The Clean Air Act regulates lead as a criteria pollutant. The U.S. Environmental Protection Agency (EPA) sets National Ambient Air Quality Standards for lead (Pb). These standards include both primary standards to protect public health and secondary standards to protect the environment. EPA reviews pollutant standards every five years. Sometimes, a review results in a tightened standard. On Oct. 15, 2008, the EPA revised its standard for lead for the first time since the original 1978 lead standard was established. The revision strengthened the 1978 standard tenfold, lowering the standard for airborne lead from 1.5 micrograms per cubic meter of air (µg/m3) to 0.15 µg/m3.
The lead standards below include the state implementation plan elements developed for each of the standards and the relevant documents associated with the boundary designations. If you are looking for a document that is not available on our website, please submit a Open Records/ Sunshine Law Request. For more information about lead, visit the department's Lead in Missouri webpage.
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2008 Standard
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Three-month Rolling Average Lead Standard = 0.15 micrograms per cubic meter of air (µg/m3). The standard is not met if the three-month rolling average concentration exceeds that level once or more within a three-year period.
2008 Standard Boundary Designations
MoDNR Submittal Date MoDNR Action/Document EPA Date EPA Action/Document Dec. 3, 2009 2008 Lead Designation and Boundary Recommendations Nov. 22, 2011 Air Quality Designations for the 2008 Lead (Pb) National Ambient Air Quality Standards [76 FR 72097]
Effective: Dec. 31, 2011N/A N/A June 14, 2011 EPA 2011 Preliminary Decision to Designate Remainder of the State as Unclassifiable/ Attainment - 120-day letter for the second round designations N/A N/A June 11, 2010 EPA Response to Recommendations on 2008 National Ambient Air Quality Standards for Lead - 120-day letter for the first round designations 2008 Standard Herculaneum Actions
MoDNR Submittal Date MoDNR Action/Document EPA Date EPA Action/Document Sept. 1, 2021 MoDNR Response Letter to EPA Letter Regarding Monitoring Issues at Dunklin High School July 7, 2021 EPA Letter Regarding Herculaneum Violation of the 2008 Lead National Ambient Air Quality Standard
April 17, 2013 Oct. 20, 2014 Air Quality State Implementation Plans; Approval and Promulgation: Missouri; 2013 State Implementation Plan for the 2008 Lead Standard [79 FR 62572] 2008 Standard Buick Actions
MoDNR Submittal Date MoDNR Action/Document EPA Date EPA Action/Document Sept. 24, 2013 Modification to the Attainment Demonstration for the 2008 Lead National Ambient Air Quality Standard: Buick/ Viburnum Trend Lead Nonattainment Area Aug. 28, 2015 Approval and Promulgation of Air Quality Implementation Plans; Missouri; 2013 Missouri State Implementation Plan for the 2008 Lead Standard [80 FR 52190] April 17, 2013 Attainment Demonstration for the 2008 Lead National Ambient Air Quality Standard: Buick/ Viburnum Trend Lead Nonattainment Area 2008 Standard Exide Technologies-Canon Hollow Facility Actions
MoDNR Submittal Date MoDNR Action/Document EPA Date EPA Action/Document Oct. 15, 2014 Sept. 26, 2016 Approval of Air Quality Implementation Plans; Missouri State Implementation Plan for the 2008 Lead Standard [81 FR 65987] 2008 Standard Glover SIPs Actions
MoDNR Submittal Date MoDNR Action/Document EPA Date EPA Action/Document Oct. 7, 2020 Plan for Continued Attainment of the 2008 Lead Standard in Liberty and Arcadia Townships in Iron County: Doe Run-Glover Facility Pending Pending