Chain of custody form for DEP environmental samples, 2001

NYC 9/11 Public Portal Document

Unit 3B - This unit is located on the third floor. It is a 968 sq. ft. loft with three bedrooms facing Cedar Street. The unit has hardwood floors. No windows were blown in and the unit presented minimal dust accumulation, with the exception of the baseboard heating units, which contained visible dust. All of the tenant’s personal items remained in the unit and were cleaned.

Cleaning Method - This unit was cleaned using the Scope A cleaning procedures; industrial HEPA-filtered vacuum of all surfaces. An AFD was used. All surfaces were wet wiped. This cleaning method was used for each cleaning event in this unit.

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

Asbestos Before Cleaning Samples - Two air, three micro vacuum and four wipe samples were collected for asbestos. These samples indicate that asbestos was present in the unit prior to cleaning. The two air samples that were collected were analyzed using PCM and PCMe. One PCM result was below the secondary numeric criterion of 0.01 ffcc. The other PCM result was above the secondary numeric criterion. The PCMe results indicate that both samples were below the detection limit and below the primary clearance criterion of 0.0009 S/cc. Two of the three micro vacuum samples detected chrysotile. The third sample was below the detection limit. Three of the four wipe samples were below the detection limit. The fourth one detected chrysotile at a concentration slightly above the detection limit.

Post P‘ Cleaning - Three air, three micro vacuum and five wipe samples were collected to evaluate if additional cleaning events were necessary. The three air samples that were collected indicated that all three PCM results were below the secondary numeric criterion of 0.01 ficc and that the TEM AHERA and PCMe analyses could not be conducted due to overloading of particulate material. Due to inconclusive PCMe results, a second cleaning was conducted.

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

The results for the five wipe samples that were collected indicate that asbestos was present in all five of the samples at slightly higher concentrations than the pre-cleaning samples. One of the five samples in which asbestos was detected was below the detection limit.

Post 2”"^ Cleaning - Three asbestos air samples were collected after the second cleaning. The samples were analyzed for PCM, TEM AHERA, and PCMe. Two of the three PCM results were below the detection limit; all three were below the secondary numeric criterion of 0.01 fi'cc. All three TEM AHERA results were below the detection limit and below the secondary numeric criterion of 0.022 S/cc. All three PCMe results were below the detection limit and below the primary clearance criterion of0.0009 S/cc. All of the air asbestos results after the second cleaning were at lower concentrations than the pre­ cleaning samples and the samples collected after the first cleaning. This indicates that the cleaning techniques used were efficient at removing asbestos to levels that were below

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