An Invisible Leak, With Glaring Consequences
It’s been over two months since inspectors uncovered a colossal natural gas leak in California’s Aliso Canyon, and it will take at least another month, possibly two, to plug it up, according to the Southern California Gas Company’s latest estimates.
The invisible methane plume, captured on infrared camera by the Environmental Defense Fund, has driven thousands of nearby residents out of their homes, shut down two schools, and cancelled out a chunk of the state’s greenhouse gas reduction efforts. Rob Jackson, an environmental scientist at Stanford University, walks us through what’s been happening in California and why it’s so hard to plug up this geyser.
Rob Jackson is an environmental scientist at Stanford University in Stanford, California.
MANOUSH ZOMORODI: This is Science Friday. I’m Manoush Zomorodi, host of WNYC’s Note to Self podcast, sitting in for Ira Flatow.
It was late October, when residents of Porter Ranch California first noticed the smell of rotten eggs. It turned out, natural gas fields in nearby Aliso Canyon had sprung a massive leak. Spewing about 100,000 pounds of methane into the air each hour. California has declared a state of emergency. Thousands of people have relocated. And some have called this the worst environmental disaster since the BP oil spill.
But the Southern California gas company now says it will take until February, if not march, before the leak can be plugged. So why is it taking so long? Rob Jackson is an environmental scientist at Stanford and he’s been monitoring the situation in Aliso. Are you in California listener? How has the methane leak affected you? You can call us at 844-724-8255. That’s 844-SCI-TALK . Or tweet us, @scifri.
Rob, thanks for being here.
ROB JACKSON: Thank you, Manoush.
MANOUSH ZOMORODI: So can you explain to us, what exactly is this natural gas storage field?
ROB JACKSON: Well the Aliso Canyon storage field is one of about 420 places around the country where companies pump natural gas underground to store it. It provides a stable supply, but they also do it to speculate on the price. They can pump gas underground in summer when natural gas prices are low, and then pump it back out in winter people are using it to heat their homes, and the price is higher.
MANOUSH ZOMORODI: So why– how did they figure out that they could do this? How long have we’ve been doing this for? And where does that space underground come from?
ROB JACKSON: Well we’ve been doing this for 50 years, or more than 50 years. Most of the gas storage fields are old oil and gas fields. Imagine pumping the oil and gas out over decades. You have lots of open pore spaces available underground. And because the field stored natural gas for millions of years, when you put it back underground, the chances are, it will stay there. Unless you have an accident with the well itself, which is what’s happened here.
MANOUSH ZOMORODI: Yeah we’ll get to that one, right? But so, physically, I’m sort of imagining caves, but that can’t be right.
ROB JACKSON: No, it’s not really like a cave, say in, Carlsbad Caverns, that listeners might of walked through. It might be more like, a honeycomb, as a better analogy. There are cracks and pore space . It’s not something you can walk through or swim through, or anything. But there’s just lots of open space available underground.
MANOUSH ZOMORODI: And how do we actually get the gas to out, then? How do we pump it?
ROB JACKSON: Well in these storage field, the Aliso Canyon field was an oil field. Has about 115 old wells on it that used today for storage. So what used to be a well that was used to pump oil out of the ground, is now a well that’s used to pump natural gas back down into the ground, and then back out of the ground when it’s extracted.
MANOUSH ZOMORODI: And is that where the problem could be then? The pipes and cement that get the actual gas out?
ROB JACKSON: That is where the problem is. There’s a particular well at this location that began to have a problem, at least as early as October. And the company made efforts to use mud and brines. And imagine pushing heavy fluids down that well to try and counter balance the pressure of the gas that first started coming out. And they tried all of that and it failed. And eventually the gas started bubbling down and out around the cement sheath and through the rocks up into the air. And at this point, it’s an uncontrolled release of a natural gas that’s just belching natural gas. About 2.5 million pounds of methane every day.
MANOUSH ZOMORODI: And you’ve been driving around there right? Tell me what you’ve seen and how you’re going about monitoring these natural gas concentrations.
ROB JACKSON: Well, we’ve been driving. They’re lots of other folks that are taking measurements in the area, because it’s so important. So when we drive what we see is– well first of all, we’re using a laser, a [? bacar ?] laser that gives you an instantaneous reading of the methane concentration. And imagine putting that laser in a car where you have a sampling port out front, and you drive, fairly slowly, block by block, and sense the concentration of methane in the air.
So what we’re finding is that in parts of Porter Ranch we don’t see any increase in natural gas concentrations at all. But when the wind is in the right direction, and that’s key. And when you’re in the upper part of Porter ranch, near the gas field, then we start to see really high concentrations of methane.
Now they’re not so high that there are a health risk to people. The health concern really is what other trace gases might be in the air, such as benzene, which is a carcinogen. Or hydrogen sulfide, which is poisonous.
MANOUSH ZOMORODI: And so the people who are complaining of dizziness, or nose bleeds, or headaches, what could be causing that?
ROB JACKSON: That’s probably being caused by the mercaptans. The mercaptans are sulphur compounds that companies put into natural gas to give it an odor. Methane doesn’t have a smell. And we began doing this in the US in the 1930s when a school in Texas blew up. Killing several hundred people. And after that point in time, everybody started putting these odorants in the gas. And those odorants can be irritating. They can cause breathing issues, runny eyes, nose bleeds, and things like that. Were very, very sensitive to mercaptans, and that’s why they’re used.
MANOUSH ZOMORODI: OK. So let’s say let’s take a call. I think we’ve got Ken from Mayville, Wisconsin on the line. Hi, Ken, it’s Manoush here, Science Friday.
KEN: Hi, I actually grew up on Aliso Canyon, right there. My parents still live in the house that I grew up on. It’s the last– last row of houses before you go into that gas field. It’s not the first time anything like this happened. Back in the ’70s, when we first moved there, I believe it was like ’73-’74, one of the wells actually blew up. They had [? red ?] [? air, ?] came in, they burned for about a month or so. It blew out at one time, [? from the Santa Ana ?] [? winds ?]. The had to re-light it, because they were afraid the whole San Fernando Valley would blow up from the [? tank of ?] gas into the valley.
MANOUSH ZOMORODI: And so, what would you do then? Would use sort of leave the area for a while?
KEN: Well, when that well blew up, and it was burning, it was ignited gas. So it was turning off. This, right now, from what I get my parents, most of the neighbors have moved out of the neighborhood. And they don’t really smell it, or how much effect from it. Yeah, it is– been a big concern with everybody in the neighborhood.
MANOUSH ZOMORODI: Thank you so much for calling. So Rob, let’s talk about what’s been tried so far to plug the leak.
ROB JACKSON: First of all, the callers right, I will get to that Manoush, really quickly. And there were two oil well blowouts. One in 1968 and one in 1975. In terms of what’s been done. As I mentioned, the first thing that the company might typically try and do is to provide back pressure. When you have a blow out, or the possibility of a blow out, you have pressure in the gas, or the liquid, that’s percolating up to the surface.
So one way you can counter balance that is to push back down on it. And the way companies push back down on it is to use things that are dense, such as clays. You take water and put a lot of salts and turned into a brine like a very, very heavy sea water. So you push these back down. And this was tried multiple times at Aliso Canyon, and it just didn’t work.
And then they started having trouble with freezing underground. And lots of interactions that began to force the gas out, and then into the rock, and up. And also began to destabilize the well itself. So the only way this could get worse, would be for the well itself to just rupture at the surface, and have the leak actually coming right up the steel tube into the atmosphere. And that’s not happening right now.
MANOUSH ZOMORODI: So when the caller says if this has happened before, can you put it in context how this current situation compares, in terms of how damaging it could possibly be, to the environment?
ROB JACKSON: It’s quite different. What happened before was a blow out in an individual oil well. Much smaller scale. It doesn’t mean that those individual blowouts can’t be dangerous, and it doesn’t mean the people can’t be hurt from it. But on a scale of actual emissions of the size of the leak, this is dwarfing anything that’s happened like that before, in this area. Or really, almost in any other area in this country. This is very unique and very unusual.
MANOUSH ZOMORODI: And just put it into context. Like how big is it? I guess is the question.
ROB JACKSON: The leak as I think I mentioned before, is about 2.5 million pounds of natural gas every day.
MANOUSH ZOMORODI: What you compare that to? Like for me, I have to say that, it doesn’t mean much.
ROB JACKSON: Here, I know I’m a scientist. I’m sorry. I’m struggling. Hold that thought and I’ll see if I can come up with a better analogy. I mean, you can think of it maybe, just in terms of the leak itself, sometimes I use the analogy of a balloon. And you can think of these underground storage fields as a balloon underground they just keep pumping gas into. It gets very, very high pressure. And if the knot on that balloon comes untied, then the gas jets out. And it takes a long time for that air to finish. It just keeps jetting out. And that’s what’s happening in Aliso Canyon.
MANOUSH ZOMORODI: Let’s take one more call. We’ve got a question from I believe, Samuel in New York City. Hi, Samuel, you’re on Science Friday.
SAMUEL: Hi, there. Well one of the questions I had was, what do you think– how does it affect the water table? Because I know, over here in New York, in Upstate New York, they’re really concerned about fracking and how that would affect the public water table. How do you think this natural gas spill, in itself, will effect– and what are they doing to fix it?
ROB JACKSON: I don’t think it’s likely the this leak will have a big effect on the water table. It is possible. The leak is about– or the breach appears to be about 500 feet underground. Less than 1,000 feet. It’s also up on a mountain, or 1000-1,200 feet above the surface. So is it possible there could be water interactions? I guess it is. It’s not something that I think is likely. And it’s not something, honestly, that I’ve looked at or know that much about.
MANOUSH ZOMORODI: Samuel, thanks so much for your call. And in terms of the greenhouse gases then, is that the real fear here? In terms of the long term effects, Rob.
ROB JACKSON: I think there are three issues that people are concerned about. The greenhouse gas budget is one. And you ask me for some context on what 2.5 million pounds a day is. One way to place it in context is to look at California as a state. And this leak is bigger than the methane that’s emitted by all industrial activities in California. Including the entire oil and gas industry. So everything else– everything in the state that’s going on. It’s huge. So that’s one concern.
In terms of the global methane budget, it’s not– it’s not huge. You’re not going to see a massive spike in the atmosphere because of this leak. It’s huge, but it’s not that huge. The second issue, that’s probably also not a huge concern, is the interaction with ozone. Los Angeles and its air, it has a problem with ozone.
The ozone in Los Angeles is catalyzed by hydrocarbons, rather than a nitrogen oxides. But it’s not typically catalyzed by light hydrocarbons, such as methane and ethane. And it’s also winter, and it’s rainy, but that would only likely be an issue if this went into the summer. And even then it might not be.
But the biggest issue, and the thing that people are most concerned about, are the trace gases. What else is in that air, at low concentrations, that could cause health effects long term.
MANOUSH ZOMORODI: Rob, unfortunately we have to leave it there. I can’t thank you enough for explaining this to us. Rob Jackson is an environmental scientist at Stanford.