[madsbuch]

I think this comment very well encompasses the modern discourse on sustainability: With a complete lack of a principle of proportionality.

The problem by elevating the seriousness of flushing a toilet, is that it dilutes more severe cases where one could do an actual impact.

[Archelaos]

The problem is that people think there is a lack of proportionality until they discover that there reall isn't. That happend again and again. And this is the reason why an ecologically sensible society fights on all fronts. There are reaons why you are not allowed to flash anything down the toilet, there is ongoing research how to improve wastewater management, etc., etc.

To get back to the original issue: the OP told us that the dumping of Tritium does less harm than other discharge and thus we should look elsewhere for improvements. As I understand this sentence, he means we should not worry about it at all. This is out of proportion: he could have claimed that we should worry less about it, but it does not follow, that we should totally ignore it.