Cost Avoidance for Curbside Collection of Recyclables (City of Seattle, Washington)

GBB completed a Recycling Economic Study for the City of Seattle, Washington.  GBB evaluated the total solid waste system cost impact of the City’s planned curbside collection program.

To help the City of nearly 490,000 residents to analyze its avoided costs, GBB looked at savings over 5- and 10-year periods.  Using a computer cost model, two base cases were run short-term and long-term — as well as several alternative cases, to determine the sensitivity of the system to changes in various assumptions, such as the future rate of inflation.  The Seattle Solid Waste Utility divides its solid waste collection and disposal system into several distinct “cost centers” for accounting purposes.  The cost or profit was calculated for each center’s operation; this information was then compiled and used as a basis for establishing system-wide disposal rates.  In a sense, the new curbside recycling program becomes another “cost center.”

To aid in the analysis, the model was programmed to calculate the net savings or loss, from the impact of the curbside program in the year of its occurrence, the dollar value of that savings or loss, and the net present value of all savings and losses for the term of the study.  Pertinent factors regarding the curbside collection systems, general and administrative issues, the existing refuse collection system and transfer/haul operation, and the City’s landfill disposal site were taken into consideration in the study.

Based on the results of the cost analysis, GBB concluded that, over a 10-year period and based on 75 percent of the collected materials tonnage being new, the curbside recycling program would be financially beneficial to the City.  The curbside recycling program was, therefore, recommended on a financial basis for implementation by the City.  GBB also completed a study that described the disposal options available for the remaining fraction of the waste stream not recycled, including municipal solid waste composting and resource recovery.