Updated WTC cleanup and monitoring SOWs, July 2002

NYC 9/11 Public Portal Document

a. Sampling shall not begin until a visual inspection confirms the absence of visible dust and debris. Post cleaning air sampling shall be performed upon successful visual inspection and completed within 24 hours. A successful visual inspection shall be an inspection that verifies the absence of dust and debris. b. All surfaces must be completely dry 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. Upon completion of the cleaning, either aggressive or modified aggressive air sampling procedures will be conducted to verify attainment of the clean-up criteria. Aggressive or modified aggressive air sampling will toe mined for Scope A clean-ups, based on consultation with resident. In aggressive air monitoring sampling situations, before the start of sampling, a 1 horsepower electric leafblower will be used to direct exhaust air against walls, ceilings, floors and othersurfaces. When directing the exhaust, caution shall be taken to minimize disturbance and potential damage to furnishings and personal belong rigs. The procedure described below for modified aggressive sampling techniques i [1 also be employed e. In modified aggressive sampling, one 20-inc [fan shall be Instiled per 10,000 cubic feet of room space and run at low spi ||:,shall operate continuously throughout sampling and shall not be turned offuntil! is completed. f. For studio apartments 3 shall ji Cted. For 1-bedroom apartments and above 5 samples shall be c^flcted. Sampling qipment shall be placed in living areas and away from obstructions. The sampling cattle must be placed on a tripod and not taped to existing surfaces. g- Common spaces will be sampled withoi|^e use of forced air devices (fans, leaf jblowers 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 wiSbe 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 The WB^BWassette J- -v must be placed r on a tripod r directed downward at a 45 degree angle and^^hp| taped to existing surfaces. h. Air samples shall be collected in accordance with the procedures specified in NIOSH 7400 Method for Ur PCM and 7402 for TEM. Air sampling cassettes need to be monitored to ensu ■e pumps are not clogging by monitoring flow rates. The minimum sampling volume required is 3600 liters. 1. 24-hour turn-around-time shall be specified for the analysis of all post-cleaning air samples for Scope B cleanups. j. 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 for analysis to EMSL laboratories at: 307 W. 38* St., New York, New York 212-290-0051. k. All information must be maintained using the secure EPA website (url, user name and

NYC-WTC_000139556