standards and specifications provided in the HUD Guidelines and the NYC-BOE protocol.

It is our pleasure to provide these limited lead services to New York City Board of Education. If you have any questions regarding this limited lead-in-dust wipe sampling, please do not hesitate to call me at (212) 353-8280 extension #211.

Sincerely, ATCAssociates, Inc.

xYiannis Efstathiou Senior Project Manager

Sluyvesant HS (M477) June 20, 2002

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NYC-WTC_000197676