Moving gas: pipelines, storage and LNG

A gas power plant can be 1,000 miles from the nearest well. Everything in between is pipe, pressure and paperwork, and each piece has a different regulator. Learn the map and one phone call tells you whether a complaint belongs at FERC, at PHMSA or at the state utility commission. Skip it and you can spend a month writing to the wrong agency.

EIA counts roughly 3 million miles of gas pipeline of all kinds in the US. About 217,000 miles are interstate transmission mainline. PHMSA's 2025 data show about 1.39 million miles of distribution main and an estimated 1 million more miles of service lines to some 73 million customer connections. The big lines are the minority. The small ones run under every street with gas service.

The chain, from wellhead to burner

Gathering lines

Small-diameter, lower-pressure pipes carry raw gas from individual wells to a processing plant or a larger line. They have historically been the least regulated part of the system. Many rural gathering lines were exempt from most federal safety rules until PHMSA's 2021 gas gathering rule began extending reporting and some standards to them. If a gathering line runs near homes in your area, ask the state oil and gas agency who inspects it.

Processing plants

Raw gas from the well is wet: it carries water, natural gas liquids and sometimes hydrogen sulfide. Processing plants remove those so the gas meets pipeline quality. The liquids (ethane, propane, butane) are sold separately. These plants need air permits for their engines, flares and heaters.

Transmission lines and compressor stations

Interstate transmission lines are typically 20 to 42 inches across and run at high pressure, commonly several hundred to well over 1,000 pounds per square inch. Friction steadily bleeds pressure, so compressor stations sit along the line, often roughly every 40 to 100 miles depending on terrain and design. Each station uses gas-fired turbines or reciprocating engines (sometimes electric motors) to push the gas back up to pressure. Williams lists 41 compressor stations on its 3,900-mile Northwest Pipeline alone.

Compressor stations matter to residents because they are where neighbors meet the pipeline. They make noise, they burn gas and emit NOx, and they occasionally vent gas during maintenance or emergencies. Lesson 7 covers them in detail.

Storage

Gas demand in winter can run far above summer demand. In January 2025, US consumption averaged a record 126.6 Bcf/d for the month by EIA's count, while the 2025 annual average was about 92 Bcf/d. Production cannot swing that much. Storage covers the gap. Most US storage sits in depleted oil and gas reservoirs, with the rest in aquifers and salt caverns. Salt caverns are small but can inject and withdraw quickly, which makes them valuable for power plants that need gas on short notice. EIA describes the normal cycle as injection from about April through October and withdrawal from about November through March. Its October 2026 outlook expected working gas to reach about 3,850 Bcf at the end of October, roughly 2% above the five-year average.

Local distribution

At a city gate, the transmission line hands gas to a local distribution company. The utility drops the pressure, adds the rotten-egg odorant (mercaptan) and sends it through mains and service lines. Large gas power plants usually skip the utility and connect directly to a transmission line through a lateral pipe, which is why a new plant often comes with its own pipeline permit.

LNG

Liquefied natural gas is gas chilled to about minus 260 degrees F, shrinking it roughly 600 times so tankers can carry it overseas. The US became the world's largest LNG exporter in 2023 at 11.9 Bcf/d, ahead of Australia and Qatar. EIA puts 2025 exports at 15.1 Bcf/d and forecasts 17.6 Bcf/d for 2026. That is a lot of gas: 2026's forecast exports would equal about 16% of forecast US production. EIA names rising LNG exports as one factor in the 2019 to 2022 price climb. Export growth links US gas prices more closely to Europe and Asia than they used to be.

Who regulates what

Piece	Siting and rates	Safety	Air and water
Wells and gathering	State oil and gas agency (and BLM on federal land)	State agency; PHMSA for some regulated gathering	State environmental agency, EPA
Interstate pipelines, compressors, storage	FERC (Natural Gas Act section 7 certificates, rates)	PHMSA, often with state partners	State air permits, EPA; FERC's environmental review under NEPA
Intrastate pipelines	State agency or PUC	State program certified by PHMSA	State
LNG export terminals	FERC (siting); DOE (export authorization)	PHMSA, Coast Guard	State, EPA
Local gas utility	State public utility commission	State pipeline safety program under PHMSA	State

FERC's own page lists its jobs: regulating construction of interstate pipelines, storage and LNG facilities; issuing certificates of public convenience and necessity; approving abandonment; and setting rates for interstate transportation. It does not set the price of the gas itself (that was deregulated decades ago), and it does not regulate the local utility's retail rates.

PHMSA, part of the US Department of Transportation, writes and enforces pipeline safety standards through its Office of Pipeline Safety, keeps incident data and runs the National Pipeline Mapping System. Many states inspect intrastate and distribution pipelines under agreements with PHMSA.

The eminent domain piece

The Natural Gas Act at 15 U.S.C. 717f(h) gives a FERC certificate holder the power of eminent domain when it cannot buy the right-of-way by agreement. The case can be filed in federal district court where the land sits (when the owner claims more than $3,000) or in state court. That clause is why a FERC certificate is the moment a pipeline fight turns from persuasion to condemnation. Lesson 7 picks this up.

How gas reaches the Northwest

The Pacific Northwest and much of the Intermountain West produce little gas of their own. They depend on two long-haul systems and the basins at their ends.

System	Operator	Route and size	Supply
Northwest Pipeline	Williams	About 3,900 miles through Washington, Oregon, Idaho, Wyoming, Utah and Colorado; peak design capacity 3.8 million Dth/d; 41 compressor stations; 14 million Dth of seasonal storage	Rocky Mountain basins, Canada (British Columbia and Alberta), San Juan Basin
Gas Transmission Northwest (GTN)	TC Energy	From Kingsgate on the British Columbia border to Malin, Oregon, at the California line; average design capacity 2,900 MMcf/d; about 1,377 miles long per the Oregon attorney general's office	Western Canadian Sedimentary Basin

GTN's route crosses the northern tip of Idaho on its way from Kingsgate into Washington. TC Energy's own page lists deliveries to Washington, Oregon and California without naming Idaho, so check current maps before you describe the route. Local utilities across Idaho, Oregon and Washington take gas off these lines at city gates. When TC Energy proposed adding 150 million cubic feet a day to GTN in 2021 and 2022 (the GTN Xpress project), the attorneys general of Oregon, Washington and California intervened at FERC and asked it to deny the expansion on climate and need grounds. That fight is a clean example of how a pipeline docket becomes a state policy argument.