Environmental assessment report, 100 Church Street, April 2002

NYC 9/11 Public Portal Document

activities were performed under asbestos abatement conditions. In addition to the Branch clean­ up, Miho performed fine cleaning of the entire interior space and its contents utilizing wet-wipe and HEP A vacuuming protocols. Miho also power-washed the exterior of the building. Rosenwach Tank was retained to clean and flush the two domestic water rooftop house tanks, and G & G was hired to clean the HVAC system. Although TRC did not oversee the initial clean-up of the building, based upon our initial inspection and a review of the TRC wipe sampling data compared to reports from Ambient on pre-cleaning conditions, the performance of clean-up contractors appears to have significantly reduced the dust/contamination in the building caused by the collapse of the WTC. One exception appears to have been the performance of G&G, the first contractor to clean the HVAC.

4.3 Results of Visual Inspection of NYCLD Space A TRC Certified Industrial Hygienist (CfH) conducted a visual inspection of the NYCLD space, the HVAC fan room on the 7®* floor, the ground floor lobby and associated 2"^^ floor HVAC system and other common areas. This visual inspection indicated that the NYCLD office space areas had been cleaned and that minimal visible dust accumulation was present. Such dust as was present was sampled and analyzed, and the results of that work are discussed in Section 4.4 below.

The inspection of the HVAC system including fan units, supply and return air ductwork and return air plenum indicated that visible dust accumulation was present, which was greater than would be expected under normal operations. As a result of TRC’s inspection and surface dust sampling in the HVAC system, as discussed in Section 4.4 below, a HVAC re-cleaning program was recommended and implemented.

4.4 Results of Surface Dust Sampling and Analysis Dust/residue on surfaces in the NYCLD space was sampled and analyzed for asbestos, lead, PCBs, dioxins, and total particulates. Dust on surfaces of the HVAC serving NYCLD spaces was also sampled for asbestos and lead.

4.4.1 Asbestos Surface Dust Sampling and Results

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