Introduction

Bangalore city, one among the five metros in India, produces about 3600 tons per day (tpd) of municipal solid wastes (MSW).  A major constituent (72%) of this is organic waste. Presently, Bangalore employs a quasi-centralized collection system coupled with generally an open-to-sky compost based processing and subsequent landfill based disposal.  The collection and transportation systems are functioning quite satisfactory.  This does not allow accumulation of wastes near residential areas or street corners.  The waste collection system from house holds (HH) closely follows the Municipal solid waste (handling and management) MSW (H&M) Rules 2000, employing a variety of small powered and non-powered vehicles for direct door-to-door collection of wastes.  The extent of wastes collected ranges from 75-90% of the total wastes generated.  In order to avoid the multiple handling of wastes, the State Government has removed most of the open bins in residential areas.  Residents now hand over wastes directly to collection workers.  It also restricts accumulation of waste near residential area or near street corners.  Informal sector for recycling is also quite active in Bangalore and is responsible for collecting the recyclables from open bins (wherever present), other collection systems and from dumping and /or processing sites.  A few of these recyclers also purchase the recyclables from individual households.  In this way, the informal sector, in various forms, is reported to be actively recovering the recyclable wastes without too much of Government interference (Van, 1994).  However, earlier, when wastes were dumped by households in street bins, it provided a good opportunity for rag-pickers to recover most of the recyclables (Chanakya and Sharatchandra, 2005).  It is also important that a decentralized and economically viable processing and management system is required for fermentable components of the MSW in order to be sustainable in the long run.  In Bangalore, the informal sector does not participate in collection, processing or recycling of organic waste components as reported for many other urban or peri urban cities of Karnataka (Nunan, 2000).  It has been reported that till recently, about 60% of the MSW collected was dumped at about 60 known and unknown (unrecorded) dumping sites around Bangalore.  Further, among these more than 35 sites received a mixture of domestic and industrial waste (Lakshmikantha, 2006).  As Bangalore is rapidly complying with the MSW (H&M) 2000 rules, a large fraction of the MSW is reaching designated “integrated processing and landfill sites” around Bangalore.

Citizen, resident welfare associations (RWA) and non-governmental organizations (NGO) have in the past set up many small scale processing and treatment units. These small scale collection, treatment and processing units have over two decades achieved different levels of success of motivational (information, education and communication, IEC) activities.  The city of Bangalore has a rich experience in decentralized, resident association, Non Government Organization (NGO) and other forms of small initiatives at resident locality based treatment and processing of MSW.  The Bangalore city corporation (Urban Local Body, ULB) – Bruhat Bangalore Mahanagar Palike (BBMP) has been interested and supportive or supporting these small scale efforts in many ways in the past.  It supports private and NGO initiatives as a way of expanding its own waste services throughout the city. A systematic waste management requires an active approach of ULBs along with public participation.  In large metropolitan area (with a population of 1 million or more), it is difficult to have meaningful public participation, a decentralized system is needed to stimulate more active people’s participation (Appasamy, 1994).  In some of the latest trials, attempts have been made to carry out decentralized waste treatment by rapid aerobic composting with some degree of success (Subramanya, 2009, per. comm.) coupled to recovery, processing and sale of recyclables.  Several small scale efforts have been tried to reduce the pressure on transportation of wastes from localities where they have been generated.  Several resident welfare based organizations have in the past attempted to process MSW within the locality of its generation and the most recent one has been the Yelahanka New Town facility.  This comprises of a primary segregation system that removes a lot of the recyclables and leaves behind the fermentables that is composted in 50 kg lots.  The plastics (LDPE/HDPE) are washed with hot water, dried and melted into slabs and finally sent for re-forming or recycling.  Composting as the main method for rendering acceptable the fermentable fraction of USW, especially in the residential areas, does not yield high throughputs for successful enterprises.  Common factor among all of these systems has been the drive from the residents to keep their locality aesthetically and environmentally clean – usually anchored by a few elderly or retired personnel.  Another feature of these systems has been a rather ephemeral period of successful operation. Most of these systems have functioned for a specific period because of the inspiration of a few in the locality and propped up due to a sense of civic responsibility among these few.  With passing age and difficulty in sustaining the initial zeal at a latter period, these initiatives have often reverted to the conventional, government run /mediated collection and disposal systems.  The city of Bangalore is replete with such examples.  In most of the cases economic sustainability or political will have been the weak link because of which such good efforts have come to a naught.  A model that could then survive not merely on society’s endogenous drive but also possesses economic and political sustainability – is of great importance.

Today we know that there are several small localities willing to operate decentralized MSW processing and treatment systems.  Having established this fact, we attempt to examine the various combinations of costs and income sources that can be made financially and commercially viable /sustainable.  Crucial to this has been the recent introduction of small scale biomethanation as a revenue generation option that removes the menace of odour and fly nuisance associated with aerobic composting attempts (Chanakya et al, 2009; Rahman et al, 2009).  We attempt to show that such a combination would not only make decentralized MSW processing and treatment sustainable, it will also greatly reduce the costs of SWM transport at the city level and will pave way for many small entrepreneurs to carry out decentralized processing facilities and be economically, environmentally and socially sustainable.