EPA work plan review, 133-135 and 21-23 buildings, August 2005

NYC 9/11 Public Portal Document

Part II - Environmental Community Monitoring Plan 133-135 Greenwich & 21-23 Thames Streets Airtek Project 05-0701— Rev 1 August 11, 2005

o masses and balances NIST-traceable o temperature and pressure NIST-traceable • Calibrations: The sample collection staff performs a multi-point flow calibration of each particulate sampler using an orifice unit (quarterly, after maintenance or repairs and when indicated). • Precision checks through collocation: A second sampler is placed the monitoring station. • Performance audits: o Quarterly audits: An IH Quality Coordinator does a one-point flow audit quarterly on all samplers, using a different orifice unit than the one used to calibrate the sampler. • Data audit: Data Manager reviews all the data for anomalies.

3.4 Quality Assurance for PM 5 These are measures to ensure the quality of data gathered using manual samplers of PM2.5. (Speciated PM2.5 sampling is done under a different set of procedures.) A manual PM2.5 monitoring system consists of a sampling system at the site, an analysis system at a central location and a transportation system to get the sample filters from one to the other. The sampling system consists of a sampler (one or more at each site) with attached temperature and pressure instruments and a human operator who loads new (unexposed) filters into the sampler, programs it to sample each filter for 24 hours (normally midnight to midnight) on a specified day, and retrieves the exposed filters afterward. "Sequential" samplers may be used, capable of automatically changing filters to sample for several days in a row. Sequential samplers can run continuously, except for maintenance and QA checks. The gravimetric analysis system consists of a microbalance in a climate-controlled weighing room and a human analyst trained to operate it. The weighing must take place within a narrow range of temperature and humidity. Before being weighed, both unexposed and exposed filters must be conditioned for at least 24 hours in this environment. The exposed sample filters are transported in a cooler to limit the loss of volatile material, and are then kept in a refrigerator if they are cannot be weighed within 10 days of sampling (they still must be weighed within 30 days of sampling to be valid). Unexposed filters are taken out to the site under similar controlled conditions (usually in a cooler, although this is not necessary). • Data requirements:

o 75% data recovery. o Data quality objective: 10% coefficient of variation. The coefficient of variation, CV, is the standard deviation as a fraction of the mean: .. cy-

• Measures of Accuracy and Bias:

NYC-WTC 000134970