NYC-WTC_000210616

NYC 9/11 Public Portal Document

107 ffaddon Avenue 4 EMSL EMSL Analyticalj Inc.- Westmont, NJ. 08108

(856) 858A800 10/2/01 Attention: Chris Gerber URS 200 Orchard Ridge Drive Suite 101 Gaithersburg, MD. 20878

Project: #89FUSPS035/ Peck Slip Station RetNomber: 360100272

Silica Analysis Performed by X-Ray Diffraction (XRD) Method NIOSH 7500 I Nuisance Dust Airborne Silica Sample Sample SUica Silica % Analytical Sample ID Identification Particle ID Volume Weight Cone, Weight Cone. Silica Sensitivity (L) (mg) (mg/m*) (mg) (mg/m’) (mg/ni^)

2P1S1 Quark 1000 0.190 0.1900 <0.004 <0.0200 N/A 0.0200 2P2S2 Quarfe 1250 0.270 0.2160 <0.004 <0.0160 N/A 0.0160 2P3S3 Quark 1200 0.150 0.12S0 <0.004 <0.0167 N/A 0.0167 2P4S4 Quartz 1300 0.000 0.0000 <0.004 <0.0154 NZA 0.0154 2P5S5 Quartz 1300 0.200 0.1S38 <0.004 <0.0154 N/A 0.0154

Std.#3 0.008 mg Quartz D.ooa

Bulk Analysis: Sample ID Sample Description Silica Forms Identified Bulk Not Submitted

M. ^'ar^as & J/blewton 2S September, 200i Analyst Date of/Analysis

Disclaimer. The laboiswry can only verify the cofiwnintioii ofsilica co the Siterand not the final concentnifa’on due to data ohtained bj' noo-laboratcry personnel. In the absence ofa bulk dost sample, the specific form of crystalline silica can not be determined. Hence, alpha-quartz, the most prevalent form ofciystalline silica, will be assumed.

CITY_21MC100_002352499

NYC-WTC_000210616