Utah must now prove its air pollution does not harm other states

US environmental regulators are moving to approve Utah's plan for controlling air pollution that drifts into other states. This means Utah must show its emissions do not prevent downwind states from meeting federal air quality standards.

Air pollution does not respect state lines. For decades, states have argued over who is responsible for dirty air when the source is in one state and the harm is in another. This approval means Utah is now legally bound to prevent its pollution from interfering with other states' ability to maintain clean air.