The correct answer to this open question is the following.
I think it is the government’s job to use laws to control these negative externalities but it is also the job of those company owners to have high ethical conduct and high morals to know that they are polluting the air and the water. So they had to be the first to have the initiative to come with a solution or a good plan to minimize air and water pollution, because one way or the other, they are poisoning the air and our waters.
Private sector and nongovernmental measures might work just as well if people have the consciousness of the damage they are doing with their policies.
What I am trying to say is that the federal and state government could have great environmental laws and regulations, but that is why they are laws, to be enforced. The issue is that, if company owners would be ethical and professional people, from the very beginning they should have implemented the right measures to minimize pollution, and not waiting until the law enforce them to comply with legislation.
ONe thing is to be forced to do something, knowing that there will be negative consequences if you do not do what you are told. And another completely different thing is to do things because you have principles, high values, and morals that always invite you to do things right.