SIP - General Page | Region 10 | US EPA

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SIP - General Page


An implementation plan is a set of programs and regulations to assure healthy air quality through the attainment and maintenance of the National Ambient Air Quality Standards (NAAQS). These plans can be developed by States, eligible Indian Tribes, or the EPA, depending on the entity with jurisdiction and the EPA’s approval in a particular area. For States, such plans, once approved by the EPA, are referred to as State implementation plans or SIPs. Similarly, for eligible Indian Tribes these plans, once approved, are called Tribal implementation plans or TIPs.

Section 110 of the Clean Air Act, 42 U.S.C. 7410, requires States to adopt Federally approved control strategies to minimize air pollution. The resulting body of regulations is known as a SIP. SIPs generally establish limits or work practice standards to minimize emissions of the criteria air pollutants or their precursors. The criteria air pollutants include sulfur dioxide, particulate matter, nitrogen oxides, lead, carbon monoxide, and ozone. The EPA has established standards, NAAQS, for these pollutants. SIPs also include special control strategies for nonattainment areas -- areas that are not meeting the NAAQS. These control strategies often include measures such as vehicle inspection and maintenance programs, lower gasoline vapor pressures, gas pump vapor recovery, and other reasonably available control technologies (RACT). SIPs also include preconstruction permit requirements for projects that may result in emission increases.

Sections 110 and 301(d) of the Clean Air Act and the EPA’s implementing regulation at 40 CFR part 49 provide for Tribal implementation of various Clean Air Act programs including TIPs. Eligible Indian Tribes can choose to implement certain Clean Air Act programs by developing and adopting a TIP and submitting the TIP to the EPA for approval.

Air Quality Control Plan Summaries*:

|-----Alaska---|--Idaho ---|---Oregon---|---Swinomish Tribe---|----Washington


Federally Approved Rules Online:

|----Alaska---|-- Idaho---|---Oregon---|---Swinomish Tribe---|---Washington


Other Links:
Federal Registers Online
Electronic Code of Federal Regulations
Developing a Tribal Implementation Plan
Online SIP Processing Manual
The Green Book Nonattainment Areas for Criteria Pollutants
Transportation Conformity
General Conformity



* In general, air quality control plan summaries have been provided for areas that have been designated nonattainment.

  • In most cases, SIPs and TIPs closely parallel the agency's own regulations. However, in certain cases there may be differences - for example, when a state has not submitted, or EPA has not approved, a revision to one of the state's regulations.
  • Due to the magnitude of the project to put the SIPs and TIPs online, questions may arise on an approved section. If such questions arise as to the content of the approved SIP or TIP or any portion thereof, the Federal Register approval action and the CFR will serve as the final determination. While we have taken care with the accuracy of the files accessible here, they are not "official" rules in the sense that they can be used before a court of law. Due to translation between formats, and the variations in display by web browsers, errors (including human errors) can occur. Please notify us at the email address below of any errors you find in the files.
  • Recently approved plans and older plans may not have summaries.
  • "State Effective Date" or "State Adoption Date" may refer to the effective date or adoption date of the local air agency.
  • Air Permit Program Delegation: There are two ways that an air agency in Region 10 can get the authority to issue PSD permits. An agency may submit PSD rules to EPA for approval into their State Implementation Plan (SIP). Or EPA may delegate PSD authority to an agency via a PSD Delegation Agreement. Alaska, Idaho and Oregon have PSD rules approved in their SIPs. Washington does not have PSD rules approved in their SIP program and PSD authority has been delegated to them from EPA via this PSD Delegation Agreement (PDF) (18 pp, 1MB). In most cases, a SIP closely parallels an agency's own regulations. However, in certain cases there may be differences - for example, when a state has not submitted, or EPA has not approved, a revision to one of the state's regulations.
  • Some of the files are in pdf format, which can be read by downloading the free Adobe Acrobat reader.

    Contact: Claudia Vergnani Vaupel,, (206) 553-6121

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