TABLE OF CONTENTS
List of Symbols and Abbreviations
1.2 Problems and Constraints in Solid Waste Management
1.3 Scenario of Solid Waste Management in India
1.4 Solid Waste Management in Pondicherry
1.5 Geographic Information System
1.6 Need of the Study
1.8 Study Area
2 Review of Literature
2.2 Solid Waste Management
2.3 Impacts of Solid Waste Disposal
2.4 Solid Waste Disposal Options
2.5 Site Selection for Solid Waste Disposal
2.6 Applications of Geographical Information System
3.2 Steps Adopted in the Present Study
3.3 Assessment of Environmental Problems at the Dumpsites
3.4 Selection of Sanitary Landfill Site
3.5 Preliminary Design for Sanitary Landfill
3.6 Proposed Routing for Waste Transportation
3.7 Evaluation of Solid Waste Management Options
4 Results and Discussion
4.2 Assessment of Environmental Problems at the Dumpsites
4.3 Selection of Sanitary Landfill Site
4.4 Assessment of Environmental Suitability of the Proposed Landfill Site
4. Preliminary Sanitary Landfill Design
4.6 Proposed Route for Solid Waste Transportation
4.7 Suggestions for Best Management Practices in Pondicherry
5 Summary and Conclusions
LIST OF SYMBOLS AND ABBREVIATIONS
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Waste is an unavoidable by product of human activities. Economic development, urbanization and improving living standards in cities, have led to increase in the quantity and complexity of generated waste. The solid waste generated in Pondicherry contains a fairly high percentage of organic matter and poses low calorific value. Solid waste is mainly disposed off by open dumping in the low lying areas in and around the city. Open dumping of solid waste along roads, river banks, low lying areas in the outskirts of the cities etc., poses environmental pollution. To minimize the problems related with waste disposal, there is a need to identify suitable landfill site for proper disposal of solid waste as well as the available technologies of waste disposal should be evaluated. It is equally important to identify transportation route based on the environmental considerations for disposal of solid waste from transit stations to landfill site to optimize vehicle routing system.
The study area, Pondicherry having 293 sq.km area located between latitudes 11° 46’ N and 12° 03’ N and longitudes 79° 36’E and 79° 53’ E is the first largest among the other regions of Union Territory of Pondicherry. Solid waste was dumped in open dumping grounds at Dubrayapet and Mettupalayam in Pondicherry. The disposal of solid waste is now being done in the low lying areas in a haphazard manner and at Karuvadikuppam dumping ground.
In the present study, the environmental problems of the existed dumpsites were assessed by analyzing the quality of groundwater and ambient air during three seasons viz., pre monsoon, monsoon and post monsoon. Leachate quality of the existed dumpsites, physical and chemical characteristics of solid waste generated at present were also studied. Considering various criteria specified by CPHEEO and CPCB, suitable landfill site was identified for the solid waste disposal of Pondicherry using GIS. From the pre and post monsoon monitoring of groundwater, surface water and ambient air quality within 5km radius and by analyzing the soil characteristics, the environmental suitability of the proposed landfill site was assessed. Preliminary design for the proposed landfill site was worked out. Transit stations were identified in Pondicherry and Oulgaret municipalities. Proposed route for transportation of solid waste from the transit stations to the proposed landfill site was also suggested. Number of vehicles required for transportation and their time schedule were determined. Suitable solid waste management options for Pondicherry were evaluated.
Higher concentrations of heavy metals viz., Fe, Cr, Cu and Zn, total hardness, sulphate, chloride and coliform count are observed in the leachate. Some groundwater parameters are in higher concentration around the dumpsites. Deterioration of groundwater quality observed around Mettuppalayam is not only due to the indiscriminate dumping of solid waste, also due to industrial activities. Air quality is within the prescribed limit. Characterization of present waste generated indicates higher percentage of organic content and low calorific value.
Out of 17 sites identified for solid waste disposal, based on sufficient area, higher depth of bed rock, fracture free zone, gentle slope, groundwater level and low infiltration, only 3 sites are suitable for landfill. The trench method of landfill is ideally suited to the proposed sites where the groundwater table is low. As per the landfill design, the area required for the disposal of waste generated in Pondicherry is only 0.21sq.km. Assessment of the environmental suitability of the proposed landfill site indicates that high concentrations of TDS, magnesium and iron in groundwater may be due to soil chemical parameters. Surface water quality and ambient air quality parameters reveal that all the parameters are within the prescribed limit. From the soil profile of the proposed landfill, it is observed that the percentage of clay is higher which can be considered as a natural liner in the prevention of leachate contamination into the groundwater.
For the suggested routing, 26 transit stations are identified. For transportation of solid waste from transit stations to landfill 19 Nos. of heavy load carrier vehicles are proposed. Transportation of waste is scheduled during 6.00a.m and 7.30a.m; 9.30a.m and 1.00p.m; 2.00p.m and 4.00p.m.when there is less traffic volume. Methane emission from the proposed sanitary landfill can be estimated as 2668 tons/yr, which can be used as an energy source in the nearby village either as a direct use of the gas or in the generation of electricity and distribution through the power grid.
In the developing countries, the ever-increasing human population and the associated anthropogenic activities have accelerated the phenomenon of urbanization in the past decade. In India, the rate of increase of urban population shot from 11% in 1901 to about 26% in 2001. The census of 2001 indicates the fact that presently 25.73% of the total population resides in the urban centers, which has been forecasted to rise to 33% in the next 15 years (PPCC, 2005). The rapid growth rates of the cities, combined with their huge population base, has left many Indian cities lacking in basic infrastructural services like water supply, sanitation and sewerage and solid waste management. With the rising population and the associated unsustainable practices, there has been an enormous increase in the quantum as well as the diversity of the solid waste being generated.
In India, solid waste is assuming larger dimensions due to continuously increasing population and areas of urban centers. It is estimated that about 100000 MT of municipal solid waste (MSW) is generated every day in the country. Urban Local Bodies spend about Rs.500 to Rs.1500 per ton on solid waste for collection, transportation, treatment and disposal, in which, about 60-70% is spent on collection, 20 to 30% on transportation and less than 5% on final disposal ( CPHEEO, 2000 a). The problem of solid waste has assumed significant dimension especially in the urban centers. Domestic, Industrial and other wastes, whether these are of low or medium level have become a perennial problem as they continue to cause environmental pollution and degradation. Poor waste management systems coupled with hot climatic condition results in increasing environmental problems with significant local as well as global dimensions. The need of the hour is to devise an efficient solid waste management system wherein the decision-makers and waste management planners can deal with the increase in complexity, uncertainty, multi-objectivity, and subjectivity associated with this problem.
In spite of the increasing stress towards the waste reduction at source as well as recovery and recycling of the solid waste, disposal of solid waste through landfills remain the most commonly employed method. Landfill incorporates an engineered method of disposal of solid waste on land in a manner that minimizes environmental hazards by spreading the solid waste in thin layers, compacting the solid waste to the smallest practical volume and applying a cover at the end of the operating day. However, with the increased population density and urban infrastructure, several key considerations are required to be taken in to account to ensure its overall sustainability, especially those associated with its economics, optimized siting and operation.
In order to avoid the degradation of environmental quality due to open dumping and to minimize short- and long-term problems related with waste disposal, there is a need to identify suitable landfill site for proper disposal of solid waste. Sanitary land filling involves various stages such as selection of site, planning for land filling operation, construction of the site as per plan, closure of the site and environmental monitoring. Site selection is the most important one as it forms the basis for the remaining stages.
1.2 PROBLEMS AND CONSTRAINTS IN SOLID WASTE MANAGEMENT
A typical solid waste management system in a developing country displays an array of problems, including low collection coverage and irregular collection services, crude open dumping and burning without air and water pollution control, the breeding of flies and vermin, handling and control of informal waste picking or scavenging activities. The success of waste disposal practices depends largely on overcoming the following constraints
1.2.1 Technical Constraints
- Lack of overall plans for solid waste management. As a result, a solid waste technology is often selected without due consideration to its appropriateness in the overall solid waste management system.
- The coverage of solid waste collection service is so low that solid waste generated is dumped at many undesignated sites such as open areas, water channels, streets etc. As a result, improving the disposal site would have little impact on the overall solid waste management effectiveness. In such a case, the low collection coverage is a bottleneck in the overall solid waste management system in the city, and it would be most cost-effective to provide resources to upgrade the collection service.
- Research and development activities in solid waste management are often a low priority in developing countries. This leads to the selection of inappropriate technology in terms of the local climatic and physical conditions, financial and human resource capabilities, and social or cultural acceptability. As a result, the technology selected can never be used, wasting the resources spent and making the project unsustainable.
- 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
1.2.2 Financial and Economic Constraints
- In general, solid waste management is given a very low priority in developing countries. As a result, very limited funds are provided to the solid waste management sector by the governments, and the levels of services required for protection of public health and the environment are not attained.
- The problem is acute at the local government level where the local taxation system is inadequately developed and therefore the financial basis for public services, including solid waste management, is weak. This weak financial basis of local governments can be supplemented by the collection of user service charges. However, users' ability to pay for the services is very limited in poorer developing countries
- Developing countries have weak economic bases and hence insufficient funds for sustainable development of solid waste management systems.
1.2.3 Political Constraints
- 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.
1.2.4 Social Constraints
- The social status of solid waste management workers is generally low in both developed and developing countries, but more so in developing countries then developed countries. This owes much to a negative perception of people regarding the work which involves the handling of waste or unwanted material. Such people's perception leads to the disrespect for the work and in turn produces low working ethics of laborers and poor quality of their work.
- At dump sites, transfer stations and street refuse bins, waste picking or scavenging activities are common scenes in developing countries. People involved have not received school education and vocational training to obtain knowledge and skills required for other jobs. They are also affected by limited employment opportunity available in the formal sector.
- The existence of waste pickers/scavengers creates often an obstacle to the operation of solid waste collection and disposal services. However, if organized properly, their activities can be effectively incorporated into a waste recycling system. Such an opportunistic approach is required for sustainable development of solid waste management programmes in developing countries.
1.2.5 Environmental Constraints
- There are potential risks to environment from improper handling of solid waste. The most obvious environmental damage caused by municipal solid waste is aesthetic, the ugliness of street litter and degradation of the urban environment and beauty of the city. More serious, however and often unrecognized is the transfer of pollution to groundwater. Air pollution can be caused from the burning of waste either in open air or in plants that lack effective treatment facilities from the gaseous emissions.
1.3 SCENARIO OF SOLID WASTE MANAGEMENT IN INDIA
The waste generated in India under average condition is varying from 450 to 650 gm per capita per day compared to western countries of about 1300 to 1800 gm per capita per day. Though Mumbai generates the highest quantity of solid waste per day, Chennai becomes the highest in the per capita waste generated per day (Table 1.1). The per capita waste quantity tends to increase with the passage of time due to various factors like increased commercial activities, standard of living etc. All over the world today, the cities are vexed with the problem of disposal of solid waste generated. Status of municipal solid waste disposal in India is 80-100% dumping, 0-20% composting and others 1%. The city refuse generated in India contains a fairly high percentage of organic matter, as high as 60-70% dry weight. The total waste generation in urban areas in the country is estimated to be around 38 million tons per annum (CPHEEO, 2000 b).
Table 1.1 Quantity of Waste Generated in Various Cities
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Source: CPCB (2001)
Solid waste varies in quality, quantity and depends upon several factors like living habits, cultural tradition, socio-economic and climatic conditions from place to place and time to time. The characterization of solid waste is very important for its disposal considerations. Composting is recommended for waste rich in organic matter and landfill is the most appropriate for inert fraction. Similarly contents of heat (calorific value) of solid waste decide its suitability for incineration.
Landfills have been used for many years as the most common method for the disposal of solid waste generated by different communities (Komilis et al., 1999). Even with the implementation of waste reduction, recycling and transformation technologies, disposal of residual solid waste in landfills still remains an important component of an integrated solid waste management (SWM) strategy.
Landfill is the ultimate disposal of solid waste though its management is largely unscientific and unsatisfactory. Solid waste in urban areas not only pollute surface water and air but also pollute groundwater, when improperly managed (Hanks, 1967). Urban solid waste contain food discards, foliage (garden), paper, plastic, rubber, leather etc., Therefore landfill matter contains a vide spectrum of bacteria, actinomycetes and fungi (Cook, 1967).
Landfills can also turn into a resource. Methane gas is recovered from many landfills today. After closure, landfills can be used for recreation areas. Some agencies and entrepreneurs are looking at landfills as repositories of resources for the future. The urban areas of Asia produce approximately 8 million tons of municipal solid waste per day (World Bank, 1999). Open dumping is the most common solid waste disposal method in the region. The state of the dumping are sadly too similar: indiscriminately dumped, seemingly unplanned heaps of uncovered waste, sometimes burning, pools of standing polluted water, insects and rodent infestations and families of waste scavenger picking up any valuables from waste (Pugh,1999). Indiscriminate landfilling leads to deterioration of water quality in neighborhood areas of landfill sites due to contamination by leachate from the landfills. This has adverse health impacts on people living nearby, causes bad odours, and the people living nearby live in the constant fear of explosion of methane gas that can accumulate at the landfill sites.
1.4 SOLID WASTE MANAGEMENT IN PONDICHERRY
1.4.1 Collection and Disposal Practices by Municipalities
Solid waste generation sources in Pondicherry are residential, markets, bus stand, hotels, restaurants, marriage halls, Government offices, parks, cattle waste and hospitals. The total quantity of waste generated in Pondicherry works out to 300 tons/day. Average per capita solid waste generation in Pondicherry town is around 450gm/day. From Figure 1.1, the projected rate of waste generation by 2026 as per the population growth would be 0.198 million tons (CPHEEO, 2000 c).
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Figure 1.1 Projected Rate of Waste Generation
The solid waste is being managed by Local Administration Department through municipalities. At present, the solid waste is being disposed of at Karuvadikuppam. No organized method of waste disposal is being practiced at the site. The solid waste collection vehicles generally tip off the waste at convenient locations anywhere in Pondicherry. Monitoring of collection vehicles at the disposal site is not in practice. The primary collection mechanism is devoid of a systematic planning. Inventory of major and minor streets is not maintained. The work schedule, allotment of streets to particular conservancy labour is being done on an adhoc basis rather than need basis. In such scenario, few streets get more attention and few others are totally neglected. Similarly, there is a gross inadequacy in placing dustbins. This leads to indiscriminate dumping of solid waste in the streets and lanes of the towns. This emphasizes the need to reorganize the primary collection system at Pondicherry.
Secondary collection mechanism is a critical link from waste generation sources to disposal sites. Except Pondicherry town limit, all the other areas do not have any secondary collection arrangements. In order to ensure a minimum of 90% collection efficiency, the secondary collection arrangements should be planned in such a manner that the waste collected from the households are disposed at the designated transfer stations from where the vehicles can collect and dispose the waste to the landfill site. At present, no formal segregation of recyclable waste is practiced either at the residence or at the commercial spots. But, once the waste is put in the bins kept on the streets or if the waste is simply dumped on the streets, the rag pickers collect the recyclable waste by dismantling the entire contents of the bins. Though rag picking supports the recycling industries, it makes the waste storage area uglier and the rag pickers are exposed to various health hazards.
1.4.2 Composting by PASIC
Pondicherry Agro Services and Industries Corporation Ltd., ( PASIC) has compost yard, at Arasur and Krishi Vigyan Kendra (KVK), Kurumbapet to handle waste everyday around 100 tons and 75 tons respectively (INTACH, 2005). Pondicherry and Oulgaret municipalities supply waste to Arasur compost yard and KVK respectively. The collected waste is made into windrows of size 30 – 40m length, 3m width and 1m height (Figure 1.2). The windrows are inoculated with cow dung slurry. Six turnings are done at weekly intervals. Composting gets over by 45 days. After composting, non-biodegradable waste are removed from the compost with the help of a trommel and landfilled in the yard itself. About 20 percent of compost could be recovered from the waste which is sold at the rate of Rs. 800 per ton.
The compost is enriched by adding Azospirillum, Phosphobacterium, Pseudomonas, Coir pith waste, Zinc sulphate (ZnSO4) and Magnesium sulphate (MgSO4). The cost of enriched compost is Rs. 1520 per ton. The compost thus obtained is sold to the farmers with 75% subsidy through the Department of Agriculture in Pondicherry and also sold in small bags through local markets and to the nearby villages in Tamilnadu.
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Figure 1.2 PASIC Compost Yard
1.4.3 Composting by Green Diamond
Under the Asia Urbs programme, Pondicherry municipality supplies about 5 tons of organic waste from the vegetable market to the Green Diamond vermi composting yard at Dubrayapet (Figure 1.3), lying near the new light house. A portion of the rehabilitated area previously a dumpsite for municipal waste was allocated for developing the infrastructure for a vermi compost yard. A self-help group consisting of women from underprivileged families selected by Pondicherry municipality were trained on the vermi composting process at a specialized facility in Tanjore are involved in the activity. Initially slurry of cow dung as inocula is added to the waste and placed them in heaps for composting. The compost heaps are turned once in 15 days for 3 times. The pre-composted waste is subjected to vermi-conversion. The earthworms eat up the decomposed waste to leave behind vermi casts, which are harvested once in 5 days, sieved and packed. About 90 percent of vermi compost could be recovered from the pre-composted waste (about 20% of the total waste). The compost thus obtained is sold through local markets.
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Figure 1.3 Vermi Composting Yard at Dubrayapet
1.5 GEOGRAPHIC INFORMATION SYSTEM
It has been commonly known that most of the service sector organizations in our country operate at low productivity levels for which one of the major limitation being lack of availability of appropriate key information at required time, in the absence of which decision making is either delayed or results into low productivity.
GIS is a digital database system designed to manage large volumes of spatially distributed data from a variety of sources. GIS makes it possible to link or integrate information that is difficult to associate through any other means. GIS can recognize and analyze the spatial relationships among mapped phenomena. It is ideal for site selection studies because it efficiently stores, retrieves, analyses and displays information according to user-defined specifications. Thus once a GIS database is developed it can provide an efficient and cost effective means of analyzing potential landfill site. However, GIS can be limited by the accuracy of the data. Further, the resulting site analysis is sensitive to the importance given to the individual themes (Muhammad, 1996).
In the early stages of development of GIS, for overlay analysis various theme maps were copied on transparencies with common bounding lines and kept over one another to find out specific areas satisfying certain conditions. These were possible when the quantum of data was small. Today, with the availability of large volume of data sets from different sources, manual operation is no longer possible. The presence of high-speed computers with large space for manipulation and storage enable to switch over from manual GIS to computer based GIS system (Carter, 1996). GIS network analyst determines optimal route for the transportation of solid waste. A route is defined by specifying the origin, points through which it will pass, stops at the expected destination. The impacts of different routes can be determined.
1.6 NEED OF THE STUDY
The exponential rise in the urban population in the past few decades and the resulting accelerated urbanization phenomenon has brought to the fore the necessity to develop an environmentally sustainable and efficient waste management systems. Sanitary landfill constitutes one of the primary forms of municipal solid waste disposal systems. Optimized siting decisions have gained considerable importance in order to ensure minimum damage to the various environmental sub components, as well as reduce the stigma associated with the residents living in its vicinity, thereby enhancing the overall sustainability associated with the life cycle of a landfill.
The solid waste generated in Pondicherry is mainly disposed off by open dumping in the low-lying areas in and around the city. They become a source for objectionable smoke and odour, and serve as breeding grounds for flies and mosquitoes. Open dumping of solid waste along roads, river banks, low lying areas in the outskirts of the cities etc., poses pollution threat in all the three media of environment i.e. air, water and land, and affects the living beings. Care should be taken to prevent run off from the disposal of solid waste in the upstream and contamination of groundwater and surface water. Necessary measures shall be taken to prevent leachate contaminating the soil.
To minimize the problems related with waste disposal, there is a need to identify suitable landfill site for proper disposal of solid waste. The proper disposal of municipal solid waste is not only absolutely necessary for the preservation and improvement of public health but it has an immense potential for resource recovery.
Improper management of MSW is causing severe environmental concern which could otherwise safe guard the depleting natural energy resource. It is not practicable to collect methane from the existing waste dumps and hence it escapes to the atmosphere. Hot climatic conditions further this problem with faster methane generation rates. Therefore, a sanitary landfill system should be developed which can take the advantage of these favouring conditions in handling methane emissions and the ever rising waste management problem. It is equally important to identify transportation route based on the environmental considerations for disposal of solid waste from transit stations to landfill site to optimize vehicle routing system. To evaluate available technologies of waste disposal, it is necessary to study base line environmental conditions of the dumpsites, characteristics and composition of solid waste.
In the recent years, there has been consensus amongst the decision makers and town planners towards the evolution of mechanisms to reorganize the primary and secondary waste collection system at Pondicherry as well as to the establishment of a centralized landfill at an appropriate location to cater to the needs of the entire region. The present study focuses upon an optimized site selection based on geographic information system based (GIS) overlay analysis. The most appropriate landfill site had been identified for Pondicherry, a typical urbanizing city of India. Several important factors and criterion were considered to arrive at the optimum siting decision including the pre-existing land use, location of sensitive sites, infiltration, water bodies, water supply sources, fault line and geology. Thematic maps of the selected criteria were overlayed with the appropriate weightages within the paradigm of standard geographic information system software.
The objectives of the present work are as follows:
- To assess the environmental problems due to the earlier dumpsites and present solid waste management practice.
- To identify a suitable landfill site using Geographical Information System (GIS) and assess its environmental suitability.
- To propose solid waste collection strategy – route between transit stations and proposed landfill site, vehicle requirement and their time schedule.
- To suggest the best option for the solid waste management of Pondicherry.
1.8 STUDY AREA
The Union Territory of Pondicherry comprises of four interspersed geographical entities namely Pondicherry, Karaikal, Mahe and Yanam having total area of 492 sq.km. Pondicherry is the first largest among the other regions having 293 sq.km area located between latitudes 11° 46’ N and 12° 03’ N and longitudes 79° 36’ E and 79° 53’ E (Figure 1.4). The region is also not a contiguous one, but it is interspersed within the areas of Tamil Nadu. Three major physiographic units observed in the region viz. coastal plain, alluvial plain and the elevated lands are on the north and northwest part of Pondicherry region. As per 2001 census, the population of Pondicherry region is 7,35,004 (PPCC, 2005). Pondicherry comprises of two municipalities - Pondicherry and Oulgaret, and five commune panchayats viz., Ariankuppam, Bahour, Nettapakkam, Mannadipet and Villianur. The major portion of the region is a flat, monotonous plain with an average elevation of about 15m above mean sea level. Few portions of the land is little undulatory with high grounds varying from 30 to 45m above mean sea level.
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Figure 1.4 Study Area
Pondicherry experiences hot and tropical climate. Pre monsoon (southwest) lasts from July to September, October and November constitute the monsoon (Northeast), winter season covers December to February followed by summer season from March to June. There is no real cool weather season, but the period from December to February is relatively cool.
The monthly humidity averages of the region are presented in Table 1.2. The mean daily temperature of the region during monsoon and winter periods ranges from about 25°C to 32°C and during hottest period of the year the mean daily maximum and minimum temperature is at about 37°C and 27°C respectively (LAD,2000). On individual days, the maximum temperature may even reach 43°C. The relative humidity of the region is generally high. It ranges around 70% from August to April and 60% between June and July.
Table 1.2 Decadal Trend of Climate Parameters of Pondicherry
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Source: Regional Meteorological Centre, Chennai
The average annual rainfall in Pondicherry region is around 1400mm with around 60 rainy days a year (Table 1.3). North east monsoon during October and November contributes more than 50% of the total rainfall of Pondicherry. The maximum rainfall recorded was in 1996 which was as much as 2160mm as against the average of 1400mm. Similarly, the lowest rainfall was recorded in 1995 with a low of 922mm. An analysis of historical data presents that drought conditions prevail in the region where the annual rainfall is less than 75% of the normal and may be expected to prevail over the region once in four years on an average (LAD, 2000).
Table 1.3 Rainfall Pattern of Pondicherry
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Source: Indian Meteorological Department, Chennai.
Wind in Pondicherry region is moderately strong throughout the year, except during the transition months of February-March before the summer season and during October before the onset of the north east monsoon. During May to September, winds are mainly south westerly in the mornings and south easterly in the afternoons. In October, winds take a northerly component due to the development of the seasonal low over the South Bay of Bengal and in November the northeasterly winds are fully established which remain till January. From February, a westerly component begins to predominate in the mornings, while in the afternoon, winds tend to revert to i.e. south easterly in direction. The season wise wind movement pattern is presented in Figure 1.5.
Figure 1.5 Seasonal Wind Pattern
Source: Indian Meteorological Department, Chennai
The region is drained by two rivers viz. Sankaraparani and Penniar. These two rivers with their tributaries run through the Pondicherry region and drain into the Bay of Bengal. Sankaraparani river crosses the region diagonally from northwest to southeast. This river is also known as Gingee or Varahanadhi. The river has its source at the hills of Malayanur in the South Arcot District of Tamil Nadu. The river splits into two branches namely Ariankuppam river in the north and Chunnambar in the south. Penniar river originates from the hills of Karnataka and enters Pondicherry region after flowing through Dharmapuri, Salem, North Arcot and South Arcot Districts of Tamil Nadu State. This river traverses near the southern border of the region. There are about 90 tanks in the Pondicherry region prominent among them being the Ousteri and Bahour tanks which constitute the main depression storage in the area.
In spite of limited land in the Pondicherry region, it provides exhibition of soils ranging from sandy soil to heavy clay soil, red soil to black soil, calcareous soil, non-calcareous soil etc. However, alluvial soil is the dominant in the region.
The entire area of Pondicherry region is covered by sedimentary formations, ranging in age from cretaceous to recent, except a small extent of area in the northeastern part of Pondicherry. The oldest sedimentary formations are the cretaceous sediments of Mesozoic era and are exposed in the north western part of the region and north of Gingee river. The trend of these formations is northeast-southwest. Four stratigraphic units namely Ramanathapuram, Vanur sandstone, Ottai claystone and Thuruvai limestone formations have been identified.
The Paleocene formations of the Lower Tertiary are represented by the Kadaperikkuppam and Manaveli formations in the region. The trend of these formations is similar to the cretaceous formations. The Kadeperikuppam formations are exposed near Pillaiyarkuppam, Sedarapet, Kadaperikuppam and Alankuppam. The thickness of this formation varies widely which may be due to the unevenness of the cretaceous basement. The thickness of the formation varies from 30 m to 130 m at outcrop area and maximum thickness of 450 m is observed at Manapet along the coast in the southeastern side.
The recent (Quarternary) formation in the region is represented by laterites and alluvium laterites occur as thin cap over the Cuddalore formation. Thick alluvial deposits are built up along the course of Penniar and Gingee rivers covering three fourths of Pondicherry region. The thickness of alluvium varies from 10m to 55m at different places with a maximum of 55 m at Sathyamanagalam.
The sedimentary formations (LAD, 2000) occurring in the entire region are represented by Cretaceous, Paleocene, Mio-pliocene and Quarternary formations (multilayered aquifer system). Groundwater occurs in these formations both under water table as well as confined conditions and is being developed by dug wells, dug-cum-bore wells and tube wells.
Among the various water bearing formations of cretaceous age the Ramanathapuram and Vanur formations are potential aquifers. They occur in the northwestern part of Pondicherry region. The thickness of the aquifer ranges between 38m and 98m. Groundwater occurs under confined conditions and the piezometric head is about 20 m to 33 m below ground level. The yields of the tube wells tapping these aquifers range between 500 and 1500 litres per minute. The transmissivity values of these aquifers range between 92 to 1925 m2 per day and the storage coefficient varies from 2.93 ´10-5 to 1.36´ 10-4.
The Cuddalore sandstone aquifer (the upper tertiary) occupies an extensive area (65%) in this region. The aquifer attains great thickness in Bahour, Ariyankuppam and Pondicherry municipalities. Also in some parts of Oulgaret, Nettapakkam, Villianur communes and south of Gingee river the aquifer has greater thickness. The thickness of the aquifer ranges from 20m at Oulgaret municipality and 245m at Manapet in Bahour commune. Groundwater occurs in the aquifer mainly under confined conditions and yield is ranging from 200 to 3000 litres per minute. The average transmissivity is estimated as 2000m2/day and the storage coefficient values range between 9.583 х 10-5 and 8.9 х 10-4. The piezometric level in the aquifer ranges between 6m and 25m below ground level.
Alluvial (recent formations) deposits occupy nearly three fourth of Pondicherry region. This is the most potential shallow aquifer system in the region. The thickness of this aquifer ranges between 5m and 34m. Groundwater occurs under water table or under semi-confined conditions. The transmissivity values of the aquifer in the west (Madukarai) are 275.4 m2 per day and 770 m2 per day in the east (Thirukanjee). The water level in the aquifer ranges from 12m to 15m below ground level.
1.8.7 Solid Waste Dumping Grounds
In Pondicherry, solid waste was dumped in open dumping grounds at Dubrayapet and Mettupalayam. Dubrayapet dump site is spread over an area of 0.1 sq.km and located close to the sea and situated in the eastern corner of the Pondicherry town. It is 5km away from the city centre and it is around 400m away from the coastline. There are no settlements within 500m distance of the site except few slum dwellers on the seacoast. However, larger group of hutments are found near the light house area. Whereas Mettupalayam dump site is around 0.02 sq.km and is 6km away from the city centre. It is located very close to the Industrial Estate and situated in the western corner of Pondicherry town.
Later, the solid waste is disposed at Karuvadikuppam and Kalmedupet. As the public are against in dumping the waste in Mettupalayam, Dubrayapet and Kalmedupet these dump sites were abandoned. The disposal of solid waste is now being done in the low-lying areas in a haphazard manner and at Karuvadikuppam dumping ground. Ward wise waste generation (INTACH, 2005) in the Pondicherry and Oulgaret Municipalities are given in Table 1.4. The period in which the dumps functioned are
1992 - 2001 Dubrayapet and Mettupalayam
2001 - 2003 Karuvadikuppam
2003 - July 2004 Karuvadikuppam and Kalmedupet
July 2004 - till date Karuvadikuppam and low-lying areas
Table 1.4 Waste Generation in Pondicherry
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Source: INTACH, 2005
REVIEW OF LITERATURE
In India, the collection, transportation and disposal of MSW are unscientific and chaotic. Uncontrolled dumping of waste on outskirts of towns and cities are not only impossible to reclaim because of the haphazard manner of dumping, also have serious environmental implications in terms of groundwater pollution and contribution to global warming. Burning of waste leads to air pollution in terms of increased particulate matter emissions. In the absence of waste segregation practices, recycling has remained to be an informal sector working on outdated technology, but nevertheless thriving owing to waste material availability and market demand of cheaper recycled products. Paper and plastic recycling have been especially growing due to continuously increasing consumption levels of both the commodities. Solid waste management is an integral part of the urban environment and planning of the urban infrastructure to ensure a safe and healthy environment while considering the promotion of sustainable economic growth. Rapid economic growth by industrialization of the developing countries in Asia has created serious problems of waste disposal due to uncontrolled and unmonitored urbanization (ISWA, 2002)
2.2 SOLID WASTE MANAGEMENT
Enlightened solid waste management with emphasis on controlled tipping, now known as sanitary landfilling, began in the early 1940’s in the United States and a decade earlier in the United Kingdom (Tchobanoglous et al., 1981). Solid waste management is an integration of urban and environmental management. Solid waste management includes the activities related to the generation of solid waste, its storage, collection, transportation, processing and disposal in an economic and environmentally acceptable manner. SWM encompasses planning, organization, administration, financial, legal and engineering aspects involving inter disciplinary relationships. In the developing countries, these activities fall short of the desired level, as the systems were outdated and inefficient (Nath, 1984; Bhide and Sundaresan, 1987). Rotich et al., (2005) provides an overview of the state of Municipal Solid Waste Management (MSWM) by local authorities in Kenya as a case study of a low-income developing country. Approaches of possible solutions that can be undertaken to improve Municipal Solid Waste (MSW) services are discussed. Involvement of stakeholders to achieve any meaningful and sustainable MSWM and the role of the informal sector through Community Based Organizations (CBOs), Non-Governmental Organizations (NGOs) and the private sector in offering solutions towards improvement of MSWM also is explored.
Boyle (2000) identified that the New Zealand waste management and pollution prevention programme was found to be vague, lacking in direction and funding and would not succeed in reducing waste production or effectively managing waste. Clear goals and timeframes need to be established, duties and responsibilities of national and local governments and industry need to be clarified and funding needs to be allocated in order to produce an effective waste management framework in New Zealand. Veasna Kum et al., (2004) had attempted to identify shortcomings to improve the existing system in Phnom Penh city and proposed that the issues should be addressed from a system perspective by taking into account the technological, financial, institutional, legal and socio-cultural factors to determine appropriate policies for the local surroundings. Rajabapaiah (1995) proposed free cooking gas production from Indian Institute of Science (IISc) garbage, estimated to have fermentable matter 1080kg (88%), combustible matter 60kg (5%) brickbat 50 kg (5%) and recyclable matter 26 kg (2%). This quantification was based on the data compiled at disposal site. Suggestions include ASTRA's biomass plug-flow fermentor technology for the effective utilization of fermentable organic matter to produce biogas and bio fertilizer.
An effective and integrated solid waste management system examines the waste reduction at source, resource recovery through separation, recycling through waste processing, waste transformation and environmentally sustainable disposal on land (Tchobanoglous et al., 1993 and Datta, 1997). Ali (1994) suggested factors to be considered while planning landfill scheme. The economy of operation is also a major factor which is considered at the planning stage. Pachauri (1999) highlighted that towns and cities generate as much as 48 million tons of MSW, the quantity will be 300million tons by 2047. Landfill sites are often associated with large uneven settlement as the results of biodegradation of MSW. The solid waste settlement always hinders the development of complete landfill sites, which is highly desirable particularly in land limited locations (El-Fadel et al., 1999). Francos and Bituro (1999) found innovative ways of improving SWM in the city Dar-es-salaam, Tanzania and included emergency cleanup campaigns privatization, community involvement, disposal site management and waste recycling. A work discussed in the Indian Institute of Science, Bangalore, website to suggest improved Solid Waste Management (SWM) practice for an area of about 180 hectares whose waste generation resembles a typical urban community, equivalent to a ward under city corporation's jurisdiction. Optimal SWM strategies for many kinds of wastes are proposed effectively with the help of field investigations and spatial analysis tools (Geographic Information System), 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 and suggested that the Waste management strategies should be in such a way as to perform the following functions
- Protection of environmental health.
- Promotion of environment quality.
- Supporting the efficiency and productivity of the economy
- Generation of employment and income.
Elshorbagy and Mohamed (2000) investigated the performance of a native soil available in arid areas blended with municipal solid waste compost as an infiltration barrier layer in landfill closure cap design. He evaluated experimentally the effect of organic decomposition and thermal fluctuation prevailing in the arid environment upon the changes in hydraulic conductivity. Municipal solid waste can be defined as post-consumer waste (Rampal and Salaria, 2001). Since municipal solid waste management Notification came into effect on 25th September, 2000, the need for technical information about landfills has increased. Soderman (2003) studied the effects of including indirect environmental impacts in waste management planning. Municipal waste contains various pollutants which contaminate the surrounding environment when dumped and disposed unscientifically (CPCB, 2003 a). Metin et al., (2003) evaluated municipal solid waste statistics and management practices including waste recovery and recycling initiatives in Turkey. Detailed data on solid waste management practices including collection, recovery and disposal, together with the results of cost analyses, had been presented. Morrissey and Browne (2004) reviewed the types of models that are currently being used in the area of municipal waste management and highlighted some major shortcomings of these models.
As per National Productivity Council, (2004), by 2021, MSW quantity will be around 124 – 140 million tons per annum, with the following changes in the composition of Indian solid waste between 2000 and 2025:
- Organic waste will go up from 42.5% to 60%
- Plastic will rise from 4% to 6%
- Metal will escalate from 1.9% to 4%
- Glass will increase from 2.1% to 3%
- Paper will go up from 5% to 15%
- Others (ash, sand, grit) will decrease from 40.3% to 12%
The siting and construction of a new SWM facility is a big challenge in Japan, because of limited space. Rahardyan et al., (2004) investigated public concern about SWM facilities in Japan and their attitudes towards such facilities. Koushki et al., (2004) studied that low energy and manpower costs are mainly responsible for the favorable cost of management, collection and transportation of residential waste in Kuwait. Kum et al., (2005) evaluated the constraints and shortfalls in the existing solid waste management system in Phnom Penh city and proposed appropriate strategies to make SWM in the city more effective and efficient to meet environmentally sound objectives.
Berkun et al., (2005) analyzed the implementation of a new solid waste management system at Istanbul with transfer stations, sanitary landfills and methane recovery and concluded that however it is difficult to implement along the Black Sea coast of Turkey because of more difficult topography, weaker administrative structures and the lower incomes of the inhabitants. Calco et al., (2005) studied a new methodology by which environmental diagnosis of landfill sites may be carried out. Rathi (2005) explored alternative approaches to municipal solid waste management and estimated the cost of waste management in Mumbai, India.
2.3 IMPACTS OF SOLID WASTE DISPOSAL
Calvert (1932) studied the contamination of groundwater by impounded garbage water. The effect of solid waste liquor contamination was noted in the nearest well located at 150m distance with an increase in hardness, calcium, magnesium and total solids. Impacts of landfill gases on air, water and soil were attributed to open dumps (Brunuel, 1971). The generated leachate can contain high levels of Bio-chemical oxygen demand (BOD), Chemical oxygen demand (COD), nitrate, chloride, alkalinity and trace elements that can degrade the quality of groundwater (Hughes et al., 1971 and Zanoni, 1972). The biochemical decomposition of organic matter in the waste generates gases such as methane, carbon dioxide, ammonia and hydrogen sulphide that can migrate through the unsaturated zone into adjacent terrains and cause potential hazards such as methane explosion (Mohsen, 1975 and Flower, 1976). The results of Olaniya et al., (1977) from studies on groundwater pollution by open solid waste dumps at Jaipur showed that the leachate from solid waste had higher concentrations of organic carbon, iron, manganese and dissolved solids.
The amount of pollution from solid waste based on studies carried out in India and for the sake of comparison and suitable modifications under Indian conditions, data from Switzerland is given in Table 2.1 (Indian standard 9533, 1980). The larger organic content in Indian refuse is reflected in higher pollutant levels.
Table 2.1 Pollution of groundwater by solid waste
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Winant et al., (1981) examined the effect of sanitary landfill leachate on soil chemical properties to a depth of 60cm and reported that the leachate supplied more calcium and magnesium than lime. Nicholson et al., (1983) studied groundwater pollution at a landfill in Ontario, Canada. The results revealed that calcium, sulphate and bi-carbonates were the dominant ions with maximum concentrations of 400mg/l, 2000mg/l and 1200 mg/l respectively. Total dissolved solids concentration was 4000mg/l. Sulphate and Iron also exceeded the recommended limits for drinking water. No heavy metals or other hazardous inorganic trace elements accumulated above the maximum limits for drinking water. Dayal et al., (1991) examined groundwater pollution by solid waste. Gopal et al., (1991) investigated the extent of groundwater pollution in Kanpur city by the leachate from solid waste.
Rao and Shantaram (1994) analysed the chemical characteristics of landfill runoff water. Rao and Shantaram et al., (1995) studied the groundwater pollution from solid waste dumps at Hyderabad and found that groundwater is not suitable for drinking purpose. Decomposing waste masses led to settlement and compaction of the dumped waste (Wall and Zeisis, 1995; Baldwin et al., 1998). Human health problems associated with MSW disposal had been studied by various researchers (Giroult, 1996 and Huren et al., 1999). The economic and environmental impacts of municipal solid waste management are dictated by the masses and volumes of materials moving through the various components of the municipal solid waste system (Douglas and Haith, 1998).
Khurshid et al., (1998) analyzed the effect of waste disposal on water quality which revealed that the concentration of trace elements exceeded the maximum permissible limit prescribed by World Health Organization.Kumar and Alappat, (2003) found out that the leachate composition varied considerably with the age of deposition of the waste at a municipal landfill site in New Delhi, India. Krishna et al., (2005) analyzed the effect of solid waste leachate on lateritic soil and concluded that leachate modified the soil chemical properties. Chandrasekar and Ayyappan (2006) studied the impact of municipal solid waste dumping on groundwater quality and concluded that higher amount of contamination was noticed in the water samples within 500m from the dumping site and were not suitable for drinking purpose.
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).
- Environmental pollution from waste leachates and gas evolving from dumped solid waste
- Health hazards to waste workers and pickers through direct contact with waste
- Chance of spreading of communicable diseases
- Unaesthetic appearance
- Poor living environment