Water pollution is the contamination of water bodies, usually as a result of human activities, that has a negative impact on their uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants mix with these water bodies. Contaminants can come from one of four main sources: sewage discharges, industrial activities, agricultural activities, and urban runoff including stormwater. Water pollution is either surface water pollution or groundwater pollution. This form of pollution can lead to many problems, such as the degradation of aquatic ecosystems or spreading water-borne diseases when people use polluted water for drinking or irrigation. Another problem is that water pollution reduces the ecosystem services that the water resource would otherwise provide.
Poster to teach people in South Asia about human activities leading to the pollution of water sources
Bauxite residue is an industrial waste that is dangerously alkaline and can lead to water pollution if not managed appropriately (photo from Stade, Germany).
Muddy river polluted by sediment
Solid waste and plastics in the Lachine Canal, Canada
A body of water or waterbody is any significant accumulation of water on the surface of Earth or another planet. The term most often refers to oceans, seas, and lakes, but it includes smaller pools of water such as ponds, wetlands, or more rarely, puddles. A body of water does not have to be still or contained; rivers, streams, canals, and other geographical features where water moves from one place to another are also considered bodies of water.
The Aubach, a watercourse in Germany
A fjord (Lysefjord) in Norway.
Port Jackson, Sydney, New South Wales
The Canal Grande in Venice, one of the major water-traffic corridors in the city. View from the Accademia bridge.