Smoke School Information in Vermont

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

Pending Acceptance.

Vermont Visible Emissions / Opacity Standard

The opacity limit for Vermont is 20% opacity, exceedable only for periods aggregating <=6 min in any hour; at no time greater than 60% opacity (Ringelmann No. 3); wood-fired equipment <=40 HP rated output exempt, as established under Vt. APCR Sec. 5-211(2).

Compliance is demonstrated via EPA Method 9 (40 CFR Part 60, Appendix A); Vermont DEC AQCD observer certification required.

Averaging period: Aggregate >6 minutes in any 1 hour may not exceed 20% opacity

Vermont's visible emissions standard (§ 5-211(2)) prohibits emissions exceeding 20% opacity for periods aggregating more than 6 minutes in any 1 hour and caps opacity at 60% at no time. An exception for soot blowing allows exceedances for ≤30 minutes per 24-hour period. Wood fuel burning equipment ≤3 MMBtu/hr is exempt from this section.

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.