Andrew Wheeler, acting administrator of the Environmental Protection Agency, has a lot of work ahead of him to complete the deregulatory agenda that his recently departed predecessor, Scott Pruitt, started.

Wheeler says he's ready to make a lasting impact, whether or not he is confirmed as EPA's permanent leader.

"Of course we are absolutely implementing Presidents Trump's agenda," Wheeler told the Washington Examiner in an interview at EPA headquarters on his third day in the top job. "We can protect the air, we can protect the water, and still deregulate at the same time. I don’t expect to change everything in the brief tenure that I will have here, but I hope to put the agency on the glide path to looking at things differently."

Conservative legal and environmental experts say Wheeler, EPA's No. 2 official until Pruitt resigned this month due to various ethics scandals, could serve as a more disciplined, understated, professional — and effective — leader of EPA.

If true, that would help the agency overcome critics who say the EPA under Pruitt had little to show for his campaign to rewrite rules combating climate change, and little hard evidence of its necessity.

“On the regulatory front, they haven't accomplished nearly as much as they could have by this point,” said Jeff Holmstead, a former deputy administrator of the EPA in the George W. Bush administration. “They did a good job of getting started on these issues, but even a lot of Pruitt supporters would say Andy may be the right person to do all the hard regulatory work still in front of the agency. This is the role Andy has always looked forward to having, and I think he is going to be able to get an awful lot done in the next few years.”

Wheeler is a career conservative Senate staffer, lawyer, and lobbyist with EPA experience and bipartisan relationships, whereas Pruitt was a former attorney general of Oklahoma who had sued the EPA multiple times and had ambitious political goals.

“This sounds like a criticism of Pruitt,” Holmstead said. “He was not very sophisticated about the realities of the regulatory process and the realities of doing things that are legally defensible and durable. Andy won't waste his time taking on issues just to satisfy a particular constituency. He will want to do things that are sensible and lead to meaningful long-term reforms.”

For supporters eager to restrain President Obama’s environmental agenda, time is running short.

So far, the Trump administration has targeted at least 45 environmental rules, including 25 at the EPA, according to a rollback tracker by Harvard Law School’s energy and environment program.

These actions would delay, weaken or repeal various regulations on air, water and climate change, and transform how the EPA uses science to make its regulatory decisions.

But at least six of Pruitt’s actions have been overturned by the courts, according to the New York Times.

“A lot of the things Pruitt proposed and Andrew will presumably continue are defective not because Pruitt failed to do his homework, but because the proposals themselves are very hard to justify,” said Joe Goffman, executive director of the Harvard Environmental and Energy Law Program, who was the lead attorney at the EPA during the Obama administration.

The EPA has also yet to propose replacements for three of the biggest Obama-era regulations that President Trump has vowed to target, although the agency is expected to act this summer.

They are rules affecting carbon dioxide emissions from coal power plants, the fuel efficiency of cars, and the agency’s control over waterways.

These proposed rules would still have to face a lengthy public comment period, and then be finalized.

“We are now looking at not getting these rules repealed and replaced by end of first Trump’s first term,” said Myron Ebell, director of the Center for Energy and Environment at the free-market Competitive Enterprise Institute, who led the EPA’s transition team for Trump. “If they don't get it done in the first term and there isn't a second Trump term, they can be repealed again and put back the way they were under Obama.”

Wheeler says he's not worried about pace, and he won't neglect the process.

"Part of my background having worked here at the agency, having worked on the Hill, I have seen the change in administrations," Wheeler said. "I have seen the change in priorities and change in regulatory approaches. So I understand what we do needs to be lasting and we need to make sure we get it right. So I am going to be very cognizant in our rule-makings that we follow the law and that our regulations can stand up to legal challenges. Because the American people need that certainty."

Below is a status update on the three most high-profile aspects of the EPA’s deregulatory agenda, what’s left for Wheeler to do, and how his approach to the issues may differ from Pruitt’s.

1. Weakening the Clean Power Plan

The EPA is in the process of repealing and replacing the Clean Power Plan, Obama’s signature initiative to combat climate change, with a narrower rule more friendly to industry.

"President Trump made it very clear on the campaign that he wanted to repeal the Clean Power Plan, repeal WOTUS (more on that below) and replace them with something that actually followed the letter of the law, and we are working to do that," Wheeler said.

The 2015 Clean Power Plan, which was never implemented because of a Supreme Court stay, required states to reduce carbon dioxide emissions 32 percent below 2005 levels by 2030, by shifting away from coal plants.

The Trump administration says Obama based the Clean Power Plan on an expansive and illegal interpretation of the Clean Air Act.

Under the rule, the EPA gave each state a goal for reducing emissions and encouraged broad ways to meet those targets, such as moving away from coal to natural gas, and transitioning to wind and solar power.

Earlier this month, the EPA sent the new rule to the White House for review.

"What we are are trying to do is make sure the replacement follows the Clean Air Act," Wheeler said. "I am sure we will be criticized by some members of Congress who would prefer us to go further and some environmental groups who would prefer us to go further. But frankly, we don't have that authority under the Clean Air Act to do what everybody would like us to do."

Although Wheeler would not release details, experts expect the rewritten rule to regulate power plants on a plant-by-plant basis, and give more discretion to states. For example, the EPA could mandate heat rate improvements in power plants, which would burn coal more efficiently by creating more electricity per unit of coal.

“I am sure they will be looking at things that can be done at a plant to reduce its CO2 emissions rate,” Holmstead said. “That has been done for other pollutants under the Clean Air Act and is more legally defensible.”

2. Working with California on fuel-efficiency rules

The EPA is working with the Transportation Department to weaken strict fuel-efficiency rules established by Obama, recently submitting a proposal to the White House.

Automakers had urged Trump to ease Obama’s standards, arguing they are too tough to meet with drivers favoring bigger, less fuel-efficient cars as gasoline prices have fallen. But now they worry his administration is going too far.

The Trump administration, with Pruitt leading EPA, was considering a proposal to freeze fuel-efficiency and greenhouse gas emissions targets at 2020 levels through 2025.

The EPA also is weighing challenging California over a waiver it has under the Clean Air Act that allows it to set its own, stricter air pollution rules. California is leading a coalition of states suing the Trump administration for rejecting the Obama standards.

Wheeler said he is committed to reaching a compromise with California to maintain a single national program, with all states using the same standards.

That would appease automakers, who fear facing a patchwork of regulations preventing them from selling the same cars in every state.

"I am happy to work with California on this," Wheeler said. "We really want a 50-state solution. We don't want to go to court over this."

3. Shrinking the Waters of the U.S. rule

The EPA is aiming to shrink Obama’s Waters of the U.S. rule, commonly referred to as WOTUS.

WOTUS expanded the EPA's jurisdiction over waterways by broadening the definition of "navigable waters" protected under the Clean Water Act to include drainage ditches and livestock watering holes. Farmers, ranchers, and developers said the rule violated their property rights, forcing them to protect the streams and tributaries that flow through their land.

Pruitt initially tried to repeal the rule with a skimpy, 11-page proposal, but late last month, the EPA produced additional documents. Several states, led by New York, have sued the EPA for delaying implementation of Obama’s WOTUS rule.

“The original proposal just wasn’t meaty enough to satisfy the legal obligations,” Holmstead said. “They will come up with a much more robust proposal.”

EPA sent its draft replacement rule to the White House for review last month.

Under the proposal, the EPA and the Army Corps would enforce the water regulations under the older, limited definition of waterways, which included primarily large bodies of water like rivers.

"This fight will go to the Supreme Court," Goffman said.