Chapter 2	"Maximum 24-Hour, 98th Percentile, and Annual PM2.5 Concentrations by Air Basin"					Table 2-15
AIR BASIN	2003 Maximum 24-Hr Concentration in micrograms/cubic meter		98th Percentile 24-Hr Conc. (ug/m3)**	2003 Average of Quarterly Means in micrograms/cubic meter**		
	State	National		State	National	
Great Basin Valleys Air Basin	44.0	44.0	8.0			
Lake County Air Basin	21.9	21.9	15.1	4.4	4.4	
Lake Tahoe Air Basin	27.4	21.0	19.0	7.2	7.2	
Mojave Desert Air Basin	28.0	28.0	24.0	9.4	11.4	
Mountain Counties Air Basin	54.0	43.0	40.0	8.6	13.3	
North Central Coast Air Basin	15.9	15.9	14.0	7.3	7.4	
North Coast Air Basin	36.1	36.1	15.2	7.4	7.3	
Northeast Plateau Air Basin	10.0	10.0				
Sacramento Valley Air Basin	73.2	65.0	43.0	15.9	12.2	
Salton Sea Air Basin	153.6	65.1	24.9	11.4	11.4	
San Diego Air Basin	239.2	239.2	46.9	14.4	15.5	
San Francisco Bay Area Air Basin	56.1	56.1	37.4	11.7	11.7	
San Joaquin Valley Air Basin	84.5	67.8	56.0	24.8	19.7	
South Central Coast Air Basin	116.0	116.0	33.4	12.4	14.2
South Coast Air Basin	121.2	121.2	76.6	24.8	24.8

"*  The table lists the highest value for each statistic. Within an air basin, the highest value for each statistic may reflect a different site."					
"** These statistics and determination of their validity are calculated according to the methods specified in 40 CFR Part 50, Appendix N. Validity is based on the number of measurements available per quarter and therefore, "					
"depends on data completeness. Both the 98th percentile concentration and the average of quarters concentration relate to the national PM2.5 standards, while only the average of quarters concentration relates to the State PM2.5 standard."