The US supreme court struck down new rules for America’s biggest air polluters on Monday, dealing a blow to the Obama administration’s efforts to set limits on the amount of mercury, arsenic and other toxins coal-fired power plants can spew into the air, lakes and rivers.

The 5-4 decision was a major setback to the Environmental Protection Agency (EPA), and could leave the agency more vulnerable to legal challenges to its other new carbon pollution rules, from industries and Republican-led states.

The justices embraced the arguments from the industry and 21 Republican-led states that the EPA rules were prohibitively expensive and amounted to government overreach.



But the EPA pointed out that most plants had already either complied or made plans to comply with the ruling.

“EPA is disappointed that the court did not uphold the rule, but this rule was issued more than three years ago, investments have been made and most plants are already well on their way to compliance,” the agency said in a statement obtained by Reuters.

According to data compiled by SNL Energy, many generators in the US complied with the mercury and toxics compliance, despite the possibility that the court would strike down the rule.

The data showed that 200 plants, or roughly 20% of the US generating capacity, were given up to an extra year to comply with the standards, mostly in order to finish installing mercury controls.

Plants moved ahead with compliance plans due to the long lead time for environmental control projects, SNL said. The compliance deadline fell in April of this year.

The 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,” the agency added.

Monday’s decision, written by Justice Antonin Scalia, ruled that the EPA did not reasonably consider the cost factor when drafting the toxic air-pollution regulations.



The Clean Air Act had directed the EPA to create rules to regulate power plants for mercury and other toxic pollutants that were “appropriate and necessary”.

The agency had previously said it did not need to consider costs during that stage of the regulatory process. The agency estimated that the cost of its regulation to power plants would be $9.6bn a year, but it said that its analysis “played no role” in whether regulations were deemed “necessary and appropriate”.

The EPA also estimated that the rule would produce up to $37bn-$90bn in benefits and would prevent up to 11,000 premature deaths and 130,000 asthma cases each year.



The EPA rule took effect for some plants in April and was due to go into full effect by next year. In the meantime, the rule remains in effect, lawyers working on the case told Reuters. The ruling only concerns the cost consideration, so the EPA may try to write the rule again with cost in mind.



Scalia was joined in overturning the rule by the more conservative members of the bench, Chief Justice John Roberts, Clarence Thomas, Samuel Alito and Anthony Kennedy . The dissent, written by Elena Kagan, was supported by Ruth Bader Ginsburg, Stephen Breyer and Sonia Sotomayor.



In his majority opinion, Scalia called the EPA’s counterarguments “unpersuasive”.



In her dissent, Kagan said that the majority decision was “micromanaging” EPA’s rule-making, “based on little more than the word “appropriate”.



Kagan also said that the court’s invalidation of the EPA’s rule because the agency had not considered cost at the initial stage of the regulatory process was a “blinkered” assessment, considering the “subsequent times and ways EPA considered costs in deciding what any regulation would look like like”.







The landmark decision is the latest chapter in a two-decade-long effort to force stricter emissions standards for coal-fired power plants.

The regulation, adopted in 2012, would have affected about 600 coal-fired power plants across the country – many of which are concentrated in the midwest and the south.

It was already going into effect across the country. But Republican governors and power companies challenged the EPA’s authority, saying the agency had mishandled estimates of the cost of the new rules.

Monday’s decision was also a blow to years of local efforts to clean up dangerous air pollution.

The supreme court has now sent the case back to the Washington DC circuit court of appeals, which will ask the EPA to reconsider its rule-making. Activists are now urging the EPA to act definitively and quickly to issue revised regulation.

“The supreme court’s decision does not change the importance of EPA’s role in protecting our families and communities from toxic air pollution,” said Lisa Garcia of non-profit litigation group Earthjustice in a statement. “The court gave EPA the ability to finalize these critical public health protections once and for all. Now, EPA must act quickly. Thousands of lives are at stake.”

Political reaction was divided along party lines, in a week that has seen supreme court victories for liberals - on gay marriage - and conservatives - on the death penalty.

“Today’s supreme court decision represents a cutting rebuke to the administration’s callous attitude,” said Republican Senate majority leader Mitch McConnell. “The ruling serves as a critical reminder to every governor contemplating the administration’s demands to impose more regressive – and likely illegal – regulations that promise even more middle-class pain.”



Republican presidential candidate and Texas governor Rick Perry said Monday’s ruling “ends the false narrative that environmental protection can only be achieved through one-size-fits-all federal mandates and at the expense of economic growth.”



By contrast, Democratic senator Patrick Leahy, a ranking member of the Senate judiciary committee, said that there was nothing more “necessary and appropriate” than “curbing poisonous pollutants that the EPA estimates are responsible for thousands of early deaths, and tens of thousands more illnesses each year” and condemned the court for “letting corporate profits trump the public’s health”.



Democratic presidential candidate and former Maryland governor Martin O’Malley called the failure to limit poisonous toxins produced by power plants “a moral failure”. He said the court’s decision should reinforce “the need to transition to clean energy.”

The EPA and campaigners have argued that the public health costs posed by the toxic air pollutants outweighed those to utility companies forced to fit new control equipment.

Anna Aurilio, the Washington director of Environment America, said in a statement that the court’s decision “to let polluters off the hook is a huge setback for our kids’ health”.

Earthjustice said that the rules now invalidated by the court’s decision would have saved “between 4,000 and 11,000 lives each year by substantially reducing pollution from the dirtiest plants”.

In a statement, the group highlighted the fact that the court did not reject the key conclusions from the EPA, namely that power plants are “far and away the worst industrial polluters,” and controlling toxic emissions is “both technologically and economically feasible”.



Joseph O Minnott, chief counsel of the Clean Air Council, said his organization was “disappointed” by the court’s decision not to uphold the EPA rules, “which would bring many of the country’s oldest and dirtiest power plants in line with modern standards, and allow citizens to breath cleaner safer air”.



He added: “It is clear that the benefits to public health and the environment this rule would provide dwarf the costs of implementing it, no matter when in the determination those costs are considered.”

Michigan v EPA was the third recent test for the Obama administration’s environmental policies at the supreme court. In April 2014, the court endorsed the EPA’s efforts to deal with air pollution blowing across state lines in an important victory for Obama. In June 2014, the court largely upheld Obama’s plans to cut carbon pollution from power plants.