Congratulations to Dr. Xiaolong "Leo" Geng for leading and winning a U.S. National Science Foundation (NSF) Standard Grant award for his proposal, "Hydrogeologic Controls on the Accumulation, Transport, and Discharge of Fecal Indicator Bacteria in Coastal Beaches." The project presents a comprehensive approach that combines state-of-the-art surface water, groundwater, and reactive transport modeling, along with field measurements. This three-year, $550K award will provide training opportunities for both graduate and undergraduate students to gain hands-on expertise in fieldwork, laboratory experiments, and numerical modeling.
Read the story on UH News
Sample collection at Oʻahu beach.
The National Science Foundation has awarded the University of Hawaiʻi at Mānoa a three-year, $549,960 grant to conduct fieldwork and groundwater sampling at two beaches in Hawaiʻi. “Hydrogeologic Controls on the Accumulation, Transport, and Discharge of Fecal Indicator Bacteria in Coastal Beaches” is a public impact research project to improve our ability to predict and manage water quality risks in Hawaiʻi’s coastal zones.
Coastal beaches are vital for recreation, tourism, and ecosystem health; however, they are increasingly threatened by fecal contaminants. These fecal bacteria can enter beach environments through human wastewater, stormwater runoff, and animal waste, accumulating in the sand and shallow groundwater. Natural coastal processes, such as tides and waves, can then mobilize and transport these contaminants across the land–sea boundary, posing risks to both public health and marine ecosystems.
This project will investigate how coastal hydrologic forces, including tidal fluctuations and wave action, influence the accumulation, movement, and discharge of fecal contaminants in beach aquifers. The research team will conduct fieldwork and groundwater sampling at two beaches in Hawaiʻi, where fecal contamination is known to occur, and will develop advanced computer models to simulate how bacteria move through beach sediments. The findings will improve our ability to predict and manage water quality risks in coastal zones.
Enterococcus concentrations measured at O‘ahu beaches in Co-PI Tao Yan's prior work, showing consistently high levels of fecal contamination at study sites, alongside their foreshore conditions.
Xiaolong “Leo” Geng, the project’s principal investigator and assistant professor at UH’s Water Resources Research Center and Department of Earth Sciences, will direct the project activities and supervise graduate and undergraduate students hired by this project.
According to Geng, “Beaches are at the heart of Hawaiʻi’s culture, economy, and ecosystems, yet they are increasingly vulnerable to fecal contamination. Our research will shed light on how bacteria move through sand and groundwater, helping to safeguard public health and marine environments. Just as importantly, we hope to inspire the next generation of scientists and strengthen community stewardship of our coastal waters.”
Geng’s co-principal investigator is Tao Yan, Water Resources Research Center director.
Student and Community Outreach
Broader benefits of the project include training two graduate students and engaging undergraduate students through the University of Hawaiʻi at Mānoa’s Undergraduate Research Opportunities Program (UROP). The team also plans to involve local communities through educational outreach and citizen science activities to support long-term coastal water stewardship in Hawaiʻi.