The Power of Rot
Changes in the works to turn food scraps from food service businesses into fertilizer and biogas
Even the smallest among us can play a role in protecting our planet.
Consider the mighty microorganism.
These wee ones will soon be joining forces with food service businesses and our regional and local governments to manage big-scale problems such as turning tens of thousands of tons of food scraps into fertilizer and biogas, and curbing climate change.
Food is the biggest component of what the greater Portland area throws away — enough food to fill 5,000 long-haul trucks a year. More than half of that food comes from businesses. When food gets to a landfill, it rots and generates methane, a potent contributor to climate change.
Two big changes are coming to our region that will put food scraps to better use: 1) new business food scrap requirements and 2) a new “anaerobic digester” that will turn food scraps into fertilizer and biogas.
Business Food Scrap Requirements gear up this Spring
For more than 15 years, Metro and local communities worked to keep food scraps out of landfills and put them to better use. Today, food scraps from participating restaurants, grocery stores and other businesses across the region are converted to compost at facilities nearby.
Despite these voluntary efforts, a lot more food can be captured. Food scraps diversion has stalled out at about 24,000 tons per year. So Metro Council adopted an ordinance that requires food service businesses in the Metro boundary to separate food scraps from garbage. Under the new ordinance an estimated 59,000 tons of food scraps will ultimately be collected per year.
Our local governments are gearing up this spring to notify food service businesses of these requirements and provide technical assistance in making the transition.
Impacted businesses
Implementation is phased based on businesses’ estimated volume of food scraps. Businesses that produce over 1000 pounds of food waste or more per week are required to compost by March 31, 2023. 1000 pounds is about four full 60-gallon compost roll carts.
Organizations that cook, assemble, process, serve, or sell food are required to compost their food scraps.
Grocery stores, restaurants & catering companies, food and beverage manufacturers are examples of the types of businesses impacted. Places with onsite cafeterias such as hotels, hospitals, corporate campuses, colleges and universities, nursing care facilities, and correctional facilities will also be required. Implementation for schools may have a different timeline in your area.
How do I get started?
Every business can access free assistance from local waste reduction specialists to help you determine when you need to comply with the requirement and provide free tools such as internal collection containers and labels. Specialists can also provide technical assistance on how to set up food scrap collection, donation and waste prevention practices. A specialist can also help businesses understand how this program affects collection rates in your area. Contact a specialist in your area
Biogas Anaerobic Digester under construction
Here’s where our friend the microorganism comes in
Currently food scraps from participating businesses go to nearby facilities in our region. These facilities work with air-loving microorganisms. Compost is laid out in large rows that are regularly “turned” to give the microorganisms air and mixed with yard debris to give them carbon to eat. Then these mini microbes do the work of turning our waste into fertilizer. This type of composting is ideal for residential material because homes provide a lot of woody debris from our yards.
Compost from the food service industry doesn’t have yard debris and can be harder to manage in compost piles. The food scraps from businesses are also high in nitrogen and are ideal for feeding the type of organisms that don’t like air so much. In fact, if you deprive these organisms of air, they become active and create biogas that can be captured for fuel.
Our region is poised to start working with these non-air-loving microorganisms!
Poop to Power
The City of Portland Columbia Wastewater Treatment plant has been capturing gas from sewage for years, generating heat and electricity to power the plant while selling a portion to a local business. But even with this reuse, some methane is still burned off, released to the environment as carbon dioxide.
Through the Poop to Power Project, Portland is on its way to maximizing the reuse of the methane produced at the treatment plant and turning this waste into a valuable resource. The City is retrofitting the treatment plant to receive food scraps and will deprive microorganisms of air to create biogas. The resulting renewable natural gas (RNG) will be used to replace dirty diesel in commercial vehicles.
Once the system is operational, food scraps from most of our region’s businesses will be sent to this “anaerobic digester”. The food scraps will be mixed with the treated sewage and fed to the microorganisms that produce biogas. There will also be a final product that makes excellent fertilizer for agricultural use.
Food Scraps vs Wasted Food
These two new programs are all about putting food scraps to better use. Food scraps are the leftover materials after prepping food to be eaten. Orange rinds, banana peels, carrot tops, eggshells are all ideal for food scrap composting.
However, edible food has its greatest benefits if it is eaten.
Project Drawdown identifies reducing wasted food as the second most important action we can take to curb climate change. Their scientists say, “A third of the world’s food does not make it from farm or factory to fork. Producing uneaten food squanders a whole host of resources—seeds, water, energy, land, fertilizer, hours of labor, financial capital—and generates greenhouse gases at every stage.” Interventions can reduce wasted food, thereby reducing overall demand on our planet.
Meanwhile, 1 in 4 Oregonians are food insecure and could use the food.
Businesses can find resources on food donation, tips on tracking food and strategies to avoid wasted food through Metro’s page on Preventing Food Waste. Businesses can also talk with the waste reduction specialist in their area.