WASHINGTON — The Supreme Court ruled Monday against the Obama administration’s requirement to limit power plant emissions of mercury and other hazardous air pollutants — but it may only be a temporary setback for regulators.
The justices split 5-4 along ideological lines to rule that the Environmental Protection Agency failed to take cost into account when it first decided to regulate the toxic emissions from coal- and oil-fired plants.
The EPA did factor in costs later, when it wrote standards that are expected to reduce the toxic emissions by 90 percent. The court said that was too late.
The rules, which took effect in April, will remain in place while the case goes back to a lower court for the EPA to decide how to account for costs, environmental advocates say.
Colorado in 2008 implemented its own rule to curb mercury — a toxic element that can build up in the environment and cause neurological damage and birth defects in humans.
The Colorado rule required all coal-fired power plants to capture 80 percent of mercury emissions in 2014, rising to 90 percent by 2017.
The state’s three major coal-burning utilities — Xcel Energy, Tri-State Generation and Transmission Association, and the Platte River Valley Power Authority — have all added mercury-pollution controls, according to the companies.
“The impact of the court ruling in Colorado will be very limited,” said Will Allison, director the state’s Air Pollution Control Division.
The EPA said it is reviewing the court’s decision and will determine any appropriate next steps.
