40 CFR § 52.834 - Control strategy: Sulfur dioxide.

---
identifier: "/us/cfr/t40/s52.834"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 52.834 - Control strategy: Sulfur dioxide."
title_number: 40
title_name: "Protection of Environment"
section_number: "52.834"
section_name: "Control strategy: Sulfur dioxide."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "52"
part_name: "APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7401"
cfr_part: "52"
---


# 52.834 Control strategy: Sulfur dioxide.

(a) *Approval.* On April 21, 1997, the Iowa Department of Natural Resources (IDNR) submitted a maintenance plan and redesignation request for the Muscatine County nonattainment area for the 1971 SO<sub>2</sub> national ambient air quality standard (NAAQS). The maintenance plan and redesignation request satisfy all applicable requirements of the Clean Air Act.

(b) *Determination of attainment by the attainment date.* As of May 9, 2022, the EPA has determined that the Muscatine, Iowa SO<sub>2</sub> nonattainment area has attained the 2010 1-hour SO<sub>2</sub> primary NAAQS by the applicable attainment date of October 4, 2018.

(c) *Redesignation to attainment.* EPA has determined, as of November 18, 2025, that the Muscatine County 2010 SO<sub>2</sub> nonattainment area is redesignated to attainment of the 2010 SO<sub>2</sub> 1-hour National Ambient Air Quality Standard (NAAQS) in accordance with the requirements of Clean Air Act (CAA) section 107(d)(3) and has approved its maintenance plan and supplemental modeling demonstration analyses as meeting the requirements of CAA section 175A.

[87 FR 20331, Apr. 7, 2022, as amended at 90 FR 51559, Nov. 18, 2025]