West Alton

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

Pollutants Monitored: Ozone (O3), Nitrogen Dioxide (NO2), Inhalable Particulate (PM2.5)

Ozone (O3)

Updated: Monthly April through October

National Ambient Air Monitoring Standard:

8-hour Standard
The three-year average of the fourth highest daily maximum eight-hour average must not be greater than .08 ppm (parts per million). Data reported in three decimal places must be rounded to two decimal places.

1-hour Standard 1970 to 1997-no longer applies to any area in Missouri.
A one-hour average of 0.12 ppm (parts per million).

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
1993	0	.116	not available	not available
1994	4	.147	not available	not available
1995	4	.154	not available	not available
1996	1	.135	not available	not available
1997	1	.131	not available	not available
1998	2	.140	not available	not available
1999	2	.149	not available	not available
2000	1	.125	not available	not available
2001	1	.139	not available	not available
2002	20	.130	.111	.099
2003	7	.109	.097	.091
2004	0	.094	.081	.077
2005	11	.122	.101	.089
2006	10	.126	.097	.091
2007	10	.130	.099	.089
2008
FIRST QUARTER	not available	not available	not available	not available
SECOND QUARTER	not available
THIRD QUARTER	not available

Graph of Recent Ozone (O3) Data
Graph of 03 PPM.

Nitrogen Dioxide (NO2)

Updated: Within 90 days after the end of a quarter.

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
1993	0	.013	.083
1994	0	.013	.080
1995	0	.011	.057
1996	0	.011	.062
1997	0	.011	.073
1998	0	.012	.057
1999	0	.012	.066
2000	0	.009	.047
2001	0	.010	.050
2002	0	.0096	.043
2003	0	.0087	.041
2004	0	.0082	.044
2005	0	.0086	.050
2006	0	.0083	.050
2007	0	.0083	.050
2008
THROUGH FIRST QUARTER	0	.0076	.044

Graph of Recent Nitrogen Dioxide (NO2) Data
Graph of N02 PPM.

Inhalable Particulate (PM2.5)

Updated: Within 90 days after the end of a quarter.

National Ambient Air Monitoring Standard: (24-hour samples; one taken every third day) A three year average of the 98th percentile 24-hour averages equal or greater than 35 ug/m³ (micrograms per cubic meter) and/or a three year average of annual averages equal or greater than 15.0 ug/m³ (micrograms per cubic meter).

Exceedances allowed without a violation being recorded: Two percent of daily observations

The units for all averages in this chart are micrograms per cubic meter.
YEAR	FIRST MAXIMUM 24-HOUR AVERAGE	SECOND MAXIMUM 24-HOUR AVERAGE	ANNUAL AVERAGE
1998	not available	not available	not available
1999	43.7	40.7	14.24
2000	35.2	34.8	14.89
2001	42.0	36.7	15.0
2002	40.3	38.4	14.2
2003	44.7	37.9	14.0
2004	35.8	32.4	11.89
2005	41.5	41.4	15.21
2006	31.4	27.9	11.55
2007	49.7	39.4	11.55
2008 (Instrument removed 2008)