Unit E Lesson E12
Completion requirements
Lesson E12: How Humans Use Water
Video Lesson
Humans depend on water both for survival and modern comforts. Watch this video to learn more about different ways that humans use water.
Lesson E12: How Humans Use Water
Figure E.4.12.1 – Sometimes humans contaminate water with pollutants.
Figure E.4.12.2 – Mercury is a dangerous water contaminant.
Figure E.4.12.3 – Storm sewer drains collect rainwater from streets.
Reading
and Materials for This Lesson
Science in Action 8
Reading: Pages 392–399
Materials:
No additional materials needed for this lesson.
Humans Pollute Water
Sometimes pollutants enter water used by humans. Some water pollutants are living organisms, like bacteria. Other water pollutants are chemicals.
Because water dissolves other substances so well, industrial factories frequently use water. For example, pulp and paper mills use chlorinated water to bleach paper. If the water from pulp and paper mills is not cleaned properly, toxic chemicals can enter waterways through wastewater.
Another source of chemical water pollution occurs through storm water sewer drains, which usually lead directly to lakes and rivers. Wastes from streets can wash down storm sewers into waterways. For this reason, chemicals like oil and paint should never be dumped down sewer drains. Even soap and detergents act as water pollutants, because they cause algae growth in waterways.
Farming and agriculture can also pollute the water. Fertilizers, pesticides, and animal wastes contaminate streams, lakes, or groundwater, causing a variety of problems including algal blooms in the waterways or illness in plants and animals.
Many chemicals are used to make products that improve our lives. However, we need to use chemicals carefully to avoid water contamination.
Sometimes pollutants enter water used by humans. Some water pollutants are living organisms, like bacteria. Other water pollutants are chemicals.
Because water dissolves other substances so well, industrial factories frequently use water. For example, pulp and paper mills use chlorinated water to bleach paper. If the water from pulp and paper mills is not cleaned properly, toxic chemicals can enter waterways through wastewater.
Another source of chemical water pollution occurs through storm water sewer drains, which usually lead directly to lakes and rivers. Wastes from streets can wash down storm sewers into waterways. For this reason, chemicals like oil and paint should never be dumped down sewer drains. Even soap and detergents act as water pollutants, because they cause algae growth in waterways.
Farming and agriculture can also pollute the water. Fertilizers, pesticides, and animal wastes contaminate streams, lakes, or groundwater, causing a variety of problems including algal blooms in the waterways or illness in plants and animals.
Many chemicals are used to make products that improve our lives. However, we need to use chemicals carefully to avoid water contamination.
Figure E.4.12.4 – Run-off from farms can contain harmful fertilizers, pesticides, or animal wastes.
Watch More
Water Pollutants
Watch this video to learn more about different types of water pollutants.
Watch this video to learn more about different types of water pollutants.
These two videos explain the negative effects of water pollution by a harmful chemical called mercury.
This video explains how runoff from agriculture and other sources causes algal blooms.
Figure E.4.12.5 – Hydroelectric dams generate electricity.
Figure E.4.12.6 – Hydroelectric power stations contain large spinning turbines.
Figure E.4.12.7 – Large amounts of water must be held back, and surrounding land flooded, for hydroelectric dams to work.
Dams
Large concrete dams are built on rivers. Some dams control river flow to prevent flooding. For example, Calgary’s Glenmore Dam controls water flow in the Elbow River. This dam was built to prevent flooding of homes and businesses located close to the river. The Glenmore Dam also created a lake that stores drinking water for Calgarians.
Dams can also store agricultural water during dry seasons. Water in a dam-created lake can be sent down irrigation canals to provide water for crops. The Oldman River Dam in Southern Alberta was built for agricultural use.
Most dams generate electricity, which is called hydropower. Two-thirds of Canada’s electricity comes from hydropower. When river water falls through a dam, it spins a machine called a turbine. A spinning turbine generates electricity. Hydropower is a renewable source of energy, because it can be used over and over again. Electricity is continually generated by dams, because water continually flows down rivers.
Building dams is sometimes controversial. Dams benefit people by storing water and generating electricity. However, dams flood land to create lakes. This can displace people from their homes and disrupt ecosystems.
Large concrete dams are built on rivers. Some dams control river flow to prevent flooding. For example, Calgary’s Glenmore Dam controls water flow in the Elbow River. This dam was built to prevent flooding of homes and businesses located close to the river. The Glenmore Dam also created a lake that stores drinking water for Calgarians.
Dams can also store agricultural water during dry seasons. Water in a dam-created lake can be sent down irrigation canals to provide water for crops. The Oldman River Dam in Southern Alberta was built for agricultural use.
Most dams generate electricity, which is called hydropower. Two-thirds of Canada’s electricity comes from hydropower. When river water falls through a dam, it spins a machine called a turbine. A spinning turbine generates electricity. Hydropower is a renewable source of energy, because it can be used over and over again. Electricity is continually generated by dams, because water continually flows down rivers.
Building dams is sometimes controversial. Dams benefit people by storing water and generating electricity. However, dams flood land to create lakes. This can displace people from their homes and disrupt ecosystems.
Figure E.4.12.8 – People use water directly for drinking, bathing, and cooking.
Figure E.4.12.9 – People use water indirectly through agriculture.
Figure E.4.12.10 – Raising beef cattle requires large volumes of water.
How Much Water Do You Use?
All people use water everyday to meet their needs. People use water directly for tasks like drinking, showering, and flushing toilets. However, humans consume far more water from indirect sources.
For example, agriculture consumes a lot of water. The plants we eat as food and weave into clothing require water to grow. The animals we eat as food consume water directly, as well as indirectly from plants. We obtain construction wood and paper pulp from trees, which need water to grow. Mining consumes water to extract metals for electronics and vehicles.
The term “water footprint” describes a person’s daily water use from both direct and indirect sources. People living in developed countries tend to have much larger water footprints than people in developing countries.
All people use water everyday to meet their needs. People use water directly for tasks like drinking, showering, and flushing toilets. However, humans consume far more water from indirect sources.
For example, agriculture consumes a lot of water. The plants we eat as food and weave into clothing require water to grow. The animals we eat as food consume water directly, as well as indirectly from plants. We obtain construction wood and paper pulp from trees, which need water to grow. Mining consumes water to extract metals for electronics and vehicles.
The term “water footprint” describes a person’s daily water use from both direct and indirect sources. People living in developed countries tend to have much larger water footprints than people in developing countries.
Watch More
Water Footprint
Watch this video to learn more about water footprints.
Watch this video to learn more about water footprints.
This video explains how much water is consumed in producing different types of food.
Lesson Activity
Problem:
In this lesson activity, you will calculate your personal water footprint and compare it to the average water footprint of Canadians and people from other nationalities.
Instructions:
- Go to this website: Water Footprint Calculator
- Work through the questions on the water footprint calculator, clicking on the answers that best apply to you. This website is from the United States, so here are some helpful hints as you work through the calculator:
- When the answer says “number” per “day”, you can change “day” to “week”, “month”, or “year”, by clicking the plus and minus buttons
- 1 mile is approximately 1.6 kilometers
- At the question that says “Choose your state”, choose Montana, which is just south of Alberta.
- When you receive your final calculated water footprint in gallons, multiply it by 3.78 to obtain your water footprint in litres.
Analysis Questions:
Think about the following questions very carefully. Then, type or write your answers. When you have your answers, click the questions for feedback. Use the National Water Footprint Explorer website to help you answer the questions.
Think about the following questions very carefully. Then, type or write your answers. When you have your answers, click the questions for feedback. Use the National Water Footprint Explorer website to help you answer the questions.
The average Canadian water footprint is 6400 L per day. Your personal water footprint might be higher or lower than this amount, depending on your lifestyle.
Two examples of countries with water footprints of 3000 L per day or less are Kenya in Africa, and India in Asia. These countries are developing countries. Many people in developing countries live in poverty, without indoor water, or the ability
to buy consumer products. As a result, their water footprint is much smaller.
If everyone had the same water footprint as Canadians, humans would use a lot more fresh water, which could lead to water shortages.
Try It!
Daily Water Use
Try this simple activity to track how you and your family directly use water during an ordinary day.
Materials:
DOWNLOAD this document. It provides a water tracking chart for you record your water use – it would be a good idea for you to print the document so you can carry it around with you during the day. It also has a place for you to answer questions at the end of the activity.
Instructions:
Carry the water tracking chart with you for one entire day. Under the column “Water Use”, write down each purpose for which your family directly uses water. Under the column “Number of Times”, make a checkmark for each time you use water in that particular way.
Try this simple activity to track how you and your family directly use water during an ordinary day.
Materials:
- Water tracking chart
- Pen or pencil
DOWNLOAD this document. It provides a water tracking chart for you record your water use – it would be a good idea for you to print the document so you can carry it around with you during the day. It also has a place for you to answer questions at the end of the activity.
Instructions:
Carry the water tracking chart with you for one entire day. Under the column “Water Use”, write down each purpose for which your family directly uses water. Under the column “Number of Times”, make a checkmark for each time you use water in that particular way.
Questions:
Think about the following questions very carefully. Then, type or write your answers. After you have your answers, click the questions for feedback.
Think about the following questions very carefully. Then, type or write your answers. After you have your answers, click the questions for feedback.
Your water use probably included drinking water, flushing toilets, and cooking.
There are many ways to save water. For example, when you brush your teeth, you can turn off taps instead of letting them run. If your clothes are not dirty or smelly, you can wear them several times before washing them.
Sharing:
Congratulations on completing this activity! When you use less water, everyone wins! Your water bill is less, there is less burden on your local water treatment facility, and it’s better for the environment. Do you have any great ideas for conserving water? Consider sharing your ideas in the course Sharing Forum.
Congratulations on completing this activity! When you use less water, everyone wins! Your water bill is less, there is less burden on your local water treatment facility, and it’s better for the environment. Do you have any great ideas for conserving water? Consider sharing your ideas in the course Sharing Forum.
Figure E.4.12.11 – Plants cannot grow without access to fresh water.
Figure E.4.12.12 – People in developing countries often struggle to get access to clean freshwater.
Figure E.4.12.13 – Many of the world’s rivers are polluted.
Water Is Always In Short Supply
Access to safe fresh water is difficult for nearly 1 billion people on Earth. We use a lot of fresh water for human activities, but leave it contaminated for direct human use. This leads to water scarcity, which is a lack of fresh water to meet basic human needs.
World population growth increases the problem of water scarcity. In 1975, 4 billion people lived on Earth. In 2015, the Earth’s human population was almost 7.5 billion people. The human population on Earth almost doubled in just 40 years, and it continues to grow. Earth’s rising population results in more demand for water resources. Urban areas with millions of people are using up ground and surface water resources for drinking, agriculture, and industry.
The issue of water scarcity is also increased by climate change. Drier climates in some areas mean that ground and surface water stores are not replenished as quickly as in the past. Climate change is melting glaciers around the world that supply water to rivers.
Although most Canadians currently have easy access to fresh water, we may be affected by water scarcity in the future.
Access to safe fresh water is difficult for nearly 1 billion people on Earth. We use a lot of fresh water for human activities, but leave it contaminated for direct human use. This leads to water scarcity, which is a lack of fresh water to meet basic human needs.
World population growth increases the problem of water scarcity. In 1975, 4 billion people lived on Earth. In 2015, the Earth’s human population was almost 7.5 billion people. The human population on Earth almost doubled in just 40 years, and it continues to grow. Earth’s rising population results in more demand for water resources. Urban areas with millions of people are using up ground and surface water resources for drinking, agriculture, and industry.
The issue of water scarcity is also increased by climate change. Drier climates in some areas mean that ground and surface water stores are not replenished as quickly as in the past. Climate change is melting glaciers around the world that supply water to rivers.
Although most Canadians currently have easy access to fresh water, we may be affected by water scarcity in the future.
Watch More
Water Scarcity
Watch this video to learn more about why global water shortages can’t be solved by individual people using less water.
Watch this video to learn more about why global water shortages can’t be solved by individual people using less water.
Many of the products we consume require a lot of fresh water to make them. Watch this video to learn more.
While individually using less water may not make the biggest difference to global water scarcity, it is still important and helpful. Watch this video for some ideas on how to conserve water around your house.
Make sure you have understood everything in this lesson. Use the Self-Check below, and the Self-Check & Lesson Review Tips to guide your learning.
Unit E Lesson 12 Self-Check
Instructions
Complete the following 6 steps.
Don't skip steps – if you do them in order, you will confirm your
understanding of this lesson and create a study bank for the future.
- DOWNLOAD the self-check quiz by clicking here.
- ANSWER all the questions on the downloaded quiz in the spaces provided. Think carefully before typing your answers. Review this lesson if you need to. Save your quiz when you are done.
- COMPARE your answers with the suggested "Self-Check Quiz Answers" below. WAIT! You didn't skip step 2, did you? It's very important to carefully write out your own answers before checking the suggested answers.
-
REVISE your quiz answers if you need to. If you answered all the questions correctly, you can skip this step. Revise means to change, fix, and add extra notes if you need to. This quiz is NOT FOR MARKS, so it is perfectly OK to correct
any mistakes you made. This will make your self-check quiz an excellent study tool you can use later.
- SAVE your quiz to a folder on your computer, or to your Private Files. That way you will know where it is for later studying.
- CHECK with your teacher if you need to. If after completing all these steps you are still not sure about the questions or your answers, you should ask for more feedback from your teacher. To do this, post in the Course Questions Forum, or send your teacher an email. In either case, attach your completed quiz and ask; "Can you look at this quiz and give me some feedback please?" They will be happy to help you!
Be a Self-Check
Superhero!
Self-Check Quiz Answers
Click each of the suggested answers below, and carefully compare your answers to the suggested answers.
If you have not done the quiz yet – STOP – and go back to step 1 above. Do not look at the answers without first trying the questions.
Soap and water from washing a car at home will flow down the street into storm sewer drains, which lead directly to rivers and lakes. Soap is a pollutant because it creates excess algae growth. The water in car washes travels through pipes to
wastewater treatment plants, where it is cleaned before being put back into the river or lake.
A diet lower in meat consumption and higher in vegetable consumption would reduce a person’s water footprint.
More humans on Earth need greater amounts of water both directly and indirectly, to support their needs. This reduces the fresh water supply on Earth.
If the heated water used to generate steam does not cool down before it is discharged, it can cause thermal pollution. Thermal pollution causes changes to aquatic ecosystems.
Bringing hazardous household chemicals to a waste disposal station allows them to be disposed of safely, without contaminating water and making extra work for water treatment plants.