Ambient air sampling report for 105 Duane Street, Feb 2002

NYC 9/11 Public Portal Document

I Tribeca Tower —105 Duane Street ATC Project No.: 09622-0014 Related Management Company, L.P. February 11, 2002 I Page 1

General ATC Associates Inc. (ATC) was retained by the Related Management Company, L.P. in I response to air quality concerns at Tribeca Towers following the collapse of the World Trade Center buildings on September 11, 2001. Addressing the concerns ATC conducted interviews with building maintenance personnel, performed a visual inspection of the ventilating and air u conditioning system air intakes and a walkthrough visual inspection of residential units and common areas. Ambient air samples were collected for fiber analysis via Transmission Electron Microscopy (TEM). Additionally ATC provided a scope document for and conducted spot I checks of a cleaning of the house supply air system and building exterior.

I Interview with Building Maintenance Personnel and Visual Inspections Based upon ATC's discussion with the resident manager and our observations, ATC concludes that building management actions and subsequent loss of power successfully shut down the n house air conditioning systems minimizing dust intrusion into the HVAC system, and that at the time of our inspection the house supplied HVAC system was free of dust accumulations that can be attributed to the collapse of the World Trade Center Buildings. u

ATC visually inspected 406 units for accumulated dust and/or debris consistent with material that from ATC's experience emanated from the collapse of the World Trade Center Buildings. Thirty-five units were inaccessible or the occupants refused access and were not inspected. 1111 Of the 406 units inspected, ATC did not observe any dust and/or debris accumulations that in ATC's opinion was consistent with widespread deposition of material that emanated from the

I collapse of the World Trade Center Buildings. However, ATC observed adjacent to open windows in four units, limited dust accumulations (no debris) although inconsistent with material that emanated from the collapse of the World Trade Center Buildings present nonetheless.

I Ambient Air Sampling — Transmission Electron Microscopy

I On October 24, 25, November 7, 21, December 5, 19, and January 2 & 3, ATC collected 65 common area and 157 residential units samples as requested by the resident to ascertain the presence or absence of airborne asbestos. Units sampled are listed below by sampling date. All samples were collected and analyzed in accordance with the AHERA Transmission Electron I Microscopy (TEM) method as set forth at 40 CFR Part 763, Subpart E, Appendix A which provides resolution down to 0.5µ. structure size. Of the total 222 samples collected, a single asbestos structure was detectable on only two samples. I In the absence of a specific ambient air standard, ATC has selected as a criteria for acceptable ambient air sample sets, the AHERA re-occupancy requirement following an asbestos I abatement action of an average of less than 70 asbestos structures per square millimeter (<70 s/mm2) per sample set. This criteria has been selected because the AHERA requirement is the most stringent reoccupancy requirement available, and has been designed to be protective of children following an asbestos abatement project. Based upon analytical sample results for all samples recording levels well below the AHERA n

clearance requirement, it is ATC's opinion that the ambient air samples collected throughout the I building are representative of the ambient conditions at the time of testing and that the areas tested meet an acceptable criterion for re-occupancy

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