Solid waste management is a growing global challenge, with the increasing volume and complexity of waste posing significant risks to ecosystems and human health. An estimated 11.2 billion tonnes of solid waste is collected worldwide annually, with poor management contributing to air pollution, water contamination, and greenhouse gas emissions, particularly methane and carbon dioxide. In developing countries, inefficient collection and disposal methods further exacerbate environmental and health concerns (UN enviroment Program, n.d.).
Sri Lanka generates approximately 7,000 metric tonnes of solid waste daily, with the Western Province accounting for nearly 60% of total waste production. Each individual produces an average of 0.4 to 1 kg of waste per day, yet only 50% of the waste is collected, according to the Waste Management Authority and the Central Environmental Authority. Over the last two decades, the Sri Lankan government has attempted various waste management strategies, including sanitary landfills and waste-to-energy projects. However, the lack of a unified and coherent strategy has led to inconsistent policies and inefficient waste collection systems, resulting in severe environmental degradation and public health crises. Tragic incidents, such as the 2017 Meethotamulla garbage dump collapse, which killed 30 people and destroyed over 100 homes, highlight the urgency of improving waste management systems (EFL Admin, 2018). One of the most pressing issues in waste management is the inefficiency in waste collection and transportation. In Sri Lanka, waste collection relies primarily on door-to-door collection, communal storage bins, kerbside collection, and block collection systems (Basnayake & Visvanathan, 2013).
Moreover, seven waste management steps were identified to streamline the management and handling of MSW in the Western Province. They are namely; the management of waste at source, proper collection/acceptance of waste from the generating point, cleaning of streets and public places, providing of adequate infrastructure facilities, improved system of waste transportation, use of collected waste as a ‘‘resource’’ and the providing of proper final disposal facilities (Basnayake & Visvanathan, 2013). The collection, disposal, and recycling of solid waste pose significant challenges in many nations, particularly in developing countries. In Sri Lanka, especially in Colombo, ineffective waste management has led to unclean and unhealthy urban environments. The Colombo Municipal Council bears the primary responsibility for maintaining the city’s cleanliness (J, 1987).
However, logistical challenges, lack of infrastructure, and ineffective transportation routes contribute to inefficient waste disposal, leading to increased operational costs and environmental damage. In many developing countries, unplanned waste collection routes result in excess fuel consumption, traffic congestion, and higher CO₂ emissions. Thus, integrating route optimization into waste collection processes is crucial for achieving a more sustainable and environmentally friendly waste management system
Route optimization involves applying mathematical modelling techniques such as Vehicle Routing Problem (VRP) algorithms, Dijkstra's Algorithm, and Mixed-Integer Linear Programming (MILP) to identify the most efficient waste collection routes. By utilizing graph theory and shortest path algorithms, these models minimize travel distances, reduce fuel consumption, and optimize fleet capacity. Additionally, metaheuristic approaches like Genetic Algorithms (GA) and Ant Colony Optimization (ACO) help solve large-scale, complex waste collection problems while balancing cost-effectiveness and sustainability
Study focuses on optimizing waste collection and transportation routes in Kuppiyawatta East, through statistical analysis and mathematical modelling. Kuppiyawatta East, located in the Thimbirigasyaya Divisional Secretariat of Colombo District, is a densely populated urban area surrounded by Maligawatta East, Maligawatta West, Maligakanda, Borella North, Wanathamulla, and Kuppiyawatta West. It houses key institutions such as St. John’s College, Nalanda College, and Ananda College (Kuppiyawatta East Grama Niladhari Division, n.d.) and faces significant waste management challenges due to its high population density and urban congestion (Wikipedia Contributors, 2024)
This study aligns with Sustainable Development Goal (SDG) 13: Climate Action, In the context of SDG 13 and combating climate change, the term defined in the United Nations Framework Convention on Climate Change (UNFCCC) (1992), as the 'change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate Key Terms SDG 13: Take urgent action to combat climate change and its impact(A LEGAL GUIDE, n.d.).
Waste management and climate action are deeply interconnected, playing a crucial role in achieving SDG 13, Target 13.5, which emphasizes promoting mechanisms for raising capacity for effective climate change related planning and management. Optimizing waste collection routes through mathematical modelling enhances efficiency, reduces fuel consumption, and lowers CO₂ and methane emissions. Strengthening waste management systems with data-driven strategies supports climate resilience, minimizes environmental impact, and contributes to a sustainable future