Here in NZ most street drains go straight to the nearest stream. It's illegal to wash your car in your drive in many areas, because the chemicals in the washing and the stuff you wash off go into waterways (washing on your lawn is OK though). It's also illegal to have stormwater runoff pipes (eg from your roof guttering) going into sewers.
Funnily enough, my main knowledge on the subject was from a New Zealand(*) fly-on-the-wall programme, where they followed environment agency staff. They called in on one company which was washing equipment outside their property, and the drain outlet was straight onto a beach just down the road.
It makes sense to have this sort of setup - I just assumed that as in most of the UK, there is no handy river or stream nearby, the sewage system was used... Thinking about it further, though, it would probably smell a bit!
(*) I *think* it was NZ, but it could have been AU.. Sorry!
Biting the hand that feeds IT
