Urban areas have the potential to pollute water in many ways. Runoff from streets carries oil, rubber, heavy metals, and other contaminants from automobiles.
Petrochemicals residues and debris from tyres are washed down storm drains besides roads. The water coming off the surface of roads can contain a hazardous cocktail of chemicals.
Untreated or poorly treated sewage can be low in dissolved oxygen and high in pollutants such as fecal coliform bacteria, nitrates, phosphorus, chemicals, and other bacteria.
Agricultural run-off often causes algae in the water to "bloom" or reproduce at an artificially fast rate, until the water is choked with organisms, which then tend to suffocate and die as there is not enough oxygen in the water to support them.
Many animals are kept in intensive rearing sheds and are routinely fed drugs such as antibiotics. As around 75% of such drugs may be excreted, the resultant manure becomes a potential source of water pollution.
Many things can cause water pollution such as garbage dumps, toxic waste and chemical storage and use areas, leaking fuel storage tanks, and intentional dumping of hazardous substances
Rapid algae growth is caused by multiple things such as agricultural run-off. In The National Fish Hatchery in Neosho, they are actually having to move fish to another site because the fish were being suffocated by the algae.
Every third sample from sources of drinking water in Russia fails to meet acceptable standards due to chemical contamination, according to Russian consumer watchdog agency Rospotrebnadzor. Moreover, nearly half of Russia’s population lacks safe drinking water.Industrial and chemicals waste is often dumped into waterways, including hydrogen sulfide