[dragonwriter]

> The government's job, in this scenario, is to enforce contract law and property rights (via tort law) through its justice courts. Since the river owners and the polluting company (in our example) don't have a contract with each other, only tort law applies. Clearly the company damaged these owners' rivers downstream (let's suppose) so the courts will decide the company must either cease and desist (destroying the property of river owners) and compensate them for the damage caused, or offer to buy them out, or offer to draw a contract that the river owners would agree to instead of winning the lawsuit.

The governments job in the present US system includes that, and its demonstrable that that function of government alone is not sufficient to encourage polluters to take great pains not to pollute others property, especially with pollutants that are difficult to trace to a single source such that ascribing liability to a particular polluter is difficult.

You suggest that things like property tax, eminent domain, etc. are problematic to your vision of "private property" (which seems a lot more like sovereign territory than private property), but you don't actually trace any causal link between the features you complain about and companies' propensity to pollute, and the avenues you point to as solutions in a "private property" (by your rather atypical definition of the term) system are, in fact, avenues that are equally present in the existing system and which have proven insufficient to the task.