# Redesignation of Certain Unclassifiable Areas for the 2010 1-Hour Sulfur Dioxide (SO2) Primary National Ambient Air Quality Standard (NAAQS)
> **Rule** · Final rule. · Published 2021-07-16 · Effective 2021-08-16 · 86 FR 37683
## Document
- **Document number:** 2021-14376
- **Category:** air-emissions
- **Federal Register citation:** 86 FR 37683
- **CFR reference:** 40 CFR 81
- **Publication date:** 2021-07-16
- **Effective date:** 2021-08-16
- **EPA docket:** EPA-HQ-OAR-2020-0292
## Abstract

The Environmental Protection Agency (EPA) is redesignating the Lancaster County, Nebraska and Milam County, Texas unclassifiable areas initially designated during the EPA's Round 2 air quality designations for the 2010 1-Hour Sulfur Dioxide (SO<INF>2</INF>) Primary National Ambient Air Quality Standard (NAAQS). Specifically, the EPA now has sufficient information to determine that these unclassifiable areas in Nebraska and Texas are attaining the 2010 1-hour SO<INF>2</INF> primary NAAQS. Therefore, the EPA is redesignating these areas to attainment/ unclassifiable for the 2010 1-hour SO<INF>2</INF> primary NAAQS. The EPA is also approving these states' requests to redesignate the areas.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2021/07/16/2021-14376/redesignation-of-certain-unclassifiable-areas-for-the-2010-1-hour-sulfur-dioxide-so2-primary)
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