The last century has witnessed extraordinary scientific achievements, expansion and proliferation of industries and factories, improvement in hygiene and medicine, population growth accompanied with conspicuous consumption and concentrated human habitation in metropolis and mega cities. It is simply no longer possible to avoid solid, liquid or gaseous waste – disposing of which is increasingly burdensome. Government authorities have acknowledged the importance of management of municipal solid as well as domestic liquid waste such as sewage and sullage etc. The UN initiated Stockholm Human Environment Conference in 1972 saw the change in policies from environmental indifference to environmental concern and led into a comprehensive environmental legislation. Indian Government has also created several organisations to help abate and manage pollution and has enacted legislations including Environment (Protection) Act 1986 which includes Domestic Sewage Discharge Standards, Municipal Solid Waste Rules 2000, Biomedical Waste Rules 1998 and amendments, Hazardous Waste Rules 1989 and amendments, Plastic Waste Rules 2011, Electronic Waste Rules 2011 etc.
The problem of sanitation with the advent of non-biodegradable plastic containers and polythene wrappers has now turned even more serious. With a highly dense population coupled with a tropical climate – the problem of solid waste disposal is aggravated as the municipal waste disposal commonly practised in Asia is through open dumping. The level of leachability from the dumped waste increases with high precipitation. Municipal solid waste (MSW) management is an obligatory function of urban local bodies (ULBs) in India. However, lack of political will, inadequate financial resources, institutional weakness, improper choice of technology and public apathy towards solid and liquid domestic waste management have made this service far from satisfactory.
Per capita waste generation ranges between 0.2 kg and 0.6 kg per day (India Infrastructure Report 2006, CPCB) in Indian cities – with an annual increase of about 1.3 per cent, amounting to about 1.15 lakh MT of waste per day and 42 million MT annually (NEERI & Annepu, R. K. 2012). As per the CPCB 2007 data, 366 cities in India that generated 31.6 MT of waste are currently generating 47.3 MT – almost a 50 per cent increase in one decade. It is estimated that these cities will generate about 161 MT of MSW by 2041, a five-fold increase in four decades. At this rate the total urban MSW generated in 2041 would be 230 million TPY (630,000 TPD), (Table 1).
MSW Rules 2000 mandate landfills to be located away from habitation clusters and places of social, economic or environmental importance. The increase in MSW thus will have significant impacts in terms of land required for disposing the waste – farther the landfill gets from the point of waste generation, greater will be the transportation cost. It is estimated that the waste generated by 2001 would have occupied 240 sq km or an area – half the size of Mumbai; waste generated by 2011 would have occupied 380 sq km or about 220,000 football fields or 90 per cent of Chennai; waste generated by 2021 would need 590 sq km which is greater than Hyderabad (583 sq km) ( Annepu 2012, Columbia University, USA). The Position Paper on the solid waste management in India by the Ministry of Finance (2009) estimates a requirement of more than 1400 sq km of land for solid waste disposal by the end of 2047 – if MSW is not properly handled it would require an area equal to Hyderabad, Mumbai and Chennai together!
Under such circumstances, dumping of waste into rivers, lakes, canals and creeks cannot be avoided. The quality and the availability of the fresh water is one of the greatest environmental challenges. Most of our water sources are polluted with untreated/partially treated wastes from industry, domestic sewage and fertiliser/pesticide run off from agricultural fields. The point source pollution as per the 2001 Census from the sewage generation from Class I cities and Class II towns including metropolitan urban centres is 38,270 million litre/day (MLD) whereas the treatment capacity exists for only about 11787 MLD accounting for only 31 per cent. The municipalities and other civic authorities are unable to handle this massive task. There is thus a need for strategic comprehensive multi-pronged water quality management approach which includes strict implementation of pollution control laws, promotion of cleaner technologies, fiscal incentives and economic instruments of appropriate prices, taxes and property rights. Amongst the metropolitan cities, Delhi has the maximum treatment capacity followed by Mumbai, yet the capacity of both remains below the amount of waste water generated. (Table 2).
Discharge of untreated domestic waste is a predominant source of pollution of aquatic resources in India. There are 14 major river basins in the country which occupy 83 per cent of the total drainage basins and contribute to 85 per cent of the total surface flow. They house 80 per cent of the country’s population. To cope up with this problem, there are about 284 sewage treatment plants (STPs) in India out of which only 231 are operational utilising about 72 per cent of the capacity. Thus, there is a large gap between waste generation and its treatment (CPCB, 2004, 2005, 2009, Agrawal, Sanjeev 2010, Gautam et.al. 2011).
Worldwide, technological options available for processing of MSW include sanitary dumping, composting, anaerobic composting/biomethanation, vermi-composting, incineration, pyrolysis, gasification, plasma arc gasification and production of refuse derived fuel. The technologies that have been attempted in India during the last three decades are windrow composting; mass burn, combustion of refuse derived fuel, biomethanation, and at a small scales numerous vermi-composting initiatives. The technologies used for the liquid waste are mostly activated sludge process (ASP), up flow anaerobic sludge blanket (UASB), rotating biological contractor (RBC-disc reactor), trickling filter, high load ASP followed by biofiltration and chemical coagulation, high rate biofiltration, fluidised bed reactor, and the sequencing batch reactor. Technological solutions attempted in India have encountered initial failures. Major reasons for these failures are the plants that were designed to handle more waste than could be acquired; non-allocation of funds for plant maintenance and inappropriate technologies. Municipal Solid Wastes (Management and Handling) Rules (2000) lay emphasis on participatory model involving citizens. Improvement in landfill sites as well as identification of new sites, as per the rules, remain undone in most of the cities.
The government has taken several measures to protect the water resources from water quality degradation. The important ones are National River Action Plan, incentives for control of pollution to industries, establishment of common effluent treatment plants for small scale industries and adoption of ‘eco-mark’ for the eco-friendly products. Other efforts include restoration of water quality of the national aquatic resources through a series of legislations and a large number of institutions. There are number of supportive and allied regulations available for the protection and conservation of the environment. In sum, there are enough provisions available – the need of the hour is the implementation of such provisions and use of context-specific appropriate technologies seeking a proactive support from citizens.