NYC-WTC_000195194

NYC 9/11 Public Portal Document

w an AFD. 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 one time.

Asbestos Before Cleaning Samples - Two micro vacuum and five wipe samples were collected for w analysis of asbestos. These samples indicate that asbestos was present in the unit prior to cleaning. The two micro vacuum samples detected chrysotile above the detection limit. Three of the five wipe samples were below the detection limit, although four of the five wipe samples detected either chrysotile or amosite. w

Post P‘ Cleaning Samples - Three air, two micro vacuum and five wipe samples were collected for asbestos. The samples were analyzed for PCM and PCMe. The PCM results w indicate all three air samples were below the secondary numeric criterion of 0.01 fZcc. The PCMe results indicate that all three of the samples were below the primary clearance w criterion of 0.0009 S/cc.

The results of the two micro vacuum samples indicate that asbestos was present at levels somewhat similar to those observed before cleaning.

The results of the five wipe samples indicate that asbestos was below the concentrations observed in the pre-cleaning samples and was below the detection limit for all samples.

Dio?dn Before Cleaning Samples - Four wipe samples were collected and analyzed for dioxin. The results indicate that dioxin was not present and that the TEQ concentration for all samples 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 there was dioxin present; however, the TEQ concentration was below the primary clearance criterion of 4 ng/m^ and similar to pre­ cleanup concentrations.

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

Post Cleaning Samples - Two air samples were collected after the first cleaning. Gypsum was not detected above the detection limit of 0.016 mg/m’ in the air samples.

Lead Before Cleaning Samples - Two micro vacuum samples and four wipe samples were collected. Lead was detected in both micro vacuum samples and two of the four wipe samples at concentrations above the comparison value or primary clearance criterion of 25 gg/ft^. The micro vacuum samples exceeded the comparison value, ranging fi-om 27.1 pg/ft^ to 49.1 pg/ft2, and the two wipe samples exceeded the primary clearance criterion, ranging from 25.3 pg/fV and 32.1 p^ft^

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