@Saleem this is something I need to investigate further. If you have any useful links etc. I would appreciate very much.
I do know that in UK garages, nothing goes in the drain. All coolants, waste oils, brake fluid must be stored in bunded containers. Old rags, empty spray tins, used absorbant granules all go in their own container. Using sand or sawdust to soak up spills is a big no no. Old batteries go in a special sealed container. All containers etc. are collected by the recycling company once a month. For some things such as waste oil, batteries, you get money for recycling them. Other things such as coolant, rags etc. you have to pay to recycle them. The environmental agency carries out regular visits to ensure people are complying with the regulations.
The rules in scrapyards are even tougher. All yards must be fully concreted, draining into a receptor tank which separates oil and water from the runoff. Oil is emptied from the receptor and the clean water coming from the receptor is regularly tested for ph and contaminants. Any soil which has oil spilt on it must also be sent to the recycling centre. Even soil which has had plastic or tyres stored on it is classed as contaminated land. PCBs are also classed as hazardous waste so most scrapyards are not allowed to touch electrical equipment without a special licence. You also need another special licence to deal with fridges.
The environmental agency had the potential to cause a lot of headaches for me but i always did my best to ensure everything was kept legal. As long as you're making a genuine effort and not being an asshole about it, they will generally just tell you about any problems and give you a chance to rectify it. If you're an asshole, they just fine you first time and some of the fines have potential to bankrupt small businesses.