Japan's government to take 'firm measures' to stop radioactive water leaks at Fukushima Since a major leak occurred from a maintenance pit a month after three reactors at the plant melted following the disasters, TEPCO had denied any further leaks of radioactive water into the sea, despite repeated warnings by experts, until finally acknowledging them last month. The underground barrier on the coastal embankment has slowed the leaks somewhat, but has caused underground water to swell. To prevent an overflow above the surface, which is feared to happen within weeks, TEPCO will start pumping out about 100 tons of underground water from coastal observation wells this week. Later this month, TEPCO will remove old contaminated water from trenches near the coast - a time bomb that it had left untouched despite repeated prodding from the government. Shinji Kinjo, an official at the Nuclear Regulation Authority, said faster-than-expected swelling of the underground water following the installation of the chemical barriers accelerated the emergency caused by TEPCO's delays. Alarmed by the leaks, a fisheries cooperative in nearby Iwaki city decided to indefinitely postpone a test catch planned for September. Government officials said they were considering funding a separate, multibillion-dollar project to surround the reactor buildings with a wall of frozen ground to block underground water from entering the contaminated buildings. The project, announced in May, is scheduled for completion in July 2015. Similar methods have been used to build tunnels, but building a wall that surrounds four reactor buildings and their related facilities is "unprecedented anywhere in the world," said Chief Cabinet Secretary Yoshihide Suga. "We believe it is necessary that the country steps forward to support its construction," he said.