>"the water is treated and diluted to levels that are safer than international standards, and so far, testing by TEPCO and government agencies has found no detectable radioactivity in seawater and fish samples taken after the release."

Releasing contaminated water at a rate slow enough that it doesn't seem to raise ambient radioactivity levels certainly seems preferable to hoarding contaminated water that could be released en-masse due to another earthquake, weather event, containment failure, etc.