Air sampling correspondence, 20 Dey Street, Feb 2002

NYC 9/11 Public Portal Document

ro MILLENNIUM HILTON HOTEL

ASBESTo rtyffkt ING

Samples were placed into leak-tight plastic sample containers, carefully noting the location and material sampled and stored for transport to the laboratory facility. A chain-of-custody and analysis requested was initiated for all samples collected.

Samples were analyzed by Polarized Light Microscopy (PLM) in accordance with the Environmental Protection Agency's Interim Method for the Detection of Asbestos in Bulk Insulation Samples (EPA- 600JM4-82020, December 1982) and the McCrone Research Institute's The Asbestos Particle Atlas as method reference.

The Indoor Air Quality Test for asbestos was performed utilizing the "Measuring Airborne Asbestos Following an Abatement Action" procedure issued by US EPA (November 1985). The aggressive sampling procedure was employed: before the sampling pumps were started the forced air equipment was used to direct exhaust air against all walls, floors, ledges and other surfaces in the work area for at least 5 minutes per 1,000 square feet of the floor area; then immediately after the low speed air fans were turned on pointed toward the ceiling. Total of 1,250 liters of air was taken at each point of sampling as required by 15 RCNY — New York City Asbestos Control Program Rules and Regulations. The air test samples were taken using 25 mm cassette with MCE filters with 0.45+5 µIII pore size.

Air samples were analyzes and reported in accordance with the Electron Microscopy Methods set forth at 40 CFR part 763, Subpart E, Appendix A.

6.0 CONCLUSIONSIRECOMMENDATIONS

Based on our observation at the site and the laboratory analysis results, we have determined asbestos fiber concentration in the Millennium Hilton Hotel building exceeds the present standard set forth by US EPA and NYC DEP. The inspection also confirms presence of asbestos more than 1% by weight in the dust and debris throughout the building. Based on concentration of asbestos fibers present, we recommended that elevators shafts, stairways and mechanical areas in the building should be HEPA vacuumed and wet clean. All porous materials in the building such as carpeting, draperies, linens and textured wall coverings, should be removed and disposed of as asbestos contaminated waste. After completion of the removal and following cleaning work the Hotel's interior should be subject to clearance air sampling.

NYC-WTC 000103738