NYC-WTC_000195194

NYC 9/11 Public Portal Document

floor ceiling by the Liberty Street entrance is made of gypsum board. The ceiling on the Cedar Street entrance consists of suspended acoustical tile covered with decorative tin facing. Above the suspended ceiling is a two-foot void space that houses the HVAC system for the establishment. The basement ceiling is a suspended fibrous tile ceiling. The void space above both suspended ceilings and the gypsum ceiling contained both WTC-related and non-WTC- related dust. Asbestos pipe insulation was present in the void space of the basement. Grills, refrigerators, tables and chairs were present on the first floor. The basement contains walk-in refrigerators, preparation tables, stoves, dishwashing areas and dry goods storage. Prior to cleaning, all open and bulk stored food, fibrous ceiling tiles in the basement, and wrap insulation that had surrounded the HVAC systems were disposed.

Cleaning Method - This unit was cleaned using Test 4A and Test 4D. Test 4A consisted of use of an industrial HEPA-filtered vacuum and an AFD. All horizontal surfaces were wet wiped. Test 4D consisted of cleaning of the HVAC system by a subcontractor utilizing standard industry cleaning techniques.

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

Asbestos Before Cleaning Samples - One wipe sample and one bulk sample were collected from the HVAC system. The wipe sample concentration was below the detection limit, however the detection limit was much higher than the other wipe sample detection limit (approximately 300,000 vs. 3,000). The bulk sample was analyzed by PLM and asbestos was not detected.

Post Cleaning Samples (Test 4A) - Eight air samples were collected for asbestos. The air samples were analyzed for PCM TEM AHERA, and PCMe. The PCM results indicate that six of the samples were below the detection limit and all eight samples were below the secondary numeric criterion of 0.01 f/cc. The TEM AHERA results indicate that seven of the samples were below the detection limit and all eight samples were below the numeric criterion of 0.022 S/cc. The PCMe results indicate that all eight of the air samples were below the detection limit and below the primary clearance criterion of 0.0009 S/cc.

Post P* Cleaning, HVAC System - Three air and two wipe samples were collected. The air samples were analyzed for PCM, TEM AHERA, and PCMe. The PCM results indicate that all of the samples were below the secondary numeric criterion of 0.01 ftcc. The TEM AHERA results indicate that two of the samples were below the detection limit and the third was at the detection limit with all three being below the secondary numeric criterion of 0.022 S/cc. The PCMe results indicate that two of the samples were below the detection limit and the third was at the detection limit with all three being below the primary clearance criterion of 0.0009 S/cc.

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

Post P‘ Cleaning Samples, HPAC System - One air sample was collected after the first

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