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

2. Perform air sampling in the affected area to confirm the effectiveness of the decontamination procedures. If fiber concentrations are still elevated, repeat the decontamination procedures.

C. If the high reading was the result of other causes, initiate corrective action as determined by Ambient Group, Inc.

1.05 SAMPLING AND ANALYTICAL METHODS:

A. The following methods will be used by the Owner in sampling and analyzing samples used to collect air or wipe samples to determine the levels of airborne or surface contaminants.

1. Wipe samples shall be collected in accordance with ASTM El 728-02 and analyzed for metals, specifically Cadmium, Chromium, Copper, Lead, Nickel, and Zinc, in accordance with the NIOSH 7300M method, using Inductively Coupled Argon Plasma atomic emission spectroscopy (ICP).

2. Wipe samples shall be collected in accordance with ASTM D6661-01 and analyzed for Dioxins/Furans in accordance with the EPA SW-846-8290 method, using High Resolution GC/MS.

3. Air samples for asbestos structures shall be collected and analyzed in accordance with the method outlined in EPA 40 CFR Part 763, using Transmission Electron Microscopy (TEM).

1.06 SCHEDULE OF SAMPLES:

A. Frequency and duration of the air sampling during removal of dust and debris shall be representative of the actual conditions during the Work. The size of the project area will be a factor in the number of samples required to monitor the abatement activities. The following minimum schedule of airborne fiber samples, as determined by PCM, shall be required daily during the work shift. Area sampling shall be performed at the following locations:

1. Two area samples outside the project work area in uncontaminated areas of the building, remote from the decontamination fecilities.

a. Primary location selection shall be within 10 feet of isolation barriers

b. Where negative ventilation exhaust ducting runs through uncontaminated building areas, one of the area samples will be required in these areas to monitor any potential contaminant migration.

c. Where adjacent non-work areas do not exist, a sample shall be taken elsewhere in the building.

-2:— “One area sample within the uncontaminated entrance to each worker decontamination and waste decontamination enclosure system.

B. Post-abatement clearance air sampling shall include the following number of samples:

1. A minimum of five (5) air samples, plus one additional sample for every 5,000 square 23 © AMBIENT GROUP, INC. - 2002 AIR AND WIPE SAMPLING

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