Chain of custody form for DEP environmental samples, 2001

NYC 9/11 Public Portal Document

design is open throughout the unit, with a half bath, utility closet, and coat closet located in the south end of the room. The A/C system air handler is suspended under the third floor deck, above the suspended acoustical tiled ceiling. The system has two closed return air grills, a blower cabinet, and a supply trunk with a four way directional supply grill. The system's condenser/compressor unit is located in the building's atrium roof area at the second floor elevation.

The procedures used to clean the Chiropractor’s Office and Mattress Store were identical. They mirrored the procedures used by HVAC cleaning companies when responding to ordinary HVAC cleaning requisitions. The following cleaning activities were conducted, in the following order:

1. A clean plastic barrier was installed on the floor surface, three feet to either side of the suspended HVAC system, from the return intake to the furthest supply grill. 2. Access points were selected at the return and supply sides of the duct system. A HEPA- filtered vacuum collection system was installed at the end of the supply run to collect internal dust. 3. A rotating brush system was used to dislodge dust in the direction of the vacuum collection system. 4. Degreasing agents were used on the HVAC internal coil units and cleaned. Supply grills were cleaned in a similar fashion. 5. A biocide agent was applied to the duct's internal components and allowed to dry. 6. An encapsulant was applied to the internal surfaces in order to ensure that residual dust was sealed in. 7. The work area was cleaned of all equipment and plastic protection. 8. The system was visually inspected at the air handling unit access panels for view of internal components. The duct work was visually inspected for dust in the return and in the supply lines.

Carpet Cleaning (study) Two methods were utilized to clean the carpets in the Chiropractor's Office and the Mattress Store: 1) Nilfisk™ vacuum with HEPA filtration, and 2) wet vacuuming. Carpets were wet- vacuumed in the Chiropractor's Office and in the Mattress Store, using standard carpet shampooing equipment available to the public at rental stores. The carpets were cleaned twice, sampled, and disposed as porous material. Initially, the carpets were cleaned running in the direction of the room fi-om front to back (Liberty Street to Cedar Street). The carpets were then cleaned again, in a direction crossing the room from side to side.

Warm water only was used in the Chiropractor's Office. Soap (carpet shampoo) and warm water were used in the Mattress Store. Seven-in-One™ brand professional carpet shampoo, manufactured by Kent Investment Corporation, was diluted at two ounces per gallon of water. This dilution achieved 1,400-2,000 square feet of cleaning coverage.

Common Areas (study) The common areas were the first areas of the building cleaned, in order to provide a dust-free area for Level D entry through the common spaces, and to provide a safe location for equipment storage. All foyers, stairways, and halls were vacuumed using commercial quality HEPA vacuums. All horizontal and vertical surfaces in the common areas were wet wiped where 20

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