For a growing nation of more than a billion people and rapidly expanding urban areas, solid waste management is an issue that demands a rapid, scientific and sustainable solution, says Rishabh Sethi.Municipal Solid Waste (MSW) management is one of the major environmental issues plaguing Indian cities because improper management of MSW is extremely hazardous for their inhabitants. Studies have revealed that almost 90 per cent of MSW is unscientifically disposed off in open dumps and landfills without proper segregation, thus creating problems to public health and the environment. The quantity of waste generated is expected to increase significantly in the near future as the country strives to attain an industrialised nation's status by the year 2020. This will create a massive waste disposal problem in the coming years. Till now, the problem of waste was as one of cleaning and disposing. But a closer look at the current and future scenario reveals that waste needs to be treated holistically, recognising its natural resource roots as well as health impacts. Waste can be wealth; it has tremendous potential not only for generating livelihoods for the urban poor but can also enrich the earth through composting and recycling rather than spreading pollution as has been the case. Increasing urban migration and a high population density will make waste management a critical issue in the near future, if a radical new approach is not created.Our wasteConsumption linked to per capita income has a strong relationship with waste generation. As per capita income rises, more resources are spent on goods and services, especially when the transition is from low income to a middle-income level. Urbanisation not only concentrates waste, but also raises generation rates since rural consumers consume less than urban residents. India will probably see a rise in waste generation from less than 125,000 mt per year now to over 300,000 mt by the year 2030. Delhi alone is generating over 8,500 tonne MSW every day.Characteristics and composition The composition and the quantity of MSW generated form the basis on which a management system needs to be planned, designed and operated. In India, MSW differs greatly with regard to composition and hazardous nature, compared to MSW in the western countries. The composition of MSW at source and collection points was determined on a wet weight basis and it consists mainly of a large organic portion (40-60 per cent), ash and earth (30-40 per cent), paper (3-6 per cent) and plastic, glass and metals (each less than one per cent). It has been noticed that the physical and chemical characteristics of MSW change with population density, and it is observed that the differences in the characteristics of MSW indicate the effect of urbanisation and development. Storage and collection Storage for MSW at source is substantially lacking in most urban areas. The bins are common for both decomposable and non-decomposable waste (no segregation of waste is performed), and the waste is disposed off at a landfill. SPML is providing services for the storage and disposal of waste in three important zones in Delhi and has placed separate bins for the collection and storage of bio-degradable and non bio-degradable waste. The small tipper vehicles also have segregated compartments to collect the two type of waste separately, making it easier to segregate and dispose. Collecting MSW is the responsibility of corporations and municipalities. The predominant system of collection in most cities is through common bins placed at various points along the roads, and this sometimes leads to the creation of unauthorised open collection points. In most cities, a fraction of MSW generated remains uncollected on the streets, and what is collected is transported to processing or disposal sites. The collection efficiency is the quantity of MSW collected and transported from the streets to disposal sites divided by the total quantity of MSW generated during the same period. Many studies on urban environment have revealed that MSW collection efficiency is a function of two major factors: manpower availability and transport capacity. The average collection efficiency for MSW in Indian cities and states is about 70 per cent; studies show that the collection efficiency is high in the cities and states where private companies are employed for collection and transportation. Treatment and disposalThe two leading method of waste disposal being adopted in India include composting (aerobic composting and vermin-composting) and waste-to-energy (WTE) (incineration, pelletisation, bio-methanation). WTE projects for MSW disposal are a relatively new concept in India. Although these have been tried and tested in developed countries with positive results, they are yet to get off the ground in India largely because of the fact that their financial viability and sustainability are still being tested. The unscientific way of waste collection and disposal to landfill sites is damaging the environment in a major way and calls for immediate attention. What are the alternatives? Increasingly, the government is encouraging people to reduce the amount of solid waste they produce in the first place.In an effort to create sustainable waste management models based on community participation, and in partnership with other concerned agencies, SPML has developed effective waste management systems focussing on the simple principles of segregation, composting and recycling recovery. Such systems have been able to reduce waste going to landfill sites, thus saving land and reducing pollution. This, in turn, also saves the natural resources. As part of public awareness, SPML is holding workshops in schools and among the masses to inculcate the habit of segregation at source as per the MSW Rule 2000 in all the cities where it is providing the services of integrated solid waste management. The author is Executive Director, SPML Infra.