ARB Logo California Map with Basin Highlighted
Basin by Basin Comparison of 1994 Ozone Data
Basin Name Days Standard Exceeded Ozone Concentrations in ppm
1 hour 8 hour
State
1hr
Federal
1hr
Federal
8hr**
Max
1hr
3 Year
4th High*
EPDC*
Max
8hr
3 Year Avg
3rd High*
  Great Basin Valleys 4 0 6 0.12 0.12 0.118 0.092 0.086
  Lake County 0 0 0 0.09 0.08 0.083 0.075 0.063
  Lake Tahoe 0 0 0 0.08 0.09 0.089 0.079 0.079
  Mojave Desert 137 77 124 0.18 0.19 0.189 0.155 0.143
  Mountain Counties 57 2 49 0.13 0.12 0.126 0.109 0.100
  North Central Coast 6 0 1 0.10 0.11 0.104 0.093 0.083
  North Coast 1 0 0 0.10 0.09 0.089 0.080 0.072
  Northeast Plateau 0 0 0 0.08 0.07 0.075 0.069 0.060
  Sacramento Valley 60 9 48 0.14 0.14 0.147 0.122 0.108
  Salton Sea 126 20 75 0.18 0.15 0.153 0.131 0.117
  San Diego 79 9 46 0.14 0.15 0.147 0.121 0.115
  San Francisco B.A. 13 2 4 0.13 0.12 0.116 0.097 0.089
  San Joaquin Valley 118 43 108 0.17 0.16 0.156 0.129 0.112
  South Central Coast 90 17 65 0.16 0.14 0.146 0.133 0.116
  South Coast 165 118 149 0.30 0.28 0.277 0.208 0.174
* The 3 year 4th high, 3 year average 3rd high, and Expected Peak Day Concentration (EPDC) are calculated based on data for 3 successive years, listed by the last year of the three year period.  The EPDC represents the ozone concentration expected to occur once per year.
** Proposed Federal Standard

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This page last revised on April 5, 1997

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