Nine years after the Fukushima disaster shook the world, one of the biggest impediments to cleaning up the site in Northeastern Japan is coming from an unexpected source: The water.

That water, specifically 1.2 million tons of it, is still radioactive. Stored in 1,000 special tanks on the site of the nuclear power plant’s ruins, it’s taking up needed space – which the Japanese government plans to free up by dumping it into the sea.

But local residents, especially fishermen are opposed to that plan, telling touring reporters on the nine-year anniversary of the disaster that the water release would further damage the already battered reputation of fisheries – where sales remain at only half of what they were before the catastrophe.

Under discussion are two possible ways of disposing of Fukushima’s contaminated water. According to a government report released earlier this year, one possibility is that technicians could dilute the water to levels below the allowable safety limits, and then release it into the sea in a controlled way. The other is to allow the water to evaporate over the course of several years.

The dilemma over what do with the water is part of the complicated aftermath of the 9.0 magnitude earthquake and subsequent tsunami that hit on March 11, 2011. A wall of water destroyed cooling capabilities at the Fukushima nuclear plant and three of its six nuclear reactors melted down, forcing the evacuation of 160,000 people.

In the days that followed the quake, the Fukushima-Daiichi plant was rocked by hydrogen explosions, which burst through the roofs of the three afflicted reactors, sending radioactive iodine, cesium and other fission by-products belching into the environment. Millions of liters of water were pumped from the ocean to cool the overheating reactors, cascading contamination into the sea.

A clock, found in debris on a beach in Fukushima, stopped at the exact time the March 11, 2011 tsunami hit. Photo: - Credit: Nils Bøhmer/Bellona

Ever since then, the name of Fukushima has become synonymous with Chernobyl – the world’s other most notorious nuclear disaster – in connoting catastrophe, contamination and mass human evacuation.

Officials with Tokyo Electrical Power Co, or Tepco, say that the excess water they have collected must be disposed of so they can build facilities they need to begin the retrieval of radioactive debris within the reactors.

That wreckage is slated for removal by December 2021. Remote control cranes are being used to dismantle the cooling tower of the No 2 reactor, the first from which molten nuclear fuel was removed. Spent nuclear fuel stored in a pool at the No 3 reactor is being removed ahead of attempts to remove that reactor’s melted down fuel.

As the Associated Press reported, most above ground areas at the Fukushima plant can now be visited with minimal protective gear and a Geiger counter. The radioactive remains of the reactor buildings are, however, still off limits.

But areas underground beneath the plant remain extremely hazardous. Radioactive cooling water is leaking from the melted-down reactors and mixing with groundwater. The groundwater then must be pumped out to keep it from leaking into the sea. Other contaminated water – some of which was initially sprayed and dumped on the reactors while they were melting down – sit in other underground locations, leaking continuously into groundwater outside the plant.

Tepco has attempted to remove most radionuclides — like cesium and strontium – from the excess water, but the technology does not exist to cleanse it of tritium, a radioactive isotope of hydrogen. Coastal nuclear plants commonly dump water that contains tritium, which occurs naturally in nature, and Japanese officials insist it is harmless when ingested in small quantities.

But many are not pleased with Tepco’s assurances. Katsumi Shozugawa, a radiology expert at the University of Tokyo who has studied Fukushima’s groundwater, told the AP that long term, low-level radiation exposure in the food chain is poorly understood.

“At this point, it is difficult to predict a risk,” he told AP. “Once the water is released into the environment, it will be very difficult to follow up and monitor its movement. So the accuracy of the data before any release is crucial and must be verified.”