1. Impacts of a Change from Dual Stream to Single Stream Recycling
Lori Clark
David J. Tonjes, Omkar Aphale, Krista L. Thyberg
Department of Technology and Society
Stony Brook University

2. Using Recycled Materials in Manufacturing Reduces Carbon Emissions

3. The Big Debate: Evaluating Recycling Methods
Dual Stream
Higher quality
Higher collection cost
Set out confusion
Simpler MRF
Single Stream
Increased quantity
Less collection cost
Contaminated fibers
(glass)
More residues
Lower quality

4. Town of Brookhaven Switch-over: 2014 Three Districts Studied
Economic and Logistical Changes 1. Collection from alternating weeks to weekly 2. MRF company and equipment change 3. Pricing regime change Disposal cost: $80/ton + $20/ton L&T -Dual Stream: $20/ton processing fee, 80% revenues to town -Single Stream $20/ton paid to town

5. Tons Recycled Were Declining

6. Recycling Rates Increased Significantly
p< 0.05
Significant
p< 0.05

7. Revenue Stabilized

8. Disposal Rates Continued to Decline

9. Three towns
Waste sort
MSW
Recyclables

10. Recyclables and their Contaminants Increased
* = Significant
p< 0.05
Weissberger et al. PLOS Biology 13(4):e100228

11. Reported Residue Declined

12. The Total Waste Stream Changed: Recyclable Material Declined
* = Significant
p< 0.05

13. Non-recyclables in Total Waste Stream Increased

14. Source Separation Rates (Compliance) is Mixed
* = Significant
p< 0.05

15. Although Less Recyclables are Available, Set Outs Remain Constant

16. Observations Single stream increases curbside source separation
Mostly through inappropriate materials
No apparent operational impact
Continuing changes in the waste stream
but single stream seems to have “created” wastes
Maintaining recycling rates requires ever increasing separation efficiency
Still – fewer recyclables in the discards stream

17. Which method of collecting recyclables is better?
Dual Stream better quality costs more (2 pass) set-out confusion (alternate set-outs) simpler MRF capital, operating costs
Single Stream greater quantity costs less fibers contamination (glass!) more residues poorer quality set-outs
Green = data supports; red = data rejects; blue = did not test; gray = maybe …

19. lori. clark@stonybrook. edu david. tonjes@stonybrook. edu www