the cause of localized water pollution. For instance, industrial spills, agri-
cultural runoff, or untreated sewage runoff can contaminate rivers. Even
oceans can be subjected to large-scale pollution, due to garbage dumping
and oil spills. Oceans rich in animal and plant life cover more than 70% of
the earth. Protecting the earth from water pollution is essential to the
long-term survival of the human species. Water is also essential to main-
taining our quality of life. It takes an estimated 400 gallons of water to
produce 1 gallon of gasoline. 50,000 gallons of water are needed to
produce an automobile.
There are certain water pollutants specifically associated with the
power generation and transportation industries. These pollutants are oils,
hydrocarbons, and lead. See Figure 26-4. Another water pollution problem
that is a direct result of burning fossil fuels is acid rain.
Acid rain forms when water vapor and certain elements combine
chemically with natural and human-made pollutants in the stratosphere.
Emissions, such as sulfur dioxide and nitrogen oxide, combine with water
vapor in the air to form sulfuric and nitric acids. When this mixture
combines with rain and falls back to earth, it can contaminate lakes, rivers,
and streams. Acid rain can make these bodies of water more acidic than
they would be naturally. The subsequent effects can be detrimental to
plant and animal life. Acid rain is also known to leach natural aluminum
from the soil. This aluminum is extremely toxic to many organisms, such
as plants that exist in the water.
It is estimated that natural pollutants, such as acid rain and smog
created as the result of wildfires caused by lightning strikes, account for
only about 10% of all the acid rain on the planet. The remaining 90% is
estimated to be occurring as a result of the combustion of fossil fuels. This
problem was first noticed around the beginning of the Industrial
Revolution in the late eighteenth century. At that time, fish kills in ponds
located close to industrial plants were reported. A fish kill results in the
death of a large number of fish, due to a rapid change in the characteris-
tics of their environment. The change could be a severe temperature
change in a short period of time or a severe change in the toxicity of the
water. The solution of the Industrial Revolution era was to build taller
smokestacks so the waste would be dispersed over a larger area.
The pH of a solution is a measure of its acidity. The pH scale consists
of a range from 0 to 14. A 7 on the pH scale represents a perfectly neutral
solution. Acidic solutions have a pH rating of less than 7. A rating above 7
Natural pollutant:
Something
produced by
nature that
contaminates the
environment.
Fish kill: The death
of a large number
of fish, due to a
rapid change in the
characteristics of
their environment.
pH: A measure of a
solution’s acidity.
Acidic solution:
A solution with a
pH rating of less
than 7.
Energy, Power, Transportation, and the Environment 615
Pollutant Source Effects
Oils and Oil spills, oil leaks, Death of fish, disruption of food
hydrocarbons oil field run-off chain, contamination of drinking
water, possible liver and kidney
damage from eating
contaminated fish
Lead Some hydrocarbon fuels Lead poisoning
Figure 26-4. Water pollutants associated with transportation and power
generation.
G R E E N T E C H
The Deepwater
Horizon oil spill in
2010 caused
damage to the
environment and
animal life in the Gulf
of Mexico. It took
three months to stop
the oil leak, after
which oil was still
found in the
surrounding area.