Chain of custody form for DEP environmental samples, 2001

NYC 9/11 Public Portal Document

was reduced after the first cleaning, no additional samples were collected for analysis of MMVF.

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

Post Cleaning Samples - Four wipe samples were collected after the first cleaning. All of the samples were below the detection limit. The TEF for each sample was below the primary clearance criterion of 300 pg/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 3C - This unit is located on the third floor. It is a 655 sq. ft. loft with two bedrooms facing the WTC site. The unit has hardwood floors with no carpet. The unit presented significant accumulation of dust in the dwelling. The windows were blown in. The majority of personal items were disposed of prior to cleaning.

Cleaning Method - This unit was cleaned using Test 1 A: a Craftsman® shop vacuum and a Eureka® upright vacuum with no HEPA filter. An AFD was not used. This method was used for the first two cleaning events. For the third cleaning event the method was changed to Test 3B: an industrial HEPA filtered vacuum and an AFD. All horizontal and vertical surfaces were wet wiped in conjunction with each method.

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

Asbestos Before Cleaning Samples - Four micro vacuum and four wipe samples were collected for asbestos. These samples indicate that asbestos was present in the unit prior to cleaning. AU four of the micro vacuum samples detected chrysotile. Three of the four wipe samples detected chrysotile; one also detected amosite. The fourth wipe sample was below the detection limit.

Post Cleaning Samples - Three air, four micro vacuum, and five wipe samples were collected for asbestos. The PCM and PCMe analyses could not be conducted due to overloading of particulate matter on the filters.

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

Two of the five wipe samples were below the detection limit, although one of these samples did detect chrysotile. Results of the remaining three samples were above the detection limit and similar to or lower than the pre-cleaning samples.

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