Composting programs only work when the materials collected from residents are clean and free of non-compostable items. Even small amounts of contamination can affect the quality of compost, harm agricultural use, and lead to valuable organic waste being sent to landfill.
After noting a 12-15% green-cart contamination rate in 2015, Strathcona County launched the Gold Star auditing program, combining real-time data tracking with hands-on community engagement. Staff audit green carts, provide direct feedback to residents, and use targeted outreach to address common issues. Households that consistently sort their organics correctly are recognized with a gold star sticker, turning waste sorting into a visible and rewarding community norm.
Since the program began, contamination rates have dropped significantly from 2015 to just 1 to 3 percent. Each year, thousands of tonnes of organic waste are successfully diverted from landfill, contributing to cleaner compost, reduced emissions, and a stronger circular food system across the region.
