A protected well. Image credit totallandcare.org
ZIMSEC O Level Combined Science Notes: Testing the purity of water
- Most rural areas do not have access to running tap water
- Their water comes from various sources including dams, wells, boreholes, springs
- Some of these sources are produce unsafe water
- Water from these sources has to be protected from contamination by diseases causing pathogens
- When water is obtained from dams/river there is risk of contamination as people dump rubbish, urine and faeces in it
- Latrines and toilets must be built downstream wherever possible
- Ultra Violet treatment of water makes it safer for drinking
- If water is exposed to the sun’s UV rays it becomes safer to drink as the number of microorganisms in it are reduced
- Wells should be away/uphill from households and latrines
- This prevents water from seeping from toilets into the well
- Use a bucket, rope and windlass to reduce contact with the surface around top of the well
- Build a brick/cement surround to carry water spills away from the well
- Lining the well with bricks or cement
- Covering the well to prevent rubbish, children and animals from falling into the water and decaying
- Using a blair pump to raise water from the well
To access more topics go to the Combined Science Notes page.
