$5M NSF award to address outdated wastewater infrastructure

University of Hawaiʻi at Mānoa researchers are part of a team that was recently awarded a three-year, $5 million grant from the National Science Foundation to address the environmental and public health impacts of outdated wastewater infrastructure in island communities.

The project is led by the University of South Florida, with UH Mānoa playing a key role in research and pilot testing.

Focus on Hawaiʻi’s water health

In Hawaiʻi alone, an estimated 83,000 cesspools discharge approximately 52 million gallons of untreated wastewater into the ground each day, contaminating coastal waters and damaging coral reefs. Replacing cesspools with approved wastewater systems could cost households $30,000 to $50,000.

The Honu Hub project seeks to ease that burden by developing a solar-powered, compact and certifiable alternative that protects both human health and the environment. These systems are energy-independent and equipped with remote monitoring and automation, making them suitable for cesspool replacement in low-density and isolated areas. The “Honu Hub” represents a new class of small, adaptive and decentralized wastewater infrastructure.

By centering the work in Hawaiʻi, the research team ensures the technology is designed to overcome local challenges, including poor soils, high water tables and saltwater intrusion. The goal is to create a solution that can be adopted throughout the US Pacific region and the continental US.

UH Mānoa researchers are leading the design and real-world pilot demonstration of nutrient capture systems within the Honu Hub. Pilot testing is taking place at the Wahiawā Wastewater Treatment Plant, in collaboration with the City and County of Honolulu.

The award supports the Honu project within NSF’s Convergence Accelerator program, which aims to develop adaptive, decentralized wastewater infrastructure solutions for island and rural communities facing severe sanitation challenges.

Zhiyue Wang, the project’s co-principal investigator and assistant professor at UH Mānoa’s Water Resources Research Center and Department of Civil, Environmental and Construction Engineering in the College of Engineering, will assist with the pilot testing of Honu Hub in Hawaiʻi and developing novel technologies for nutrient recovery in the system.

“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,” Wang said.

Tao Yan, director of the Water Resources Research Center, is also part of the Honu research team. Wang is working alongside principal investigator Daniel Yeh (University of South Florida), co-principal investigator Stuart Coleman (Wastewater Alternatives and Innovations) and co-principal investigator Allan Smith (Swiftwater Solutions).