Ground Water Contamination
Ground water contamination usually arises when individuals have
wells. In those circumstances, the ground aquifer is contaminated
with the specific chemical or chemicals released by the responsible
party. This material then develops into a plume and infiltrates
the various well water sources. Individuals who own the wells
are then exposed to the chemicals by ingestion (drinking the
water), skin contact (bathing with the water) and inhalation
(breathing steam from the water).
In addition to being exposed to ground water contamination through
direct contact with well water, people in areas with a high water
table can be exposed to groundwater contamination from the air
in their home. If the chemicals are volatile, such as gasoline
or other materials, they may escape into a person's basement
and may be trapped, thereby exposing the home-owner who may inhale
the fumes.
Surface Water Contamination
What kind of contamination is it?
Surface water is usually rain water that collects in surface
water bodies, like oceans, lakes, or streams. Another source
of surface water is groundwater that discharges to the surface
from springs. Surface water pollution occurs when hazardous substances
come into contact and either dissolve or physically mix with
the water. Because of the close relationship between sediments
and surface water, contaminated sediments are often considered
part of surface water contamination. Sediments include the sand
and soils on the bottom of an ocean, lake, or stream.
How did it get there?
Surface water can become contaminated in many ways. Surface
water can be contaminated when hazardous substances are discharged
directly from an outfall pipe or channel or when they receive
contaminated storm water runoff. Direct discharges can come from
industrial sources or from certain older sewer systems that overflow
during wet weather. Storm water runoff becomes contaminated when
rain water comes into contact with contaminated soil and either
dissolves the contamination or carries contaminated soil particles.
Surface water can also be contaminated when contaminated groundwater
reaches the surface through a spring, or when contaminants in
the air are deposited on the surface water. Contaminated soil
particles carried by storm water runoff or contaminants from
the air can sink to the bottom of a surface water body, mix with
the sediment, and remain.
How does it hurt animals, plants and humans?
A change in the water chemistry due to surface water contamination
can negatively affect all levels of an ecosystem. It can impact
the health of lower food chain organisms and, consequently, the
availability of the food supply up through the food chain. It
can also impact the health of wetlands and impair their ability
to support healthy ecosystems, control flooding, and filter pollutants
from storm water runoff. Contaminated surface water can also
affect the health of animals and humans when they drink or bathe
in contaminated water or, for aquatic organisms, when they ingest
contaminated sediments. One of the major concerns associated
with contaminated surface water is the ability of aquatic organisms,
like fish, to accumulate and concentrate contaminants in their
bodies. When other animals or humans ingest these organisms,
they receive a much higher dose of contamination than they would
have if they had been directly exposed to the original source
of the contamination.
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