Over 16 years we have used several waste disposal collectors, all bought out by safety kleen. we now use safety kleen, they are efficient and the largest if not the cheapest, as has been said they recently bought out midland degreasing, who used to da a great many Unipart car care centre's, not that this will help you but they have two price lists one for midland (Cheaper) and one for there own.
The paper work is simple you get a transfer note for all they take, and you file it, so if HSE come calling you can demonstrate that you are having your waaste disposed of correctly, we have had two visits and this is all they ask.
we add a 2.50 enviromentle fee to all our invoices, if everyone want a clean world (ME INCLUDED) it has to be paid for, to date we have had very little resistance and they only one i remember was some toff who thought his S--- dont stink.