Union memo regarding school reopening, Oct 2001

NYC 9/11 Public Portal Document

stains. Furniture and items found in the school (i.e., books, papers, supplies, fixtures, furniture, etc.) were damp-wiped and/or HEPA-vacuumed. Scaffolding was setup in the auditorium to clean the vents and ceilings. The SCA also power- washed the exterior of the building and cleaned the windows.

Heating. Ventilation, and Air-Conditioning (HVAC) Units & Individual Unit Ventilators (Univents) The building engineer shut down the HVAC system at the time of the evacuation and prior to the collapse of the two towers. This action minimized the amount of debris infiltrating into the units. The SCA inspected the HVAC units and wet- cleaned and HEPA-vacuumed the interiors of the air-handling units (outside air chamber, mixing chamber, fan coils) and accessible ductwork downstream. Each univent was damp-cleaned and HEPA-vacuumed internally and externally.

BOE DSF removed the air filters from the air-handling units and installed higher- efficiency pleated filters. BOE DSF also removed and replaced the air filters on each of the univents. All filters will be changed on a monthly basis.

Roof and Walkway BOE DSF EHS and the SCA inspected the roof areas, especially near the outside air intakes, found debris and cleaned accordingly. The West Walkway Bridge has been wet-cleaned and HEPA-vacuumed. A number of barrier dust mats have been installed on the walkway and will be cleaned as needed when the building reopens.

Post-Cleanup Air Monitoring After the cleanup the air was again sampled by two third-party air monitoring firms and analyzed by Transmission Electron Microscopy. In an effort to provide quality control and quality assurance the Union requested that BOE DSF and the SCA utilize two third-party air monitoring firms. The two firms were ATC Associates and Taylor Environmental. All of the following air monitoring results indicate the school meets local, state and federal asbestos regulatory criteria for re-occupancy. The sampling results are as follows:

On September 30th, ATC Associates took 27 air samples on the 6th through the 11th floors and on escalators running from the 5th through the 9th floors. There were no detectable asbestos structures in any of the 27 air samples.

On September 301h, 66 air samples were taken by Taylor Environmental Group on the 6th through the 11th floors and on escalators running from the 5" through the 9th floors. Asbestos structures (1 or 2 structures) were detected in 15 samples but were below the regulatory requirement of 70 structures per square millimeter.

NYC-WTC 000106413