NYC-WTC_000195194

NYC 9/11 Public Portal Document

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 once.

Asbestos Before Cleaning Samples - Pre-cleaning wipe samples were collected for asbestos. The results for these samples indicate that asbestos was present in the unit prior to cleaning. Two of the five wipe samples were below the detection limit, although one of these samples had chrysotile detected. The remaining three samples had chrysotile detected above the detection limit.

Post P‘ Cleaning - Three air and five wipe samples were collected. The three air samples were analyzed using PCM and PCMe. The PCM results were all below the secondary numeric criterion of 0.01 f/cc. The PCMe results for each sample were below the primary clearance criterion of 0.0009 S/cc and were reported as below the detection limit.

The results for the five wipe samples that were collected indicate that asbestos was present in two of the five samples; however one of these samples was below the detection limit. The remaining three samples were below the detection limit.

Dioxin Before Cleaning Samples - Four pre-cleaning wipe samples were collected and analyzed for dioxin. The results indicate that there was dioxin present; however, the TEQ concentration for each sample was below the primary clearance criterion of 4 ng/m^.

Post P‘ Cleaning Samples - Four post-cleaning wipe samples were collected and analyzed for dioxin. The results indicate that the TEQ concentration for each sample was below the primary clearance criterion of 4 ng/m^.

Gypsum Before Cleaning Samples - Pre-cleaning air samples were not collected.

Post P* Cleaning Samples - Two air samples were collected after the first cleaning. Gypsum was not detected in any sample.

Lead Before Cleaning Samples - Four pre-cleaning wipe samples were collected. The results indicate that lead was detected in three of the four wipe samples with two samples exceeding the primary clearance criterion of 25 pg/ft^ One sample was slightly over the primary clearance criterion with a result of 30 pg/ft\ while the second was twice the primary clearance criterion with a result of 50 pg/ft^.

Post P‘ Cleaning Samples - Two air samples and four wipe samples were collected after the first cleaning. The two air samples were above the detection limit but below the primary clearance criterion of 1.0 pg/m^. Three of the four wipe samples were below the detection limit. The fourth wipe sample was above the detection limit but below the

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