( CNN ) -- Japanese authorities are putting new pressure on the owner of the meltdown-stricken Fukushima Daiichi nuclear plant after its admission that highly radioactive water from the site has been seeping into groundwater and the harbor off the plant . A top official said Tuesday that the government wanted the problem solved `` as soon as possible , '' while an official at Japan 's nuclear regulatory agency told Reuters on Monday that the issue was an `` emergency . '' Three reactors melted down at Fukushima Daiichi after the massive earthquake and tsunami that struck Japan in March 2011 . The result was the worst nuclear accident since the Soviet Union 's Chernobyl incident in 1986 . The meltdown complicated an already historic disaster . Scientists have pointed to ongoing high radiation levels in the waters off the plant for more than a year to warn of an ongoing leak . The Tokyo Electric Power Company admitted to the problem in July , disclosing that it had found high concentrations of reactor byproducts tritium , cesium-137 and strontium-90 in test wells and in the harbor outside the coastal power plant . `` It 's a present reality that the contaminated water is seeping out to the bay without us being able to control it , '' Masayuki Ono , TEPCO 's acting nuclear power chief , said this week . `` This is an extremely serious issue we must tackle . '' Fukushima tuna study finds miniscule health risks . Ono said the company has built an underground barrier to prevent contaminated groundwater from reaching the sea , but it 's a difficult problem . `` We think we are containing the movement of contaminated water in general , but there is a risk of excess water going around or coming over the barrier , '' he said . TEPCO has been struggling to manage vast quantities of contaminated water at the plant since the tsunami , which swamped the facility . It 's still pumping hundreds of tons of water a day into the plant to cool the crippled reactors , though most of that is recycled . The problem now is what to do with groundwater that 's leaking into the damaged basements of the reactor buildings and passing out contaminated , said Michael Friedlander , a former nuclear plant operator and engineer . Radiation damaged more souls than bodies . `` Instead of fixing the wall in the basement to stop the groundwater leakage , they ca n't because the building is uninhabitable , '' he said . The result is the company is having to store the radioactive water in massive tank farms built around the site -- a makeshift solution with no good permanent fix , Friedlander said . `` Over time , they 've had radioactive water leaks on the property and there 's probably no question there is some seepage from the buildings themselves , '' he said . `` At the end of the day you have radioactive materials in places where they 're not supposed to be , '' and that contamination `` will migrate into places you do n't want it . '' The issue drew a sharp response this week from an official at Japan 's Nuclear Regulatory Authority , a new agency created in the wake of the disaster . Shinji Kinjo , the head of an NRA task force , told Reuters on Monday that TEPCO 's `` sense of crisis is weak . '' `` Right now , we have an emergency , '' he said . Man who battled Japan 's nuclear meltdown dies . And Yoshihide Suga , Japan 's chief cabinet secretary , said Tuesday that the government wants to see the problem fixed quickly . `` We are going to put our full efforts toward resolving the issues , '' Suga said . Sampling results disclosed in July showed concentrations of tritium in one well as high as 500,000 bequerels -- a unit of radioactive intensity -- per liter of water . By comparison , Japan 's maximum safe level of radioactivity in drinking water for adults is 300 bequerels per liter . Ken Buesseler , a U.S. marine chemist , was one of the scientists who raised alarms about ongoing contamination early on . Buesseler told CNN that building new groundwater barriers is may be a futile effort . Google maps show Fukushima nuclear ghost town . `` Think of groundwater like a river , '' he said . `` If there 's a flow to the ocean , you can put up a dam , but eventually it 's going to go up and over it or around to the sides ... It flows from higher to lower , and the ocean 's the low point . '' And Friedlander said that may leave TEPCO and Japan 's government with two choices sure to stoke further public anger : `` You can either dump it in the ocean , or you can evaporate it . '' `` At the end of the day , collecting 400 tons of water every single day is not a sustainable solution , '' he said . Federal officials allowed the Three Mile Island nuclear plant in Pennsylvania , the site of the worst American nuclear accident , to let contaminated water evaporate , Friedlander said -- but TMI was nowhere near the scale of the Fukushima disaster . `` We 're in uncharted territory here , '' he said . Japan signs deal with Turkey to build nuclear plant . CNN 's Yoko Wakatsuki contributed to this report .
Tainted water seeps from Fukushima Daiichi plant , plant owner discloses . Scientists have been warning about the problem for more than a year . `` This is an extremely serious issue we must tackle , '' TEPCO says . Storing the water `` is not a sustainable solution , '' U.S. engineer says .