Let's get to know and understand about ALPS treated water.

It is water that contains radioactive materials from inside the buildings of the Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Station, and has been purified and treated until it satisfies safety standards for all radioactive materials other than tritium.

For tritium, the water is significantly diluted with seawater before discharge so that it fully satisfies safety standards.
The tritium concentration after dilution is less than 1/40 of the safety standard (or 1/7 of the WHO standards for drinking water).

Because the water satisfies safety standards before it is discharged and the total amount discharged is also controlled, there is no concern about effects on human health or the environment.

* ALPS: Advanced Liquid Processing System. It is a system that removes multiple radionuclides from water.