Environmental assessment report, 100 Church Street, April 2002

NYC 9/11 Public Portal Document

TRC had a Certified Industrial Hygienist (CIH) visually inspect the entire NYCLD space, common spaces that NYCLD employees enter in the course of their work in the building, and “hidden” spaces that serve the area, including the HVAC and other mechanical spaces. This inspection included accessible areas of the HVAC system serving the NYCLD spaces. A boroscope with a self-contained light source was utilized as needed to assist in the visual inspection of the ductwork.

3.4 Dust Sampling and Analysis TRC conducted wipe and microvacuum sampling of residual dust to confirm the effectiveness of the response actions. The following identifies the sampling and analysis that was conducted along with associated standards and guidelines:

Asbestos - American Society for Testing and Materials (ASTM) Test Method D5756-95 Microvacuum Sampling and Indirect Analysis (Filter Sample Analysis) of Dust by Transmission Electron Microscopy (TEM) for Asbestos Structure Number Concentration. A post-cleaning individual sample target concentration of less than 10,000 structures per square centimeter (str/cm" l and a geometric mean concentration of 1000 str/cm^ was established for this proj ect.

Lead - United States Department of Housing and Urban Development (HUD) Wipe Sampling Guidelines. A post-cleaning lead wipe target concentration of 40 micrograms per square foot (ug/ft^) for occupied spaces and 400 ug/f1“ for non-occupied spaces was established for this project.

• PCBs - United States Environmental Protection Agency (USEPA) Document EPA 560/5-85- 026 Verification of PCS Spill Cleanup by Sampling and Analysis. The USEPA clearance criteria of 10 micrograms per 100 square centimeters was used for this project.

• Total Particulates - Modified National Institute for Occupational Safety and Health (NIOSH) Sampling and Analytical Method 0500. Dust loading inside computer equipment was compared to non-impacted control concentrations.

Dioxin - USEPA Document EPA-Methods 8290 and 1668. No clearance concentrations are established for surface dioxin concentrations. Therefore, TRC incorporated wipe data into a site specific human health risk assessment.

• Biological - American Industrial Hygiene Association Sampling Guidelines. Data was compared to New York City Department of Health (NYCDOH) guidelines.

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