Local composting program turns food into fuel

Have you ever encountered a machine that can transform an entire turkey into black, rich compost within 21 days?

The Monterey Regional Waste Management District’s “Organics to Energy” program collects food waste from partners across the peninsula, transforms it into valuable compost and reduces landfill waste. Carmel High School participates in this program, but is currently suspended due to chronic contamination of its food waste.

MRWMD’s SmartFerm dry fermentation Anaerobic Digestion Unit has been up and running in Marina since 2013. The first Digestion Unit of its kind in California, it uses a special mixture of bacteria and heat to accelerate the decomposition turkeys…and a whole lot more.

Local entities such as the Monterey Bay Aquarium, Community Hospital of the Monterey Peninsula and CHS sign up and agree to separate food scraps from other trash. Haulers collect and transport it to the processing facility, where the food waste is rapidly decomposed into fertilizer and fuel.

In 2015, Carmel Unified School District began contributing food waste to this hungry machine and was the first school district in the state to do so. CHS amassed an average 25 pounds of food after every lunch period last year, all being sent to the digester. Almost everything from the CHS cafeteria is considered compostable. Yes, even potato forks, plates, napkins and boats as well as citrus and meat.

However, CHS food waste contributions are currently on hold due to high levels of contamination. Kimberle Herring, the MRWMD Education Coordinator, explains the types of impurities and the damage that they inflict.

“Most common contamination culprits include food-related packaging and service ware that is plastic, glass or metal,” Herring clarifies. “All can be a concern and harmful to the processing unit and to the end product—the compost.”

Herring emphasizes that the finished compost from the digester unit is not currently used by farmers on crops like lettuce and strawberries because of concern about physical contamination such as glass. Instead, compost is sold as fertilizer to local vineyards. The smaller market reduces economic prospects for the program.

CHS Environmental Science teacher Jason Maas-Baldwin explains that the reason for the current program hiatus on the CHS campus rests with the negligence of the student body.

“Sadly, students do not take the time to sort their trash into the right cans,” Maas-Baldwin laments. “Even if 80 percent of students take the time to carefully put things in each bin, there will still be too much contamination in the recycling and compost bins.”

Indeed, the MRWMD will not pick up the food if there is just a little bit of contamination. Furthermore, Maas-Baldwin points out that further harm is caused by each load of food that makes its way to the landfill.

“Sending compost to the landfill is not just wasteful; it wreaks havoc on the environment because the methane produced by decaying food makes our dumps the ninth biggest source of greenhouse gases,” Maas-Baldwin reveals. “What’s more, methane is more than 20 times more harmful to the atmosphere than the carbon dioxide that most of us worry about producing.”

If the food waste can be sent to the digester, methane is collected and used as fuel to produce electricity, which then provides energy to Marina’s water treatment plant.

According to MRWMD, after 21 days, the organic compost is removed from the digester building to complete its composting for the next 60 to 90 days in nearby wind-rows. It is then screened to remove any remaining contaminants and sold to agricultural users.

Katy Anderson, president of the CHS Environmental Club, anticipates that the compost collection on the high school campus could restart as early as February, and has renewed hopes for the program’s future.

“We hope to expand it, but first we need to make sure we have the information and education out there [to the student body],” Anderson details. “Accurate labeling will be key to help guide what gets thrown in the appropriate bins.”

The next time you see a compost bin on campus, Maas-Baldwin, Herring and Anderson ask that you do all of us a little favor—no Ziplocks or milk cartons please.

 

-Connor Suess