In a dissent, Justice Elena Kagan said that EPA had in fact considered cost throughout the rule-making process, just not at its initial "appropriate and necessary" finding that determined that EPA needed to act on mercury. She responded to Scalia's Ferrari analogy by saying that a more appropriate anaolgy is a car owner who replaces worn-out brake pads without considering cost.
"The comparison is witty but wholly inapt. To begin with, emissions limits are not a luxury good: They are a safety measure, designed to curtail the significant health and environmental harms caused by power plants spewing hazardous pollutants," Kagan wrote.
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"And more: EPA knows from past experience and expertise alike that it will have the opportunity to purchase that good in a cost-effective way. A better analogy might be to a car owner who decides without first checking prices that it is 'appropriate and necessary' to replace her worn-out brake-pads, aware from prior experience that she has ample time to comparison-shop and bring that purchase within her budget," Kagan added. "Faced with a serious hazard and an available remedy, EPA moved forward like that sensible car owner, with a promise that it would, and well-grounded confidence that it could, take costs into account down the line."
In a statement, EPA said it was disappointed with the ruling but touted the benefits that had already been felt from the rule and the plants that were already under compliance. The ruling, the agency added, was "not on the substance of the standards themselves."
"Since the decision was about how and when the agency considered costs in its decision that mercury and air toxic emissions from power plants threaten public health and the environment, and not EPA's Clean Air Act authority to limit hazardous air pollutants, EPA remains committed to ensuring that appropriate standards are in place to protect the public from the significant amount of toxic emissions from coal- and oil-fired electric utilities and continue reducing the toxic pollution from these facilities," said spokesman Melissa Harrison.
Industry groups and some Republican-led states charged that EPA had failed to consider the cost of compliance in writing the regulations. In oral arguments, the plaintiffs said that compliance could cost $9.6 billion a year because of the expensive technology required, costs that could lead to plant shutdowns and impact grid reliability.
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EPA has countered that the benefits would reach between $37 billion and $90 billion a year from health benefits that could save up to 11,000 lives. Further, EPA says the Clean Air Act does not require the agency to consider cost in setting its regulations.