Preliminary scope of work document for cleaning 114 Liberty Street,

NYC 9/11 Public Portal Document

December 17, 2002 114 LIBERTY STREET REMOVAL OF DUST, DEBRIS, AND CONTAMINATED MATERIALS

B. Remove the second layer of plastic surface barriers, leaving only the critical bam'ers in place, and dispose of as asbestos contaminated waste material.

C. Wait 4 hours or more to allow HEPA-filtered exhaust units to clean air of airborne asbestos fibers.

3.03 FINAL CLEANING:

A. Carry out a final cleaning of ail surfaces in the Work Area in the same manner as the previous cleaning. This cleaning is now being applied to existing room surfaces and critical barriers.

B. The Contractor shall request that a final clean up inspection be performed to insure that all visible dust has been removed, that the area is free of contaminated dust, waste bags, and/or debris. Ambient Group and the Contractor shall perform a complete visual inspection of the entire work area.

C When the area is visually determined to be clean, and following a 1 hour waiting period, clearance sampling shall be performed.

3.04 FINAL AIR AND WIPE SAMPLING:

A. After the Work Area is found to be visually clean, air and wipe sampling will be conducted in accordance with Section 05 - Air and Wipe Sampling.

B. In the event that release criteria is not met, all costs associated with re-testing and re-cleaning shall be borne by the Contractor.

C. All clearance sampling and analysis shall be performed by Ambient Group.

3.05 REMOVAL OF WORK AREA ISOLATION:

A. Following clearance, dismantling of the decontamination unit and/or critical barriers is to be conducted in a controlled feshion. The following controls are to be utilized:

1. Dismantling is to be coordinated wth the Owner.

2. The Contractor is to conduct this work with personnel protective equipment.

3. The Contractor is to utilize HEPA-vacuuming/wet-wiping techniques to clean up any miscellaneous debris encountered or dislodged during this activity.

4. The Owner's testing laboratory may conduct air sampling to monitor this work.

3.06 SUBSTANTIAL COMPLETION OF ABATEMENT WORK:

A. Abatement Work is Substantially Complete upon meeting the requirements of this section. including submission of:

1. Certificate of Visual Inspection.

2. Air and Wipe clearance sampling results

54 © AMBIENT GROUP, INC. -2002

PROJECT DECONTAMINATION

NYC-WTC_000155582