Scope of Work: Air sampling procedures for WTC dust cleaning,

NYC 9/11 Public Portal Document

The Project Monitor shall submit upon request to the EPA copies of the log book as requested via fax or alternative format agreed upon and within two days of request. Final air sampling shall be performed with 24 hours of final visual inspection.

18. Post Clean-up Air Sampling Procedures 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 Within 24 hours of whO. 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 foe start of sampling., c. Window air conditioning units where applicable shall be Tun/opefated at leasfIB minutes prior to the start of sampling. Qe air c^moning units .shall operate continuously throughout the sampling. Why is the air conditioning unit oper^m after clean Up when it wasn t operated dunng sampling prior to clean up? It should be Operated dunng sampling prior to clean up as well.. d. FJpoiteofflplehottofAe-elemmgreithe^aggfe^ >di fted aggressive -air sampling preeedufcs-wi'H-be-eondueted-te-veri-fy'-att^M Ort- elcan-up eriteria. Aggressive er modifred aggressive air sampling wtll -be ■used for Scope A- clean-ups, based on consultation with-resident; In aggressive air monitoring sampling situations-, before the start ofsampling; a 1 horsepower electric leaf blowci:|yill be used to direct exhaust air against walls, ceilings, floors and-othcr surfaces.-When- direeting the exhaust-; eaution-shaH-be-tAcn- to-n^Knizc di^&ani v ami p< -ential-damagc to fitmishings and personal-belengittgs: The proeedure-wseribedylow for modified-aggicssive-sampling teehttiqtteswvm-also^ e. In modified aggre; ve sampling, one 2'(i- nKh fan shall be installed per 10,000 cubic ^Teet of room space H run at low speed. ^e fan shall operate continuously throughout ■ npling aniFshall ipt be turned off unitil sampling is completed. When should this fanbe tumedon^f f. For studio aparfAer s ? air lamples shall be collected. For 1-bedroom apartments and above 5 air sample: |feollected. Sampling equipment shall be placed in living areas anil away from' ictions. The sampling cassette must be placed on a tripod Ihd not timed h ) existing surfaces. Gommon spaet «-wi+l be sampled without the use of forced air devices (fans; leaf blowerse1e>. For small spaces, less than 160 square feet, 3 air samples will be collected. J •r large spaces greater than 160 square feet and less than 25,000 square feet 5 air sa iples will be collected. For spaces greater than 25,000 square feet, 1 air sample ^11 be collected for each 5,000 square feet. Sampling equipment shall be away from obstructions. The sampling cassette must be placed on a tripod fed downward at a 45 degree angle and not taped to existing surfaces. Air samples shall be collected in accordance with the procedures specified in NIOSH 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 sampling volume required is 3600 liters. i. 24-hour tum-around-time shall be specified for the analysis of all post-cleaning air samples for Scope B cleanups.

NYC-WTC_000140367