2002 E-Mail Sent M. Gilsenan

NYC 9/11 Public Portal Document

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ofthe collection of3 pre clean-up and 3 post clean-up wipe samples for total metals and mercury (Note: a separate wipe sample is require for analysis for mercury). All wipe samples will be collected in accordance with procedures specified in HUD Appendix 13.1.

b. Samples must be labeled and accompanied with completed chain ofcustody forms before shipping to the designated laboratory. The label must include the EPA Project Tracking Number. Samples will be packed, sealed and shipped to USEPA Contract Laboratory for analysis. Metals samples will be analyzed using EPA Method SW-846 601 OB. Mercury samples will be analyzed using EPA Method SW-846 7471.

17. Post Clean-up Air Sampling Procedures a. Sampling shall not begin until a visual inspection confirms the absence ofvisible dust and debris. Post cleaning air sampling shall be completed within 24-hours ofthe completion of cleaning activities. b. All surfaces must be completely diy prior to the start of sampling. c. Window air conditioning units where applicable shall be run/operated at least 15 minutes prior to the start of sampling. The air conditioning units shall operate continuously throughout the sampling. d. Based on consultation with resident, aggressive or modified aggressive air sampling will be conducted upon completion ofcleaning. Before the start ofsampling, forced air equipment (such as a 1 horsepower electric leafblower) maybe used to direct exhaust air against walls, ceilings, floors and other surfaces. When directing the exhaust, caution shall be taken to minimize disturbance and potential damage to furnishings and personal belongings. e. One 20-inch fan shall be installed per 10,000 cubic feet of room space and run at low speed. The fan shall operate continuously throughout sampling and shall not be turned off until sampling is completed. f. For studio apartments 3 samples shall be collected. For 1-bedroom apartments and above 5 samples shall be collected. Sampling equipment shall be placed in living areas and away fi-om obstructions. The sampling cassette must be placed on a tripod and not taped to existing surfaces. g- Common spaces will be sampled without the use offorced air devices (fans, leafblowers etc). For small spaces, less than 260 linear feet and 160 square feet, 3 samples will be collected. For large spaces greater than 260 linear feet or 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 fi'om obstructions. The sampling cassette must be placed on a tripod and not taped to existing surfaces. h. Asbestos air samples shall be collected in accordance with the procedures specified in NIOSH Method 7400. Air sampling pumps will be operated at 10 liters per minute for eight (8) hours to achieve the maximum volume requirement of4800 liters.

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