When an applicant voluntarily asks, a county may permit and certify emission reduction credits for portable source components and mobile sources such as vehicle fleets, and voluntary permits that certify these credits may last up to 20 years.
Official title: emissions; reduction credits; counties
- September 12, 2026
What changes
BeforeThe state environmental department had original jurisdiction over air pollution from portable sources and mobile sources.
NowAfter a voluntary request from an applicant, a county may claim concurrent (shared) jurisdiction over components of portable sources and over mobile sources in the county. This is only for issuing, revising or enforcing a permit that certifies emission reduction credits.
BeforeAir quality permit law did not apply to motor vehicles or to agricultural vehicles and equipment used in normal farm operations.
NowThat exemption does not stop the state director or a county control officer from issuing a permit that requires emission reductions from motor vehicles, agricultural vehicles or equipment, mobile sources or nonroad engines. This applies only if the applicant voluntarily applied and agreed to those reductions when the permit was issued.
BeforeState air quality permits were issued for 5 years.
NowVoluntary permits issued only to certify emission reduction credits are given at the permitting authority's discretion. They remain subject to the usual permit rules and enforcement, and may last up to 20 years.
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NowTaking part in a county credit program is voluntary. Only mobile source fleets with a base of operations in a nonattainment area (an area not meeting federal air standards) can be certified. Once a county issues the permit or permit revision, it is binding on the applicant.
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NowIf a law, rule or state air plan commitment later makes it mandatory for on-road vehicle fleets to take part in the credit program, a control officer may not certify any new surplus emission reduction credits for mobile sources.
Who it affects
- Businesses and other operators of vehicle fleets based in nonattainment areas who choose to seek emission reduction credits
- Operators of portable sources
- Owners of agricultural vehicles or equipment and nonroad engines who voluntarily seek such permits
- County air quality control officers and boards of supervisors
- Arizona Department of Environmental Quality
What you need to do
Nothing. Taking part is voluntary. Applicants who choose to get a credit permit are bound by its terms once it is issued.
What the law doesn't answer
- What emission reduction credits are used for or how they can be sold or traded
- What fees, if any, apply to these credit permits
- How a county formally claims concurrent jurisdiction
- Which areas of Arizona count as nonattainment areas
- How the state and county coordinate when both have jurisdiction over the same source
This summary describes the law as enacted. Later laws, court rulings or referendum petitions can change the picture. Check the official text for the current wording.