The latest attempt to block a federal rule addressing mercury pollution from power plants has failed.
The Mercury and Air Toxics Standards target mercury pollution from coal-fired power plants, which are the largest source of the toxin. Mercury can cause health problems, especially in children.
Last year, the Supreme Court sent the rule back to the lower courts after finding that the Environmental Protection Agency hadn’t adequately considered cost when formulating the rule. The agency has since done that.
But twenty states, including Wyoming and North Dakota, had asked the Supreme Court to overturn the lower court’s ruling that allowed the mercury standards to stay in effect while the EPA revised its analysis. The Supreme Court declined to take up that petition this week.
Coal plants can be retrofitted to filter out mercury emissions, but many power companies have chosen to shut down older plants instead of incurring the expense. It’s one of several factors that have contributed to the recent decline of the coal industry.