Top 4 Summary: Select Pollutant, Years, & Area

Step 1: Select a Pollutant
Step 2: Select a Year Range
Step 3: Select a Summary Type¹ Summarize by Site
Summarize by County
Summarize by Air Basin
Summarize by 8-Hour Ozone Planning Area
Step 4: Select a County²
 OR an Air Basin²
 OR an 8-Hr Ozone Plan Area²
 OR Statewide²
Step 5: Submit Your Selections



Choose "Summarize by Site" to view air quality statistics for specific locations. Users unfamiliar with air basins or ozone planning areas may wish to select the "Summarize by Site" option.


If you choose to summarize by site, you may choose to have iADAM list the monitoring sites that operated within one of California's counties, within an air basin, within an 8-hour ozone planning area, or within the state during the year ranged selected.

Air Basins are usually multi-county regions of the state that have similar meteorological and geographic conditions. Air basins boundaries typically follow county boundaries, but there are several instances within the state where air basin boundaries fall within a county, dividing the county between two or more air basins.

8-Hour Ozone Planning Areas are regions of the state that the U.S. Environmental Protection Agency has defined for the purpose of planning for the attainment of a national 8-hour ozone ambient air quality standard. These planning areas include many geographical configurations, including multiple counties, single counties, or portions of counties.