One-Hour Ozone High Value Days for 2009
as of January 6

In July 1997, the U. S. Environmental Protection Agency (EPA) announced a new National Ambient Air Quality Standard for ground-level ozone. The EPA is phasing out and replacing the previous one-hour standard with a new eight-hour standard to protect public health against longer exposure to the air pollutant.

A community will meet the new standard when the three-year average of the fourth-highest daily maximum eight-hour concentration measured at each monitoring site is less than 85 parts per billion.

Use the selection boxes below to customize this report. You may select a different year, a different sorting order, or a different report format. Click on the Generate Report button once you have made your selections. All times shown are in 24-hour format and are Local Standard Time. These times correspond to the beginning of the hourly average.

Year	Sort By	Report Format

Highlight with AQI colors

The table below lists the one-hour ozone concentrations measured in 2009 in each community where IDEM measures ozone that exceeds the one-hour standard. All ozone measurements are in parts per billion. Concentrations are color-highlighted based on the EPA-defined Air Quality Index colors. (See Interpreting the AQI.)

2009 -- Sorted by Maximum Value
Location	Region	CAMS	AQS	Date	Time	Value	POC	Hours Exceeded
There are no one-hour ozone exceedances recorded for 2009.
POC (Parameter Occurrence Code): a code used to correctly separate data from multiple instruments at one site.

PLEASE NOTE: This data has not been verified by the IDEM and may change. This is the most current data, but it is not official until it has been certified by our technical staff. Data is collected from IDEM ambient monitoring sites and may include data collected by other outside agencies.

Interpreting the AQI

Each NAAQS pollutant has a separate AQI scale, with an AQI rating of 100 corresponding to the concentration of the Federal Standard for that pollutant. Additional information about the AQI and how it can be used is available from the EPA Exit

The AQI scale is divided into the following categories:

Air Quality
	Good	Moderate	Unhealthy (for sensitive groups)	Unhealthy	Very Unhealthy	Hazardous
The AQI Air Quality Scale

One-Hour Ozone High Value Days for 2009as of January 6

Interpreting the AQI

One-Hour Ozone High Value Days for 2009
as of January 6