Cal. Public Resources Code § 4373

Any solid waste facility, for which a permit is required pursuant to Section 66796.30 of the Government Code, shall be maintained with a clearance of flammable material for a minimum distance of 45.7 meters (150 feet) from the periphery of any exposed flammable solid waste. (a) Any structure, building, or part of any structure or building located within 45.7 meters (150 feet) of the periphery of any exposed flammable solid waste shall also be maintained with a clearance of flammable material for a minimum of 45.7 meters (150 feet) from the periphery of the structure or building. (b) Sound and living trees may be left standing within the areas required to be cleared of flammable material, provided the following requirements are met: (1) Wildfire cannot travel into the canopy of any tree left standing. (2) Any tree left standing does not pose a fire safety threat or prevent fire equipment access to and near the exposed flammable solid waste. (3) All dead limbs, and all limbs within 3 meters (10 feet) of the ground are removed from any tree left standing. (c) Selected and isolated shrubs may remain within the areas required to be cleared of flammable material if all dead material is removed and each shrub is trimmed up so that fire cannot travel through the shrub canopy or pose a fire safety threat.