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San Francisco zero waste

Posted on
01 March 2012

Multiple benefits from mandatory recycling

In San Francisco, both composting and recycling became mandatory in 2009. The three-stream sorting system – compost, recycling, and trash for landfill/incineration – had been developed in pilot programmes and voluntary systems in San Francisco for more than a decade. The work was motivated by two main goals: by 2010 to achieve 75% diversion from landfills, and by 2020 to achieve zero waste – that is, no use of landfill or incineration.

San Francisco was awarded the title National Earth Hour Capital in Earth Hour City Challenge 2013

Keywords: mandatory recycling and composting, landfill diversion, zero waste, nutrient recycling, three-stream waste management

San Francisco motivates the composting stream based on multiple benefits. Landfills cannot expand infinitely and can cause serious environmental damage to air, water, and soil. Sending organic material (food wastes and plant cuttings) to composting, instead of landfills, decreases the amounts of gas – including the greenhouse gas methane – and leachate produced by a landfill, and increases a landfill's lifespan. Between 1996 and 2009, San Francisco's composting is estimated to have avoided 137,000 tons of methane, which is estimated to be 21 times more potent a greenhouse gas than carbon dioxide.

Benefits of composting
Composting can sequester carbon in the soil that is produced, also reducing greenhouse gas emissions. Between 1996 and 2011, composting's savings of greenhouse gases (in CO2-equivalent) was estimated at 354,600 tons. Also, nutrients such as non-renewable phosphate are recycled back to agriculture. Furthermore, given that land degradation and topsoil loss are worldwide problems today, the supply of high quality soil from composting is an important key for food security.

With regard to recycling's benefits, a long list includes economic savings, reducing the need for mining for new metals, saving energy from recycling glass, and not cutting new trees for paper.

Three-stream to zero
The basic elements of 3-stream sorting are: (1) The managers or owners of residential units, food establishments, and events must maintain colour-coded and labelled containers – blue for recyclable, green for compostable, black for trash – in convenient locations, and must educate expected users on what goes where. (2) By law no one may mix recyclables, compostables, or trash, or deposit refuse of one type in a collection container designated for another type. There is extensive and free support from the city for these goals, through public and private actors; for example, training, education, and signage (e.g. labels and signs for bins).

San Francisco's Environment Department argues that the city's Zero Waste goal will require more than composting and recycling, however. Producer responsibility, greater re-use, bans on polystyrene foam and plastic bags, and changed consumer habits – i.e. toward more durable products, less junk mail, etc. – are important and being pursued.

Learning by doing
San Francisco started in 1996 with collecting and composting food wastes from commercial establishments, e.g. restaurants (see also San Francisco farmers markets). In 1997, a pilot 3-stream programme for the residential sector began. It was called the Fantastic Three programme for the three colour-coded waste bins. Full-scale implementation of Fantastic Three started in 2000 and was completed by 2004, achieving an estimated 50% voluntary participation.

In 2006, San Francisco developed the Commercial Recycling Discount, enabling businesses to save 75% on trash bills through recycling and composting. Already in 2008, before 3-stream became mandatory, San Francisco had achieved a 77% rate of diversion-from-landfills. Between 1996 and 2009, San Francisco's composting is estimated to have avoided 137,000 tons of methane, which is estimated to be 21 times more potent a greenhouse gas than carbon dioxide.

Key success factors
All of these forerunner programmes enabled practical learning for the city and citizens, paving the way for the mandatory programme in 2009. The cornerstone was arguably California's 1989 law requiring all municipalities to achieve 50% diversion by 2000 or pay $10,000 a day in fines. California's approach is part of a global trend of required levels of recycling (see also Saxony and Curitiba).

Along with learning by doing, key success factors for the 3-stream approach include:
  • Making it mandatory
  • Positive press coverage
  • High environmental awareness among citizens
  • Recycling and composting infrastructure in place
  • Triple bottom line thinking: i.e. social, environment and economic, or ”people, planet and profit”
  • Continual outreach and education – in San Francisco, this includes a programme where six artists each work four months a year to create exhibitions using salvaged objects
  • Removing barriers to participation

Recology, 2009, “Huge emissions savings, other environmental benefits achieved through urban compost collection program”,

Recology, 2011, “S.F. compost program offsets emissions from all traffic on Bay Bridge for over 2 years”,

SFEnvironment, n.d., “Mandatory Recycling & Composting”,

SFEnvironment, n.d., “Zero Waste”,

Dan Sullivan, 2011, ”Zero Waste On San Francisco’s Horizon”, BioCycle Vol. 52, No. 7, p. 28 

Key data are retrieved from the UN World Urbanization Prospects: The 2011 Revision,, and from the UN Demographic Yearbook 2011,

Text by: Aaron Thomas

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