EPA interim final report on WTC background study, April 2003

NYC 9/11 Public Portal Document

Table of Contents

EXECUTIVE SUMMARY 1

1.0 INTRODUCTION 6

2.0 BACKGROUND AND PROJECT DESCRIPTION 6 2.1 Background ................................................ 6 2.2 Purpose/Objective ...................................... 6 2.3 Project Description...................................... 7 2.4 Project Team/Responsibilities............ ........ 8 2.5 Data Usage.................................................. 8

3.0 SAMPLING APPROACH/RATIONALE 9 3.1 Selection of Sampling Area Location ................................ 9 3.2 Selection of Building Types and Obtaining Access .......... 9 3.3 Selection Criteria for Number of Buildings, Residences and Common Space Sampled.................................................... 10 3.4 Selection of Contaminants of Potential Concern................ 10

4.0 SAMPLING METHODOLOGY .... 11 4.1 Sampling Procedures.............................. ....11 4.1.1 Indoor Air Sample Collection........ .... 12 4.1.2 Microvacuum Sample Collection .. .... 12 4.1.3 Wipe Sample Collection................ ....13 4.1.4 Bulk Dust Sample Collection........ ....13 4.1.5 Quality Control Samples................ ....13 4.2 Sampling Equipment.............................. ....15 4.2.1 Air Sampling Equipment .............. ....15 4.2.2 Microvacuum Sampling Equipment .... 15 4.2.3 Wipe Sampling Equipment ... 16 4.2.4 Bulk Sampling Equipment............ ....16 4.3 Sample Numbering/Identification.......... ....16 4.4 Sample Shipment..................................... ....16 4.5 Data Validation and Reporting .............. ....17 4.5.1 Validation....................................... ....17 4.5.2 Verification..................................... ....17

5.0 SAMPLING PROTOCOL DEVIATIONS 18

6.0 ANALYTICAL RESULTS AND DEVELOPMENT OF BACKGROUND CONCENTRATIONS 19 6.1 Methods 19 6.2 Results and Development of Background Concentrations ........ 22 6.2.1 Asbestos 22

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NYC-WTC_000145871