Illegal Industrial Waste Dumping on Iki Islands - December 1996

Illegal Industrial Waste Dumping on Iki Islands - December 1996

Off the coast of Marugame City, Kagawa Prefecture, approximately 500,000 tons of industrial waste have accumulated on Iki Island due to illegal dumping that began in the 1950s. This waste contains diverse hazardous substances, including construction debris (30%), plastics (20%), waste oil (10%), and asbestos (5%), posing serious environmental risks. The accumulated waste reaches a maximum height of 12 meters and covers over 10% of the island's total area.

Responding to strong demands from residents, Kagawa Prefecture held a residents' assembly in 1996 and adopted a disposal plan combining on-site incineration with off-island removal. This plan involves processing 60% of the total waste in high-temperature incinerators and transporting the remaining 40% to a final disposal site. The processing period is estimated at 10 years, with total costs projected at 1.6 billion yen.

Transportation would use dedicated ships capable of handling 20 tons per day, with approximately 12,000 trips planned over the decade. After processing, about 500,000 cubic meters of land would become reclaimable, and plans were outlined to promote afforestation across the entire island. The breakdown of processing costs included 1 billion yen for incineration, 400 million yen for transportation, and 200 million yen for environmental restoration.

The background to the illegal dumping began with the rapid increase in construction waste during Japan's period of high economic growth in the 1970s. At that time, waste disposal companies, seeking to cut costs of ¥5,000 to ¥10,000 per ton, are said to have dumped waste on the islands without permission. As a result, the dumped volume exceeded 20,000 tons annually, accumulating over 500,000 tons over approximately 25 years.

Concerns for residents' health include foul odors from the waste, asbestos dispersion, and groundwater contamination. In response, the Environmental Agency conducted air quality tests and reported detecting harmful substances exceeding standard levels. Prompt countermeasures are required, and this disposal plan represents the first step toward resolving the issue. Date inferred from file name: December 1996