NYC-WTC_000195194

NYC 9/11 Public Portal Document

numeric criterion and the other two could not be analyzed due to particulate overloading of the filter. The TEM AHERA results were below the secondary numeric criterion for two samples. The third sample could not be analyzed due to particulate overloading of the filter. Of the three air samples analyzed using PCMe, one sample could not be analyzed due to overloading of particulate material. The other two samples were below the primary clearance criterion of 0.0009 S/cc.

The results of the four micro vacuum samples indicate that asbestos was present at levels generally lower than those observed before cleaning. One of the samples was identified as non-detect.

The results of the five wipe samples indicate that asbestos was present in all but one sample; however, two of the samples were identified as non-detect. One of the non-detect samples had an elevated detection limit due to the presence of non-asbestos particulate matter.

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

Gypsum Bejbre 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 above the detection limit for either sample.

Lead Before Cleaning Samples - Four micro vacuum samples and three wipe samples were collected. Lead was not detected in any of the micro vacuum samples. One of the wipe samples was below the detection limit and one wipe sample was below the primary clearance criterion of 25 gg/ft^. The third wipe sample exceeded the primary clearance criterion at 38.9 gg/ft^.

Post Cleaning Samples - Two air samples, four micro vacuum samples, and four wipe samples were collected after the first cleaning. The two air samples were below the primary clearance criterion but were qualified as rejected, due to field blank contamination. The results of the micro vacuum and wipe samples show that, while two of the micro vacuum and two of the wipe samples exceeded the detection limits, all samples met the primary clearance criterion and the comparison values for lead after the first cleaning.

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NYC-WTC_000195242