The ministry said it found only five questionable cases, though it acknowledged a need for better oversight. Another probe, by the Health, Labor and Welfare Ministry found rampant labor violations — inadequate education and protection from radiation exposure, a lack of medical checks and unpaid salaries and hazard pay — at nearly half the cleanup operations in Fukushima.
About half of the 242 contractors involved were reprimanded for violations, the ministry said.
An Environment Ministry official in charge of decontamination said the government has little choice but to rely on big contractors, and to give them enough leeway to get the work done.
"We have to admit that only the major construction companies have the technology and manpower to do such large-scale government projects," said the official, who spoke on condition of anonymity, citing the sensitivity of the issue. "If cleanup projects are overseen too strictly, it will most likely cause further delays and labor shortages."
Minoru Hara, deputy manager at a temporary waste storage site in Naraha, defended the 3,000 workers doing the work — the only people allowed to stay in the town.
"Most of the cleanup workers are working sincerely and hard," Hara said. "They are doing a good job of washing down houses and cleaning up gardens. Such criticism is really unfair, and bad for morale."
Labor shortages, lax oversight and massive amounts of funds budgeted for the clean-up are a recipe for cheating. And plenty of money is at stake: the cleanup of a 20-kilometer (12-mile) segment of an expressway whose worst contamination exceeds allowable radiation limits by 10 times will cost 2.1 billion yen ($22.5 billion), said Yoshinari Yoshida, an Environment Ministry official.
"While decontamination is a must, the government is bearing the burden. We have to consider the cost factor," said deputy Environment Minister Shinji Inoue as he watched workers pressure wash the road's surface, a process Yoshida said was expected to reduce contamination by half.
The cleanup is bound to overrun its budget by several times, as delays deepen due to a lack of long-term storage options as opposition among local residents in many areas hardens. It will leave Fukushima, whose huge farm and fisheries industry has been walloped by radiation fears, with 31 million tons of nuclear waste or more. Around Naraha, huge temporary dumps of radioactive waste, many football fields in size and stacked two huge bags deep, are scattered around the disaster zone
The cleanups extend beyond Fukushima, to Iwate in the north and Chiba, which neighbors Tokyo, in the south. And the concerns are not limited to radiation. A walk through areas in Miyagi and Iwate that already were cleared of debris finds plenty of toxic detritus, such as batteries from cell phones, electrical wiring, plastic piping and gas canisters.
Japan has the technology to safely burn up most toxins at very high temperatures, with minimal emissions of PCBs, mercury and other poisons. But mounds of wood chips in a seaside processing area near Kesennuma were emitting smoke into the air one recent winter afternoon, possibly from spontaneous combustion.
Workers at that site had high-grade gas masks, an improvement from the early days, when many working in the disaster zone had only surgical masks, at most, to protect them from contaminated dust and smoke.
Overall, how well the debris and contaminants are being handled depends largely on the location.
Sendai, the biggest city in the region, sorted debris as it was collected and sealed the surfaces of areas used to store debris for processing to protect the groundwater, thanks to technical advice from its sister-city Kyoto, home to many experts who advised the government in its cleanup of the 1995 earthquake in the Kobe-Osaka area that killed more than 6,400 people.
But Ishinomaki, a city of more than 160,000, collected its debris first and is only gradually sorting and processing it, said the U.S.-educated Nakayama, who worked for the U.S. Environmental Protection Agency before returning to Japan.