The Platte River Power Authority has spent $1.5 million in its latest effort to lower nitrogen oxide emissions from its coal-fired Rawhide Energy Station.

The move, completed last month, should reduce nitrogen oxides emissions by about 30 percent, said John Bleem, Platte River Power Authority customer and environmental services division manager.

Platte River spent a total of $11.5 million as it shut down its facilities to perform maintenance and replace parts and machinery while making the upgrade.

The investment helps Rawhide maintain its status as among the nation's cleaner power plants, though environmentalists say it could do more.

They say that recent improvements by Rawhide to reduce its nitrogen oxides do little to reduce climate-altering carbon dioxide emissions.

"We need to move away from reliance on coal and shift towards reliance on cleaner energy sources," said Gwen Farnsworth, senior energy policy advisor for Boulder-based environmental group Western Resource Advocates.

Rawhide emits less sulfur dioxide and nitrogen oxides on average compared with other plants throughout the United States, according to Platte River.

Citing Environmental Protection