Municipal solid wastes (MSW) refers to all wastes collected by the local authority and is the most diverse category of waste including solid, semisolid or wet wastes with insufficient moisture content. It comprises waste from several different sources like:
(i) Construction and demolition waste.
(ii) Treatment plant waste like solid from gut chambers, industrial and domestic waste water from treatment plants.
(iii) Household or residential waste.
(iv) Commercial wastes including hazardous, explosives, pathological wastes from industries and hospitals.
The total quantities of municipal solid wastes collected in some of the major urban cities in India e.g., Mumbai, Delhi, Kolkata and Chennai, are in the range of 3500 to 5000 tonnes per day. It has been estimated that municipal solid waste production will reach about 50 million tonnes per year by 2010. While presently it is about 40 million tonnes per year. Municipal solid waste consists about 40% of the waste compostable in nature, and about 40% is mist material while the rest consist of mist material.