The Central Otago District Council will have to raise rates if residents continue to contaminate their wheelie bins.
This week, the council put a message on social media saying it found an increase in contamination in the bins, such as general waste being mixed with glass.
The problem was especially bad in the Cromwell ward.
Council waste minimisation officer Sophie Mander said if it continued, the cost to manage recyclable materials would increase, which would be passed on through rates.
Glass from kerbside collections is taken to the Parkburn Quarry just outside Cromwell. The bottles are stockpiled, periodically crushed and used as an addition to roading aggregate.
For glass to be properly recycled residents must deliver bottles to one of the drop-off recycling facilities across the district, where they are separated by colour.
They are shipped to a glass furnace and bottle maker in Auckland.
Ms Mander said there were no plans to start sorting and recycling glass bottles collected from wheelie bins.
The council would review its waste minimisation strategy at the end of the year and one of the things which would be addressed is frequency of pickups.
Numbered plastics marked one to seven are transported to a sorting facility in Frankton. They are then sorted and sold.
