The Water Treatment Process
Making Water Drinkable
Review Questions
 1. A rose bush was watered on Sunday.
After six days the soil was dry and the
leaves were wilting. Explain what happened
to the water.
 2. Why is the earth’s water never used up?
Water Treatment
 Water Treatment is the process of making
water suitable for desired end use (such as
drinking).
 Water Treatment occurs as a Systematic
Process through a Water Treatment Plant
A Water
Treatment
Plant
Water Treatment Process - Steps
 Remove large objects – a metal screen
blocks objects from entering the pipe
 Add alum (a chemical) – attracts waste
solids to form clumps – these are called floc
(sticky clumps formed from the reaction of
alum in water, combined with sand and
other waste solids)
Steps
 Water and Floc enter settling tank (water
moves slowly) where floc settles to the
bottom
 Partially cleaned water from top of tank
moves through a sand and charcoal filter to
remove remaining waste
 Chlorine added to kill organisms
 Water stored or delivered
Other Treatment Options
 1. Reverse Osmosis – mechanical pressure
forces water through a membrane that acts like
a fine filter
 2. UV radiation – destroys most viruses and
micro-organisms
 3. In nature, water absorbs minerals calcium and
magnesium from surronding rock – this makes
water “Hard”. This is safe to drink but when
heated leaves mineral deposits.
 4. Boiling – boil for 3 minutes to kill microorganisms and bacteria and drink within a few
hours
Stormwater Management
 During spring; too much water for plant to handle
so stormwater goes directly to lake
Using Water Sustainably
 Only a small amount of world’s water is
suitable for human use.
 A rising population, pollution and other
factors are limiting this resource.
 Sustainability means working and behaving
in a way that protects resources to ensure
that they are available to future generations.
Homework Questions
1. List and describe the six main steps that
water goes through in the water
treatment process
2. Is clear, colourless and odourless
drinking water always safe to drink?
Explain.
3. Why is it important to ensure that treated
water remains safe to drink when it is
stored after treatment? Describe one
way to make stored water safe.