ICOR – waste management study report

Climate change, energy and decentralized solid waste management in Mumbai

With increasing population and urbanization, municipal waste management in our cities is emerging as a major problem, which is going to get even worse in the future. Urban India now generates about 48 million tonnes of waste annually. With increasing population, urbanization, and rising incomes and consumption, this is expected to grow to 300 million tonnes, or over six fold, in about another four decades; the retail trade sector is growing at a fast pace of 20 per cent a year. This will lead to the generation of even more wastes with serious implications for urban sanitation and health, the environment and global warming and climate change. And where will this waste be disposed, considering that large cities in the country are already finding it difficult to locate the land needed to dispose their waste?

 

Of the green house gas (GHG) emissions (which include carbon dioxide, methane, nitrous oxide, etc) that cause global climate change, the bulk, about 40 per cent, comes from the energy and transport sectors. Other sources include chemical-intensive agriculture, particularly the heavy use of nitrogen fertilizer, which accounts for 15-25 per cent, and open and decaying urban waste dumps. Studies have shown that open waste dumps contribute about 2 per cent of the total global GHG emissions, mainly methane which traps much more heat than carbon dioxide (but is less abundant and short-lived in the atmosphere than carbon dioxide). Open waste dumps   account for about 12 per cent of the total global emissions of methane

A study1 by The Energy Research Institute (TERI), New Delhi, estimated that, in 1997, waste dumps in India released about 7 million tonnes of methane, and this is likely to rise to 39 million tonnes by the year 2047. The country’s net emissions (in terms of carbon-equivalence) from wastes grew at 7.3 per cent annually during the period 1994-2007, according to a recent report by the Union Ministry of Environment and Forests.

In this context, proper management of wastes, especially municipal wastes, in large and heavily populated cities acquires importance.

Following a public interest litigation, the Supreme Court in 2000 ruled that all Class 1 municipalities should initiate systematic collection, segregation and processing of municipal wastes by the year 2003. Despite this rule, only 22 per cent of the municipalities in 24 states now collect urban waste regularly, only 17 per cent have provided for the proper storage of wastes, and only 11 per cent   process wastes, according a recent report by the Comptroller and Auditor-General of India.

 

Most big municipalities continue to dump wastes in open grounds. Such central dump sites create serious health and environmental problems and release GHGs. Much of these wastes going to central waste dumps can be   reused and   recycled, and the rest converted   into compost/fertilizer and energy (methane and electricity) using low-cost technologies. Besides creating a cleaner environment, this will help conserve materials, offer a sustainable source of renewable energy and reduce GHG emissions -- goals that need to be strongly pursued in the face of an acute shortage of energy and climate change.

In this context, this study looks at the growing problems of waste management in Mumbai, how the Brihanmumbai Municipal Corporation (BMC) plans to tackle the problems and possible community-based alternative solutions.

 

WASTE MANAGEMENT IN MUMBAI -- A ‘MOUNTING’ PROBLEM

 

Mumbai generates about 6,500 tonnes of waste every day, including wastes from households, markets, hotels and restaurants and commercial establishments. Fifty per cent of this waste is biodegradable (mainly kitchen and market waste or ‘wet waste’), 20 per cent ‘ dry’ recyclable waste such as metal, glass, rubber, cloth and plastics, and the rest is construction and other wastes. On an average, a person generates about half a kilogram of waste a day, with the middle and the upper classes producing much more waste per person than the poor. About 1,110 heavy vehicles (including 850 private vehicles) carry these wastes to three dumping grounds at Deonar, Mulund and a new one at Kanjur Marg, making around 1,900 trips a day across the city. The older dumping grounds were on the outskirts of the city when they started but today, because of the rapid expansion of the city and population pressure, they are surrounded by residential colonies. The Deonar dump, especially, has now grown into a stinking waste ’mountain’, about 47 metres high and overflowing, creating several health and environmental problems for the residents as well as the BMC. Besides, there are about 182 illegal open waste dumps in the city. The waste generated in the city is estimated to grow by around 50 per cent to 9,000 tonnes a day in the next four decades, forcing the BMC to locate new dumping grounds which it is finding difficult to do.

 

Apparently, with the fast growth of population and the city, waste management is becoming increasingly intractable, right from waste collection to disposal.   Initially, the municipality collected garbage from community bins placed at various roadside locations where people would dump their wastes and municipal vehicles collected the wastes from the bins. However, soon these open bins were overflowing, and garbage was thrown all around the bins and in the neighbourhood, causing stench and problems of public sanitation and health, besides being eye-sores. To avoid these problems and to ensure garbage was not dumped on roads, the BMC, under the new municipal management bye-laws of 2006, introduced a system of point-to-point collection of wastes, under which housing societies and commercial establishments would collect their wastes and hand them over directly to BMC vehicles every day at various pre-designated points. However, the new system could not improve the situation much. For, it could not cover all parts of the city, particularly predominantly slum areas, and often housing societies could not collect all the waste before the vehicles arrived. 2

 

Waste collection is thus not efficient, particularly in crowded residential areas with narrow lanes which the trucks cannot enter. Often, wastes remain uncollected. Waste collection and sanitation services in the slums are even poorer and, in many areas such as in ‘non-recognised’ slums, totally lacking.   (Nearly 60 per cent of Mumbai’s population of 1.2 crore is in slums). People also continue to throw garbage on the streets. As a result, “half the garbage never reaches the bins and dumpsites”, says Ashish Kumar Singh, Additional Municipal Commissioner responsible for the city’s waste management.3 Garbage is found all over city, piled up at street corners, strewn along roadsides and dumped in open spaces and drains. Wastes, especially plastics, piled up in drains block drainage , often leading to flooding of the streets during the monsoon. In fact, clogged drains and rivulets running through the city caused heavy damage to life and property during the intense rains (said to be the result of the changing rainfall patterns because of the global warming) and the consequent flooding in Mumbai in July 2005.

 

Poor waste handling

 

Though the Municipal Solid Waste (Management and Handling) Rules 2000 require that the municipality provide infrastructure for the collection, storage, segregation, transport , processing and disposal of the wastes, this is hardly done. On a rough estimate, only about 5 per cent of the city’s waste is segregated into wet (biodegrable) and dry wastes. Much of the segregation is done by the city’s nearly 300,000 rag-pickers, mainly poor and homeless women and children; they sell the dry waste to recyclers. To some extent, sweepers in housing societies segregate and recycle dry wastes to earn some extra income. Advanced Local Managements or ALMs (groups of local citizens formed, with support from the BMC, to help management of wastes in local areas) also organize segregation and processing of wastes locally. The rest, about 95 per cent of the wastes, goes to the three dump yards where they are disposed of without any treatment or processing.

 

The waste dumps have therefore been causing serious health and environmental problems and ground water contamination from water leaching from the dump. For example, people living around the Deonar dumping ground, the oldest of the three, have been complaining of increasing allergies, cough, asthma and other respiratory ailments, foul smell, toxic fumes, smoke from fires in the dumps, etc. They have in fact formed the Smoke-affected Residents’ Forum (SARF) and have been fighting legal battles against the municipal corporation in the Bombay High Court for the closure of the dump. Health surveys conducted by the BMC and others have confirmed these problems, particularly air pollution.

According to SARF, air pollution from the Deonar dump has affected the health of about 2.5 million people.

 

The BMC has been scouting for new sites to dump the increasing wastes farther away from the city but has not been able to find any. An old dumping ground at Gorai, in the far-northern suburb, was closed recently as it outgrew its capacity, and another one, at Malad, close to residential areas, had to be shut down under court orders following complaints from residents about stench and respiratory problems.

 

The corporation now plans the “partial closure” of the Deonar and Mulund dumping grounds and develop “sanitary landfills” (sanitary dump sites) and waste processing plants at the sites. A sanitary landfill and waste processing plant will also be built at Kanjur Marg. At these sanitary landfills, wastes will be compacted and covered with different layers of linings -- construction debris, high-density polythene, etc -- to prevent water seeping into the waste dump. Deep foundation walls will be built to prevent water from the dumps from contaminating ground water and water leaching out will be treated and released into the drainage systems and into the creeks nearby.

 

At Deonar, which now receives 5,000 tonnes of waste every day, part of the dump yard will be closed and turned into a “green belt”. The methane released from this closed dump will be trapped and collected through gas wells and pipes, and used to produce 3-4 kW of electricity a day; a new sanitary landfill on another part of the dump will continue to receive 2,000 tonnes of waste a day. The whole project will cost about Rs. 5,500 crore over the next 25 years, and this high cost has come in for much criticism. The corporation was hoping to earn carbon credits (for the reduction of GHGs following the partial closure of the waste dump), as it did from the closure of the smaller Gorai dump two years ago, and sell each certified emission reduction unit at Euro 12 in the international market, “but the calculations have all gone bust now that there is a likelihood that Kyoto may not get extension”, said Bhaichandra Patil, the BMC’s chief engineer for solid waste management, recently.4 Meanwhile, SARF has been demanding the full closure of the Deonar dump instead of a partial closure. At the Mulund, part of the organic wastes which used to be dumped here will be processed into methane in a bio-methanation plant which in turn will be used to produce electricity. About 500 tonnes of waste a day when processed into methane will generate about 6 MW of electricity, according to BMC’s estimates

 

(The wastes discussed here are mainly kitchen and market wastes. The city also generates bio-medical wastes from hospitals and other healthcare units, electronic wastes from electronic products, and construction debris which are not discussed here. The bio-medical wastes and electronic wastes are handled under separate rules and guidelines.)

 

Problems of centralized waste management systems

 

A centralized waste management system , such as in Mumbai and also in many other big cities, involves collecting huge amounts of wastes from all corners of the city everyday and transporting these in heavy vehicles over long distances for disposal at a central dump site. This has several disadvantages as discussed earlier. These include:

 

  • The enormous and increasing cost of collecting and transporting wastes. The BMC, for instance, has an annual budget of   Rs. 10,000 million for solid waste management, and much of this, over 75 per cent, is spent on collecting and transporting wastes. Even so, given the extent of garbage generated, waste collection is not efficient, and the garbage is not sorted and recycled, which is a waste of resource.

 

  • Transport of wastes across the city adds to air pollution and increases fossil fuel use.

 

  • Open dumps cause a range of environmental and public health problems, and also emit GHGs   which contribute to global warming and climate change.

 

  • Driven mainly by technology, heavy equipment and national and international equipment vendors in a bureaucratic milieu, it does not involve local communities in planning and managing waste collection, segregation, recycling and processing locally.

 

  • Sustainability is not a concern in such centralized waste management systems.

 

Even when large dump yards are “scientifically closed”, they can still have significant environmental impacts, especially GHG emissions. Methane emission is “an issue which affects all landfill sites accepting municipal solid waste (MSW), and the contribution of methane emitted from landfills to global warming is significant”, noted an extensive review 5of the environmental and health effects   of landfills in the UK done for the Department for Environment, Food and Rural Affairs, UK. “A considerable benefit can be achieved by collection and combustion of landfill gas, but there is a practical limit to the proportion of gas generated which can be collected in this way. Because of the significance of methane emissions from landfills, alternatives to landfill for MSW are often viewed as having a positive benefit on global warming by reducing the need to landfill biodegradable waste” ( italics added). The study estimated that methane emissions from MSW in the UK accounted for nearly 30 per cent of the total methane emissions from all sources in the country.

 

A more recent review (2008) of sanitary landfills in and outside North America concluded that “the disposal of wastes in landfill sites has increasingly caused concern about possible adverse effects on populations living nearby, particularly in relation to those sites where hazardous waste is dumped…”6Most such landfills will still cause groundwater contamination and health problems for residents around. The study listed several possible failures of landfill systems. These include: eventual failure of the landfill cover to prevent rainfall from entering the dump; permeation through the liner;   development of cracks and leakage in the liner; inadequate buffer land around the dump; and insufficient funds for long-term maintenance. There is “normally significant justification for those near a proposed landfill to oppose the development of the landfill”, said the review.

 

To what extent can centralized waste collection and disposal systems help mitigate the current problems? Can such a system cope with the expected rise in the waste burden over the next few decades? And what if the central system of waste processing fails or breaks down? There is also a social factor to consider -- the livelihood of a large number of rag-pickers who now eke a living collecting and recycling wastes in large cities. They would have no place in a centralized and highly mechanized waste collection and disposal system.

 

Decentralized community-based waste management systems have an important role to play here. Such systems will encourage and support local communities to take responsibility for wastes in their areas, and involve them in reusing, recycling and economic processing of the wastes locally. This will substantially reduce the amount of waste going to the central dumps. The advantages of such community-based systems will include:

 

  • Better health and sanitation for local communities.
  • Conservation and optimum use of materials by recycling and reuse of wastes which will promote sustainable use of materials.
  • Conversion of wastes into compost and its use in home and community gardens will to some extent reduce the use of chemical fertilizers, a major contributor to global warming. Surplus compost produced by urban communities can be sold to peri-urban and rural communities for farming, again, cutting down fertilizer use.
  • Decentralized waste management will substantially reduce the need for transporting wastes over large distances, saving fuel and reducing vehicular emissions.
  • Reduction in the wastes brought to the central dump will reduce GHG emissions from the dump.
  • Handling and processing wastes at local levels will mean greater participation of local communities, greater efficiency in collection and segregation, cleaner neighbourhoods, lower costs on transport and processing, and more local employment, particularly for economically backward groups such as rag-pickers and especially poor women. Local-level waste management can also be linked with the government’s various poverty reduction and welfare measures for poor women.
  • It will substantially reduce the overall cost of waste management.
  • Finally, such a system will create awareness among communities about problems related to the environment, global warming, climate change, sustainability, etc which can push them into greater involvement in the management of such issues at local, city and national levels.

 

DECENTRALIZED COMMUNITY-BASED WASTE MANAGEMENT

 

The first step in managing urban waste is to reduce the generation of waste itself by changing our day-to-day practices, consumption patterns and lifestyles. Reusing and recycling wastes into useful products can help conserve materials and resources, leading to their optimum and sustainable use. If kitchen and other biodegradable wastes are composted and used in place of chemical fertilizers in housing society and public gardens, kitchen/terrace gardening and peri-urban farming, it would   to some extent help reduce the use of environmentally harmful chemical fertilizers. Further, the wastes can be processed to produce energy (methane and also electricity) which can be used for cooking, lighting or generating electricity, reducing the use of fossil fuels.  All these measures will not only reduce the wastes being disposed of or treated in a central dump but will have enormous benefits in terms of a cleaner environment, better sanitation and improved public health.

 

Responding to the escalating waste collection and environmental problems in the city, several groups have initiated such activities. These include housing complexes, local residents’ groups, community-based and non-government organisations (NGOs), schools and colleges, and some commercial establishments. Some of these groups segregate, reuse and recycle wastes, some process wastes into compost, and a few convert or plan to convert wastes into electricity. Some examples are briefly discussed below.

 

Reduce, reuse and recycle

Waste reduction, reuse and recycling, starting at the individual and household levels, form the most basic approach to waste management. As discussed earlier, it involves changes in lifestyles and consumption patterns which are also key components of sustainable development.

 

Many groups – individual households, local residents’ groups, NGOs and schools - are today adapting this approach. They try to reduce the waste generated at home or schools, avoiding the use of plastic bags, packaged food and other products, etc. Whatever waste is generated is first separated into “dry” ( non-biodegradable such as glass, metal, paper and cardboard) and “wet” (bio-degradable such as kitchen and market waste) wastes. Some of the dry wastes   are reused in innovative ways as, say, paper bags, greeting cards, envelopes, paperweights, and lightweight containers; the rest goes to organized recyclers. The wet wastes go to municipal dumps, or some groups convert them into compost (which is discussed later).

 

The process of reducing wastes starts at home, says the group, Are you Reducing, Reusing, Recycling (RUR), set up by five young eco-conscious women. Repelled by the piles of garbage in their neighbourhood, they first turned their own homes into “zero waste zones”, and then enlisted others into a campaign to reduce and recycle wastes. They reuse ‘wastes’ in various ways (for example, vegetable and fruit wastes for cleaning, used paper and envelopes for repacking); they make it a point to buy notebooks made of recycled paper and use cloth bags instead of plastic bags. Considering that each tonne of recycled paper not only reduces wastes but can save 17 trees, this is significant from the point of protecting the environment and cutting down GHG emissions. What is equally important is that it sets an example for children and creates awareness about these issues among them, and they tend to follow the practice, says Manisha Narke of RUR. “That’s all it takes to create future generations of green citizens”. 7

 

Segregation is crucial for reusing and recycling wastes, and several groups are engaged in this work at various levels. An example of a multiple-ward level initiative is the Bandra-Khar-Santacruz residents’ group which, in collaboration with the municipal corporation, tells residents in the area to segregate their wastes and collects about 900 kg of dry waste from them every day. The wastes are handed over to Force, an NGO, which further sorts them into five separate groups – paper, plastic, metal, glass and rubber – and sends these to recyclers. Force also collects dry wastes from various other groups, incuding RUR and sends these to recyclers.

 

Among the NGOs, Stree Mukti Sanghatana’s (SMS) Parisar Vikas, an environmental entrepreneurship programme for urban poor women, is one of the biggest programmes of waste collection and recycling in the city, involving about 2000 poor waste-picking women. Through this environmental programme, SMS also seeks to pursue several other social objectives. The women (called Parisar Bhaginis) collect wastes (mainly dry wastes), for a fee, from residential colonies, office premises and malls, and non-medical wastes from hospitals. On an average, they collect about 100 tonnes of waste a day. The segregated wastes are sent to recyclers and also converted into useful products – for example, roofing sheets made from used tetrapacks. Some housing societies have retained Parisar Bhaginis to manage wastes, including making compost, in their societies. SMS trains the women in bio-composting, vermiculture and gardening. These waste management programmes are integrated with several poverty eradication, financial assistance (for micro enterprises) and health programmes of the government. Thus this decentralised, low-cost waste management system combines “economy, empowerment of women, and the environment”, says Jyoti Mhapsekar of SMS. Parisar Vikas has achieved “near-zero waste status” in large and small housing colonies and in campuses spread over 13 municipal wards in Mumbai, and has now spread to the neighbouring areas of Navi Mumbai, Kalyan, Dombivili and Thane.8 Other NGOs who have been involved in collecting, segregating, recycling and reusing wastes in various parts of the city include Force, Aakar, Triratna Prerana Mandal, and Apnalay.

 

 

Composting and urban farming

 

Several individuals, groups and schools are converting segregated wastes to compost by different methods (vermicompost, aerobic or anaerobic composting) and use it for organic urban or peri-urban farming – growing a variety of fruits, vegetables, flowers, medicinal plants, etc in kitchen or terrace gardens or in small backyard plots. Generally, 10 kg of biodegradable waste can produce about 2.5 kg of compost. The success of some early experimenters has created enthusiasm among others, and, with the deteriorating environmental conditions in the city and rising vegetable and fruit prices, the practice seems to be catching on.

 

The 3000-square-feet lush garden on the Mumbai Port Trust’s roof is considered one of the best examples of terrace gardening in the city. Set up by Preeti Patil, the Port Trust’s catering manager, and her colleagues, the garden uses about 20 kg a day of kitchen wastes from the Trust’s central canteen, and is currently attracting attention for its productivity. The garden grows a wide range of crops, including mangoes, guavas, custard apples, strawberries, and even coconut and cotton, besides vegetables and medicinal plants. Preeti Patil has since started an NGO, Urban Leaves, to promote urban farming and conduct training programmes, and attendance is reported to have doubled from the 30 members she had when she started in 2009.

 

Not only do composting and urban farming help reduce the load on the city’s waste disposal system but they reduce expenses on food and provide some food security and also chemical-free and nutritious food. They also increase the city’s green cover (which is dwindling), promote local food consumption (which cuts down long-distance transport of food or ‘food miles’ ), and promote biodiversity (besides the diverse plants, birds, bees and squirrels are reported to be back in Preeti’s garden), all of which are important in mitigating climate change. According to urban farmers, a 600-sq.ft. garden growing six varieties of vegetables can produce up to 10 kg of vegetables every week, and an urban garden can fetch a monthly income of Rs. 4 per square foot of the garden.9 (Reflecting the growing interest in urban/terrace farming across the country, the first national seminar on urban organic terrace gardening was held in Bangalore in September 2010.)

 

The over 600 ALMs in the city also organize composting. It is estimated that about 275 composting units use up 20-25 tonnes of waste a day for composting.

 

A more broad-based waste management and farming programme by the Paryavaran Samrakshan Kendra (Centre for Environmental Protection) and the Institute for Community Organisation Research (ICOR) in Bhayander in the north of Mumbai aims to protect the local environment, create environmental awareness, reduce carbon footprint, and promote a healthy and environmentally sustainable lifestyle   in a holistic way. The programme, based in a large school, collects wastes from the school, students’ homes and the market, recycles the dry wastes and converts the wet wastes into compost which is used in a 1500-sq. ft. garden on the school terrace (and also a garden on the ground) to grow vegetables and medicinal and herbal plants. These are in turn used   to make a variety of “healthy” snacks and drinks (as an alternative to junk food and aerated drinks) for the school canteen and also cosmetic products such as natural hair oils and face-packs. Vegetable “wastes” are further processed into value-added products such as pickles. The vegetables, medicinal plants and other products are also sold in the neighbourhood. The programme involves students, teachers and parents in all   these activities. Students also get cash credits for the waste they bring to the school. “If you want to eliminate ‘wastes’ and reduce carbon footprints, you need to have a larger view of the problem, you need to look at nature and our own lifestyles in a holistic way”, emphasizes Benson George, an ardent environmentalist, who runs the programme. “Nature has no wastes, these are economic resources, and you can generate economic value from wastes”.

 

Composting wastes takes up some time, space and efforts, and if not managed well can cause some odour. This generates some resistance to composting. To avoid these problems, the market now offers handy organic waste converters, and some large housing and commercial complexes, clubs and canteens, religious establishments and agricultural produce markets are now opting for these converters. A basic 4-hp unit can convert 400 kg of waste into compost in a day, it is claimed.; the most basic unit costs about Rs. 300,000. Any surplus compost can be sold in the market. While many composters generally see lack of market for their excess compost as a constraint, Subhash Mayekar, the president of the Siddhivinayak Temple (which draws a large number of devotees and had installed a converter five years ago) says that they “have been receiving a favourable response from agriculturists who regularly buy the compost at Rs. 8 a kg”. 10 This is an encouraging sign. The BMC thinks that the converter could provide a “partial solution” to the mounting problem of waste management in the city.

 

Bio-methanation and electricity generation

 

Biodegradable wastes can also be processed into methane (biogas) which can be used for various purposes such as cooking, lighting, heating and electricity generation. Proper segregation of wastes is of course important for efficient processing. A notable effort in this direction is the development of an indigenous low-cost bio-methanation plant (anaerobic waste digester, see illustration) at the Bhabha Atomic Research Centre (BARC), Mumbai. The plant, called Nisarg-runa, segregates wastes and, using microbes, converts them into methane which is used mainly for cooking and also for heating (boilers) and producing electricity (using generators); the slurry that is left over after methanation yields nutrient-rich compost or manure. Several such plants are being used in Mumbai and in the rest of the state; some are outside the state. Altogether, about 46 such plants are in use in the country now following its introduction about a decade ago.

 

 

 

 

 

 

 

 

 

 

 

Nisarg-guna biomethanation process

 

 

Source: http://www.no-burn.org/wna07/wna2007.presentations/WNA07.Wastepickers.SMS.pdf

 

 

Nisarg-runa biogas plants – capacity, cost and output range (approximate)

Waste treatment capacity (tonnes/day)

Installation cost (Rs.lakhs*)

Monthly operational/main-tenance cost (Rs)

Methane generation (cubic metres)

Manure production (tonnes/day

Savings (in cooking fuel equivalent LPG cylinder/day and electricity in some cases

1

5-6

8,000

80-100

0.1

2-3

2

9-10

12,000

150-180

0.2

4-5

4

20-22

22,000

300

0.3

8-10

5

28-30

30,000

350

0.5

12.14/25 kW

10

65-70

50,000

700-800

2.5

22-25/50 kW

 

*Rs. 1 lakh = Rs.100,000.

Source: Adapted from “BARC Nisarg-runa plants for renewable energy”, Akshay Urja, July-August 2005, Ministry of Non-conventional Energy Sources, Government of India.

 

The plants can handle 1-10 tonnes of wastes a day. A 1-tonne per day plant can produce 80-100 cubic metres of methane and about 100 kg of manure, according to Dr. S. Kale who had developed the plant. Higher-capacity plants can generate electricity using methane. For example, a 5-tonne plant can produce 25 kW of electricity and a 10-tonne plant up to 50 kW. Considering the problems generally associated with this technology (several such plants, particularly those with large capacity, had failed earlier), Nisarg-runa plants have been performing reliably over a decade, according to a review of low-cost biogas plants in developing countries by Swiss Federal Institute of Aquatic Research.11“It is affordable,odour-free and compact, and the technology can be tailored to higher degrees of sophistication and reliability”, said the review; it leaves no garbage and effluent (“zero-garbage and zero effluent”), and provides employment to people in collecting and segregating wastes and maintaining the plants. It must be noted here that other models of efficient and low-cost waste-based bio-methanation plants have also been developed by other organizations in the country and are in use at various places.

 

In Mumbai, Nisarg-runa plants have been used by institutions, but now some residents’ groups, in association with the BMC, plan to install them in their areas to handle waste and also generate electricity for public purposes (lighting local public gardens, etc.)

 

THE WAY AHEAD

 

These are some of the examples of how different decentralized waste management systems involving households, local communities, ALMs and NGOs, working in collaboration with the municipal corporation, can supplement the municipality’s efforts and reduce the waste going to the central dumps. However, given the huge amount of waste generated in Mumbai, such efforts are, as of now, minuscule and have made hardly any impact. The total wastes handled and processed by all such groups add up to much less than 5 per cent of the total waste. These local efforts therefore need to be expanded and scaled up a great deal. However, this needs changes in the mindset of the government (which generally prefers large-scale, high-technology, centralized systems)   and in citizens’ attitude to waste, public sanitation and the environment.

 

To achieve maximum results, all the approaches to waste management discussed above, spanning various groups working at different levels, need to be integrated into a low-cost decentralized system..

 

To start with, waste generation need to be minimized both at the consumers’ as well as producers’ ends, and reuse and recycling maximized. This would require concerted public education and awareness campaigns, and a greater emphasis on waste reduction, reuse, recycling and in general sustainability in the municipality’s waste management system. A system of price incentives can encourage consumers to use more recycled products. At the same time, manufacturers should be made to take responsibility for their full product cycle, like recalling packages for reuse or reprocessing. (The use of plastics particularly needs to be drastically curbed or, in the case of some types of plastics, eliminated though the plastics industry has been resisting all such moves.) It must be noted that most good waste management systems in industrialized countries are built up on maximum recycling. The BMC now plans to enforce waste segregation at household levels which may lead to greater reuse and recycling. But the municipality should also improve the efficiency of waste collection.

 

Community-level composting is a proven method of managing biodegradable wastes, and should be encouraged and supported by the municipal corporation. Limitations can come from the nature of the contents (mixed contents and toxic materials) of the waste and the operational conditions. So careful segregation is important, and so also proper maintenance. The municipality and NGOs therefore need to provide good training in composting. The compost can be used for urban farming, but markets for excess compost need to be explored which will encourage more groups to go in for composting wastes.

 

Beyond composting, bio-methanation offers a good option for decentralized waste management in a city like Mumbai. The city has 25 wards, and two medium-sized bio-methanation plants in each ward can take care of a great deal of wastes, besides providing energy, nutrient-rich manure and some employment to the local people, and reducing waste transport cost to a great extent. However, proper training, operation and management of the plants are important as many such plants have failed because of operational problems. Plant size is also important because very- high-capacity   bio-methanation plants are prone to failure as shown by experience elsewhere in the country.

 

As seen earlier, 20 per cent of the city’s waste is recyclable and 50 per cent biodegradable.

This indicates the extent to which wastes can be eliminated or, to see it in   another   perspective, the extent to which resources can be conserved and generated if all the above methods of waste management can be combined into an effective system, involving people at all levels – from households and housing societies to local areas, wards and the municipality.

 

 

References

 

  1. Singhal, Shaleen and Suneel Pandey. “ Solid waste management in India: status and future directions”, TERI   Information Monitor on Environmental Science, The Energy Research Institute, New Delhi, 2001
  2. Viju, B and Sharad Vyas. “Clock’s ticking as Mumbai struggles to dispose of waste”, The Times of India, Mumbai, 5 June 2011
  3. Pradhan, Kunal and       Chandrima Pal. “Binned there, dumped that”, Mumbai Mirror, Mumbai, 28 August 2010
  4. Vyas, Sharad. “BMC dreams of huge carbon credits from Deonar in the dumps”, The Times of India, Mumbai, 27 December 2010
  5. Department of Environment, Food and Rural Affairs, UK. “Review of environmental and health effects of waste management : municipal solid waste and similar wastes, UK (early 2000s). http://www.defra.gov.uk
  6. Lee,       Fred G. and Anne Jones-Lee. “Flawed technology of Subtitle D. Landfilling of municipal solid waste”, G. Fred Lee and Associates, USA, 2008
  7. Ratnam, Dhamini. “Trying not to spill the bins”, The Hindustan Times, Mumbai, 5 June 2010
  8. Mhapsekar, Jyoti. “Environmental entrepreneurship programme for urban poor women”, Urdhva Mela, vol. 5, no.1, Mumbai, 2008
  9. Mitra, Smita. “Radish on the rooftop – city farms are changing the urban landscape and growing food for the home too”, Outlook, 25 October 2010
  10. Vyas, Sharad. “Garbage to compost: buildings invest in waste converters”, The Times of India , Mumbai, 22 May 2010
  11. Muller, Christian.       “Anaerobic digestion of biodegradable solid waste in low- and middle-income countries”, Eawag (Federal Institute of Aquatic Research), Switzerland, 2007

 

Report by K. Prabhakar Nair

Climate Change - What has el nino got to do with it?
Adaptation – and mitigation happens; and so does food security!
The UNFCCC COPs and India
Earth spirituality - a new eco-social paradigm
Reflections
                                      past issues