With soaring overpopulation and increased urbanisation in the cities across the country, there arises the essential problem of waste disposal. A pile of garbage bags sitting outside gates and doorsteps is a common sight in most residential areas of Colombo. At times, the bags break open and the food waste spills onto the pavement, carrying with it the stench of rotting food. Residents of rural areas face another problem. Trash from the cities are transported and dumped at their doorstep. At times, illegal garbage dumps near wildlife sanctuaries act as death traps for animals feeding on them, including elephants. Over time, garbage has become an issue every major city in the island grapples with. Post Meethotamulla , Sri Lanka is finally moving gradually towards long term sustainable solutions for waste management, with sanitary landfills, and waste to energy projects, in the offing.
Speaking to Sunday Observer, Deputy Director General, Waste Management of the Central Environment Authority (CEA), Engineer Upali Indrarathna said the main responsibility of waste management is vested with local authorities. Under Environment Act 47 of 1980, CEA has powers to regulate the system and enforce law. He said, approximately 8000 metric tonnes of waste is generated per day, of which 45 to 50 % is biodegradable material which can be composted. 15 to 20 % is recyclable waste, of which, only six to seven per cent is currently recycled, the balance goes to municipal solid waste. The other 30 to 40 % is landfill waste, which should be converted into a fuel via incineration. This can be either Refuse Derived Fuel (RDF) or Solid Recovered Fuel (SRF). “However, currently we have no such facility and this waste goes to open dumps, which is illegal. Sanitary landfill is the approved method of disposal for mixed waste,” he said. Sanitary landfills are where waste is isolated from the environment by layering waste and soil in a dug up in the ground. Then, waste is allowed to decompose. The surface of the dug up is lined with plastic and clay prior to laying waste to prevent contamination.
Indrarathna further said if bio degradable waste can be segregated and separated, half the problem is over. “151 plants were provided to local government authorities for such purposes and eight plastic recycling centres capable of collecting, washing and pelletising were provided to Municipal Councils in Matara, Kurunegala, Kandy, Nuwara Eliya,Badulla, Anuradhapura, Jaffna and Balangoda, but they have performed poorly so far,” he said. Further, nine Kawashima plants, which are, mechanised composting plants, with the capacity to dispose 50 metric tonnes of waste per day, will be handed over to the nine Provincial Councils by the Ministry of Local Governments and Provincial Councils.
Currently, long term sustainable projects are in operation when it comes to management of organic waste and non degradable substances in Metro Colombo, but sustainable solutions for mixed waste is still in the pipeline, said Ministry of Megapolis and Western Development, Solid Waste Management Project, Project Director, Jayavilal Fernando. Accordingly, the organic waste, including food waste from Colombo Municipal Council, Kelaniya, Kaduwela, Wattala, Kolonnawa areas are sent to the Kerawalapitiya compost plant. Part of the non – degradable material including polythene and plastic is collected from homes and sent to the compost plant, where it is separated and sent to recycle plants to create recycled products, while some of the non-degradable material is collected by private parties. “However, the issue is the 250 to 300 metric tonnes of mixed waste collected per day, which is currently being deposited in a temporary landfill in Muthurajawela, which is not sustainable in the long term. Long term solutions to mixed waste include waste to energy projects and sanitary landfills,” he said.
Generating energy from waste
Waste to energy projects involve burning of mixed waste to generate power. Fernando said two such plants will start as private public partnerships in Kerawalapitiya and Karadiyana areas. “Waste will be supplied by the waste management authority and the private party will operate the plant. The Government will purchase the power generated. The project is approved with a costly cleaning system to clean the Carbon monoxides, Carbon dioxides, Oxides of Nitrogen and Sulfur Oxides emitted during the power generation process, he said. Further, it will take approximately two and a half years for the plant to begin operations. It is estimated to utilise 1000 metric tonnes of waste per day for the process of power generation.
A sanitary landfill is currently operated in Dompe by the CEA, where waste from Dompe, Colombo Municipal Council (CMC), certain other local authorities and industries is currently being sent. The capacity of this sanitary landfill is 90 tonnes of solid waste per day. “We are planning to develop 32 to 35 landfill sites in Sri Lanka. Currently, four sanitary landfill projects in Anuradapura, Galle, Polonnaruwa and Jaffna areas are in the tender stage, which will be constructed with financial support from the Korean Government. Approval has also been obtained to build a sanitary landfill in Pethiyakanda, Attanagalla to accommodate reduced waste from Gampaha district and we are awaiting financial support,” he said. Further, two sanitary landfills in Rathnapura and Monaragala areas are awaiting Treasury approval and land is being identified for sanitary landfill in Ruwanwella. Meanwhile, Japan International Cooperation Agency (JICA) will be carrying out a sanitary landfill project in Kataragama, to hold waste from the Kataragama Pradeshiya Sabha.
Also, the main project is the sanitary landfill being built in Aruwakkaru, Puttalam by the Ministry of Megapolis, which is currently in the initial stages. This will be a final disposal site for mixed waste in Metro Colombo, Vanathavilluwa and Puttalam areas. “The landfill can accommodate about 1200 metric tonnes of waste per day. Initially, mixed waste will be used to fill the site. However, degradable waste should be composted rather than being sent to landfill. Therefore, we are hoping to gradually use non degradable and non recyclable material for the landfill,” Fernando said.
He added that designing of the landfill is completed at the moment and the project will start operations at the end of next year. “Once the landfill is complete and capping is done, it can be converted into a dry zone forest,” he said. He added that landfills can also be converted into profit earning parks once the capping is done.
He further said that it was difficult to operate a landfill gas plant for commercial purpose in these sanitary landfills, since large amounts of waste is needed to turn a turbine to generate landfill gas, but Sri Lanka does not produce these amounts of waste. Landfill gas is a mix of gases consisting of mainly methane, created as a result of micro-organism activity within a landfill. In some countries, landfill gas is utilised for electricity generation.
Hazardous waste
Eng. Indrarathna said CEA was also responsible for issuing hazardous waste management license for disposal systems developed for industry level waste disposal. Fernando said some industrial waste is currently utilised by a cement company to create renewable energy in their cement manufacturing process. The company charges the respective industries for using their waste.
When it comes to hospital waste, there is general waste which is disposed with Municipal waste, but clinical waste has to be treated separately by incineration and converted to a type of solid waste prior to disposing, said Indrarathna. “This can be done via destroying the germs at high temperatures by using autoclave or hydroclave technologies,” he said.
Electronic waste such as washing machines, refrigerators, hybrid car batteries, laptops etc, have to be treated in a separate manner.
“A hazardous waste management license is needed to transport, treat or dispose e waste. There is no treatment or disposal of e waste available in Sri Lanka other than for fluorescent bulbs, which are treated in Horana,” Indrarathna said. Accordingly, bulk of the e waste is exported with the Basel approval from importer, exporter and the transporter, he said.
Waste management for apartment dwellers
Speaking of microlevel waste management issues faced by households, especially in the capital where a notable fraction of the population lives in apartments, Fernando said there were two pilot projects in operation, for waste disposal in apartments. One project involves 3R (reduce, reuse and recycle) system of waste management, which involves further segregation of waste and separation into high density and low density material. “Currently, this pilot project is in operation in Urban Development Authority ( UDA) apartments and schools such as Vishaka Vidyalaya and Isipathana College, Colombo,” Fernando said.
The other pilot scale project is the use of Takakura method to compost, where a microbial culture is used to increase the decaying speed. “This way, people can make compost even on their balconies.However, this is still at pilot level.This method is being carried out in UDA apartments and Royal Park Apartments in Rajagiriya,” he said.
From 2016, Singapore has been a country that disposes 8,559 tonnes of waste per day. It has a waste management system which begins at micro levels, from the homes and businesses, where recyclables are sorted and retrieved prior to the collection of solid waste. The solid waste is incinerated at various waste to energy plants, to produce steam that runs turbines to generate electricity. Ash from the process is then transferred to Semakau Landfill, with other non- incinerable waste. Semakau Landfill remains Singapore’s only sanitary landfill facility. Japan has a system where reuse, recycling and use of waste material via heat recovery is encouraged. Further, they have developed a system where waste undergoes intermediary treatment via incineration and other methods, prior to disposing in sanitary landfills, to address the limited landmass available for landfill sites.
According to a World Bank study, by 2025, waste produced in cities around the world can fill 3100 mile long rubbish trucks per day. An exponential growth has been predicted for the world garbage crisis, with the increase in urbanisation. Thus, there is the need to be ready with a sustainable waste management system to avoid being drowned in trash.
Further, the National Task Force for Management of Waste is there to hear any garbage related grievances in the Colombo District, which will be directed to the engineer in charge of the area, who will then take action.
Task Force can be reached via 0113301445/ 0115993755.