Water is essential to life. It need not be spelt out exactly how important it is. Yet water pollution is one of the most serious ecological threats we face today.

Oil spill from the sunken tanker Prestige on the Galician Costa de la Muerte near Camelle, Spain. rel= © WWF / Raúl GARCÍA

What is water pollution?

Water pollution happens when toxic substances enter water bodies such as lakes, rivers, oceans and so on, getting dissolved in them, lying suspended in the water or depositing on the bed. This degrades the quality of water.

Not only does this spell disaster for aquatic ecosystems, the pollutants also seep through and reach the groundwater, which might end up in our households as contaminated water we use in our daily activities, including drinking.

Sources and effects of water pollution

Water pollution can be caused in a number of ways, one of the most polluting being city sewage and industrial waste discharge. Indirect sources of water pollution include contaminants that enter the water supply from soils or groundwater systems and from the atmosphere via rain.

Soils and groundwaters contain the residue of human agricultural practices and also improperly disposed of industrial wastes.

Types of water pollutants

Pollutants can be of varying kinds: organic, inorganic, radioactive and so on. In fact, the list of possible water contaminants is just too vast to be listed here.
Polluted waterway. Hudson Park, New York City, USA. 
© Vineus / Flickr.com
Polluted waterway. Hudson Park, New York City, USA.
© Vineus / Flickr.com