Page 402 - Fundamentals of Gas Shale Reservoirs

382 GAS SHALE ENVIRONMENTAL ISSUES AND CHALLENGES

says, to the water use in 40–80 cities with populations of western states: Wyoming, Colorado, Montana, and North
50,000 people, or one to two cities with a population of 2.5 Dakota (Western Organization of Research Councils, 2013).
million each. In the Marcellus formation in Pennsylvania, Water use for fracking will remain a serious issue in the
New York, and West Virginia, water usage for well fracking parts of the country where significant oil and gas shale
could reach 650 million barrels per year according to a report development is taking place in drought stressed areas or
done by All Consulting for the U.S. Department of Energy areas traditionally facing water restraints. The February
(DOE) and state authorities (Arthur et al., 2010). 2014 Ceres report found that more than half of the wells—
When compared to the other water uses in the Marcellus 55%—were in drought‐stricken areas, and nearly half were
Basin, shale development is a fraction of total water usage in regions under high or extremely high water stress. Even in
for agricultural, industrial, and recreational purposes. For areas with adequate water supplies, better water management
example, the total volume of water needed to meet estimated will be necessary to reduce amounts of fracking wastewater,
peak shale gas development represents about 0.8% of the the disposal of which creates its own set of environmental
85 billion barrels (there are 42 gallons in a barrel) per year problems.
that are currently consumed in the region.
A University of Texas at Austin Bureau of Economic
Geology (BEG) study found that total water use for fracking 18.3 THE DISPOSAL AND REUSE
in Texas has risen by about 125%, from 36,000 acre‐ft in OF FRACKING WASTEWATER
2008 to about 81,500 acre‐ft in 2011 (Nicot and Scanlon,
2012). For a comparison, the 800,000‐person city of Austin With each round of fracking, about half of the fracking
used about 107,000 acre‐ft of water in 2011. About one‐fifth fluid, now called wastewater or flowback, returns to the sur-
of the current total water used in Texas comes from recycled face along with the gas, via the collection pipes. Although
or brackish water, a category of water supply that has been fracking fluids are more than 99% water and sand, they also
growing (Kalaswad et al., 2012). Water use for fracking is contain a number of chemicals, including some that are
not expected to exceed 2% of the statewide total water use. toxic at the parts‐per‐billion level. These include benzene,
But drilling can send water use percentages much higher antimicrobial agents, and corrosion inhibitors. The U.S.
in rural areas and aggregate numbers for use hide important House Energy and Commerce Committee released a report
conflicts in places where farmers compete with natural gas in April 2011 that identified 29 chemicals that are either
developers for their water supply, especially in drought known or possible carcinogens that would be normally sub-
stricken areas or areas traditionally with low rainfall. In ject to EPA regulation under the Clean Water Act. Oil and
these areas, fracking is driving up the price of water and gas fracking, however, was exempted from the act in 2005
burdening already depleted aquifers and rivers. (Chemicals, 2011).
A comprehensive May 21, 2013, report by Ceres, a Many environmentalists have severely criticized the
Boston‐based nonprofit organization, stated that 47% of oil handling of wastewater, claiming it results in toxic waste and
and gas fracking sites are in high or extremely high water‐ surface water contamination. A key problem is the disposal
stressed water basins (Freyman and Salmon, 2013). The of the increasing amounts of fracking fluid. As described in
study was based on water consumption by 25,450 fracking the Vaughn and Purcell study Frac Attack: Risks, Hype, and
wells that drillers voluntarily reported to the FracFocus, an Financial Reality of Hydraulic Fracturing in the Shale
industry run database, between January 2011 and September Plays, fracking chemicals and drilling waste are more haz-
2012. The data was then laid on top of water risk maps devel- ardous above ground than several miles underground and
oped by the World Resources Institute (WRI). According to pose a more serious environmental hazard than potential
the report, during the study period, U.S. fracking operations contamination of groundwater from fracking (Vaughan and
consumed 68.5 billion gallons of water—equivalent to the Pursell, 2010).
amount 2.5 million people would use in a year. Ceres For a producer, there are four options to handle waste-
researchers believe this figure is most likely an underesti- water: storage in tanks or tarp lined pits where the waste-
mate—oil and gas companies are not required to report how water is allowed to evaporate or be recycled, disposal in deep
much water they are using. A second Ceres report in February underground injection wells, trucking to publicly owned
2014, Hydraulic Fracturing & Water Stress: Water Demand treatment plants that may or may not be designed to handle
by the Numbers (Freyman, 2014), provides first‐of‐its‐kind fracking chemicals, or trucking to centralized waste
data on the various water sourcing risks facing oil and gas treatment facilities some of which can safely recycle the
companies in eight regions of intense shale development in water. Closed tanks are also sometimes used for collection of
the United States and Canada. An April 2013 report by the produced water during the flowback period, sometimes with
Western Organization of Resource Councils, a regional net- secondary containment. Open impoundments, also called
work of grassroots community organizations, found that pits, are typically subject to requirements designed to mini-
fracking is using 7 billion gallons of water a year in four mize the risk of contamination. As with any liquid material