Solid Wastes in India pose a formidable challenge to urban managers today and it is roughly estimated that the country produces 30 million tonnes of urban solid waste annually (GOI, 1998). Share of urban population in country's total population is about 27 percent and per capita waste varies between 0.1 kg and 0.6 kg per day, with an average of 0.33 kg (Bhide, 1990).  Prevailing management strategies are inefficient, because of its complexity, cost and lack of technology, and then ignore solid waste management's socio-economic and ecological characteristics.  Improper management of these wastes leads to public health hazards, unaesthetic appearance, pollution of soil and water sources such as lakes, groundwater sources, etc.  Most parts of India are inefficient in handling wastes in terms of lack of stakeholder participation and inadequate organizational framework.  In order to improve the present practice and to avoid environmental degradation, an effort is made in this study to arrive at optimal solid waste management strategy as applicable to developing countries using a prototype model, which represents a typical urban system.  With the help of identification of problems and analysis of those problems, optimal management strategies include effective implementation of all essential aspects of urban solidwaste management.  Spatial and temporal analyses tools such as Geographic Information System (GIS) and Remote sensing data are of immense help in this regard.
Indian Institute of Science (IISc) campus, Bangalore, India was chosen for developing a feasible solid waste management model. IISc campus represents a cosmopolitan urban set up and the model developed for the campus can be replicated in any urban area in developing countries.  Quantification of various wastes from different sectors through field investigations covering collection mechanisms, primary constituents, rates of generation, etc. were carried out. Apart from this, litter generated in vegetated area has been quantified through landuse analysis using field and remote sensing data. 
Land cover analyses reveal that about 45% of the total area is under tree vegetation.  Stratified random sampling strategy is adopted in order to quantify the litter produced in the campus through regular monitoring of study plots of 1 sq.m spread all over campus.  Based on detailed field observations, strategies for quantification to arrive at the precise quantity of waste generated (attribute information), and effective use of GIS (various layers of spatial information) and optimal management strategy of all kinds of wastes is proposed.  The management options are proposed with the help of available guidelines from literature, which were synthesized and modified according to the prevailing conditions. The proposed management strategy could be implemented in urban pockets irrespective of geographical area and population.                        

From the days of primitive society, humans and animals have used the resources of the earth to support life and to dispose wastes.  In those days, the disposal of human and other wastes did not pose significant problems as the population was very small and the area of land available for the assimilation of such wastes was large.  However, today, serious consideration is being given everywhere to this burgeoning problem of solid wastes. Rapid population growth and uncontrolled industrial development are seriously degrading the urban and semi-urban environment in many of the world's developing countries, placing enormous strain on natural resources and undermining efficient and sustainable development.

The purpose of the Solid Waste Management (SWM) exercise is to help improve poor practices of SWM that prevail in many low income countries where this subject has received scant attention compared to other aspects of infrastructure such as water supply and transport.  It is a multi-disciplinary field embracing waste collection, transfer, haulage and disposal and its impact is wide.  It is therefore important to take a broad view and not to consider disposal options within the narrow confines of a particular technology.  This work is formulated from the available literature and gives particular emphasis to the principle of building on existing capacity of waste managing authorities.

An effort was made to study and suggest improved SWM practice for an area of about 180 hectares (Indian Institute of Science, Bangalore) whose waste generation resembles a typical urban community, equivalent to a ward under city corporation's jurisdiction.  The proposed strategies can be replicated in large communities and townships.  Optimal SWM strategies for many kinds of wastes are proposed effectively with the help of field investigations and spatial analysis tools (Geographic Information System, GIS), constituting a framework for efficient planning for waste management. Suggestions involving source segregation, designing collection systems, recycling and reuse (usage of organic wastes for production of biogas and fertilizer), optimal routing of collection vehicles, appropriate design of community bins, effective stakeholder participation, hazardous waste management, safe disposal options, etc have been proposed.

Any solid material in the material flow pattern that is rejected by society is called solid waste.  Solid wastes arise from human and animal activities that are normally discarded as useless or unwanted.  In other words, solid wastes may be defined as the organic and inorganic waste materials produced by various activities of the society and which have lost their value to the first user.  As the result of rapid increase in production and consumption, urban society rejects and generates solid material regularly which leads to considerable increase in the volume of waste generated from several sources such as, domestic wastes, commercial wastes, institutional wastes and industrial wastes of most diverse categories.   Wastes that arise from a typical urban society comprises of garbage (Refer Annexure 1 for definitions), rubbish (package materials), construction and demolition wastes, leaf litter, hazardous wastes, etc.

Management of solid waste may be defined as that discipline associated with the control of generation, storage, collection, transfer and transport, processing, and disposal of solid wastes in a manner that is in accord with the best principles of public health, economics, engineering, conservation, aesthetics, and other environmental considerations.  In its scope, solid waste management includes all administrative, financial, legal, planning, and engineering functions involved in the whole spectrum of solutions to problems of solid wastes thrust upon the community by its inhabitants (Tchobanaglous, G. et al, 1997)

To implement proper waste management, various aspects have to be considered such as

• source reduction
• onsite storage
• collection and transfer
• processing techniques
• disposal

The following flow chart shows the interrelationship between the functional elements in solid waste management.

 

   

The day to day management of solid wastes is a complex and expensive activity. Disposal functions have to be sought for the future, the overall objective being to minimize the adverse environmental effects caused by the indiscriminate disposal of solid wastes. This is of paramount importance to health, environmental protection, natural resources management and sustainable development.  Developed countries have adopted sophisticated management practices.  Imparting the same in low-income countries is not economically, and technically viable and socially acceptable. However, the management strategies that are to be adopted for low-income countries should ensure maximum safety to the environment.

Management objectives: Management strategies should be in such a way as to perform the following functions

Potential hazards of solid wastes are numerous to the living community when it is improperly managed. Solid wastes have the potential to pollute all the vital components of living environment (i.e., air, land and water).  Some of the hazards caused by solid wastes are listed below, (Mansoor Ali et al, 1999).

Poor management of Solid waste is a bane of urban society.  The problem is severe in urban areas because, people from rural area are migrating at an alarming rate for want of employment and better quality of life.  Absence of proper municipal amenities adds to the existing menace.  Whenever there are sudden surges of population, municipal authorities are forced to take ad-hoc measures, which compound the problem further.  The situation should be turned over for good and it needs an organized and well-thought out approach. In short, the major causes of this dilemma are,

Despite a large body of work on high technology options for waste disposal, there is very little material appropriate for low-income countries.  It is observed that inappropriate, expensive and unmanageable disposal systems are being implemented in many places.  Numerous technologies / options are available in SWM, among developed countries.  Replicating the same in low-income countries is inappropriate / incompatible.  The success of waste disposal practices depends largely on overcoming the following constraints,

• MUNICIPAL CAPACITY: The scale of task is enormous and regulatory authorities are able to collect only 60-70% of total waste generated (UNCHS 1994), so treatment and disposal inevitably receives less attention.  Attempts are being made in a few instances to overcome this lack of capacity by privatizing this operation. 
• POLITICAL COMMITMENTS: Solid waste management is much more than a technical issues; it has implications for local taxation, employment, and regulation of public and managing authorities. Any change needs political support to be effective.  However, it is rarely a priority for political concerns unless there is strong and active public interest.  This is viewed as a cost to the "public" without apparent returns.
• FINANCE, COST RECOVERY AND RESOURCE CONSTRAINTS: Deployment of a proper management system represents a major investment and it may be difficult to give it priority over other resource demands.  Most of the waste management authorities are severely constrained by the lack of resource to finance their services.  Since the collection and transport itself usually dominate SWM costs in developing countries, safe disposal invariably receives less attention where as in all other developed countries concentrate on all aspects of management.
• TECHNICAL GUIDELINES: Standards of planning and implementation in high-income countries may not be appropriate in low-income countries due to difference in climate, resource, institutions, attitude priorities, etc. However, relatively little appropriate guidance is available for low-income countries.  Arising from this uncertainty, officials find themselves ill equipped to plan management strategies, which are both achievable and avoid unacceptable environmental hazards.
• INSTITUTIONAL RESPONSIBILITIES: Though managing wastes effectively is the responsibility of the municipality, there is no clearly stated vision of management (i.e. sufficient priority is not given to SWM).  Existing vision is accompanied by a typical apathy to solid waste is an "out of sight is out of mind" attitude by the municipalities and public because of strict rule and regulations are not implemented just like as in prevention of emission of water and air pollutants.  Waste management necessities the co-ordination of all authorities concerned and may involve departments that are accustomed to acting independently but the lack of accountability in all levels of management. Among the authorities, the roles and responsibilities of different departments need to be clearly defined and accepted by all concerned. Some smaller towns may not have staff with specific responsibility for providing a solid waste management service.
• INADEQUATE LEGAL PROVISIONS: In most countries, the laws and regulations on solid waste management are outmoded and fragmented and hence are inadequate to deal effectively with the modern complications of managing wastes in large cities.  Most of the laws deal with the general tidiness of the city streets, waste collection and their disposal at places away from settlements.  Even these inadequate laws are not fully enforced.  This aggravates the situation further.

Solid waste management is a civic problem and it has to evolve optimally and continuously to serve the future generation.  Solid wastes if unchecked can not only be a health hazard but will impart multidimensional threats, which include serious detrimental, environmental, social, and economic impacts.  Solid waste management in developing countries is a complex issue as the types of wastes generated vary widely because of the varying localities with diverse populations. The boundaries of the analysis of the "waste problem" are difficult to define. A complete and environmentally sound SWM requires effective contribution from all those who are involved in this problem.  Everyone is part of the solid waste generation problem and everyone shall also be part of the solution of proper management i.e., solution depends upon collective human action and efforts.

The trend of unsustainable patterns of production and consumption is increasing the quantity of the waste and the amount will increase four to fivefold by the year 2025 (Earth Summit-1992).  As many as 5.2 million people, including 4 million children under five years of age, die each year from waste related diseases. The health impacts are particularly severe for urban poor.  At present over 2 billion people will be without access to basic sanitation, and an estimated half of the urban population in developing countries is without adequate solid waste disposal services.  Solid waste management operations currently absorb 30 to 50 percent of the municipal operating budgets in developing countries (Earth Summit-1992).  Some of them have experienced a six-fold increase in solid waste disposal costs over the last decade.  The costs are likely to double or treble by early next century.  For these reasons, solid waste recycling and reuse has attracted considerable attention worldwide and numerous action plans to promote sustainable human settlement development focussing on environmentally sound management of solid waste have been initiated.  Such actions call for an integrated approach to solid waste management.

The importance of proper solid waste management is one of the prime functions of the civic body, as insanitary management of solid wastes is a cause of much discomfort.  Since waste management is the fundamental requirement for public health, Article 48-A of the Indian Constitution establishes the responsibility of the state to manage these wastes properly.  On the basis of available data, it is estimated that the nine major metropolitan centres in India are presently producing 23,000 tones of solid waste per day.  As per recent estimates, Bangalore generates about 3,600 tonnes per day and the following table provides comparative details about garbage generated and cleared in nine major Indian cities (IIED, 1999).
Urban waste situation in some major Indian cities are:

        Source: India Today, 31st October, 1994

In most cities, the municipal service for the collection and transportation of urban solid wastes comprises three separate functions as follows,

Indian waste management system is starved of resources to tackle the increasing demands associated with growing urbanisation.  Due to budgetary constraints, inadequate equipment and poor planning, house-to-house collection is very rare in India, particularly in certain low-income areas where waste is not collected at all.  It is estimated that upto 30-40 percent (UNCHS, 1994) of disposed solid wastes are left uncollected.  The areas, which are not serviced, are left with clogged sewers and litter which, create serious health problems for the resident population.

Storage of wastes before final disposal is done at three levels:

• At source: Solid wastes are often stored at the source until they are picked up by waste collectors (collection crew) or taken out to be thrown into an open space or a community bin.
• At community level: Community bins are used in crowded and narrow market areas, which is a common feature of most developing countries.  Because of the high cost of door to door collection many waste management authorities have introduced community bins.
• At transfer stations: Transfer stations are established, for economic reasons in cities, which have long haulage distances to final disposal sites.  Smaller collection vehicles bring in the wastes collected at their source of generation or from the community bins and larger vehicles transport them away to final disposal sites.  Transfer stations are also used as collection and sorting points for recycling materials.

Most of the collection systems followed in India are:
Door to door collection: This system is used in narrow streets where a collection truck cannot reach individual houses.  The house places the filled containers outside their doors when the waste collectors arrive.  Some cities such as Chennai (Madras) and Chandigarh have implemented this in posh localities where influential people reside.  On similar lines, Bangalore City Corporation (BCC) recently introduced door to door collection in some wards and management seems to be satisfactory.
Curbside collection: This method is used in wider streets, where the collection trucks can pass through conveniently.  The house owners leave the waste containers at the edge of the pavement.  The waste collectors collect the waste from the curbside or empty the containers into the vehicle as it passes through the street at a set time and day and return the containers as practiced in Kanpur (UNCHS, 1994).
Block collection: The collection vehicles arrive at a particular place or a set day and time to collect waste from the households.  Households bring their waste containers and empty directly into the vehicle (UNCHS, 1994).
Community bins: Community storage bins are placed at convenient locations, where the community members carry their waste and throw it. (These bins are also called Delhi bins, since it was introduced first time in Delhi)

Collection Methods   Sustainability Indicators	Door to Door Collection	Curbside Collection	Block Collection	Community Bins
Area improvement	√	√	√	Х
Convenience of the people	√	Х	Х	Х
Convenience of the staff	Х	√	√	√
Handling the extra waste during festival	Х	√	√	√
Frequency and Reliability	Х	√	Х	√

The phenomenon of recycling by means of repair, reprocessing, and reuse of waste materials is a common practice in India.  At the household level recycling is very common.  Waste is accessible to waste pickers; they segregate it into saleable materials such as paper, plastics, glasses, metal pieces, textile, etc.  Rag pickers segregate the wastes directly from the dumps and bins with no precautions and they are exposed directly to harmful wastes.  The separated waste is sold to a small waste dealer, from where the waste is transferred to a medium sized dealer or wholesaler.  All these activities are not regulated or monitored by any governmental organisation.  Due to this informal segregation, volume reduction is achieved, while it ignores social, economic, environmental, and health aspects

2.6  treatment and  treatment options

Waste collected by the formal and informal sectors is delivered mainly to three destinations. The remaining waste goes for disposal.  First, high quality materials and used products are cleaned or transformed for reuse.  A well-known example is the reuse of old newspapers for packaging material.  Second, recyclable materials are traded for recycling purposes.  As a result, a wide range of products is generated.  Third, organic waste can be converted into compost, which, when used as manure instead of chemical fertilizer contributes to improved fertility of the soil.
Recycling & Reuse: The processes, by which materials otherwise destined for disposal are collected, reprocessed or remanufactured and are reused. Annexure 3 gives the list of commonly separated recyclable components in the municipal waste stream in India.  The separation for recycling takes place at households, community bins, open dumps and even in final disposal yards.  The recycling business is a complicated chain of operations and varies from place to place.  The recycling and reuse (the use of a product more than once in its same form for the same or another purpose) sector of waste management in cities of Asian developing countries is potentially high. Its economic assessment is a difficult task since it is practiced in an informal manner.
Biogas: Biogas contains approximately 60:40 mixture of methane (CH4), and carbon dioxide (CO2) produced by the anaerobic fermentation of cellulose biomass materials - simultaneously generating an enriched sludge fertilizer - with an energy content of 22.5 MJ/m3, clean gaseous fuel for cooking, for running engines for shaft and electrical power generation with little or no pollution.  Many cellulose biomass materials are available in urban and rural solid wastes and may be utilized to produce eco-friendly renewable energy, contributing to the clean waste management.  In India, biogas production is currently practiced in many places in rural areas (with cattle dung) and few places in urban areas (with sewage).  

Waste disposal options
Final destination of solid waste in India is disposal.  Most urban solid waste in Indian cities and towns is landfilled and dumped.  A wide range of disposal options in many developing countries is available and some of them are listed below,
Non-engineered disposal: This is the most common method of disposal in low-income countries, which have no control, or with only slight or moderate controls.  They tend to remain for longer time and environmental degradation could be high, include mosquito, rodent and fly breeding, air, and water pollution, and degrading of the land.
Sanitary landfilling: Sanitary landfill is a fully engineered disposal option, which avoids harmful effects of uncontrolled dumping by spreading, compacting and covering the wasteland that has been carefully engineered before use.  Through proper site selection, preparation and management, operators can minimize the effects of leachates (polluted water which flows from a landfill) and gas production both in the present and in the future.  This option is suitable when the land is available at an affordable price.  Human and technical resources available are to operate and manage the site.
Composting: Composting is a biological process of decomposition carried out under controlled conditions of ventilation, temperature, moisture and organisms in the waste themselves that convert waste into humus-like material by acting on the organic portion of the solid waste.  If carried out effectively, the final product is stable, odour-free, does not attract flies and is a good soil conditioner.  Composting is considered when biodegradable waste is available in considerable fraction in the waste stream and there is use or market for compost. Centralised composting plant for sector may only be undertaken if adequate skilled manpower and equipment are available, hence at household level and small level composting practices could be effective which needs the people's awareness.
Incineration: Incineration is the controlled burning of waste in a purpose built facility. The process sterilizes and stabilizes the waste.  For most wastes, it will reduce its volume to less than a quarter of the original.  Most of the combustible material is converted into carbon dioxide and ash.   An extensive sample programme conducted in India (Bhide and Sundaresan, 1984) reveals that most of the waste had a calorific value of just 3350 joules/g compared with 9200 joules/g in high income countries.  Incineration may be used as a disposal option, only when landfilling is not possible and the waste composition is of high combustible (ie self-sustaining combustible matter which saves the energy needed to maintain the combustion) paper or plastics. It requires an appropriate technology, infrastructure, and skilled manpower to operate and maintain the plant.  In Indian cities, Incineration is generally limited to hospital and other biological wastes and mostly others are either landfilled or dumped.
Composition of urban solid waste in Indian cities (% by weight)

Source: Planning commission on "Urban Solid waste Management in India", GOI (1995)
*Includes rubber and leather
**Includes bones, stones and woody matter
This data clearly shows that compositions of Indian waste stream collected from garbage bins are mainly of low calorific value with high moisture content. Hence, due to non-combustibility, Indian city waste is not suitable for incineration (Rajabapaiah, 1995).
Main objective of disposal options is to ensure maximum safety to the environment. Imparting processing techniques such as Gasification, Refuse derived fuel (RDF), Pyrolysis etc., require administrative, technical, political, social and economic support.

*Incineration with energy recovery

3.1 SIGNIFICANCE OF INTEGRATED  APPROACH
Management of municipal waste to be effective requires an integrated approach involving components such as source reduction, recycle, reuse, incineration, etc.

The best management practice does not rely on a single processing technique and disposal option, since merit and demerits associated with all prevailing techniques.  Final strategy needs to combine various techniques depending upon the constituents in the waste stream. Healthy environment demands an integrated approach that involves complementary use of a variety of practices to handle the solid waste stream safely and effectively with the least adverse impact on human health and the environment.  Hence, planning (by various level of government and waste management industry) to be effective has to address the current and future problems faced by the communities and manage municipal solid waste in a safe and efficient way. An integrated approach (EPA, Solid waste dilemma, 1989) for waste management consists of some or all of the following components,

Management practices have to match particular waste stream constituents and select those that are best suited, in order to reduce toxins and quantity and safely extract useful energy or material prior to final disposal.

Environmentally sound management goes beyond the mere safe disposal or recovery of wastes that are generated and seeks to address the root cause of the problem by attempting to change unsustainable patterns of production and consumption.  This implies the application of the integrated life cycle management concept, which presents a unique opportunity to reconcile development with environmental protection.  United Nations Centre for Human Settlements (UNCHS, 1994) emphasizes on the following four programme areas, which will vary according to the local socio-economic and physical conditions, rates of waste generation and waste composition. 

To accomplish these, the management strategies are required to focus on the following:

1. Increase the waste planning and management information (both technical and educational) available to states, local communities, waste handlers, citizens and industry, and increase data collection for research and development.
2. Increase effective planning by waste handlers, local communities and states.
3. Increase recycling by government and by individual and corporate citizens.
4. Increase source reduction activities by the manufacturing industries, government and citizens.
5. Reduce the risk from municipal solid waste combustion in order to protect human health and the environment.
6. Reduce risks from disposal facilities in order to protect human health and the environment.

Fulfilling these aspects helps in overcoming constraints such as, increased waste generation rates and concerns over human health and environment.

The overall framework needed for the effective solid waste management is illustrated in the above chart. 
The integration of all components present takes place at various levels to arrive at feasible management.  All components of this framework are intended towards the key aspects of SWM, which are

Technical aspects include the following issues:

3.4 STAKEHOLDERS PARTICIPATION

The critical element is the consultation of common goals and implementation involving all stakeholders. Owning and identifying with the system and its components role is substantial which influence contemporary project design and sustainable management.  The common factors that influence non-effective stakeholder participation are as follows,

Collaboration with all stakeholders, especially with waste generating agents is very crucial, implying integration between the formal and informal recycling agents.  For example, the segregation of household waste at source would reduce the burden significantly. Stakeholder participation helps in achieving segregation at source and improves the recycling and reuse of wastes. Appropriate incentive helps in effective participation by stakeholders.

motivating the public to support the solid waste management program, which includes diverse culture, range of human mentalities and thoughts, requires interpersonal approach. Public education programmes aid in

• Explaining the necessity of public  participation
• Raising awareness about waste management needs and concepts
• Advocating adoption of the desired waste management system /attitude.

Policy interventions are possible through active participation of the public. Public education and incentives would help in this regard. Public awareness also helps immensely in lobbying to ensure the government machinery implement the decided management plans.
Several stages of public education are:
awareness:  Information about solid waste, health hazards, necessity for feasible management, role of public in management and optimal management strategies. Program planners through variety of methods explain the program in effective manner.
INTEREST: After people have been made aware of waste management issues, they seek more information. Public education helps in answering the queries and provides more information.
TRIAL: Participants and individuals try the programs at this stage and this proves to be very decisive. An adequately staffed and properly trained clearinghouse or hot line is a useful tool to answer questions and provide additional information.
EVALUATION: Participation increases when program requirements are easy to follow.  At this stage individuals decide whether to participate or not.  For even well promoted programs, initial participation is about 50%.  Periodical evaluation and monitoring help in streamlining program requirements and in further improvement.
ADOPTION: Education components in the program usually focus on reinforcing program participation.  Ongoing education programs solicit constructive feed back and provide new program information when necessary. Public support and participation would continue to grow for well thought out and implemented programs. This helps in adoption of management practices.
MAINTENANCE AND ADAPTATION: Incentives and education while keeping participation rates high also help in maintaining the system thereby ensuring long term sustainability.  Users adapt the system to their convenience. 

The effective waste management is a continuing process of public education, involvement, implementation and evaluation.  Among these, key issue is wholehearted public participation, which has to face several interwoven components:
PEOPLES' Concerns: People concerns about waste management which include costs, aesthetics, odour, littering,  social issues of handling etc. have to be put on the public agenda, which fascinates the public involvement there by effecting the management methods.
Involvement: Representatives of various interest groups (regulatory officials, individuals from neighboring communities, local waste management experts, stakeholders, representatives from environmental and business groups) are to be encouraged to participate.  Bringing representatives of interest groups together and providing a forum for communication is an important need for long-term sustainability of the program.
Issue resolution: Interest groups make their points of agreement and disagreement clear to each other and to program planners.  The various groups then attempt to understand and resolve points of conflict, which is the most important issue for the sustainability of practice adopted.
Alternatives: Participants make a list of available alternatives, including taking no action.  At this stage participants may use the different criteria to analyse comparative economics, environmental impacts, and other aspects of each alternative which helps in arriving at a most viable alternative.
CHOICE: At this stage, the decision-making body decides all alternative /or a group of alternatives to implement in a participatory manner.  The decision-makers are required to communicate the reasons behind their choice by explaining the necessary trade offs and the anticipated impact of the chosen alternative or alternatives on the communities.
RISK ANALYSES: Economic and environmental consequences of each alternative are discussed in such a manner, the public understands the results of choosing one alternative over another to avoid future annoying of public.
Implementation STRATEGY: While implementing the suggested or agreed alternative, the steps necessary to carry out the program are described and potential adverse impacts are mitigated, if possible, which helps in coordinating the public and beginning of the programme successfully.

EVALUATION AND MONITORING: The managing authorities continually evaluate the model and solicit input from affected groups.  Ongoing evaluation and monitoring helps provide an information base for making future waste management decisions and understanding the system health.
 

Spatial and temporal analyses tools such as Geographic Information System (GIS) and Remote Sensing data (Satellite information) are playing a pivotal role in management of natural resources, urban planning, etc. since last two decades.
GIS play fundamental role in the application of spatial data to any environmental modeling with or with out remote sensing data.  The integration of spatial data and corresponding attribute data which refer to qualities or characteristics of places with spatial and location information (data base management systems) with the help of computers have revolutionized environmental modeling. These developments have played a prominent role in rapid and reliable analysis of spatial data.

• Use of Geoinformatics in planning the alignments of linear features like road, railways and canal etc. have become quite popular on account of many commercial GIS and CAD software available in the market.
• Organizations like Survey of India, where the Digital Cartographic Data Base (DCDB) is already available in 1:250,000 scale, are using the Digital Elevation Model (DEM) for generating road and railway alignments and alternative route plans.
• Geoinformatics and related GIS technologies are already being activated for sustainable environment planning, hazard predictions, monitoring and planning of related mitigation programmes like predicting land slides, earth quakes, cyclones, natural resource management, water quality monitoring, routing and transportation applications etc.

Geographical information system (GIS) is a systematic integration of computer hardware, software and spatial data, for capturing, storing, displaying, updating, manipulating and analyzing in order to solve complex management problems.  GIS is used as a tool, which aids in analyzing the data obtained with reference to their geographic location (Strafaci, 1999). GIS aids as decision support system with spatial maps and attribute databases.  GIS integrates maps with reports, graphs and photographs to present results into powerful tools for decision-makers.

Cartographic display system: This system allows users to select and extract a particular database or map output on the screen or printer etc.                                                         
Map digitizing system: This system enables users to convert existing paper maps to digital form, thus further aids in developing database.
Database management system: This system has the ability to analyse the attribute data. Term "attribute" refer to qualities or characteristics of places with spatial and location information. Software, which provides cartographic display, map digitizing and database query capabilities, are often referred to as automated mapping facilities management (amfm) systems (Ronald Eastman, 1997)
Geographic analysis system: This component has the ability to analyse the truly spatial characteristics.  Term "spatial" refers to any two or three-dimensional data whether or not it relates directly to the surface of the earth.
Image processing system: It helps to analyse and classify the remotely sensed images (digital images) according to various classification techniques, which could be interpreted with the help of training data.
Statistical analysis system: This helps in statistical analysis of spatial and temporal data which is required in scenario analyses.

4.3 GIS TASKS

Import data: Probably the most time intensive step in setting up a GIS is obtaining spatial and attribute data sets in a consistent format and scale.  Spatial maps used till now in paper format (by many agencies) are converted to geo-referenced digital format through scanning, digitization and geo referencing techniques. This can be updated with the latest information through satellite information. Attribute data may be entered manually or may be imported from preexisting sources. 
Database Management: GIS is essentially a spatial map linked to attribute database. It manages the underlying spatial and attribute data in a Relational Database Management System (RDBMS).  Relational databases store various layers of information in tables and are linked together by common fields.
Querying and Data Analysis: Performing queries is the most useful and powerful analytical capabilities of a GIS.
Visualisation of Data: Visualisation is one of the vital capabilities of GIS, helps to display results of query and in creation of high impact visuals, which are easy to interpret.

• VIABLE STRATEGIES: Strategic approaches for SWM is integration of available data, guidelines and framework and elimination of the constraints. Main objective of SWM is to arrive at a proper storage with least negative environmental impact, efficient collection system, engineered processing and disposal (according to constituents present in the waste stream). Analysis of spatial data i.e., landuse and land cover pattern, transport network, collection network etc., along with information related to quantity and quality of wastes  (through GIS) enable the authorities involved in the solid waste management to come out with feasible options.
• POSSIBLE SOLUTIONS: Arriving at viable strategies and wise decisions enables the authorities to handle the waste effectively and remove discomforts to public.  Utilization of available technology and expert involvement in the management could fulfill the aspirations of public and authorities.  The data available on waste generation, sources, local conditions for collection system and capacity of managing authorities help in designing a proper management system, thus eliminating problems related to storage, collection, and disposal.

STUDY AREA:  IISc (Indian Institute of Science) campus is chosen for developing a feasible SWM strategy. The campus limits are enclosed within 13.010550 to 13.020830 latitude and 77.559440 to 77.573880 longitude. The area falls in the 57G/12 of Survey of India (SOI) toposheets of scale 1:50000, 57/G of scale 1:250,000.

IISc is located in the northern part of Bangalore City having lush vegetation and campus has green canopy of trees covering the buildings.  The campus, consisting of five bounds, covers an area of 180 hectares.  The main campus covers around 150 hectares.  The elevation at IISc campus varies from 914 m to 942 m (from mean sea level).  The natural terrain of the campus is rolling and provides good natural drainage.  Eastern part of the campus forms the major portion of the catchment area of Sankey Lake located to the Southeast of the campus (Fig 1).  A large drain running all along the eastern side of the campus forms the main feeder to the Sankey Lake. Fig 2 provides the boundary of IISc with geo co-ordinates while Fig 3 maps the buildings and Fig 4 refers to road network.

This study explores the present waste handling practices within the IISc campus with various interdisciplinary activities (40 departments, 400 faculty members, 800 supporting staff, 1500 students and 450 residential quarters) representing a typical urban community.  The institute has all kinds of wastes arising from various sources like residential, commercial, educational, open area and vegetative area.

The nature of the waste generated within the campus comprises of,

• Domestic wastes (food leftovers, vegetable peels, plastic, house sweepings, clothes, ash, etc.)
• Waste arising from educational, administrative and commercial buildings (paper, plastics, glasses, etc.)
• Hazardous wastes arising from laboratories, health Centre (Radioactive chemicals, hazardous chemicals, infectious wastes, etc.)
• Waste arising from road cleansing (leafy matters, dust, construction & demolition wastes, etc.)
• Waste from vegetated area (litter, garden trimmings, tree cuttings, mowing etc.) 

Generation: Campus residents and visitors involved in academic, administrative and commercial activities produce considerable quantity of wastes.  Generation of wastes varies with season, academic and social activities and time.  During the festivals, seminars, etc the generation rate is considerably high.
The campus has 45% of vegetative cover through out the year (Murari, 1999) and litter production is quite high. Litter production varies with season and type of tree species. Quantification of litter entailed a detailed field survey along with land cover and land use analyses.

Storage: Waste bins of various types are distributed all over the campus in different locations to ensure the waste is not dumped on the roadside.  Different types of waste bins namely cylindrical concrete bins (CON), small wooden bins (SB), cubic concrete bins (CUB), masonry hut bins (HUT) and stone bins (STB) are in use.  Hut bins are constructed at key locations where quantity of waste expected is quite high.  Daily collection at hut bins constitutes about 20% of total solid waste in the campus.  Figure 5 depicts the location and distribution of bins.
Small bins are provided to collect frequently generated wastes such as cigarette covers, envelopes etc. and are placed at strategic locations.  Concrete bins, stone bins and cubic bins are provided at places, where waste is expected regularly. In spite of all these, wastes are openly dumped on the ground at various locations for varying periods of time (Fig. 5).
Collection: Campus solid waste management is handled by the Estate Office. Initially, collection was done by workers employed by estate office with the help of one tractor and a pick-up mini-truck.  Total crew size is six members and two drivers (to operate in two shifts).  Four loads of waste were taken and the daily crew operated in two shifts (morning two and afternoon two).  Recently (November 2000) the collection was entrusted to Bangalore Development Authority (BDA) recognized waste collection agents.  Two truckloads are taken out daily and the crew size is 8 workers and 2 drivers.  The frequency of collection from each bin is now 1 to 3 days (i.e., all bins are cleared once in 1 to 3 days).  Collected wastes are dumped and burnt at common dumping site about 12 kms away from IISc. With this approach, while the institute environment is kept reasonably clean but valuable resource (70% of which is fermentable organic waste) with a significant plant nutrient load is being lost.  This could have been converted to wealth through appropriate technologies available at campus.
Mostly community bin collection mechanism has been employed.  The domestic waste is collected with all other wastes arising from other activities, which increases weight of waste to be transferred.  In some localities such as duplex, E-Type, D-Type and Tunga residential staff quarters (Fig 3), door to door collection has been attempted recently.  Collection charge per household per month is Rs.15. Regular street sweeping and roadside garden trimmings are done and wastes are dumped in bins and sometimes in drainage also.
Transferring: Transferring the waste from dustbins to vehicles is done manually with the use of spades, rakes and similar equipment and transferred to the collection vehicle.  Inadequate precautions are taken while handling harmful wastes such as glass, biological wastes etc.  The route followed currently is the one convenient to driver rather than from the collection point of view or from type and composition of wastes.  All sensitive bins are not given priority in this method of collection.  There is a need to evolve an optimal route evolved on the basis of waste composition and quantities generated in each bin.  Till November 2000, collected waste was transferred to dump yard (located in North-eastern side the campus).  These dumped piles were frequently burnt. Today, by entrusting the responsibility to BDA recognised contractors, waste is transferred to BDA's dumping yard near Madivala, Bangalore.  Wastes dumped in dump yard were frequently burnt which caused both health hazards from toxic fumes and organic resource loss. This necessitates the wise use of organic wastes and environment-friendly disposal options.  Damage to the ecosystem and the immediate environment has to be accorded the highest priority in deciding this options.
Disposal: Both in the past and in the present, inadequate attention has been paid to engineered disposal and its practice.  Waste is simply dumped on the ground, open to the atmosphere as followed elsewhere without appropriate treatment and resource recovery practice.
Waste picking: Waste is accessible to waste pickers, who segregate re-saleable matter (paper, plastics, glasses, metal pieces etc.).  Rag pickers segregate the wastes directly from the dustbins without any protective gloves and are exposed directly to harmful wastes. Due to this informal segregation, some volume reduction is achieved. However, such segregation disturbs the aesthetics of the collection system as wastes are littered all around the place.
Food wastes (food leftovers, vegetable peels, etc.) from various messes, used as animal feed are collected by agents regularly. Fresh surplus food is transferred to schools.
Source segregation: An attempt was made to segregate paper and plastics in the academic area by providing separate bins in all rooms in selected departments [Centre for Electronic Design and Technology (CEDT) and Centre for Ecological Sciences (CES)] for inmates to dispose plastic and paper in separate dustbins.  From small dustbins in each room, wastes are then transferred to big containers located at common place, so that the contractor appointed by the institute can collect the waste.  Segregation at individual level has been working reasonably well while at next stage (transferring to big container and then collection by a contractor), the practice has come to an end, due to lack of monitored collecting mechanism at IISc.
Hazardous wastes: Wastes that cause potential hazards to humanbeings and animals are referred to as hazardous wastes.  Generally hazardous wastes can be classified into three categories namely, radioactive wastes, biological wastes and hazardous chemicals.  At IISc, radioactive chemicals are used by various departments generally as radiotracers.  Radioactive substances like Tritium, Phosphorus (32P), Sulphur (35S), carbon (14C), Iodine (125I), etc are used.  The Institute has designed an innovative method to dispose radioactive wastes in an environmentally sound way in concrete silos with least or no harmful effect on eco-system.  On the last Thursday of every month, wastes collected from individual departments are put into appropriately labeled containers and sealed and placed at radioactive waste disposal site.  These are ensiled according to conventional practices of handling low-level radioactive wastes.
Very few departments at IISc use hazardous chemicals.  Hazardous chemicals such as solvents, carcinogenic chemicals, etc  are used in about five departments. Used chemicals from various laboratories are given varying levels of importance with respect to disposal practices and they are often mixed with general liquid wastes. Hazardous chemicals such as solvents, carcinogenic chemicals, etc. rejected from various laboratories are given inadequate importance and they are often mixed with general liquid wastes.  A few workplaces however use fume hoods to dispose of mildly carcinogenic solvents.  Acids and alkalis are typically dispersed by dilution with water.  Mutagenic substances used are few and used in very small quantities. However, sometimes they are disposed along with bottles, packing material and mixed with general solid waste stream.
Pathogenic hospital wastes (1-4kg/week) (COMIND-SWM, 1999) and animal bedding material are disposed by a common incinerator.
Litter: Litter is usually the dried parts of plants fallen on the ground. The litter largely contains leaves, flowers, fruits, seeds and twigs. Litter can be a non-timber plant products (NTPP) too - an economically important waste and could be converted to wealth with proper management (currently collected litter is transported out of campus and is burnt, thus the valuable wealth is lost).  This resource if managed properly would return valuable nutrient to the soil.  However, burning bioresource in dump yard leads to air pollution and affects surrounding inhabitants.
The IISc campus is covered with good vegetation canopy throughout the year.  The litter produced and litter collected by collection vehicle is about one truckload /day containing dry and green leaf litter.  The case study explores the following important issues,