Air SIP Revisions & Other State Plans for Control of Air Pollution
SIP Revisions and Other State Air Quality Plans
The tables below provide details on the status of recent DEEP State Implementation Plan (SIP) revisions and other State Air Quality Plans. EPA also maintains similar status tables for Infrastructure SIPs submitted by DEEP and regulations approved into Connecticut's SIP.
SIP Revisions
| Federal Citation | SIP Revisions | Supporting Documents | Status |
Date of Latest Action* (Year/Month/Day) |
|---|---|---|---|---|
| Clean Air Act Sections 182 and 184 | Reasonably Available Control Measures and Reasonably Available Control Technology Analysis under the 2008 8-Hour Ozone National Ambient Air Quality Standard - Reclassification to Severe Nonattainment for the CT portion of the NY-NJ-CT Nonattainment Area. | Final RACT SIP NY-NJ-CT Clean Air Act Sections 182 and 184 | Submitted to EPA | 2025/11/20 |
| Clean Air Act Section 182 and 40 CFR 51.165 | Certification of Adequacy of the Connecticut State Implementation Plan to Satisfy the Nonattainment New Source Review Requirements of the Clean Air Act for the 2008 8-Hour Ozone National Ambient Air Quality Standard - Reclassification to Severe Nonattainment for the CT portion of the NY-NJ-CT Nonattainment Area. | NNSR Certification Clean Air Act Section 182 and 40 CFR 51.165 | Submitted to EPA | 2025/11/20 |
| Clean Air Act Section 182(a)(3)(B) | Emission Statement Certification for the 2008 Ozone National Ambient Air Quality Standard. | Final Emission Statement Certification 2008 Clean Air Act Section 182(a)(3)(B) | Submitted to EPA | 2025/11/20 |
| Clean Air Act Section 182 | DEEP is proposing a revision to the CT SIP to include Consent Order No. 8383, issued to Algonquin Gas Transmission, LLC, which establishes emission standards that are determined to satisfy RACT for VOC pursuant to RCSA 22a-174-32(e)(1)(D) for the facility located at 252 Shunpike Road, Cromwell, Middlesex County, CT. Enclosures to this notice include: Consent Order No. 8383, Technical Support Document and appendices A-G, public notice, certification of public participation, hearing report, letters to the docket. |
Algonquin Cromwell RACT Order Clean Air Act Section 182 Algonquin Cromwell RACT TSD-for notice Clean Air Act Section 182 Algonquin Clean Air Act Section 182 Appendix A-Algonquin CO 2525 Clean Air Act Section 182 Appendix B-RACT plan part 1 Clean Air Act Section 182 Appendix C-RACT plan part 2 Clean Air Act Section 182 Appendix D-RACT plan part 3 Clean Air Act Section 182 Appendix E-RACT plan part 4 Clean Air Act Section 182 Appendix F-RACT plan part 5 Clean Air Act Section 182 Appendix G-RACT plan part 6 Clean Air Act Section 182 Public notice Clean Air Act Section 182 Hearing certification Clean Air Act Section 182 Hearing report Clean Air Act Section 182 EPA Clean Air Act Section 182 Demetriades Clean Air Act Section 182 Shneider Clean Air Act Section 182 |
Submitted to EPA | 2024/12/10 |
| Clean Air Act Section 177 | The Environmental Protection Agency (EPA) is approving a State Implementation Plan revision submitted by the State of Connecticut on December 14, 2015. Connecticut updated its motor vehicle emission regulations to adopt California’s Advanced Clean Car (ACC) I program that includes California’s low emission vehicle (LEV) III criteria pollutant standards and zero-emission vehicle (ZEV) sales requirements through the 2025 model year, and greenhouse gas (GHG) emissions standards that commence in the 2017 model year. Connecticut ensured that its regulations are identical to the California standards for which a waiver has been granted, as required by the Clean Air Act (CAA). | SIP Revision 2015 Clean Air Act Section 177 | EPA Approval Clean Air Act Section 177 | 2024/07/15 |
| Clean Air Act Sections 182 and 184 | Reasonably Available Control Measures and Reasonably Available Control Technology Analysis under the 2015 8-Hour Ozone National Ambient Air Quality Standard - Reclassification to Moderate Nonattainment for the Greater Connecticut Nonattainment Area | Final RACT SIP Greater Connecticut Clean Air Act Sections 182 and 184 | Submitted to EPA | 2023/05/23 |
| Clean Air Act Section 182 40 CFR 51.165 |
Certification of Adequacy of the Connecticut State Implementation Plan to Satisfy the Nonattainment New Source Review Requirements of the Clean Air Act for the 2015 8-Hour Ozone National Ambient Air Quality Standard Reclassification of the Greater Connecticut Nonattainment Area to Moderate Nonattainment | NNSR Certification Clean Air Act Section 182, 40 CFR 51.165 | Submitted to EPA | 2023/05/23 |
| Clean Air Act Section 182(a)(3)(B) | Emission Statement Certification for the 2015 Ozone National Ambient Air Quality Standard | Final Emission Statement Certification 2015 Clean Air Act Section 182(a)(3)(B) | Submitted to EPA | 2023/05/23 |
| Clean Air Act, Sec. 182 & 184 | Final RACT SIP Revision for the Serious Designation for the 2008 Ozone NAAQS and the Marginal/Moderate Designations for the 2015 Ozone NAAQS | SIP Revision 2008 Clean Air Act, Sec. 182 & 184 | Submitted to EPA | 2020/12/29 |
| 40 CFR 51.114 & 51.165 | Certification of Adequacy of the CT SIP to Satisfy the NNSR Requirements of the CAA for the 2008 8-Hour Ozone NAAQS Reclassification to Serious Nonattainment and the 2015 8-Hour Ozone NAAQS Initial Classification | NNSR Adequacy Demonstration 40 CFR 51.114 & 51.165 | Submitted to EPA | 2020/12/29 |
| Clean Air Act, Sec. 110(a)(2) | 2015 Ozone NAAQS: Good Neighbor SIP | SIP Revision Clean Air Act, Sec. 110(a)(2) | Submitted to EPA | 2018/12/06 |
| Clean Air Act, Sec. 110 (a)(1) & (2) | 2015 Ozone NAAQS: Infrastructure SIP Revision | SIP Revision Clean Air Act, Sec. 110 (a)(1) & (2) | Submitted to EPA | 2018/09/07 |
| Clean Air Act, Sec. 110(a)(1) & (2), 172 (b) & 182(b) | 1997 & 2008 Ozone NAAQS and 2012 Fine Particle NAAQS: Low Emission Vehicle SIP | Latest SIP Revision (Attachment C) Previous EPA Approval Clean Air Act, Sec. 110(a)(1) & (2), 172 (b) & 182(b) |
Proposed Approval Clean Air Act, Sec. 110(a)(1) & (2), 172 (b) & 182(b) | 2018/1/16 |
| Clean Air Act, Sec. 172 (b) & 182(b) | 1997 and 2008 Ozone NAAQS: Attainment Demonstration for the Connecticut Portion of the NY-NJ-CT Nonattainment Area | SIP Revision 1997 and 2008 Ozone NAAQS Clean Air Act, Sec. 172 (b) & 182(b) Approval Regarding the 1997 Standard Clean Air Act, Sec. 172 (b) & 182(b) Partial Approval Regarding the RACM, RFP, Contingency, Mobile Budgets and Inventories Clean Air Act, Sec. 172 (b) & 182(b) |
Proposed Approval of the I/M Program. Clean Air Act, Sec. 172 (b) & 182(b) | 2019/02/01 |
| 40 CFR 51.1114 & 40 CFR 51.165 | 2008 Ozone NAAQS: NNSR Adequacy Determination | SIP Revision 2008 40 CFR 51.1114 & 40 CFR 51.165 | EPA Approval 40 CFR 51.1114 & 40 CFR 51.165 | 2018/03/19 |
| Clean Air Act, Sec. 172 (b) & 182(b) | 2008 Ozone NAAQS: Attainment Demonstration for the Greater Connecticut Nonattainment Area | SIP Revision 2008 Ozone NAAQS: Attainment Demonstration Clean Air Act, Sec. 172 (b) & 182(b) Partial Approval Regarding the RACM, RFP, Contingency, Mobile Budgets and Inventories Clean Air Act, Sec. 172 (b) & 182(b) |
Proposed Approval of the I/M Program. Clean Air Act, Sec. 172 (b) & 182(b) | 2019/02/01 |
| Clean Air Act, Sec. 110 & 184 | SIP Revision: Amendment of Municipal Waste Combustor Regulation | SIP Revision and attachments Clean Air Act, Sec. 110 & 184 | Proposed approval Clean Air Act, Sec. 110 & 184 | 2017/04/06 |
| 40 CFR 51.102 | SIP Revision: Removal of Obsolete Single-Source VOC RACT Orders | SIP Revision 40 CFR 51.102 Attachments SIP Revision: Removal of Obsolete |
Proposed approval 40 CFR 51.102 | 2017/05/01 |
| 40 CFR 51.102 | Withdrawal: VOC RACT Order #8246 from SIP Submittal | Letter to EPA 40 CFR 51.102 Attachments Withdrawal: VOC RACT Order |
Proposed approval 40 CFR 51.102 | 2017/05/01 |
| Clean Air Act, Sec. 182(a)(1) and 172(c)(3) | 2011 Periodic Emissions Inventory (PEI) | Cover letter to EPA Clean Air Act, Sec. 182(a)(1) and 172(c)(3) 2011 PEI Clean Air Act, Sec. 182(a)(1) and 172(c)(3) Certification of Public Review Process Clean Air Act, Sec. 182(a)(1) and 172(c)(3) Response to Comments Clean Air Act, Sec. 182(a)(1) and 172(c)(3) |
Submitted to EPA | 2016/03/09 |
| Clean Air Act, Sec. 110 (a)(1) & (2) | 2012 PM2.5 NAAQS: Infrastructure SIP Revision. | SIP Revision and Attachments Clean Air Act, Sec. 110 (a)(1) & (2) | EPA Approval Clean Air Act, Sec. 110 (a)(1) & (2) | 2018/08/31 |
| Clean Air Act, Sec. 202(a)(6) and 40 CFR 51.126 | SIP Revision Concerning the Transfer and Dispensing of Gasoline (Stage I/Stage II Vapor Recovery) | Final SIP Submittal 2017/12/15 Clean Air Act, Sec. 202(a)(6) and 40 CFR 51.126 | EPA Approval Clean Air Act, Sec. 202(a)(6) and 40 CFR 51.126 | 2017/12/15 |
| 40 CFR 51.308(g) | 2014 Regional Haze Five-Year Progress Report | Five-Year Progress Report 40 CFR 51.308(g) | Submitted to EPA | 2015/07/13 |
| Clean Air Act, Sec. 110 (a)(1) & (2) | 2008 Ozone NAAQS: Infrastructure Transport Requirements | Good Neighbor SIP Clean Air Act, Sec. 110 (a)(1) & (2) | EPA Completeness Determination Clean Air Act, Sec. 110 (a)(1) & (2) | 2015/06/16 |
| Clean Air Act, Sec. 182 & 184 | 2008 Ozone NAAQS: Reasonably Available Control Technology Analysis | Final RACT SIP Revision Clean Air Act, Sec. 182 & 184 Attachment 1 Clean Air Act, Sec. 182 & 184 (MS Excel) |
Approval Clean Air Act, Sec. 182 & 184 | 2017/08/30 |
| Clean Air Act, Sec. 110 (a) (1) & (2) | 2010 SO2 NAAQS: Infrastructure SIP Revision | Final SIP Submittal 2018/08/31 Clean Air Act, Sec. 110 (a) (1) & (2) | EPA Approval 2010 SO2 NAAQS: Infrastructure SIP Revision | 2018/08/31 |
| Clean Air Act, Sec. 110 (a) (1) & (2) | 2010 NO2 NAAQS: Infrastructure SIP Revision | Final SIP Submittal 2010 NO2 NAAQS Clean Air Act, Sec. 110 (a) (1) & (2) | EPA Approval Clean Air Act, Sec. 110 (a) (1) & (2) | 2018/08/31 |
| Clean Air Act, Sec. 110 (a) (1) & (2) | 2008 Ozone NAAQS: Infrastructure SIP Revision | Final SIP Submittal 2008 Ozone NAAQS: Infrastructure SIP Revision | EPA Approval Clean Air Act, Sec. 110 (a) (1) & (2) | 2018/08/31 |
| 40 CFR 51 | Repeal of two Air Quality Regulations | SIP Revision 40 CFR 51 | Submitted to EPA | 2012/11/21 |
| Clean Air Act Section 183 | Reasonably Available Control Technology Update Clean Air Act Section 183 | Control Measures Guidance Documents Clean Air Act Section 183 | Submitted to EPA | 2012/11/21 |
| 50 CFR Part 51.102 | Modifications to Trading Agreements and Orders 8187 and 8242 to remove certain restriction on the use of continuous emission reduction credits 50 CFR Part 51.102 Final Submission CT SIP amendment |
Trading Order 8187 50 CFR Part 51.102 Trading Order 8242 50 CFR Part 51.102 |
Submitted to EPA | 2012/11/01 |
| Clean Air Act, Sec. 110 (a) (1) & (2) | 1997 PM2.5 NAAQS: Infrastructure SIP | Final SIP Submittal NAAQS: Infrastructure SIP | EPA Approval 1997 PM2.5 NAAQS: Infrastructure SIP | 2016/07/05 |
| Clean Air Act, Sec. 110 (a) (1) & (2) | SIP Revision: NSR revision with regard to PM2.5 | Letter to EPA with NSR Revisions Clean Air Act, Sec. 110 (a) (1) & (2) | Submitted to EPA | 2012/10/09 |
| 40 CFR 51, Appendix V, Section 2. 1(a) | Notification to Nearby States in Connecticut's Prevention of Significant Deterioration Permit Program Revisions to RCSA section 22a-174-2a(b)(5) and (6) |
Final SIP Submittal 2012/09/27 40 CFR 51, Appendix V, Section 2. 1(a) | Submitted to EPA | 2012/09/27 |
| Clean Air Act Sections 107(d)(3)(E) and 175A | 1997 and 2006 Fine Particulate Matter (PM2.5) NAAQS: Redesignation Request and Maintenance SIP Clean Air Act Sections 107(d)(3)(E) and 175A | Information provided within SIP Revision link to the left | Submitted to EPA | 2012/06/22 |
| 40 CFR 51.102 & R.C.S.A. Sec. 22a-174-22 & 32 |
Final Submission NOx & VOC Orders | Submission Package 40 CFR 51.102, R.C.S.A. Sec. 22a-174-22 & 32 (PDF) | Submitted to EPA | 2011/11/31 |
| Clean Air Act Section 110(a)(1) and (2) | 2008 Lead NAAQS: Adequacy Determination of the Connecticut State Implementation Plan Clean Air Act Section 110(a)(1) and (2) | Information provided within SIP Revision link to the left | EPA Approval Clean Air Act Section 110(a)(1) and (2) | 2018/08/31 |
| EPA Control Techniques Guidelines | Reasonably Available Control Technology Update EPA Control Techniques Guidelines Modification of SIP Submittal EPA Control Techniques Guidelines |
Control Measures Guidance Documents EPA Control Techniques Guidelines | Submitted to EPA | 2010/04/29 |
| 40 CFR 51.308(b) & (e) | 2009 Regional Haze SIP (Final) 40 CFR 51.308(b) & (e) | MANE-VU Reports 40 CFR 51.308(b) & (e) | EPA Approval 40 CFR 51.308(b) & (e) | 2014/07/10 |
| Clean Air Act, Sec. 172(c) & 110 (a)(1)&(2) | 1997 Fine Particulate Matter (PM 2.5) NAAQS: Attainment Demonstration Clean Air Act, Sec. 172(c) & 110 (a)(1)&(2) | Information provided within SIP Revision link to the left | Submitted to EPA | 2008/11/18 |
| Clean Air Act, Sec. 172 (c) & 182(a)(3) | 2002 Periodic Ozone and Carbon Monoxide Emissions Inventory Clean Air Act, Sec. 172 (c) & 182(a)(3) | Information provided within SIP Revision link to the left | Submitted to EPA | 2008/02/01 |
| Clean Air Act, Sec. 172 (b) & 182(b) | 1997 Ozone NAAQS: Attainment Demonstration Clean Air Act, Sec. 172 (b) & 182(b) | Final SIP Revision Clean Air Act, Sec. 172 (b) & 182(b) | EPA Approval Clean Air Act, Sec. 172 (b) & 182(b) | 2018/05/25 |
| Clean Air Act, Sec. 110 (a) (1) & (2) | 1997 Ozone NAAQS: Adequacy Determination of the Connecticut State Implementation Plan Clean Air Act, Sec. 110 (a) (1) & (2) | Information provided within SIP Revision link to the left | EPA Approval 1997 Ozone NAAQS: Adequacy | 2011/09/06 |
| 40 CFR 51 Subpart S | 2007 Inspection and Maintenance Program SIP Revision 40 CFR 51 Subpart S | Information provided within SIP Revision link to the left | EPA Approval 40 CFR 51 Subpart S | 2008/12/05 |
| 40 CFR 51.123(a)(2) & (ee) |
CAIR Implementation Plan, Final Submission CAIR SIP Revision 40 CFR 51.123(a)(2) & (ee) (PDF, 8.22 MB) |
2009 Allocations 40 CFR 51.123(a)(2) & (ee) (PDF) 2009 Allocations Round 2 and New Units 40 CFR 51.123(a)(2) & (ee) (PDF) 2010 Allocations 40 CFR 51.123(a)(2) & (ee) (PDF) 2010 Allocations Round 2 and New Units 40 CFR 51.123(a)(2) & (ee) (PDF) 2011 Allocations 40 CFR 51.123(a)(2) & (ee) (PDF) 2011 Allocations Round 2 and New Units 40 CFR 51.123(a)(2) & (ee) (PDF) 2012 Allocations Round 1 40 CFR 51.123(a)(2) & (ee) (PDF) 2012 Allocations Round 2 and New Units 40 CFR 51.123(a)(2) & (ee) (PDF) 2013 Allocations Round 1 40 CFR 51.123(a)(2) & (ee) (PDF) 2013 Allocations Round 2 40 CFR 51.123(a)(2) & (ee) (PDF) 2014 Allocations Round 1 40 CFR 51.123(a)(2) & (ee) (PDF) 2015 Allocations Round 1 40 CFR 51.123(a)(2) & (ee) (PDF) |
EPA Approval 40 CFR 51.123(a)(2) & (ee) | 2008/01/24 |
| Clean Air Act, Sec. 110(a)(2)(D) | Transport SIP Revision | Final Submission to EPA (March 13, 2007) Clean Air Act, Sec. 110(a)(2)(D) (PDF) Draft Submission Cover Letter (December 22, 2006) Clean Air Act, Sec. 110(a)(2)(D) (PDF) |
EPA Approval Clean Air Act, Sec. 110(a)(2)(D) | 2008/06/06 |
| 69 FR 40028 & 70 FR 24280 | Final Early PM2.5 Transportation Conformity Emission Budgets SIP Revision 69 FR 40028 & 70 FR 24280 (PDF) | Hearing Report 69 FR 40028 & 70 FR 24280 (PDF) | EPA Approval 69 FR 40028 & 70 FR 24280 | 2007/06/20 |
| 40 CFR 51.102 & R.C.S.A. Sec. 22a-174-32 |
Final Submission VOC RACT Orders | Submission Package 40 CFR 51.102, R.C.S.A. Sec. 22a-174-32 (PDF, 239MB) | Submitted to EPA | 2007/06/23 |
| 40 CFR 51.102 | CT- NOx and VOC RACT | Submitted to EPA | 2006/12/06 | |
| 40 CFR 51.102 | CT- Revisions to Record Keeping, Monitoring and Visible Emissions Rule | Submitted to EPA | 2004/12/01 | |
| 40 CFR 51.102 | CT- Single Source NOx Credits for RACT | SIP 12-02-2002 40 CFR 51.102 (PDF) | Submitted to EPA | 2002/12/02 |
*Final actions are listed by effective date. Proposals and submittals are listed by date of action.
Other State Air Quality Plans
| Federal Citation | Plan Topic | Supporting Documents | Status |
|---|---|---|---|
| 40 CFR 58.10 | Connecticut Annual Air Monitoring Plans 40 CFR 58.10 | Submitted to EPA on July 1 each year. | |
| Clean Air Act Sec. 129 | Revision to Connecticut State Municipal Waste Combustor Plan | July 7, 2008 Rule Amendment Marked to show revisions Clean Air Act Sec. 129 Hearing Report Clean Air Act Sec. 129 |
Rule Amendment originally submitted to EPA August 21, 2008, subsequent submission February 27, 2009. EPA approval pending. |
| 40 CFR 51.102 & 40 CFR 60.24(h) |
Connecticut Clean Air Mercury State Plan 40 CFR 51.102 & 40 CFR 60.24(h) | Submitted to EPA November 2, 2007 |
Content Last Updated on November 21, 2025