Earlier quoted context omitted.
You may be committing a tort or trespass, depending on how you do it. There are a great many works on this type of issue, and if you are looking for a complete answer, I suggest you read them. If you are trying to 'catch me out', your rhetoric won't convince me, nor is it likely to convince anyone else.
• Scenario 1 I build my factory next to your land. A byproduct of my factory is a bunch of polluted water, which drains strait onto your land, causing much damage. The tort system could deal with this fine [1]. You can easily prove that it was the pollution from my factory that damaged your land. This may not be a good way to deal with it, because (1) it takes effort to take someone to court, which many small landown…
My original point was not that Pigouvianism was ineffective, but that: "Pigouvianism is inherently intolerant and totalitarian, not libertarian, as it relies on imposing one's value judgements on others. Using a tax to force compliance rather than more draconian restrictions may be 'nicer', but is not Liberty."
[1] http://www.libertarianprepper.com/air-pollution-and-its-unex...
[2] https://mises.org/library/libertarian-manifesto-pollution