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Municipal solid waste management in Nepal: practices and challenges
Waste Management 25 (2005) 555–562 www.elsevier.com/locate/wasman
Municipal solid waste management in Nepal: practices and challenges D. Pokhrel, T. Viraraghavan
*
Faculty of Engineering, University of Regina, 3737 Wascana Parkway, Regina, SK, Canada S4S 0A2 Accepted 26 January 2005 Available online 23 March 2005
Abstract Solid waste management in Kathmandu valley of Nepal, especially concerning the siting of landfills, has been a challenge for over a decade. The current practice of the illegal dumping of solid waste on the river banks has created a serious environmental and public health problem. The focus of this study was to carry out an evaluation of solid waste management in Nepal based on published information. The data showed that P70% of the solid wastes generated in Nepal are of organic origin. As such, composting of the solid waste and using it on the land is the best way of solid waste disposal. This will reduce the waste volume transported to the landfill and will increase its life. 2005 Elsevier Ltd. All rights reserved.
1. Introduction The environmentally acceptable management of municipal solid waste has become a global challenge due to limited resources, ever increasing population, rapid urbanization and industrialization worldwide. Statistics show that the world population reached 6 billion in 2001 with 46% of this population residing in urban areas. The urban population in developed nations was 75% of the total population in those countries, whereas the urban population in developing nations accounted for 40% of the total. The urban population in Asia was estimated to be 37% of the total Asian population (HMGN, MoPE, 2003). Global municipal solid waste (MSW) generated in 1997 was 0.49 billion tons with an estimated annual growth rate of 3.2–4.5% in developed nations and 2–3% in developing nations (Suocheng et al., 2001). Urban areas in Asia produced approximately 760,000 tons of municipal solid waste per day in 1998, which is expected to rise to 1.8 million tons by 2025. Local governments spent about US$25 billion for managing this waste in 1998 and this amount is ex*
Corresponding author. Tel.: +1 306 585 4094; fax: +1 306 585 4855. E-mail address: [email protected] (T. Viraraghavan).
0956-053X/$ - see front matter 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.wasman.2005.01.020
pected to double by 2025 (Mongkolnchaiarunya, 2005). China alone produced 0.14 billion tons of MSW in 1998. Singapore with a population of about 4 million disposes of about 8000 tons of solid waste daily (Bai and Sutanto, 2002). Nepal, a developing nation located in Asia, lies in the central part of the Himalayan Belt in between 2622 0 and 3027 0 north latitude and 8041 0 and 8812 0 east longitude. Nepal is characterized by a rugged topography, high relief and variable climate. The elevation of the country varies from 60 m in Terai (in Jhapa) to 8848 m (at Mount Everest) in the Himalayas within a short distance of 90–120 km (HMGN, MoWR, 2002). Nepal is divided into three major geographic regions: mountain (35.2%), hill (41.7%) and terai (flat land: 23.1%). The population distributions in these geographic regions are as follows: mountain 7.3%, hill 44.2% and terai 48.5% (HMGN, MoPE, 2003). The temperature and other climatic condition of these regions vary drastically: the temperature is found to vary from 25 C in the mountain region to 40 C in the terai region. A vertical geomorphology of Nepal is presented in Fig. 1. The total land area of Nepal is 147,181 km2 with a population of 23.2 million in 2001 (CBS, 2003). Nepal is undergoing a population explosion in its urban
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Fig. 1. Physiographic regions of Nepal (HMGN, MoWR, 2002).
ulation since 1952. A steep increase in urban population can be observed in the last decade. Obviously, solid waste production has also increased in a similar pattern. The solid waste generated by each municipality varied between approximately 1.3 and 123 tons/day according to the estimate made in 1999. The total amount of solid waste generated by all of the municipalities was estimated to be 427 tons/day (UNEP, 2001). No municipality outside the Kathmandu valley uses sanitary landfills or other means of sanitary disposal facilities for waste management. Municipalities located in Pokhara, Biratnagar, Birgunj and Nepalgunj are experiencing the stress of solid waste management in recent years. The traditional practice of managing solid waste in most of the municipalities includes open dumps in abandoned fields or on the bank of the rivers or streams (65– 100% of the MSW depending on the municipalities). Only a few municipalities are composting a small percentage of their waste and a small percentage of wastes is burnt (Mishra and Kayastha, 1998). This proportion of solid waste managed by composting or burning is insignificant compared to the huge amount of waste generated every day. Furthermore, the burning of waste is
15 Urban Population (%)
areas in recent times especially due to the rural migrants seeking employment, business and other opportunities in the cities. The urban population of Nepal is approximately 14% of the total population, which is low when compared with other developing nations. However, compared to the land area of the country and the available resources, this small urban population has become an enormous burden for the government in terms of environmental health, sanitation and environmental management. The urbanization in Nepal is rapid and haphazard, creating problems in facility management. The urban population in Nepal in 2001 was approximately 3.2 million (CBS, 2003) and it is estimated that the annual growth rate of the urban population in Nepal will be 6.5%, the highest growth rate in South Asia (UNEP, 2001). The percentage of the nationÕs budget allocated for environmental management and public health is very low. Solid waste management, especially finding proper sites for landfilling of the MSW generated by the municipalities inside the Kathmandu valley, has been a burning issue and topic of discussion for the media, government and non-governmental organizations in Nepal for more than a decade. The municipal solid waste generated inside the Kathmandu valley is being disposed in the Gokarna Landfill (near the Tribhuwan International Airport) and along the banks of the rivers Bagmati and Bishnumati. Therefore, the impact of solid waste disposal sites on the environment and public health is considerable. This paper presents an evaluation of the solid waste management in Nepal based on published information.
12 9 6 3
2. Solid waste generation in Nepal At the present, Nepal has 58 municipalities with the population of individual municipalities varying from 14,000 to 700,000 according to an estimate made in 1999. Fig. 2 depicts the percentage growth of urban pop-
0 1951
1961
1971
1981
1991
2001
Year Fig. 2. Urban population as percentage of total population in Nepal (HMGN, MoPE, 2003).
D. Pokhrel, T. Viraraghavan / Waste Management 25 (2005) 555–562
not carried out through proper incineration systems; instead the waste is burned on an open field. The problem of solid waste management in the municipalities located on the outskirts of Kathmandu valley is not as severe as in the municipalities inside Kathmandu valley. Kathmandu valley occupies only about 0.5% of the total land area of Nepal but it has 10% of the national population. Therefore, the management of solid waste and the challenges experienced by the municipalities in Kathmandu valley are discussed in detail.
557
1500
Population ('000)
1200 900 600 300 0 1971
3. Solid waste composition inside the Kathmandu valley
1981
1991 Year
2001
2011
Fig. 3. Municipal population growth in the Kathmandu valley (Sharma and Kayastha, 1998; CBS, 2003).
Kathmandu valley lies at the foot of the Himalayas. The temperature of the valley varies from freezing (slightly below zero) in winter to a high of about 30 C in the summer. The mean annual temperature of the valley is about 18 C and the average annual precipitation is 1400 mm. The total amount of solid waste generated in the Kathmandu valley is estimated to be about 291 tons/day (Joshi, 2003). However, the Solid Waste Management and Resource Mobilization Center (SWMRMC, 2000) estimated that the amount of waste generated in the Kathmandu valley could be 350 tons/ day by the year 2002. In another report by Timilsina (2001), the average waste generation rate was stated to be 540 m3/day, with 72% of the total waste generated destined for final disposal in a landfill site. Based upon the estimate of 1999, about 40% of the solid waste is generated from the Kathmandu valley alone (UNEP, 2001). A study in 1991 showed the average amount of solid waste generated by people of Kathmandu valley varied from 0.25 to 0.5 kg/cap/day. In another study by IUCN in 1997, the amount of solid waste generated in Kathmandu valley was estimated to be 0.565 kg/ cap/day (Mishra and Kayastha, 1998). The municipal population growth in the Kathmandu valley in recent
decades is presented in Fig. 3. The composition of the MSW generated in the Kathmandu Valley is presented in Table 1. Data in Table 1 show that there has been a change in the solid waste composition over time. The quantity of the plastic waste has increased compared with the previous years. Sharma and Gharti Chetri (1995) reported that the organic fraction of the solid waste generated had decreased and suggested transforming the solid waste into fire briquettes, which can be used as fuel. However, due to NepalÕs economic situation, this may not be realistic. The composition of the solid waste varies with cities and countries depending on the standard of living, life style, social and religious tradition and the eating habits of the people. The contribution of the solid waste by the industrial sector is smaller compared to the municipal solid waste in Nepal. Since industrialization is slow in Nepal, the amount of the hazardous waste generated is normally insignificant. However, the small quantity is not even disposed of safely. It is considered that hospital wastes,
Table 1 Characteristics of the solid waste in Kathmandu valley Components
Waste composition (%wt) a
Organic materials Paper Plastics Glass Metals Textiles Rubber and leather Wood Dust/Construction debris Others a b c d
1976
67.8 6.5 0.3 1.3 4.9 6.5 0 2.7 10 –
a
a
60 19.3 3.6 3.4 3.4 5.3 0 1.6 3.4 –
67.5 6 2.6 4 2.2 2.7 0 0 15 –
1981
UNEP (2001). Jindal et al. (1997). http://www.fern.org.np/topics/swaste.htm#swaste (2000). Joshi (2003).
1985
a
a
58.1 6.2 2.0 1.6 0.4 2 0.4 0.5 28.9 –
65.0 4 5 1 1 3.0 1 3 17 –
1988
1995
a
b
c
d
67.5 8.8 11.4 1.6 0.9 3.6 0.3 0.6 5.3 –
65.5 7.3 5.4 3.1 2.2 1.7 1.6 1.4 9.1 1.7
69.84 8.5 9.17 2.5 – 3.02 0.6 0.73 – 0.23
70 8.5 9.5 2.5 – 3 – – 4.5 2
1999
1997
2000
2003
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obsolete pesticides and a few industrial wastes are the major sources of the hazardous waste in Nepal. The waste generated by a patient in a health institution was estimated to be 5.71 kg/day of which 30% was hazardous in nature (State of the Environment Report, 2000). Incinerators were installed in some of the private and public hospitals in Kathmandu as well as outside the valley. However, some of them are not in working condition. Due to the lack of separate collection and disposal facilities, there is a fair chance that these wastes could be mixed with the municipal solid waste (ENPHO, 2001). The daily collection of hazardous waste by the Kathmandu municipality was reported as 1400 kg/ day (unpublished information collected from the SWMRMC office, Kathmandu). It is not known how much hazardous waste is generated by other municipalities inside the Kathmandu valley. In a study conducted in 1999, the amount of hazardous waste generated in Nepal was estimated to be 500 tons/year (UNEP, 2001). This report indicated that the total amount of the dry cells disposed per year is 225 tons and the total consumption of the pesticides per year is about 55 tons. So the problem of lead and pesticide poisoning due to unsafe disposal is one of the major challenges in Nepal. The report also stated that about 67 tons of the obsolete pesticides are stored in different parts of the country in unsafe condition. Based on a survey in 1995, it was reported that only 38% of the farmers buried or burned old or unused pesticides. The rest were disposed of in waste containers as part of solid waste in the open fields (UNEP, 2001).
4. Solid waste management practices The earlier practice of solid waste management by the city dwellers in the Kathmandu valley is not clearly documented. With a small population, low amount of industrial activity inside the Kathmandu valley and with abandoned land available, the waste generated was either dumped on the river banks on the outskirts of the urban core or collected, decomposed and used as an organic manure in the agricultural field. The collection and disposal of these wastes was assigned to kuchikars, which in Nepalese means ÔcleanersÕ. The old urban settlement of the Kathmandu valley consists of open space or courtyards between houses which usually have a common entrance. Parts of these spaces were even used for the collection of waste (usually food waste or other organic wastes) on a temporary basis. The collection and disposal cost of these wastes were shared equally by the surrounding households (Thapa, 1998). As time passed, the population increased, and with it the amount of uncollected solid waste. Realizing the problem, Prime Minister Chandra Samsher established a safai adda (sanitary office) in 1891 (Thapa, 1998). This
agency employed kuchikars for collection and disposal of the solid wastes from the courtyards, roads and alleys. In 1950, the three towns of Kathmandu, Patan and Bhaktapur were incorporated as municipalities and the management of the solid waste was the responsibility of the respective municipalities. These municipalities employed kuchikars for collection of the solid waste and tractors were used to dispose of the waste along the Bagmati and Bishnumati rivers. To the public, this meant that they were no longer responsible for the management of the solid waste. This weakened the traditional practice of waste management through active community participation (Thapa, 1998). Before the 1980s, solid waste management did not pose a serious problem. The MSW was managed jointly by the city residents and the municipalities. Solid wastes were collected and disposed of by municipal labour force ÔkuchikarsÕ. In 1981, the responsibility to manage the solid waste of Kathmandu valley was handed over to the Solid Waste Management and Resource Mobilization Center (SWMRMC), funded by German Technical Cooperation Agency (GTZ). Part of the MSW was recycled and part of it was processed to make organic fertilizer by establishing a processing plant at Teku, Kathmandu. In 1986 a sanitary landfill was developed at Gokarna (near the Tribhuvan International Airport, Kathmandu) where most of the solid waste was disposed. After the restoration of democracy in Nepal in 1990, the one-party Panchayat system collapsed and the political power was handed over to the various political parties. The previous management system in the SWMRMC was also changed by the successive governments and the landfill was operated haphazardly until January 1994 (NESS, 1996). In 1993, GTZ withdrew the financial support and handed over the management to the municipal authority. The role of the central government and the municipality in the management of solid waste was to some extent unclear and a dispute arose regarding the management of the solid waste. The crisis was resolved with the role of the central government directed towards the provision of the landfill site and the municipalities given the responsibility for disposal including daily waste management (Timilsina, 2001). The local people around the landfill site in Gokarna prevented the solid waste carriers (trucks) from entering the landfill site. During this period (1990–1994), the solid waste of the cities in Kathmandu valley was stockpiled on a few occasions and the cities were looking unsightly in many areas. It affected public life and, of course, the tourism industry badly. The solid waste was even dumped once in a public place (Tundikhel) by the Kathmandu municipality as the government could not provide a proper place to dispose of the material. The landfill site at Gokarna was closed for nearly 2
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years due to strong public objection (until November 1995), when it was reopened and operated until 1998. After the closure of the landfill site at Gokarna, the solid waste of the Kathmandu valley was dumped on the banks of the rivers around the city. The waste management authorities started using the waste as a filling material for road construction along the bank of the Bagmati River without considering the adverse effect on the environment and public health (Timilsina, 2001). From 1994, a landfill site was developed on the bank of the Bishnumati River near Shobhabhagavati, in Kathmandu. Currently, the solid waste of the Kathmandu valley is being landfilled on the bank of the Bagmati River near Balkhu in Kathmandu without considering the effect on the water resources and the health impact on the surrounding settlement. Selection and development of a sanitary landfill site to dispose of solid waste was a major challenge for the Nepali government for many years. Now, the government has decided to develop a sanitary landfill site at Okharpouawa in Nuwakot district, approximately 26 km away from Kathmandu. It is estimated that the solid waste of the Kathmandu valley can be landfilled in this site for the next 50 years (Mishra and Kayastha, 1998). The construction of an access road to this site is in progress. Since the road passes through a mountainous area, the operation and maintenance cost of the road in monsoon season and the transfer cost of the solid waste may become a financial burden to the municipalities.
5. Impact on the environment and public health In a survey, 59% of the respondents in Nepal stated that they consider solid waste a major problem (ENPHO, 2001). Normally, this kind of survey data reflects the public knowledge and awareness of the environmental health aspect. Al-Yaqout et al. (2002) carried out a survey on the public perception on the landfilling and its public health aspect in Kuwait. The study revealed that less than 50% of the respondents were aware of the public health impact of the landfilling, and visual appearance of the landfill scored the lowest in importance. Environmental impacts of poor solid waste management lead to the deterioration of ground and surface water quality, as well as air and land pollution. The impact depends on the waste composition and disposal practices. The traditional landfill practice produces various landfill gases such as methane, carbon dioxide, carbon monoxide, nitrogen, hydrogen sulfide and ammonia. The percentage of green house gases (methane and carbon dioxide: 40–60%) is high (Tchobanoglous et al., 1993). Some of these gases have a pungent odour (ammonia and hydrogen sulfide) and are poison-
559
ous. If a proper collection or venting system is not provided, these hazardous fumes can create a health risk for the population near the landfill. In Nepal, the composition of the gas produced from the landfills and the health effects on the waste workers exposed to the landfill and the population nearby are unknown. An environmental study conducted by NESS in 1996 reported that the implementation and the operational phase of the Gokarna Landfill was not carried out properly as planned. This report indicated that infrastructure developed for landfilling such as landfill liners, leachate control, collection and treatment facility, gas control, collection and use facility, surface water drainage facility, compaction, final cover soil and the environmental monitoring facilities was not adequate. The same report indicated that inadequacy of aesthetic consideration in implementation, lack of public health and safety consideration, inadequate animal and bird control and poor maintenance were the major reasons that Gokarna Landfill poses a threat to public health. The characteristics of the leachate from the Gokarna Landfill are presented in Table 2. The report by NESS (1996) indicated that various water quality (ground and surface water) analyses were carried out by different organizations at different times to observe the contamination of water resources. The water quality analysis conducted by GTZ showed that there was no measurable contamination of ground and surface waters downstream of the disposal site either by inorganic, organic or heavy metals pollution (NESS, 1996). NESS (1996) conducted analysis of groundwater at seven locations and two spring water sources around the landfill site. It is very interesting that even with that poor management and operation of the landfill development, the water quality of the most of the wells were found to be unpolluted. Six out of the seven groundwater test results showed a high iron level (1.07–2.9 mg/L) and one spring source showed an iron level of 4.6 mg/L. It is not known whether the iron content was high in the groundwater itself. The lead content was slightly higher than the limit set by the WHO in one of the seven groundwater samples and in one of the two spring water sources; otherwise, water quality was found to be good (NESS, 1996). However, Khadka (1998) speculated that there was a high risk of groundwater contamination near the Gokarna Landfill area as the underlying soil is comprised of sand and silt with a low cation exchange capacity. This is supported by the fact that the solid waste was laid without liners at the bottom; soil cover was also very poor, aggravating percolation of the surface runoff through the landfill thereby increasing the quantity of leachate produced. Leachate collection and control and the protection against the erosion of the waste dumped were virtually non-existent in Bishnumati Landfill. The landfill was poorly developed and no consideration was taken to
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Table 2 Characteristics of leachate from the Gokarna Landfill and Bishnumati Landfill Parametersfl
Gokarna Landfill (NESS, 1996)
Bishnumati Landfill
(1) Mar. 1996
(2) Dec. 1988
(3) 1988
(4) 1988
Sharma et al. (1995)
PH Conductivity (lS/cm) Color (Chromacity Unit) Turbidity (NTU) TSS (mg/L) TDS (mg/L) Total alkalinity as CaCO3 (mg/L) Total acidity as alkali consumption (mg/L) Total hardness as CaCO3 (mg/L) Calcium (mg/L) Magnesium (mg/L) Chloride (mg/L) Phosphate (mg/L) Total phosphorus (mg/L) Ammonia-N (mg/L) Nitrite-N (mg/L) Nitrate-N (mg/L) Organic-N (mg/L) Sodium (mg/L) Potassium (mg/L) Lead (mg/L) Copper (mg/L) Nickel (mg/L) Chromium (mg/L) Zinc (mg/L) Cadmium (mg/L) Iron (mg/L) Manganese (mg/L) BOD (mg/L) COD (mg/L)
6.75 13,500 273 640 1144 30,036 8798 19.71 9500 2700 656.1 24,046 0.76 0.80 808.0 0.98 2.73 534 618.25 1625 0.32 0.07 0.55 0.38 0.26 0.03 323.11 39.74 3500 45,500
7.10 10,050 – – 2923a – – – – 512 166.4 845 3 – 343 CND CND – – 1110 0.10 0.1 3.7 0.6 0.31 0.3 30.7 5.4 – –
– 2090 – – – – – – – – – 190 – – – – – – 112 189 – – – – – – 2.6 – – –
7.6 10,255 – – – – – – – – – 4463 – – 485 – – – – – – – – – – – – – 5003 7148
7.53 8790 90 700 – – 4621 – 2130 455 242 1290 0.3 – 518 0.02 2.7 1239 953 1127 0.28 0.14 0.13 1.06 0.65 0.01 9.1 3.8 – 3205
Note: The data on the leachate at Gokarna Landfill were from different sources: (1) NESS; (2) Asian Institute of Technology (AIT); (3) Presenius; (4) DISWI. a Volatile solids.
safe-guard public health of the surrounding area (Sharma et al., 1995). The leachate was discharged to the River Bishnumati, causing contamination of the river water and this had an adverse impact on agricultural resources downstream. The Bagmati and Bishnumati rivers are of religious importance for Hindus in Nepal. Solid waste dumping on the banks is not the only source of pollution of these rivers. Poor wastewater management is the major reason for river pollution. Alternate measures should be considered instead of dumping the waste in the rivers.
6. Discussion Political instability in the country, especially after the restoration of democracy in 1990 contributed in some measure to the poor environmental management of solid waste. The successive governments after restoration of democracy were engaged in the intra and extra political disputes, paying less attention to infrastructure development and environmental management. There was little political commitment to resolve the crisis. Poor institu-
tional experience, lack of strong legislation and enforcement, and poor financial status of both government and the municipalities were the cumulative reasons for the poor solid waste management. Thapa (1998) suggested that the collection of a service fee, involvement of the private sector in waste management, environmental awareness building in the public and the enforcement of stringent environmental legislation were necessary for sustainable management of solid waste. Nepal needs to learn from the experiences of other countries in the practice of managing solid waste. Post (1999) suggested the involvement of the private sector with close monitoring by the government to manage the solid waste in Kumasi, Ghana. MexicoÕs experience in managing the municipal solid waste was presented by Buenrostro and Bocco (2003). The authors pointed out that inadequate resources of municipalities such as financial, technical and human infrastructure were the reasons behind the improper management of solid waste in Mexico. Technically, the composition of the solid waste is an important consideration in deciding on the type of disposal method to adopt for a particular community.
D. Pokhrel, T. Viraraghavan / Waste Management 25 (2005) 555–562
Metin et al. (2003) reported that about 50% of the waste generated in Turkey was of organic origin. The authors suggested a separate collection system for the recyclable solid waste. The recyclable solid waste consisted of onefourth of the total municipal solid waste. Mongkolnchaiarunya (2005) reported on a successful story of an incentive program ÔGarbage for EggÕ launched in Yala municipality, Thailand. A total of 66.8 tons of the recyclable waste was collected from the local area through this program. The composting of solid waste is one of the sustainable ways of managing it if a large fraction of the waste is organic in nature. Since more than 70% of the solid waste generated in Nepal is of organic origin, composting is one of the best ways to manage solid waste. Timilsina (2001) reported that 21% of KathmanduÕs waste is recyclable and 62% of the waste is compostable. Aerobic composting is gaining in importance worldwide as it has substantial benefits over traditional landfilling. Read et al. (2001) reported on the enormous advantage of aerobic landfills compared to conventional anaerobic landfilling. The authors concluded that the aerobic approach could be implemented in new as well as existing landfills to significantly reduce costs, leachate and green house gas production rate, and would rapidly stabilize the waste mass. Leachate recirculation in the landfill is an option to reduce the environmental impact of a landfill, increasing the microbial population inside the compost reactor or in the landfill and substantially reducing the waste mass. Aerobic biological pre-treatment of the MSW had been carried out in Germany since 1970 to decrease waste mass, increase landfill density, improve leachate quality and reduce the attraction to birds (Read et al., 2001). Aerobic landfilling had received considerable attention in Germany, Japan, USA, India and other parts of the world. Successful aerobic composting of the municipal solid waste in Bombay, India (capacity 300 tons/day processing capacity) was established in 1992 by a private company. The compost is being sold at a rate of Rs. 2 kg1. Similar composting plants were expected to be established in Banglore, Calcutta, Thane, Chandigarh, Gwalior, Solan and Delhi (Gupta et al., 1998). Nearly all the Indian cities dispose of their waste by simple dumping: only 8.6% practice composting whereas 89.8% use land dumping and 1.6% use other ways of disposal (Gupta et al., 1998). Hamer (2003) suggested composting as the best option to ensure public health and environmental safety in managing solid waste. The other means of treatment are often more expensive than landfilling. For example, 73% of the waste generated in Singapore are disposed of by incineration. The waste volume reduction by incineration was about 90%. However, the cost of incineration was about 6–7 times higher than the cost of landfill (Bai and Sutanto, 2002).
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7. Conclusions The following conclusions were drawn from this study: 1. The composition of the solid waste generated in Kathmandu and other municipalities in Nepal is dominated (70%) by organic material. Composting of the solid waste and using the compost as an organic fertilizer is a sustainable way of managing solid wastes in Nepal. 2. The source separation of the recyclable material such as metals and plastics by increasing awareness among the public is important to reduce the waste treatment cost. 3. Involvement of the private sector in waste management is required for sustainable management of solid waste in Nepal. The concept of public private partnership (PPP) may be suitable in order to develop public understanding of their investment in waste management. 4. Municipalities must enforce strict regulations to prevent illegal dumping of solid waste on riverbanks and in public places.
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Sharma, T., Gharti Chetri (G.C.)., H., 1995. Study on resource recovery aspects of solid waste (fuel briquetting option). In: Research on Environmental Pollution and Management. A Publication of Nepal Environmental and Scientific Services, Kathmandu, Nepal, pp. 61–67. Sharma, T., Upadhyaya, N.P., Shahi, K.B., 1995. Leachate characteristics of Bishnumati Landfill Site. In: Research on Environmental Pollution and Management. A Publication of Nepal Environmental and Scientific Services, Kathmandu, Nepal, pp. 52–58. State of the Environment, 2000. State of the environment of Nepal 2000. Available from:. Suocheng, D., Tong, K.W., Yuping, W., 2001. Municipal solid waste management in China: using commercial management to solve a growing problem. Utilities Policy 10, 7–11. SWMRMC, 2000. Request for the proposal of solid waste management in Kathmandu Valley. Solid Waste Management and Resource Mobilization Centre (SWMRMC), Kathmandu, Nepal. Tchobanoglous, G., Theisen, H., Vigil, S., 1993. Integrated Solid Waste Management: Engineering Principles and Management Issues. McGraw-Hill, New York, USA, pp. 382–383. Thapa, G.B., 1998. Lessons learned from solid waste management in Kathmandu, Nepal. Habitat International 22 (2), 97–114. Timilsina, B.P., 2001. Public and private sector involvement in municipal solid waste management: an overview of strategy, policy and practices. A Journal of the Environment 6 (7), 68–77, A Publication of Ministry of Population and Environment, Nepal. UNEP, 2001. Nepal: state of the environment 2001. Published by United Nations Environment Programme (UNEP) in collaboration with MoPE HMGN, SACEP, ICIMOD and NORAD.
Municipal solid waste management in Nepal: practices and challenges D. Pokhrel, T. Viraraghavan
*
Faculty of Engineering, University of Regina, 3737 Wascana Parkway, Regina, SK, Canada S4S 0A2 Accepted 26 January 2005 Available online 23 March 2005
Abstract Solid waste management in Kathmandu valley of Nepal, especially concerning the siting of landfills, has been a challenge for over a decade. The current practice of the illegal dumping of solid waste on the river banks has created a serious environmental and public health problem. The focus of this study was to carry out an evaluation of solid waste management in Nepal based on published information. The data showed that P70% of the solid wastes generated in Nepal are of organic origin. As such, composting of the solid waste and using it on the land is the best way of solid waste disposal. This will reduce the waste volume transported to the landfill and will increase its life. 2005 Elsevier Ltd. All rights reserved.
1. Introduction The environmentally acceptable management of municipal solid waste has become a global challenge due to limited resources, ever increasing population, rapid urbanization and industrialization worldwide. Statistics show that the world population reached 6 billion in 2001 with 46% of this population residing in urban areas. The urban population in developed nations was 75% of the total population in those countries, whereas the urban population in developing nations accounted for 40% of the total. The urban population in Asia was estimated to be 37% of the total Asian population (HMGN, MoPE, 2003). Global municipal solid waste (MSW) generated in 1997 was 0.49 billion tons with an estimated annual growth rate of 3.2–4.5% in developed nations and 2–3% in developing nations (Suocheng et al., 2001). Urban areas in Asia produced approximately 760,000 tons of municipal solid waste per day in 1998, which is expected to rise to 1.8 million tons by 2025. Local governments spent about US$25 billion for managing this waste in 1998 and this amount is ex*
Corresponding author. Tel.: +1 306 585 4094; fax: +1 306 585 4855. E-mail address: [email protected] (T. Viraraghavan).
0956-053X/$ - see front matter 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.wasman.2005.01.020
pected to double by 2025 (Mongkolnchaiarunya, 2005). China alone produced 0.14 billion tons of MSW in 1998. Singapore with a population of about 4 million disposes of about 8000 tons of solid waste daily (Bai and Sutanto, 2002). Nepal, a developing nation located in Asia, lies in the central part of the Himalayan Belt in between 2622 0 and 3027 0 north latitude and 8041 0 and 8812 0 east longitude. Nepal is characterized by a rugged topography, high relief and variable climate. The elevation of the country varies from 60 m in Terai (in Jhapa) to 8848 m (at Mount Everest) in the Himalayas within a short distance of 90–120 km (HMGN, MoWR, 2002). Nepal is divided into three major geographic regions: mountain (35.2%), hill (41.7%) and terai (flat land: 23.1%). The population distributions in these geographic regions are as follows: mountain 7.3%, hill 44.2% and terai 48.5% (HMGN, MoPE, 2003). The temperature and other climatic condition of these regions vary drastically: the temperature is found to vary from 25 C in the mountain region to 40 C in the terai region. A vertical geomorphology of Nepal is presented in Fig. 1. The total land area of Nepal is 147,181 km2 with a population of 23.2 million in 2001 (CBS, 2003). Nepal is undergoing a population explosion in its urban
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Fig. 1. Physiographic regions of Nepal (HMGN, MoWR, 2002).
ulation since 1952. A steep increase in urban population can be observed in the last decade. Obviously, solid waste production has also increased in a similar pattern. The solid waste generated by each municipality varied between approximately 1.3 and 123 tons/day according to the estimate made in 1999. The total amount of solid waste generated by all of the municipalities was estimated to be 427 tons/day (UNEP, 2001). No municipality outside the Kathmandu valley uses sanitary landfills or other means of sanitary disposal facilities for waste management. Municipalities located in Pokhara, Biratnagar, Birgunj and Nepalgunj are experiencing the stress of solid waste management in recent years. The traditional practice of managing solid waste in most of the municipalities includes open dumps in abandoned fields or on the bank of the rivers or streams (65– 100% of the MSW depending on the municipalities). Only a few municipalities are composting a small percentage of their waste and a small percentage of wastes is burnt (Mishra and Kayastha, 1998). This proportion of solid waste managed by composting or burning is insignificant compared to the huge amount of waste generated every day. Furthermore, the burning of waste is
15 Urban Population (%)
areas in recent times especially due to the rural migrants seeking employment, business and other opportunities in the cities. The urban population of Nepal is approximately 14% of the total population, which is low when compared with other developing nations. However, compared to the land area of the country and the available resources, this small urban population has become an enormous burden for the government in terms of environmental health, sanitation and environmental management. The urbanization in Nepal is rapid and haphazard, creating problems in facility management. The urban population in Nepal in 2001 was approximately 3.2 million (CBS, 2003) and it is estimated that the annual growth rate of the urban population in Nepal will be 6.5%, the highest growth rate in South Asia (UNEP, 2001). The percentage of the nationÕs budget allocated for environmental management and public health is very low. Solid waste management, especially finding proper sites for landfilling of the MSW generated by the municipalities inside the Kathmandu valley, has been a burning issue and topic of discussion for the media, government and non-governmental organizations in Nepal for more than a decade. The municipal solid waste generated inside the Kathmandu valley is being disposed in the Gokarna Landfill (near the Tribhuwan International Airport) and along the banks of the rivers Bagmati and Bishnumati. Therefore, the impact of solid waste disposal sites on the environment and public health is considerable. This paper presents an evaluation of the solid waste management in Nepal based on published information.
12 9 6 3
2. Solid waste generation in Nepal At the present, Nepal has 58 municipalities with the population of individual municipalities varying from 14,000 to 700,000 according to an estimate made in 1999. Fig. 2 depicts the percentage growth of urban pop-
0 1951
1961
1971
1981
1991
2001
Year Fig. 2. Urban population as percentage of total population in Nepal (HMGN, MoPE, 2003).
D. Pokhrel, T. Viraraghavan / Waste Management 25 (2005) 555–562
not carried out through proper incineration systems; instead the waste is burned on an open field. The problem of solid waste management in the municipalities located on the outskirts of Kathmandu valley is not as severe as in the municipalities inside Kathmandu valley. Kathmandu valley occupies only about 0.5% of the total land area of Nepal but it has 10% of the national population. Therefore, the management of solid waste and the challenges experienced by the municipalities in Kathmandu valley are discussed in detail.
557
1500
Population ('000)
1200 900 600 300 0 1971
3. Solid waste composition inside the Kathmandu valley
1981
1991 Year
2001
2011
Fig. 3. Municipal population growth in the Kathmandu valley (Sharma and Kayastha, 1998; CBS, 2003).
Kathmandu valley lies at the foot of the Himalayas. The temperature of the valley varies from freezing (slightly below zero) in winter to a high of about 30 C in the summer. The mean annual temperature of the valley is about 18 C and the average annual precipitation is 1400 mm. The total amount of solid waste generated in the Kathmandu valley is estimated to be about 291 tons/day (Joshi, 2003). However, the Solid Waste Management and Resource Mobilization Center (SWMRMC, 2000) estimated that the amount of waste generated in the Kathmandu valley could be 350 tons/ day by the year 2002. In another report by Timilsina (2001), the average waste generation rate was stated to be 540 m3/day, with 72% of the total waste generated destined for final disposal in a landfill site. Based upon the estimate of 1999, about 40% of the solid waste is generated from the Kathmandu valley alone (UNEP, 2001). A study in 1991 showed the average amount of solid waste generated by people of Kathmandu valley varied from 0.25 to 0.5 kg/cap/day. In another study by IUCN in 1997, the amount of solid waste generated in Kathmandu valley was estimated to be 0.565 kg/ cap/day (Mishra and Kayastha, 1998). The municipal population growth in the Kathmandu valley in recent
decades is presented in Fig. 3. The composition of the MSW generated in the Kathmandu Valley is presented in Table 1. Data in Table 1 show that there has been a change in the solid waste composition over time. The quantity of the plastic waste has increased compared with the previous years. Sharma and Gharti Chetri (1995) reported that the organic fraction of the solid waste generated had decreased and suggested transforming the solid waste into fire briquettes, which can be used as fuel. However, due to NepalÕs economic situation, this may not be realistic. The composition of the solid waste varies with cities and countries depending on the standard of living, life style, social and religious tradition and the eating habits of the people. The contribution of the solid waste by the industrial sector is smaller compared to the municipal solid waste in Nepal. Since industrialization is slow in Nepal, the amount of the hazardous waste generated is normally insignificant. However, the small quantity is not even disposed of safely. It is considered that hospital wastes,
Table 1 Characteristics of the solid waste in Kathmandu valley Components
Waste composition (%wt) a
Organic materials Paper Plastics Glass Metals Textiles Rubber and leather Wood Dust/Construction debris Others a b c d
1976
67.8 6.5 0.3 1.3 4.9 6.5 0 2.7 10 –
a
a
60 19.3 3.6 3.4 3.4 5.3 0 1.6 3.4 –
67.5 6 2.6 4 2.2 2.7 0 0 15 –
1981
UNEP (2001). Jindal et al. (1997). http://www.fern.org.np/topics/swaste.htm#swaste (2000). Joshi (2003).
1985
a
a
58.1 6.2 2.0 1.6 0.4 2 0.4 0.5 28.9 –
65.0 4 5 1 1 3.0 1 3 17 –
1988
1995
a
b
c
d
67.5 8.8 11.4 1.6 0.9 3.6 0.3 0.6 5.3 –
65.5 7.3 5.4 3.1 2.2 1.7 1.6 1.4 9.1 1.7
69.84 8.5 9.17 2.5 – 3.02 0.6 0.73 – 0.23
70 8.5 9.5 2.5 – 3 – – 4.5 2
1999
1997
2000
2003
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obsolete pesticides and a few industrial wastes are the major sources of the hazardous waste in Nepal. The waste generated by a patient in a health institution was estimated to be 5.71 kg/day of which 30% was hazardous in nature (State of the Environment Report, 2000). Incinerators were installed in some of the private and public hospitals in Kathmandu as well as outside the valley. However, some of them are not in working condition. Due to the lack of separate collection and disposal facilities, there is a fair chance that these wastes could be mixed with the municipal solid waste (ENPHO, 2001). The daily collection of hazardous waste by the Kathmandu municipality was reported as 1400 kg/ day (unpublished information collected from the SWMRMC office, Kathmandu). It is not known how much hazardous waste is generated by other municipalities inside the Kathmandu valley. In a study conducted in 1999, the amount of hazardous waste generated in Nepal was estimated to be 500 tons/year (UNEP, 2001). This report indicated that the total amount of the dry cells disposed per year is 225 tons and the total consumption of the pesticides per year is about 55 tons. So the problem of lead and pesticide poisoning due to unsafe disposal is one of the major challenges in Nepal. The report also stated that about 67 tons of the obsolete pesticides are stored in different parts of the country in unsafe condition. Based on a survey in 1995, it was reported that only 38% of the farmers buried or burned old or unused pesticides. The rest were disposed of in waste containers as part of solid waste in the open fields (UNEP, 2001).
4. Solid waste management practices The earlier practice of solid waste management by the city dwellers in the Kathmandu valley is not clearly documented. With a small population, low amount of industrial activity inside the Kathmandu valley and with abandoned land available, the waste generated was either dumped on the river banks on the outskirts of the urban core or collected, decomposed and used as an organic manure in the agricultural field. The collection and disposal of these wastes was assigned to kuchikars, which in Nepalese means ÔcleanersÕ. The old urban settlement of the Kathmandu valley consists of open space or courtyards between houses which usually have a common entrance. Parts of these spaces were even used for the collection of waste (usually food waste or other organic wastes) on a temporary basis. The collection and disposal cost of these wastes were shared equally by the surrounding households (Thapa, 1998). As time passed, the population increased, and with it the amount of uncollected solid waste. Realizing the problem, Prime Minister Chandra Samsher established a safai adda (sanitary office) in 1891 (Thapa, 1998). This
agency employed kuchikars for collection and disposal of the solid wastes from the courtyards, roads and alleys. In 1950, the three towns of Kathmandu, Patan and Bhaktapur were incorporated as municipalities and the management of the solid waste was the responsibility of the respective municipalities. These municipalities employed kuchikars for collection of the solid waste and tractors were used to dispose of the waste along the Bagmati and Bishnumati rivers. To the public, this meant that they were no longer responsible for the management of the solid waste. This weakened the traditional practice of waste management through active community participation (Thapa, 1998). Before the 1980s, solid waste management did not pose a serious problem. The MSW was managed jointly by the city residents and the municipalities. Solid wastes were collected and disposed of by municipal labour force ÔkuchikarsÕ. In 1981, the responsibility to manage the solid waste of Kathmandu valley was handed over to the Solid Waste Management and Resource Mobilization Center (SWMRMC), funded by German Technical Cooperation Agency (GTZ). Part of the MSW was recycled and part of it was processed to make organic fertilizer by establishing a processing plant at Teku, Kathmandu. In 1986 a sanitary landfill was developed at Gokarna (near the Tribhuvan International Airport, Kathmandu) where most of the solid waste was disposed. After the restoration of democracy in Nepal in 1990, the one-party Panchayat system collapsed and the political power was handed over to the various political parties. The previous management system in the SWMRMC was also changed by the successive governments and the landfill was operated haphazardly until January 1994 (NESS, 1996). In 1993, GTZ withdrew the financial support and handed over the management to the municipal authority. The role of the central government and the municipality in the management of solid waste was to some extent unclear and a dispute arose regarding the management of the solid waste. The crisis was resolved with the role of the central government directed towards the provision of the landfill site and the municipalities given the responsibility for disposal including daily waste management (Timilsina, 2001). The local people around the landfill site in Gokarna prevented the solid waste carriers (trucks) from entering the landfill site. During this period (1990–1994), the solid waste of the cities in Kathmandu valley was stockpiled on a few occasions and the cities were looking unsightly in many areas. It affected public life and, of course, the tourism industry badly. The solid waste was even dumped once in a public place (Tundikhel) by the Kathmandu municipality as the government could not provide a proper place to dispose of the material. The landfill site at Gokarna was closed for nearly 2
D. Pokhrel, T. Viraraghavan / Waste Management 25 (2005) 555–562
years due to strong public objection (until November 1995), when it was reopened and operated until 1998. After the closure of the landfill site at Gokarna, the solid waste of the Kathmandu valley was dumped on the banks of the rivers around the city. The waste management authorities started using the waste as a filling material for road construction along the bank of the Bagmati River without considering the adverse effect on the environment and public health (Timilsina, 2001). From 1994, a landfill site was developed on the bank of the Bishnumati River near Shobhabhagavati, in Kathmandu. Currently, the solid waste of the Kathmandu valley is being landfilled on the bank of the Bagmati River near Balkhu in Kathmandu without considering the effect on the water resources and the health impact on the surrounding settlement. Selection and development of a sanitary landfill site to dispose of solid waste was a major challenge for the Nepali government for many years. Now, the government has decided to develop a sanitary landfill site at Okharpouawa in Nuwakot district, approximately 26 km away from Kathmandu. It is estimated that the solid waste of the Kathmandu valley can be landfilled in this site for the next 50 years (Mishra and Kayastha, 1998). The construction of an access road to this site is in progress. Since the road passes through a mountainous area, the operation and maintenance cost of the road in monsoon season and the transfer cost of the solid waste may become a financial burden to the municipalities.
5. Impact on the environment and public health In a survey, 59% of the respondents in Nepal stated that they consider solid waste a major problem (ENPHO, 2001). Normally, this kind of survey data reflects the public knowledge and awareness of the environmental health aspect. Al-Yaqout et al. (2002) carried out a survey on the public perception on the landfilling and its public health aspect in Kuwait. The study revealed that less than 50% of the respondents were aware of the public health impact of the landfilling, and visual appearance of the landfill scored the lowest in importance. Environmental impacts of poor solid waste management lead to the deterioration of ground and surface water quality, as well as air and land pollution. The impact depends on the waste composition and disposal practices. The traditional landfill practice produces various landfill gases such as methane, carbon dioxide, carbon monoxide, nitrogen, hydrogen sulfide and ammonia. The percentage of green house gases (methane and carbon dioxide: 40–60%) is high (Tchobanoglous et al., 1993). Some of these gases have a pungent odour (ammonia and hydrogen sulfide) and are poison-
559
ous. If a proper collection or venting system is not provided, these hazardous fumes can create a health risk for the population near the landfill. In Nepal, the composition of the gas produced from the landfills and the health effects on the waste workers exposed to the landfill and the population nearby are unknown. An environmental study conducted by NESS in 1996 reported that the implementation and the operational phase of the Gokarna Landfill was not carried out properly as planned. This report indicated that infrastructure developed for landfilling such as landfill liners, leachate control, collection and treatment facility, gas control, collection and use facility, surface water drainage facility, compaction, final cover soil and the environmental monitoring facilities was not adequate. The same report indicated that inadequacy of aesthetic consideration in implementation, lack of public health and safety consideration, inadequate animal and bird control and poor maintenance were the major reasons that Gokarna Landfill poses a threat to public health. The characteristics of the leachate from the Gokarna Landfill are presented in Table 2. The report by NESS (1996) indicated that various water quality (ground and surface water) analyses were carried out by different organizations at different times to observe the contamination of water resources. The water quality analysis conducted by GTZ showed that there was no measurable contamination of ground and surface waters downstream of the disposal site either by inorganic, organic or heavy metals pollution (NESS, 1996). NESS (1996) conducted analysis of groundwater at seven locations and two spring water sources around the landfill site. It is very interesting that even with that poor management and operation of the landfill development, the water quality of the most of the wells were found to be unpolluted. Six out of the seven groundwater test results showed a high iron level (1.07–2.9 mg/L) and one spring source showed an iron level of 4.6 mg/L. It is not known whether the iron content was high in the groundwater itself. The lead content was slightly higher than the limit set by the WHO in one of the seven groundwater samples and in one of the two spring water sources; otherwise, water quality was found to be good (NESS, 1996). However, Khadka (1998) speculated that there was a high risk of groundwater contamination near the Gokarna Landfill area as the underlying soil is comprised of sand and silt with a low cation exchange capacity. This is supported by the fact that the solid waste was laid without liners at the bottom; soil cover was also very poor, aggravating percolation of the surface runoff through the landfill thereby increasing the quantity of leachate produced. Leachate collection and control and the protection against the erosion of the waste dumped were virtually non-existent in Bishnumati Landfill. The landfill was poorly developed and no consideration was taken to
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Table 2 Characteristics of leachate from the Gokarna Landfill and Bishnumati Landfill Parametersfl
Gokarna Landfill (NESS, 1996)
Bishnumati Landfill
(1) Mar. 1996
(2) Dec. 1988
(3) 1988
(4) 1988
Sharma et al. (1995)
PH Conductivity (lS/cm) Color (Chromacity Unit) Turbidity (NTU) TSS (mg/L) TDS (mg/L) Total alkalinity as CaCO3 (mg/L) Total acidity as alkali consumption (mg/L) Total hardness as CaCO3 (mg/L) Calcium (mg/L) Magnesium (mg/L) Chloride (mg/L) Phosphate (mg/L) Total phosphorus (mg/L) Ammonia-N (mg/L) Nitrite-N (mg/L) Nitrate-N (mg/L) Organic-N (mg/L) Sodium (mg/L) Potassium (mg/L) Lead (mg/L) Copper (mg/L) Nickel (mg/L) Chromium (mg/L) Zinc (mg/L) Cadmium (mg/L) Iron (mg/L) Manganese (mg/L) BOD (mg/L) COD (mg/L)
6.75 13,500 273 640 1144 30,036 8798 19.71 9500 2700 656.1 24,046 0.76 0.80 808.0 0.98 2.73 534 618.25 1625 0.32 0.07 0.55 0.38 0.26 0.03 323.11 39.74 3500 45,500
7.10 10,050 – – 2923a – – – – 512 166.4 845 3 – 343 CND CND – – 1110 0.10 0.1 3.7 0.6 0.31 0.3 30.7 5.4 – –
– 2090 – – – – – – – – – 190 – – – – – – 112 189 – – – – – – 2.6 – – –
7.6 10,255 – – – – – – – – – 4463 – – 485 – – – – – – – – – – – – – 5003 7148
7.53 8790 90 700 – – 4621 – 2130 455 242 1290 0.3 – 518 0.02 2.7 1239 953 1127 0.28 0.14 0.13 1.06 0.65 0.01 9.1 3.8 – 3205
Note: The data on the leachate at Gokarna Landfill were from different sources: (1) NESS; (2) Asian Institute of Technology (AIT); (3) Presenius; (4) DISWI. a Volatile solids.
safe-guard public health of the surrounding area (Sharma et al., 1995). The leachate was discharged to the River Bishnumati, causing contamination of the river water and this had an adverse impact on agricultural resources downstream. The Bagmati and Bishnumati rivers are of religious importance for Hindus in Nepal. Solid waste dumping on the banks is not the only source of pollution of these rivers. Poor wastewater management is the major reason for river pollution. Alternate measures should be considered instead of dumping the waste in the rivers.
6. Discussion Political instability in the country, especially after the restoration of democracy in 1990 contributed in some measure to the poor environmental management of solid waste. The successive governments after restoration of democracy were engaged in the intra and extra political disputes, paying less attention to infrastructure development and environmental management. There was little political commitment to resolve the crisis. Poor institu-
tional experience, lack of strong legislation and enforcement, and poor financial status of both government and the municipalities were the cumulative reasons for the poor solid waste management. Thapa (1998) suggested that the collection of a service fee, involvement of the private sector in waste management, environmental awareness building in the public and the enforcement of stringent environmental legislation were necessary for sustainable management of solid waste. Nepal needs to learn from the experiences of other countries in the practice of managing solid waste. Post (1999) suggested the involvement of the private sector with close monitoring by the government to manage the solid waste in Kumasi, Ghana. MexicoÕs experience in managing the municipal solid waste was presented by Buenrostro and Bocco (2003). The authors pointed out that inadequate resources of municipalities such as financial, technical and human infrastructure were the reasons behind the improper management of solid waste in Mexico. Technically, the composition of the solid waste is an important consideration in deciding on the type of disposal method to adopt for a particular community.
D. Pokhrel, T. Viraraghavan / Waste Management 25 (2005) 555–562
Metin et al. (2003) reported that about 50% of the waste generated in Turkey was of organic origin. The authors suggested a separate collection system for the recyclable solid waste. The recyclable solid waste consisted of onefourth of the total municipal solid waste. Mongkolnchaiarunya (2005) reported on a successful story of an incentive program ÔGarbage for EggÕ launched in Yala municipality, Thailand. A total of 66.8 tons of the recyclable waste was collected from the local area through this program. The composting of solid waste is one of the sustainable ways of managing it if a large fraction of the waste is organic in nature. Since more than 70% of the solid waste generated in Nepal is of organic origin, composting is one of the best ways to manage solid waste. Timilsina (2001) reported that 21% of KathmanduÕs waste is recyclable and 62% of the waste is compostable. Aerobic composting is gaining in importance worldwide as it has substantial benefits over traditional landfilling. Read et al. (2001) reported on the enormous advantage of aerobic landfills compared to conventional anaerobic landfilling. The authors concluded that the aerobic approach could be implemented in new as well as existing landfills to significantly reduce costs, leachate and green house gas production rate, and would rapidly stabilize the waste mass. Leachate recirculation in the landfill is an option to reduce the environmental impact of a landfill, increasing the microbial population inside the compost reactor or in the landfill and substantially reducing the waste mass. Aerobic biological pre-treatment of the MSW had been carried out in Germany since 1970 to decrease waste mass, increase landfill density, improve leachate quality and reduce the attraction to birds (Read et al., 2001). Aerobic landfilling had received considerable attention in Germany, Japan, USA, India and other parts of the world. Successful aerobic composting of the municipal solid waste in Bombay, India (capacity 300 tons/day processing capacity) was established in 1992 by a private company. The compost is being sold at a rate of Rs. 2 kg1. Similar composting plants were expected to be established in Banglore, Calcutta, Thane, Chandigarh, Gwalior, Solan and Delhi (Gupta et al., 1998). Nearly all the Indian cities dispose of their waste by simple dumping: only 8.6% practice composting whereas 89.8% use land dumping and 1.6% use other ways of disposal (Gupta et al., 1998). Hamer (2003) suggested composting as the best option to ensure public health and environmental safety in managing solid waste. The other means of treatment are often more expensive than landfilling. For example, 73% of the waste generated in Singapore are disposed of by incineration. The waste volume reduction by incineration was about 90%. However, the cost of incineration was about 6–7 times higher than the cost of landfill (Bai and Sutanto, 2002).
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7. Conclusions The following conclusions were drawn from this study: 1. The composition of the solid waste generated in Kathmandu and other municipalities in Nepal is dominated (70%) by organic material. Composting of the solid waste and using the compost as an organic fertilizer is a sustainable way of managing solid wastes in Nepal. 2. The source separation of the recyclable material such as metals and plastics by increasing awareness among the public is important to reduce the waste treatment cost. 3. Involvement of the private sector in waste management is required for sustainable management of solid waste in Nepal. The concept of public private partnership (PPP) may be suitable in order to develop public understanding of their investment in waste management. 4. Municipalities must enforce strict regulations to prevent illegal dumping of solid waste on riverbanks and in public places.
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