protecting the water supply

saving water at home

Its easy to save water at home. If you save even a few gallons a day you can make a big difference over the long run. The best place to start saving water is in the bathroom. Toilet flushing is the single biggest use of water in the home. Showers and baths are the next biggest use. Follow the tips below to save water at home. Install water-saving toilets. They use only about half as much water per flush. A single household can save up to 20,000 gallons a year with this change alone! Take shorter showers. You can get just as clean in 5 minutes as you can in 10. And youll save up to 50 gallons of water each time you shower. Thats thousands of gallons each year. Use low-flow shower heads. They use about half as much water as regular shower heads. They save thousands of gallons of water. Fix leaky shower heads and faucets. All those drips really add up. At one drip per second, more than 6,000 gallons go down the drain in a year per faucet! Dont leave the water running while you brush your teeth. You could save as much as 10 gallons each time you brush. That could add up to 10,000 gallons in a year. Landscape your home with plants that need little water. This could result in a huge savings in water use. Look at the garden in Figure 21.20. It shows that you dont have to sacrifice beauty to save water.

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conserving water

Conserving water means using less of it. Of course, this mostly applies to people in the wealthy nations that have the most water and also waste the most.

water treatment

Water treatment is a series of processes that remove unwanted substances from water. The goal of water treatment is to make the water safe to return to the natural environment or to the human water supply. Treating water for other purposes may not include all the same steps. Thats because water used in agriculture or industry may not have to be as clean as drinking water. You can see how water for drinking is treated in Figure 21.18. Treating drinking water requires at least four processes: 1. Chemicals are added to untreated water. They cause solids in the water to clump together. This is called coagulation. 2. The water is moved to tanks. The clumped solids sink to the bottom of the water. This is called sedimentation. 3. The water is passed through filters that remove smaller particles from the water. This is called filtration. 4. Chlorine is added to the water to kill bacteria and other microbes. This is called disinfection. Finally, the water is pure enough to drink.

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rationing water

Some communities save water with rationing. Much rationing takes place only during times of drought. During rationing, water may not be used for certain things. For example, communities may ban lawn watering and car washing. People may be fined if they use water in these ways. You can do your part. Follow any bans where you live.

saving water in irrigation

Irrigation is the single biggest use of water. Overhead irrigation wastes a lot of water. Drip irrigation wastes a lot less. Figure 21.19 shows a drip irrigation system. Water pipes run over the surface of the ground. Tiny holes in the pipes are placed close to each plant. Water slowly drips out of the holes and soaks into the soil around the plants. Very little of the water evaporates or runs off the ground.

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reducing water pollution

In the mid 1900s, people were startled to see the Cuyahoga River in Cleveland, Ohio, burst into flames! The river was so polluted with oil and other industrial wastes that it was flammable. Nothing could live in it. You can see the Cuyahoga River in Figure 21.16

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what you can do

Most water pollution comes from industry, agriculture, and municipal sources. Homes are part of the municipal source and the individuals and families that live in them can pollute the water supply. What can you do to reduce water pollution? Read the tips below. Properly dispose of motor oil and household chemicals. Never pour them down the drain. Also, dont let them spill on the ground. This keeps them out of storm sewers and bodies of water. Use fewer lawn and garden chemicals. Use natural products instead. For example, use compost instead of fertilizer. Or grow plants that can thrive on their own without any extra help. Repair engine oil leaks right away. A steady drip of oil from an engine can quickly add up to gallons. When the oil washes off driveways and streets it can end up in storm drains and pollute the water supply. Dont let pet litter or pet wastes get into the water supply (see Figure 21.17). The nitrogen they contain can cause overgrowth of algae. The wastes may also contain bacteria and other causes of disease.

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controlling water pollution

Disasters such as rivers burning led to new U.S. laws to protect the water. For example, the Environmental Protection Agency (EPA) was established, and the Clean Water Act was passed. Now, water is routinely tested. Pollution is tracked to its source, and polluters are forced to fix the problem and clean up the pollution. They are also fined. These consequences have led industries, agriculture, and communities to pollute the water much less than before.

instructional diagrams

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questions

Passage of the Clean Water Act

-->  a. established the Environmental Protection Agency

b. outlawed emitting all pollutants into water

c. made governments responsible for all pollution

d. all of these

A burning river helped people realize the need to protect water.

-->  a. true

b. false

Water pollution has been reduced by laws fining polluters.

-->  a. true

b. false

Contaminants in water that need to be treated include

a. bacteria, algae, viruses, and fungi

b. some elements

c. chemical pollutants

-->  d. all of these

Most water pollution is caused by recreation on the water.

a. true

-->  b. false

Water purification

a. increases acidity

-->  b. does not always produce water that is safe for drinking

c. removes all contaminants

d. none of these

What can governments and international agencies do to prevent pollution and clean up the oceans?

a. pass laws

b. provide funding

c. enforce laws

-->  d. all of the above

Coagulation is used during water treatment to remove chemicals from water.

a. true

-->  b. false

Filters are used during water treatment to remove bacteria from water.

a. true

-->  b. false

To discard motor oil

a. put it in the storm sewers

b. put it down the drain

-->  c. take it to an approved disposal facility

d. put it on the ground

People in wealthy nations waste more water than people in poor nations.

-->  a. true

b. false

The single biggest use of water is for industry.

a. true

-->  b. false

Water-saving toilets use only about half as much water as regular toilets.

-->  a. true

b. false

When communities ration water, they ban its use by certain households.

a. true

-->  b. false

Chemicals are added to untreated water to cause solids to clump together.

-->  a. true

b. false

Cleaning the ocean of pollutants is difficult because the ocean is so vast.

-->  a. true

b. false

To protect the water supply, you should dispose of motor oil by

a. pouring it down the drain.

b. spreading it over the ground.

c. letting it run into a storm sewer.

-->  d. none of the above

It is easier to clean water that has become polluted than to keep it from becoming polluted.

a. true

-->  b. false

If pet wastes pollute the water supply, they can

a. add nitrogen to the water.

b. cause overgrowth of algae.

c. pollute the water with bacteria.

-->  d. all of the above

Water for drinking, medicine, agriculture, and water parks is all purified to the same quality.

a. true

-->  b. false

The goal of all water treatment is to

a. make water pure enough to drink.

-->  b. remove unwanted substances from water.

c. make water safe enough to return to the natural environment.

d. all of the above

Which processes are involved in treating drinking water?

a. coagulation

b. sedimentation

c. filtration

-->  d. all of the above

Wastewater contains hundreds of contaminants.

-->  a. true

b. false

In a wastewater treatment plant, water is treated in one single process.

a. true

-->  b. false

Ways that people can conserve water include all of the following except

a. fixing leaky faucets.

b. taking shorter showers.

c. using low-flow shower heads.

-->  d. leaving on the water while brushing teeth.

The single biggest use of water in the home is

-->  a. toilet flushing.

b. cooking.

c. cleaning.

d. laundry.

process in water treatment in which small particles are separated from water

a. water treatment

b. pollution

c. conservation

d. sedimentation

-->  e. filtration

f. coagulation

g. disinfection

process in water treatment in which large particles settle to the bottom of the water

a. water treatment

b. pollution

c. conservation

-->  d. sedimentation

e. filtration

f. coagulation

g. disinfection

series of processes to improve the quality of water

-->  a. water treatment

b. pollution

c. conservation

d. sedimentation

e. filtration

f. coagulation

g. disinfection

process in water treatment in which chlorine is added to water

a. water treatment

b. pollution

c. conservation

d. sedimentation

e. filtration

f. coagulation

-->  g. disinfection

preserving a resource by using less of it

a. water treatment

b. pollution

-->  c. conservation

d. sedimentation

e. filtration

f. coagulation

g. disinfection

contamination with chemicals, waste, or other harmful substances

a. water treatment

-->  b. pollution

c. conservation

d. sedimentation

e. filtration

f. coagulation

g. disinfection

process in water treatment in which solids in water clump together

a. water treatment

b. pollution

c. conservation

d. sedimentation

e. filtration

-->  f. coagulation

g. disinfection

diagram questions

No diagram questions associated with this lesson