waste, as before, assigned the responsibility for the dis-

posal of industrial waste to waste-generating businesses,

based on the Polluter Pays Principle.

With respect to the disposal of hazardous industrial waste, particularly strict standards were imposed on the final disposal of sludge and slag containing mercury, cadmium and other harmful substances following the entry into effect of the Waste Management Law in 1971, aimed at safeguarding people’s health.

Disposal facilities were also enhanced, following the institution of the Waste Management Law. On the other hand, negative effects of economic growth surfaced in connection with various waste disposal issues. One of these was the so-called Tokyo Waste War, a waste disposal dispute that started in 1971 between a municipal government and local residents over waste disposal. This became an issue of serious public concern. In those days, since the final disposal site within metropolitan Tokyo only had a limited incineration capacity, some domestic kitchen garbage was carried to a final disposal site in Koto Ward. Meanwhile, while Suginami Ward had a plan to build new incineration facilities in order to reduce the volume of waste, it could not implement this plan because of community objections against the construction project. The Suginami Ward Government had no other choice but to continue to carry waste to the final disposal site in Koto Ward. The Koto Ward Government, which regarded this act as forcing it to accept unwanted waste, began refusing to accept waste from Suginami Ward and this issue then developed into a serious public dispute. It is safe to say that this incident was the very first formative experience from which Japan leaned valuable lessons on how to select a site for waste disposal facilities and how to cope with local residents opposing the project.

After overcoming the first and second oil crises, Japan achieved a level of economic growth driven by many technological innovations, leading to the production and consumption of a wide variety of products. This also brought about changes in the composition of urban waste and created concerns over the emission of hydrogen chloride and other hazardous substances from incinerators, an issue that attracted attention as an emerging environmental problem. This was the starting point for Japan's efforts to ensure that waste incineration facilities had adequate environmental conservation capability, including measures against dioxins. To address the problem of night soil disposal, an advanced system for sanitary night soil disposal was established for traditional Japanese vault toilets, while sewage systems and Johkasoh were made widely available in order to meet the needs of flush toilets. In particular, as a result of technological advances, new Johkasoh were developed which were small enough to be installed in homes yet still had the same capability for high-quality treatment as public sewage systems. These tanks are now widely used.

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## I ntroduction of sorted waste collection (Hiroshima City)

In the postwar high economic growth period, Hiroshima City experienced a sudden increase in waste generation, as did many other cities throughout Japan. In Hiroshima City, kitchen garbage, categorized as “Hiroshima garbage”, was once used for fertilizing farmland in islands and other rural areas of the city. However, demand fell as chemical fertilizers came into general use. The existing waste disposal system was abolished in 1960. With no other place to go, most of the waste in the city was disposed of in landfills in the Showa 30s to 40s (1955-1974), but the city government increasingly found it more and more difficult to secure enough landfill sites. At Hesaka Junior High School, which was built on a former landfill site, there was even an incident in which methane erupted from the school yard.

In response, the Hiroshima City Government declared a state of waste disposal emergency in 1975 and urged the public to consider the waste disposal issue as their own problem. In an effort to reduce waste generation, in the following year (1976) the city introduced the sorted collection of waste for the first time in Japan. In this collection system, everyone was required to separate their own garbage into five categories: (i) combustible waste, (ii) non-combustible waste, (iii) recyclable waste, (iv) large-sized waste, and (v) hazardous waste. Although people were confused at the beginning, the new collection system gradually became established and has since come to be widely known throughout Japan as “the Hiroshima system”. This has now become a landmark in the history of waste disposal and a pioneering example demonstrating that even a big city like Hiroshima can operate a sorted waste collection system by gaining the understanding and support of its citizens.