US Supreme Court rejects mercury emissions regulation

The US Supreme Court today rejected an environmental regulation limiting the amount of mercury emissions and other pollutants that power plants can pump into the atmosphere.
In a 5-4 decision split along conservative and liberal lines, America's top court sided with 21 states and industry groups protesting standards imposed in 2012 that require power plants to cut toxic emissions.
The standards had been imposed by the national Environmental Protection Agency (EPA).
On the last day of its annual session, the Supreme Court said the EPA had "interpreted unreasonably when it deemed cost irrelevant to the decision to regulate power plants."

The plaintiffs in the case had complained about the "huge costs" required to comply to the standards.
The standards were adopted in 2012 and were to have taken effect this year, requiring coal or oil-burning plants to drastically reduce their mercury emissions.

The pollutant is considered especially toxic to children and pregnant women.
The Supreme Court ruling is a blow to the Obama administration and comes on the heels of two historic rulings last week that supported progressive causes -- legalizing gay marriage across America and upholding President Barack Obama's health care overhaul.
Republicans, who spent recent days blasting the Supreme Court over the decisions, were relatively muted after the mercury ruling.

"#SCOTUS took an important step to help ensure the EPA takes into account the true cost of excessive regulations on the American people," Republican Senator Steve Daines of Montana wrote on Twitter, using the acronym for the Supreme Court of the United States.
The challengers of the regulation included 21 states led by Michigan, a coalition of power plants and the US National Mining Association.