NYC-WTC_000209480

NYC 9/11 Public Portal Document

conducted. Residents shall not be present in their residence during aggressive air sampling activities. i. Before beginning aggressive air sampling, a 1 horsepower electric leafblower shall be used to direct exhaust aii against walls, ceilings, floors and other surfaces. This shall continue for at least five minutes per 1,000 square feet of floor. When directing the exhaust, caution shall be taken to minimize disturbance and potential damage to furnishings and personal belongings. ii. HVAC systems shall be shut down or isolated locally during aggressive air sampling. iii. Room and window air conditioners shall not be operated during aggressive air sampling. iv. Leaf blowers shall not be employed for modified aggressive air sampling. V. 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 ofroom 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 saimpling. The fans shall operate continuously throughout sampling and shall not be turned off until sampling is comjjleted. c. For studio apartments 3 air samples shall be collected. Fori -bedroom apartments and above, 5 air samples shall be col lectc'd. Sampling equipment shall be placed in living areas and a.way 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, leafbiowers 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 encl e. Air samples will be collected in accordance with the procedures specified in NIOSH 7400 Method for PGM and 7402 for TEM. 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. All clearance 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 ofthe residences where sampling only has been requested, up to a maximum of 50 residences, as instructed by EP A. This sampling will consist ofthe collection of 3 wipe samples each for dioxin, total metals and mercury (Note: a separate wipe sample is required for eachparameter at each location). Metals and mercury wipe samples will be collected in accordance with procedures specified in

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CITY_21MC100_000439011 NYC-WTC_000209486