In Nasu and Nasu-Shiobara in Tochigi Prefecture, where decontamination work was carried out at primary and middle schools, about 11,800 tons of soil has been left in school compounds.
THE YOMIURI SHIMBUN
TOKYO — At least 140,000 tons of sewage sludge, ash and soil contaminated with radioactive materials has yet to be disposed of in Tokyo and six prefectures in the Kanto region of Japan following the crisis at the crippled Fukushima No. 1 nuclear power plant, a survey shows.
Under the central government-set criteria regarding radioactive materials, sewage sludge and ash with radiation levels up to 8,000 becquerels per kilogram can be put in landfills. But an increasing number of final disposal sites refuse to accept contaminated sludge and ash even if it meets the criteria, according to a survey by The Yomiuri Shimbun. In other situations, soil removed during decontamination work has been left at the original sites.
When The Yomiuri Shimbun asked local governments in Tokyo and six other prefectures with waste water processing facilities how they have handled sewage sludge, it found a total of 103,100 tons of sludge — including that which has been incinerated and reduced — was still at the facilities. Of that, about 52,700 tons was in Saitama Prefecture, the most among the seven prefectures.
The Yomiuri Shimbun surveyed 24 facilities in Tokyo and four other prefectures where radioactive cesium above 8,000 becquerels had been detected in ash.
The survey revealed about 6,500 tons of ash from general waste was still kept at the facilities. Of that, about 2,200 tons were in Ibaraki Prefecture and about 1,900 tons in Chiba Prefecture.
As for polluted soil removed in decontamination work, The Yomiuri Shimbun looked at 51 municipalities in five prefectures, which have been designated by the central government as areas for close contamination inspections, and found about 30,400 tons of polluted soil was temporarily stored there.
Many local governments in the Tokyo metropolitan area do not have their own final disposal sites for sewage sludge and ash.
The Nagareyama municipal government in Chiba Prefecture has about 750 tons of ash. The city previously sent ash to facilities outside the prefecture, such as one in Kosaka, Akita Prefecture, for final disposal.
However, since a maximum of 28,100 becquerels of radioactive materials per kilogram were detected in ash in July, such final disposal sites refused to accept ash from Nagareyama. Even ash en route to the disposal sites was returned to the city.
About 350 kilograms of the ash in the city meets the central government’s standard, but the city is not hopeful of finding a final disposal site.
“The central government’s criteria doesn’t do anything to gain understanding from residents around final disposal sites. Unless something is done, we’ll be forced to stop incinerating garbage,” a city official said.
In Nasu and Nasu-Shiobara in Tochigi Prefecture, where decontamination work was carried out at primary and middle schools, about 11,800 tons of soil has been left in school compounds.