San Mateo, CA Landscaping Rules: Composting (2026)

Composting requirements in unincorporated San Mateo County flow from California's SB 1383 (Short-Lived Climate Pollutants: Organic Waste, Lara, Chapter 395, 2016), implemented locally by the County Office of Sustainability with haulers (Recology) and RethinkWaste. SB 1383 requires everyone in California to keep organic waste - food scraps, yard trimmings, food-soiled paper, and similar materials - out of the landfill. Residents in buildings of four or fewer units must subscribe to curbside organics and recycling service through their local hauler and 'properly sort all food scraps, yard trimmings, and food-soiled paper, and place them in your curbside compost bin.' Multi-family building management must provide organics collection plus education and outreach. The County notes that almost 71% of waste it landfills is compostable material, and the statewide goals are to reduce organic-waste disposal 75% by 2025 and recover at least 20% of edible surplus food for people by 2025. Edible-food-generating businesses face separate edible-food-recovery requirements. Backyard or on-site home composting is encouraged as a complement (the County offers compost workshops), but it does not by itself exempt a household from the curbside-organics subscription requirement. The County warns that a business or residence found out of compliance may be subject to fines.