Leaks and other losses of gas occur throughout the fossil gas system, due to a multitude of diverse processes.
Across the country—from North Dakota to Texas, and from California to Pennsylvania—there is leakage in gas fields, where gas is extracted from rock deep underground. There’s leakage along the network of transmission pipelines that carries gas to cities. And there’s leakage in the cities, from distribution pipelines that snake under the streets and up to buildings, and from appliances inside buildings.
Recent research has filled in many gaps in our knowledge, showing that the U.S. gas system is significantly leakier than had been thought. (For more information, see the page on implications of methane leakage.)