Document page fragment, DEP Box 54, 2003

NYC 9/11 Public Portal Document 04/23/2003 11:31 18568589551 EMSL ANALYTICAL PAGE 83

EMSL Analytical, Inc. 107 Haddon Ave., Westmont, NJ 08108

. I Order ID:040305286 Attn: Andrew/ M.N. Khan Customer 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/NYCDEP114 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

Respirable Dust Airborne Silica Sample Sample Silica Silica % Analytical Sample ID Identification Particle Volume Weight Conc. Weight Conc. Silica Sensitivity IA (L) (mg) (mg/m3) (mg) (mg/m3) (mg/n?)

MB13687-3QC I OTH PLR DINING Quartz 408 0.601 1.4730 0.0070 0.0172 1.2 0.0110 STANDARD 0.030Q uartz 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 sample set. 3. Results are not field blank corrected.

Disclaimer: The laboratory can only verify the concentration of silica on the filter and not the final concentration due to data obtained by non-laboratory personnel. In the absence of a bulk dust sample neither the specific forms of crystalline silica m r 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 that is calculated from the lowest reproducible amount of specific mineral detectable by the instrument

Anant Samudra, Ph.D. Analyst Stephen Siegel, CIH- Lab Manager Or other approved signatory AIHA Accredited - Laboratory ID #100194 ,Page 3 of 3

NYC-WTC 000132104