If you’ve been throwing out forgotten leftovers from your fridge and fruit and vegetable scraps, like the majority of us, you’ve been letting go of a perfectly reliable resource.

There’s an alternative: composting.

In May, after almost a year of testing and Covid-related delays, the state Department of Health gave Sustainable Coastlines Hawaii and its partners approval to launch its Earth Flow composting system, the first of its kind in Hawaii.

Since its arrival in December 2020, its been housed at Full Circle Farm in Waimanalo, and operated by Full Circle Solutions Hawaii.

The Earth Flow composting system is a retrofitted 20-foot shipping container, designed by Green Mountain Technologies. The innovative system eliminates odors, pests and any liquid from decomposing material — and does it all quietly.

Inside the shipping container, a rotating spiral blade churns compostable waste, introduces oxygen and produces soil in two to three weeks. Though the soil needs up to 90 days to mature after initial processing, it’s still half of the six to eight months that composting typically requires.

Soon, a drop-off at Full Circle Farm will allow anyone to bring in unlimited household waste through a subscription and purchase the soil they produce.

Though the natural process of turning organic matter into soil has long been associated with funky smells and hard work — a deterrent to attempting it on a large scale — Sustainable Coastlines first implemented its waste diversion program in 2010, most prominently with Vans Triple Crown of Surfing, by setting up and collecting waste from receptacles that separated trash, recycling and compost.

The new composting operation is largely funded by grants from 11th Hour Racing and the Frost Family Foundation. The system itself was transported free of charge by Matson and Triple B from the mainland to Waimanalo.

The Earth Flow system, powered by a Tesla solar-powered battery installed by RevoluSun, can process a mixture of 400 to 700 pounds of food waste, and 300 to 600 pounds of green waste per day — over 180 tons per year. The solar-powered battery also produces energy for the office and education center at Full Circle Farm.

Rafael Bergstrom, the executive director at Sustainable Coastlines, thinks one of the main reasons food waste has not been composted on this scale in Hawaii is because most food is imported.

“We’ve kind of lost our connection to agriculture and we’ve become so far removed from our waste in our food systems,” Bergstrom said.

The composting operation is an opportunity to revitalize the land after the historical degradation of soil in Hawaii from pineapple and sugar cane farming and illegal pesticide use. Bergstrom hopes it’s the start of creating a functioning agricultural system.

What needs to first change is the way Oahu residents dispose of food waste.

On Oahu, almost all residential and commercial waste is sent to H-Power, a municipal power plant that incinerates it, produces steam to power a generator and creates up to 10% of the island’s electricity.

Oahu generates more than 2.2 million tons of waste a year, according to the Department of Environmental Services.

According to Bergstrom, around 30% of the waste sent to H-Power is organic, a combination of food and yard waste.

“If you live on Oahu and you’re at home and you have food waste, you put it in your garbage can — that’s all going to H-Power unless you compost it yourself,” Bergstrom said. “When it’s obviously a resource that could essentially be reused and put back into the land to grow more food.”

Bergstrom said he and his soon-to-be wife, Nicole, rarely throw away any food waste.

“We have a Bokashi Bucket (a home composting system) under our sink, and once it’s ready, we bury it in the yard to boost our outdoor garden beds,” Bergstrom said. “I also built some green waste compost bays in the back yard to break down branches and clippings.”

Some of the other composting sites in Hawaii solely focus on yard trimmings. But Bergstrom said food waste is vital to producing healthy soil because yard trimmings alone don’t contain all the nutrients essential for carbon and nitrogen balance in soils.

Composting food waste on an industrial scale also comes with a hefty list of requirements from the health department, which may be why the Sustainable Coastlines’ operation is the first one in Hawaii.

“When you start taking in food waste, you trigger a whole different set of permitting because there can be different contamination issues and all sorts of other things, especially with meat and dairy and oils,” Bergstrom said. “So the management is very different.”

The Earth Flow system was designed to churn anything that can be broken down and put back into nature, according to Van Calvez, the sales engineer at Green Mountain Technologies, a commercial composting technology company based in Washington state that created the system.

It essentially optimizes the conditions for natural hot composting, powered by bacteria that thrive at temperatures from 120 to 140 degrees, Calvez said.

“It’s kind of like an appliance, like a mixing bowl,” Calvez said. “But just like cooking, which requires a good cook and recipe to make good food, the quality of the compost comes from the quality of the ingredients that are used to make that compost. What we’ve provided is a very good tool.”

After two to three weeks inside the system, carbohydrates, sugars, and fats are broken down. What comes out already looks like finished compost, with no observable food waste.

Then it spends one to two months outside of the system being monitored and curing, allowing organisms to further break down the parts of the compost that are more resistant, such as pieces of wood and other organic compounds.

“When we say one to two months, that’s just a round number,” Calvez said. “Those fungal organisms continue to work over months and years to break down woody fiber.”

Once the soil has finished curing, it becomes stable enough for gardens, Calvez added, and no longer requires active management.

Sean Anderson and Gregory Williams at Full Circle Solutions Hawaii help the soil get to this stage at their farm in Waimanalo.

In 2012, Anderson started Green Rows Farm, a vegetable farm producing small-scale compost for its own use.

Seven years later, Anderson got together with his long-time friend, Williams, and they changed the name to Full Circle Farm with the intention of focusing more on compost, education and demonstration of regenerative practices. Full Circle Solutions was the result of their combined efforts.

When Anderson and Williams were approached by Sustainable Coastlines with the opportunity to host and operate the Earth Flow system, they said they both responded with a “full-body yes.”

Around the same time, Bergstrom had been pitching the composting operation to board members and potential partners. Bergstrom, once a pitcher for the Atlantic League of Professional Baseball, is no stranger to pressure, and secured funding for the composting operation in early 2020.

Over the course of 2021, Anderson and Williams gradually mastered the ins and outs of the Earth Flow system, and have now increased tenfold the amount of food waste they process.

The duo equated making compost to baking bread.

“You start with your recipe and you know how much flour and how much water to add, but sometimes it feels a little bit wet so you add a little more flour … that’s kind of how we’re using our senses to monitor the compost, because every load of food waste is different,” Anderson said. “We can tell whether it looks too wet or too dry or needs more mulch.”

Williams said they’ve been producing around 20 cubic yards of compost a month from a total of 20,000 pounds of food waste, the bulk of which is delivered by Food Bank Hawaii. Though they also receive food waste from Banan in Kailua and Blanche Pope Elementary in Waimanalo, and have plans to work with Aloha Harvest.

Sustainable Coastlines and its partners are also working on the addition of alternatives to plastics in their operation, such as certified compostable utensils that are plant-based and can break down.

Currently, they’re waiting for direction from the health department on next steps to test the viability of such products and determine effects on the soil, as there have been no regulations in Hawaii thus far.

When further testing is complete, the soil will be available for purchase in bulk rates of $250 for an unsifted cubic yard, and sifted compost for $20 in a 5-gallon bucket. Anderson and Williams said they deliberately chose 5-gallon buckets as opposed to plastic bags, to avoid creating another single-use product.

“At every option we have, our goal is to be a closed-loop zero waste operation,” Anderson said.

Sustainable Coastlines hopes this “closed-loop” philosophy will spread. Eventually, they hope to minimize the need to import food, and pave the way for policy change by showing the state what is possible.

Recently, Senate Bill 3004, which would provide cost reimbursements to farmers and ranchers who buy compost from a certified processor, was approved by the Legislature and awaits the governor’s signature.

So far, Maui and Kauai have both begun pilot projects they hope will lead to composting infrastructure statewide, according to Bergstrom.

Although Sustainable Coastlines is a beach cleanup organization, Bergstrom said composting was a logical next step. “If we’re making healthy soils, then we’re growing more food, we’re importing less plastic, and we’re creating more sustainable food systems that align with our mission” while releasing less plastic into the ocean.

To date, Sustainable Coastlines has retrieved 631,930 pounds of debris from beaches and various waterways, as it approaches its 300th clean up, thanks to its small staff and thousands of volunteers.

Besides growing more crops and using less plastic, Bergstrom added that healthy soil helps prevent runoff into the ocean. The runoff causes turbidity and overwhelms reefs, which both negatively affect water quality.

“It’s all connected,” Bergstrom said.

“Hawaii Grown” is funded in part by grants from the Ulupono Fund at the Hawaii Community Foundation and the Frost Family Foundation.