Additional Projects

Aquidneck Island Planning Commission

Middletown, Rhode Island

DSM was originally retained by the AIPC to conduct a detailed feasibility analysis of options for closing the Middletown and Portsmouth transfer stations. Work included surveys of transfer station users, and an analysis of current subscription curbside users. DSM then compared the system cost associated with siting a new transfer station with implementation of a town-wide curbside refuse, recycling and yard waste collection system.

Town of Middletown, RI

Subsequent to the AIPC study, the Town of Middletown contracted with DSM to assist them with implementation of a town-wide collection contract funded through a Pay-As-You-Throw (PAYT) system designed to maximize recycling and yard waste diversion.

American Chemistry Council, Plastics Division

Washington, DC

Improving Curbside Recycling Collection Efficiency

DSM was initially contracted by the American Plastics Council during 1992 to participate in a three-year effort to analyze methods for improving the efficiency of collecting plastics for recycling. DSM managed the Springfield, Massachusetts model city project, which was part of a twelve-city project to test and analyze alternative collection systems for integrating plastic bottle collection with existing curbside and drop-off recycling collection programs.

Over the next three years DSM timed 2000 curbside stops in Springfield and Chicopee, Massachusetts, using the results to develop collection models based on regression analysis of the results. DSM also measured participation rates on numerous routes, both before and after public education programs had been implemented to evaluate various promotional strategies. Extensive sorting of garbage and recyclables was conducted, both on-route and at the Materials Recovery Facility, to determine the capture rate of recyclables and the amount of contamination set out for recycling.

Based on DSM's work in the Springfield, Massachusetts area, the APC asked DSM to compile the results from all twelve-model city projects into a comprehensive manual on improving collection efficiency for plastics and other containers. The manual, How To Collect Plastics For Recycling, published in 1995, has been used by municipalities around the United States to improve the efficiency of recyclable materials collection.

Improving Sorting Efficiency at Materials Recovery Facilities

The American Plastics Council contracted with DSM to manage a two-year project to investigate potential ways to improve sorting of plastic bottles at Materials Recovery Facilities (MRFs). DSM analyzed the full range of sorting conditions, input and outgoing materials, and costs at seven MRFs located throughout the United States. At each MRF incoming materials were sorted to determine the composition of the recyclables and contaminants, including the percentage of broken glass entering the MRFs. Outgoing materials were also analyzed to determine the amount of contaminants remaining in the sorted recyclables.

Video cameras were used to monitor manual and automated sorting rates by container type. The resulting videos were used to count sorting rates by material and to establish benchmark-sorting rates.

Finally, a detailed computer model was used to assess costs and revenues, by material, and ways to increase productivity and efficiency at the participating MRFs. The final report, How To Sort Plastics For Recycling, was used by MRF operators interested in evaluating and improving sorting system operations and cost effectiveness.


Capture Rate Analysis and Recycling Plan

City of Boston

Boston, Massachusetts

DSM worked with the City of Boston to improve recycling rates. Initial work concentrated on detailed sorting of curbside refuse and recyclables to determine the capture rate for recyclables, and the extent of contamination of recyclables set out for recycling. DSM then worked with the Department of Public Works and the Mayor's office to finalize a comprehensive strategic recycling plan for the City, including short and long term goals for multi-family recycling, leaf and yard waste collection, reuse, and management of unregulated hazardous waste.