Updated WTC cleaning and monitoring scopes of work, July 2002

NYC 9/11 Public Portal Document

sampling will be conducted. Residents shall not be present in their apartment during aggressive air sampling activities. 1. Before beginning aggressive air sampling, forced air equipment (such as a 1 horsepower electric leafblower) 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. iii. All other procedures are identical for aggressive and modified aggressive air sampling. b. One 20-inch fan shall be installed per 10,000 Cubic feet ofroom space and run speed. The fan shall operate continuously throughout sampling and shall not be turned off until sampling is completed. ; f c. 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 cassettemust be placed on a tripod and not taped to existing surfeces. 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 than25,000 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 bn a tripod directed downward at a 45 degree angle and not taped to existing surfaces. e. Air samples shall be collected in accordance with the procedures specified inNIOSH 7400 Method for PCM and 7402 for TEM. Air sampling cassettes need to be monitored to ensure pumps are not clogging by monitoring flow rates. The minimum sample volume required is 3600 liters. f. Wipe samples will be collected at 10 percent ofthe residences where sampling only has been requested^ up to a maximum of50 units, as instructed by EPA. This sampling will consist of the collection of one wipe sample each for dioxin, total metals and mercury (a separate wipe sample is required for each parameter). Metalsand mercuiy 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. g- The contractor shall document all the necessary information regarding sampling activities, fill out all field logs, data sheets, and chain-of-custody forms. The contractor shall use F2L for all sample and chain-of-custody documentation. Samples must be labeled and accompanied with completed chain-of-custody forms before 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

NYC-WTC_000138686