Mike Whitfield, director of Public Works for Falls Church, will be leaving his post this month to accept a position in the private sector on the West Coast next month, it was reported Tuesday. His tenure in F.C. will end June 19, City Manager Wyatt Shields said, and while there is a hiring freeze for the coming year in the City, an interim replacement will be found in this case and Shields said it will likely come from within the department.