The FAA has sent a strong message to Contra Costa County: Buchanan Field must remain open. The FAA said in a recent letter that the California airport serves as an important reliever airport and is a base for more than 580 aircraft. Also, because the federal government deeded the land to the county and the county has accepted federal funding, it is obligated to keep the airport open in perpetuity. A county supervisor wants to relocate the airport so that the land can be used for housing or retail development. Members of Congress have pressed the FAA to take a strong stand against closure.