Scope of Work draft for World Trade Center dust cleaning,

NYC 9/11 Public Portal Document

air sampling. vi. Leaf blowers shall not be employed for modified aggressive air sampling. vii. All other procedures are identical for aggressive and modified aggressive air sampling, unless otherwise noted. b. At least one 20-inch fan shall be placed in the center of each room sampled. One fan per 10,000 cubic feet of room space shall be used. The fans shall be operated on slow speed and pointed toward the ceiling. The fans shall run for at least 15 minutes prior to the start of sampling. The fans shall operate continuously throughout sampling and shall not be turned off until sampling is completed. c. For studio apartments 3 air samples shall be collected. For 1-bedroom apartments and above, 5 air samples shall be collected. Sampling equipment shall be placed in living areas and away from obstructions. The sampling cassette must be placed on a tripod, not taped to existing surface and should be directed downward at a 45 degree angle. d. Common spaces will be sampled without the use of forced air devices (fans, leaf blowers etc). For small spaces, less than 160 square feet, 3 samples will be collected. For large spaces greater than 160 square feet and less than 25,000 square feet 5 samples will be collected. For spaces greater than 25,000 square feet, 1 sample will be collected for each 5,000 square feet. Sampling equipment shall be placed away from obstructions. The sampling cassette must be placed on a tripod, not taped to existing surfaces and directed downward at a 45 degree angle. e. Air samples will be collected in accordance with the procedures specified in NIOSH 7400 Method and analyzed by phased contrast microscopy (PCM) followed by Asbestos Hazard Emergency Response Act (AHERA) transmission electron microscopy (TEM). The flow rate for collection of air samples shall be at least 10 liters per minute and no more than 15 liters per minute. Air sampling cassettes need to be monitored to ensure that cassettes are not clogging by monitoring flow rates. The minimum sample volume required is 3600 liters. These air samples and copies of necessary documentation shall be hand delivered daily to EMSL Laboratories at: 307 W. 38*^ St, New York, New York 212-290-0051. f. Wipe samples will be collected at 10 percent of the residences where sampling only has been requested, up to a maximum of 13 residences, as instructed by EPA. This sampling will consist of the collection of 3 wipe samples each for dioxin, total metals and mercury (Note: a separate wipe sample is required for each parameter at each location). Metals and mercury wipe samples will be collected in accordance with procedures specified in HUD Appendix 13.1. Dioxin wipe samples will be collected in accordance with the procedures specified in ASTMD 6661-01. Wipe samples and copies of necessary documentation will be packed, sealed and shipped daily by courier for next day delivery to Paradigm Analytical Laboratories at: 2627 Northchase Parkway SE, Wilmington NC 2840^ g- 24-hour tum-around time shall be specified for the analysis of all samples

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NYC-WTC_000140406