NYC-WTC_000227563

NYC 9/11 Public Portal Document 104 East 25th St., 10th Floor New York, New York 10010 wwwatc-enviro.com 212.353.8280 Fax 212.353.8306 ASSOCIATES INC.

March 30, 2002 N.Y.C. Board of Education 28-11 Queens Plaza North 14584-0865 Long Island City, NY 11101

Attn: Mr. Bernard Orlan

Re: Report of TEM Analysis

Dear Mr. Orlan:

Following are the results of transmission electron microscopy (TEM) analysis of air samples from our Group No. 7275:

Project Name: H.S. of Economics & Finance, 100 Trinity Pl., NY, NY Location: Entire Building Samples received: 03/30/02

These results will confirm and document the data transmitted today to Mr. Mark Terjesen, Project Manager, of our office. The analyses were performed in strict conformance with the methodology of the TkHERA Final Rule (40 CFR Part 763, Appendix A to Subpart E, October 30, 1987) for clearance of abatement sites.

The results of the sample analyses are as indicated on the attached document.

Copies of the bench sheets are also included as stipulated by AHERA. Nuclepore TEM cassettes. Lot No. 98116617, were used. Results reported as Struct/cc are a function of air volume collected in the field and are, as such, not verifiable by this laboratory. This report may be reproduced only in its entirety and not without prior permission of this laboratory. If post-abatement inside samples pass, the response action may be considered to have been completed. The analyses were supervised by Dr. Michael A. Gorycki, Director of Electron Microscopy.

We are pleased to note that our TEM lab has received full accreditation from NVLAP, as is currently required for recognized analysis of TEM air samples for AHERA projects, and also approval under the NY State DOH ELAP program. These analyses were performed by ATC d/b/a ATC Associates Inc. Please contact me regarding any questions relating to these materials.

Very truly yours,

Michael A. Gorycki, Ph.D. Director of Electron Microscopy

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NYC-WTC_000227563