 Current approaches to sewage management may include handling surface runoff separately from sewage, handling greywater separately from blackwater (flush toilets), and coping better with abnormal events (such as peaks stormwater volumes from extreme weather).Proper collection and safe, nuisance-free disposal of the liquid wastes of a community are legally recognized as a necessity in an urbanized, industrialized society.Sewage is a complex mixture of chemicals, with many distinctive chemical characteristics.