10 CSR 10-6.010 - Ambient Air Quality Standards

PURPOSE: This rule is a compilation of standards for ambient air quality throughout Missouri in order to protect the public health and welfare. The U.S. Environmental Protection Agency has set National Ambient Air Quality Standards (NAAQS) for six (6) criteria pollutants (carbon monoxide, lead, nitrogen dioxide, ozone, particle pollution, and sulfur dioxide). Primary NAAQS provide public health protection and secondary NAAQS provide public welfare protection. In addition, Missouri has set standards for hydrogen sulfide and sulfuric acid.

Pollutant		Primary/Secondary Standard	Averaging Time	Level	Form	Reference Method
Carbon monoxide		Primary	8-hour	9 parts per million	Not to be exceeded more than once per year	As specified in 10 CSR 10-6.040(4)(C)
			1-hour	35 parts per million
Lead (2008)		Primary and secondary	Rolling 3-month average	0.15 micrograms per cubic meter	Not to be exceeded (see 10 CSR 10-6.040(4)(O) )	As specified in 10 CSR 10-6.040(4)(G)
Lead (1978)*		Primary	Calendar quarter mean	1.5 micrograms per cubic meter	Not to be exceeded	As specified in 10 CSR 10-6.040(4)(G)
Nitrogen dioxide		Primary	1-hour	100 parts per billion	98th percentile, averaged over 3 years	As specified in 10 CSR 10-6.040(4)(F)
		Primary and secondary	Annual	0.053 parts per million, equal to 53 parts per billion	Annual mean
Ozone (2008)		Primary and secondary	8-hour	0.075 parts per million	Annual fourth-highest daily maximum 8hour, averaged over 3 years (see 10 CSR 10-6.040(4)(N) )	As specified in 10 CSR 10-6.040(4)(D)
Ozone (1997)**		Primary	8-hour	0.08 parts per million	Annual fourth-highest daily maximum 8hour, averaged over 3 years (see 10 CSR 10-6.040(4)(I) )	As specified in 10 CSR 10-6.040(4)(D)
Particle pollution (2012)	Particulate matter 2.5 micron (PM2.5)	Primary	Annual	12 micrograms per cubic meter	Annual mean, averaged over 3 years	As specified in 10 CSR 10-6.040(4)(L)
		Secondary	Annual	15 micrograms per cubic meter	Annual mean, averaged over 3 years
		Primary and secondary	24-hour	35 micrograms per cubic meter	98th percentile, averaged over 3 years (see 10 CSR 10-6.040(4)(M) )
	Particulate matter 10 micron (PM10)	Primary and secondary	24-hour	150 micrograms per cubic meter	Not to be exceeded more than once per year on average over 3 years (see 10 CSR 10-6.040(4)(K) )	As specified in 10 CSR 10-6.040(4)(J)
Particulate matter 2.5 micron (PM2.5) (1997)***		Primary	Annual	15 micrograms per cubic meter	Annual mean, averaged over 3 years	As specified in 10 CSR 10-6.040(4)(L)
Sulfur dioxide (2010)		Primary	1-hour	75 parts per billion	99th percentile of 1-hour daily maximum, averaged over 3 years	As specified in 10 CSR 10-6.040(A)
		Secondary	3-hour	0.5 parts per million, equal to 500 parts per billion	Not to be exceeded more than once per year
Sulfur dioxide (1971)****		Primary	Annual	0.03 parts per million	Annual mean	As specified in 10 CSR 10-6.040(A)
		Primary	24-hour	0.14 parts per million	Not to be exceeded more than once per year
Hydrogen sulfide		State only	1/2-hour	0.03 parts per million (42 micrograms per cubic meter)	Not to be exceeded over 2 times in any 5 consecutive days	As specified in 10 CSR 10-6.040(5)
			1/2-hour	0.05 parts per million (70 micrograms per cubic meter)	Not to be exceeded over 2 times per year	As specified in 10 CSR 10-6.040(5)
Sulfuric acid		State only	1-hour	30 micrograms per cubic meter	Not to be exceeded more than once in any 2 consecutive days	As specified in 10 CSR 10-6.040(6)
			24-hour	10 micrograms per cubic meter	Not to be exceeded more than once in any 90 consecutive days	As specified in 10 CSR 10-6.040(6)

*The 1978 lead standard remains in effect until one (1) year after an area is designated for the 2008 standard, except that in areas designated nonattainment for the 1978 standard, the 1978 standard remains in effect until implementation plans to attain or maintain the 2008 standard are approved.

**The 1997 ozone standard and related implementation rules remain in place.

***The 1997 particulate matter 2. 5 micron ( PM 2. 5 ) standard remains in effect until one (1) year after an area is designated for the 2012 standard , except that in areas designated nonattainment for the 1997 standard, the 1997 standard remains in effect until implementation plans to attain or maintain the 2012 standard are approved.

****The 1971 annual and 24-hour sulfur dioxide standards remain in effect until one (1) year after an area is designated for the 2010 standard , except in areas designated nonattainment for the 1971 standards, where the 1971 standards remain in effect until implementation plans to atta in or maintain the 2010 standard are approved.

Notes

10 CSR 10-6.010

AUTHORITY: section 643.050, RSMo Supp. 2013. Original rule filed Aug. 16, 1977, effective Feb. 11 , 1978. For intervening history, please consult the Code of State Regulations. Amended: Filed Nov. 15, 2013, effective July 31, 2014.