The Supreme Court heard oral arguments on Tuesday over how to regulate power plant air pollution that crosses state borders in a complex case that, with one justice recusing himself, could be headed toward a tied decision between the bench's liberal and conservative wings.
During the 90 minutes set aside for the case, instead of the usual hour, the justices were troubled over how to best deal with the fines and regulations aimed at states under the Environmental Protection Agency's (EPA) cross-state air pollution rule.
The EPA rule, which was struck down last year by the U.S. Court of Appeals for the D.C. Circuit, requires 28 states to cut back on emissions from coal-fired power plants that "contribute significantly" to the air problems in other states.
Solicitor General Jonathan Mitchell, arguing on behalf of certain upwind states, said the EPA "left the states completely in the dark about their good-neighbor obligations."
He added that until the agency fills in the blank on what "contribute significantly" means, it cannot adequately regulate or enforce the rule, leaving states to guess.
Justice Stephen Breyer disagreed.
"It all depends on where the wind blows," Breyer said. "They cannot tell you how much to cut back because you’re asking them to do the impossible."
Justice Antonin Scalia said while a cost-based regulation may be a wise policy "it's certainly not the statute that Congress wrote."
Justice Samuel Alito Jr. disqualified himself on Tuesday, leaving open the possibility of a 4-4 tie on the bench, which would leave the D.C. Circuit ruling in place.
In its brief, the EPA explained the complexity of its chosen model.
"The interstate pollution problem is thus best understood as a dense, spaghetti-like matrix of overlapping upwind/downwind ‘linkages’ among many States, rather than a neater and more limited set of linkages among just a few, prohibiting emissions that ‘contribute significantly’ to air pollution problems in other States until after the EPA has adopted a rule quantifying each State’s inter state pollution obligation," the brief said.
The EPA also cited a study in its brief that found "one in 20 deaths in the U.S., 200,000 non-fatal heart attacks and 90,000 hospital admissions" a year are a result of ozone exposure and fine particle emissions.
If the Supreme Court does reverse the lower court's ruling it would establish one of the two EPA regulations that came before federal courts on Tuesday -- both serve as pillars of the Obama administration's second-term climate change agenda.
The D.C. Circuit also heard arguments on Tuesday over an EPA rule that limits the amount of mercury, arsenic and other substances that can be spewed into the air from power plants.