Salty, chemical-laden fluid leaked for two hours before anyone from Vantage Energy let Arlington city officials knew there had been an accident at the hydraulic fracturing well next to the Baptist church. It would be another 22 hours before they plugged the leak. In that time, 42,800 gallons of polluted liquid would flow into the sewers and streams of this suburban city wedged between Dallas and Fort Worth.
That was two months ago, and this week Arlington officials announced their investigation into the accident---caused by equipment failure---was complete. After taking water and soil samples, they announced that the waste water spewed from the well did not cause any significant damage to the environment. Vantage Energy's biggest sin was not notifying the city of the accident when it first occurred. Even with this conclusion, the spill has raised concerns in frack-friendly Texas and beyond.
Natural gas has been touted as the bridge fuel---the climate-friendly alternative that will fuel society until green energy gets up to scale. Then faucets started catching fire in Pennsylvania. And earthquakes started shaking Oklahoma City. And evidence started accumulating that indicates the gas itself is a bigger threat to the climate than coal.
But all these problems tie back to the processes used to produce natural gas. The question is, could these processes be fixed so natural gas fulfills its promise as a climate change panacea?
Fracking, or hydraulic fracturing, uses high-pressure slugs of chemicals, water, and sand to crack shale formations deep underground, unlocking methane gas trapped therein. America has been fracking since the '40s, but production didn't really take off until 2005. That year, the Bush Administration's EPA exempted fracking from the Safe Drinking Water Act. This opened the fracking floodgates. "Half of shale gas produced in history has been produced in the last 4 years or so," says Robert Howarth, an environmental scientist at Cornell University.
The EPA's 2005 decision was based on the notion that fracking's chemical-laden water would stay deep in the earth. About 20 to 40 percent of the fluid used to crack open a shale play comes back to the surface. Drillers typically inject it into old, dried out wells, or other deep sites. "The disposal of the fracking return fluids remains a big challenge," says Howarth.
Even when it isn't burbling unbidden to the surface (Arlington-like accidents are exceedingly rare), things like burning faucets in Pennsylvania show that injection isn't always permanent. In this case though, it would be wrong to focus on fracking's waste water disposal problem---a single barrel of oil produces ten barrels of waste water. "The appropriate response is to figure out better well casing and surface handling procedures for all oil and gas," writes Danny Reible, a chemical engineer at Texas Tech University in Lubbock, in an email.
Another solution is treating the water, either so it can be recycled and used again for other oil or gas projects, or clean enough for drinking or agriculture. The biggest hurdle to both options is logistics. Relying on treated water means a frack or oil play might not have water on demand. And shipping waste fluid to a treatment plant takes trucks, pipes, or trains. Infrastructure like that costs big money. Also, trucks can crash, pipes can burst, and trains can spill. It seems like water flows to places that are very inconvenient for gas industry public relations people.
And filthy water isn't the only thing these wells belch out. Groundwater injection has also been linked to earthquakes. So far most have been relatively small---though some have reached up to 5.7 moment magnitude---but they happen in places where people are unused to the ground shaking. "In a few places because there have been earthquakes bigger than 4.5 and 5.5 caused by humans. The codes here aren’t used to them," says Cliff Frohlich, a seismologist at the University of Texas in Austin. "The sensible approach would be to have zoning where you're not doing injection disposal in the middle of cities like Dallas or Oklahoma City."
Frohlich nominates the vast empty spaces of west Texas, where a 5.5 earthquake would shake like a tree falling in a forest with no one around to hear it. But, he points out, shipping the water to be injected elsewhere has the same logistical problems as does treating it. "You have to ship it, it spills, you're dealing with chemicals," Frohlich says. "People are probably more exposed to the water if you treat it than if you pump it into the ground."
Then there's the methane problem. Despite all the worries over fracking, natural gas is clean-burning. In the climate change-worried world of environmentalism, this has been the trump card. The issue is with methane that escapes before it can be burned. Over the past four years, a series of research papers have shown that fracking has very likely caused a huge increase in atmospheric methane.
Methane is a greenhouse gas, which means it traps energy and turns it into heat. And it is particularly potent. "If you cut methane emissions, you would stop global warming over the next few decades," says Howarth, who was among the first to notice that fracking wells were releasing the gas. Shutting off these near-term temperature increases from methane would take some spark out of the fuse on the carbon bomb set to go off in the next few decades. (Carbon dioxide is a more potent greenhouse gas, but takes many decades to release its stored energy as heat.) "This idea that methane gas is a bridge fuel, is better than coal, is nonsense," he says. Stronger regulations could help curb these unintentional emissions, but Howarth says resistance from gas companies means scientists still don't know the extent of the threat.
The common thread in all these problems---and their potential solutions---is uncertainty. Uncertainty is the story of fracking. Recent changes---like a federal law passed in March making it mandatory for companies to disclose the ingredients used in each well---have helped, but each flow like that seems to be accompanied by an ebb. Like the Texas legislature's decision last month to make it illegal for municipalities---like Arlington---to ban hydraulic fracturing. Speaking of Arlington, that faulty well has been repaired, and is one inspection away from reopening.
