There is word coming out from TEPCO about the scale of the leak from Kashiwazaki-Kariwa. It is may have come from LLW storage drums, which tipped over due to the quake. 1.5m³ total was discharged into the Sea of Japan with a total activity of 60 kBq. In other words, a similar activity to the human body. Of course, this is now diluted across a very large expanse of water making it negligible.
Unless of course you're one of those naive people, conned into buying distilled water in slick packaging because it is branded "homeopathic" (because technically we could argue the Sea of Japan is now radioactive in a homeopathic sense), there is nothing to worry about.