Radioactive pollution has reached heavily populated Tokyo, Japan
When professionals seek to purify items, they often turn to fire as the great refiner. In light of the fact radioactive materials have crept into the water and soil in Japan, after an unprecedented earthquake and tsunami damaged the Fukushima nuclear plant, professional, CONTROLLED burning of segments of farmland, then fresh topsoil, would be beneficial in reducing some of the pollutants.
Tokyo
Following the scenario of how the nuclear incident unfolded, the radioactive elements involuntarily deposited into the water and soil should not be in their purest, undiluted forms, due to rain and excessive water. Therefore, the items would not be as volatile and combustible as they normally would, if fire is introduced to said soil. The plan would work, but it would have to be carefully executed by the government to prevent accidents (translation: don't burn the country down).
Fukushima Nuclear Plant
As for the water, Japan is going to need a greater national filtration system to trap and breakdown the pollutants streaming through the water. They cannot leave the pollution issue unchallenged. The government could also add a sparse amount of water purifying agents for a time, to their national supply, rather than standard fluoride, to address the issue. It would help. During emergencies in hurricane prone regions, when water cannot be boiled, very small, measured amounts of chlorine is added (but it should be properly measured per gallon of water, to avoid poisoning).
