Zanzibar Education Panel

Water pollution, in simple terms, can be defined as the contamination of the water bodies when pollutants are released into the water without thorough treatment and removal of harmful components.

1.Pesticides:Pesticides that are applied to and certain animals may drip onto the soil are carried into local stream and rivers by surface runoff. They can also drain down into groundwater, this contaminates the water , affecting the living organisms in the water and making the water unsafe for drinking

 

2. Fertilizers (nutrients):Many courses of pollution such as sewage, manure and chemical fertilizer, contain nutrients such as nitrates and phosphates.In excess level, the nutrients cause excessive growth of aquatic plant and algae. This is known as eutrophication. 

 

Eutrophication clogs waterways and blocks light from penetrating into the deeper water. When the aquatic plants and the algae die, they use up dissolve oxygen as they decompose. This lower the amount of oxygen available in the water for aquatic organisms such areas are commonly called Dead zones

 

3. Sediments:When forests are cleared, the root system that previously held the soil in place die. This exposes the soil to erosion by running water, the eroded sediments is deposited in nearly stream, rivers, and lakes. The sediments effects fish and other aquatic life in the water bodies.

Poor farming practice also expose the soil to pollution, thereby contributing to sediments pollution in water.

 

4. Industrial process:Most of the water that are used in production process in industrial is thereafter discharged into water bodies. This waste water may contain acids, alkalis, salts, ionics, chemicals, oils and, in some cases harmful bacteria. These substances affect the quality of water and interfere with the lives of water organisms.

 

 5. Oil spills: Oil spills in oceans cause major water pollution and problem for local wildlife and fisherman. A spill forms a thin layer of oil on the surface of water affecting the exchange of gases between the water and the atmosphere.

 

Land based petroleum pollution is also carried into waterways by rainwater runoff. This includes drips of oil, fuel and fluid from vehicles, and drips from industrial machinery. Drilling and extraction operation from oil and gas can also contaminate coastal waters and groundwater.

 

6. Sewage: In developing countries, about 90% of waste water is discharged directly into rivers and streams without being treated. Untreated sewage wastes gives rise to disease causing organisms in water bodies. Leaking septic tanks and other sources of sewage can cause groundwater and stream water contamination.

 

7. Mining activities: Mining causes water pollution in a number of ways, the include the following;The mining process exposes heavy metals and sulphur compound that were previously buried in the earth. Rainwater leaches these compound out of the exposed earth, resulting in acid drainage and heavy metal pollution that cn continue long after the mining operations have ceased.