On University of California campuses, there usually are two choices for throwing something away: the black garbage bin or the blue recycling bin. But increasingly, green also is becoming an option as composting programs spread at UC.

Recycling has allowed UC to divert more than 50 percent of waste from landfills, but the blue bins alone won't be enough to reach the system's objectives of diverting 75 percent of waste this year and becoming zero waste — sending no garbage to landfill — by 2020.

Implementing campuswide composting programs and educating people on using a green bin for organic waste are key to achieving such ambitious goals, set by the UC system's Policy on Sustainable Practices.

"We haven't hit the wall, but we're at a point where we're stuck around a certain level. There's only so much you can do to increase recycling," said Michelle La, program coordinator for the Waste Reduction and Recycling Program at UC Davis. "We have to take that extra step to reach that zero-waste goal."

Much of the material that winds up in landfills is organic. Capturing it through composting not only has huge potential to increase waste diversion rates, it's environmentally beneficial and can save UC money.

"Campuses are doing a good job of recycling and composting is the next step," said Lin King, manager of Campus Recycling and Refuse Services at UC Berkeley. "There's still a focus on recycling but by adding composting, together they are a holistic system."

Shrinking the carbon footprint

In addition to reducing materials sent to landfills, composting can help reduce carbon emissions and energy use. Mulch created by food scraps, tree and lawn cuttings and other green waste is sold to farmers for use as an organic fertilizer. That mulch then reduces the need for chemical fertilizers, which often are made from oil products and are energy intensive to create.

Composting programs for green landscaping and food waste are underway or being explored at all UC campuses. Last year, nine UC campuses surpassed a 2008 goal to divert 50 percent of their waste away from landfills. UC Irvine (79 percent), UCLA (77 percent), UC Santa Barbara (73 percent) and UC Santa Cruz (74 percent) had diversion rates above 70 percent in 2011-12, according to data from UC's Annual Report on Sustainability Practices

However, annual diversion rates are volatile due to the variable level of construction and demolition waste that is recycled each year. Diversion rates for can spike if there is more construction on a campus in a given year. For example, UC Berkeley diverted 95 percent of its waste during 2008-09 and only 57 percent in 2011-12.

A logical place to begin food composting is in dining halls at student dormitories, and that is where many campuses started their programs. Dining facilities at UC Berkeley, UC Davis, UC Irvine, UCLA, UC Merced, UCSF, UC Santa Barbara, UC San Diego and UC Santa Cruz have composting programs in place.

Larger scale efforts include the football stadiums at UC Davis and UC Berkeley, which are operating as zero-waste facilities.

The stadiums control input by selling only food and other items that are compostable or recyclable. Staff members help people place waste in the correct bin.

Lessons learned at the stadiums have applications to other zero-waste efforts. However, campuses are public spaces and the type of waste people bring onto campus can't be as controlled, but working with vendors to sell greener products and education on composting are vital components to becoming zero-waste, La said.

And composting — like recycling, which can actually turn a profit — costs less than sending the material to landfills, said Mark Rousseau, energy and environmental manager for Housing and Residential Services at UC Santa Barbara. The campus spends $72 a ton to send material to a landfill but only $48 a ton for its composting facility.

"It's always nice when it's cheaper to do the right thing," Rousseau said.

UC Irvine buys back its composted waste as landscaping mulch, looping it back to campus. The mulch also is cheaper than buying it from the vendor used before the campus started composting, according to Anne Krieghoff, manager of Solid Waste & Recycling Services at UC Irvine.

One challenge is that composting is still new enough that most cities don't have programs, forcing most UC campuses to seek their own waste haulers and compost facilities to process the material.

UCSF takes advantage of the city of San Francisco's composting program for residents and businesses through waste hauler Recology. The campus has composting in place at dining facilities and medical centers, and it is being rolled out in classroom and office buildings.

The learning curve

Another major challenge for composting is creating procedures that help people correctly separate items that are compostable or recyclable from landfill garbage, particularly at eateries and medical facilities.

At many UC restaurants and dining halls, staff members sort waste produced in kitchen and eating areas. At some eateries, consumers are expected to sort their waste. This practice will become more common as composting takes hold. Education is key to making the process work.

Detailed signage affixed with paper cups, paper plates, cans, bottles and other examples of what goes in each bin is effective, as is staffing waste stations with student volunteers or staff who can explain what goes where.

"Having the actual cup or plate Velcroed to the sign helps," said Adam Schnirel, recycling coordinator at UCSF. "We really try to make it as easy as possible with so many different products."

Often, student groups have helped start composting programs and are involved with educating the campus community on doing it correctly.

For example, at UC Berkeley, the Compost Alliance student group has worked with facilities managers to implement composting at nine campus buildings since 2010, funded by grants from the Chancellor's Advisory Committee on Sustainability, The Green Initiative Fund and the Alameda County Stop Waste program.

The goal is to create a centralized system for composting, and the group is working with UC Berkeley's Campus Recycling and Refuse Services and Physical Plant-Campus Services to devise a way to collect and haul away compostables throughout campus.

The group estimates that more than 18 tons of compostable waste has been diverted from landfills through its efforts.

While that amount equates to just a fraction of the 1,300 tons of compostables that were part of the 15,000 tons of waste produced on campus in 2010, "That shows you how much potential there is," said Annie Gorden, co-lead coordinator of the Compost Alliance. "It makes me cringe because all of that was going to the landfill before."