Idaho Air Permitting Issues

Written October 17, 2019

Idaho does have a Title V permit program in place. A Title V operating permit (Tier I operating permit) is required for major sources with the potential to emit more than 100 tons of VOC per year, or 10 tons of one hazardous air pollutant (HAP) or 25 tons of a combination of Hazardous air pollutants are required to apply for a Title V permit. The state's program does contain provisions for a synthetic minor designation. Synthetic minors are those facilities that agree to federally enforceable limits that restrict their potential to emit to less than the major source threshold.

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 A facility owner or operator cannot commence construction or modification activities of a major source without first obtaining a construction permit. A permit to construct is not required if a facility has less than 100 tons per year of actual and potential VOC emissions; and the construction activities will not significantly increase the emissions from a major facility; and the construction will not have a net emission increase in any toxic air pollutant.