Grade by Grade
E. Earth and Space Systems · Air and Water in the Environment

Clean Drinking Water for Everyone

E1.3 E2.2 A1.3 A1.4 A3.1About 45 minutes
Learning goals
  • I can explain why safe drinking water is important for people and communities.
  • I can describe how fresh, clean drinking water is not available to everyone around the world, or everywhere in Canada.
  • I can describe some ways people get and clean drinking water.
  • I can design, build and test a simple water filter, and explain why it does not make water safe to drink.

Words to know

drinking water
Water that is clean and safe enough to drink.
germs
Tiny living things, too small to see, that can make people sick.
filter
Something that lets water pass through but catches dirt and bits.
drought
A long time with little or no rain.
boil water advisory
A message telling people to boil their tap water before drinking it, because it might not be safe.
community
A group of people who live in the same place.

Turn on the tap

When you are thirsty, you probably walk to the kitchen, turn on the tap and fill a glass. Easy!

But for many children around the world, getting water is not that easy. Some walk a long way every day to carry water home. Some families have water, but it is not safe to drink.

Today you will learn about drinking water around the world, and how people work to make sure everyone has it.

Fresh, clean and safe

To be good for drinking, water has to be:

  1. Fresh, not salty. (Remember: most of Earth's water is salty ocean water.)
  2. Clean, with no dirt, garbage or harmful chemicals.
  3. Safe, with no harmful germs. Germs are too small to see, so even water that looks clear can make people sick!

In many Canadian towns and cities, a water treatment plant filters the water and uses special treatments to kill germs. Then the water is tested to make sure it is safe.

Large open tanks of clear water with metal railings at a water treatment plant.
At a water treatment plant, water is cleaned in big tanks like these before it travels through pipes to people's taps. AI-generated image
1. Freshnot salty2. Cleanno dirt or garbage3. Safeno harmful germssaltdirtgerms
Drinking water must be fresh, clean and safe. Germs are too small to see, so water that looks clear can still be unsafe.

Water around the world

People everywhere need clean water, but not everyone has it close to home.

  • In some dry places, there is very little fresh water, especially during a drought.
  • In some places, there are no pipes to bring water to homes. People, often women and children, carry water from a well, river or tap that is far away. That can take hours every day, which means less time for school and play.
  • In some places, the water nearby is not clean, and people can get sick from drinking it.

Around the world, many millions of people do not have safe drinking water at home.

Drinking water in Canada

Canada has lots of fresh water. Still, not every community has safe tap water.

Sometimes a community gets a boil water advisory. This means people must boil their tap water before drinking it or cooking with it, to kill any germs. Usually this lasts a few days, after a pipe breaks or a storm.

But some First Nations communities, including some in Ontario, have had to boil their water, or bring in bottled water, for many years. This makes everyday life much harder. First Nations leaders and governments are working to fix the water systems, and many have been fixed, but there is still work to do. Everyone in Canada should have safe drinking water.

How do people get safe water?

  • Wells that reach clean groundwater.
  • Water treatment plants that filter water and kill germs.
  • Boiling water to kill germs.
  • Collecting rainwater in clean containers.
  • Water filters for homes and villages.
  • Taking care not to pollute lakes, rivers and groundwater in the first place!
Worked example

Let's design a water filter

Problem: We have a jar of muddy water. Can we design a filter to make it look clearer?

  1. Ask: We need something that lets water through but catches the mud and bits.
  2. Imagine and plan: A grown-up cuts a plastic bottle in half. Turn the top half upside down so it's like a funnel, with the cap off, sitting in the bottom half. Layers from bottom to top: cotton balls or a piece of cloth, then sand, then small pebbles.
  3. Create: Build the layers. Pour the muddy water in slowly.
  4. Test: Compare the water before and after. It drips out clearer!
  5. Improve: Try a thicker layer of sand, or pour the water through a second time. Does it get clearer?

The filter catches mud and bits, so the water looks clearer. But it can't catch germs or remove harmful chemicals, so the water is still not safe to drink.

muddy water insmall pebblessandcotton balls or clothclearer water drips out(still NOT safe to drink)upside-downbottle top
A homemade filter: pebbles, sand and cotton in an upside-down bottle top. The water comes out clearer, but it is NOT safe to drink.
TestHow the water looked
before filteringbrown and cloudy, with bits floating
filter 1: pebbles onlystill brown, a few bits caught
filter 2: pebbles + sand + cottonlight brown, no bits
filter 2, poured through twicealmost clear
Example test results: more layers, and filtering twice, made the water look clearer.

Safety: never drink it!

Your homemade filter water must not be tasted or drunk, even if it looks clear. It can still have germs. Pour it on outdoor plants or down the sink when you are done, and wash your hands.

Hands-on activity

Build and test a water filter

You need: a clear plastic bottle (a grown-up cuts it in half), cotton balls or a clean cloth, clean sand, small pebbles or gravel, a cup of muddy water (stir a spoonful of dirt into water) and a clear cup.

  1. Plan: Draw your filter. Which layers will you use? In which order?
  2. Create: Put the top half of the bottle upside down in the bottom half. Add your layers.
  3. Test: Pour in the muddy water slowly. Catch what drips out. Compare it with some muddy water you saved in a clear cup.
  4. Improve: Change one thing (more sand, another layer, filter twice). Test again. Which design worked best?
  5. Share: Tell a grown-up what worked and why the water is still not safe to drink.

Safety: A grown-up does the cutting. Never drink the filtered water. Wash your hands after.

Your turn

1

What three things must drinking water be?

2

Can water that looks clear still make you sick? Why?

3

What does a water treatment plant do?

4

What is a boil water advisory?

5

Name one way people in some places get water if there are no pipes to their homes.

6

Is the water from your homemade filter safe to drink?

7

What is a drought?

More practice: warm-up

1

Can people drink salty ocean water?

2

What are germs?

3

What kills germs in water at home if there is an advisory?

4

Name one layer you could put in a water filter.

5

Who does the cutting when you build a filter?

More practice: on your own

1

How can carrying water from far away affect a child's day?

2

Why does a filter with sand catch more mud than a filter with only pebbles?

3

Some First Nations communities in Canada have had to boil their water for many years. How might that make life harder?

4

Name two ways people can get safe drinking water.

5

Why is keeping lakes and rivers clean part of having safe drinking water?

Challenge

1

Your filter made the water look almost clear. Your friend wants to drink it. What do you tell them, and why?

2

A child walks 30 minutes to get water and 30 minutes back, two times a day. How much time is that each day?

3

Canada has a lot of fresh water. Why do some communities still not have safe tap water?

Check your understanding

Quiz

1.

Clear-looking water can still be unsafe because...

2.

A boil water advisory tells people to...

3.

Your homemade filter water looks clear. You should...

4.

Which is a way people get safe drinking water?

5.

What is a drought?

6.

Which is true about drinking water in Canada?

For parents and teachers

Big idea (E1.3): Fresh, safe drinking water is not equally available around the world or within Canada, and this affects health, time and daily life. Students also connect to sources of water (E2.2) and the technologies that make water safe (A3.1).

About long-term advisories: Some First Nations communities, including some in Ontario, have lived under long-term drinking water advisories. Many have been lifted in recent years, but some remain. Present this factually and without blame toward communities: the issue is about infrastructure and responsibility for funding it. If your child asks for more, Indigenous Services Canada publishes up-to-date information.

Engineering (A1.3) and safety (A1.4): The filter shows how layers remove particles. Stress firmly that it does not make water safe to drink. Adults should do all cutting.

How to help: Talk about how lucky (or not) your own water situation is, without frightening your child. Ask: "How would our day change if we had to carry all our water?"

Common difficulties: "Clear means clean." Repeat that germs are invisible.