Coal interests and Republican politicians in Kentucky cheered Monday's ruling by the U.S. Supreme Court that federal environmental regulators failed to properly consider the costs of complying with a rule to cut mercury and other pollutants from power plants.
Environmentalists, however, decried the decision as a setback for public health.
The decision has particular resonance in Kentucky because it is a significant coal-producing state and gets nearly all its electricity from burning coal at power plants, which also makes it a leader in airborne mercury emissions.
The mercury rule has played a role in decisions by utilities to shutter older coal-fired plants, though there have been many other factors in that as well, including the price of natural gas and expected rules limiting carbon-dioxide emissions.
Those plant closures have been a factor in a sharp downturn in coal production in Eastern Kentucky.
Bill Bissett, president of the Kentucky Coal Association, said Monday's decision could mean a longer lifespan for some coal-fired power plants.
"We have told electric utilities and the public that many of the Obama Administration's anti-coal policies would not pass legal scrutiny, and it is good to see this prediction hold true" on the mercury rule, Bissett said. "Today's U.S. Supreme Court ruling is good news for coal-mining, coal-using states like Kentucky."
The ruling alone won't mean a resurgence of the Eastern Kentucky coal industry, however.
The Supreme Court sent the U.S. Environmental Protection Agency rule back to a lower court for further consideration.
That means it will stay in effect until an order from that lower court, according to Tammy Ridout, a spokeswoman for American Electric Power, which has 171,000 customers in Eastern Kentucky.
And the coal industry in Eastern Kentucky faces challenges unrelated to the mercury rule, including cheap natural gas, cheaper coal from elsewhere and relatively high production costs.
Still, Ridout said AEP was pleased the Supreme Court recognized that compliance costs are "an important component of rational agency decision-making."
"The case underscores that the Supreme Court expects the EPA to implement the Clean Air Act as written, not according to its own policy preferences," Ridout said.
U.S. Sen. Mitch McConnell and U.S. Rep. Hal Rogers, both Republicans, said the ruling was a sharp rebuke to EPA over-reach.
"The justices clearly directed this agency to examine the impact of its rule-making policies on our utilities before setting unrealistic limits," Rogers said.
McConnell said in a statement that Obama Administration officials "like to pretend that the costs of their massive and regressive regulations either don't exist or don't matter."
"Middle-class families in Kentucky and across our country don't have that luxury, and are often the first to suffer," McConnell said.
But there's a terrible consequence to not limiting emissions of mercury and other toxic emissions, said Deborah Payne, health coordinator for the Kentucky Environmental Foundation.
There is an advisory in place for waterways across Kentucky against eating too much fish because of mercury contamination, Payne said.
Pregnant woman are a particular concern because mercury can damage developing babies in the womb, according to the EPA.
Payne noted that Justice Elena Kagan said in her dissent to Monday's ruling that EPA estimated the benefits of the rule — including 11,000 fewer premature deaths nationally a year — would far exceed the costs.
"What's frightening is this is a big step back for air-quality standards," Payne said of the majority decision. "Coal based air pollution is one of Kentucky's biggest environmental health concerns."