Environmental Services Program

Circle Street Site

Site Operator: Missouri Department of Natural Resources' Environmental Services Program

Pollutants Monitored: Lead (Pb)

Lead (Pb)

Updated: Historical data only sampling was discontinued September 2009

National Ambient Air Monitoring Standard:

Three-Month Average

Lead is sampled on a 24-hour basis, one sample every sixth day. The rolling three-month average must not exceed 0.15 µg/m3. (Final rule signed Oct. 15, 2008)

Quarterly Average

The quarterly average must not exceed 1.5 µg/m3.

Previous standard was a three-month average of 1.5 ug/m3 (micrograms per cubic meter).

For more information please see the following link http://epa.gov/air/lead/actions.html

Exceedances allowed without a violation being recorded: None

Disclaimer: The following table is a summary of Lead data (through 2008) calculated using the previous Lead National Ambient Air Quality Standards regulations, which compares a quarterly average to1.5 μg/m3.  Data was calculated using EPA standard conditions of ambient temperature and barometric pressure.  Data in this table, from Jan. 1, 2009 to the present, is calculated at local conditions using daily average temperature and barometric pressure.  All data in this table is historical and will not be updated.

Lead (Pb)

The units for all averages in this chart are micrograms per cubic meter.
Year Number of
3-Month Average
24-Hour Average
Fourth Quarter
0 .92 5.44
2007 0 1.07 9.04
2008 0 1.1419 9.3610
2009 (Site discontinued September 2009)
First Quarter 0 .65373 10.3300
Second Quarter 0 .65220
Third Quarter 0 .57998

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