CA SB279

Expands the permit exemption for small-scale composting by eliminating the 750 square-foot limit and increasing the maximum feedstock and compost allowed onsite from 100 to 200 cubic yards, or 500 cubic yards for public agency-owned composting operations

Creates a new exemption for composting agricultural materials from large-scale biomass management events (such as orchard or vineyard removal) at agricultural facilities, limited to once every 10 years with composting not exceeding 24 months

Increases the annual limit for giving away or selling compost product from 1,000 to 5,000 cubic yards for excluded tier and certain notification tier operations

Authorizes the Department of Resources Recycling and Recovery to further increase these volume limits through regulation

Requires operators using offsite agricultural materials for large-scale biomass event composting to maintain records of material origins for at least five years