Each year, for the past 10 years, Campus Dining has been sending an average of 236 tons of organics to be composted. Recently, these organics have been too contaminated to be composted effectively.
One year ago, Cal Poly began participating in the Zero Waste Units pilot program. In a collaboration between Associated Students, Inc. (ASI), Cal Poly Housing, Cal Poly Facilities and Campus Dining, disposal units were installed with slots for recyclables, garbage and compost in dining venues for students to use. From these units and the kitchen’s existing units, all compostable material was taken from the receptacles into dumpsters stored near the Eugene and Rachel Boone Dairy Science Complex (building 18).
Not long after combining previously compostable kitchen waste with organics from student diners, Campus Dining’s disposal company said its organics were too contaminated to compost. It found many of the noncompostable items were placed into the bins by students, which contaminated all the organics previously collected from the kitchen.
To combat this problem, Campus Dining acquired a second 40-yard dumpster for students to place their compostable waste so it does not contaminate the kitchen’s true organic waste again. The kitchen material is picked up by the disposal company Engel and Gray for use in compost, and the student organics are now sent to a landfill.
When the organics reach Engel and Gray’s facility, there is a highly calculated formula to create the best compost possible. As the correct carbon/nitrogen ratio is met, microbials (tiny living organisms) transform the organics into compost that can be used in landscaping. Ninety days later, the compost is ready to be distributed. Compost from materials supplied by Cal Poly may be seen at the Los Osos overpass or in Santa Barbara’s public landscaping amongst other places.
From an economical standpoint, Engel and Gray is not able to manually remove all the noncompostable material from the post-consumer organics.
“If you toss in a Snapple bottle and ketchup wrappers, that is all going into the compost,” said Bob Engel, Engel and Gray vice president.
According to Campus Dining Operations Manager Greg Yeo, the Campus Dining’s sustainability advisory board hopes to figure out how to train customers to lower the contamination rate.
Engel sees the problem occurring across the United States as people work to compost material.
“The problem is not just happening at Cal Poly,” Engel said. “People are dealing with this across the country.”
The Zero Waste Club works with Campus Dining to audit its disposal programs. Members of the club sort through a sample of the waste to help better target materials needed to educate students about what items to place in each bin. It then makes materials such as the backboards above the disposal bins to help guests place their waste in the appropriate locations.
Students and visitors at Cal Poly can do their part in the goal to reach zero waste by carefully sorting their garbage. For example, a Starbucks cup can be recycled, the stirring stick and heat sleeve can be put in compost and the lid and straw go to the landfill.
“If everyone takes part in carefully distributing their garbage to the appropriate bins, we can get the contamination rates to a point where our post-consumer organics can be turned into compost as well,” Yeo said.