Water is a basic need of the life of man. It is used for bathing, cleaning, cooking, air conditioning etc.
After use in the above activities, waste water is flown as effluent in the surrounding areas.
Such waste contains detergent for washing clothes, decomposed vegetables and fruits, ash of hearth, domestic refuse, pieces of cloth etc. Such waste water causes pollution by mixing with nearby water sources after passing through open drains.
Man requires 130 litre water per day on an average 70 to 80 per cent part of such water is flown away after being used. This water, accompanied by pollutants, flows into the water sources. Due to fast increasing population, quantity of domestic effluents has also increased. With the increasing tendency of urbanization, problem of disposal of domestic effluents has increased.
River Ganges is fast converting into a dirty drain due to disposal of domestic effluents, disposed in it by cities located on its banks. At present, pollutants of 48 ‘A’ class cities and 66 ‘B’ class cities situated on the banks of this river are being disposed in large quantities every day.
In Delhi, 96 crore litre filthy water is poured in river Yamuna through 17 drains which results in a huge amount of pollution. Similarly, 87 per cent out of the total domestic waste in Mumbai and 89 per cent out of the total domestic waste in Kolkata is being disposed in rivers and lakes.
It has been presumed since ancient times that river water is pure but it is no longer so. In developed countries, suitable method of treating domestic waste is being adopted but in developing countries, there has been no progress in this direction. In all cities, domestic refuse is thrown here and there, which gives birth to different epidemics.
Domestic waste also includes plastic. At present, the use of plastic bags is increasing. After being used they are flown away in the water. Since they neither decay, nor dissolve, hence their disposal has become difficult. Harmful bacteria develop when they are immersed in water which pollutes the water.
There is no method for their disposal in India but developed countries have developed the technique for disposing them. Among all domestic wastes, the most harmful is water used for cleaning. This water is produced by cleaning of house, cleaning of utensils and washing of clothes. Ordinary soap does not fully clean the clothes hence detergent soap is used to clean clothes, which is very harmful.
Water is polluting fast because of the increasing use of detergent. It is difficult to refine detergent containing water, and the phosphorus produced by it develops algae which is harmful vegetation. Growth of algae in the water of rivers and lakes makes the water unfit for drinking. If these detergents mix in any water source, they do not go away easily. Neither water treatment methods nor the bacteria in the water can affect them, and its permanent effect proves very harmful.