State Implementation Plans

The federal Clean Air Act requires states to submit plans to ensure the attainment and maintenance of national ambient air quality standards (NAAQS). The common term used to refer to these federally enforceable plans is "State Implementation Plans" or SIPs. The six criteria pollutants as defined by the U.S. Environmental Protection Agency (EPA) are carbon monoxide, lead, nitrogen dioxide, ozone, particulate matter, and sulfur dioxide. SIPs are also prepared to protect visibility at federal Class I areas consisting of national parks and wilderness areas. Vermont is considered a "Class I state" for Regional Haze planning due to the presence of the Lye Brook Wilderness Area in the southern Green Mountains.

The table below includes recently submitted or proposed SIP revisions.  Please use the contact information at the bottom of the page if you are seeking SIP related information that is not posted here.

SIP Revisions Federal Citation Relevant Documents Status
Inspection and Maintenance SIP Clean Air Act, Sec. 182(c)(3)(A), 184 (a), 184(b)(1)(A) and 40 C.F.R. Part 51, Subpart S

Public notice

Proposed draft

Submitted to EPA June 28, 2022.

Open for public comment April 29-June 8, 2022.

Public hearing June 1, 2022

Infrastructure and Good Neighbor SIP, 2015 Ozone NAAQS Clean Air Act, Sec. 110 (a)(1) & (2)

Final submittal

Hearing cancellation

Public notice

Proposed draft

Approved by EPA June 4, 2020, 85 FR 34357

Submitted to EPA November 20, 2019.

Regional Haze SIP: 2018-2028 40 CFR 51.308(b),(d) & (e)   In 60-day consultation period with Federal Land Management agencies. 8/12/2022
Reasonably Available Control Technology (RACT) SIP revision for the 2008 and 2015 ozone NAAQS Clean Air Act Sec. 184

Final submission

Proposed draft

Approved by EPA 11/26/2019, 84 FR 65009

Submitted to EPA September 6, 2018

Proposed May 23, 2018. Comment period closed July 16, 2018

Public Notice, No. 18P019

Infrastructure SIP for the 2012 Fine Particle (PM2.5) NAAQS, including Good Neighbor SIP for the interstate transport provision Clean Air Act, Sec. 110 (a)(1) & (2) Final submittal, I-SIP and Good Neighbor SIP

Approved by EPA June 29, 2018, 83 FR 30598

Submitted to EPA October 31, 2017

Infrastructure SIP for the 2008 Ozone, 2010 Nitrogren Dioxide, and 2010 Sulfur Dioxide NAAQS Clean Air Act, Sec. 110 (a)(1) & (2) Infrastructure SIP for 2008 Ozone, 2010 NO2, and 2010 SO2

Approved by EPA March 19, 2018, 83 FR 11884

EPA Approval and Conditional Approval, June 27, 2017, 82 FR 29005

Approval of Interstate Transport Elements for Ozone, October 13, 2016, 81 FR 70631

Submitted to EPA Nov. 2. 2015

Infrastructure SIP for the 2008 Lead NAAQS Clean Air Act, Sec. 110 (a)(1) & (2) Infrastructure SIP for the 2008 Lead NAAQS

Approved by EPA March 19, 2018, 83 FR 11884

EPA Approval and Conditional Approval, June 27, 2017, 82 FR 29005

Submitted to EPA July 29, 2014

Regional Haze Five-Year Progress Report 40 CFR 51.308(g) & (h)

Regional Haze 5-year Progress Report

Submittal cover letter

Appendix F: Status of Emissions from 167 Key Stacks (Excel file)


Approved by EPA December 18, 2017

Federal Register Citation: 82 FR 59969

Submitted to EPA February 29, 2016

Regional Haze State Implementation Plan 40 CFR 51.308(b),(d) & (e)


Regional Haze SIP

SIP Attachments

Approved by EPA May 22, 2012

Federal Register Citation: 77 FR 30212

Submitted to EPA August 31, 2009



For more information about Vermont's State Implementation Plans, please contact Bennet Leon.