The United States maintains about 2 million miles of natural gas distribution mains and pipelines, 321,000 miles of gas transmission and gathering pipelines, 175,000 miles hazardous liquid pipeline, and 114 active liquid natural gas plants that are connected to natural gas transmission and distribution systems.2 A breakdown of pipeline mileage by state and type of pipeline can be found below.
The pipeline system includes:
- Gathering lines
- that collect and move products from sources such as wells on land or offshore to storage or processing.
- Transmission lines
- to transport large quantities of natural gas or hazardous liquids over long distances from gathering lines or storage facilities to distribution centers, storage facilities, power plants, industrial customers and municipalities. Petroleum transmission lines deliver crude oil to refineries and refined products to market. Most transmission pipelines are located underground.
- Distribution lines
- Main distribution lines move gas to industrial customers. Smaller distribution lines connect businesses and homes. Distribution lines usually are installed in underground utility easements along streets.
- Gas pipeline commodities
- include natural gas, hydrogen gas, propane gas and synthetic gas. Almost all gas gathering lines are for natural gas. Distribution and transmission are mostly for natural gas, but include some propane and hydrogen.