NYC-WTC_000195194

NYC 9/11 Public Portal Document

and determined to be invalid due to an equipment malfunction which resulted in the collection of a volume of air significantly lower than the other four samples. It should be noted that the other four post-2nd cleaning air samples, and the three post-1st cleaning air samples were below the applicable health-based benchmark.

PAH Before Cleaning Samples - Three pre-cleaning wipe samples were collected. Two of the three samples were below the detection limit. The calculated TEF for these two samples was below the primary clearance criterion. Twelve PAH compounds were detected in the third sample. The calculated TEF for this sample exceeded the TEF of 300 pg/m’ with a value of 1,046.6 pg/m^.

Post Cleaning Samples - Four post-cleaning wipe samples were collected. All four samples were below the detection limit. The TEF for each sample was below the primary clearance criterion of 300 gg/m^. This indicates that the cleaning techniques used were effective in reducing the PAH pre-cleaning concentrations.

Unit 3D - This unit is located on the third floor. It is a 968 sq. ft. loft with three bedrooms, facing the WTC site. The unit has hardwood floors with no carpet. This unit presented a significant accumulation of dust in the dwelling. Its windows were blown in. The majority of personal items, with the exception of three pieces of hardwood furniture, were disposed of prior to cleaning.

Cleaning Method - This unit was cleaned using Test 1 A: a Ridgid® shop vacuum and a Hoover® upright without a HEPA filter. AFDs were not used during cleaning. All horizontal surfaces were wet wiped. This cleaning method was used for each cleaning event.

Cleaning Results - This unit met the clearance criteria listed in Table 1.0 for each compound after being cleaned twice.

Asbestos Before Cleaning Samples - Three micro vacuum and five wipe samples were collected for asbestos. These samples indicate that asbestos was present in the unit before cleaning. All three of the micro vacuum samples detected chrysotile, and four of the five wipe samples detected chrysotile. The remaining sample was below the detection limit.

Post P‘ Cleaning Samples - Three micro vacuum, five wipe samples and three air samples were collected for asbestos.

All three of the air samples, which were analyzed using PCM, TEM AHERA, and PCMe, could not be analyzed due to overloading of particulate material. Due to this situation, a second cleaning was conducted.

The results of the three micro vacuum samples indicate that asbestos was present at levels lower than those observed before cleaning. One of the samples was below the detection limit.

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