Yes because accountable regulation would exist as opposed to regulatory monopolies that cannot fail and be easily displaced.
So what you're saying is if another unaccountable private company (with no interested in protecting any of the national and public resources, mind) regulates another private companies dumping of toxic waste in a public and national resource this will be the perfect outcome?
Ah but the private company will be accountable assuming its being supported by paying constituents. If people desire clean environments and contract a company to keep said environments in check, a company failing to keep its part of the contract will not be paid and thus be quickly displaced by one that meets the desires of its constituents.