Forwarding WTC air monitoring scope for final review, Aug 2002

NYC 9/11 Public Portal Document

R. 763. Subpt. E, App. A 40 CFR Ch. I (7-1-00 Edition) 10. Calibrate sampling pumps and their 17. A minimum of 13 samples are to be col­ flow Indicators over the range of their in­ lected for each testing site consisting of the tended use with a recognized standard. As­ following: semble the sampling system with a rep­ a. A minimum of five samples per abate­ resentative filter (not the filter which will ment area. be used in sampling) before -and after the b. A minimum of five samples per ambient sampling operation. area positioned at locations representative 11. Record all calibration Information. of the air entering the abatement site. c. Two field blanks are to be taken by re­ 12. Ensure that the mechanical vibrations moving the cap for not more than 30 seconds from the pump will be minimized to prevent and replacing it at the time of sampling be­ transferral of vibration to the cassette. fore sampling is initiated at the following 13. Ensure that a continuous smooth flow places: of negative pressure is delivered by the pump 1. Near the entrance to each abatement by damping out any pump action fluctua­ area. tions if necessary. 11. At one of the ambient sites. (DO NOT 14. The final plastic barrier around the leave the field blanks open during the sam­ abatement area remains in place for the pling period.) sampling period. d. A sealed blank Is to be carried with each 15. After the area has passed a thorough sample set. This representative cassette is visual inspection, use aggressive sampling not to be opened in the field. conditions to dislodge any remaining dust. 18. Perform a leak check of the sampling (See suggested protocol in Unit III.B.T.d.) system at each Indoor and outdoor sampling 16. Select an appropriate flow rate equal to site by activating the pump with the closed or greater than 1 liter per minute (L/mln) or sampling cassette in line. Any flow indicates a leak which must be eliminated before initi­ less than 10 L/min for 25 mm cassettes. Larg­ ating the sampling operation. er filters may be operated at proportionally 19. The following Table I specifies volume higher flow rates. ranges to be used:

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