We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Regulations for Emissions from Vehicles and Engines

California Greenhouse Gas Waiver Request

On July 8, 2009, EPA granted a waiver of Clean Air Act preemption to California for its greenhouse gas emission standards for motor vehicles beginning with the 2009 model year.

The California Air Resources Board originally requested this waiver in December 2005. That request was denied by EPA on March 6, 2008. Early this year, the California Air Resources Board requested that EPA reconsider its waiver denial. Then, on January 26, 2009, President Obama signed a Presidential Memorandum, directing EPA to assess whether denial of the waiver based on California's application was appropriate in light of the Clean Air Act.

Learn more:

Waiver Process

The Clean Air Act gives California special authority to enact stricter air pollution standards for motor vehicles than the federal government’s. EPA must approve a waiver, however, before California’s rules may go into effect. Once California files a waiver request, EPA publishes a notice for public hearing and written comment in the Federal Register. The written comment period typically remains open for a period of time after the public hearing. Once the comment period expires, EPA reviews the comments and the administrator determines whether California has satisfied the law’s requirements for obtaining a waiver.

According to the Clean Air Act Section 209 – State Standards, EPA shall grant a waiver unless it finds that California:

  • was arbitrary and capricious in its finding that its standards are in the aggregate at least as protective of public health and welfare as applicable federal standards;
  • does not need such standards to meet compelling and extraordinary conditions; or
  • has proposed standards not consistent with Section 202(a) of the Clean Air Act.

You can read all the documents associated with this waiver request at www.regulations.gov (Or go to the main page for the regulations docket, select Advanced Search, then Docket Search, and type EPA-HQ-OAR-2006-0173 as the Docket ID). Below we have provided direct links to some of the relevant documents.

For extensive information about federal environmental laws, EPA regulations, significant guidance documents, and dockets — including how to search for rules and comment on them — see the Laws, Regulations, Guidance, and Dockets site.

Related Documents

Date Document
July 8, 2009 California State Motor Vehicle Pollution Control Standards; Notice of Decision Granting a Waiver of Clean Air Act Preemption for California's 2009 and Subsequent Model Year Greenhouse Gas Emission Standards for New Motor Vehicles (PDF) (42 pp, 280K, July 2009)
June 30, 2009 Executive Summary: EPA's Waiver Decision on California's Greenhouse Gas Emission Standards for New Motor Vehicles
February 12, 2009 Federal Register Notice: California State Motor Vehicle Pollution Control Standards; Greenhouse Gas Regulations; Reconsideration of Previous Denial of a Waiver of Preemption (Can be found at U.S. Government Printing Office)
January 21, 2009 Letter to EPA Administrator Jackson from Mary Nichols, Chairman of the California Air Resources Board Requesting EPA Reconsideration of March 6, 2008 Waiver Denial
March 6, 2008 Federal Register Notice: California State Motor Vehicle Pollution Control Standards; Notice of Decision Denying a Waiver of Clean Air Act Preemption for California's 2009 and Subsequent Model Year Greenhouse Gas Emission Standards for New Motor Vehicles (Can be found at U.S. Government Printing Office)
December 19, 2007 Letter to Governor Arnold Schwarzenegger from EPA Administrator Stephen Johnson Regarding California’s Request for a Waiver of Pre-emption for Its Greenhouse Gas Regulations
July 26, 2007 California Waiver Request/Greenhouse Gas Motor-Vehicle Emission Standards Search EPA Archive
Testimony by EPA Administrator Stephen Johnson before the Senate Environment & Public Works Committee
July 24, 2007 California’s Waiver Request to Control Greenhouse Gases Under the Clean Air Act Exit Congressional Research Service report RL34099.
May 11, 2007 Energy Security & Climate Change Search EPA Archive
Testimony by EPA Administrator Stephen Johnson before the House Committee on Transportation & Infrastructure
May 10, 2007 Federal Register Notice: Opportunity for Second Public Hearing (Can be found at U.S. Government Printing Office) announcing the location of the May 22, 2007, public hearing and announcing an additional public hearing.
April 30, 2007 Federal Register Notice: Opportunity for Public Hearing (Can be found at U.S. Government Printing Office)
February 21, 2007 Letter to Catherine Witherspoon from William Wehrum, EPA Acting Assistant Administrator for Air and Radiation, Regarding the Massachusetts v. EPA Case Pending Before the U.S. Supreme Court
December 21, 2005 Letter to EPA Administrator Stephen Johnson from Catherine Witherspoon of the California Air Resources Board Requesting a Waiver of Pre-emption for Its Greenhouse Gas Regulations
   Attachment 1: CARB Executive Order G-05-061
   Attachment 2: Support Documents

Regulations for Emissions from Vehicles and Engines Home