The Environmental Protection Agency announced studies this week showing that 15 power plants planned for Virginia would not harm air quality in Shenandoah National Park.

The finding contradicts allegations by the National Park Service that new coal- and oil-burning generators would have an adverse impact on air quality, visibility and plant life in the 195,000-acre park, which is about 60 miles from Washington. The U.S. Forest Service has argued that the plants would have a similar effect on the 8,900-acre James River Face Wilderness in western Virginia.

In March, the Virginia Air Pollution Control Board will begin considering whether to issue permits to several of the plants, including a 786-megawatt plant in Halifax County, said Beth Lester, a spokeswoman.

Officials from Virginia Power, which says the plants are needed to serve increased customer demand, hailed the EPA's finding. "We never felt these projects would have an adverse impact on the park," said spokesman Jim Norvelle.

Virginia Power has a total capacity -- including power bought from independently owned plants -- of 15,064 megawatts, and hopes to add nearly 5,000 more in the next decade, Norvelle said. The highest demand on record was 12,697 megawatts in December 1989.

Some National Park Service officials have questioned EPA's analysis.

EPA officials have acknowledged that parts of their study are too general, "not technically credible" and did not take into account days with particularly bad weather conditions. In a letter to state air pollution officials, the EPA also "reserved the opportunity to revisit these issues as additional analytic tools become available."

Environmentalists and park officials said they will continue to ask the state to require existing generators to reduce pollution emissions to compensate for the new facilities. The park, in the Blue Ridge Mountains, already suffers from acid rain and haze, which often obscure some of Skyline Drive's most famous views.

"When you have a system that is already adversely impacted . . . every increment will further degrade it," said Peter DeFur, a scientist with the Environmental Defense Fund's Richmond office.

If the state approves the new plants, the Park Service or an environmental group could appeal again to the EPA or file suit in federal court.

National Park Service spokesman George Berklacy said, "It appears the air has to be cleared between the EPA and the National Park Service. We would look to meet with them in the next few days."

The EPA may also get involved on another level. Virginia Secretary of Natural Resources Elizabeth H. Haskell wrote EPA Administrator William K. Reilly this month, asking him to organize a multistate effort to improve air quality.