Andy
To answer your question, the OM bins are all "chipped". The bins are weighed as they are emptied and the weight is obviously recorded along with the PIN number. When we get our half yearly bill for the bins, it tells us how much weight we've been charged for. The local dechetterie is quite good though as there are numerous bins for all sorts of items and we try if we can to dispose of heavier stuff in the "Tout venant" skip rather than in our bin at the house.
Here in Bristol, we have a bin extravaganza. Black wheely bin for general rubbish, green wheely bin for garden waste (this costs extra), green box for recyclables such as tetra-paks, oil, batteries and plastics, black box for glass and paper and a brown bin for food waste; cardboard is just left beside the boxes. And woe betide you if you put something in the wrong bin or box, it doesn't get emptied.