Smoke School Information in Idaho

Idaho Acceptance Status for VirtualOpacity^® — EPA ALT-152A

Accepted.

Conditions: Conditionally accepted. DEQ stipulates that certifications will only be accepted if the observer has previously conducted initial certification, or follow-up recertification, via the traditional field method.
Exceptions will be considered on a case-by-case basis (e.g., if field certification is unavailable when needed, or if travel is not feasible due to financial restrictions or safety concerns).
For further information, contact Emanuel Ziolkowski at Emanuel.Ziolkowski@deq.idaho.gov.

Idaho Acceptance Letter »

Idaho Visible Emissions / Opacity Standard

The opacity limit for Idaho is 20% opacity for periods aggregating more than 3 min in any 60-min period; pre-1969 carve-out applies ONLY to 5 named source categories, not a general grandfather clause, as established under IDAPA 58.01.01.625; category exemptions at .625.01 (5 named pre-Jan 24, 1969 source types only); exempted-source standard at .625.02.

Compliance is demonstrated via IDEQ procedures nearly identical to EPA Method 9; Idaho-specific certification required.

Averaging period: Max 3 minutes in any 60-minute period above 20%

Idaho requires its own observer certification (valid 6 months) in addition to EPA Method 9 training. Idaho-specific modifications to Method 9 procedures apply.

Last verified July 8, 2026

Note: Regulations change — always verify current requirements with your state's air quality agency before making compliance decisions. This page is for informational purposes and is not legal advice; consult a qualified attorney or environmental compliance professional for guidance specific to your facility.