The Environmental Protection Agency (EPA) has decided to partially approve and partially disapprove parts of North Dakota's regional haze plan (SIP) for its second implementation period. This decision was made because certain aspects of the plan, such as its long-term strategy and goals for reasonable progress, did not meet the necessary requirements under the Clean Air Act. Specifically, North Dakota relied on visibility thresholds that the EPA found unreasonable, which led to rejecting feasible and cost-effective controls on pollution sources like Coyote Station and Antelope Valley. However, other elements of the plan, such as calculations of visibility conditions and monitoring strategies, were approved.
Simple Explanation
The EPA checked North Dakota's plan for cleaning up the sky and said "yes" to some parts and "no" to others because they didn't think the plan would help the air enough. They liked some of the ways North Dakota wanted to measure the air but thought they could do a better job at making the air clearer.