Asbestos cleanup procedures and air sampling report, GPS Environmental Consultants,

NYC 9/11 Public Portal Document

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was re-cleaned until all sample results were below these limits, Isolation barriers were removed only after passing this post sampling I criteria.

Westside cleanup and other areas containing dust (1) 1" cleaning - all surfaces were HEPA vacuumed and wet wiped by asbestos certified handlers and supervisors. (2) All areas were inspected by GPS personnel and rc-cleaned as necessary. (3) Asbestos air sample collection and analysis a, PCM, Phase Contrast Microscopy and TEM, (Transmission Electron Microscopy) samples were collected by GPS, a Licensed asbestos consulting firm. b. All post samples were required to be below 0.01 f/cc (PCM) and less than 70 Structurcs/mm2 for (TEM). If one sample was at or above these limits then the area was rc-cleancd until all sample results were below these limits.

Phase 11 Final Cleanup Procedure Overview • After the procedures listed below were completed the floor may be reoccupied with no restrictions.

A final, detailed fine cleaning was performed by certified asbestos workers under the direction of a specialized disaster recovery firm. The space walls, floors, furniture and personal items were fined cleaned to remove residual dust. All rugs are shampooed to remove contaminates. Asbestos Final-clearance air sample collection and analysis (1) Asbestos air sample collection and analysis a, PCM, Phase Contrast Microscopy and TEM, Transmission Electron Microscopy samples were collected by GPS, a Licensed asbestos consulting firm. b. AU post samples were required to be below 0.01 f/cc (PCM) and less than 70 Structures/mm2 for (TEM). If one sample was at or above these limits then tlic area was re-cleaned until all sample results were below these limits. (2) Asbestos wipe sampling was collected from surfaces in representative locations and analyzed for the presence or absence of asbestos using tlie TEM qualitative analytical technique. To be acceptable all results were required to be reported as absent or negative for asbestos present.

Phase III Procedure - The ventilation ductwork was inspected by a trained HVAC specialist. Areas determined to be contaminated were cleaned by a certified duct cleaning firm. All fresh air and compartmental filters were replaced. Both the upper and lower fresh air fans were turned on after filter replacement, cleaning and inspections were complete. As a measure to i ensure a safe environment for all occupants, GPS conducted asbestos air sampling for each floor for a 24-48 hour period.

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