Forwarding WTC air monitoring scope for final review, Aug 2002

NYC 9/11 Public Portal Document

Environmental Protection Agency Pt. 763, Subpt. E, App. A Shrink fit gel-bands may be used for this d. Check the sampling system for leaks purpose and are available from filter manu­ with the end cap still in place and the pump facturers and their authorized distributors. operating before initiating sample collec­ J. Use wrinkle-free loaded cassettes in the tion. Trace and stop the source of any flow sampling operation. indicated by the flowmeter under these con­ 5. Pump setup. ditions, a. Calibrate the sampling pump over the e. Select an appropriate flow rate equal to range of flow rates and loads anticipated for or greater than 1 L/mln or less than 10 L/min the monitoring period with this flow meas­ for 25 mm cassettes. Larger filters may be uring device in series. Perform this calibra­ operated at proportionally higher flow rates. tion using guidance from EPA Method 2A f. Orient the cassette downward at approxi­ each time the unit is sent to the field (See mately 45 degrees from the horizontal. Reference 6 of Unit III.L.). b. Configure the sampling system to pre­ g. Maintain a log of all pertinent sampling clude pump vibrations from being trans­ information, such as pump identification mitted to the cassette by using a sampling number, calibration data, sample location. stand separate from the pump station and date, sample identification number, flow making connections with flexible tubing. rates at the beginning, middle, and end, start c. Maintain continuous smooth flow condi­ and stop times, and other useful Information tions by damping out any pump action fluc­ or comments. Use of a sampling log form is tuations if necessary. recommended. See the following Figure 2:

683

NYC-WTC_000139298