An Explanation of the Microbial Complications of Fracking
Several years ago, land owners in the forested rolling hills of West Virginia started getting unannounced visitors. They would examine the land, the soil, the trees, and offer to lease part of the property for $7 per acre up-front, plus a share of the profits that would inevitably come from the activities they had planned. These men were representatives of energy companies – Chesapeake, perhaps, or Total – and they wanted to drill for coal and natural gas. They really wanted it: landowners who stood their ground were ultimately offered up to $3,000 per acre.
The resulting rush of activity brought rapid and stark changes to a region largely left behind by previous episodes of economic growth. Toggling between satellite images taken a couple of years apart shows the appearance of drilling rigs, wastewater retention ponds, and storage tanks, pockmarks of activity across this rural swath of Appalachia.
Yuri Gorby grew up in the small town of Bethany, West Virginia, and recent visits to his hometown have left him flabbergasted. He saw an environmental catastrophe unfolding before his eyes, and the experience awakened a simmering activist streak that is never too far from the surface.
Gorby, an Associate Professor of Biological Sciences at the University of Southern California, made his scientific name not in environmental science, but in microbial physiology. (He is a leader in the study of microbial “nanowires,” conductive filaments that allow organisms to transfer electrical energy via direct contact.)
The changes on his family’s land compelled him to shift gears, but as dramatic as the surface developments have been, they’re nothing compared to the changes underground.
This transformation derives from the boom in natural gas production facilitated by horizontal drilling technology, hydrological fracturing (or “fracking”), and the 2005 Energy Policy Act.
The most transformative breakthrough that led to the current situation was horizontal drilling, a Halliburton technology that allowed a single drilling rig to access a subterranean landscape in three dimensions rather than just one. Fracking involves explosive charges that broaden conduits for gas and fluid flow into the drill pipe. The technology is old news – it’s been around for several decades – but the new geometrical possibilities made the approach significantly more pervasive. Suddenly, vast expanses of rock formations (read: the Marcellus Shale) were economically viable.
Lawmakers were eager to promote the technology; the landmark Energy Policy Act exempted horizontal drilling and hydraulic fracturing from the regulations of the Clean Air and Water Acts. “When we have the precedent that you can’t be punished for environmental transgressions,” Gorby objects, “it becomes very difficult to protect our water supply, and that’s the whole issue here.”
Microbes are responsible for key parts of the process that generates natural gas, but during its recovery, they are the enemy. Sulfate reducing bacteria – which use sulfate ions in the water for energy – spit out sulfide, a toxic molecule that “sours” the gas product. To combat this process, biocides like formaldehyde and gluteraldehyde are thrown down the pipe in an attempt to preserve a usable product.
The environmental complications of microbial involvement are thus twofold. Initially, the toxic biocides inevitably leak into the surrounding rock and aquifers, and since these poisons are non-specific, there’s a lot of collateral damage. Later on, after older wells are abandoned, sulfate reducers come back with a vengeance, generating acidic byproducts that can corrode pipes and release heavy metals.
Local residents are aware of the dangers that fracking has brought, and they’ve adjusted: “they all drink bottled water now,” says Gorby.
The issue isn’t going away any time soon. Natural gas contracts signed when prices were $11 per 1000 cubic meters were for monetary equivalent gas volumes; now that the price has sunk to about $2 per 1000 cubic meters – an effect largely due to the glut of production associated with new fracking technologies – more than five times the originally planned gas must be found. With even more pressure to produce on one side and an increasingly vocal opposition on the other, the fracking firestorm is only going to get hotter.
Gorby willingly acknowledges that we don’t actually know for certain what’s going on, but to him, that’s the real danger. “We need to have the opportunity to collect scientific data and evaluate future risks prior to disrupting these subsurface systems.” Until we’ve got a better handle on the effects, Gorby supports a moratorium on fracking activities. It’s certainly a compelling scientific and environmental case, but Gorby may get the most traction with energy companies through an economic argument. “The price of methane is rock bottom right now,” he notes. “The gases have been down there for 350 million years; they can wait another ten while we figure out exactly what we’re doing.”
NOTE: Jeffrey Marlow is a graduate student in Geological and Planetary Sciences at the California Institute of Technology where he studies exotic microbial metabolisms in an attempt to understand the limits of life on Earth and beyond.