Illegal Dumping of Ikujima Industrial Waste - December 1996

Illegal Dumping of Ikujima Industrial Waste - December 1996

On Ikushima Island, off the coast of Marugame City, Kagawa Prefecture, about 500,000 tons of industrial waste have accumulated due to illegal dumping that began in the 1950s. This waste contains a wide variety of hazardous materials, including construction waste (30%), plastics (20%), waste oil (10%), and asbestos (5%), posing a serious risk to the environment. The maximum height of the deposit reaches 12 meters and covers more than 10% of the entire island.

In response to strong requests from residents, Kagawa Prefecture held a residents' convention in 1996 and adopted a treatment plan that combines on-site incineration and removal from the island. Under this plan, 60% of the total waste would be treated in a high-temperature incinerator, and the remaining 40% would be transported to a final disposal site. The treatment period is estimated to be 10 years, and the total cost is 1.6 billion yen.

A dedicated 20-ton per day vessel will be used to transport the waste, with approximately 12,000 trips planned over the next 10 years. After treatment, approximately 500,000 cubic meters of land will be available for reclamation, and plans have been presented for afforestation throughout the island. The breakdown of disposal costs is as follows: 1 billion yen for incineration, 400 million yen for transportation, and 200 million yen for environmental restoration.

The background of illegal dumping began with the rapid increase in construction waste during the period of high economic growth in the 1970s. At that time, waste disposal companies dumped waste onto several islands without a permit in order to reduce costs, which ranged from 5,000 to 10,000 yen per ton. As a result, the amount of dumping exceeded 20,000 tons per year, accumulating to more than 500,000 tons in about 25 years.

There are concerns about the health hazards to residents, including odors from the waste, scattering of asbestos, and contamination of underground water. In response, the Environmental Agency conducted an air quality inspection and reported that toxic substances exceeding standard values were detected. Prompt countermeasures are required, and this treatment plan is the first step toward solving the problem.

Estimated date based on file name: December 1996