Giljong Oh*, Toshihiko Matsuto* and Nobutoshi Tanaka*

* Department of Environmental and Sanitary Engineering Faculty of Engineering, Hokkaido University

+ Correspondence should be addressed to Toshihiko Matsuto:
(Kita 13 Nishi 8, Kita-ku, Sapporo 060 Japan)

Abstract

Accurate information on the quantity of waste is crucially important for waste management planning and operation. This study investigates how the quantity of household wastes varies depending on municipal government-mandated source separation categories. Two hundred cities in Japan were surveyed by questionaire. In spite of similar general classification systems for wastes (combustible, noncombustible and bulky) and recyclable materials, the quantity of household wastes differred significantly. By further investigation of the cities which had a notable difference in quantities of the wastes produced, two types of factors were determined: First, depending on the city the items included in the general waste separation categories varied. Second, the reduction of waste through recycling, disposal of kitchen waste by composting and by incineration at source reduced waste quantities. Two estimation models were made using the above factors and based on the statistical value and composition of household wastes. The level of accuracy in the models' were satisfactory and the reasons of error were explainable.

Key words: household waste, waste classification method, factor analysis, estimation model for waste quantity