Household waste collection : factors and variations

Sammanfattning: Ambitious household waste recycling programs have been introduced in Sweden and several other countries during recent decades. Many different waste- sorting and collection schemes have been developed, but the evaluation and comparison of the results is made difficult by the lack of comparable data. The aim of the research presented in this thesis was to answer the following questions: How can household waste flows be described and monitored? Which factors affect the collection results? and, What is a useful basis for the evaluation of collection systems? Waste flow analysis and waste component classification were performed in a number of Swedish municipalities, revealing a wide variation in the amount of waste per capita. Eleven site-specific variables were investigated and multivariate data analysis was performed. The study was carried out on three levels: 1) household waste as the material in itself, classified into physical components, 2) the householders and their handling of waste, in terms of average amounts of different waste categories and recyclables per capita, and 3) the municipalities, as the authority responsible for household waste management, where local conditions influence waste generation and pathways. A significant finding was that property-close collection of dry recyclables led to increased collection of sorted metal, plastic, and paper packaging. Weight-based billing, i.e. when waste collection is charged per kilogram of waste collected, showed divergent effects, which are investigated and discussed. Monitoring methods are suggested regarding the waste flow from households. A step-by-step method for evaluation and comparisons of collection systems was outlined, including a set of indicators. Sixteen sources of error in official waste statistics were identified and the results of the studies emphasize the importance of reliable waste generation and composition data to underpin waste management policies.