For anyone involved in the first round of the Clean Air Act regional haze program, the U.S. Environmental Protection Agency’s (EPA) action on the first business day of 2024 came as no surprise: EPA proposed to disapprove the regional haze plan for Kansas. If the past is any indication of the future, this proposal foreshadows what will likely be many more regional haze state plan disapprovals over the next 12 months, given that EPA has already been hauled into court once again to force it back on schedule.

Among the many provisions of the Clean Air Act, the regional haze program is unique —

separate and apart from the more well-known health-based protections, its focus is purely aesthetic: eliminating man-made visibility impairment from national parks and wilderness areas, known as “Class I areas.” The program requires states to develop 10-year “state implementation plans” (SIPs) containing any measures necessary to make reasonable progress toward an EPA-designated, but nonbinding, goal of natural visibility conditions in all Class I areas by 2064.

In the first 10-year planning period, covering the years 2008-2018, the program proved highly controversial. EPA disapproved numerous western state SIPs and replaced them with more stringent federal plans, leading to significant litigation. In those cases, which by statute must go directly to the local U.S. Courts of Appeals, the judges largely deferred to EPA if the agency could show that a state’s plan did not hew to EPA’s preferred analytical framework, much of which is spelled out only in guidance.

EPA’s January 2 proposal to reject the Kansas SIP suggests history is poised to repeat itself in the second regional haze planning period. In preparing its second regional haze SIP, Kansas determined that no additional control measures were necessary because the state was already making reasonable progress toward natural visibility conditions due to the emission reductions required by its first regional haze SIP and other Clean Air Act requirements.

Specifically, Kansas noted that, while its emission sources may still have some impact on seven Class I areas (none of which are located in Kansas), its sources are already well-controlled, and the potential visibility impact attributable to Kansas sources is extremely small. In fact, according to the SIP, 17 other states have a greater impact on those same seven areas, and the greatest impact by any Kansas source is less than 1% of the total man-made visibility degradation.

When Kansas first released its round two SIP for review, neighboring states and the federal land managers in charge of the relevant Class I areas apparently agreed that there would be little benefit to visibility from further attempts to reduce emissions within the state. According to a letter Kansas penned to criticize EPA’s delay in approving the SIP, even EPA regional staff initially agreed the plan was sufficient. However, EPA’s January 2 notice proposes a rejection of the Kansas plan based on failure to follow EPA guidance regarding the development of a regional haze SIP.

To be fair to Kansas, that guidance has been difficult to follow. In some iterations of the guidance, including a draft released in 2016, EPA discouraged states from weighing the cost of additional emission controls against the visibility benefits those controls might provide. In other iterations, including both the final version released in 2019 and a “clarification memo” issued in 2021, EPA recognized that costs and benefits must be weighed in deciding what measures are necessary to make “reasonable progress.” In similarly inconsistent fashion, earlier versions of the guidance suggested states must consider all sources for potential controls, while later versions recognize that states do not need to evaluate every source in every planning period.

Notably, EPA’s justification for rejecting the Kansas plan is not based on a determination that additional controls are needed on Kansas sources to make reasonable progress toward natural visibility conditions at any Class I area. Rather, EPA’s complaint is that the state did not evaluate any individual emission sources, but instead used other metrics to conclude that the potential benefits of additional controls would not be worth the cost.

According to EPA’s restatement of its guidance in the proposed disapproval, all states must review at least some individual sources under the so-called “four-factor” analysis, which Congress directed states to use in evaluating whether their SIP is sufficient to make “reasonable progress.” The Clean Air Act does not tell states how to consider those four factors, but, according to EPA, Kansas’s failure to march through them in evaluating individual sources was fatal to its SIP.

If EPA finalizes its disapproval as proposed and that action is challenged in court (both of which are likely), the lawsuit will go directly to the Tenth Circuit, which is the same court that heard the first regional haze case in round one. In that case, Oklahoma v. EPA, the state failed to convince two of the three judges that the state deserves deference instead of EPA, and that state determinations should not be overturned simply because they do not follow nonbinding guidance. Only time will tell whether the result will be different in round two, but so far, the pattern is too familiar to ignore.