About Tribal Minor New Source Review Permitting in Region 9

EPA’s Pacific Southwest (Region 9) implements and enforces federal environmental laws in Arizona, California, Hawaii, Nevada, the Pacific Islands, and 148 Tribal Nations.

View Pending and Completed Tribal NSR Actions

EPA has authority to issue Non-attainment New Source Review Permits (major non-attainment NSR) and minor New Source Review permits (minor NSR) on Tribal Lands under 40 CFR 49. Note that EPA issues Prevention of Significant Deterioration permits under 40 CFR 52.21 on Tribal Lands as well. For a listing of PSD permits, view Prevention of Significant Deterioration (PSD) Permits Issued by Region 9.

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Update to Application Submittal Instructions

To submit the application electronically, applicants may use Central Data Exchange (CDX). First-time users will need to register with CDX. The CDX platform will also be used for any permit reporting requirements.

Alternatively, please mail a signed application using certified mail (do not request signature) to:

Air and Radiation Division
Permits Office (Air-3-1)
U.S. EPA, Region 9
75 Hawthorne Street
San Francisco, CA 94105

AND email a copy of the application and the certified mail tracking number to provide notification of delivery receipt to R9AirPermits@epa.gov.

For more information on how to use CDX, submit a Request for Coverage, registration, or permit application, please contact:

Catherine Valladolid
valladolid.catherine@epa.gov
(415) 947-4103

About Tribal Minor New Source Review Permitting

EPA promulgated the Review of New Sources and Modifications in Indian Country on July 1, 2011. The final rule is a federal implementation plan (FIP) that outlines preconstruction permitting of air pollution control requirements for industrial facilities located in Indian Country.

The FIP includes two New Source Review (NSR) rules for the protection of air quality in Indian country. One of those rules, known as the Tribal Minor NSR Rule, applies to new industrial facilities or modifications at existing industrial facilities with projected emissions that are more than the minor NSR thresholds but less than the major NSR thresholds, which are generally 100 to 250 tons per year (tpy).

The FIP allows EPA Region 9 to review applications for and issue minor NSR permits to industrial facilities within the federally-recognized external boundaries of Reservations in the Region (Arizona, California, Hawaii, and Nevada). The FIP also allows EPA to delegate that authority to Tribes in the Region that request it and are able to demonstrate appropriate capability to implement the FIP. Additionally, the FIP can be replaced by an EPA-approved Tribal implementation plan (TIP).

The Tribal Minor NSR program provides three options for obtaining permits:

  • Site-Specific Permits: includes case-by-case determinations of the source emission limits as well as any control technology requirements
  • General Permits: permits that have been developed for a number of similar equipment types or facilities to simplify the permit issuance process for facilities; or
  • Synthetic Minor Permits: applies to a facility that has the potential to emit pollutants in amounts that are at or above major source thresholds, but has voluntarily accepted emission limits so that its potential emissions are below those thresholds, allowing the facility to avoid more stringent major NSR requirements of the Clean Air Act, such as Prevention of Significant Deterioration (PSD), and Title V Operating Permit requirements. This option is available to different types of facilities, including those that emit hazardous air pollutants so that they will not be subject to National Emissions Standards for Hazardous Air Pollutants, also known as Maximum Available Control Technology (MACT) standards, for major sources.

The permit issuance process includes public notice and comment requirements, as well as administrative and judicial review provisions.

Minor NSR Thresholds

Your potential regulated air pollutant emissions must be greater than the thresholds in the table below and less than the major NSR thresholds.

Table 1 to 40 CFR 49.153. Minor NSR Thresholds a
Regulated NSR pollutantMinor NSR Thresholds for Non-Attainment Areas (tpy)Minor NSR Thresholds for Attainment Areas (tpy)
Carbon monoxide (CO)510
Nitrogen oxides (NOx)5 b10
Sulfur dioxide (SO2)510
Volatile Organic Compounds (VOC)2 b5
PM510
PM1015
PM2.50.63
Lead0.10.1
FluoridesNA1
Sulfuric acid mistNA2
Hydrogen sulfide (H2S)NA2
Total reduced sulfur (including H2S)NA2
Reduced sulfur compounds (including H2S)NA2
Municipal waste combustor emissionsNA2
Municipal solid waste landfill emissions
(measured as nonmethane organic compounds)		NA10
a If part of a Tribe's area of Indian country is designated as attainment and another part as nonattainment, the applicable threshold for a proposed facility or modification is determined based on the designation where the facility would be located. If the facility straddles the two areas, the more stringent thresholds apply.

b In extreme ozone nonattainment areas, section 182(e)(2) of the Act specifies that any change at a major facility that results in any increase in emissions is subject to permitting. In other words, any changes to existing major facilities in extreme ozone nonattainment areas must comply with a "0" tpy threshold, but that threshold does not apply to minor facilities.

Application Forms

Free viewers and readers are available to access documents on our website. If you encounter issues with assistive technology, please contact us.

We recommend contacting the EPA Region 9 Air Permits Section for a preliminary application meeting to ensure the correct application form and supplemental information is submitted. For example, your application could be delayed if it does not sufficiently address impacts to endangered species, cultural resources and/or air quality. Please contact EPA's Pacific Southwest for more information.

General Permits/Permits by Rule: see forms available on EPA's Tribal Minor New Source Review webpage

General Permits or Permits by Rule

General Permits or Permits by Rule are now available at EPA's Tribal Minor New Source Review web area for the following source categories:

A table of Region 9's completed permit actions can be found at Completed Region 9 Permit Actions.

Other Implementation Tools

Additional implementation tools can be found at EPA's Tribal Minor New Source Review web area.

Map of EPA's Pacific Southwest (Region 9)

Arizona, California, Hawaii,
Nevada, Pacific Islands,
148 Tribal Nations

Public Notice

EPA Pacific Southwest CAA Resources

CAA Permitting in EPA's Pacific Southwest

Resources

State/Tribal/Local Permitting Authorities

AZ | CA | HI | NV

National Supporting Resources

Air Permitting Policy & Guidance

Permitting Under the Clean Air Act

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Last updated on June 4, 2026