Why no EPA inspections at Freedom Industries? They didn't need any!
http://www.allvoices.com/contributed-news/16321999-west-virginia-chemical-spill-company-was-exempt-from-epa-inspections
Thanks to our friends in the GOP, the only chemical plants that need federal EPA inspections are ones that manufacture chemicals. Companies that store and blend chemicals, like this one and the fertilizer factory in Texas, don't require inspections.
So you're thinking, "what about OSHA inspections?" OSHA is so small they have become almost purely reactive. Unless you do something really bad - like killing someone in through unsafe workplace conditions - and someone drops a dime on you, you probably will never see an OSHA inspector. The chemical spill was only detected because this product has a distinctive odor, and the townspeople reported smelling it...which means the leak had been going on for quite some time because that plant's quite a ways from population and the odor it creates is not strong.
One has to wonder, though, why someone was allowed to buy an abandoned oil refinery that was built in the late 1930s and convert it to a chemical facility without having the tanks inspected.