Each year, California generates over 82.3 million tons of compostable organic material — from manure and prunings to food scraps and forestry biomass.

Feedstock Source	Estimated Annual Volume
Confined Cattle Manure	52.5 million tons
Forestry Biomass	14.3 million tons
Municipal Organics (e.g. food waste, paper, yard waste)	10.4 million tons
Agricultural Biomass (orchard prunings, seed waste)	5 million tons

If all of these materials were composted, California could produce an estimated 33 million tons of compost each year —– nearly one cubic yard per resident.

Current Composting Capacity	Sites	Tons Processed / Year
Commercial Composting	70	5.3 million tons
Agricultural & Green Waste Sites	142	1.4 million tons
Dairy-Based Composting	~80	~3 million tons
Community Composting	~220	~2,900 tons

According to the best available data, only ~9.8 million tons are currently processed into compost. Conversations with practitioners and agriculturalists suggest that this number may be underestimated, particularly for dairies. However, there is still far more available feedstock than is currently being composted, and instead it is driving pollution across the state.

This is a massive untapped opportunity that calls for smarter planning, scaled infrastructure, and policy alignment.

Resources:

[California Feedstock Inventory 2024]

[Compost Sites Throughput & Creation 2024]

[Data Gathering Methods]

See the [interactive map] for compost sites and feedstock concentration across the state.

What if we could close the loop? What if we replaced synthetic inputs with recycled nutrients to rebuild soil and protect public health?

The Carbon Project