INTRODUCTION

Carbon footprint refers to the total amount of carbon dioxide and methane  emitted due to the various anthropogenic sources.Methane is regarded as an important source of global warming with the warming potential (GWP) of 25 times greater than that of carbon dioxide and concentration of atmospheric methane is increasing in the range of 1-2% yearly (Sunil et al., 2004; IPCC 1996; Mohammed et al, 2009).Improper management of municipal solid waste constitutea potent GHGand hence plays a significant role in carbon footprint of urban society at local level (Ramachandra and Shwetmala, 2012).

Solid waste generated in municipality is commonly known as garbage consists of degradableand non-degradablewaste materials (ex: food scraps,product packaging, grass clippings, furniture, clothing, bottles, paper, appliances) produced in the society by various domestic activities. It comprises similar and dissimilar accumulation of wastes from urban, agricultural, industrial and mineral wastes. Residential solid waste refers to wastes from houses, apartments consists of leftover food , vegetable peel, plastic, clothes, ashes, glass, metal, paper etc., (Ramachandra 2006).The percentage of carbon dioxide and methane varies according to the waste composition, age, quantity, moisture content and ratio of hydrogen/oxygen availability at the time of decomposition, (Arvind et al., 2008).Emission of methane from landfill accounted 3-9% of the anthropogenic source in the world (IPCC, 1996; Sunil 2004).

Rapid urbanization, industrialization, raised standard of living and change in the pattern of consumption, etc. have enhanced the generation of solid waste and its management has become the major problem in municipalities throughout the world (Seo et al., 2004; Issam 2010). The unscientific management and disposal of solid waste in urban cities have resulted in the adverse effects on public health risks(ex: disease vectors, files, mosquitoes, roaches, rodents), environment such as air, water and land pollution and unaesthetic appearance. Moreover, Municipal solid waste is a vital source of anthropogenic greenhouse gas (GHG) emissions such as methane (CH4), biogenic carbon dioxide (CO2) and non-methane volatile organic compounds (NMVOCs), etc. (Ramachandra 2006; Nguyen Phuc 2010).

MUNICIPAL WASTE MANAGEMENT PRACTICES IN BANGALORE: AN OVERVIEW

Greater Bangalore known as the garden city in early 1970’s, is the fifth metropolis city of India (Ramachandra and Uttam, 2010). Population of Bangalore city has increased from 6,537,124 (2001) to 95,88,910 (2011) (http://censuskarnataka.gov.in). Bangalore has grown spatially more than ten times (from 69 to 741 sq.kms) since 1949-2007.The city is facing severe shortage of landfills to dump garbage due to the enormous urbanization, affluence,steep increase inthe necessity of the Information Technology (IT) sectors and community standard of living. Bruhat Bangalore MahanagaraPalike(BBMP) is responsible for management of solid waste and to set up the targets and objectives in the city. The city has been divided into 30 ranges and 198 revenue wards for administrative purposes including the management of solid waste, health, etc. Further these revenue wards are divided into 294 health wards for the proper management of the sanitation functions. Out of these 113 are managed by BMMP, while 182 wards managed by the private agencies on contract basis (Ramachandra and Shruthi, 2007; Sudhira et al., 2007).
InBangalore,Municipal solid waste originates from Domestic (55%), Markets (15%), Hotels and eatery (20%), trade and commercial (6%), Slums (1%) and Street sweeping and parks (3%).The composition of the waste generated at the residences level as well as the city level has changed over the last two decades. Table 1 shows the composition of MSW generation of Bangalore.Residence 9household wastes) is the major contributor of the total wastes and it is distinguished by a high content of organic waste(72%).The total Municipal Solid Waste has increased from 650 tpd (1988) to 1450 tpd (2000) and about 3600 (2010) tons per day (tpd) with a per capita generation from 0.16 kg/d (1988) to 0.58 kg/d (2009). Presently, a quasi-centralized collection system is employed in Bangalore. The waste collection system from households (HH) closely follows the Municipal solid waste (handling and management) MSW (H&M) Rules 2000, employing door-to-door collection. In most of residential area the provision of dustbin is removed to avoid the multiple handling of waste(Chanakya et al., 2010; TIDE, 2000).

Table1. Composition of MSW generation in Bangalore

During the early stages, a large part of the city wastes were sent to a compost plant operated efficiently by KCDC (Karnataka Compost Development Corporation)situated outside the city limits.  In late 80’s the city wasproducingabout 650tpd of waste and among this, about 100 tpd of market wastes (vegetable) were taken back for direct application on the land and another 150 tpd was handled by KCDC. A large portion of decomposable waste was ‘open dumped’ along with various arterial roads at outskirts of the city (Rajabapaiah 1988). This trend of open dumping continued till 1999-2000. Today as the wastes generated has increased drastically, city wastes are being openly dumped at about 60 known dumping sites and many unrecorded sites. Existing solid waste treatment system in the city is not well-organised as composting accounts for 3.14%, but with increase in urban solid waste, the compost plants have not increased. Among these, more than 35 sites possess a mixture of domestic and industrial waste (Lakshmikantha, 2006). Due to the open dumping of large quantum of untreated waste there are serious implications on the land, water and air environment including public health.

The main objective of this study is to assess theCO2 equivalent emissionfrom the household solid waste. This includes determination of total and per capita waste generation and itscomposition, in household sector of Bangalore.This has been done through compilation of data by stratified random survey of households using the structured questionnaire. The data collection and analysis at local level helps in  understanding the waste dynamics for environmentally sound management of solid waste through planning of appropriate treatment options and its infrastructure.