effect of water pollution

Severe is that it is not actually illegal to dump pollutants into water bodies.
Sewage, sludge, garbage, and even toxic pollutants are all dumped into the water. Often, governments either do not care or simply look the other way.
Across the world, about half of all sewage is dumped into water bodies in its original form. No efforts are made to disinfect the sewage or to remove especially harmful pollutants.
Even if sewage is treated, problems still arise. Treated sewage forms sludge, which is sent out into the sea and dumped.
Many cities and countries dump sewage out at sea. Often, they place it not far from their own coastline, often killing all the sea wildlife in the dumping area.
In addition to sewage, chemicals dumped by industries and governments are another major source of water pollution.
Oil, such as that spilled by transport ships, has been dumped into the water. Every year, between 1 and 10 billion tons of oil are spilt, killing many species and destroying the ecosystem in the area. Cleanup efforts have been weak, as only about 10% of the oil is removed by the most successful efforts.