Some interesting replies in this sub-sub-thread :-)
It's clear that local councils are implimenting the rules in different ways: eventually I suspect they will all come together under a common scheme. One poster mentioned green wheelie-bins for green waste - round here the green WB is for *general* waste, and it's bags or boxes for the rest.
Black bin-liners left out by the WBs on collection day just stay there, if it isn't in a WB or the right sort of bag or box, it doesn't get taken.....
Having provided suitable means of sorting and collecting waste, I think they are only under an obligation to collect that. In any case if they don't meet their targets, they get fined.
It's called Democracy, and you get a sort of say every now and then.
It's proving so effective that less and less people feel the need to join in ;-)