PRPA on fast track to remove mercury

By Dan MacArthur
North Forty News

The Platte River Power Authority has begun the costly process of reducing mercury emissions from its Rawhide Energy Station north of Wellington.

Monitoring already is underway to determine how much mercury is currently emitted so the utility can take steps toward meeting a state mandate to virtually eliminate that amount within a decade.

It will come at a price, however, that will be passed along to customers starting this year.

The Colorado Air Quality Control Commission required the state's power generators to begin monitoring stack emissions this month. But PRPA already was well ahead of the game, having installed its continuous stack monitor in September 2007, according to division manager John Bleem.

The mercury monitoring is the first step toward meeting the state mandate that power plants reduce mercury emissions by 80 percent by 2014 and 90 percent by 2018. The municipally owned PRPA, along with Minneapolis-based Xcel Energy, have volunteered to meet the first target two years early, however.

"We thought it was the right thing to do," Bleem said. "Our board looked at this and talked to the community. The feedback we got from the community was let's take care of this."

Colorado was one of the few states to impose its own standards after a federal appeals court rejected the Environmental Protection Agency's proposed national mercury control plan.

The appeals court ruled that the proposal failed to comply with the Clean Air Act by exempting power plants from state mandates. That ruling enabled states to implement their own standards until the Supreme Court decides whether it will hear the EPA's appeal.

Mercury is a heavy metal that can cause birth defects, nervous system disorders and brain damage. Dispersed primarily through the atmosphere, mercury deposited in lakes, rivers and reservoirs can accumulate in fish as well as the animals and humans eating them. Elevated levels of mercury found in fish from Horsetooth Reservoir, Carter Lake and Boyd Lake last year prompted a warning from the Colorado's Water Quality Control Division to limit consumption of fish caught there.

There is great debate and disagreement about the sources of mercury pollution and exactly how much they emit. Given that airborne mercury can travel long distances, some contend that mercury pollution is a global problem over which the United States by itself has little control.

The EPA estimates that 144 tons of mercury were deposited in the United States in 2005 with just over 11 tons of that produced by power plants within the country.

The remainder--93 percent--is believed to originate beyond U.S. borders. Much of that is presumed to be generated by China's coal-fired power plants.

The new monitoring requirement will for the first time determine exactly how much mercury Colorado power plants contribute to the total. Bleem said it took years to develop equipment capable of measuring the minuscule amounts of mercury Platte River emits.

He said monitoring to date has shown that its mercury levels are about half the amount originally estimated - or about 50 pounds a year. It is released from the 1.3 million tons of coal the utility burns annually mined from the Powder River Basin in Wyoming.

"It's a very small rate," Bleem said. "It will essentially be eliminated by 2018."

He equated the amount to filling a sports arena with a billion ping-pong balls, 30 of which would represent the concentration of mercury emitted.

Bleem said costs for meeting the new tougher mercury standards will be passed on to Fort Collins, Loveland, Longmont and Estes Park, which own the utility. Increases likely will be passed on to the cities starting next year and fully implemented in 2012.

The cities in turn will pass those costs on to customers. Rates this year already increased an average of 2.8 percent for Fort Collins electric customers, in part to cover the mercury mitigation measures.

The monitoring equipment will cost $500,000 plus $50,000 in annual operating expenses, according to Bleem. Additional equipment injecting powdered activated carbon into the stack to remove more mercury will cost $4 million plus $2.7 million in annual operating expenses, he said