Summary of Study Session 4

In Study Session 4, you have learned that:

1. Water pollution is any contamination of water with substances that are detrimental to human, plant or animal health.
2. Water pollutants can be of point or non-point source, depending on whether substances are discharged directly into a body of water or indirectly from diffuse sources.
3. Water pollutants include sediments and suspended solids, organic matter, biological pollutants, plant nutrients and chemical pollutants.
4. Biological pollutants include bacteria, viruses, protozoa and helminths. They mainly enter the water through faeces from infected people and animals, and are the cause of many water-related diseases.
5. Major sources of water pollution include human excreta; manufacturing and industrial plants; animal rearing and agricultural activities; landfill sites; and urban surface water run-off.
6. Measures to protect water sources from faecal pollution include ending open defecation, the proper siting of latrines and septic tanks, and careful operation of sewage treatment works.
7. The appropriate use of fertilisers and pesticides will minimise water pollution caused by agriculture.
8. Selective planting of trees and vegetation can help stabilise soil and prevent erosion.
9. Pollution control should ideally take place at the point of origin.
10. Regulations control the type and volume of treated effluent that may be discharged to the environment.