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Sewage: Dirty waste water which carries waste as a form of suspension is called
               sewage or waste water.

               Contaminants: The impurities dissolved and suspended in sewage are calked
               contaminants.


               An effective and closed drainage system for sewage is essential for the following
               reasons.

                     Sewage that stagnates as a puddle or pool breeds vectors of diseases such
                       as mosquitoes and flies. They can spread jaundice, malaria, cholera etc.
                       Vectors are the organism, typically a biting insect that transmits a disease or
                       parasite from one animal to other.
                     Sewage let off might pollute fresh water sources and public water distribution
                       systems. It can spread water borne diseases like amoebiasis, cholera,
                       dysentery, typhoid and hepatitis.
                     Exposed draining of sewage especially from hospitals and industries can
                       cause communal health problems.





















































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