A Closer Look at the Environmental Consequences of Fracking

wastewater from fracking

This containment pond holds contaminated water produced by the fracking process. (Photo credit: Dwight Nadig/E+/Getty Images)

While not exactly a new technology, fracking (which is short for “hydraulic fracturing”) has been a common topic in the news recently. Fracking is known both for its potential to ease U.S reliance on foreign sources of energy and for its possible adverse effects on the environment, which scientists now think include the potential for starting earthquakes.

The city of Youngstown, Ohio, is known for many things. Its main claim to fame, of course, is the production of steel, but it also is home to many other manufacturing plants and, perhaps as a consequence, has historically been a hotbed for organized labor. One thing no one would probably ever associate with Youngstown, however, is earthquakes. In fact, since record keeping for the area began in the late eighteenth century up to 2010, there had never been a recorded earthquake. From 2010 to 2013, however, as many as 109 tremors were recorded. This change in seismic activity corresponded with the NorthStar 1 well going on line. NorthStar 1 collected the wastewater byproducts from fracking, a method for collecting natural gas and other fossil fuels trapped in porous rocks deep within Earth.

Fracking involves drilling wells deep into the Earth, sometimes as deep as 7000 feet (2133 meters), the equivalent of six Empire State buildings. The target is porous rock, such as shale, which, because of its porosity, often holds trapped natural gas. Long steel tubes are drilled horizontally outward into the rock to form a kind of network. The steel tubes have holes like a colander, and mining begins when water containing sand and other chemicals is forced down into them at high pressure. The water pressure causes the rocks to fracture, thereby releasing the trapped gases. The gases dissolve in the water, and, eventually, the pressure will force the water back to the surface, where the gases are collected. Estimates predict that, at its current rate of growth, fracking will account for more than half of the natural gas produced in the U.S. by the year 2035.

Thus far, the majority of the controversy surrounding fracking has had to do with the composition of the water solution used to fracture the rocks. It contains all types of chemicals that could potentially pollute groundwater sources. Most geologists contend that contamination from the water coursing through the horizontal veins deep within the rocks is practically non-existent. The pipes that carry the water to and from its destination, however, often run straight through sources of groundwater. Pipes breaking and contaminating groundwater on the water’s journey either from or to the surface is not a difficult prediction to make. Also, while the actual “action” behind fracking occurs deep below Earth’s surface, fracking is still hard-core mining, and tears up a lot of land. Natural gas might be a nice, clean burning fossil fuel, but getting it to the surface in this way poses risks. Fracking also releases a fair amount of methane, which is a greenhouse gas. So, while we may be getting a clean burning fuel, the greenhouse gases released in the process of getting it might cancel out the good effects.

Likewise, it’s also not hard to believe that the act of fracking can encourage earthquakes. Because it’s done so deep in the ground, and because of the extremely high pressures, fracking can generate a considerable amount of disturbance in the rocks. Earthquakes occur on faults, which are fractures in rocks along which movement can occur. If fracking is carried out too close to a fault, it’s not unreasonable to assume that the delicate forces existing among the rocks might get upset and trigger an earthquake.

Interestingly, however, it’s not exactly the fracking that’s so worrisome to many geologists. It’s the disposal of the waste products. Remember, the water solution used to initiate fracking contains a lot of chemicals. When miners are done getting the natural gas from it, those chemicals still remain. The water needs to be disposed of somewhere, and many believe the best way to dispose of it is to inject it into deep underground wells, like the NorthStar 1 well near Youngstown. Fracking sites are carefully chosen. Before engineers will begin a frack, they want to make sure they’re not in danger of being near any geologic fault. The concern is purely practical: they want to mine gas from as much solid rock as possible. The wells dug for the disposal of the wastewater, however, carry no such logistical concern. What is more, while the total water “in the ground” at any one fracking site may not be that much, stashing all the wastewater from fracking can create a considerable “backlog” of contaminated water that needs to go somewhere. Underground wells intended to serve as the waste receptacles for fracking debris therefore not only are less scrutinized than fracking sites, but they also need to accommodate a great amount of water. The water and the pressure it brings only increases the possibility that it could cause a disruption to a nearby fault.

There is some room for optimism.  As the waste from fracking sites increases, and will continue to do so, companies are finding it more and more profitable to find ways to recycle the waste. While it may not end up as drinking water, it can be reused for mining or for other purposes. Recycling the water also reduces the costs involved in ferrying new and used water to and from drilling sites in large trucks. Some estimates predict that, in certain areas, recycling can reduce the costs of water for the mines by as much as $2 a barrel. The challenge now is to encourage those running mining operations in states where waste disposal sites are plentiful, and so less expensive, to choose recycling instead of disposal.

More to Explore
How Oil and Gas Disposal Wells Can Cause Earthquakes
What is Hydraulic Fracturing?
Is Fracking Safe? The Top 10 Controversial Claims About Natural Gas Drilling

 

This article was originally published on EcoZine in May 2014.

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