The council reported that contamination rates have fallen from 15% to 8% since the scheme’s introduction in March 2020.
In a statement released last week, the council said that this has led to other local authorities contacting its recycling and waste contractor, Veolia, to ask for details on the scheme.
Separate blue bags for paper and card were introduced in March 2020 and delivered to around 600,000 households.
Before the changes, residents were allowed to put paper and cardboard in the commingled recycling bin along with tins, plastics and glass.
Previously, the council said paper and cardboard was contaminated by broken glass which affected the quality, but is now sent directly to paper mills in the UK for recycling.
The council reported that it is now asking householders to drive the contamination rate down further by ensuring there is no paper or cardboard in the commingled bin, which is for all other recycling.
It added that if contamination is found in the recycling bin it can lead to the whole kerbside collection load being rejected which can cost the council around £2,000.
By introducing the blue bags, the council can ensure the waste stream is cleaner and can be recycled to a “higher quality” which has already saved “tens of thousands of pounds” for the authority.
Councillor Jonathan Price, cabinet member for environment at the council, said: “I’ve been so pleased to see how well residents have backed the new recycling initiative and this has led to some great results already – so much so that both ourselves and Veolia have had enquiries from other local authorities to find out more on our blue bag scheme.
“But we do not want to rest on our laurels – and I am urging all our householders to make sure that any paper or cardboard is put into the blue bag. This ensures that the recycling is of better quality and saving thousands of pounds for the council.”