Revised scopes of work for indoor dust cleaning program, August

NYC 9/11 Public Portal Document

ii. Residents shall not be present in their residence during aggressive air sampling activities. iii. Personal protective equipment including disposable clothing, gloves, and respirators shall be worn during aggressive air sampling activities. iv. HVAC systems shall be shut down or isolated locally during aggressive air sampling. V. Room and window air conditioners shall not be operated during aggressive 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 ofeach 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 ofsampling. 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 fi-om obstructions. The sampling cassettemust be placed on atripod, not taped to existing surface and should be directed downward at a 45 degree angle. d. Common spaces will be sampled without the use offorced air devices (fans, leafblowers 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 ofair 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 ofnecessary documentation shall be hand delivered daily to EMSL Laboratories at: 307 W. 38*St.,New York,NewYork 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 13 residences, as instructed by EPA. This sampling will consist ofthe collection of3 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

8

NYC-WTC_000139143