4. PM10 Concentration (μg/m3)
Comparison of PM Design Values and PM10 Concentrations for the Same Day for Exceedances of the Proposed PM NAAQS
Monitor
Year
PM10-2.5
Design Value (μg/m3)
PM10 Concentration (μg/m3)
Percent
Equivalent PM10 NAAQS
Tucson Orange Grove
2002 72 76
94.7% 74
Nogales
2000 77 92
83.7% 84 98
104
94.2%
Douglas
2001
101
125
80.8% 87
2003
114
151
75.5% 93
Phoenix Super Site
134
167
80.2%
1999
150
164
91.5%
153
160
95.6% 73

5. Phoenix Area Visibility Index
Excellent < 15 dv
Good 15 – 20 dv
Fair 21 – 24 dv
Poor 25 – 28 dv
Very Poor > 28 dv
All Poor visibility days < 30 μg/m3
2/3rd Very Poor visibility days < 30 μg/m3

6. November 21, 2005 11am 14.3 ug/m3 26dv/19mi – Poor

7. December 21, 2005 noon 30.3 ug/m3 31dv/11mi – Very Poor