Natural gas leaks are dangerous and exacerbate climate change

Plus, enough gas has escaped infrastructure since 2010 to heat 170,000 homes for a year.

 

12.8 billion cubic feet.

That’s how much natural gas has been released since 2010 in nearly 700 “incidents” reported to the federal Pipeline and Hazardous Materials Safety Administration that occurred in the nation’s natural gas gathering and transmission systems. Another 36 million cubic feet of natural gas escaped during incidents from the distribution systems that deliver gas to homes and businesses during that time. Added up, it’s enough gas to heat more than 170,000 homes for a year.

Oil pipeline busts, like the one that wrecked the shoreline near Santa Barbara, California, recently, tend to get most of the attention these days — oil is sticky, nasty stuff. But natural gas infrastructure failures are equally alarming. Punctured natural gas pipelines can be dangerous. The reported incidents killed 70 people and injured more than 300. They can be expensive. Total costs in lost gas and property damage was nearly $700 million. And, all that natural gas is about 95 percent methane, an especially potent greenhouse gas.

Natural gas burns cleaner than coal: It emits about half the carbon dioxide per kilowatt hour of electricity generated, and doesn’t spew particulates, mercury or sulfur dioxide into the air. Since natural gas plants can provide round-the-clock baseload power to the grid, along with fast-ramping backup power, natural gas is the logical fossil fuel to replace coal in the electricity mix in a carbon-constrained world. But that logic is challenged when the production and movement of natural gas is considered. Methane can escape into the atmosphere during the drilling and hydraulic fracturing process; it’s emitted from processing plants and wells and, as the map above shows, large quantities of methane can escape when pipelines and other parts of the infrastructure spring leaks or are ruptured.

Methane’s global warming potential is about 30 times that of carbon dioxide over a 100-year period. So when a natural gas pipeline leaks, it cuts into the greenhouse gas benefits gained at the electricity-generation stage. In 2012, for example, a pipeline in Kern County, California, ruptured, allowing 585 million cubic feet of natural gas to leak into the air. That’s the equivalent of more than 230,000 tons of carbon dioxide. To put that in perspective, the San Juan Generating Station in northwestern New Mexico emits that same amount of carbon dioxide in a week, and the coal mine that supplies it releases about four times that (as methane) in a year.

The accompanying map shows every reported incident in the transmission and gathering systems across the nation since 2010. A browse through the reports reveals sometimes startling facts. Our infrastructure for moving this volatile gas is old, for example. Some of the busted pipes in the distribution system were installed more than a century ago, and 71 of the pipelines that ruptured or leaked in the transmission system were installed prior to 1950. Though the loss of life is rare, when a leak does lead to an explosion, the consequences can be dire. In 2010, an explosion in San Bruno, California, killed eight and injured 51. Browse through the incidents in your state to get a sense of how fragile the natural gas transmission infrastructure is, keeping in mind that surely many leaks go unnoticed and unreported.

Stay tuned to hcn.org for a similar map documenting oil pipeline incidents.

Jonathan Thompson is a senior editor for High Country News.