UCRRA presentation: contamination from 'wish-cycling' and single-stream sorting reduces recycling effectiveness

During a focused explanation of sorting and contamination, Eva Barnett told attendees that single-stream recycling—where all materials go in one bin—produces more contamination than dual-stream systems. "With dual stream recycling the contamination rate is 0.5 as much," Barnett said, and later offered approximate ranges: roughly 10–15% contamination under dual stream compared with about 30% for single-stream loads.

Barnett emphasized practical rules to reduce contamination: recycle by shape (bottles, jars, jugs, tubs and lids larger than a tennis ball) rather than relying on the chasing-arrows symbol, keep recyclables loose (no plastic bags), and make containers clean, dry, and empty. She warned that small items (Legos, bottle caps) and items that create tangles (bags, hoses) often fall out of sorting systems or shut them down and pose risks to workers.