The clean-up of the Fukushima nuclear power station is heading towards a major hurdle.

Within just three years, the project will run out of space to contain its ever-increasing stores of radioactive water. As reported by Japanese newspaper Asahi Shimbun, authorities are now left struggling to know what to do with the water build-up before it's too late.

After being struck by an earthquake and a 15-meter (49-foot) tsunami in 2011, three reactors at the Fukushima Dai-ichi nuclear power plant in northeastern Japan suffered catastrophic meltdowns, in what became the second-most severe nuclear disaster since the 1986 Chernobyl event. While it's now estimated that up to 96 percent of the power plant can be safely accessed without protective clothing, it's expected to take another 30 to 40 years to decontaminate affected areas and complete the decommissioning of the plant.

As part of this ongoing clear up, around 1,000 specialized tanks were built to store the colossal quantities of water that flooded in from the tsunami wave or were used to cool the melted reactors. Some of the water has been treated through the removal of cesium, although much of it remains radioactive due to the presence of tritium, a relatively harmless isotope of hydrogen that's tough to separate from water.

There’s currently over 1.15 million tons of this radioactive water being stored at the facility in 960 tanks and it's continuing to accumulate at a rate of about 150 tons a day, meaning the tanks could reach full capacity by the summer of 2022.

So, what next? Japanese authorities and Tokyo Electric Power Co. (TEPCO), who runs the plant and are leading the clean-up process, met last week to discuss the few options on the table. Their panel brought forward a small handful of strategies, including the evaporation of the water, injecting it deep underground, or the construction of more long-term storage tanks.

They have also floated the idea of gradually pumping the treated water into the Pacific Ocean. This is the option favored by the International Atomic Energy Agency and Japan's Nuclear Regulation Authority, however, this is a hugely unpopular choice among local residents, fishermen, and environmentalists (for fairly understandable reasons).

“When we talk about Fukushima’s reconstruction, the question is if we should prioritize the decommissioning at the expense of Fukushima people’s lives,” Naoya Sekiya, professor of disaster social science at the University of Tokyo, told the Associated Press. “The issue is not just about science.”