San Francisco collects 620,000 tons of food

San Francisco residents and businesses have composted more than 620,000 tons of material – mostly food scraps – through the city’s green cart program. By composting all that food since the program was created instead of sending it to landfill, San Francisco:

  • •Avoided creating 137,000 tons of methane gas, which the Environmental Protection Agency reports is 21 times more potent than CO2 as a greenhouse gas.
  • •Sequestered, or put back into the soil, 18,400 metric tons of CO2. That is the equivalent of keeping nearly 3,600 cars off the road.
  • •Created a total C02E benefit (methane avoided and carbon sequestered) of 155,000 tons. That’s equal to reforesting 35 square miles of sustainable forest for 23 years or offsetting emissions from all vehicles crossing the Bay Bridge for 311 days.

These numbers are based on a current, approved protocol set by the Climate Action Reserve. Jared Blumenfeld, director of San Francisco’s Department of the Environment, and appointee to head EPA Region 9, said “The reduction in air emissions achieved through the compost program represents real progress and tell us two things. We should compost all our food scraps, and this program should be replicated in many other cities. That would go a long, long way to reducing greenhouse gases.”

In addition to reducing air emissions, by placing food scraps in compost collection carts San Francisco residents and businesses help local farms improve soil health and structure, increase drought resistance, and reduce and even eliminate the need for supplemental water, fertilizers and pesticides.

San Francisco is striving to achieve two goals – divert 75 percent of waste from landfill disposal by 2010; and achieve zero waste by 2020. The board of supervisors approved Mayor Gavin Newsom’s call to make recycling and composting mandatory at all properties in the city. That law took effect in October 2010.

Recology, San Francisco’s recycling company, announced that city residents and businesses have placed more than 620,000 tons of compostable material, mostly food scraps, in green carts since the compost collection program started in 1996. While the city is doing a good job of recycling and composting, about 190,000 additional tons of food waste could still be captured and composted each year.

“We should never throw peelings, leftovers, coffee grounds or anything else we can compost in the trash. Instead place all materials that can be composted in a green collection cart; that is a direct and highly effective way to help protect the environment,” said Mike Sangiacomo, Recology CEO.

The potential to further reduce greenhouse gas emissions by continuing to replicate the San Francisco program is tremendous. Last year, according to the Environmental Protection Agency, some 32 million tons of food was thrown into landfills or incinerators, contributing mightily to greenhouse gas emissions.

By using improved systems, modern compost facilities limit and reduce air emissions and aim to preserve as much carbon in the finished compost as possible. Vineyards in Northern California that apply compost made from food scraps collected in San Francisco now use the soil amendment specifically to grow cover crops such as mustard and beans to pull carbon out of the atmosphere and sequester it deep in the soil. “This helps turn farms into carbon sinks,” Shaffer said.

More than 200 vineyards and farms in Northern California have applied compost made from food scraps collected in San Francisco.