As the Russia-Ukraine war intensifies energy supply challenges, shale gas development in the U.S. is gaining traction. Shale gas has the potential to be a game-changer in the energy market, but it also poses significant environmental risks. The toxicity of chemical additives, disposal of recovered water, and greenhouse gas emissions from hydraulic fracturing techniques need to be addressed.
With the Russia-Ukraine war dragging on for so long, we’ve all heard about the gas supply issues between Russia and Europe and the United States. This issue is not just a geopolitical conflict, but a more complex change in the energy market. For example, Russia’s monopoly on gas supply has begun to falter as shale gas development in the United States continues to grow. Shale gas has the potential to be a game-changer for the energy industry, threatening the traditional natural gas market. However, shale gas development also poses environmental risks. What are the environmental risks of shale gas?
First, let’s take a closer look at what shale gas is: it’s unconventional natural gas, which is hydrocarbons buried in layers of sedimentary rock (shale) that have been hardened by years of sand and mud. While it has the same chemical composition as conventional natural gas, shale gas is different because it is located in shale formations. To extract shale gas commercially, two key technologies are required: horizontal drilling and hydraulic fracturing. Because of this technical complexity, shale gas is categorized separately from conventional gas.
When discussing the environmental risks of shale gas development, the first thing that comes to mind is the risk of chemical additives in hydraulic fracturing fluids. The fluid used in hydraulic fracturing is not just water and sand; it is composed of 90% water, 8.95% sand, and 0.44% chemical additives. Although the chemicals are added in small amounts, the absolute amount is not negligible. Since the volume of hydraulic fracturing injection fluid is approximately 2,700,000,3,800,000 gallons (10,220,000,14,384,000 liters) per well, the total amount of chemical additives is significant. These additives contain ingredients that can cause acidification of soil and groundwater or cause chronic diseases in humans. But the bigger problem is that the full composition of these chemical additives is not disclosed by the companies that develop them, citing trade secrets. This is a major concern for environmental organizations, as it makes it difficult to determine whether additional harmful additives are present.
Secondly, there is the issue of recovery disposal. When the pressure is released after fracking, a mixture of hydraulic fracturing fluid, shale gas, and methane gas rises to the surface, known as “flowback water.” Typically, between 20 and 50 percent of the hydraulic fracturing fluid is recovered. Currently, there are two ways to treat flowback water. The first is to reuse the flowback water in the hydraulic fracturing process, but this is not a fundamental solution because the concentration of chemical additives becomes increasingly high, and there is no way to dispose of the flowback water after the fracturing process ends. The second option is to dispose of the water by injecting it deep underground. This method is likely to cause serious environmental problems in the long term, such as groundwater contamination, as the chemical additives and radioactive materials contained in the water are disposed of untreated.
There are many other environmental issues associated with shale gas development. For example, shale gas development releases far more greenhouse gases than traditional natural gas. This is considered one of the main factors contributing to accelerating global warming. In addition, the process of hydraulic fracturing can cause mild earthquakes with a magnitude of 1-3, which can lead to land subsidence. Excessive water use is also an issue that cannot be ignored, and water scarcity is likely to increase in areas where shale gas development is taking place.
Despite these risks, however, the need for a reliable supply of energy is an important global issue. Shale gas is considered an important resource to address this energy supply challenge and remains a difficult option to abandon, especially for countries aiming for energy independence. Therefore, there is an urgent need to develop alternative development technologies other than hydraulic fracturing, or to find eco-friendly additive combinations that can replace harmful chemical additives. In addition, legal and institutional mechanisms should be put in place to mandate the purification and treatment of recovered water and thoroughly manage it. This is not just a matter of environmental protection, but also an essential step towards sustainable development of energy resources in the long term.
