A comment appears that I don't entirely understand.
Yes, we do have an ongoing issue with bin contamination. This is down to various factors including language issues and the very high turnover of much of the Borough. However, we continuously communicate to residents via the Brent Magazine, the press, and door knocking. The last of these is the most labour intensive, and of course no method can be guaranteed to get through. However, the commingled system is actually less demanding for householders in terms of sorting than the old green boxes.