http://www.sltrib.com/news/environment/2017/08/25/advocates-growing-impatient-as-utahs-new-plan-for-cleaner-air-falls-behind-schedule/

“Advocates growing impatient as Utah’s new plan for cleaner air falls behind schedule. Utah will probably miss EPA’s December deadline for latest plan to control pollution in Wasatch Front’s inversions. State officials have notified the Environmental Protection Agency that Utah is likely to miss yet another air-quality deadline, leading some clean-air advocates to criticize regulators for a lack of action.
Utah’s latest plan for reducing spikes of small-particulate pollution over the Wasatch Front was due to the EPA in December. But at this point, state officials say it’s unlikely they can meet that deadline and still provide adequate opportunity for public comment.”