The timing of Lisa Jackson’s departure from EPA has been clarified from “after the State of the Union speech” to a firm date of February 14. Deputy Administrator Bob Perciasepe will step into the EPA Administrator role on an interim basis at that time. A permanent successor to Jackson has not been nominated, though speculation seems to be solidifying around a group of three potential candidates: Perciasepe, EPA Assistant Administrator for Air and Radiation Gina McCarthy and former Washington Governor Christine Gregoire. An official nomination to head the agency is expected in the next several weeks.