Basically Drivewasher is correct!
If you clean patios with high pressure water and no chemicals then your ok in the eyes of the environment agency/council etc, although if you use chemicals that are bio-degradable it maybe worth checking with authorities again, as its a grey area legally!
To clean bins legally, you need a waste disposal license, the vans they use for bin cleaning trap & recycles/filters dirty water, the bins then get sprayed with a pine type fragrent spray, this gets disposed of at a designated waste site or sewer drain!