Why Is Fracking Harmful?

In the world’s pursuit of petroleum and natural gas, the technique of fracking—injecting a liquid at high pressure into underground rock to open fissures and release natural gas or crude oil—surged starting at the end of the 20th century. Although fracking processes had been developed decades earlier, technological advances—including steerable drill bit motors (which allowed for horizontal boreholes that accessed hard-to-reach oil and gas deposits) and telemetry (which helped operators monitor the fracturing process with great precision)—did not become available until the 1990s. The boom in natural gas and petroleum production that has resulted from fracking has added to the world’s fossil fuel supplies while also increasing the concentration of greenhouse gases in the Earth’s atmosphere. At the same time, the fracking process also creates problems at the surface and underground.

How does fracking work?

What sets fracking apart from traditional petroleum exploration and recovery is the use of explosives. After the borehole is made, a conductor casing, a steel pipe 40–50 cm (16–20 inches) in diameter, is used to line the hole. When the operators drill to where they think the natural gas or petroleum deposit is, they perforate that part of the casing and fire small, aimed explosive charges through the wall of the pipe that crack the rock. Fracking fluid (a mix of fresh water, sand, and chemical additives) is pumped into the borehole and into the perforations under great pressure, which widens the cracks in the rock, freeing the gases inside. The liberated gases, along with the fracking fluid, are collected by tubing sent down the well and brought back to the surface to be stored; crews then work to recover these valuable fuels

Contamination and pollution issues

Fracking presents environmental risks. The fracking process contaminates the fresh water it uses as a working fluid (which later becomes wastewater), and it can pollute local sources of water used for drinking and irrigation. Used fracking fluid is discarded in disposal wells or in rock formations deep underground. Treated wastewater, however, is often released into surface waters. This fluid still contains contaminants but at levels below those set by governmental regulations. Some organizations maintain that fracking wastewater can be treated to be made safe for irrigation, but it cannot be used for drinking.

Not only do fracking operations extract water from aquifers (that is, water-bearing layers of permeable rock, sand, or gravel) for use as fracking fluid but also a number of studies have determined that the fracking process can contaminate groundwater. However, industry officials have long attempted to reassure the public that fracking is safe (since it often takes place in layers of shale or other fuel-bearing rock deep below aquifers). Gas wells are often drilled through aquifers or in rock near aquifers, and thus the gas wells can pose a risk to local water sources. Studies note that contamination is more likely when fracking crews make mistakes or are negligent. According to the U.S. Environmental Protection Agency, the risk of groundwater contamination increases when:

• spills of fracking fluids, wastewater, and other chemicals occur at the surface;
• fracking fluids are inadvertently injected directly into the aquifer;
• rocks below the aquifer lack the strength to contain released gases and fracking fluids;
• or fracking fluid, wastewater, and recovered gases and liquids are improperly treated or stored.

Frackquakes

Fracking also poses another concern: It can result in seismic activity (which is also known as “frackquakes”). Drilling and pumping operations produce vibrations that can be detected by sensitive instruments. Sometimes, however, small tremors and even earthquakes magnitude 4.0 or higher have been recorded in some areas where shale gas is being developed (see also moment magnitude). These disturbances can be felt by residents nearby, who may find them disconcerting, especially if they occur in areas where earthquakes are rare. Furthermore, geologists also worry that the underground disposal of large amounts of drilling and fracking fluid may alter the pressure balances between rock layers or even lubricate existing faults in rock formations that are already liable to slip.