President-elect Trump's threats of rolling back President Obama's environmental regulations are more "rhetoric" than reality, according to Gina McCarthy, the outgoing head of the Environmental Protection Agency.

"I've certainly heard all of this," EPA Administrator McCarthy said in a Wednesday interview with the Washington Post.

Although she is "concerned, without question" about Trump being sworn in, much of what she heard coming from Trump "I'd call political rhetoric."

McCarthy said she feels "pretty confident that what we have done is really very solid work," and will stand up to critics that say the agency overstepped its authority.

In some cases, some of the regulations that Trump has targeted for repeal have already gone into effect years ago and industry has already complied. For instance, major utility regulations for controlling air pollution and mercury from coal- and oil-fired power plants, are "already done, [companies] are already complying," she said. "We're so past that."

The utility industry said the rules cost $9 billion annually to comply with, but the investments made in order to meet the air pollution and mercury standards have already been made.

As for many of her agency's other contentious regulations, such as the Clean Power Plan, which is the centerpiece of President Obama's broad climate change agenda, McCarthy believes the regulations will stand against the coming Trump onslaught of deregulation. The president-elect said repealing the plan is part of his first 100-day agenda, along with other regulations harming the coal industry.

"There was a long, very large body of work we had to get through" to construct the regulations, McCarthy explained. "As far as I know, we've done it extraordinarily well. So it's not like a blink of an eye and all that goes away," she said.

The Clean Power Plan directs states to cut a third of their greenhouse gas emissions. Nearly 30 states, over half the country, are opposing the EPA plan in federal appeals court.

An unprecedented 10-judge panel is currently review the states' arguments that say the plan oversteps EPA's authority and violates the Constitution. The climate rules were halted by the Supreme Court in February while the federal appeals court reviews the arguments against it.