NYC-WTC_000195194

NYC 9/11 Public Portal Document

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

Unit - This unit is located on the fourth floor. It is a 655 sq. ft. open loft that faces the WTC site. The windows were blown in and there was significant dust accumulation in the dwelling. The unit has hardwood floors and no carpet. All personal possessions to be retained by the tenant were vacuumed and bagged.

Cleaning Method - This unit was cleaned using Test 1 A; a Craftsman® shop vacuum and a Eureka® upright vacuum for vacuuming the floors and other surfaces. No HEPA or AFD was used during the cleaning process. In addition, all horizontal surfaces were wet wiped.

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

Supplemental Sampling Activities - The air samples collected for PAH analysis were taken for reference purposes only. These samples are discussed in the PAH section below.

Asbestos Before Cleaning Samples - Pre-cleaning micro vacuum and wipe samples were collected for asbestos. These samples indicate that asbestos was present in the unit prior to cleaning. All four of the micro vacuum samples detected chrysotile, and one of the four micro vacuum samples detected amosite. Three of the four wipe samples detected chrysotile; however, one of these samples was below the detection limit. The fourth wipe sample did not detect chrysotile and was below the detection limit.

Post P‘ Cleaning Samples - Three air samples, three micro vacuum samples, and five wipe samples were collected for asbestos. The samples were analyzed using PCM, TEM AHERA, and PCMe. The PCM analysis could not be conducted due to overloading of particulate material. The TEM AHERA results were above the detection limit but were below the secondary numeric criterion of 0.022 S/cc. Two of the three air samples analyzed using PCMe were below the primary clearance criterion of 0.0009 S/cc. The third air sample detected chrysotile and was present at the primary clearance criterion of 0.0009 S/cc. Since the primary primary clearance criterion was met, no additional cleaning was required.

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

The results of the five wipe samples indicate that asbestos was present above the detection level in one of the five samples. The concentrations were lower than in the pre-cleaning concentrations.

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