In a statement, the Timaru District Council said contamination in recycling was about 25%, which equalled about 540 tonnes of recycling going into landfill because of contamination.
This shortened the life of the landfill at a significant cost to the community.
From this week, households who ignore three warnings will have their recycling collection suspended, and the yellow bin lid will be swapped for a white one to make it easier for the truck drivers to identify.
The red, green and blue bins will continue to be collected following a suspension.
Waste operations manager Grant Hamel said the vast majority of the community made the effort to recycle properly.
"But there are still a small number of households putting inappropriate items such as dirty nappies in the recycling bin, which can mean a whole truckload has to be sent to landfill."
Enviro NZ would send a staff member to check the bins at random, and they would tag any that contained inappropriate materials.
The new rule was not about causing anyone embarrassment.
"The white lids are simply a way for the people in the trucks to easily identify which bins are not to be collected."
After the third time in a 12-month period where a bin was found to be contaminated, a white bin lid would be installed.
A final notice from the council would be given to a member of the household to sign and return to say they would use the bin properly in the future.
If the letter was not returned with a signature, the white bin lid would be installed by the contractor and it would not be emptied.
To support this initiative, updated information about what goes in each bin would be going out to the community in the upcoming rates bills, as well as being advertised through usual council channels.
These items can go in your yellow bin:
- Any plastic with a number 1, 2 or 5 inside the recycling triangle.
- Containers — rinsed with no lid.
- Empty aluminium cans — clean with no liquids left in them.
- Paper — including flattened cardboard, books, junk mail, newspapers and magazines.
- Tins — well rinsed (with loose lids placed in the red bin).
