Summary

In this Study Session, you have learned that:

• Water pollution is any contamination of water with substances that are detrimental to human, plant or animal health.
• 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.
• Water pollutants include sediments and suspended solids, organic matter, biological pollutants, plant nutrients and chemical pollutants.
• 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.
• 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.
• 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.
• The appropriate use of fertilisers and pesticides will minimise water pollution caused by agriculture.
• Selective planting of trees and vegetation can help stabilise soil and prevent erosion.
• Pollution control should ideally take place at the point of origin.
• Regulations control the type and volume of treated effluent that may be discharged to the environment.