It's been nearly three months since the Aliso Canyon gas leak in the upscale community of Porter Ranch, CA was first discovered — and, even as that gas continues to spew into the atmosphere, experts are calling attention to the risks that aging fossil fuel infrastructure poses nationwide.
“Events of this size are rare, but major leakage across the oil and gas supply chain is not,” Director of Environmental Defense Fund’s California Oil & Gas Program Tim O’Connor said in a statement last month. “There are plenty of mini-Aliso Canyons that add up to a big climate problem — not just in California, but across the country.”
The Porter Ranch incident — where over 86,000 metric tons of methane have already been released, according to a counter posted online by the Environmental Defense Fund — involves a well that was first drilled back in the early 1950's. And then, in 1973, after the oil field was drained, it was repurposed and used as part of an underground methane storage field that can hold over 130 billion cubic feet of natural gas.
“It goes back into the history of oil and gas operations,” Cornell Professor Anthony Ingraffea recently told Living on Earth. “The well we're talking about was drilled in 1953, 1954. So it's over 60 years old, and it was never designed to last that long. It was designed to produce oil for some decades, then be plugged and taken out of service.”
Wells drilled decades or even a century ago dot the American landscape. Because many were first tapped before environmental laws were written, state and federal regulators often have no idea where they are located or to what extent they leak, but in 2011, ProPublica estimated that there may have been 12 million wells drilled nationwide over the past 150 years, the vast majority of them no longer in service.
The Aliso Canyon well, where a 7-inch casing ruptured, is unusual not for its corrosion, but because until October it was still being used to transport hydrocarbons.
And old metal pipes rust. “These are steel casings,” Prof. Ingraffea said. “They initially have some sort of corrosion inhibitor applied to them, but eventually after much use and flow of gases and liquids inside the casing, and exposure of the outside of the casing to natural gases and fluids, corrosion occurs.”
Across the U.S., hundreds of former oil wells have been repurposed as part of oil and gas storage fields. But millions more are no longer on anyone's books, and researchers say that those abandoned wells often continue to leak oil and gas because they were never properly plugged.
Some leak so much that they have become “super-emitters,” according to a paper published in the Proceedings of the National Academy of Sciences in Dec. 2014. The researchers sampled for methane at 19 abandoned wells in Pennsylvania — only one of which appeared in the state's official inventory of orphaned and abandoned wells.
“What surprised me was that every well we measured had some methane coming out,” Princeton Prof. Michael A. Celia said when the research was announced.
Methane is one of the most potent greenhouse gasses, trapping heat more than 86 times as efficiently as CO2 during the first couple of decades after it hits the atmosphere. So those leaks can have major implications for climate change.
The Porter Ranch incident has been called a climate catastrophe. “The enormity of the Aliso Canyon gas leak cannot be overstated,” Erin Brockovich, who is helping to organize lawsuits against Southern California Gas Company, wrote in a column published by MSNBC.
Thousands of residents have evacuated the area over concerns not only about the rotten-egg smell of the mercaptans added to stored natural gas, but also the potential short- and long-term health impacts of breathing in the fumes.
“Our community is starting to look like a ghost town,” David Balen, a councilman from Porter Ranch — a neighborhood that may look familiar to many Americans because it was where many of the street scenes in the movie “E.T.” were filmed — told Newsweek.
SoCalGas had known that its infrastructure was at risk for years, an investigation by Vice found.
“In 2014, written testimony to the California Public Utilities Commission by SoCalGas Director of Storage Operations Phillip Baker documented corrosion and negative integrity trends in the aging pipeline,” Vice reported.
“'Without a new inspection plan, SoCalGas and customers could experience major failures and service interruptions from potential hazards that currently remain undetected,' he wrote. The filing also noted that as of 2014, half of the company’s 229 storage wells were over 57 years old, and 52 wells were more than 70 years old.”
In fact, nearly half of the 111 wells used in the Aliso Canyon storage caverns were drilled before 1953. And when air quality inspectors arrived in December to check some of the other wells near SS-25, the well at the center of the disaster, they found 15 of the 16 wells they checked also suffered from “relatively minor” leaks.
It's not just oil wells that are aging, it's also the nation's inventory of pipelines used to transport oil and natural gas. Of the more than 1.6 million miles of natural gas pipelines, more than a third were built before 1970.
The risks are so serious that they've drawn the attention of the Obama administration's Secretary of Energy, Ernest Moniz.
“The natural gas system, the distribution pipes, are a big issue,” Moniz said in April 2015 at an event organized by the Christian Science Monitor. “About half of the distribution pipes in the country are 50 years old or older, so that’s a very obvious area.”
And the costs of maintaining that aging networks of pipes is projected to be enormous.
“If you look at aging infrastructure, the estimate just to replace all of the very old – like 50 years and older – natural gas distribution pipes, for both environmental methane leaks and safety reasons, is estimated at a quarter trillion dollars,” Moniz added.
Fracking Near Porter Ranch Methane Leak Site
In the Porter Ranch leak, another factor could be at play — the use of hydraulic fracturing, or fracking.
The SS-25 well itself was not fracked, state records show, but it is not uncommon for companies to frack gas storage sites to help compensate for damage to underground caverns from injecting gas underground. Another well near SS-25, SS-40, was in fact fracked, but that fracking took place at depths of over 9,000 feet, while the SS-25 leak is believed to be far closer to the surface.
“About two times a year on average, operators of gas storage facilities use hydraulic fracturing to enhance storage, mostly in one facility serving southern California (Aliso Canyon),” The California Council on Science and Technology noted in a January 2015 report.
The development roughly 15 years ago of high-volume hydraulic fracturing, combined with horizontal drilling, also spurred a shale gas rush nationwide — and researchers say that overall, the shale gas rush has leaked methane at unusually high rates.
Prof. Robert Howarth has been researching methane leaks from the shale gas rush for years, after co-authoring a landmark paper in 2011 that showed that natural gas production could be even worse for the climate than burning coal if enough methane leaked out.
Howarth now estimates that the shale gas rush has been remarkably leaky.
“The conclusion is that shale gas development during the 2009–2011 period, on a full life cycle basis including storage and delivery to consumers, may have on average emitted 12% of the methane produced,” Prof. Howarth concluded in a peer-reviewed paper published in the journal Energy and Emission Control Technologies.
By contrast, the Environmental Protection Agency's official estimates indicate that less than 2 percent of gas leaks nationwide. But the EPA's estimates have come under fire for a too-heavy reliance on industry-supplied estimates and because their numbers seem inconsistent with field measurements.
In the meantime, the disaster in Porter Ranch is adding significantly to California's methane emissions problem — increasing the entire state's leak rate by 21 percent. And many are concerned that what has leaked so far might only be the tip of the iceberg.
“The Aliso Canyon Storage Facility currently holds upwards of 137 billion cubic feet of natural gas,” Rep. Brad Sherman (D-Calif.) wrote in a January 6 letter to the EPA and other regulatory agencies. “We need to immediately investigate the best means to draw down this gas, and thus stop leakage much more quickly than the current plan.”
Image Credit: Screenshot from footage of the Aliso Canyon leak posted on YouTube by Environmental Defense Fund. That video has gone viral, with over 1.2 million views.