When compared to other procedures, fracking uses relatively small amount of water
Hydraulic fracturing has unleashed a renaissance of oil and gas production in the United States.
The chart below shows American oil and gas production from 1970 to 2014. After more than three decades of declining production, the adoption of fracturing in the mid to late 2000s has led to considerable production growth. Specifically, since 2005 U.S. oil production has grown by 68 per cent and gas production has grown by 43 per cent.
But hydraulic fracturing has proved to be controversial, and in the battle over whether to continue to use this technique, water consumption is often singled out by opponents of fracturing as a reason for bans or restrictions.
But a new study in the journal Environmental Science & Technology Letters by researchers at Duke University sheds some light on just how much water has been used by hydraulic fracturing in the U.S. This study is the most comprehensive and widespread estimation we have seen on water requirements for fracturing. The main conclusions of the study are:
• There are large variations in water use between different fields, with water use ranging from 13.7 to 23.8 million litres per well for shale gas and 1.3 to 15.1 million litres per well of unconventional oil.
• Between 2005 and 2014, water use for shale gas was three times larger than that for unconventional oil.
• Between 2012 and 2014, the annual estimated water use for combined shale gas and unconventional oil was 183 billion litres. This is 0.87 per cent of total industrial water use and 0.04 per cent of total fresh water use in the U.S. per year.
• The water use intensity (WUI) was estimated to range from 0.7 to 9.3 litres per gigajoule (L/GJ) for shale gas and 1.1 to 7.5 L/GJ for unconventional oil. These values are higher than those associated with conventional oil and gas extraction (approximately 0.7 L/GJ). Although conventional oil extracted using enhanced oil recovery techniques can have a much higher WUI of 120 L/GJ. Shale gas and unconventional oil have much lower WUI values for extraction when compared with coal (underground mine, 28.4 L/GJ; surface mine, 3.2 L/GJ) and uranium (23.8 L/GJ).
Two things in particular stand out to us from the study. The first is the stark differences in water requirements between different products and basins—something that has been found in other examinations of the potential environmental impacts from hydraulic fracturing. These realties mean that regulations will be best suited for the provincial or state level, as these units of government will best be able to deal with the unique challenges that each basin’s geology presents.
The second thing that stands out is that the water used by hydraulic fracturing represents a very small share of all water used for industrial and other purposes in the U.S. Without the proper context, the amounts of water required for hydraulic fracturing can seem large and daunting. When it’s compared to the amount of water required for other uses, however, the amount required for fracturing appears to actually be rather small.
This percentage may continue to fall, as growing amounts of water used in hydraulic fracturing are being recycled. Prior to 2011, only 13 per cent of waste water was recycled in the Marcellus, but by 2011 that number had risen to 56 per cent and more recently, in some circumstances, waste water recycling is approaching 90 per cent.
In the larger debates over fracking, context matters. As seen in the study referenced above, yes, fracking uses large volumes of water. But this water use is quite small in the grand scheme of things. A little more context may go a long way to showing that hydraulic fracturing is far from the disaster that opponents claim.