At the close of 2004, the U.S. natural gas transportation network included more than 200 mainline natural gas pipeline systems. Combined, these 107 interstate systems and more than 90 non-interstate systems account for over 297,000 miles of pipeline.

Moreover, the interstate network represents approximately 148 Bcf/d of natural gas transportation capacity while the non-interstate pipelines account for at least 30 Bcf/d. During 2004, total U.S. natural gas pipeline system mileage increased by less than 1 percent while overall system capacity increased by slightly more than 4 percent.

Expansion of the U.S. natural gas transmission network slowed in 2004, both in terms of added transportation capacity and new pipeline mileage. Only about 1,450 miles of pipeline and 7.7 Bcf/d of natural gas pipeline capacity were added to the national gas transmission grid during 2004, compared with 2,243 miles and 10.4 Bcf/d of capacity in 2003. The amount of incremental capacity in 2004 was the least since 1999 when only 6.5 Bcf/d was added.

During 2004, six new pipeline systems were placed in operation in the deepwater Gulf of Mexico, plus the 560-MMcf/d Cheyenne Plains Pipeline, and a 320-MMcf/d expansion of the southern leg of the El Paso Natural Gas pipeline system.

In the past few years, several major natural gas pipelines came online: the Gulfstream Pipeline, 1,130 MMcf/d-560 miles, which carries natural gas under the Gulf of Mexico from gas-processing facilities located on the Gulf coasts of the States of Mississippi and Alabama to west central Florida; the North Baja Pipeline, 500 MMcf/d-80 miles (in the U.S.), which exports gas to electric power plants located in Baja California, Mexico; the Questar Southern Trails Pipeline, 87 MMcf/d-405 miles, which transports gas from the four corners area of New Mexico/Utah (San Juan Basin) to the California/Arizona border area; and the Guardian, 750 MMcf/d-142 miles, and Horizon, 380 MMcf/d-29 miles, pipelines, which expanded the flow of gas supplies between the Chicago hub and the growing market of northern Illinois and southern Wisconsin. On December 1, 2000, the $2.9 billion, 1.3-Bcf/day Alliance Pipeline from western Canada (Fort St. John, British Columbia) to the Chicago area entered service.

Source: Energy Information Administration