Drinking water supplies are typically drawn from either groundwater (wells and springs) or surface water (rivers and reservoirs). Residents’ health depends on the ability to protect these water sources from contamination.
Shale gas development (SGD) introduces several concerns regarding water use and contamination. SGD requires large quantities of water throughout the drilling process. It is estimated that, in order to frack a single well, between 1.5 million and 9.7 million gallons of water must be used. This water is usually taken from local water sources and trucked or piped to the well pad.
In areas with limited resources of fresh water, SGD may place an undue burden on communities by impacting the amount of water residents have access to for themselves or for their livestock. SGD may impact the quality of local waterways for recreation as well. Importantly, from a public health perspective, SGD processes can contaminate groundwater, making wells unusable and harming the health of families. When this happens, residents must find alternative sources of water for drinking, cooking, showering, and other uses. For some residents, this looks like employing water buffaloes or buying bottled water to meet their needs.
Image courtesy of Bob Donan
How Does SGD Contaminate Water?
The shale gas industry uses water to create hydraulic fracturing fluid (HFF) or frack fluid. Frack fluid is a mixture of water, chemical additives, and proppants (silica sand). HFF is then forced down the wellbore at a high pressure in order to fracture the shale. Some of the HFF returns to the surface along with naturally occurring materials from the earth that are carried by the frack fluid back to the surface.
In addition to the HFF, water that was trapped in the shale formation, known as produced water, is also brought to the surface. Produced water contains brine, radioactive materials, gases, and inorganic and organic compounds. The combination liquid of HFF and produced water is referred to as flowback water and is considered highly toxic.
All these processes increase the risk of water supply contamination in regions where SGD operates. Water contamination can also occur when wastewater is transported away from the site due to accidents, spills, and illegal dumping. Some contaminants can alter the taste, odor, or clarity of water, while others are more difficult to detect. Many contaminants are toxic, and many others have not been tested for human toxicity.
The risk of groundwater contamination is greater in locations involving the use of fracking fluid and the storage and transportation of fracking waste. Such locations include well pads, injection storage wells, landfills accepting shale gas waste, and transportation routes of materials and waste.
Image courtesy of A. Vengosh, et al., Environmental Science and Technology 48:8334
Should I Be Concerned About My Water?
If you live near shale gas facilities, your water may be at risk of contamination from toxic chemicals. You may be exposed by drinking contaminated water, by absorbing them through direct skin contact when showering, and by breathing in vapors and volatile organic compounds (VOCs) that are released from the water during use. Such exposure may result in short-term or acute symptoms such as nausea, rashes, and stomach pain as well as skin, eye, and nose irritation. If exposure is frequent or spread out over a long time, prolonged or chronic symptoms may result.
If your water comes from a private well, you should be particularly aware of water quality issues. Private well water quality is not regulated in the United States, and well owners are responsible for performing their own monitoring and testing.
Municipal water supplies may also be at risk of contamination from SGD. Like well water, municipal water can be contaminated by surface water discharges, insufficient treatment of contaminated wastewater, illegal dumping of wastewater, and leachate from landfills accepting shale gas waste. Contamination can also enter the air, soil, and water through byproducts created by reactions between hydraulic fracturing contaminants and disinfectants like chorine, which can be formed at drinking water treatment facilities.
Regardless of the type of water you use, it is vitally important to be aware of changes in your water so that you can take steps to avoid or mitigate exposure. For more information about water testing and protecting your health, visit the where to turn directory and protecting your health .
Private Drinking Water Wells, Environmental Protection Agency