1. Clark County PM 10 Saturation Study Robert A. Baxter, CCM T&B Systems Clark County Air Quality Forum – 03/14/06

2. Overview Objectives of the Study Selection of PM 10 Measurement Methods Saturation Sampling Network Quality Assurance of Measurements Saturation Study Observations Overall Results and Recommendations

3. Objectives State Implementation Plan committed to a PM 10 saturation study Assess the representativeness of the current monitoring network Determine the inter-basin and intra-basin transport during high wind speed events Determine the neighborhood impacts of major sources in the region

4. Measurement Methods Evaluation Criteria –Continuous Method –Acceptable performance –No environmental controls –Solar power –Inconspicuous –Cost-effective –Reliable Two evaluation sites –Crustal PM 10 –Combustion emissions related PM 10 Evaluated Instruments Met One E-Sampler R&P Dustscan TSI DustTrak

5. Sampler Evaluation October/November 2004 Joe Neal Non-urban

6. City Center Urbanized Sampler Evaluation October/November 2004

7. Sampler Evaluation Selected Instrumentation TSI DustTrak External data logging Extended sample inlet Solar/available power

8. DAQEM Sampling Network

11. Combined Sampling Network

12. Quality Assurance Three scheduled audits –Evaluation study –Saturation study –Data processing and validation Routine quality control checks –DustTrak flow and zero –Power system checks –Download and review of data Quality Control site – Joe Neal

13. Saturation Study Observations Historical observations Observed climatology and meteorology Saturation network versus DAQEM network comparisons High wind speed events

14. Historical Observations

15. 94311421 # of Exceedances

16. Historical Observations Effect of wind speed on exceedance values 2000 – 2003 data

17. Study Observations 24-hour average DAQEM network PM 10 May 9 May 16 May 29 June 17 Fires

18. Study Observations 24-hour average saturation network PM 10 May 9 May 16 May 29 June 17 Fires

19. High Wind Speed Events 24-hour average wind speed May 9 May 16 May 29 June 17 Fires

20. High Wind Speed Events Hourly saturation network PM 10 values

21. High Wind Speed Events Hourly saturation network PM 10 values

22. Study Results Adequacy of DAQEM Network 24-hour average PM 10 levels relatively low High wind speed events could have produced exceedances in prior dry years DAQEM network reflected observed patterns in the historical analysis Saturation network saw similar patterns but added higher values in the south Concentration distributions for “high-PM days” were evaluated

23. Network Observations May 29, 2005 Saturation DAQEM

24. Network Observations June 17, 2005 Saturation DAQEM

25. Study Results Transport During High Wind Events Four high wind speed events High wind speed events could have produced exceedances in prior dry years June 17 event reflected southwest to northeast axis with apparent transport

26. Composite June 17, 2005 Saturation and DAQEM Networks

27. Study Results Neighborhood Impacts Two sites adjacent to major sources –West side near quarry – Mountain Crest –Northeast side near quarry – Speedway Influence of the sources could be seen at the adjacent sites in stable conditions (10-20 ug/m 3 ) Source contribution in high wind speeds will be related to the source mitigation efforts

28. Study Average PM 10 by Hour Mountain Crest Wetlands Blue Diamond

29. Summary Additional site in the south for inflow and observations during high wind speed events Review the status of the west side sites ~15 mph wind speeds needed for entrainment Material handling added 10 to 20 ug/m 3 to regions adjacent to quarry sites Optical method worked well but with some limitations Observed PM 10 higher values were short lived due to limited PM reservoir Field observations of dust mitigation appeared very effective in reducing visible emissions

30. Questions? Please contact: Department of Air Quality and Environmental Management (DAQEM) (702) 455-5942