Transcript File - Ms. D. Science CGPA

Land, Air, and Water Resources
Ms. De Los Rios
7th Grade
8-4 Water Pollution and Solutions
Essential Question:
How Do People use Earth’s Resource?
Why is Fresh Water a Limited Source?
What are the Major Sources of Water Pollution?
How can Water Pollution Be Reduced?
Pgs. 280-287
Vocabulary
Pesticide- A chemical that kills
insects and other crop-destroying
organisms.
Sewage- The water and human
wastes that are washed down
sinks, toilets, and showers.
Sediment- small, solid pieces of
material that come from rocks
or the remains of organisms;
earth materials deposited by
erosion.
My Planet Diary- pg. 280
A Flood of Sludge
In December 2008, over 4.5 billion liters of polluted water flooded the
area around Kingston, Tennessee. A nearby coal-powered electric
plant produced polluted water containing arsenic, lead, and other
toxic chemicals. The toxic chemicals and coal ash mixed with water
in a holding pond to form a thick sludge. When the dam holding back
the pond broke, the water poured into rivers. The sludge water spilled
over the land, damaging trees, homes, and other buildings. Local
residents feared the flood would be dangerous to their health as well.
Communicate- Is water pollution a problem in your community? Why
or why not? ____________________________________________
_______________________________________________________
_______________________________________________________
Why Is Fresh Water a Limited Resource? Pg. 280
•Oceans cover nearly three fourths of the Earth’s surface.
Yet water is scarce on Earth because
most of it—about 97 percent—is salt water.
•Salt water cannot be used for drinking or watering crops.
About three quarters of the planet’s fresh water is ice. For
drinking water, people use fresh liquid water and
groundwater, which is water stored in soil and rock
beneath Earth’s surface.
Water is renewable: It cycles between the atmosphere and
Earth’s surface. Water shortages occur when people in an
area use water faster than the water cycle can replace it.
Assess Your Understanding pg. 281
I get it! Now I know that fresh water is limited on Earth
because____________________________________________
___________________________________________________
What are the Major Sources of Water Pollution?
Pg. 282
Since fresh water is scarce, water pollution can
be devastating.
Most water pollution is the result of human
activities. Wastes produced by agriculture, households,
industry, mining, and other human activities can end up in
water.
AGRICULTURAL WASTE
Agricultural wastes include animal wastes, fertilizers, and
pesticides, chemicals that kill crop-destroying organisms.
HOUSEHOLD SEWAGE
The water and human wastes that are washed down sinks, showers,
and toilets are called sewage. Sewage must be treated to kill
disease-causing organisms.
Farm Pollution
This scene may show common things found on a farm,
but even common things can lead to water pollution.
Circle the potential sources of water pollution.
What are the Major Sources of Water Pollution?
Pg. 282
INDUSTRY AND MINING WASTES
Industries and mines produce chemicals and metal wastes that
pollute water.
HEAT
Some factories and power plants also produce thermal pollution,
releasing heated water that can kill organisms living in bodies of
water.
OIL AND GASOLINE
Spills and leaks of oil and gasoline can cause catastrophic damage
to living things in water.
SEDIMENTS
Water that causes erosion picks up sediments, or particles of rock
and sand. In bodies of water, sediments can prevent plants from
growing by blocking sunlight.
Water Pollution Sources
What are the various causes of water pollution? Fill in the graphic organizer below
to outline causes of water pollution.
Assess Your Understanding pg. 253
I get it! Now I know that the major sources of water pollution
include _____________________________________________
___________________________________________________
How Can Water Pollution Be Reduced? Pg. 284
•By working together, governments, industries, and individuals can
improve water quality.
The keys to keeping water clean are effective
cleanup of oil and gasoline spills, proper sewage
treatment, and reduction of pollutants.
Cleaning Up Oil and Gasoline Spills
While natural bacteria can clean up small amounts of oil in bodies of
water, it is necessary for people to help clean up large spills.
Gasoline or oil leaks from underground tanks is hard to clean up.
Wastewater Treatment pg. 284
There are several steps to proper sewage treatment. What is the correct
order of proper sewage treatment steps?
How Can Water Pollution Be Reduced? Pg. 284
Sewage Treatment
In most communities, wastewater and sewage are treated before
they are returned to the environment.
Reducing Pollutants
Many industrial companies are trying to reduce the amount of waste
they produce, as well as to recycle wastes.
What You Can Do
Individuals can take steps at home to avoid creating water pollution.
Analyze Costs and Benefits pg. 285
What are the pros and cons of using bacteria to clean oil spills?
1.Fill in the boxes with some pros and cons of using engineered bacteria to
clean oil spills.
2. If you were creating bacteria for cleaning oil spills, what characteristics
would you want to test the bacteria for?
__________________________________________________________________
__________________________________________________________________
Fig. 4 How do people use Earth’s Resources?
Pg. 286
All living things depend on land, air, and water. Conserving
these resources for the future is important. Part of resources for the
future is important. Part of resource conservation is identifying and
limiting sources of pollution.
Land- Identify one impact humans have had on land. Then describe
one way to reduce pollution on land.
______________________________________________________
______________________________________________________
Air- Identify one impact humans have had on the air. Then describe
one way to reduce air pollution.
______________________________________________________
______________________________________________________
Water- Identify one impact humans have had on water. Then
describe one way to reduce water pollution.
______________________________________________________
______________________________________________________
Assess Your Understanding pg. 286
1a. What are sediments? _________________________________
______________________________________________________
b. How can bacteria help clean an oil spill in the ocean? _________
______________________________________________________
c. How do people sue Earth’s resources? ____________________
_____________________________________________________
d. Why might a company not want to recycle the waste they
produce even if it would reduce water pollution?________________
______________________________________________________
I get it! Now I know that water pollution can be reduced by ______
_____________________________________________________