40 CFR § 52.2571 - Classification of regions.

---
identifier: "/us/cfr/t40/s52.2571"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 52.2571 - Classification of regions."
title_number: 40
title_name: "Protection of Environment"
section_number: "52.2571"
section_name: "Classification of regions."
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"
---


# 52.2571 Classification of regions.

The Wisconsin plan was evaluated on the basis of the following classifications:

|  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- |
| Duluth (Minnesota)-Superior (Wisconsin) Interstate | I | II | III | III | III |
| North Central Wisconsin Intrastate | II | III | III | III | III |
| Lake Michigan Intrastate | II | III | III | III | III |
| Southeast Minnesota-La Crosse (Wisconsin) Interstate | II | IA | III | III | III |
| Southern Wisconsin Intrastate | II | III | III | III | III |
| Southeastern Wisconsin Intrastate | I | II | III | III | I |
| Rockford (Illinois)-Jamesville-Beloit (Wisconsin) Interstate | II | III | III | III | III |
| Metropolitan Dubuque Interstate | I | III | III | III | III |

[37 FR 10902, May 31, 1972, as amended at 39 FR 16348, May 8, 1974; 45 FR 2322, Jan. 11, 1980]