Design effective waste management system
Shashi Bahadur Thapa
Air, water and land pollution by gaseous, liquid and solid wastes have evoked a great deal of concern in Kathmandu, especially in the five municipalities — Kathmandu Metropolitan City, Lalitpur Sub-metropolitan City, Madhyapur Thimi, Bhaktapur and Kirtipur municipality. Improved and sustainable solid waste management practices on an integrated basis are, therefore, the urgent need to provide and maintain better environment and hygienic living conditions.
Rapid urbanisation and commercialisation have chan-ged social status of waste collection, processing and disposal in the five municipalities, whereas the number of health conscious people is rising. Moreover, increasing pressures on land resources, materials and energy from the increasing population have co-mbined to make waste management a complex problem at local and national levels.
Solid waste from houses, street refuse, dead animals, construction wastes, hospital wastes and industrial wastes find their way to the municipal collection system. It is interesting to note that 50-70 per cent of the total solid waste collected is street refuse. A good knowledge of physical and chemical characteristics of solid waste is very essential for selecting the appropriate systems for collection, recycling and final disposal.
The generation of the solid waste in terms of per capita varies from individual to individual, area to area and country to country. Research shows that average generation of solid waste per capita per day is 325 gram/day in the five municipalities of Kathmandu. There is no standardised private temporary storage system such as dustbins. Kathmandu and Lalitpur have a system of public containers, which are located in different areas and the remaining three municipalities collect wastes from the roadside. The frequency of collection is also very low. At present, the Kathmandu and Lalitpur municipalities drop the waste into Bagmati river. The total cost of providing solid waste collection, transportation and disposal is mere 35 to 40 per cent of the total municipal operation budget.
The law of conservation and waste management implies only two possibilities in the case of Kathmandu: either recycle the waste or account for the dissipated loss. The more materials are recycled, the less will be dissipated into the environment. Resource recovery should be given a high priority. The municipal authorities should provide facilities and opportunities regarding exchange of waste with cash depots or services at community or ward level. To do this, it would be more efficient if institutionalisation of resource recovery mechanisms were to be introduced along with Deposit Refund System (DRS).
The chemical characteristics of solid waste in five municipalities of the Kathmandu Valley suggest that it is worthwhile to adopt biogas cum composting as an alternative method of solid waste disposal rather than land-filling. For the valley conditions, the use of biogas as energy source not only substitutes oil and wood, it also reduces import and transportation of fuel. Municipal bodies, NGOs, CBOs and stakeholders must be motivated to handle solid waste properly. The landfill site at Okharpauwa is apt for disposal of solid waste albeit under proper surveillance.
The need of the hour is to develop a cost-effective system of solid waste disposal. Any successful solid waste management control system is dependant on having field control and proper implementation, which requires the establishment of an integrated appropriate infrastructure, search for an innovative local system with appropriate technologies to suit the conditions of Kathmandu.