Water and sanitation


Water is a colourless liquid substance made up of hydrogen and oxygen gases. These gases are in the ratio of 2:1 (H2O)

Sources of water

  • Rain water
  • Artesian wells
  • Hot springs
  • Streams, lakes, rivers, swamps, ponds, oceans, and seas.

Properties of pure water

  • It is colourless
  • It is without suspended matter like germs.
  • It has no smell
  • Pure water is tasteless
  • Pure water boils at 100oC (212oF) and freezes at 0oC (32oF) at sea level.
  • Pure water forms lather (foam) very easily) with soap.

Uses of water to the body

  • Water makes up part of blood as plasma
  • Helps to dissolve the digested food for easy absorption in the body.
  • Maintains the shape of body cells.
  • Cools the body in form of sweat when it evaporates.
  • Helps in formation of body fluids such as tears, saliva, urine, sweat etc.

Other uses of water

  • For domestic use e.g. cooking, washing etc
  • For drinking by man, mammals, and birds
  • For irrigation in agriculture
  • Used in industries for cooling, washing machines and raw materials.
  • Used to generate hydro-electricity
  • Used by plants for photosynthesis

Preparation of safe water for drinking

  1. Boiling

When water is heated, it boils, to a temperature of 100oC (212oF) this temperature kills germs.

  1. Filtering

This is the process by which a clean or sterilized piece of cloth or local water filter.

Examples of solid impurities filtered are dirt, soil, stones, leaves, animals wastes etc.

NB: Filtered water is not safe for drinking because it may be containing some germs.

  1. Treatment of water

Treatment of water is when chemicals are added to kill germs in it.

Examples of chemicals used to treat water are; chlorine, water guard and aquasafe.

Advantages of chemicals used in water treatment

The chemicals kill germs in water

Disadvantages of using chemicals

  • They are expensive
  • They do not make water clear
  • They add some smell and taste to water.


Decanting is a method of removing large particles of objects from water.

Decanting is done by pouring water slowly from one container to another so that heavily particles are left behind. In this method, the three pot system is used to purify the water.

Water Impurities

Impurities are contaminants or foreign objects in water. Water impurities make it unsafe for use. Impurities may be soluble or insoluble organic.

Inorganic impurities

It consists of dissolved mineral salts which make water unsafe to use.

Organic impurities

These include bacteria , fungi and protozoa others may be dead plant materials such as leaves and grass.

Examples of water impurities

  • Human wastes
  • Animal wastes like urine , dung
  • Herbicides
  • Insecticides
  • Silt from erosion

Cleaning Clothes At Home

One main use of water at home is to wash clothes. This also called laundry

Step used in cleaning clothes at home


  • It involves selecting and putting clothes together according to colour , intensity of dirt, nature of the fabric , use of clothes etc.


It is the putting clothes in soapy water for some time.

Importance of soaking clothes

  • It helps to loosen dirt and dissolve stains
  • It saves time during washing as it a little effort to remove it.
  • It saves against tear and wear due to constant rubbing while washings.


It is the removal of dirt using water and detergent


Clothes are put in clean water. It helps to remove all soapy water from the clothes.


It involves squeezing excess water out of the clothes

Note : Woolen clothes should be dried without wringing because it may loosen the fabric and makes them to lose their shape.


Some clothes can be dried out completely under the sun.


It helps to remove creases from the washed clothes and bring them to their original form