A top official overseeing air quality is reportedly President Obama's preferred choice to take control of the Environmental Protection Agency (EPA).

According to Reuters, Gina McCarthyRegina (Gina) McCarthyOvernight Energy: Dems ask Pruitt to justify first-class travel | Obama EPA chief says reg rollback won't stand | Ex-adviser expects Trump to eventually rejoin Paris accord Overnight Regulation: Trump to take steps to ban bump stocks | Trump eases rules on insurance sold outside of ObamaCare | FCC to officially rescind net neutrality Thursday | Obama EPA chief: Reg rollback won't stand Obama EPA chief: Trump regulation rollbacks won't hold up legally MORE, the assistant administrator for the agency's Office of Air and Radiation, is the leading contender to replace outgoing EPA Administrator Lisa Jackson, who announced her plans to leave the agency in December.

The report cited two sources familiar with the matter in placing McCarthy at the top spot, but another source cautioned that no decision has been made yet. Bob Perciasepe, who works as Jackson's deputy, is another name reportedly in the mix to take over the environmental watchdog, and an announcement could still be weeks away.

Before joining the EPA, McCarthy served as a top environmental regulator in Massachusetts and Connecticut, and has served under governors from both major parties. She also served as an environmental policy adviser to Mitt Romney when he was governor of Massachusetts.

Whoever takes over the EPA would be taking the reins of an agency that is often caught in the partisan crossfire. Congressional Republicans mounted significant pressure on Jackson and the EPA during her tenure.

However, the next EPA head will also be in charge as Obama gears up to do more to tackle climate change. The issue was not a major priority in the president's first term, but he gave a spirited endorsement to efforts to fight the environmental changes in his second inaugural address, leading many to believe he will be mounting a new effort on that front.

"We will respond to the threat of climate change, knowing that the failure to do so would betray our children and future generations," he said. "Some may still deny the overwhelming judgment of science, but none can avoid the devastating impact of raging fires, and crippling drought, and more powerful storms."