Types of water pollution
Water pollution is a serious threat to the every living organisms on this planet. The main source of this pollution is human activities and few may be natural like emission of natural gases and chemicals.
There are several sources of water. Hence the types of water pollution are also many in number, major of which are mentioned below.
1. Surface Water Pollution
It refers to the pollution of water resources found above the ground like rivers, lakes and streams. These sources are polluted by the rainwater runoff that transports pollutants to the water.
Surface pollution is also caused because of mixing of sewage and toxic chemicals from pesticides, fertilizers and petroleum products.
2. Chemical Water Pollution
Chemical water pollution is caused because of the various chemicals that mix with water from different sources.
- Toxic chemicals from industries pollute nearby lakes and rivers and harm aquatic life.
- Pesticides used in agriculture activities mix with rainwater runoff and enter water sources.
- Oil spills also harm birds and fishes that come in contact with the contaminate water.
3. Groundwater Pollution
We obtain our drinking water from aquifers below the Earth’s surface. When this water is polluted, it is referred as groundwater pollution.
Groundwater pollution is harder to control and treat because it is the pollution of water below ground. Groundwater is polluted from different sources such as pesticides, chemicals, etc.
4. Microbial Pollution
This is caused by various microorganisms known as pathogens such as bacteria, protozoa and viruses. Coliform bacteria are used as an indicator of pollution levels in water resources.
Some examples of microorganisms found in water that cause diseases are Salmonella, Giardia lamlia, Norovirus and Cryptosporidium parvum.
5. Ocean Pollution
Various contaminants like plastic, oil, garbage, toxic chemicals etc. pollute marine water. More than 80% of ocean pollution is caused because of pollutants from land.
Oil spills from marine accidents, routine shipping and oil from drains pollute the ocean water. Runoff from irrigated land lead to increase in nutrients which cause Eutrophication. Dumping of chemicals in oceans is also one major source of ocean pollution.
6. Thermal Pollution
Thermal pollution is the fluctuation of temperature of water bodies because of human activities. It can cause change in the physical properties of water resources.
Power plants and manufacturing industries use water as coolant which causes thermal pollution. Increase in water temperature lead to drop in oxygen levels which is harmful to aquatic life. The mixing of cold water from reservoirs with warm water in rivers is also a kind of thermal pollution.
7. Nutrient Pollution
It is caused because of introduction of excessive nutrients into water resources. When the level of nutrients rise in water bodies, eutrophication occurs. It helps in algal blooms which has adverse effects on the organisms living in the water.
Nutrient pollution is cause because of surface runoff of chemical fertilizers and pesticides from farmlands, emissions from fuel combustion and leaks from septic tanks. It is also responsible for high concentration of nitrate in water which has adverse effects on our health.