Indiana gets a pass on its regional haze plan, delaying cleanup for national parks

US environmental regulators are proposing to approve Indiana's plan to reduce regional haze, even though the plan does not meet all federal requirements. This means Indiana will not have to make further changes to its pollution controls for the next decade, impacting air quality in national parks and wilderness areas.

The Clean Air Act requires states to reduce pollution that causes regional haze, which obscures views in national parks. This approval means Indiana's existing pollution controls, primarily from coal-fired power plants, are deemed sufficient for the next ten years. Other states with similar plans may now expect similar leniency, potentially slowing down efforts to improve air quality across the country.