Document header page for 20 Vesey Street records, Jan 2002

NYC 9/11 Public Portal Document

JAN-28-2002 22:21 MERRILL LYNCH 212 236 2301 P.05/06

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

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

procedures listed below were Phase 11 Final Cl anu Procedure Overview - After the completed the floor may be reoccupied with no restrictions. workers under the direction of A final, detailed fine cleaning was performcd by certified asbestos furniture and personal items were a specialized disaster recovery fum. The space walls, floors, remove contaminates. fined cleaned to remove residual dust. All rugs are shampooed to

Asbestos Final-clearance air sample collection and analysis (1) Asbestos air sample collection and analysis Transmission Electron a, PCM, Phase Contrast Microscopy and TEM, Microscopy samples were collected by GPS, a Licensed asbestos consulting firm. and less b. All post samples were required to be below 0.01 f/cc (PCM) than 70 Structures/mm2 for (TEM). If one sample was at or above these limits then the 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 the were TEM qualitative analytical technique. To be acceptable all results required to be reported as absent or negative for asbestos present.

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

Pg 3 of 4 Prepared by GPS Environmental Consultants. Inc

NYC-WTC 000112088