President-elect Joe Biden has chosen Brenda Mallory, a longtime expert in environmental law and regulation, to head the White House’s Council on Environmental Quality, according to several people familiar with the decision who spoke anonymously because the appointment has not been publicly announced.

The nomination would place a veteran government official and conservation advocate in a key administration post, one who works closely with agencies to shape federal environmental and energy policy and to ensure individual communities have a voice in the construction of pipelines, roads and other potentially polluting projects.

Christy Goldfuss, who led the CEQ under President Barack Obama and worked closely alongside Mallory, said she was “ecstatic” about her nomination.

“She has the perfect personality and skill set to navigate these really difficult times,” said Goldfuss, now senior vice president for energy and environment policy at the Center for American Progress. “It really takes someone who knows how to collaborate and build consensus to get things accomplished. She is caring and thoughtful, but she also gets things done, and that’s a really rare combination at this level of politics.”

Mallory, if confirmed by the Senate, would be part of growing team of top administration officials who have long records of prioritizing climate and environmental issues.

Biden has tapped Gina McCarthy, who ran the Environmental Protection Agency under Obama and now leads a major advocacy group, to coordinate the new administration’s domestic climate agenda. He has named former secretary of state John F. Kerry as McCarthy’s counterpart, focusing on international climate policy. And he plans to nominate former Michigan governor Jennifer Granholm, a strong proponent for zero-emissions vehicles, as energy secretary.

Even Cabinet picks that traditionally don’t focus heavily on the environment — including Treasury Secretary nominee Janet Yellen, Transportation Secretary nominee Pete Buttigieg and National Economic Council director Brian Deese — have called for the government to prioritize lowering the nation’s emissions.

Mallory, 64, a graduate of Yale University and Columbia Law School, has spent decades working on environmental issues both inside and outside of government, and that experience is a major reason Biden chose her for the role — along with the fact that she would represent a historic choice as the first African American to head the office, said those familiar with his thinking.

“She is committed to advancing environmental justice, which is why the president sees her as uniquely qualified to run CEQ,” said one of those people.

Mallory’s path was one she fell into partially by accident.

“I stumbled into it,” she said in an announcement of her most recent job, as director of regulatory policy for the Southern Environmental Law Center, which has challenged the rollback of numerous environmental safeguards under the Trump administration. “I joined a D.C. firm to support the growth of its commercial litigation practice and the firm was an environmental boutique. Soon, I was developing expertise in environmental law and the rest is history.”

That early decision put her on a path to becoming one of Biden’s top environmental advisers — and leading the office she already worked at once before.

Mallory served as general counsel for the CEQ under Obama, supporting the administration’s efforts to bolster clean energy, combat climate change and expand the nation’s public lands.

“I worked on 22 of 35 national monuments he designated under the Antiquities Act. Each was spectacular in its own way, revealing the history, ecology, and spirit of special places,” Mallory said in an SELC online biography. “It was great learning about each area and being part of historic designations.”

Before taking that White House role, Mallory spent years as a top legal official at the Environmental Protection Agency.

“Particularly on environmental justice, Brenda offers the White House experience and insight that had been missing from the appointments to date,” Kevin Minoli, a partner at the law firm Alston & Bird who worked with Mallory during his nearly two decades as an EPA career attorney, said in an email. He said he expects her to play a critical role in “ensuring that among the things the federal government considers when designing a new project or regulation is the potential for government action to have disparate impacts on communities of color and low income communities.”

After leaving the federal government at the end of Obama’s presidency, Mallory worked as executive director and senior counsel at the Conservation Litigation Project, which pushed for policies to protect public lands.

“President Biden is going to be taking over at a time where there’s just unprecedented destruction at agencies like the Environmental Protection Agency,” Mallory said in a video posted on SELC’s website just after the November election. “I spent 17 years in the federal government, working for both Republican and Democratic administrations. And I can tell you, what we’re seeing under the Trump administration is very different than what we have seen in the past.”

But Mallory also has underscored that reversing the Trump administration’s assault on existing regulations won’t happen overnight.

“You can’t just walk in on day one and roll back the rollbacks,” she said in the same video. “Undoing the actions of an administration take time, and they take a lot of effort.”