Water Contaminants
Basic Science and Technology
Primary 3.
2nd Term
Second term
Scheme of work with lesson note
Week: Six
Class: Primary Three
Topic: Substances that contaminate water
Behavioural objectives: At the end of the lesson, pupils should be able to:
1. identify and name some substances that make water unfit for drinking.
2. explains how dead and decaying animals contaminate water
3. explains how contaminate water.
4. discuss how dumping of refuse in rivers contaminate water.
Instructional material/Reference material: Charts showing ways water can be contaminated, Water contaminated with dust, sand particles
Building Background /connection to prior knowledge: pupils are familiar with Danger of drinking bad water
Content:
How decay plant and animal contaminate water:
When plants and animals die, they settle to the bottom. Under normal conditions this causes the water body to gradually fill with sediment and organic material and it makes it smell and stink because germs and worms are sedimented and settled in it.
How leaking pipe and underground water contaminate water:
Leaky pipes can allow contaminants into our drinking water. … The pressure in mains water pipes usually forces water out through leaks, preventing anything else from getting in. But when there is a significant pressure drop in a damaged section of pipe, water surrounding the pipe can be sucked in through the hole. Underground water contamination occurs when man-made products such as gasoline, oil, road salts and chemicals get into the groundwater and cause it to become unsafe and unfit for human use. … For example, pesticides and fertilizers can find their way into groundwater supplies over time.
How human waste contaminate water:
Human excreta,urine and the lack of adequate personal and domestic hygiene have been implicated in the transmission of many infectious diseases including cholera, typhoid, polio. This really leads to contamination of water which called water disease/water borne disease.
How dumping of refuse in the river contaminate water:
Organic waste (e.g., wood wastes) can have chemical and biological impacts on rivers and streams. Among the many impacts are interfering with the establishment of aquatic plants, affecting the reproductive behavior of fish and other animals, and depleting the water of dissolved oxygen as the wastes decompose.
Presentation
Step 1 : The class revises the previous topic
Step 2 : Introduction Of the new lesson
Step 3 : Allow learners to give their own ideas and suggestions and corrects them when the needs arise
Evaluation: The teacher asked questions on what has been taught.
1. identify and name some substances that make water unfit for drinking.
2. explains how dead and decaying animals contaminate water
3. explains how contaminate water.
4. discuss how dumping of refuse in rivers contaminate water.