Water Use and Hydraulic Fracturing
Although an abundant resource across much of the United States, fresh water, is a precious resource that requires responsible use. Because hydraulic fracturing is a fresh water use intensive process questions have been raised regarding how water is, and should be, used. In shale natural gas extraction there is a general consensus among interest groups that the low water use-age ranges from 4-5 million gallons of water to 6-7 million gallons of water. (Shale_Gas_Primer_2009) Although, on a large scale, hydraulic fracturing uses a comparable amount of water to other industries there are certain conditions that are specific to hydraulic fracturing processes. Separating hydraulic fracturing from other forms of energy production, in terms of water used, is the loss of water from the natural environment. Where relatively large concerns lie are within the municipalities within densely drilled areas. Watersheds in close vicinity to drilling operations can be significantly impacted by acute water withdrawals. Fishing industries as well as wild predatory animals can be devastated by the loss of fresh water ecosystems. This has an impact on not only the environment but the human way of life.
Natural Gas as Energy Producer
When compared to nuclear power plants or even the coal burning power plants the overall water use in the energy production industries can be difficult to determine. The aggregate figures surrounding water use are difficult to determine because the hydraulic fracturing process uses consumption permits(See pg 5 image). This permit allows for up to 2,000,000 gallons of water per day for more than two years. The math is far from complex. The problem is that once a well is fractured the majority of water is left in the well. Consumption permits indicate that water is consumed and not re-introduced into the environment. In other power generating systems the majority of water is treated and distributed into major bodies of water to reduce negative impacts. 20-70% of water used in natural gas hydraulic fracturing is lost in the well. The by-product water is then disposed of in methods of which include waste water treatment. (EPA Fact Sheet). 70-90% loss of water at exploreshale.org.
Another major concern regarding fresh water is the contamination of drinking water. Because drilling is an extremely complex geo-technical process it requires discipline, oversight, and long term monitoring of drilled wells. There are many different claims regarding hydraulic fracturing process and groundwater contamination. These claims, seen from all interest groups, can range from one of the largest problems in the natural gas industry to no threat whatsoever.
Clarification
Important to note is that there are often thousands of feet of rock and dirt layers separating fractured formations and drinking water aquifers utilized for citizen consumption. Natural conditions of pressure and permeability help reduce the mitigation of contaminants, introduced by hydraulic fracturing, into fresh water sources. That being said, in a relatively new discussion, the well casings (Natural Gas Operations) near the surface of wells has offered a new perspective on fresh water safety. What is the failure rate of well casings drilled to date? What is the expected lifetime of the cement within well casings? They are not likely forever-lasting.
With the knowledge that there are natural blocks to groundwater contamination from fracturing one can begin to ask why there is so much media attention to groundwater contamination. Certain is the fact that not all well casings are flawless. Also certain is the fact that the disaster of the BP Horizon Oil Rig was at least partially caused by well casing failure. Another contributor to media attention is the disputed methane drinking water contamination.
An Introduction to Hydraulic Fracturing Misinformation 