The council says information tags are meant to be left on offending bins by the waste collection team.
It’s so the homeowner knows which item has caused a collection to be missed and they can remove it ahead of another collection.
However, there have been reports that tags aren’t being left by disposal crews.
And in some cases, passers-by are dumping rubbish in bins which means the owner doesn’t realise their bin is even contaminated when it's returned to them.
The council says when this happens, it may result in all recycling collected that day, from around 1,000 properties, not being recycled.
One resident claims their bin was delivered back to them with no tag explaining why it was "contaminated", and then not collected for another 5 days.