Water pollution is the
introduction into fresh or ocean waters of chemical, physical, or biological
material that degrades the quality of the water and affects the organisms living
in it. This process ranges from simple addition of dissolved or suspended solids
to discharge of the most insidious and persistent toxic pollutants (such as
pesticides, heavy metals, and nondegradable, bioaccumulative, chemical
compounds).
Water pollution occurs when a
body of water is adversely affected due to the addition of large amounts of
materials to the water. When it is unfit for its intended use, water is
considered polluted. Two types of water pollutants exist; point source and
nonpoint source. Point sources of pollution occur when harmful substances are
emitted directly into a body of water. The Exxon Valdez oil spill best
illustrates a point source water pollution.
Oil
Slick from the Exxon Valdez
Photo
courtesy of the Exxon Valdez Oil Spill Trustee Council
A nonpoint source delivers
pollutants indirectly through environmental changes. An example of this type of
water pollution is when fertilizer from a field is carried into a stream by
rain, in the form of run-off which in turn effects aquatic life.
Eutrophication
Eutrophication is a process
whereby water bodies, such as lakes, estuaries, or slow-moving streams receive
excess nutrients that stimulate excessive plant growth (algae, periphyton
attached algae, and nuisance plants weeds). This enhanced plant growth, often
called an algal bloom, reduces dissolved oxygen in the water when dead plant
material decomposes and can cause other organisms to die. Nutrients can come
from many sources, such as fertilizers applied to agricultural fields, golf
courses, and suburban lawns; deposition of nitrogen from the atmosphere; erosion
of soil containing nutrients; and sewage treatment plant discharges. Water with
a low concentration of dissolved oxygen is called hypoxic. More Information
Examples of Water Pollution
Industrial Pollution
Water is discharged
from after having been used in production processes. This waste water may
contain acids, alkalis, salts, poisons, oils and in some cases harmful
bacteria.
Mining and Agricultural Wastes
Mines, especially
gold and coal mines, are responsible for large quantities of acid water.
Agricultural pesticides, fertilizers and herbicides may wash into rivers and
stagnant water bodies.
Sewage Disposal and Domestic
Wastes
Sewage as well as
domestic and farm wastes were often allowed to pollute rivers and dams.
Water pollution is a serious
global Problem. It is the leading worldwide cause of deaths and diseases
and that it accounts for the deaths of more than 14,000 people daily.
Data
compiled from The British Antarctic Study, NASA, Environment Canada,
UNEP, EPA and other sources as stated and credited Researched
by Charles Welch-Updated dailyThis Website is a project of the The
Ozone Hole Inc. a 501(c)(3) Nonprofit Organization
