University of California, Irvine
OP-T2-23: Landscape Waste Composting

UC Irvine composts or mulches 100% of its landscape waste. In 2012, the green waste totaled 2,216 tons. The campus uses two methods of mulching: It uses self-mulching mowers on grass and annually chips 150-plus tons of tree limb material for planting beds and park trails on campus. The remaining green waste is collected daily by grounds keepers as they clip and trim, and is separated by source in the campus's recycle yard. The material remains in this state for two to three days to reduce moisture content and volume. The green waste is then loaded into 40-yard containers that typically hold 8 tons. UC Irvine takes two or three of these containers weekly to Waste Management's Sunset Transfer Station, which is 4 miles from campus. The material is ground and then taken another 8 miles, in even larger loads, to Tierra Verde located in the Great Park in Irvine, where it is composted using the traditional windrow method. The "cured" compost is sold by Tierra Verde in bulk or bags.