DEQ is the state agency delegated by the federal government to issue air quality permits in Idaho. Permits are required by the federal Clean Air Act and set the conditions under which facilities that generate air pollution may operate. The purpose of permits is to ensure compliance with all state and federal air pollution control rules, which are designed to protect public health and the environment.

Any business or industry (source) in Idaho that emits, or has the potential to emit, pollutants into the air is required to have an air pollution control permit from DEQ. Permits are issued when new sources begin operation and when existing sources modify their facilities.

DEQ's Air Quality Division issues several different types of permits based on the emissions from the facility and/or emitting source. Permits require sources to comply with all health- and technology-based standards established by the U.S. Environmental Protection Agency (EPA) and the Rules for Control of Air Pollution in Idaho (pdf on Department of Administration Web site). If an applicant demonstrates compliance with all applicable federal and state air pollution laws and regulations, DEQ is required by law to issue an air permit.

The permit and accompanying technical analysis include detailed information on the type(s) of pollutants released, how much may be released, how the facility will comply with the air pollution control rules, and how the pollutants will be monitored. Violation of the permit provisions can result in enforcement action.

The following four types of permits are issued: permit to construct (PTC), Tier I (Title V) operating permit, Tier II operating permit, and permit by rule (PBR).

 Permit to Construct

An air quality PTC is required prior to construction or modification of stationary sources, such as buildings, structures, and other installations that emit, or may emit, pollutants into the air. A PTC is also required for certain portable equipment such as generators, crushing equipment, asphalt plants, and concrete batch plants. Click here for more information on PTCs.

 Tier I (Title V) Operating Permit

A Tier I operating permit (also known as a Title V operating permit) is required by the federal Clean Air Act for major sources. Major sources are sources that emit, or may emit, 100 or more tons of any regulated air pollutant per year, 10 or more tons per year of any one hazardous air pollutant (HAP), or 25 or more tons per year of any combination of hazardous air pollutants. Minor or area sources that are subject to New Source Performance Standards and National Emission Standards for Hazardous Air Pollutants also may be required to obtain Tier I permits in the future, although they are only required to register with DEQ at this time. Click here for more information on Tier I permits.

 Tier II Operating Permit

Certain facilities that emit air pollution in Idaho may choose to limit production and/or hours of operation, thus lowering their potential to emit pollutants below Tier I permit thresholds and qualifying them for a Tier II operating permit. In other cases, DEQ may require certain sources of air pollution to obtain Tier II permits. The fees for Tier II permits are lower and the reporting requirements less complex than those required for Tier I operating permits. Click here for more information on Tier II permits.

 Permit by Rule

A PBR is a streamlined registration process that enables qualified applicants to bypass the need to obtain a PTC or Tier II operating permit before beginning operation. Currently, the opportunity to obtain a PBR is available to nonmetallic mineral processing plants (portable rock crushing facilities) and certain dairies. PBRs for other industries are being considered.

› Click here for more information on portable rock crushing PBRs.
› Click here for more information on dairy PBRs.