Japan’s environmental minister has said the country may have to dump more than a million tons of radioactively contaminated water from the wrecked Fukushima nuclear plant into the ocean as storage runs short, sparking outrage among fishermen and environmentalists.

Tokyo Electric Power Co, or Tepco, the Fukushima plant’s owner, has been collecting the water, which has been used for cooling the cores of stricken reactors since they were hit by a tsunami in 2011.

“The only option will be to drain it into the sea and dilute it,” the minister, Yoshiaki Harada, told a news briefing in Tokyo, according to the Japan Times. “The whole of the government will discuss this, but I would like to offer my simple opinion.”

The water buildup at the Fukushima plant has long been a concern. Ever since the plant was ravaged by the disaster, Tepco has had to store contaminated cooling water in hundreds of special tanks it has brought to the site.

By now, the water levels are becoming critical and Tepco is running out of space to store it, prompting Harada’s remarks at a press conference on Tuesday.

TEPCO said it will no longer be able to store anymore water by 2022, the Japan Times reported, but the minster offered no specifics in terms of how much water should be dumped into the ocean. TEPCO officials have yet to comment on the minister’s remarks.

Tepco has attempted to remove most radionuclides from the excess water, but the technology does not exist to rid the water of tritium, a radioactive isotope of hydrogen. Coastal nuclear plants commonly dump water that contains tritium, which occurs naturally in nature, into the ocean.

But Tepco admitted last year that the water in its tanks still contains contaminants other than tritium, the Guardian reported.

Water storage tanks at the Fukushima site. Credit: Tepco

Japanese government documents leaked to Britain’s Telegraph in October of last year would seem to confirm this. According to the report, the water still contains radioactive toxins like strontium, iodine, rhodium and cobalt in amounts that are “above legally permitted levels.”

According to the Telegraph report, these radionuclides could build up in the fish and shellfish that are such an important part of Japan’s fishing economy. Strontium accruing in the bones of small fish could lead to bone cancer or leukemia when consumed by humans.

Fisheries groups in Japan swiftly condemned Harada’s remarks at the Tuesday press briefing. The statements are “thoughtless, in light of his position,” as environmental minster, Tetsu Nozaki, head of the Fukushima Prefectural Federation of Fisheries Cooperative Associations, told the Japan Times. “I want calm discussions to be held,” he said, noting that a relevant government committee is continuing to discuss how to dispose of the water.

Nearby South Korea is also displeased about the impact such a dump would have on its own seafood industry. In August, Seoul summoned a senior Japanese embassy official to explain how Fukushima Daiichi’s waste water would be dealt with, the Guardian reported.

One recent study by Hiroshi Miyano, who heads a committee studying the decommissioning of Fukushima Daiichi at the Atomic Energy Society of Japan, said it could take 17 years to discharge the treated water after it has been diluted to reduce radioactive substances to levels that meet the plant’s safety standards.

Shaun Burnie, a senior nuclear specialist with Greenpeace Germany told Reuters that Japan should commit to longterm storage of the water and rid it of all radioactivity including tritium.