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NYC 9/11 Public Portal Document

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EMSL Analytical, Inc. 107 Haddon Ave., Westmont, NJ 08108 EMSL Order 10:040305286 Atta: Andrew/ M.N. Khan Custuiiici ID: JLCC50 JLC Environmental Consultants, Inc. Customer PO: 200 Park Ave South, Suite 1001 Date Received: ' 04/05/03 12:23 AM New York, NY 10003 Fax: 212-420-6092 EMSL Order; 040305286 Project: #03-2744/NYCDEP—114 Liberty ST EMSL Project ID: Report Date: 04/14/03 Date Analyzed; 04/14/03

Silica, Crystalline Analysis Performed X-Ray Diffraction (XRD) Modified NIOSH Method 7500, Issue 3,1/15/98

I Respirable Dust Airborne Silica I Sample Sample SiUca Silica % Analytical Sample ID Identification Particle Volume Weight Cone. Weight Cone. SiUca Sensitivity ID (L) (mg) (mg/m’) (mg) (n^m^ (mg/m’)

MB13687:3QC lOTHFLR DINING Quartz 408 0.601 1.4730 0.0070 0.0172 1.2 0.0110 STANDARD 0.03QQ pugte N/A N/A N/A 0.025 N/A N/A N/A LAB BLANK Quartz 0 N/A N/A 0.0045 N/A N/A N/A

Notes: 1. Bulk sample not submitted with sample set. 2. Discernable field blank not submitted with sanple set. 3. Results are not field blank corrected.

Disclaimer; The laboratory can only verify the concentration of silica on die filter and not the final concentration due to data obtained by non-laboratoiy personnel. In the absence of a bulk dust sample, neither the specific forms of crystalline sifica nor the interfering species can be fully determined. Hence, the amount for each phase, if anticipated, will be analyzed based on primary, secondary, and/or tertiary peak data with comparison to calibration curves of known standards. It should be noted that air samples are meant for only quantifying silica (or a mineral phase) which must first be identified from a bulk dust sample. “<” means less than the stated value. The lowest reportable value is equivalent to the Analytical Sensitivity diat is calculated from the lowest reproducible amount of specific mineral detectable by the instrument.

Anant Samndra, Ph.D, Analyst Stephen Siegel, G Manager Or other approved signatory

AIHA Accredited - Laboratoty ID #100194 Page 3 0/3

NYC-WTC_000155057