So, you're wondering whether the government is going to catch you? The odds are good that you'll be caught - sooner or later. It's just that the government's enforcement activities, like all government agencies is based upon nutty, illogical, politically-motivated methods. In short, they go after money; but money from two main sources - big companies with deep pockets (who they charge massive penalties for often minor infractions) and small companies (who get charged whatever the agencies think they can get away with). Medium sized companies seem to get off-scot free (because they employ people in the area of jurisdiction and they haven't got big bucks the agencies want).
My opinion is that if the EPA and state agencies really cared at all about the environment, they would start conducting unannounced random inspections of all sizes and types of companies, using the business license lists. Fat chance of that happening. They rather go after easy money and companies too small to fight back against often absurd charges. Meanwhile, the really bad ones get away with dumping.
I would love to hear your stories of inspections and enforcement actions - both deserved and undeserved - just email them (anonymously, is fine)