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Oil & gas
Oil and gas explorations use large
amounts of water for well drilling, site
development, and fracturing.
Water contamination is a significant risk
when oil and gas operations intersect
with drinking water supplies, or is
transported via long pipelines, which are
difficult to monitor, in the case of uncontrolled
spills or wastewater discharge or
through unconventional forms of natural
gas extraction, like coal-bed methane, oil
sands, and shale gas.
Pumping oil and gas out of the ground
produces large volumes of low-quality
water known as “produced water.” The
movement and disposal of this heavily
polluted water is a part of the debate on
the environmental impact of oil and gas
extraction.
Oil refineries are often situated near
navigable rivers, lakes, or seaports for
transport reasons. Low water levels
increase costs for shipping oil and gas.
Coal & ore mining
Many mining operations extract ore from
below the water table, which can affect
local hydrology and ecosystems.
Acid runoff affects water quality by
reducing pH levels and increasing
concentrations of toxic or heavy metals
like copper, lead, and mercury in mine
drainage water.
Spills of coal sludge or cyanide can
severely affect freshwater resources.
Closed mines can pose long-term
environmental liabilities as they must
be pumped and treated indefinitely to
prevent contamination of surface and
ground water.
Figure 7. Extractives sector impacts on water 60
Extractive industries are often considered strategic national industries with
privileged access to government, but their negative impacts on local water resources
can bring political heat and therefore increase pressure on water rights
and prices and on the license to operate. Recent oil spills, such as the 2010
Deepwater Horizon accident, contribute to the global oil industry’s negative
image and have forced the industry to reconsider its security and environmental
policies.
To separate each litre
of oil from tar sands,
4-5 litres of water are
needed.
Water facts and the extractives sector
»To refine 1 litre of oil, 2.5 litres of water are needed for processing and cooling.
»To separate each litre of oil from tar sands, 4–5 litres of water are needed.
»To » drill and fracture a typical shale gas well (depending on the basin and geological
formation), 20 million litres of water are required 61 .
»To » extract 1 kilogram of ore (depending on the ore type), 0.1–80 litres of water are
needed.
»The » estimated cost to clean up polluted drainage from years of coal mining in West
Virginia is €4–12 billion.
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