Plans are underway to clean up the sludge at Hawaii island’s Waihonu Pond using the “genki balls” that have been used at the Ala Wai Canal on Oahu.

Susan Osborne, president of the Rotary Club of Pahoa Sunset, last week requested funding from the Hawaii County Council’s Regenerative Agriculture, Water, Energy and Environmental Management Committee to clean sludge, or organic waste buildup, from the fishpond.

Osborne said 250,000 people visit the pond, in Hilo’s Liliuokalani Gardens, every year. Efforts from various groups, including the University of Hawaii at Hilo and the Friends of Liliuokalani, to remove the sludge from the pond have had little success.

“They have been collecting water samples for several years. … They’ve also had bimonthly groups that have been coming to remove the sludge, with no end in sight. And as we know, once in a while there’s some pretty putrid smells that are impacting the park users,” Osborne said during the committee meeting, adding that data suggests that nearby sewage leaks may be contaminating the pond.

The cleanup pilot project, “Project Genki Hou,” follows an ongoing effort to clean up the Ala Wai Canal on Oahu using the genki balls. The balls are made up of mud, rice bran and molasses, which make up a medium to house and feed yeast, lactic acid and phototrophic bacteria.

Thousands of the genki balls were thrown into the canal in April — although smaller “drops” at the canal have been done since 2019 — and the microorganisms in the balls have been removing sludge ever since.

Hiromichi Nago, technical adviser for the Ala Wai Canal efforts and among Hawaii’s leading authorities on genki ball cleanups, is assisting with the Hilo project.

He reported to the committee that the Ala Wai Canal’s water is cleaner, clearer and more oxygenated after being treated with the genki balls.

The microorganisms have digested and removed sludge buildup, Nago said, perhaps most dramatically at a site near Jefferson Elementary School, where a reported 23 inches of sludge was reduced to 5 inches between July 2021 and the end of May.

He showed photos and videos of fish and other animals, including turtles, in the canal.

In one instance, Nago showed photos of clear canal water five days after a storm and sewage spill in December.

“It’s just amazing how the microorganisms can help reverse all that (water) degradation,” he said during the committee meeting. “It’s cleaner than before the heavy rain, I think.”

Osborne requested $5,400 in Council member contingency funding for the cleanup project. The committee members showed overwhelming support for the project, and several committed funding for it.

The genki ball method, compared with techniques like dredging, has been hailed by its supporters as a cheap, environmentally friendly water cleanup method that’s also engaging to the public.

The timeline for treating Waihonu Pond is still being finalized, but Osborne said the first genki ball-making event will be on Nov. 5, and the first toss will take place Dec. 3. The second toss will be Dec. 23, she said. The final toss will take place on Earth Day, April 22.