A revised mountaintop removal permit that federal regulators touted as less damaging actually leaves larger areas unreclaimed for longer periods of time, an international mining expert testified Friday in federal court.

John Morgan, a mining engineer hired by environmentalists, said that the new Arch Coal Inc. permit was given a variance from the federal law's "contemporaneous reclamation" requirement.

The company's permit application, however, does not include a required explanation of why the mine couldn't comply with the requirement and needed a variance, Morgan told Chief U.S. District Judge Charles Haden II.

"It does not contain adequate detail," Morgan said. "There is no engineering data."

Morgan testified for two hours Friday morning in the second day of a hearing on the West Virginia Highlands Conservancy's request for a preliminary injunction against the mine.

Arch Coal subsidiary Hobet Mining Inc. wants a permit to strip 3,100 acres along Pigeonroost Branch near Blair, Logan County. Environmentalists want to stop the mine.

The Pigeonroost permit, covering nearly 5 square miles, is the largest mountaintop removal proposal in West Virginia history.

On Wednesday, Haden issued a 10-day temporary restraining order to halt the operation while he hears testimony and legal arguments about alleged problems with the permit.

The U.S. Justice Department exempted the Pigeonroost permit from a new, stricter policy on mountaintop removal permits. The agency said that Hobet Mining had agreed to reduce the size of valley fills and mitigate adverse environmental impacts of the mine.

Morgan testified Friday that under the revised permit, three of the mine's nine phases will involve more than 1,500 acres being disturbed at one time. The original permit did not involve any phases with that much disturbed area, Morgan said.

"Disturbed areas are what sometimes cause environmental problems like dust and runoff during mining," Morgan said. "The greater the amount of total area that is disturbed, the greater the problems like runoff will be."

John Morgan, a mining engineer hired by environmentalists, said that the new Arch Coal Inc. permit was given a variance from the federal law's "contemporaneous reclamation" requirement.

The company's permit application, however, does not include a required explanation of why the mine couldn't comply with the requirement and needed a variance, Morgan told Chief U.S. District Judge Charles Haden II.

"It does not contain adequate detail," Morgan said. "There is no engineering data."

Morgan testified for two hours Friday morning in the second day of a hearing on the West Virginia Highlands Conservancy's request for a preliminary injunction against the mine.

Arch Coal subsidiary Hobet Mining Inc. wants a permit to strip 3,100 acres along Pigeonroost Branch near Blair, Logan County. Environmentalists want to stop the mine.

The Pigeonroost permit, covering nearly 5 square miles, is the largest mountaintop removal proposal in West Virginia history.

On Wednesday, Haden issued a 10-day temporary restraining order to halt the operation while he hears testimony and legal arguments about alleged problems with the permit.

The U.S. Justice Department exempted the Pigeonroost permit from a new, stricter policy on mountaintop removal permits. The agency said that Hobet Mining had agreed to reduce the size of valley fills and mitigate adverse environmental impacts of the mine.

Morgan testified Friday that under the revised permit, three of the mine's nine phases will involve more than 1,500 acres being disturbed at one time. The original permit did not involve any phases with that much disturbed area, Morgan said.

"Disturbed areas are what sometimes cause environmental problems like dust and runoff during mining," Morgan said. "The greater the amount of total area that is disturbed, the greater the problems like runoff will be."

Under cross-examination by Hobet Mining lawyer Bob McLusky, Morgan testified he wasn't saying the revised permit would definitely have greater adverse environmental effects.

But he said, "The disturbed area under the revised permit is greater than that proposed by the original permit. You may have additional runoff, additional sedimentation, and greater potential for more dust."

In response to questions from McLusky, Morgan also said that mountaintop removal mines that he helped plan dumped leftover rock and earth in streams.

Morgan also testified that he did not believe the approximate original contour reclamation rule applies to valley fill areas of mining sites.

"Yes, we flat-topped the valley fills," he said.

Also Friday, Haden said he would postpone a visit to a mountaintop removal site and a flight over mountaintop removal mines in Southern West Virginia.

The tour was originally scheduled for Tuesday. But Haden said he wanted to hear more evidence on Tuesday and Wednesday, then decide when to reschedule the tour.

In a related matter Friday, the U.S. Office of Surface Mining said it has again extended the public comment period on its report on mountaintop removal.

OSM Director Kathy Karpan said the comment period, set to close Friday, will be extended another week, through Feb. 12. Karpan said she received requests from coalfield citizens and others asking for additional time. The report, released in draft form in December, was supposed to be finished in mid-August.