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.