Composting for a self-reliant future

Sustainable Coastlines Hawaii, an Oahu, Hawaii-based nonprofit, is working to replenish Hawaii’s soil health through the use of a modular composting system. The organization recently received government approval to commercialize its operations and accept organics at its Waimanalo, Hawaii, composter. Sustainable Coastlines Hawaii’s goal is to produce nutrient-rich soil to revitalize the state’s agricultural industry.

“There’s so much degraded land in Hawaii from industrial agriculture,” Sustainable Coastlines Hawaii Executive Director Rafael Bergstrom says. “The benefit [of this composter] for the community is high in terms of soil restoration and being able to grow our food. Plus, the food that we have in Hawaii is import.”

Agricultural production in Hawaii has shrunk by more than 152 percent since 1980, according to a 2020 report prepared by the University of Hawaii at Hilo. Now, the U.S. Department of Commerce reports just 15 percent of the state’s food is produced locally.

This is partially because of the closure of sugarcane plantations in the state. According to the same report by the University of Hawaii, islands like Maui saw an 82 percent decline in cropped acreage when the Hawaiian Commercial & Sugar Co.—the last sugar plantation in the state—removed 38,810 acres of sugarcane production from the island in 2016. This has been partially offset by adding diversified crops, but it has not fully recovered.

The state also is home to pesticide testing fields. According to a 2020 report from Frontiers in Environmental Science, an environmental research journal, pesticides widely used in American agriculture pose a grave threat to organisms that are critical to healthy soil, biodiversity and soil carbon sequestration to fight climate change.

In 2021, Monsanto Co., St. Louis, pleaded guilty to two felonies and 30 misdemeanors for environmental crimes related to the illegal storage and use of pesticides on corn fields in Hawaii.

An organic start

Sustainable Coastlines Hawaii was co-founded by Kahi Paccaro. The organization employs nine full-time workers who spend their time hosting education programs, cleanup events and restoration work for the group.

Since its 2010 founding, Sustainable Coastlines Hawaii has become a leading organizer of ocean cleanups in the state. Now, the organization is expanding its efforts to include improving the island’s soil and self-reliance as it prepares for climate change.

According to Hawaii’s Department of Environmental Services, Oahu generates more than 2.2 million tons of waste annually.

Sustainable Coastlines first launched its waste diversion program in 2013 at an Oahu surfing competition called the Vans Triple Crown of Surfing. The organization collected material in bins that separated trash, recycling and compost. The organic material was then taken to a local farm and composted manually. To scale up composting operations, however, the organization’s leaders knew the system needed to be more efficient.

“As the scale [of composting] started to grow, we knew that there was a need for something more efficient than just composting by hand,” Bergstrom says. “As compostable alternatives to plastic started to come onto the scene, they needed an industrial complex and facility to break down properly.”

To increase its focus on composting, Sustainable Coastlines Hawaii partnered with Full Circle Solutions Hawaii. The company is based in Waimanalo on the island of Oahu and is devoted to creating premium, bacteria-rich soil from food waste and mulch from island tree trimmers. Sustainable Coastlines Hawaii approached the organization in 2020 with a proposal that Full Circle Solutions operate the composter at its facility, to which the company immediately agreed.

The Earth Flow composting system—manufactured by Green Mountain Technology, Bainbridge Island, Washington—is a retrofitted 20-foot shipping container. The system is compact and can fit in small areas, which is ideal for small communities like those on Oahu. It operates at Full Circle’s farm in Waimanalo.

The machine was paid for through grant funding that Sustainable Coastlines Hawaii received in connection with 11th Hour Racing, a philanthropic organization based in Newport, Rhode Island, focused on environmental conservation, and the Frost Family Foundation, a Makawao, Hawaii-based philanthropic organization focused on funding initiatives across the state.

Up to 1,000 pounds of material can be fed to the system daily. An auger churns the organic material front to back and side to side, introducing oxygen into it and accelerating the bacterial breakdown of the compost. The machine is powered by a Tesla solar battery.

Photo courtesy of Sustainable Coastlines Hawaii

According to Green Mountain, a control panel allows for automatic operation with multiple mix patterns and programmable timer cycles. The drive motors are controlled by variable frequency drives, regulating auger speed while minimizing the use of electricity.

“It’s a cool piece of technology because it’s so simple,” Bergstrom says. “This mitigates so many of the issues that are oftentimes associated with compost, whether that be odors, noise, off-gassing, fire hazards, pests or leachate. All of it is contained because it’s in a shipping container.”

Compostable materials can be added daily to the loading end of the Earth Flow. The typical processing time for the material to flow through the vessel is 14 to 21 days. As the material becomes compost, its volume is reduced by about 50 percent to 60 percent, allowing the compost to be unloaded about once a week.

The resulting compost is stored in covered bays that protect it from the elements and comply with local runoff regulations. There, the compost sits for up to 90 days.

Although it has not yet done so, Full Circle plans to sell the compost at wholesale prices in reusable buckets and other sustainable modes of packaging to avoid more plastic pollution.

The program processes organics from several organizations across the island, including schools, hospitals and food banks. It also offers an on-site drop-off location for residents, who can pick up finished compost for a $25 per month subscription. Sustainable Coastlines Hawaii plans to increase its composting operations through the Honolulu government and restaurants in the area.

Potential spoilers

While the composting system kicked into high gear earlier in the year, Bergstrom says Sustainable Coastlines Hawaii faces several obstacles that could hinder the program’s expansion.

Community outreach is a key challenge the operation faces. Bergstrom says people and organizations don’t know what can be composted, so collected materials sometimes contain vegetables wrapped in plastic or fruit with stickers. Some include other plastic materials in the organics that they drop off, thinking it will get separated before being processed.

“It’s a systemic problem that we’ve created in this society ... where we just basically let people think that it’s somebody else’s responsibility to manage their waste,” Bergstrom says.

“If we start seeing things like plastic bags in the collection for whatever reason, we’re not going to accept it from [that] location,” he adds.

Another obstacle to the joint operation is the collection contract the island has with H-Power, a municipal power plant that is owned and operated by Morristown, New Jersey-based Covanta. The waste-to-energy facility generates up to 10 percent of the island’s electricity, according to a report from Hawaii-based public affairs news organization CivilBeat.

“What’s happened on the island is we’ve invested a [large] amount of money in a waste contract that essentially incentivizes the creation of waste,” Bergstrom says. “About 30 percent of the waste that goes to the power plant is organic — a combination of food and yard waste.”

Covanta could not be reached for comment at the time of writing.

Bergstrom says the lack of a nuanced permitting process limits the state’s composting potential because of the high barrier to entry.

Recently, the group opened an education center on the farm where the composter runs. Sustainable Coastlines Hawaii says it plans to host classes and live demonstrations for students and the community to increase awareness of composting and spark interest in the waste and agricultural industries. Bergstrom says he hopes to replicate this operational model throughout the state.

“We’re not in the business of running full-on compost operations, but being able to source the funding to help create and expand the [state’s] network of composters fits into our mission of inspiring communities to care for coastlines because it’s all connected,” Bergstrom says.

The author is digital editor for Recycling Today Media Group and can be contacted at akamczyc@gie.net.