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Air Quality State Implementation Plans (SIPs)

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SIPs are a collection of state and local regulations and plans to achieve healthy air quality under the Clean Air Act. State and local agencies must involve the public in the adoption process before SIP elements are submitted to EPA for federal approval or disapproval, and EPA must provide an opportunity for public comment before taking action on each SIP submittal.

This Web site contains action logs for the federally enforceable applicable SIPs in Arizona, California, Nevada, Hawaii, and the Pacific Islands. Action logs list the state and local air pollution regulations that EPA has incorporated into the applicable SIP under section 110 of the Clean Air Act. In some cases, the actual text of the regulations may be attached. The contents of the action log are described below.

Action Log Terms and Abbreviations

Adoption Date: Describes when the rule was adopted by the state or local air pollution agency.

Submittal Date: Describes when the rule was submitted to EPA by the state agency.

Final FR Date: The publication date of EPA's final rulemaking notice, listed in the Federal Register. Rules generally become effective 30 days after publication.

FR Citation: References the page number in the Federal Register of the rulemaking notice.

The EPA has attempted to assure that the action logs accurately reflect the actions published in the Federal Register. If there are discrepancies, however, the Federal Register is the official record.

For each state and local agency, a file titled "notes" summarizes related EPA rulemaking actions other than rule approvals. These actions include rule disapprovals, negative declarations, nonattainment area plan actions, redesignations, rule rescissions, or other details of the action.

Links to Locally Enforceable Regulations

Text of locally enforceable regulations are available at the links provided below. In many cases, these regulations have been approved by EPA as a component of the applicable SIP. Since these links are not maintained by EPA, we cannot ensure the accuracy and timeliness of their content. Additionally, most state or local agencies are implementing some rules or versions of rules not listed in these action logs. This occurs when rules and rule amendments are not submitted and/or approved by EPA.

Links to Criteria for SIP Approval

The applicable SIP contains many kinds of provisions including, for example, nonattainment plans, conformity regulations, permit rules and prohibitory rules.The criteria used for evaluating new SIP revisions and additions varies depending on the type of provision. Some relevant criteria are provided in the links below.

Links to Alternative Test Methods

Many SIP regulations refer to specific scientific methods for determining air pollution levels and other parameters. Many of these test methods are established by EPA and described in 40 CFR 60, Appendix A, but EPA has also approved the use of alternative test methods. A link to approved alternative test methods that may be used in SIP regulations is provided below.

Please note that unless otherwise noted in the approval letter, these alternative test methods are not approved for use in determining compliance with the New Source Performance Standards or the National Emissions Standards for Hazardous Air Pollutants.

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