President-elect Joseph R. Biden, Jr. has chosen Brenda Mallory, an environmental lawyer who spent more than 15 years working in the federal government under both Republican and Democratic presidents, to lead the Council on Environmental Quality, according to two people close to the Biden transition team.

The council is expected to expand its focus on issues of environmental justice under Ms. Mallory in addition to its traditional role of coordinating environment policy throughout the government, other people close to the presidential transition said.

Ms. Mallory, who currently serves as the director of regulatory policy at the Southern Environmental Law Center, a watchdog group, has worked on both pollution and land conservation issues throughout her career, including helping to create new national monuments under the Obama administration and fighting the dismantlement of those monuments under the Trump administration.