Solid Waste Composition Studies
To better understand the types and quantities of municipal solid waste disposed, and to assess the City's recycling potential, Seattle Public Utilities (SPU) has been conducting ongoing composition studies since 1988.
All files PDF format unless otherwise noted.
Waste (Garbage) Composition Studies
These studies provide information on the makeup of Seattle's residential, self-haul and commercial garbage, as well as construction, demolition and land clearing (CDL) waste. The overall success of Seattle's programs, education/outreach efforts, and variable rate structure can be measured by how much is diverted from the landfill, and how much recyclable material remains in the garbage. Measuring these two indicators is a large undertaking, so the waste composition studies are only updated every few years.
Residential Waste Composition
- 2014 Residential Waste Composition Study
- 2010 Residential Waste Composition Study
- 2006 Residential Waste Composition Study
- 2002 Residential Waste Composition Study
- 1998-1999 Residential Waste Composition Study
- 1994-1995 Residential Waste Composition Study
- 1990 Residential Waste Composition Study
- 1988-1989 Residential Waste Composition Study
Commercial and Self-Haul Waste Streams Composition
- 2018 Self-Haul Waste Stream Composition Study
- 2016 Commercial Waste Stream Composition Study
- 2012 Commercial/Self-Haul Waste Stream Composition Study
- 2008 Commercial/Self-Haul Waste Stream Composition Study
- 2004 Commercial/Self-Haul Waste Stream Composition Study
- 2000 Commercial/Self-Haul Waste Stream Composition Study
- 1996 Commercial/Self-Haul Waste Stream Composition Study
- 1992 Commercial/Self-Haul Waste Stream Composition Study
- 1990 Commercial/Self-Haul Waste Stream Composition Study
- 1988-1989 Commercial/Self-Haul Waste Stream Composition Study
Construction, Demolition, and Land Clearing Waste Composition
CDL waste composition studies are used to plan and design targeted C&D waste prevention and recycling programs for this significant waste stream.
Litter Can Composition
To help design and evaluate the citywide recycling can program, the City of Seattle conducted this study to determine the types and quantities of recyclable materials disposed within litter cans.
Recycling Composition Studies
These studies are designed to determine the quantities and composition of recycling set out by both single and multi-family residences within the City. Recycling composition estimates obtained from these studies are used to inform solid waste management planning and evaluation and to help determine a portion of the payment amounts from the City to the private company that processes Seattle's residential recycling.
- 2020 Residential Waste and Recycling Composition Study
- 2015 Residential Recycling Stream Composition Study
- 2010 Residential Recycling Stream Composition Study
- 2005 Residential Recycling Stream Composition Study
- 2000-01 Residential Recycling Stream Composition Study
Organics Composition Studies
In 2012, Seattle conducted the first in-depth evaluation of the city’s organics stream to determine both the composition of Seattle's combined organics stream as well as evaluate the accuracy of the sampling methodology given the variability in the amount and type of yard waste and food waste set out by residential and commercial customers that use plastic carts. Customers who use metal dumpsters or do not use City of Seattle contracted service were not included in this study.
- 2021-2022 Organics Stream Composition Study
- 2016 Organics Stream Composition Study
- 2012 Organics Stream Composition Study