What’s in our garbage?

In 2014, the Agency completed a study to characterize the municipal solid waste disposed by single-family residential, commercial (including multifamily) and self-hauled sources. Since the Agency’s last waste characterization study in 2007, the composition of the waste stream has changed, including a 30 percent decrease in the quantity of material disposed.

Currently, of the 262,500 tons disposed of in Sonoma County annually, approximately 66% or two-thirds, can be classified as divertible, potentially divertible, or compostable. The most prevalent waste from both residential and commercial sources is organics.

In the overall waste stream, plastic has increased substantially in relative proportion of the waste stream since 2006/07, almost doubling from 7.4 percent to 14.8 percent. All plastic material categories have increased, with the greatest increase in durable plastic items and recyclable plastic film. Organics have decreased mainly due to a significant decrease in food (from 21.4% to 17.3%). Most Construction and Demolition materials have decreased with the exception of clean gypsum board and rock/soil/fines.

Year 2014 Year 2007
Basis: 262,500 overall tons of waste annually Basis: 375,000 overall tons of waste annually
Overall waste stream
Organics 31% (including 17% food waste) Organics 36% (including 21%food waste)
Paper 20% Construction & demolition 27%
Construction & demolition 19% Paper 16%
Residential waste stream (single-family dwellings)
Organics 36% (including 15% vegetative and 5% non-vegetative food waste) Organics 51% (including 36% food waste)
Paper 18% Paper 19%
Plastic 15% Plastic 9%
Commercial waste stream (including multifamily complexes)
Organics 31% (including 14% vegetative and 6% non-vegetative food waste) Organics 42% (including 27% food waste)
Paper 24% Paper 21%
Plastic 18% Construction & demolition 15%
Self-hauled waste stream
Construction & demolition 48% Construction & demolition 64%
Organics 21% (including 6% food waste) Organics 14%

Definition: Organics
Organics includes food, leaves and grass, prunings and trimmings, branches and stumps, agricultural crop residues, manures, textiles, carpet, carpet padding and remainder/composite organics.

Definition: Construction & Demolition
Construction & demolition includes concrete, asphalt paving, asphalt roofing, clean recyclable wood (non-treated), other recyclable wood, treated wood waste, clean gypsum board, rock, soil and fines and remainder/composite construction and demolition materials.

Definition: Paper
Paper includes uncoated corrugated cardboard, paper bags/kraft, newspaper, white & colored ledger paper, computer paper, other office paper, magazines & catalogs, phone books & directories, other recyclable and compostable paper and remainder/composite paper.

Definition: Plastics
Plastics include PETE bottles (CRV), PETE bottles (non-CRV), other PETE containers (CRV), other PETE containers (non-CRV), HDPE natural bottles (CRV), HDPE natural bottles (non-CRV), HDPE colored bottles (CRV), HDPE colored bottles (non-CRV), other HDPE containers (CRV), other HDPE containers (non-CRV), #3-#7 bottles (CRV), #3-#7 bottles (non-CRV), #3-#7 other containers (CRV), #3-#7 other containers (non-CRV), recyclable plastic film, nonrecyclable film, durable plastic items and remainder/composite plastic.

For more details, view theSonoma County Waste Management Agency Waste Characterization Study, September 2014 (PDF: 1.42 MB). and the Sonoma County Waste Management Agency Waste Characterization Study, November 2007 (PDF: 979 kB).

Annual Waste Generated

By AB 939 California law, the California Department of Resources Recycling and Recovery (CalRecycle), requires the Agency, on behalf of the cities and the County of Sonoma, to calculate its diversion rate. The diversion rate is the percentage of total waste that a jurisdiction diverted from disposal at CalRecycle-permitted landfills and transformation facilities through reduction, reuse, recycling programs, and composting programs. Jurisdictions were required by law to achieve 50 percent diversion for the year 2000.

As of 2007, jurisdictions’ diversion rates were no longer calculated by CalRecycle to determine compliance with AB 939. Instead, a per capita disposal rate was used as a benchmark of program effectiveness. The statutory change was instituted by SB 1016 (2008).

As of January 1, 2020, the use of green material as alternative daily cover (ADC) will be considered disposal in terms of measuring a jurisdiction’s annual 50 percent per capita disposal rate.

Sonoma County’s Total Waste Generated

2018 3.9 lbs per person per day
2017 5.2 lbs per person per day
2016 4.6 lbs per person per day
2015 4.3 lbs per person per day
2014 3.6 pounds per person per day
2013 3.6 pounds per person per day
2012 3.4 pounds per person per day
2011 3.5 pounds per person per day
2010 4.1 pounds per person per day
2009 3.9 pounds per person per day
2008 4.5 pounds per person per day
2007 5 pounds per person per day*
2006 64%
2005 61%
2004 58%
2003 55.1%

*Per Capita Disposal Rate—The average amount of waste disposed within a county per person for a given year. This benchmark simply divides the total waste generated within a jurisdiction by the population (or sometimes employment data) and number of days in the year. The switch from a diversion rate to a per capita disposal rate simplifies the reporting process between a jurisdiction and CalRecycle and assists in a more timely evaluation of waste diversion progress.