Page 561 - Environment: The Science Behind the Stories

the United States was found to be far away from the nearest
city, in a little-populated region of Wyoming home to exten-
sive fracking operations.
Many residents of areas near hydraulic fracturing sites
have experienced polluted air and fouled drinking water
(pp. 180–182), but more research is needed to assess the extent
of such pollution and to quantify the health risks.
Hydrofracking also produces immense volumes of
wastewater. Injected water often returns to the surface laced
with salts, radioactive elements such as radium, and toxic
chemicals such as benzene that come from deep under-
ground. This wastewater is often sent to sewage treatment
plants that are not designed to handle all the contaminants
and that do not regularly test for radioactivity. This has
caused concern in Pennsylvania, where a boom in natural FIGURE 19.19 In mountaintop removal mining for coal, entire
gas extraction from the vast Marcellus Shale deposit con- mountain peaks are leveled and fill is dumped into adjacent
tinues to send millions of gallons of drilling waste to treat- valleys, as shown here over many square miles in West Virginia. This
ment plants, which then release their water into rivers that can cause erosion and acid drainage into waterways that flow into
supply drinking water for people in Pittsburgh, Harrisburg, surrounding valleys, affecting ecosystems and people over large areas.
and other cities.
Coal mining devastates natural systems

Oil sands development pollutes water The mining of coal exerts substantial impacts on natural
systems and human well-being (pp. 657–658). Strip mining
Similar concerns are being voiced about the extraction and destroys large swaths of habitat and causes extensive soil ero-
transport of oil from oil sands. People living along the route of sion. It also can cause chemical runoff into waterways through
the Keystone XL pipeline worry that if oil were to spill from a the process of acid drainage (pp. 657–658). This occurs when
leak in the pipeline, it would sink into the area’s porous ground sulfide minerals in newly exposed rock surfaces react with
and quickly reach the region’s shallow water table, contami- oxygen and rainwater to produce sulfuric acid. As the sul-
nating the Ogallala Aquifer. This aquifer (p. 411) provides 2 furic acid runs off, it leaches metals from the rocks, many
million Americans with drinking water and irrigates a large of which are toxic. Acid drainage is a natural phenomenon,
portion of U.S. agriculture. The pipeline was originally slated but mining greatly accelerates the rate at which it occurs by
to cross the Sandhills region of Nebraska, an ecologically exposing many new rock surfaces at once. Regulations in the
valuable area that hosts most of the world’s Sandhill cranes United States require mining companies to restore strip-mined
as well as other migratory birds. At the behest of government land following mining, but complete restoration is impossi-
regulators, TransCanada agreed to move the proposed route ble, and ecological modifications are severe and long-lasting
eastward to skirt around the edge of the Sandhills region and (pp. 661, 664). Most other nations exercise less oversight.
the Ogallala Aquifer. Mountaintop removal mining (FIGURE 19.19 and pp. 659–
Pipeline leaks are a legitimate concern, as oil from oil 663) has impacts that exceed even conventional strip mining.
sands is more corrosive than conventional crude oil. Recent When countless tons of rock and soil are removed from the top
leaks along the Kalamazoo River in Michigan, in a residential of a mountain, material slides downhill, where immense areas
neighborhood of Mayflower, Arkansas, and in other locations of habitat can be degraded or destroyed and creek beds can be
have caused severe contamination. clogged and polluted. Loosening of U.S. government regula-
In Alberta where the oil sands are mined, the process uses tions in 2002 enabled mining companies to legally dump moun-
immense amounts of water, and the polluted wastewater that taintop rock and soil into valleys and rivers below, regardless of
results is left to sit in gigantic reservoirs. The Syncrude com- the consequences for ecosystems, wildlife, and local residents.
pany’s massive tailings pond near Fort McMurray, Alberta, is
so large that it is held back by the world’s second-largest dam.
Migratory waterfowl land on water bodies like this and are Oil and gas extraction modify
killed as the oily water gums up their feathers and impairs the environment
their ability to insulate themselves. These water pollution
impacts come on top of the deforestation required to mine the To drill for conventional oil or gas on land, road networks
fuels in the first place. must be constructed and many sites may be explored in the
Industry representatives counter that the area defor- course of prospecting. The extensive infrastructure needed to
ested so far amounts to just 0.1% of Canada’s vast boreal support a full-scale drilling operation typically includes hous-
forest. They also point out they are mandated to attempt ing for workers, access roads, transport pipelines, and waste
restoration afterwards. However, effective reclamation has piles for removed soil. Ponds may be constructed to collect
not yet been demonstrated, and regions denuded by the very the toxic sludge that remains after the useful components of
first oil sand mine in Alberta 30 years ago have still not oil have been removed. These activities can pollute the soil,
560 recovered. air, and water, fragment habitats, and disturb wildlife. All

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