My dad has an industrial recycling business. Basically he's just like all the other dumpster services, but instead of just bringing everything to the dump, he sorts all the material and brings them to different places instead of just straight to the dump. He's got special dump trucks that use a European hoist system.
He is also very well rounded when it comes to maintenance and working on engines, but he's old school. He does all his own maintenance on the heavy diesel equipment at his work.