40 CFR § 81.20 - Metropolitan Cincinnati Interstate Air Quality Control Region.
---
identifier: "/us/cfr/t40/s81.20"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 81.20 - Metropolitan Cincinnati Interstate Air Quality Control Region."
title_number: 40
title_name: "Protection of Environment"
section_number: "81.20"
section_name: "Metropolitan Cincinnati Interstate Air Quality Control Region."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "81"
part_name: "DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7401,"
regulatory_source: "36 FR 22421, Nov. 25, 1971, unless otherwise noted."
cfr_part: "81"
---
# 81.20 Metropolitan Cincinnati Interstate Air Quality Control Region.
The Metropolitan Cincinnati Interstate Air Quality Control Region (Ohio-Kentucky-Indiana) is revised to consist of the territorial area encompassed by the boundaries of the following jurisdictions (including the territorial area of all municipalities (as defined in section 302(f) of the Clean Air Act, 42 U.S.C. 1857h(f) geographically located within the outermost boundaries of the area so delimited):
In the State of Kentucky: Boone County, Campbell County, Carroll County, Gallatin County, Grant County, Kenton County, Owen County, Pendleton County.
In the State of Indiana: Dearborn County, Ohio County.
In the State of Ohio: Butler County, Clermont County, Hamilton County, Warren County.