房山区
Construction of the Yanfang Line was scheduled to commence in September 2011 and be completed by 2013. On October 17, 2011, the Ministry of Environmental Protection declined to approve plans for the line citing lack of approval for the project from the National Development and Reform Commission and uncertain environmental impact of the line on the South–North Water Transfer Project which has a channel and reservoir in Fangshan District. As a result, the onset of construction was delayed to at least the end of 2013.