Tokyo Electric Power Co.'s admission Monday that radioactive groundwater from under the disaster-struck Fukushima No. 1 nuclear plant has reached the Pacific Ocean came about a month after the problem was confirmed.

Tepco had been taking groundwater samples from wells near the shore at the crippled plant to test for radioactive substances. It claims it only recently realized the water levels in the wells rose when the ocean tides did.

Tepco's slow action and tardy revelation, coupled with an apparent lack of coordination within the utility in sharing crucial data about the case, is making local fishermen increasingly distrustful of the utility.