What are the reasons for impurity in water?
Untreated sewage directly into rivers and streams, which are used for drinking, bathing and washing. Sources of water pollutants – Direct additions. – Discharge of domestic, industrial, or agricultural effluents. – Direct application of herbicides to control water plants that interfere with man’s use of freshwaters. – Direct application of insecticides to fresh waters to destroy larvae of mosquitoes, the vector of malaria. – Molluscicides widely used in the tropics to control the snail vectors of schistosomiasis. – Indirect additions. – Run-off of insecticides and herbicides applied to the land. – Carelessly dumped waste pesticides and their empty containers in pools or streams. – Land fill sites and toxic waste dumps contaminate ground water.
