Aug 10 2012
In this interview, Daniel Rozel talks about his work regarding water pollution associated with fracking and how this can be reduced.
Could you please give a brief introduction to what hydraulic fracturing (fracking) is, why it is a growing industry and where it is being undertaken?
The idea of creating new fractures in a geologic formation to enhance oil and gas recovery is not new. In the 1860s, during the early days of the first Pennsylvanian oil wells, nitroglycerin was exploded in wells in order to increase well productivity. Modern hydraulic fracturing was first performed in 1947 in Kansas by Stanolind Oil using highly pressurized napalm-thickened gasoline to stimulate a natural gas well. Fracturing using water-based gels started in 1953. Subsequently, the use of hydraulic fracturing increased at a steady pace, but has risen sharply in recent years due to a combination of market forces and improvements in the technology. The most notable improvement is the use of horizontal drilling along with multi-stage fracturing which allows for the economical extraction of natural gas from thin shale formations. The application of hydraulic fracturing to shale formations is the primary reason for the recent increase in natural gas production in the U.S. In 2000, shale gas accounted for 1% of U.S. natural gas supply; it reached 20% in 2010 and is projected to reach 50% by 2035 according to IHS CERA. Recently, the BP Energy Outlook for 2030 projected that natural gas production will be the largest energy growth sector over the next 20 years with shale gas specifically accounting for over 60% of North American production by 2030 and the region changing from a net energy importer to an exporter. The vast majority of fracking is taking place in the U.S. and Canada, however, China is aggressively pushing for investment in shale hydraulic fracturing technology and is expected to be the next frontier of the shale gas boom.
You have recently co-written a paper entitled “Water Pollution Risk Associated with Natural Gas Extraction from the Marcellus Shale”- who worked with you on this?
My co-author is Dr. Sheldon Reaven, a professor in the Dept. of Technology & Society at SUNY Stony Brook.
What was the primary aim of this study?
The risk of water contamination from hydraulic fracturing represents a fundamental uncertainty associated with the public policy debate of shale gas extraction. As a first step, we decided to complete a risk analysis of water contamination in order to make a useful contribution to the debate.
Where was your area of study for this analysis? Is this a representative location for the fracking industry?
This study was limited to the Marcellus Shale region. The Marcellus Shale is the largest shale deposit in the US and serves as an exemplar for the policy issues that arise from natural gas extraction via hydraulic fracturing. Over the course of the study, it was determined that the Marcellus region is somewhat unique in that it has relatively few suitable sites for the deep well injection of fracking wastewaters. Thus, gas drillers are more reliant on industrial wastewater treatment plants and surface disposal. It turns out that this represents the largest risk of drinking water contamination.
Could you briefly explain your “probability bounds analysis” analytical approach?
Probability bounds analysis is a technique that can use both interval ranges of data and probability distributions to represent inputs into a model. The output is a bounded range of probabilities that generally encloses all the possible outputs that might be generated. These bounds, often thought of as best-case and worst-case probabilities, are useful because they can help researchers and policy-makers decide if more research in necessary in order to make a decision or if certain outcomes are even possible.
What is the potential harm to the general public from contaminated wastewater? What harmful chemicals does the wastewater generally contain? Is there a potential harm to local ecosystems and the environment?
Although it varies by local geology, wastewater that has come in contact with the Marcellus Shale is generally saltier than seawater, contains some heavy metals such as strontium, and has naturally occurring radioactive materials such as radium and radon. Levels of these contaminants can range from low to over one thousand times the federal drinking water standards. This study did not address the public health and environmental impacts of these contaminants, but prior studies indicate a clear concern.
What additional water safety steps would you recommend to hydraulic fracturing companies to ensure less water contamination?
I would suggest two priorities. First, ensure that wastewater is being treated so that any effluent released to surface waters complies with the Clean Water Act and Safe Drinking Water Act. Second, invest in technology research that reduces the amount of water used in the fracking process. Potential options are filtering technologies that increase the ability to reuse wastewater in subsequent wells and non-water fracking technologies such as gas fracking. There have even been suggestions that fracking with liquefied carbon dioxide would sequester greenhouse gases thereby lowering the carbon footprint of natural gas extraction.
Can fracking become environmentally sound if correct procedures are implemented?
This very much depends on how one defines “environmentally sound.” Compared to most renewable energy technologies, such as wind turbines, fracking will never be as environmentally benign. However, compared to current practices such as mountain-top removal for coal extraction or oil from tar sands, fracking is likely already a more environmentally-friendly technology. It is up to the public and policy-makers to decide what risks and costs are acceptable in future energy policy.
Where can we find your paper, “Water Pollution Risk Associated with Natural Gas Extraction from the Marcellus Shale”?
The paper has been published in the August 2012 issue of the journal Risk Analysis.
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