Maryland Heights

Environmental Services Program

Maryland Heights

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

County: Saint Louis Site ID: 29-189-0014

Pollutants Monitored: Ozone (O3)

Ozone (O3)

Updated: Quarterly.

National Ambient Air Monitoring Standard:

Eight-hour Standard
The three-year average of the fourth highest daily maximum eight-hour average must not be greater than 0.075 ppm (parts per million). To attain this standard, the three-year average of the fourth-highest daily maximum eight-hour average ozone concentrations measured at each monitor within an area over each year must not exceed 0.075 ppm. (Effective May 27, 2008).

Exceedances allowed without a violation being recorded:
The term exceedance does not apply to the eight-hour standard. The three-year average is used to determine designation of attainment or non-attainment.

Disclaimer: Yearly and quarterly data shown below has been subject to data review and validation procedures by the reporting agency. Monthly data and data shown graphically is raw, unreviewed and unvalidated data.

The units for all averages in this chart are parts per million.
Year	Number of Days Over Standard	Maximum 1-Hour Average	Maximum 8-Hour Average	Fourth Maximum 8-Hour Average
2012
Second Quarter	8	0.131	0.094	0.090
Third Quarter	15	0.131	0.094	0.090
2011	8	0.101	0.091	0.080
This site came under control of Missouri Department of Natural Resources' Environmental Services Program on October 1, 2011.
2010	6	0.095	0.080	0.76
2009	0	0.095	0.075	0.070
2008	1	0.093	0.078	.069
2007	10	0.116	0.103	.094
2006	3	0.111	0.092	.084
2005	10	0.111	0.097	.088

Inactive Pollutants

Nitrogen Dioxide (NO2)

Updated: All data shown is historical this instrument was shut down October 2010.

National Ambient Air Monitoring Standard: An annual average of 0.053 ppm (parts per million).

Exceedances allowed without a violation being recorded: None.

The units for all averages in this chart are parts per million.
Year	Number of Exceedances	Annual Average	Maximum 1-Hour Average
2005	0	0.0101	0.046
2006	0	0.0089	0.256
2007	0	0.0081	0.058
2008	0	0.0073	0.045
2009	0	0.0062	0.040
2010
Through Third Quarter	0	0.0068	0.043
Instrument shut down October 2010

Sulfur Dioxide (SO2)

Updated: All data shown is historical this instrument was shut down October 2010.

National Ambient Air Monitoring Standard: A three-hour average of 0.50 ppm (parts per million) and/or a 24-hour average of 0.14 ppm (parts per million) and/or an annual average of 0.03 ppm (parts per million). Data reported in three decimal places must be rounded to two decimal places.

Exceedances allowed without a violation being recorded: One per year.

The units for all averages in this chart are parts per million.
Year	Number of Exceedances	Annual Average	Maximum 24-Hour Average	Maximum 3-Hour Average	Maximum 1-Hour Average
2005	0	0.0025	0.009	0.035	0.056
2006	0	0.0027	0.012	0.034	0.045
2007	0	0.0027	0.013	0.030	0.042
2008	0	0.0021	0.013	0.044	0.069
2009	0	0.0022	0.009	0.030	0.054
2010
First Quarter	0	0.0024	0.011	0.048	0.054
Second Quarter	0
Third Quarter	0
Instrument shut down October 2010