Updated WTC cleanup and monitoring SOWs, July 2002

NYC 9/11 Public Portal Document

i. Before beginning aggressive air sampling, forced air equipment (such as a 1 horsepower electric leaf blower) shall be 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. ii. For modified aggressive air sampling forced air equipment shall not be employed. ..A- iii. All other procedures are identical for aggressive and modified aggressive air sampling b. One 20-inch Ian shall be installed per 10,000 cuhie feet of rootn Space and run at low speed. The fen shall operate continuously th^^^out saug^^^^^^^jl not be turned off until sampling is completed. c. For studio apartments 3 samples shall be Elected. For 1-bedroom ap :ito3efits and J- above 5 samples shall be collected. Sampling equiphient shall be placed it I*bving areas and away from obstructions. The sampling casscttc must be placed on a tripod and not taped to existing surfaces. d. Common spaces will be sampled withi Reused ced air devices (fans, leaf blowers etc). For small spaces, less t^ 50 square f 3 samples will be collected. For large spaces greater than 1 and h ^ban 25,000 square feet 5 samples will be collected. Fo^^ 25,000 square feet, 1 sample will be collected for each 5,000 square feet MOBSI equipment shall be placed away fi-om obstructions. The .slhipling .^Isette be placed on a tripod directed downward at a 45 deg| pngle agd'not tapc^o existing surfaces. e. Air samples shall be^ cted in accordance with the procedures specified in NIOSH 7400 Method for PCX and 7402 for TEM. Air sampling cassettes need to be monitored to ensure pumps iate net clogging by monitoring flow rates. The minimum llll^mple vohSPte required is 3* f. Wipe samples will be collected at io percent of the residences where sampling only has been requested, up to a maximum of 50 units, as instructed by EPA. This WBpfiiiigsWill consist of the collection of one wipe sample each for dioxin, total mercury {a separate wipe sample is required for each parameter). samples will be collected in accordance with procedui r specified in HUD Appendix 13.1. Dioxin wipe samples will be jF collected I accordance with the procedures specified in ASTMD 6661-01. The cont :tof shall document all the necessary information regarding sampling g- II activities^ fill out all field logs, data sheets, and chain-of-custody forms. The contr^pr shall use F2L for all sample and chain-of-custody documentation. Samples must be labeled and accompanied with completed chain-of-custody forms before I shipping to the designated laboratory. The label must include the EPA Project Tracking Number. Samples will be packed, sealed and shipped to EPA Contract Laboratory for analysis. h. All information must be maintained using the secure EPA website (url, user name and password to be provided by EPA). Dates for monitoring and/or cleaning shall be provided to EPA electronically in an EPA approved format within 24 hours. Information on sampling activities (date, sample ID) shall be provided to EPA, via the

NYC-WTC_000139551