"It's a very important document both for regulators and the public," Nichols said. "As it operates and spews out pollution from its smokestack, we can be assured it is meeting all the requirements under the Clean Air Act."
Richard Mylott, a spokesman for the EPA in Denver, did not immediately comment but said the agency will review the lawsuit.
According to the group, the plant on the Uintah-Ouray Indian Reservation emits more than 3.5 million tons of pollution each year, including carbon dioxide, sulfur dioxide, nitrogen oxides, and other toxic compounds such as mercury.
It's a particular problem in the Uinta Basin, which already suffers from high ozone levels, Nichols said. Ground-level ozone can lead to asthma, scarred lungs and premature death.
"If we don't have the right checks, the right permits in place, we can't be assured public health is protected," Nichols said.
The lawsuit claims the EPA missed a mandatory October deadline to resolve a permit application filed by the plant's owner, Deseret Power, in 2012. It asks the court to order the EPA to issue or deny the permit within 30 days.
The group also claims that there is mounting evidence the plant is not operating in compliance with the Clean Air Act, and says it notified Deseret Power of violations in 2012.
Deseret Power, based in South Jordan, did not immediately return a call seeking comment Monday afternoon.
Deseret Power and federal regulators reached a settlement earlier this year in which the company was required to pay $35,000 in penalties, install new controls during startup and shutdown, and cover the cost of replacing at least five fleet vehicles with natural gas models.
Nichols said his group would like to see the terms of that settlement incorporated into the permit to be sure the company is following through.
Pursing a 'major polluter' permit
The nonprofit WildEarth Guardians sued the U.S. Environmental Protection Agency (EPA) Monday, arguing it is long overdue in issuing or denying an operating permit to the Bonanza power plant in northeastern Utah. The federal suit includes this timeline.
Permitting begins • In 1990, the Clean Air Act was amended to establish permits for major polluters, such as the power plant.
A dropped draft • In 2002, the EPA prepared and sought public comment on a draft permit for the plant but never took final action.
A new start • In February 2012, the EPA asked owner Deseret Power to submit a new permit application.
Application filed • On April 5, 2012, the EPA received Deseret's new application.
No action • An 18-month deadline required the EPA to act on or before October 5, 2013, the group contends. Instead, the EPA has neither issued or denied the permit for the 30-year-old plant, which has continued to operate.