How Our Water Becomes Polluted

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Unit 7: How Our Water Becomes Polluted

Words to Remember
Background Information
Questions for Review
Questions for Thought
Figure 7.1: Nonpoint Sources Of Pollution
Figure 7.2: The Flint Creek Watershed
Fact Sheet: How Our Water Becomes Polluted
Glossary: How Our Water Becomes Polluted
Worksheet 7.1: Definitions
Worksheet 7.2: Vocabulary (Puzzle)
Worksheet 7.3: Facts About How Our Water Becomes Polluted
Activity 7.1: Monitoring A Neighborhood Stream
Stream Quality Report Form
Activity 7.2: How Acidic Is It?
Activity 7.3: Effects of Pollution on Plants
Activity 7.4: Alternative Household Products
Activity 7.5: Making a Model of a Watershed
Activity 7.6: Wetlands Outdoor Game
Answer Key: Worksheet 7.1
Answer Key: Worksheet 7.2
Answer Key: Worksheet 7.3
How Am I Doing?

Unit 7: How Our Water Becomes Polluted
Level B
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Unit 7: How Our Water Becomes Polluted
Objectives: Each student will be able to:
! List causes of water pollution
! Discuss how people contribute to water pollution
! Explain the concept of a watershed
Words to Remember:
• acid
• diversity
• nutrients
• sediment
• acid rain
• erosion
• PCBs
• solvent
• agriculture
• fertilizer
• pesticides
• Tennessee Valley
• algae
• habitat
• pH
• toxic
• aquatic
• invertebrate
• point source
• universal solvent
• Blackbelt
• landfill
• pollutants
• watershed
• contaminants
• lagoon
• radium
• wetlands
• crop rotation
• leach
• radon
• Wiregrass
• nonpoint source
• runoff

Causes of Water Pollution. There are
two primary causes of water pollution:
Background Information
nature and people. Actually, although
Water has many properties. One of its
pollutants and contaminants are generally
properties is its ability to dissolve many
used to mean the same thing, pollutants are
substances. Because of this property, water
usually thought of as contaminants or
is known as the universal solvent and is
impurities in water due to the activities of
seldom found pure in nature. In fact,
people. Contaminants are usually thought
natural waters may contain hundreds or
of as impurities in water caused by natural
even thousands of chemicals, and in some
cases, an equal number of biological life
Naturally occurring events such as
forms (such as microorganisms).
volcanic eruptions, landslides, floods and
All forms of life depend on water. Water
wild animal wastes, can produce polluting
helps to dissolve chemicals in foods, then it
materials. These pollutants can wash into
transports these chemicals to cells in our
lakes, rivers and other streams and damage
bodies. However, sometimes harmful
water quality.
substances can dissolve in water.
Groundwater can become contaminated
Substances that harm the quality of water
by the minerals it comes in contact with. A
are known as pollutants or contaminants.
natural source of groundwater pollution is a
Most contaminants in water do not cause
gas called radon. Radon comes from
problems because they are not toxic and are
certain types of rock which contain the
at such low amounts. However, some
element radium. Scientists believe radon is
substances which dissolve in water, even at
dangerous to people, so groundwater from
very low levels, can be harmful.
wells where minerals contain radium

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should be tested for radon. Special filters
Automobiles are very
on faucets can remove radon from water.
useful in our society but
However, people cause
they cause air and water
most water pollution. People
pollution. Internal
cause water pollution through
combustion engines from cars release
carelessness or lack of
dangerous gases into the air. Some of these
knowledge. Farms, factories,
gases react with water vapor to form acid.
automobiles and even our homes are
When this water vapor condenses it
potential sources of pollutants.
produces acid rain. This acidic water
Farmers, gardeners and homeowners use
harms aquatic life in lakes and can damage
fertilizers and pesticides on their crops,
trees and buildings.
gardens and lawns. Although fertilizers
People contribute to water pollution in
supply nutrients which are essential for
their homes. In fact, homeowners apply
healthy plant growth, the use of too much
more fertilizers and pesticides, per square
fertilizer can cause nutrients to wash into
foot, on their lawns and gardens than
streams and creeks. Surface waters
farmers apply to entire crop fields.
contaminated by too many nutrients may
Homeowners don't always properly dispose
contain large amounts of algae. Algae is
of poisonous wastes, either. Some wastes
necessary for aquatic life, but too much
may be thrown into ditches or the woods, or
algae can cause the water to turn green and
flushed down the drain. Even some of the
have a bad smell or taste. It may even kill
wastes that end up in landfills may leach
fish when it dies and rots in the water.
into water supplies. Septic systems that are
Bacteria that grow and eat the dead algae
not functioning properly also can
use up all the oxygen. If this happens, the
contaminate groundwater. All of these
fish die from a lack of oxygen.
things can contribute to water pollution.
Pesticides sprayed on crops help protect
Types of Water Pollution. There are two
the plants from diseases and bugs. Diseases
main types of water pollution: point source
and insects are especially a problem in the
and nonpoint source. Point source
humid climate of Alabama. If pesticides
pollution is any pollution that comes from a
weren't used, farmers, gardeners and others
particular spot or source. For example,
would have a hard time growing successful
when a factory dumps contaminated water
crops. But many pesticides are toxic, or
into a river, it is point source pollution.
poisonous. They may wash into streams or
Nonpoint source pollution comes from
soak too far into the ground. They may
widespread areas, not just a particular
harm aquatic life and pollute our drinking
point. It is not always easy to identify the
specific source of nonpoint pollution. It
Sometimes contaminated water from
may come from many individual places.
factories is dumped or washed into nearby
Stormwater can cause runoff (precipitation
waterways. Poisonous chemicals may also
that flows off the land) from urban areas
be spilled, poured on the ground, or buried
and farm fields. This runoff can carry
in landfills or other places. These
sediment, nutrients, pesticides and other
chemicals can leach, or soak, into the
chemicals from farms and cities. It can
groundwater, contaminating our water
travel a long way before entering a stream
or river. Acid rain is another example of
nonpoint sources of pollution. The causes

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of acid rain and the areas affected may be
We used to think that wetlands were
Nonpoint sources of pollution are harder
worthless areas. These lands are difficult to
to clean up because they come from a
use for buildings or for planting crops. Now
variety of sources over a large area. See
we realize that wetlands are very valuable.
Figure 7.1 for examples of nonpoint
They help to control possible pollution
sources pollution.
problems. Wetlands act as a natural filter
The Watershed. A watershed is the land
for water soaking into the ground. They
area that drains into a water system such as
function as a transition between an area of
a river, stream or lake. This land area may
land and a body of water. In this transition
contain many smaller rivers, streams and
zone, wetlands can trap sediment and
creeks. An example of a watershed in
pollutants, and help to break them down
Alabama is the Flint Creek Watershed in
before they run into surface waters.
northern Alabama (Figure 7.2). In this
Wetlands act as storage areas for storm
watershed, Flint Creek joins West Fork
water. They provide habitats for many fish
Creek; they both eventually flow into the
and other wildlife. Shrimp, fish, crabs,
Tennessee River. Smaller watersheds make
shorebirds and alligators are very
up larger watersheds. An example of a
dependent upon coastal wetlands for
large watershed is the Mississippi River
survival. Wetland
Watershed. This very large watershed
areas are common in
stretches from the Rockies to the
southern Alabama.
Appalachian Mountains. It contains many
In Alabama, there
rivers; these include the Missouri, Ohio,
are 3 million acres
Arkansas and Tennessee Rivers.
of wetlands and
Any land activity within a watershed can
marshes, including 118,000 acres of coastal
affect the water quality of its rivers and
streams. Most precipitation eventually
Water Pollution in Alabama. Water
either seeps into the groundwater or drains
quality in Alabama is generally good,
into surface waters before it evaporates or
especially when compared to some other
is transpired back into the atmosphere. The
states. However, the state does have
runoff into surface water can carry
pollution problems. Sediment (solid
polluting materials. These materials could
particles, such as soil, carried by water), is
be from farmland, woodland, urban areas,
the major source of water pollution
marinas, waste dump sites and landfills,
problems in Alabama. Large amounts of
construction sites or other land-disturbed
soil can wash into streams. This sediment
areas, or where oil on and other chemicals
can cause many problems. It fills up
have been spilled or used on streets and
streams and causes flooding, it covers
roadways. To find a nonpoint source of
habitat (an animal's home--including its
pollution, we often must examine the entire
food, water and shelter). It hurts aquatic life
watershed. Therefore, the understanding of
by blocking necessary sunlight. Also,
a watershed is very important.
sediment can carry other polluting materials
Wetlands. Wetlands are areas of land
with it. When the land is disturbed by
that are often covered by water. They may
construction, farming, or timber harvesting,
contain either salt water or fresh water.
it is more susceptible to erosion. When it
Swamps and marshes are examples of
rains, particularly in heavy storms, bare soil

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is eroded and runoff carries the sediment to
Remember, much of these products go
lakes and waterways. Because land areas
down the drain and end
devoted to agriculture are generally quite
up in a septic tank or at
large, these areas contribute the most
a wastewater treatment
erosion and sediment to water sources.
plant. We should
Nutrients from animal wastes and
properly dispose of
fertilizers, and pesticides or other chemicals
hazardous, or poisonous wastes. We need
can be attached to sediment that is eroded
to be careful when we apply fertilizer and
from farmland and other areas. Wherever
pesticides to our lawns. They may wash off
the sediment goes, these materials also go.
during a rain storm.
There are certain areas in Alabama
Factories are required to treat wastewater
where water quality has been affected by
before dumping it back into rivers.
excess nutrients. These areas are generally
(However, there is still some illegal
those that have a high concentration of
dumping). Emission control devices are
animals or agricultural crops. The
required on cars. These devices help reduce
Tennessee Valley in northern Alabama and
pollutants caused by exhaust which
the Wiregrass in the coastal plain of
contribute to acid rain pollution.
southeast Alabama have the greatest
Today, there are less toxic materials in
amounts of cropland. Cropland areas also
our waters than in the past. This decline is
have the most frequent pesticide pollution
due partly to the banned use of chemicals
problems. Because of Alabama's large
such as DDT and PCBs, and the decreasing
poultry industry, animal wastes pose
amount of coal mining in our state.
problems for water quality in certain areas.
Chemicals such as DDT and PCBs are
Another unique area in Alabama is the
toxic chemicals that were once used by
Black Belt region. This area in the west-
agriculture and industry. These chemicals,
central part of the state is named for its
particularly PCBs, have sometimes been
unusual black-colored soils. Sometimes the
found in rivers and streams and in the fish
water quality in this region is not very
found there. DDT and PCBs worked well
good, but it is because there is often a high
for each of their purposes, but they last a
mineral content in the water. This is a
very long time in the environment, so it is
naturally occurring contaminant due to the
hard to clean them up. They have been
nature of the soil and is not caused by any
linked to the decline in bald eagle
polluting activities of people.
populations (although this has not been
In Alabama, the most frequent causes of
proven). However, industries in Alabama
lake pollution are point sources from
which once used PCBs have spent large
industry and city wastewater. According to
amounts of money to help clean up the
the Alabama Department of Environmental
environment. Bald eagle populations are
Management, agricultural runoff causes
increasing in Alabama, partly due to a eagle
more nonpoint pollution in rivers and
sanctuary in Lake Guntersville State Park.
streams in our state than any other activity.
Farmers can help
Ways to Prevent Water Pollution. It is
erosion and
everyone's responsibility to care for our
runoff. There are many
environment and to help prevent water
management practices
pollution. In our homes, we can use less
called best management
harmful chemicals for cleaning products.
practices or BMPs, that farmers can use to

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reduce sediment, nutrient and pesticide

2. What causes most water pollution--
pollution. One method which helps protect
natural events and processes or people?
the land is the practice of crop rotation.
3. Name a way in which water can become
Less erosion occurs when types of crops
polluted in nature.
grown on farmlands are changed (or

4. List some ways in which people
rotated) periodically. This helps preserve
contribute towards water pollution.
nutrients and reduces the need for certain
5. What are the two main types of water
pesticides. It decreases the chance of
fertilizer and pesticides getting into water
6. Why is it harder to clean up pollution
supplies. Farm animals should be kept out
from nonpoint sources?
of nearby streams. This helps to keep
7. Why is it important to consider the
animal wastes out of our waterways.
entire watershed when looking for
Animal manures from confined animal
sources of pollution?
operations should be stored, handled and
8. What is a wetland? Why are wetlands
used so that they do not get into water
9. What is a major pollutant in Alabama's
One example in Alabama of everyone
water? Is this from a point or nonpoint
working together to improve water quality
is the Bear Creek Floatway Water Quality
10. What are some ways in which we can
Improvement Project. This waterway is
prevent water pollution?
near the Tennessee River in northwest
Alabama. It was once closed to recreation
Questions For Thought
because of pollution problems. Agricultural
pollutants from farm animals were the main
1. Do you think that it is always possible
sources. People worked together to identify
to recognize polluted water by its
and solve these pollution problems.
Federal, state and local agencies all
2. If you found a polluted stream or creek
contributed money to the efforts. Farmers
in your neighborhood, how do you
moved livestock away from streams and
think it could get cleaned up? Who
built fences to keep them out of the water.
would you let know?1
They built lagoons to store waste and
3. Many wetlands in our country were
capture runoff from animal waste products.
destroyed because people thought they
A special area was built to filter wastewater
had no value. What would be the results
from a local school system.
if we continue to destroy our wet-
Today, the Bear Creek Floatway is open
again to recreation. This cooperation be-
4. If you were a farmer in Alabama, what
tween people and all levels of government
could you do on your farm to help
shows, when we really try, we can protect a
prevent water supplies from getting
very valuable natural resource--Alabama's
Service Learning Idea:
Questions For Review
"Trash Patrol"
Form a clean-up crew of school
1. Why is water known as the universal
friends. Adopt an area within your com-
munity where litter is often dropped, such

Unit 7: How Our Water Becomes Polluted
Level B
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as a playground, city park, or an area by a
Teacher Notes:
stream. Once a week patrol the adopted
area and pick up trash. Litter can wash
1 You could contact your local Health
into waterways during rain storms and
Department if you think that the water is
become a cause of pollution.4
seriously contaminated.
2 The play "Willa in Wetlands" is available free of
charge from the E.P.A. This play could be
performed for a younger group of children at
your school. See resource list at the end of
3 Have a local farmer come to speak to your
class about procedures he uses on his farm and
what he does to help prevent water pollution.
4 Two programs in Alabama help to clean up
litter. These are Alabama PALS and Adopt-A-
Stream. For information on how your club can
join, contact (334) 263-7737.
Note: There are two models available for loan
which help demonstrate pollution:
the Enviroscape and the plexiglass
Groundwater Model. See Equipment and
in the Bibliography and Resource
Materials section for more information.

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Level B
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FIGURE 7.1: Nonpoint Sources Of Pollution

Urban runoff from garbage
dumped in streams
Runoff from croplands
Animal waste runoff
Stormwater runoff from pavement

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FIGURE 7.2: The Flint Creek Watershed

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FACT SHEET: How Our Water Becomes Polluted

Interesting facts to remember about how water becomes polluted:
1. Many substances can dissolve in water; this is why it is known as the universal
2. When harmful substances mix with water, this causes water pollution.
3. Natural events, such as volcanic eruptions, floods, landslides and even radon gas
from the ground, sometimes cause water pollution.
4. Most water pollution is caused by people.
5. People cause water pollution by the way they use land and water resources and how
they manage waste products. If fertilizers and pesticides are not used with care on
farms, gardens, and yards, they can leach into groundwater or wash into waterways.
6. Acid rain is caused when acidic gases (such as are produced by the internal
combustion engines of automobiles) mix with rain; it can harm aquatic life and trees
in forests. Smoke stacks from factories can also put acid-forming gases into the air.
7. There are two main types of water pollution: point sources and nonpoint sources.
8. Nonpoint source pollution is harder to clean up because it is transported in storm
water from a variety of locations.
9. Sometimes we must look at the entire watershed to find the source of water
10. Wetlands help protect water quality by filtering out pollutants.
11. Sediment from agricultural areas is a major water pollutant in Alabama.
12. Runoff of excessive sediment into surface water can damage lakes, rivers and other
13. It is everyone's responsibility to help prevent water pollution.

Document Outline
  • Unit 7: How Our Water Becomes Polluted
  • FIGURE 7.1: Nonpoint Sources Of Pollution
  • G
  • GLOSSARY: How Our Water Becomes Polluted
    • Puzzle B
  • Activity 7.1: Monitoring A Neighborhood Stream
  • ACTIVITY 7.3: Effects of Pollution on Aquatic Plants