Acts of nature are obviously not attributable, the same with a volcano eruption. If it's caused by humans attribution is possible.

Okay, so how far do your rights extend? If you have a right to no pollution on your land, how far can the nearest road be built?

I believe moving the goalposts from "water pollution" to "no pollution on land" isn't helping anything on the discussion, just makes it murkier.

The right to no water pollution comes from a moving resource, water passes by a property and goes to another, land doesn't move and hence could have less strict rules.