Supreme Court: Obama pollution rule invalid

The US Supreme Court on Monday invalidated a key Obama administration environmental regulation aimed at limiting emissions of mercury and other hazardous pollutants mainly from coal-fired power plants.

The court ruled in a 5-4 decision, with its five conservative justices in the majority, that the US Environmental Protection Agency (EPA) should have weighed the cost of compliance in deciding whether to regulate the pollutants.

The court sent the case back to the US court of appeals for the district of Columbia circuit, which will ask the EPA to reconsider its rule-making. In the meantime, the rule remains in effect, according to lawyers working on the case.

“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.

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.

Justice Antonin Scalia, writing on behalf of the court, said that a provision of the Clean Air Act that said the EPA can regulate power plants for mercury and other toxic pollutants if it deems it “appropriate and necessary” must be interpreted as including a consideration of costs. The EPA had decided it did not have to consider costs at that stage of the process.

“The agency must consider cost — including, most importantly, cost of compliance — before deciding whether regulation is appropriate and necessary,” Scalia wrote.

Industry groups and 21 states appealed after an appeals court upheld the regulation in June 2014. The challengers said the EPA’s refusal to consider the estimated $9.6 billion-a-year costs would lead to bigger electricity bills for Americans.