An important component of this project is the addition of facilities that will allow the Transco pipeline to flow gas bi-directionally. The natural gas supply landscape has shifted as a result of new gas discoveries, particularly those located in the Northeast. As a result, pipelines like Transco are being modified so that gas that used to flow south-to-north can also flow north-to-south. In 2001, just 2 percent of U.S. natural gas production was from shale gas. By 2011, shale gas accounted for 34 percent of total US natural gas production. By 2020, that share will grow to 64 percent.