# Air Plan Approval; Missouri Redesignation Request and Associated Maintenance Plan for the Jefferson County 2010 SO2 1-Hour NAAQS Nonattainment Area
> **Rule** · Final rule. · Published 2022-01-28 · Effective 2022-02-28 · 87 FR 4508
## Document
- **Document number:** 2022-01645
- **Category:** air-emissions
- **Federal Register citation:** 87 FR 4508
- **CFR reference:** 40 CFR 52
- **Publication date:** 2022-01-28
- **Effective date:** 2022-02-28
- **State:** MO
- **EPA docket:** EPA-R07-OAR-2021-0391
## Abstract

On December 27, 2017, the State of Missouri submitted a request for the Environmental Protection Agency (EPA) to redesignate the Jefferson County, Missouri, 2010 1-hour sulfur dioxide (SO<INF>2</INF>) National Ambient Air Quality Standard (NAAQS) nonattainment area to attainment and to approve a State Implementation Plan (SIP) revision containing a maintenance plan for the area. The State provided supplemental information on: May 15, 2018; February 7, 2019; February 25, 2019; and April 9, 2021. In response to these submittals, the EPA is taking the following final actions: Approve the State's plan for maintaining attainment of the 2010 1-hour SO<INF>2</INF> primary standard in the area; and approve the State's request to redesignate the Jefferson County SO<INF>2</INF> nonattainment area to attainment for the 2010 1-hour SO<INF>2</INF> primary standard.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2022/01/28/2022-01645/air-plan-approval-missouri-redesignation-request-and-associated-maintenance-plan-for-the-jefferson)
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