The owners of nearly two dozen coal-burning power plants, including Topeka-based Westar Energy, could face lawsuits from the Environmental Protection Agency for clean air violations stemming from plant expansions or improvements, according to agency officials and documents.

The EPA and the Justice Department are considering actions against operators of 22 plants for alleged violations of a regulation that the Bush administration has been trying to scale back and make less burdensome to the industry.

The rule requires utilities to install additional pollution controls when making expansions or improvements that result in more emissions. Utilities have argued the rule has been abused by regulators targeting routine, needed maintenance.

No decision on whether to file the lawsuits has been made but at least 14 of the cases have been turned over to the Justice Department for possible action, said an EPA official, speaking on condition of anonymity because the cases are pending.

The case involving Westar Energy has not been turned over to the Justice Department, according to the EPA official.

Karla Olsen, a spokeswoman for Westar, said the company was notified in January by the EPA that the company’s Jeffrey Energy Center which is north of Topeka was under investigation for violating the clean air requirement.

Olsen said the company was involved in ongoing discussions with the EPA.

“We believe we have been in compliance with the EPA regulations,” Olsen said.

Westar also operates the Lawrence Energy Center, a coal-fired power plant northwest of the city. She said the company had not been notified of violations at that plant.

Some cases may be settled before going to court or possibly dropped, the EPA official and industry sources said.

The enforcement agenda represents five years of preparation by EPA staff to identify alleged clean air violations under the so-called “new source review” requirements of the Clean Air Act. Among the targets are some of the country’s largest utilities.

The enforcement cases involve regulations that have been strongly criticized by the White House and have been the target of an intensive overhaul within the EPA because of arguments by industry that they have hindered plant maintenance, expansion and efficiency.

In December, a federal appeals court blocked the Bush administration’s planned changes in the “new source review” rules until a lawsuit filed by more than a dozen states challenging the changes can be fully considered.

In the meantime, EPA Administrator Mike Leavitt has said he favored vigorously prosecuting violators of the rules, including cases filed by the Clinton administration as well as any new cases that have merit.

Scott Segal, a spokesman for the Electric Reliability Coordinating Council, a utility group, said a decision to pursue these new cases “creates more uncertainty” and would further prompt utilities to put off needed maintenance and efficiency improvements for fear of lawsuits.

But environmentalists have criticized the EPA for not adequately enforcing the regulations, which they argue would significantly reduce smokestack emissions if aggressively enforced.

“We have 150 million people exposed to unhealthy air in the country. Yet these utilities are being allowed to circumvent their clean air obligations,” said William Becker, executive director of two associations that represent state and local air pollution control officials.