Only yesterday (July 9), the officials of this city in Chiba, which has had consistently elevated levels of radiation since the Fukushima accident, announced they had detected radioactive cesium in the ashes after burning the household garbage at its waste processing plants. Over 8,000 becquerels/kg (threshold above which they cannot bury the ashes) but only slightly over 10,000 becquerels/kg.
One day later on July 10, the city announced it was 70,800 becquerels/kg of radioactive cesium from the ashes.
From Mainichi Shinbun (7/10/2011):
Kashiwa City in Chiba Prefecture disclosed on July 10 that the radioactive cesium exceeding 70,000 becquerels/kg has been detected from the burned ashes at the city's waste processing plant. It is considered to be the result of the Fukushima I Nuclear Power Plant accident, and the city has halted burying the ashes since the end of June. At the current rate, the city will run out of space to store the ashes, and it won't be able to accept the household trash.
The national government set the guideline in June to temporarily store the ashes that tested 8,000 becquerels/kg [of cesium] or more, but there is no guideline as to what to do with the ashes after the temporary storage. The city plans to ask the national government to: 1) come up with a new standard for the final burial; 2) secure the space for temporary storage; 3) fully pay for the disposal cost.
According to the city, it is possible that the number was high because the residents cut grasses and clipped leaves and branches in their backyards trying to lower the radiation level and they were sent to the plants as burnable waste.
The city has two waste processing plants. The highest radiation of 70,800 becquerels/kg was measured at the Nanbu (southern) Clean Center in the three tests done since the end of June. At the Hokubu (northern) Clean Center, it was 9,780 becquerels/kg. When the ashes from the two plants were combined at the final disposal facility, it was 48,900 becquerels/kg.
The city accepts the average of 280 tonnes per day of burnable waste at its two waste processing plant, and buries the average of 21.3 tonnes of burned ashes at the final disposal facility.
Kashiwa City's website doesn't have any news or data on the radioactive ashes at its waste processing plants, and the last update of the Nanbu Clean Center web page was done on March 29.
If Koto-ku (in Tokyo) 's sludge plant is any example, the radioactive cesium from the burned trash may have been contaminating the downwind areas in Kashiwa City, a secondary contamination.