I think if you banned all automotive work at home (including oil changes) that would reduce the amount of environmental damage like this. It's far easier to catch someone changing oil than dumping it. However there are obvious socioeconomic reasons why I don't think this is something that should be done.
I'm not proposing a solution, I'm just pointing out we shouldn't ignore the environment here. Or expect poor people to care about the environment because they very much do not. I know the people that do this and if I challenged them on it they would say "the government pours oil on their own gravel roads to keep the dust down anyways" or "if the government cared about the environment they wouldn't have killed Stanley Meyer" or some other claim to point out perceived hypocrisy.