WHAT IS WATER POLLUTION?

• Any biological or chemical change in the quality of water due to the presence of contaminants in water is called water pollution. Water pollution has affected the lives of humans and animals in all aspects. Water pollution is very hazardous to the environment.

• Sources of water pollution

1.Point sources : It includes small area outlets.

• Factory outlets
• Power plant outlets
• Underground mines
• Oil wells
• Sewage treatment plants

2.Non-point sources : It includes large area outlets.

• Soil erosion
• Agriculture land
• Acid deposition from atmosphere

• Categories of water pollution 

1. Ground water : 

• Ground water is most important natural resource on earth. It will be polluted when contaminants mixed with water on land and seep deep into ground water. Groundwater gets polluted when contaminants from pesticides and fertilizers to waste leached from landfills and septic systems make their way into an aquifer. Groundwater can also spread contamination far from the original polluting source as it seeps into streams, lakes, and oceans.

2. Surface water : 

• Surface water includes oceans, rivers lakes, ponds etc. Surface water get deteriorate due to farm waste and fertilizer runoff into river, Municipal and industrial waste discharges, algae in lake and pond etc. Also It deteriorate by Contaminants such as chemicals, nutrients, and heavy metals are carried from farms, factories, and cities by streams and rivers into our ocean.

The Most Common Types of Water Contamination :

1. Oxygen demanding wastes

2. Pathogen

3. Volatile organic compounds

4. Agricultural 

5. Thermal pollution

6. Heavy metals

1. Oxygen demanding wastes :

• Oxygen demanding wastes are substance that oxidize in the receiving body of water. These wastes are decomposed by bacteria (If they are biodegradable). During the process of degradation, the dissolved oxygen is utilize by the bacteria. Thus, the bacteria reduces the level of dissolved oxygen in the water. The dissolved oxygen is most important parameter of water, as its level drops, the life of fish and other aquatic organisms are fall under threat and in extreme case they does not survive.
• Oxygen Demanding Wastes are Comes from sewage, animal tissues, dead plants, pulp mills, runoff from farmlands, and dumping of wastes into streams. As the oxygen is demanded for the degradation of these waste so they are known as oxygen demanding waste.
• Moreover, DO level drops it creates undesirable odours, tests and color of water. which is unacceptable for domestic use.

2. Pathogen :

• The disease causing organisms, usually micro-organism that grows and propagates within the host is called the pathogen.
• The contaminate water is responsible for the spread of many disease. The natural water contains various types of living organisms. Some organisms born in water and remain in it due to its tendency. Some organisms are introduce in water by man during disposal of sewage in water.
• Some of the living organisms such as bacterias, viruses and protozoa are infections to human and they are responsible for the serious health problems. So they are known as pathogen.
• Following are the different pathogens present in water            1. Bacteria : It causes for cholera and typhoid.                  2. Algae : It causes for different type of skin disease.        3. Protozoa : It causes for amebic infections.

3. Volatile organic compound :

• Volatile organic compounds are most commonly found pollutants in ground water. They are often used as solvent in industrial processes.
• The VOCs are especially toxic and the presence in drinking water can cause for special concern.

4. Agricultural :

• The most common use of chemical in agriculture to increase crop quantity and quality is pesticides. It is used to control unwanted species of plants and animals. To prevent fungal infection, fungicide are also used.
• These pesticides and fungicides are washed off due to rainfall and irrigation system and get mixed with surface water bodies and deteriorate them.

5. Thermal effluents :

• After the introduction of industrialization, water gets more deteriorate through them. An accumulation of such contaminants in water which are produced by power plants, factories and mills and mixed with river and coastline water bodies.
• These power plants escape or discharge a large amount of heated water in the water bodies causing harmful for aquatic and marine organisms.

6. Heavy metals :

• Metals are introduced into aquatic system because of the weathering or erosion  of soil and rocks from volcanic eruption and such human activities like mining, processing etc.
• The term heavy metals has been used for those metals which have relatively higher density greater then 5.
• However, toxic matters are replaced the term heavy metals. Copper, chromium, lead, mercury, cadmium are the examples of heavy metals.

Effects of Pollution of Water :

1. It can be spread diseases in humans when they consume polluted water. It causes typhoid, cholera, hepatitis and various other diseases.
2. It can destruct aquatic ecosystem. A small change can threat many lives of organisms in water and it will be cause for collapse of entire ecosystem.
3. Chemicals in a water body, encourage the growth of algae. These algae form a layer on top of the pond or lake. Bacteria feed on this algae and this decreases the amount of oxygen in the water body which severely affecting the aquatic life.
4. It can also lead to serious disruption in food chains when toxins and pollutants in the water are consumed by aquatic animals (fish, shellfish etc) which are then consumed by humans.
5. The untreated sewage contains harmful chemicals that cause death in aquatic animals.

Measures to prevent water pollution :

1. Abstain from flushing contaminated liquids, pills, drugs, or medications down the drain. These substances contain scores of toxic materials that destroy the quality of natural water systems. Instead, use the recommended disposal methods.
2.  Ensure minimal use of bleach or detergents. During cleaning of laundry, it is vital to minimize the use of bleach and detergents. Instead, you can persist on only using phosphate-free detergents and soaps.
3. Reduce the use of herbicides, pesticides, and fertilizers. Excessive use of herbicides, pesticides, and fertilizers leads to water pollution as the chemicals contained in the products often find way into the water systems through surface runoff or infiltration into the soil. Minimizing their usage or using organic methods for pest, weed, and disease control can appreciably reduce water pollution.
4. Proper sewage treatment and management. Proper sewage treatment is required to limit the amount of toxic substances that normally end up in water systems such as lakes, rivers, and oceans. Also, individual homes that use septic tanks or cellar drains need to ensure proper management of their home sewage to avoid pollution.
5. Always conserve water. Play an active role in reducing water pollution by conserving water at all time. You can achieve this by ensuring the taps are always turned off when they are not in use. Conserving water reduces the amount of contaminated water that needs to be treated.
6. Skip the use of plastics. Plastic leftovers such as used plastic water bottles, disposable plastic plates, and plastic bags frequently end up in the oceans, lakes, streams and rivers, contaminating natural habitats and destroying aquatic life.
7. Practice organic farming. Organically grown crops reduce the quantity of herbicides and pesticides used in farming. It also promotes the use of organic fertilizer which promotes natural growth and eliminates the use of toxic chemicals found in synthetic fertilizers, which can penetrate into the ground and pollute water supplies.