You're right in saying that the libertarian would say that a person is responsible for their own actions, but your argument lacks completeness. A company which pollutes water at large would suffer the consequences of its own actions. People aren't stupid; they'd notice the contamination and act.
Your argument implies a lack of faith in a single person or a small group of people to effect change. Do you believe that only government has the ability to keep our water clean?
Your argument implies a lack of faith in a single person or a small group of people to effect change. Do you believe that only government has the ability to keep our water clean?