Study from UH Hilo Detects Sewage Contamination Along Hilo Coastline

A study conducted by the University of Hawaii at Hilo has revealed sewage pollution at various coastal locations between Keaukaha and Honolii. The research involved monthly sampling at 16 sites from 2020 to 2022 to identify bacteria associated with fecal contamination, as well as nutrients and chemical indicators to trace the sources of wastewater. Although wastewater was detected at all sampled locations, the levels of pollution were generally low.

Researchers highlighted that fresh groundwater entering the ocean diluted some contamination signals, complicating detection through standard water testing. By integrating water analysis with the density of nearby cesspools, the team identified key pollution hotspots, particularly from King’s Landing to Honolii Beach Park. The findings indicated that wastewater contributed to 8% to 49% of nitrate levels in various locations, reinforcing the need to address cesspools not only near the shoreline but also by rivers and streams.