Water covers around 70% of planet Earth; it is found in the oceans, in rivers, lakes, ice-caps, glaciers, under us in aquifers, and in the atmosphere all around us. Humans too are around 70% water, and this means that we cannot survive without it so we had better look after our water sources.
Unfortunately, water pollution is a major problem across the globe; virtually any human activity can have a negative effect on the quality of our water environment. This is not good at all because if our water sources are polluted it affects the water that we use to grow our food, manufacture goods, feed our animals and plants, play in, bathe in and drink.
There are so many different causes of water pollution that it is impossible to guard against all of them:
- Sewage: With several billion people on the planet, sewage disposal is a major threat. There are millions of individuals in developing countries that do not have access to proper sanitation and defecate in the open causing faeces to end up in rivers. Even in developed countries, the disposal of sewage can be problematic and sewage waste often ends up pumped untreated into the sea, and this water ends up in rivers, causing various water-related illnesses.
- Waste Water is basically chemicals that are washed down drains and discharged from factories, and a lot of the approximate 5–10 billion tons of industrial waste generated globally every year ends up being pumped untreated into rivers, oceans, and other waterways.
- Chemical Waste includes detergents and highly toxic chemicals such as PCBs, which are now widely banned but whose effects on the environment will still be felt for many decades to come.
- Radioactive Waste from sources such as nuclear power plants and factories that reprocess waste fuel from nuclear power plants, which discharge radioactive waste water into the sea. This waste is then carried around the world on ocean currents.
- Oil Pollution from oil spills, routine shipping, and oil from motor vehicles and other sources that is poured down drains and ends up in oceans, rivers and other water sources.
Other forms of water pollution include plastics, invasive species of animals or plants, heat or thermal pollution from factories and power plants, and the disruption of sediment by hydroelectric power or water reservoirs.