I doubt seriously that companies are going to risk going back to the 60's or 70's policies and products - even if the EPA wasn't there to stop them.
"Hand of the market" libertarian fairytale bullshit! History has shown, again and again, that the majority of companies will take the path that earns them the most money in the short term; damn the consequences. The few that don't, if no action is taken against the ones that do, are eventually forced by investors to adopt the same disastrous policies to remain competitive. The EPA is one option to try and prevent this behavior by giving the good companies some equalizing leverage against the bad actors, when all goes well.
so I think that the pendulum is definitely swinging towards conservatism and protecting the environment regardless of the party in political power at the time.
People seem to forget that the EPA was created by that liberal commie, Richard Nixon. [/sarcasm] for the sarcasm impaired. People in power, regardless of political party, who aren't in the pocket of the big, industrial polluters know that there needs to be a force against companies that wish to destroy the environment we live in for profit.
But even for all the good that the EPA has done, you still have companies like VW scamming the system. So saying that government is the solution really doesn't work either.
So, you're suggesting that since the EPA doesn't work 100% of the time, that it should be thrown away? By that logic, I'm sure that you have had failures and did not succeed 100% of the time. Should we throw you away as well? Look, the EPA has had failures, I don't dispute that. But, given the fact that the people that they have to report to (congress) has a leadership that has a vested interest in making sure that they can't work, they're doing an ok job. It comes down to if they are doing more good than harm. Right now, overall, they still fall under doing more good.
Reducing the federal government's size and scope doesn't necessarily mean that the functions it does will all disappear. Some will be taken over by other departments if they need to exist at the federal level, and some will be taken over by the states (where the founders of the country intended them to be).
Umm... other federal agencies cannot suddenly extend their mandate without authorization from congress. And, congress is not going to extend another department to take over the EPA because they already have a department to do the job... the EPA. You really think that that states would have any chance against the money of the gross polluting industries? The Koch brothers and their allies, all heavily invested in gross polluting industries such as coal, power generation, paper, timber and other such industries, have pledged just shy of 1 billion dollars in support of candidates that, in addition to other things, sign off on supporting the complete elimination of the EPA. (To put that in perspective, Delaware's entire projected 2017 annual budget is 4.1 billion dollars.) Do you really think that they're spending 1 billion dollars because they think environmental regulations can really be ran better by states or industry? Hell no! They're funding it because, if they can ram dissolving the EPA through congress, they feel they can make significantly more than 1 billion dollars by selling our planet's habitable future for profit. And if our planet is not habitable for future generations... well, that's not their problem.
Your solution, to put it in a metaphor: A fox gets past the hen house guard dog once in awhile and kills a chicken. Your proposal is the same as the farmer shooting the dog for not doing his job and saying to the chickens: "Sorry, you're on your own." and walking away; hoping the problem sorts itself out.