Ozone Design Value Calculation using AirNow Data

This tool uses AirNow daily maximum 8-hour ozone data to estimate an 8-hour ozone design value (ppb) for the selected AQS site and design value year.

• Enter an AQS Site ID or click a site on the map to select it.
• Choose a design value year (the tool will use that year and the previous two years).
• Set an ozone exclusion threshold in ppb (days above this level are excluded).
• Click Submit to calculate the 3-year design value and completeness.

Note: Results are for screening and visualization only and may not match official EPA regulatory design values.