After confirming that more than 100 tons of highly radioactive water overflowed from a storage tank in February, TEPCO has decided to prepare observation wells to identify possible contamination of the groundwater.
The utility determined that three valves which should have been closed were left open, allowing the radioactive water to overflow, but still does not know why the valves were not closed.
Workers at Fukushima Daiichi are using pumps to recover some of the contaminated water, in other areas they are removing soil which was affected.
Tokyo Electric officials announced that they will dig three observation wells close to the leakage site on the ocean-side in order to monitor groundwater contamination.
If they do find contamination in the groundwater, TEPCO plans to dig a well in order to pump water out, but with limited storage space some experts have questioned whether TEPCO would be able to adequately store this additional water for any extended period of time.