LAS VEGAS — The National Park Service says a $3.8 billion coal-fired power plant is "unacceptable" because it would foul air and water and mar scenic views in the Great Basin National Park.

"Like a clean white page, the relatively clear air in the Great Basin can be marred easily," wrote Paul DePrey, park superintendent.

DePrey's letter earlier this month to the Nevada Division of Environmental Protection was in response to a draft air permit issued for the 1,500-megawatt Ely Energy Center. It is a project of Reno-based Sierra Pacific Power Co. and Las Vegas-based Nevada Power Co.

The division can issue a final permit without substantial changes in the draft document, amend the permit or deny it after reviewing comments.

"We agree with NDEP's initial filing that the Ely Energy Center meets all existing air quality standard regulations. This is all part of the NDEP environmental process, and we're not going to comment any further," said Adam Grant, a spokesman for the utilities.

Division spokesman Dante Pistone said his department does not give comments from federal agencies any more weight than from others.

"As a rule, we normally don't comment on the comments," Pistone said.

The state may take six months or more before deciding on the air-permit application, he said.

The Park Service letter says coal-fired plants in Utah appear to cause a brown-yellow haze after long periods of northeasterly winds.

"Fortunately, winds are seldom northeasterly for long periods," DePrey said. "If similar pollution sources were built to the west, the parks visibility would be affected more frequently. White Pine County's night skies are among the darkest in the country."

Air pollution would scatter light in the night sky and reduce visibility.

"Dark night skies, for the first time in history, are becoming an extinct phenomenon," he said.

Acid rain could affect life on land and in lakes in the Great Basin, he said.

Charles Benjamin, a spokesman for the Nevada Clean Energy Campaign, a group that opposes the power plant, supports those arguments.

The state agency, as the delegate of the Environmental Protection Agency, is legally charged with "preserving, protecting and enhancing national parks and wilderness areas," Benjamin said.

"The draft permit doesn't do enough to protect the park," he said.

Benjamin criticized the state division for failing to consider the combined air pollution from the 1,600-megawatt coal plant under development by LS Power Group and from the Ely project.

Some residents last week told the division they wanted the jobs that would come with the Ely power plant. Benjamin said the state may not consider job creation as a factor in approving an air permit.