Ehhh, it's been as cleaned of radiation as possible. My dad did nuclear inspection for a living, including disposal, so I asked him about this when it first hit the news.
In theory, as long as they follow existing protocols, the water isn't going to be harmful. But that's the question, really; have they followed protocols? They have oversight, so it shouldn't be possible for then to half-ass it.
There really isn't a way to remove tritium though. The levels of that should be low enough to be unimportant.
It's going to be higher than background radiation, but well under international standards. It isn't something to be happy about, but it's as low risk as it gets. Tokyo pumps out way more dangerous things every day just by being a busy city.