Waste Management and Climate Neutral Cities – In Conversation with Prof. Ajith de Alwis
Compiled by Seth Ganepola
23 September 2019

This article is based on an interview with Prof. Ajith de Alwis from the University of Moratuwa. He is also the Project Director of the Coordinating Secretariat for Science, Technology and Innovation (COSTI) Sri Lanka which is a Division of  theMinistry of Science Technology and Research.

Prof. Ajith De Alwis is the Project Director of the Coordinating Secretariat for Science, Technology and Innovation (COSTI) Sri Lanka

COSTI is mainly focused on integrating Science and Technology into the decision-making process and pushing the Science and Innovation agenda of the country. It has two primary intentions:

  1. Emphasizing the sentiments of Munidasa Kumaratunga who stressed the importance of being creative across all sectors for realizing growth of a country.

  2. Converting research into rupees.


According to the Global Climate Risk Index 2019, published by Germanwatch, Sri Lanka stands to be the second most vulnerable country among the 10 most climate change affected countries.

While Sri Lanka’s position according to this analysis could be called into question, the fact that the country’s resilience to disasters is low is undeniable. Upon further observation it can be noted that this risk assessment has been done with respect to droughts, floods and landslides, and in Sri Lanka rains and floods cause landslides because of bad land management and soil management practices. As such, although Sri Lanka is not a country that should be in such a precarious position or one that should be facing such major climate risks, by not doing things correctly or efficiently we have put ourselves into a vulnerable position in which our resilience is low. The wasteful practices we adopt in relation to water are the perfect example.

Similarly, although another survey which ranks Sri Lanka fifth in the list of countries that release plastic and polythene waste to the ocean is based on inaccurate data, a visit to our coastline strewn with garbage would cause anyone to believe that survey ranking to be true. Therefore, while on one hand Sri Lanka needs to fight misinformation, on the other hand it needs to start doing the right thing in relation to dealing with climate change.

Let’s unpack this further by looking at how the Sri Lankan Waste Management system works.


Where does all the garbage go?

A significant amount of waste is produced daily, particularly in urban areas. Much of the waste generated in urban areas is transported to different garbage dumps and landfills. Sri Lanka now has around 320+ garbage dumps which has gone up from 260 garbage dumps during the Meethotamulla incident. Another significantly large portion of waste is to be taken by the emerging Waste-to-Energy Plants (This is for the Western Province). This discussion focuses on two of these Waste-to-Energy Plants to be located in Muthurajawela and Karadiyana, and it is extremely important to understand the differences between them.  Both these plants are now under construction.


The Aruwakkulu Landfill

The Colombo Municipal Council transports its waste to a landfill in Aruwakkulu.

Thus, what is done right now is that we dispose waste matter in a technically designed landfill in a weak geological formation and also perhaps in a sensitive environment. However, dumping garbage in landfills is an outdated practice which would have suited the 20th century very well but the 21st century frowns upon the disposal of garbage in landfills because of the Methane emission that in turn affects climate change. Today sending organic waste to landfills is expressly banned or getting phased out fast for this reason, even though landfill gas capture is available.  Even though we carry out landfill gas burning it is a complete waste of resources considering the amount of fuel burnt moving this waste over a hundred kilometres away. In the case of the Aruwakkalu landfill for instance, a truck has to travel close to 170km from Colombo to transport the garbage there, costing millions a day and up to billions a year.


The Muthurajawela Waste-to-Energy Plant

The Muthurajawela Waste Management System comprises of an incineration plant with the capacity to process 700 metric tons of waste generated from the Colombo Municipal Council daily. This Waste Treatment Plant produces an estimate of 10 MW worth of electricity to the national grid once commissioned, converting waste generated in Colombo and Gampaha into energy. Follow the link to read the recent story Unlocked published on this plant

What are the issues associated with the Muthurajawela Waste Treatment Plant?

According to Prof. Ajith de Alwis, the incinerators in Muthurajawela are burning waste that is not easily combustible. The waste that is burnt in Muthurajawela has a high level of moisture which means that the amount of electricity produced is rather limited. Even though the visible waste disappears when it is burnt, it doesn’t mean that the risk is over. What happens is that by burning, the solid waste is converted into different gases. This does not end pollution. In fact, if this air is not cleaned, it increases the risk of pollution since the mass burning of this waste encourages an indirect increment in air pollution. The chemicals that are used to purify this polluted air creates multiple effluents, which are hazardous wastes, and again requires secure land filling. Secure land filling is not what is available at Aruwakkalu.  Ultimately when the costs of chemicals, air pollution mitigation, transportation are all added up, this method proves to be extremely expensive.  That is why thermal incineration systems are also finding their way out from solid waste management.


The Karadiyana Waste-to-Energy Plant

The waste treatment mechanisms used in Muthurajawela and Karadiyana are two very different technologies. The Karadiyana plant is a Bio-waste to Bio-energy plant. There is also a thermal incineration plant for combustible waste as a segregated stream. Karadiyana mainly treats the waste using Anaerobic Digestion. Anaerobic Digestion is on the top of the waste management pyramid. This, according to Prof. Ajith de Alwis, is the most feasible waste management system right now. The high level of moisture in the waste in these plants is not really a matter of concern in this system. In fact, it is rather welcome! It produces bio gas and does not require further air purification from an air pollution aspect. If biogas is purified then one can upgrade it to SNG (Synthetic Natural Gas which has a high value). In that sense the Karadiyana Waste-to-Energy Plant is much more practical, cost effective and eco-friendly. Unlike hazardous effluents from a thermal incineration plant, a biogas plant would deliver, in addition to electricity, solid and liquid soil amendments. Instead of additional expenditure, these are revenue earners.



The Karadiyana waste to energy project recommenced in 2019 following some set backs – Excerpt of an article published in the Daily Mirror on 3 June 2019


Is the Karadiyana Waste-to-Energy Plant the best option?

Although the Karadiyana plant is a much better alternative to the Muthurajawela one, it is difficult to completely agree with its entire operating model. The first phase of waste management in Karadiyana is the most feasible technology that can be used in waste management. However, in the business model of the waste management plant, the viability comes mainly from selling electricity to the Ceylon Electricity Board. For this, the plant has to produce electricity as much as possible by burning plastic. Therefore, even at Karadiyana there is an incineration plant. The higher the plastics burnt, the higher the electricity. Moreover, this final process goes against the National Policy of 3R (Reduce, Reuse and Recycle). It must be indicated that as the Karadiyana incineration plant uses segregated combustible waste, that would not face the moisture issue and the electricity generation is optimal. However, that particular plant too will face the air pollution control issue and associated costs. With recycling and better resource conservation the overall plant has the ability to run in decoupled mode and that is an advantage.


What are the flaws in the current Waste Management system in the country?

  1. Giving prominence to short term solutions: We are very reactive and even in a reactive phase we are still looking at short-term solutions.

  2. Political issues and major inefficiencies in decision making. After many years discussing this issue we have shown our weakness in not valuing knowledge.

  3. Misinterpretation of goals: The ultimate goal should not be to keep the city clean, but to properly dispose the waste produced in the urban areas and benefit from the process as well.

  4. Lack of investment in the Environmental Management Industry: Waste Management is an industry. Sri Lankans expect someone else to build up this industry by investing in it.

  5. Lack of priority: Waste Management is not prioritised in city planning in Sri Lanka. Finding space is fraught with extreme difficulty.

  6. Cost of technology: Even a simple solution to a waste stream like moving away from CFL bulbs to LED bulbs for instance, is quite costly. Again, we tend to settle on low level inefficient technologies and then blame their poor performance. A good example of this is in composting.

  7. Lack of focus on attitudinal change: One of the major problems in the system is that the ministries and local councils focus on solving the current problems in their own way without pushing to change the attitudes of people to prevent future issues from arising. Again, all awareness has led to nowhere. This has been a topic which so many have been trained on, exposed to and discussed.  The net outcome except in few places is difficult to accept. Professionals however, have been hampered by bad politics and that must be acknowledged.

How can Waste Management in Sri Lanka be improved?

  1. Polluter-Pays Principle: this is the practice that says that the producers of waste that create pollution should bear the costs of managing it to prevent damage to human health or the environment.

  2. Extended Producer Responsibility: the producer will be responsible for the subsequent packaging waste and will have to take back the packaging waste for the production process.

  3. Circular Economic principles to be adopted. Waste is not looked at with the intention to dispose but to push back to processes.   Giving value to all resources and waste also is considered a resource.   The technologies to be selected and used become those which extract value rather than neutralise some for disposal.

  4. Zero-Produce Waste Management Plan: This does not mean that people do not produce waste, but rather it means that the waste that is produced does not remain as waste. Within the zero-produce waste management plan we must look at what is recyclable, what is reusable, what is reducible, and must push for quantitative data and see how much waste is generated by a person within a given region. In the urban areas it is said that 1.1kg or 0.74kg of waste per person is produced but when we move away from the urban areas to rural areas it reduces to 0.4 kg per person. We need to look at whether we can get the urban averages down to 0.5kg per person as well.

  5. Blue Green Economy: Environment-friendly approaches, replacement (plastics being replaced by biodegradables), bio gas systems, compost systems, recycling infrastructures need to be put in place. Once this is done, all possible waste streams (e.g. e-waste) need to be identified and solutions for each adopted.

  6. A Recyclers’ Industrial Estate: The proposal to create an Industrial Estate specifically allocated for recyclers.

  7. More private sector initiatives: glass companies, paper companies engaging in waste management (e.g. National Recyclers’ Association)

  8. Civic Responsibility: Everyone in society has to be responsible for the waste they generate.



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