Buckinghamshire taxpayers had to shell out hundreds of thousands of pounds to deal with waste wrongly placed in recycling bins last year, figures suggest.
The Local Government Association is calling for labelling on packaging to be made clearer, to avoid recyclable waste getting mixed-up with non-recyclable items – an issue estimated to have cost English councils around £60 million last year.
Department for Environment, Food and Rural Affairs data shows 4,722 tonnes of waste collected by Buckinghamshire County Council were rejected at the point of sorting in the year to March – more than the 2,770 tonnes rejected the previous year and the largest volume since records began in 2014-15.
Overall, Bucks Council collected 246,306 tonnes of waste, up from 231,676 the year before.
Recycling charity Wrap, which works with governments and companies on sustainability, estimates that waste disposed of as recycling, which is then found not to be recyclable, costs councils around £93 per tonne to dispose of.
It would mean rejected waste cost taxpayers in Buckinghamshire an estimated £439,146 in 2020-21 alone.
Peter Strachan, cabinet member for climate change and environment at Bucks Council, said: “The figures quoted are for materials incorrectly placed in the recycling bins, like nappies or soft plastics.
"It’s unfortunate that so much material is being incorrectly put in recycling bins but we do work hard to try and educate residents on what they can and cannot recycle and will continue to do so.
"We have an interactive Waste Wizard which allows residents to search thousands of items online and gives guidance on whether they can recycle them or not.
"We also ask collection crews to leave reminders to residents who do make mistakes and have recently run a #100Days campaign which shared information on a 100 different items and how they could be disposed of properly.
“There is a cost to councils for rejected materials but it forms part of the contract with the Materials Recycling Facility and is not billed separately.
"We recognise this is still a cost borne by the council, however, and so we continue to work hard to improve the quality of materials sent for recycling from Buckinghamshire.
"We would always encourage anyone who wasn’t sure whether they could recycle an item to check online using our handy Waste Wizard tool.”
David Renard, environment spokesman for the LGA, which represents councils, pointed the finger at manufacturers who produce non-recyclable plastic packaging, which is then put in the recycling bin by people “in good faith”.
He said: “The burden then falls on councils to not only collect it and dispose of it, but to pay the extra cost of disposing of it.
“At a time when councils are working towards achieving net zero, they are doing so with one hand tied behind their back, courtesy of manufacturers who are littering our communities with plastic they know cannot be disposed of sustainably.”
Across England, 647,000 tonnes of recycling were rejected in the year to March, up from 525,000 tonnes the year before and the largest amount since records began in 2006-07.
Defra said a consultation had taken place on a proposal to force producers to label their packaging clearly, so that people would know if items are recyclable or not.
A spokeswoman said: “We want to make recycling easier and ensure there is a comprehensive, consistent service across England.
“Our landmark Environment Act will transform the way we deal with rubbish."