UH researchers join $5M NSF Honu Hub to develop solar-powered cesspool alternative

University of Hawaiʻi at Mānoa researchers are part of Team Honu, a multi‑institution effort awarded a three‑year, $5 million grant from the U.S. National Science Foundation Convergence Accelerator program to develop the Honu Hub, a compact, solar‑powered, certifiable decentralized wastewater system intended as an alternative to cesspools. The project aims to move the technology from research prototype to a product that homeowners, engineers, and installers can trust.

The urgency of the work is stark in local terms. KITV reported there are about 83,000 cesspools statewide releasing an estimated 52 million gallons of untreated wastewater every day, and multiple outlets note that replacing a household cesspool with an approved wastewater system can cost between $30,000 and $50,000. Untreated wastewater is implicated in coastal water degradation and harm to coral reefs, making effective, affordable alternatives a public health and environmental priority.

Honu Hub will be solar‑powered and energy independent, with remote monitoring and automation designed for low‑density and isolated areas. The system is engineered to recycle wastewater for beneficial reuse and to remove nitrogen that pollutes waterways. University of Hawaiʻi at Mānoa researchers are leading the design and real‑world pilot demonstration of nutrient capture systems, while pilot testing will take place at the Wahiawā Wastewater Treatment Plant in collaboration with the City and County of Honolulu.

Zhiyue Wang, co‑principal investigator and assistant professor at UH Mānoa’s Water Resources Research Center and Department of Civil, Environmental and Construction Engineering, said, "Collaborating with the University of South Florida, our goal is to empower communities with solutions that protect public health, preserve our nearshore ecosystems and ensure clean water for future generations." Tao Yan, director of the Water Resources Research Center, is also part of the UH Mānoa team.

The project is led by Daniel Yeh, professor in the Department of Civil and Environmental Engineering at the University of South Florida. Yeh emphasized the team’s practical focus: "The passion of our team members is what drives this work forward. We want to deliver not just a product, but a foundation for the people who will build, operate, and benefit from it." Yeh added, "Our focus now is to make sure there’s a true problem‑solution fit. Too many academic technologies stay in the lab. This award is about proving value, achieving certification and delivering a product that homeowners, engineers, and installers can trust."

Team Honu builds on Phase One work that received $650,000 under NSF’s Future Water Systems track, where the team completed entrepreneurship and human‑centered design training and advanced from 16 teams to one of six teams selected for Phase Two funding. University of South Florida team members include Robert Bair and postdoctoral researcher Hsiang‑Yang (Gary) Shyu, who is integrating artificial intelligence and machine learning into system design and monitoring. Partners named on the project include WAI.org and SwiftWater Solutions, and the product lineage is described as "powered by NEWgenerator."

For Big Island County residents, a certified, lower‑cost, solar‑driven alternative could ease the financial burden on homeowners and reduce pollution pressures on nearshore reefs and fisheries. Over the next three years the team will pilot, validate, and pursue certification; success could mean wider adoption across the U.S. Pacific region and the mainland. Readers should watch for pilot results and local opportunities to learn how the Honu Hub might fit Hawaiʻi communities that face challenging soils, high water tables, and saltwater intrusion.