Composting

CAW continues to promote waste diversion and the recycling of organics through composting. Compost is created through a natural process in which organics such as food waste and yard trimmings, in the right ratios, are placed in piles, rows, or vessels to decompose. The end product is a nutrient rich soil, or humus, that is used by gardeners and farmers as a soil amendment to improve soil health.

Why Compost?
Composting is good for everyone. As our landfills begin to fill to their maximum capacity we need to be more proactive in diverting waste from our landfills. Recycling organics through composting is an alternative method used for dealing with waste that results in a natural products rather than another landfill.

Composting also provides a cheap alternative to commercial fertilizers as it contains essential nutrients needed by plants, along with many other benefits that synthetic fertilizers don't have. Compost improves soil structure and texture, allows soil to hold more moisture and prevents soil erosion. Using compost also promotes healthy root systems which can decrease agricultural runoff.

With a small investment in time, we can all contribute to a growing waste problem, while at the same time enriching the soil and improving the health of plants for you and others.

Keeping the Organics Out
About 41% of the space in landfills can be attributed to organic waste, which includes food scraps and yard trimmings. When organic waste is disposed into landfills, methane gas is produced. Methane is a powerful greenhouse gas, 34 more times effective at trapping heat than Carbon Dioxide (CO2).

How to Start Composting

Backyard Composting Resources (CalRecycle)

Basics on Compost

Get a Compost Bin

Composting: A Greenhouse Gas Mitigation Measure

Ton for ton, composting reduces GHG emissions from organics management over any other management option.

Compostable organics make up 41% of California's overall waste stream, contributing over 12 and a half million tons annually to our state's landfills. In landfills, this material produces significant quantities of methane, up to 80% of which is not captured by a landfill gas system. Well managed compost facilities do not produce any methane. Composting offers an environmentally superior alternative to landfilliing organics that eliminates methane production, provides a series of economic and environmental co-benefits, and has a substantial impact on greenhouse gas reduction.

  • Composting organic material reduces GHG emissions compared to landfilling with energy recovery systems. According to the most conservative estimates, which fail to account for many (if not most) GHG-reducing benefits of composting, California could reduce its GHG emissions by one million MTCO2E by composting just 30% of the food waste that is currently being disposed into landfills. This is equivalent to the carbon sequestered by 26 million tree seedlings grown for 10 years.
  • Compost can significantly reduce agricultural energy demand. Plants grown in compost-rich soil require less irrigation because of the increased infiltration and storage capacity of root systems and the reduction of water runoff and evaporation. Research has shown that the application of compost can reduce the need for irrigation by 30-70%. Given that approximately 8% of the electricity generated in the state is used to run California's massive water supply infrastructure, a substantial decrease in water consumption would significantly reduce energy consumption.
  •  Composting provides nutrient-rich soils, which multiple studies have shown results in greater carbon storage in crop biomass.
  • The application of compost results in a reduced need for GHG producing petroleum-based chemical fertilizer, pesticides, herbicides, and additives. These chemicals are carbon-intensive in their production and emit large quantities of global warming pollutants during application and as they decompose in the soil. The use of compost can reduce the need for fertilizers for vegetable crops by 33-66%.
  • The application of compost greatly increases the amount of carbon sequestered in soil. Experimental studies have shown that increased carbon sequestration in soil from composting application was 6 to 40 tons of carbon per hectare.

Learn about what CAW has done towards advancing composting efforts:

  • AB 1826 (Chesbro)signed by governor Jerry Brown in 2014, requires businesses that generate organic waste to subscribe to a collection and recycling service for this material. 
  •  AB 1594 (Williams), signed by governor Jerry Brown in 2014, ended a perverse incentive in state law that encouraged the use of yard trimmings as landfill cover (ADC).

The following comes from the Institute for Local Self-Reliance (www.ilsr.org), a national nonprofit organization working to strengthen local economies, and redirect waste into local recycling, composting, and reuse industries. It is reprinted here with permission. Go to https://ilsr.org/compost-impacts/ to download the original content for your publications, and make sure to use the above attribution.