(a) Regional haze. The regional haze State Implementation Plan (SIP) revisions submitted on September 23, 2008 and August 3, 2010, and supplemented on September 27, 2011 are partially approved and partially disapproved.

(1) The identification of sources that are eligible for Best Available Retrofit Technology (BART) is approved, with the exception of the 6A Boiler at the Georgia-Pacific Crossett Mill, which is BART eligible.

(2) The identification of sources subject to BART is approved, with the exception of the 6A and 9A Boilers at the Georgia-Pacific Crossett Mill, which are both subject to BART.

(3) The following BART determinations are disapproved:

(i) The sulfur dioxide (SO2), nitrogen dioxide (NOX), and particulate matter (PM) BART determinations for the Arkansas Electric Cooperative Corporation Bailey Plant Unit 1 and the AECC McClellan Plant Unit 1;

(ii) The SO2 and NOX BART determinations for the American Electric Power Flint Creek Plant Boiler No. 1;

(iii) The NOX BART determination for the natural gas firing scenario and the SO2, NOX, and PM BART determinations for the fuel oil firing scenario for the Entergy Lake Catherine Plant Unit 4;

(iv) The SO2 and NOX BART determinations for both the bituminous and sub-bituminous coal firing scenarios for the Entergy White Bluff Plant Units 1 and 2;

(v) The BART determination for the Entergy White Bluff Plant Auxiliary Boiler;

(vi) The SO2 and NOX BART determinations for the Domtar Ashdown Mill Power Boiler No. 1; and

(vii) The SO2, NOX and PM BART determinations for the Domtar Ashdown Mill Power Boiler No. 2.

(4) The Arkansas Regional Haze Rule, (APCEC Regulation 19, Chapter 15), is partially approved and partially disapproved such that:

(i) The requirement under Reg. 19.104(B) for BART installation and operation as expeditiously as practicable, but no later than 5 years after EPA approval of the Arkansas Regional Haze State Implementation Plan is partially approved and partially disapproved, such that the partial approval is for the BART determinations we are approving and the partial disapproval is for the BART determinations we are disapproving;

(ii) The requirement under Reg. 19.1504(B) for BART installation and operation no later than 6 years after the effective date of the State regulation is disapproved;

(iii) Reg. 19.1505 (A)(1) and (2), (B), (C), (D)(1) and (2), (E), (F)(1) and (2), (G)(1) and (2), (H), (I)(1) and (2), (J)(1) and (2), (K), (L), (M)(1), and (N) are disapproved;

(iv) the Reg. 19.1506 requirement to demonstrate compliance with the BART limits listed in Reg. 19.1505 (A)(1) and (2), (B), (C), (D)(1) and (2), (E), (F)(1) and (2), (G)(1) and (2), (H), (I)(1) and (2), (J)(1) and (2), (K), (L), (M)(1), and (N) is disapproved; and

(v) The remaining portions are approved.

(5) The regional haze long term strategy under 40 CFR 51.308(d)(3) is partially approved and partially disapproved.

(6) The reasonable progress goals are disapproved.

(b) Interstate Transport. The portion of the SIP pertaining to adequate provisions to prohibit emissions from interfering with measures required in another state to protect visibility, submitted on March 28, 2008, and supplemented on September 27, 2011, is partially approved and partially disapproved.

(1) The Arkansas Regional Haze Rule, (APCEC Regulation 19, Chapter 15), is partially approved and partially disapproved such that:

(i) The requirement under Reg. 19.104(B) for BART installation and operation as expeditiously as practicable, but no later than 5 years after EPA approval of the Arkansas Regional Haze State Implementation Plan is partially approved and partially disapproved, such that the partial approval is for the BART determinations we are approving and the partial disapproval is for the BART determinations we are disapproving;

(ii) The requirement under Reg. 19.1504(B) for BART installation and operation no later than 6 years after the effective date of the State regulation is disapproved;

(iii) Reg. 19.1505 (A)(1) and (2), (B), (C), (D)(1) and (2), (E), (F)(1) and (2), (G)(1) and (2), (H), (I)(1) and (2), (J)(1) and (2), (K), (L), (M)(1), and (N) are disapproved;

(iv) The Reg. 19.1506 requirement to demonstrate compliance with the BART limits listed in Reg. 19.1505 (A)(1) and (2), (B), (C), (D)(1) and (2), (E), (F)(1) and (2), (G)(1) and (2), (H), (I)(1) and (2), (J)(1) and (2), (K), (L), (M)(1), and (N) is disapproved; and

(v) The remaining portions are approved.

(2) [Reserved]

(c) [Reserved]

(d) Measures Addressing Partial Disapproval of Portion of Interstate Visibility Transport SIP for the 1997 8-hour ozone and PM2.5 NAAQS. The deficiencies identified in EPA's partial disapproval of the portion of the SIP pertaining to adequate provisions to prohibit emissions in Arkansas from interfering with measures required in another state to protect visibility, submitted on March 28, 2008, and supplemented on September 27, 2011 are satisfied by § 52.173.

(e) Measures addressing best available retrofit technology (BART) for electric generating unit (EGU) emissions of nitrogen oxides (NOX). The BART requirements for EGU NOX emissions are satisfied by § 52.184 and the Arkansas Regional Haze NOX SIP Revision approved February 12, 2018, 83 FR 5927.

(f) Other measures addressing reasonable progress. The reasonable progress requirements for NOX emissions are satisfied by the Arkansas Regional Haze NOX SIP Revision approved February 12, 2018.

(g) Regional Haze Phase II SIP Revision. A portion of the Regional Haze Phase II SIP Revision submitted on August 8, 2018, is approved as follows:

(1) Identification of the 6A Boiler at the Georgia-Pacific Crossett Mill as BART-eligible and the determination based on the additional information and technical analysis presented in the SIP revision that the Georgia-Pacific Crossett Mill 6A and 9A Boilers are not subject to BART.

(2) SO2 and PM BART for the AECC Bailey Plant Unit 1; SO2 and PM BART for the AECC McClellan Plant Unit 1; SO2 BART for the AEP/SWEPCO Flint Creek Plant Boiler No. 1; SO2 BART for Entergy White Bluff Units 1 and 2; SO2, NOX, and PM BART for the Entergy White Bluff Auxiliary Boiler; and the prohibition on burning of fuel oil at Entergy Lake Catherine Unit 4 until SO2 and PM BART determinations for the fuel oil firing scenario are approved into the SIP by EPA.

(3) The focused reasonable progress analysis and the reasonable progress determination that no additional SO2 and PM controls are necessary under the reasonable progress requirements for the first implementation period.

(4) The long-term strategy is approved with respect to sources other than the Domtar Ashdown Mill. This includes the BART emission limits contained in the SIP revision and the SO2 emission limit of 0.60 lb/MMBtu under the long-term strategy provisions for Independence Units 1 and 2 based on the use of low sulfur coal.

(5) Consultation and coordination in the development of the SIP revision with the FLMs and with other states with Class I areas affected by emissions from Arkansas sources.

(h) Arkansas Regional Haze Phase III SIP Revision. The Arkansas Regional Haze Phase III SIP Revision submitted on August 13, 2019, is approved as follows:

(1) The clear weight of evidence determination that the BART alternative for Power Boilers No. 1 and 2 satisfies all of the applicable regional haze provisions set forth in 40 CFR 51.308(e)(2)(i) to (iv) for the Domtar Ashdown Mill with respect to SO2, NOX, and PM10.

(2) The regional haze program-specific plantwide conditions 32 to 43 from section VI of Permit #0287-AOP-R22 are approved for Power Boilers No. 1 and 2 for the Domtar Ashdown Mill, which contain SO2, NOX, and PM10 emission limits and conditions for implementing the BART alternative.

(3) The approval of the withdrawal of the current PM10 BART determination of 0.07 lb/MMBtu for Power Boiler No. 1 in the 2008 Arkansas Regional Haze SIP and replacement with the PM10 BART alternative limit in the Arkansas Regional Haze Phase III SIP Revision.

(4) The reasonable progress components under 40 CFR 51.308(d)(1) pertaining to the Domtar Ashdown Mill are approved.

(5) The long-term strategy component pertaining to the Domtar Ashdown Mill that includes the emission limits and schedules of compliance component under 40 CFR 51.308(d)(3)(v)(3) is approved.

(6) Consultation and coordination in the development of the SIP revision with the FLMs and with other states with Class I areas affected by emissions from Arkansas sources, as required under 40 CFR 51.308(i)(2) and 40 CFR 51.308(d)(3)(i), is approved.

(i) Portions of the Arkansas 2015 O3 NAAQS Interstate Transport SIP Revision and Arkansas Regional Haze SO2 and PM SIP Revision addressing Visibility Transport. The portion of the Arkansas 2015 O3 NAAQS Interstate Transport SIP revision addressing the visibility transport requirements of CAA section 110(a)(2)(D)(i)(II) for Arkansas for the 2006 24-hour PM2.5 NAAQS; the 2012 annual PM2.5 NAAQS; the 2008 and 2015 eight-hour O3 NAAQS; the 2010 one-hour NO2 NAAQS; and the 2010 one-hour SO2 NAAQS are approved. The visibility transport portion of the Arkansas Regional Haze SO2 and PM SIP revision, as supplemented by the Arkansas 2015 O3 NAAQS Interstate Transport SIP revision, is also approved.

(j) Revisions to the Arkansas Pollution Control and Ecology Commission's (APC&EC) Rule No. 19, Chapter 15. Revisions to APC&EC Rule No. 19, Chapter 15, submitted on June 22, 2022, are approved.