Tokyo Electric Power Co. began dumping groundwater from the Fukushima No. 1 nuclear plant into the Pacific on Wednesday, in a bid to manage the huge amounts of radioactive water that have built up at the complex.

The utility, which says the water discharged is within legal radiation safety limits, has been fighting a daily battle against contaminated water since Fukushima No. 1 was decimated by the earthquake and tsunami of March 2011.

Tepco said 560 tons of groundwater captured and stored before it entered reactor building basements was to be released Wednesday, using a bypass system that funnels it toward the ocean after checking for radiation levels.