Tens of thousands will visit UC Davis for its annual Whole Earth Festival. Question is, How much garbage will the participants leave behind. Organizers of the May 9-11 event, which traces its roots back to the first Earth Day in the 1970s, hope not much. They've set it up so that the three-day event will recycle perhaps as much as 90 percent of the waste generated. Food vendors are required to use certain materials, such as unbleached napkins, compostable bamboo utensils and recyclable plastic cups. Folks throwing things away can toss them at one of 15 "recycling stations" with containers for different kinds of waste. These will be emptied and sorted throughout the day by volunteers at the back of the campus Coffee House. And, say festival co-directors Rebecca Gmach and Tina Oliver, festival-goers are encouraged to bring their own cup, plates and dining ware. If they want tips on how to recycle at home, they can visit the festival's compost and recycling booth or talk to the self-described "recycling and compost mamas": Sarahini Chahal and Patricia Gehrels. Last year the festival recycled 60 percent of 160 cubic yards of trash, part of which was turned into compost used by the student experimental farm and a local cooperative.