Water Pollution Learning Path

Definition and practical meaning of water pollution

Water pollution (or aquatic pollution) is the contamination of water bodies—such as lakes, rivers, oceans, and groundwater—that negatively affects how the water can be used. Practically, water is considered polluted when human-made substances or energy change its nature so that it can no longer be safely used (e.g., for drinking or irrigation) or when its ability to support living communities (like fish and other aquatic life) is significantly harmed. The practical meaning is therefore tied to both loss of safe use and ecological damage. It is usually caused by human activities and occurs when contaminants mix with surface water or groundwater. Major sources include sewage discharges, industrial activities, agricultural activities, and urban runoff (including stormwater). Pollution can come from identifiable point sources (such as wastewater outfalls, storm drains, or oil spills) or from diffuse non-point sources (such as agricultural runoff). Contaminants take many forms, including toxic chemicals (oil, metals, plastics, pesticides), nutrients, pathogens, and physical/chemical stressors like changes in pH, oxygen levels (hypoxia/anoxia), temperature, turbidity, and salinity. In practice, water pollution leads to degraded aquatic ecosystems and can spread waterborne diseases when contaminated water is used for drinking or irrigation. It also reduces ecosystem services such as providing clean drinking water. Control and reduction require infrastructure and management (e.g., sanitation and sewage treatment, industrial wastewater treatment, erosion and sediment control, and stormwater management), supported by legislation and ongoing policy evaluation.

0/2 modes complete

Water bodies affected: surface water and groundwater

0/2 modes complete