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 McCarthy, 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.