SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT PLANNING, RULE DEVELOPMENT, AND AREA SOURCES ANALYSIS OF EXCEPTIONAL EVENTS CONTRIBUTING TO A HIGH PM10 CONCENTRATION AT THE PERRIS AIR MONITORING STATION IN THE SOUTH COAST AIR BASIN ON APRIL 12, 2007 Final Report July 18, 2009 Authors Kevin R. Durkee Senior Meteorologist Mark E. Bassett Air Quality Specialist Reviewed By: Michael Laybourn, Air Quality Specialist Tracy A. Goss, P.E., Program Supervisor, PM Strategies Joseph C. Cassmassi, Planning and Rules Manager Elaine Chang, Deputy Executive Officer TABLE OF CONTENTS TABLE OF CONTENTS ....................................................................................................................................................i List of Figures .................................................................................................................................................................... ii List of Tables ...................................................................................................................................................................... ii 1 INTRODUCTION .................................................................................................................................................... 1 1.1 Purpose ................................................................................................................................................................. 1 1.2 Organization of this Document ............................................................................................................................. 1 1.3 Exceptional Events Rule Background ................................................................................................................... 3 1.4 Geographic Setting................................................................................................................................................ 4 1.5 Regulatory Measures ............................................................................................................................................ 8 1.6 Historical Perspective of PM10 in the South Coast Air Basin .............................................................................. 9 2 HIGH WIND EXCEPTIONAL EVENT ANALYSIS: April 12, 2007 ............................................................. 13 2.1 Event Summary ................................................................................................................................................... 13 April 12, 2007 PM10 Exceptional Event - Perris Air Monitoring Station .............................................................. 13 Flagging of Data ....................................................................................................................................................... 14 Exceptional Event Criteria Summary ....................................................................................................................... 14 Affects Air Quality .............................................................................................................................................. 14 Is Not Reasonably Controllable or Preventable .................................................................................................. 15 Was a Natural Event ............................................................................................................................................ 16 Causal Connection .................................................................................................................................................... 17 Concentration was in Excess of Normal Historical Fluctuations ............................................................................. 18 The “But For” Test ................................................................................................................................................... 18 Reasonable Measures ............................................................................................................................................... 19 Public Notification ................................................................................................................................................... 19 Checklist of Exceptional Event Requirements ......................................................................................................... 20 2.2 Detailed Event Analysis ...................................................................................................................................... 21 PM Summary ............................................................................................................................................................ 21 Meteorological Setting ............................................................................................................................................. 31 Windblown Dust Analysis ....................................................................................................................................... 46 Conclusion ................................................................................................................................................................ 65 3 SUPPORTING MATERIALS ............................................................................................................................... 67 3.1 News Articles ....................................................................................................................................................... 67 3.2 National Weather Service Watches, Warning & Advisories ............................................................................... 76 NWS San Diego Forecast Office .............................................................................................................................. 76 3.3 National Weather Service Hazardous Weather Outlooks ................................................................................... 81 NWS San Diego Forecast Office .............................................................................................................................. 81 3.4 National Weather Service Forecast Discussions ................................................................................................ 85 NWS San Diego Forecast Office .............................................................................................................................. 85 NWS Los Angeles/Oxnard Forecast Office ............................................................................................................. 96 i 3.5 SCAQMD Windblown Dust Advisory ................................................................................................................ 112 3.6 National Climatic Data Center Weather Event Records ................................................................................... 113 3.7 U. S. Forest Service Web Cam .......................................................................................................................... 129 3.8 Additional Wind Data ....................................................................................................................................... 133 LIST OF FIGURES Figure 1-1 ............................................................................................................................................................................ 5 Figure 1-2 ............................................................................................................................................................................ 6 Figure 1-3 ............................................................................................................................................................................ 7 Figure 1-4 .......................................................................................................................................................................... 12 Figure 2-1 .......................................................................................................................................................................... 25 Figure 2-2 .......................................................................................................................................................................... 32 Figure 2-3 .......................................................................................................................................................................... 33 Figure 2-4 .......................................................................................................................................................................... 35 Figure 2-5 .......................................................................................................................................................................... 36 Figure 2-6 .......................................................................................................................................................................... 37 Figure 2-7 .......................................................................................................................................................................... 38 Figure 2-8 .......................................................................................................................................................................... 40 Figure 2-9 .........................................................................................................................................................................