Require Recycling and Composting

One of 42 options for reducing local carbon emissions, from our report Critical Cooling.

Urbanist Article
Annual savings potential:
Annual public cost:
Public cost per ton:
Implementing agency:

Horizon year:
186,700 tons
Revenue neutral
Department of the Environment, with Norcal Waste Systems


  • Mandatory recycling and composting helps the City reach its goal of 75 percent diversion, with an additional 166,000 tons of waste diverted
  • EPA WARM model used to calculate emissions is conservative, given San Francisco’s distance to landfill and efficiency of methane capture


A rule mandating citywide recycling and composting is expected to create a significant bump in San Francisco’s rate of diverting waste from landfills, currently at 70 percent. This is due to the fact that 63 percent of the remaining waste discarded in the city is readily recyclable or compostable. This policy not only will significantly reduce emissions, it also will do so at very low cost because residents and businesses pay the same rate or a lowerto shift trash capacity to compost and recycling capacity. Although emissions from waste were excluded in the City’s 2004 emissions inventory, this is one of the most cost-effective policies we can adopt to reduce emissions.

What we do now
San Francisco has the highest waste diversion rate of any city in the country, at nearly 70 percent in 2006. The City has a goal adopted by the Board of Supervisors of 75 percent waste diversion by 2010, and seeks to achieve zero waste by 2020. In recent years, the City has passed aggressive waste-related ordinances that have resulted in significant bumps in our diversion rate. Examples include the Food Service Waste Reduction Ordinance of 2007, the Construction and Demolition Debris Recovery Ordinance of 2006, and citywide composting – which has been available since 2000.1 San Francisco’s “Fantastic-3” program in partnership with Norcal Waste Systems has made it cost-effective for residents and businesses to sort recycling and compost, and the new Green Building Ordinance requires convenient access and adequate space for sorted waste streams in new buildings. However, progress toward the 75 percent diversion goal has slowed in recent years, with less than 1 percent in additional diversions in 2005 and 2006. The City believes that this rate is not likely to be achieved under voluntary participation programs alone. According to a 2005 report on San Francisco’s waste stream, 63 percent of waste put in the trash in San Francisco was either readily recyclable or compostable.2

What we could do
The Department of the Environment, which is tasked with helping the City reach zero waste goals, has proposed an ordinance to make recycling and composting mandatory. The Department of Public Works would be responsible for helping enforce the ordinance. Based on studies from other cities, the Department of the Environment staff believes that the mandatory ordinance will create a significant increase in diversion that will help the City achieve the 75 percent rate sought by 2010. The biggest bump is expected to be an increase in residential composting, as multifamily buildings will be required to provide equally convenient bins and commercial property managers must annually educate residents about separating waste streams. Compostable food makes up 40 percent of the residential waste annually disposed.

The Department of the Environment waste and toxics reduction budget is funded by Norcal Waste Systems, the City’s contracted waste hauler, at an amount set every five years through the garbage rate negotiation process. Using garbage rate proceeds, the department and Norcal each do a substantial amount of outreach and education on waste separation every year. The mandatory ordinance implementation can be achieved within the department’s current budget, as any additional staff costs could be covered through fees and fines associated with enforcement of the ordinance.

Carbon savings potential
A mandatory recycling and composting ordinance is expected to increase waste diversion by an additional 5 percent per year, beginning in 2010. Two million tons of solid waste are produced annually in San Francisco, so achieving 75 percent diversion translates to about 166,000 fewer tons of waste sent to landfills, compared to present rates.

To calculate carbon savings, we use San Francisco’s waste characterization study, plus national average practices for the recovery of methane gas from landfills, along with transportation distances from the Environmenal Protection Agency’s Waste Reduction Model. The annual savings from the additional diversions are the equivalent of 186,661 tons of carbon dioxide. This figure is high because so much of San Francisco’s waste sent to landfill is compostable. This compostable waste releases methane when decomposed, and methane is 21 times more potent than carbon dioxide as a greenhouse gas. However, even this high figure may be a conservative estimate: The national average landfill characteristics on which it is based include a 20 mile distance from source to landfill, butSan Francisco’s landfill is just more than 60 miles away in Alameda County. Furthermore, while the national average is 75 percent methane capture efficiency, according to one report, ours may be closer to 20 percent.

The cost per ton of carbon reduced from a bump of more than 5 percent in recycling and composting, as is expected from an ordinance requiring it, is zero – or revenue neutral.

2 “Waste Characterization Study,” prepared for the Department of the Environment by ESA, August 2005.