NYC-WTC_000195194

NYC 9/11 Public Portal Document

Post P* Cleaning Samples - Three air samples and five wipe samples were collected after the first cleaning. The results of the three air samples indicate that MMVF was present; w however, all samples were below the primary clearance criterion of 10 S/L. The results of the five wipe samples indicate that MMVF continued to be present in all of five of the samples after the first cleaning; however, the concentrations detected were lower than in the pre-cleaning samples. This indicates that the cleaning techniques were effective at reducing the pre-cleaning concentrations of MMVF.

PAH Before Cleaning Samples - Three pre-cleaning wipe samples were collected. All three samples were below the detection limit. The TEF for each sample was below the primary clearance criterion.

Post P* Cleaning Samples - Four wipe samples were collected after the first cleaning. All w were below the detection limit and the TEF for each sample was below the primary clearance criterion of 300 pg/m^. Since all of the samples were below the detection limit w and the primary clearance criterion after the first cleaning, no additional samples were collected for analysis of PAH. w

Unit 5C - This unit is located on the fifth floor. It is a 968 sq. ft. loft with three separate «r bedrooms facing the WTC. The unit has hardwood floors. Windows were blown in. There was a* significant accumulation of dust in the dwelling. All of the tenant’s personal items were removed * prior to cleaning. W Cleaning Method - This unit was cleaned twice using Test 3 A: an industrial HEPA-filtered vacuum for vacuuming the floors and other surfaces. An AFD was not used during the cleaning process. All horizontal surfaces were wet wiped. This cleaning method was used for the first two w cleaning events. The third cleaning event used Test 3B, which is similar to Test 3 A described above; however, AFDs were used during the third cleaning.

Cleaning Results -’With the exception of asbestos, this unit met the clearance criteria listed in ■r Table 1.0 for each compound after being cleaned three times.

Asbestos Before Cleaning Samples - Three micro vacuum and four wipe samples were collected for analysis of asbestos. These samples indicate that asbestos was present in the unit prior to cleaning. All three micro vacuum samples, as well as all four wipe samples, detected chrysotile above the detection limit.

Post P‘ Cleaning - Three air samples, three micro vacuum samples, and five wipe samples w were collected. The three air samples were analyzed using PCM and PCMe. The PCM results indicate that two of the samples were below the secondary numeric criterion of 0.01 f/cc. The third slightly exceeded the primary clearance criterion with a result of 0.015 f/cc. The PCMe analysis could not be conducted due to overloading of particulate material. Due to inconclusive PCMe results, a second cleaning was conducted.

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