Composting at RCG
Pitfalls of Previous Efforts
Until the 2017-18 school year, UCSD's Housing Dining Hospitality (HDH) used to send their pre-and post-consumer food waste to Miramar Greenery for composting. However, due to high levels of plastics contamination in post-consumer waste, Miramar Greenery was forced to stop accepting it, resulting in a large amount of perfectly compostable food to go to landfill.
Additionally, University Centers (UCEN) sends their food waste to Otay Landfill's composting centers. While this is a laudable effort, the emissions caused by transporting actual tons of food waste represents a significant downstream carbon cost and is therefore not the most sustainable option. Furthermore, only a handful of businesses in UCEN actually participate in this endeavor.
To remedy the lack of participation by businesses in UCEN collection, Roger's Community Garden members concentrated on businesses that UCEN doesn't collect from. Our principle business include Jamba Juice, Lemongrass, Panda Express, Seed and Sprout, Subway, Tapioca Express, Y Mas, Zanzibar, in addition to the Art of Espresso (The Mandeville Coffee Cart). In Fall 2018, we added Perks Coffee Shop, Starbucks, and Sunshine Market, capturing pre-consumer waste from 12 of 22 businesses operated by UCEN.
Limitations & Streamlining
After several months of running our composting system, we've realized a number of potential improvements and the limitations of our current design:
The particular bin layout used makes it difficult to turn only a single pile
Our compost can become highly anaerobic due to the number of coffee vendors we collect from. Coffee has an extremely large amount of nitrogen in it, resulting in a disproportionate number of nitrifying bacteria settling in our system.
Oceanview Growing Grounds developed aeration methods to allow colonies of other bacteria to flourish. Their success with the Food2Soil method of forced air injection has had promising results, and it was promised to be replicated in the RCG system, which would help keep up with expansion whould we choose to collect from even more vendors.