Testing Single Stream Versus Dual Stream Recycling at CU

Submitted on July 1, 2010 - 6:39pm


University of Colorado Boulder


Jack DeBell, development director, CU Recycling

Project Overview

A new single stream recycling program was tested in CU's residence
halls and family housing courts during 2009. CU hoped that the added convenience would invigorate participation among the nearly 7,000 residents that live on
campus. Results showed that there was no appreciable increase in recovered materials, despite extensive outreach. In addition, the adverse financial impacts on revenue generation as well as the increase in contaminated materials prompted CU to suspend its test and institute an expanded dual stream recycling system instead.


Boulder County recently installed over $6 million in upgrades to its material recycling facility (MRF) to process single stream recyclables. This prompted the University to explore conversion to single stream.

Project Goals

Determine costs and benefits of converting to a single stream recycling operation.

Provide recommendations for near-term (6 months – one year) and long-term direction to the campus administration.

Project Implementation

The test was closely coordinated among the major recycling partners at CU: Facilities Management, Housing/Dining Services, and student government (who currently receives revenues from recyclables). Facilities Mangement and Housing both report directly to CU administration (while student government is comparatively autonomous).

The three main indicators (and before/after impacts on them) that would determine the outcome of the test were:
- tons per year recycling and landfill disposal
- costs per ton recycling and landfill disposal
- revenues per ton for recycling

Every effort was made to deliver effective outreach to students. In addition to the usual recycling instructions and encouragement delivered at the beginning of each Fall semester, there were several special activities designed to help ensure a successful test of single stream recycling. These activities included new signage, direct outreach through information tables in residence halls, and door-to-door "dorm storms".

Once the test was launched, data on each of the indicators was measured at least monthly using certified scale printouts and monthly market indices published in national trade journals.


The test took approximately six months to prepare. Preparation involved making certain that test parameters (tons per year recycling, landfill disposal costs per ton recycling, landfill disposal revenues per ton recycling) were accurately measurable. Preparation time was also spent designing and producing the educational materials used.

The actual test lasted a full academic year (August - May). Monthly weight tickets from a certified scale, along with market prices posted in trade manuals were used to ensure validity of the results.

After the test, several months were spent by the administration to review the results.


The project was financed with a $6,000 grant from Boulder County. These funds were earmarked mainly for outreach materials (signs, decals, etc) and staffing to implement the plan. In addition, the administration pledged to cover any significant revenue declines if the aqdditional tonnage did not offset the expected drop in prices paid for previously separated and more valuable materials.

Project Results

We have seen lots of contamination in the Single Stream recycling bins. People think that EVERYTHING can go in them. Often times, any increase in volume collected due to single stream is just an increase in contamination

Collection costs were not significantly decreased due to the single stream routing.

Revenues from selling materials as single stream were significantly less than when they were marketed as separate grades of paper and containers. Over $10,000 in revenues were lost as a result of the test. A portion of those lost revenues were covered by CU Housing administration.

Lessons Learned

We have found that keeping paper fibers separate from containers is important for a few reasons:
- papers do not get contaminated with food/beverage residue so they are not down graded and can be used for their "highest and best use"
- preserving more life cycles out of the papers will reduce the need for virgin resources from our earth
- broken glass often ends up in the paper fibers within Single Stream, making it hard or impossible for the mills to recycle without ruining their equipment
- we generate more revenue for our paper fibers separated from our containers

Supplemental Materials

Keyword(s): Research, Waste

Admin Dept(s): Facilities Management, Public Relations/Marketing/Communications/Publications, Residence Life, Student Government, Waste Management

Discipline(s): Environmental Studies and Sciences

For more information on this project, click here.