Water pollution comes from two sources, nature-made and man-made, while water pollutants can be classified as chemical, physical and biological pollution according to the different pollution impurities.

Generally speaking, water pollutants include pathogenic microorganism and plant nutrients such as nitrogen, phosphorus and kalium, which can cause water eutrophication and worsen water quality; various oily substances which can impede the re-oxygenation capacity and damage the self-purification capacity of the water body itself; inorganic compound and chemical toxic substances that enter the water body can severely affect the water quality in production, daily life and agriculture.

Strengthened cleaning process and physical, chemical and biological methods should be respectively applied in the treatment of water pollution based on the types of pollution sources. Water resource management system should be improved to strictly prohibit casual discharge of waste water and strengthen the waste water treatment until reaching the discharge standard.