1. Monitoring Station Location and Siting Initially on a residential porch at Marina Towers, aligned with the Mirant Potomac River Generating Station (PRGS) Moved to roof on request of resident (noise and compressed gases were of concern) Secure location with temperature and humidity control, as required for TE-43C SO 2 analyzer took time to acquire Also required power supply installation See following slide for orientation of Marina Towers and operating area

2. Proximity of Marina Towers to Potomac River Generating Station

3. ENSR/Mirant Meteorological Station

4. Location of Meteorological Station Relative to Marina Towers

5. Program Constraints No meteorological data available to the study team Meteorological system proposed for logging on Met One E-BAM PM-2.5 system, and subsequent production of time-resolved presentations E-BAM PM-10 is USEPA FRM, E-BAM PM-2.5 is not

6. Duration of Study Start Date – 26 OCT 2006 (PM-2.5 only) Add SO 2 – 16 APR 2007 –Some SO 2 data lost due to elevated temperatures in the sampler housing area –Some PM-2.5 data lost due to sampler malfunction towards end of study End Date – 16 OCT 2007 Demobilization – 16 OCT 2007

7. QA/QC and Operations Routine calibrations as required All calibrations performed and documented in accordance with 40CFR58 All gases and standards NIST traceable and documented “Shelter” temperatures exceeded 30°C on occasion, acceptable for E-BAM, not for TE-43C (SO 2 )

8. E-BAM Uses beta attenuation for measurement of mass Uses continuous filter tape for mass measurement Lightweight and completely portable –A/C, battery or solar-panel operation possible –Important because first site location was on tenant’s balcony thus small size and portability important USEPA FRM for PM-10, CA equivalent for PM-2.5 Continuous measurements –Accuracy and precision consistent with USEPA requirements for Class III designation for PM 2.5 Accuracy of 2.5 μg in 24 hour period –Data are updated every second, and data records updated every minute Data retrieval via satellite, dial-up, cell-phone radio modems available or direct connection to built in data logger

9. TEOM Uses tapered element oscillating microbalance, for mass measurements Uses discreet filters for mass collection Larger size, less portable –Requires additional housing for outdoor use –250 lb weight including required outdoor enclosure USEPA equivalent PM-10 monitor, USEPA CACM for PM-2.5 Real-time mass concentration averages: 10 min default, 10 to 3600 sec; long-term averaging: 30 min, 1, 8, and 24 hr, with a data output rate of 2 sec Precision: ±1.5 μg/m³ (1-hour ave), ±0.5 μg/m³ (24-hour ave)

10. Federal Reference Methods Three classes of equivalent method are established –Class I equivalent methods provide capability for collection of several sequential samples automatically without intermediate operator service. Samples on daily basis. –Class II equivalent methods include all other filter based methods that produce a 24-hour measurement. –Class III equivalent methods include both continuous or semi- continuous methods. The FRM PM2.5 Air Sampler is an advanced manual method for performing PM2.5 measurements. The sampler was designed to meet the monitoring requirements of the EPA reference method for monitoring PM2.5 –Advantages: The FRM PM2.5 Air Sampler provides a direct measure of PM mass. It is not sensitive to particle size, density, or color and is highly reliable in ambient conditions ranging from –45 to +45°C, as well as in areas with high humidity conditions. –Disadvantages: The FRM PM2.5 Air Sampler is a manual method that cannot provide continuous, real-time data. It is time consuming, laborious, and costly.