A novel wastewater treatment solution currently undergoing evaluation at the Wahiawā Wastewater Treatment Plant on Oʻahu could offer a crucial, cost-effective path forward as Hawaiʻi faces a massive statewide infrastructure overhaul.
The Hawaiʻi Onsite Wastewater Technology Evaluation Program (HOWTEP) was officially launched during the Wastewater Innovation Tech Showcase on August 26, at the Wahiawā Wastewater Treatment Plant.
Executed by the University of Hawaiʻi at Mānoa (WRRC), HOWTEP is a three-year pilot testing program funded by companion bills and . WRRC evaluates innovative systems and provides evaluation reports to the Hawaiʻi Department of Health to support their decision-making and certification process. This directly accelerates the commercialization and approval of affordable wastewater technologies.
The initiative advances accessible, decentralized wastewater solutions to help property owners meet the mandate requiring the replacement, conversion or closure of nearly 88,000 cesspools across the state by January 1, 2050. Beyond system certification, HOWTEP serves as a multi-purpose hub for WRRC to conduct research, offer hands-on student training and perform community outreach.
Honu Hub
Honu Hub, which is supported by a $5 million National Science Foundation grant, is the first technology to be evaluated under the HOWTEP platform. It is led by Assistant Professor Zhiyue Wang (WRRC and Department of Civil, Environmental and Construction Engineering), Professor and Director Tao Yan (WRRC and Department of Civil, Environmental and Construction Engineering) and Professor Daniel Yeh (University of South Florida).
Honu Hub is a decentralized wastewater treatment system designed to process sewage completely above ground. By packing its technology into a compact 52-square-foot space—roughly the size of a standard garden shed—the unit eliminates the need for expensive heavy machinery, extensive excavation and costly landscape restoration.
For many homeowners, replacing a cesspool with a conventional septic system costs between $30,000 and $50,000—a financial burden amplified by difficult terrain, high water tables and tight lot boundaries. Honu Hub was engineered as an affordable alternative designed to drastically lower these conversion costs.
“The WRRC team’s role in this is to help with research and development to improve the technology and study the fate and transport of emerging contaminants in this system,” Wang said.
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