Tokyo, Jul 9 (IANS): As search efforts continued on Friday for 21 missing people following a large mudslide that hit a spa resort town in Japan last week, experts and local authorities suspect that improper accumulation of soil might have led to the deadly accident.
According to local authorities, a real estate management company brought an estimated 54,000 cubic metres of soil to a mountainside in Atami, Shizuoka prefecture, where the massive mudslide took place on July 3, reports Xinhua news agency.
Some 56,000 cubic metres of soil in total collapsed into a nearby river, damaging around 130 houses and buildings.
Most of the collapsed soil was left by the company, possibly exacerbating the massive accident.
Yamamoto Haruhiko of Yamaguchi University, an expert in landslides, told local media that the nature of the collapse warrants an investigation into possible links to the landfill.
"We believe the soil was brought in as landfill. It collapsed and made the disaster even worse," Namba Takashi, vice-governor of Shizuoka, told local media.
The soil brought by the real estate management company exceeded the amount that the company reported to the local authority, and it was found that industrial waste was mixed with the soil.
Moreover, the company, based in Kanagawa, was subject to multiple administrative directions by the prefectural and Atami city governments due to repeated inappropriate actions, according to the Shizuoka government.
The Geospatial Information Authority of Japan reported that the soil at the site increased about 56,000 cubic metres between 2009 and 2019, and around 48,000 cubic metres of the soil might have flowed out in the latest mudslide.
Based on the data from airborne laser surveys, the authority stated that because of the accumulation of soil, the site, which used to be a valley in 2009, was raised to about 13 metres in 2019.
After the mudslide, the central government has started to take actions to secure the safety of accumulated soil located nationwide, including the possibility of creating universal regulations.
Currently, Japan lacks comprehensive legal regulations covering soil accumulated for such purposes as residential land development or disposal of surplus soil.
"We need to establish firm rules and make sure they are followed by operators," Kazuyoshi Akaba, Japan's land minister, told local media, pointing out that the unregulated accumulation of soil poses a "high risk".
Local authorities warned the danger is not over yet because the ground is unstable and further landslides are possible.
They are monitoring the site around the clock and will create measures within a month to prevent any recurrences at the site.