## (4) The Heisei period (from 1989 to the present)

## A Amendment of the Waste Management Law and related efforts

The Japanese economy continued to grow, even after the high-growth period, creating a society with a high degree of material affluence. On the other hand, the country underwent social changes that led to the increased adoption of a lifestyle based on mass consumption and the throwaway principle. These changes resulted in an increase in the amount and the diversity of waste and made it harder to dispose waste appropriately. These developments have led to several phenomena and incidents such as municipal solid waste in the Kanto region being carried to the distant Tohoku region for disposal because of lack of incinerating facilities and the difficulty of securing final disposal sites; a large amount of industrial waste, primarily shredder dust, being illegally dumped in Teshima, Kagawa Prefecture; and a large amount of industrial waste, primarily waste oil, being illegally dumped in an abandoned mine in Fukushima Prefecture.

Since the beginning of the Heisei era, Japan has improved its framework for responsible waste disposal by amending the Waste Management Law and introducing a range of other initiatives to cope with a situation in which the waste disposal issue needs to be addressed not only as an environmental conservation problem but also as the more fundamental problem of how to deal with the wastes that are produced each and every day.

In order to become a member of the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal, Japan amended the Waste Management Law in 1992, in addition to enacting the Law for the Control of Export, Import and Others of Specified Hazardous Wastes and Other Wastes. This amended law stipulated that, in principle, all wastes should be disposed of within Japan, and imposed the necessary regulations on waste imports and exports (e.g., the introduction of an export confirmation system and an import permit system). Rules on the international movement of wastes were also established pursuant to this law.

There were other developments concerning measures to be taken against domestic hazardous substances as well. One of them concerned batteries containing mercury. In 1983, the Kurashi no Techo (A Note of the Life) magazine pointed out the risk of environmental pollution from the mercury contained in waste batteries. In the same year, the Tokyo Metropolitan Research Institute for

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# The semi-aerobic landfill structure (the Fukuoka method)

One of the landfill systems now used for final disposal sites is the semi-aerobic landfill structure (the Fukuoka method), which was first proposed in the second half of the Showa 40s (1970-1974) by Fukuoka University and the Fukuoka City Government. Because of its ease of construction and maintenance and its ability to quickly stabilize waste and improve the quality of the leachate, this landfill structure was adopted by the former Ministry of Welfare as the national standard and has been used by many municipal governments when constructing their landfill sites.

This structure uses large-diameter leachate collection and drainage pipes installed at the bottom of the landfill site in order to drain out the leachate and allow outside air to naturally flow into the inner landfill through these pipes via convection induced by the heat of waste decomposition. This design increases the decomposition capacity of the aerobic bacteria present and thereby improves the quality of the leachate. The ease of construction and maintenance is another advantage of this method, and there is no need to mechanically pump air into the landfill.

Since the semi-aerobic landfill structure allows cheaper construction and faster waste stabilization than the anaerobic landfill system promoted in the West, and since it can even restrict methane generation, it has recently attracted the attention of many developing countries as a sustainable technology and a suitable technology with which to help prevent global warming.

Conceptual image of the semi-aerobic landfill structure