Chain of custody form for DEP environmental samples, 2001

NYC 9/11 Public Portal Document

criterion of 10 S/L. This indicates that the cleaning method was able to reduce the pre­ cleaning concentration of MMVF in the HVAC system.

Post Cleaning Samples (Test 4A) - Eight air samples were collected. All sample concentrations were below the primary clearance criterion of 10 SZL. Six of the eight samples were below the detection limit.

Total Dust Before Cleaning Samples - There were no samples collected before cleaning.

Post Jst Cleaning Samples, HVAC System - The results for the micro vacuum sample indicated that dust was present below the clearance criteria of 0.5 mg/cm^. This value is lower than the clearance criteria set by NADCA.

Lemongrass Grill - This unit is 3,500 square feet in area with two floors. All exterior windows facing the WTC were blown inward depositing significant amounts of dust on all surfaces of the first floor. Minimal dust was present in the basement. The first floor is at street level with entrances from both Liberty and Cedar Streets. The lower level (basement) was used for food preparation and storage. Gypsum ceilings and hardwood floors are present throughout the dining area. Wood floor joists and sub-floor from the first floor constitute the basement ceiling. The dining area is decorated with Thai accents consisting of bamboo and thatch.

Grills, ovens, refrigerators, tables, chairs and a bar are on the first floor. The basement contains a walk-in refrigerator, freezers, preparation table, dishwasher, and dry goods storage. The floor of the basement is concrete. The establishment’s HVAC system is suspended from the ceiling of the first floor.

Prior to cleaning, all tables, chairs, containerized food and accent decorations were disposed. Restaurant equipment including woks, utensils, pots, pans, and flatware were vacuumed and washed.

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. Test 4D consisted of professional cleaning of the HVAC system using standard industry techniques. All horizontal surfaces were wet wiped. This cleaning method was used for each cleaning event. The HVAC system was also cleaned and tested.

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

Asbestos HVAC Cleaning Results - 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 12,000 vs. 3,000). The bulk sample was analyzed by PLM and found to be less than one percent asbestos. 92

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