This week a growing number of collections have been mixed with a variety of non-recyclable items such as textiles, food and nappies.
It means the contamination has to be painstakingly removed before being sent off to be incinerated – a process that can cost thousands of pounds.
Cllr Norman MacRae, Cabinet Member for the Environment, said: “We understand that with most residents at home, more waste is being generated but removing it is a costly and potentially hazardous process, particularly at this time.
“Please ensure your waste is put in the correct bin and store any excess recycling if necessary. If it is contaminated it may not be collected making the situation worse.”
Waste crews are instructed to check bins and leave a tag if they are contaminated asking the resident to re-sort it.
For a reminder of which bins to use see: