Three segments of the natural gas industry are involved in delivering natural gas from the wellhead to the consumer. Production companies explore, drill and extract natural gas from the ground. Transmission companies operate the pipelines that link the gas fields to major consuming areas. Distribution companies, like Columbia Gas of Virginia, are the local utilities that deliver natural gas to the customer.

Once natural gas is extracted from the ground and processed, it moves into the "transmission" system for long-distance travel. The gas is kept moving through these large, underground pipelines by a process called compression. "Pumping stations," located every 50 to 100 miles along the pipeline, increase pressure on the gas to move it along at about 15 miles per hour.

Transmission companies also operate storage fields for gas that's not needed right away - like in the summer - when the demand is down. These storage fields are actually underground rock formations that at one time held natural gas.

Once the gas in the transmission pipelines reaches a populated area, it runs into a "city gate," which is owned by the local gas distribution company. Here, the gas pressure is reduced and fed into smaller underground pipelines called "main" and "service" lines.

Main lines are larger and are usually found under main streets. They feed into smaller service lines that run at an even lower pressure. Service lines run under side streets and carry the gas to individual gas meters at homes, schools, offices and factories.

A 1-page download (77KB - PDF document), created by the American Gas Association provides a graphic depiction of how natural gas gets to consumers.