Water is the most basic and important component of living organisms.About 71 percent of the earth's surface is covered with water.Water pollution is the contamination of water bodies such as lakes,rivers,oceans,etc.It occurs when harmful chemicals are released ino water bodies without proper treatment. Causes:
1-The most common cause of water pollution is the discharge of city sewage and industrial waste into water bodies without paper treatment ,which pollutes clean and pure water.
2-Leakages from sewage pipes also pollute undergroundbwater.
3-Pesticides and chemicals sprayed on crops are washed deep into the ground by rainwater.This contaminates underground water.
4-Oil spillage from oil tankers also pollutes seas and oceans