Water resources

Three-foot high wooden walls enclose a small plot of soil and plants.

When the Unmentionable becomes Unavoidable

Wastewater is a fact of life we tend to shy away from. But with sea-level rise compromising many coastal cesspools, attention (and legislation) has focused on the larger cesspool issue in Hawaiʻi. Read more about our 2020 Grau Fellow’s experience working on this unmentionable problem.
flying drone

Wai, from mauka to makai

New technology can to help detect hidden waters that carry unwanted contaminants into Kāneʻohe Bay, according to Michael Mathioudakis. Come read about his efforts to help trace submarine groundwater discharge as one part of managing Hawaiʻi’s critical coastal resources.
A water hazard sign sits near a beach

Tracking groundwater nutrients using novel tracers to inform coastal watershed management in South Kohala, Hawaiʻi

PI: Henrietta Dulai
Using a combination of nitrogen isotopes and microcontaminants as source tracers, this project aims to identify pathways of groundwater flow to the coastline along South Kohala, Hawaiʻi, tracing sources of groundwater contaminants and excess nutrients. Managers can use results to improve wastewater management and improve coral reef resilience.
A split image with the left showing a researcher adding dye to the top of a cesspool, and the right showing a natural rock-enclosed pool dyed green.

Identifying hot spots of sewage pollution in Hilo, Hawaiʻi

PI: Tracy Wiegner
Hawaiʻi banned new cesspools in 2015, but groundwater contamination from the remaining 8700 cesspools in the Hilo area is a continuing concern. This work will use dye tracer studies to track cesspool outflows and use sewage indicators to establish contaminant sources to coastal groundwaters to inform future management decisions.
On a rocky shoreline, one student crouches next to a bucket while another stands ready to write on a clipboard

Differentiating treated and untreated wastewater contamination in a tropical coastal community using microbial community genomics

PI: Craig Nelson
There is growing concern that coastal ecosystems are threatened by sewage contamination of groundwaters. Using genomic methods, this project will examine the bacterial populations in the Keaukaha area of Hawaiʻi Island, to differentiate sources of contamination, and aid in management efforts to ameliorate sewage leakage.
Map view of coastline with super-composed thermal data showing locations of groundwater entry of ocean

Collaborative Study of Groundwater Transport Paths and Discharge Loads of Wastewaters and Other Land-Uses that Impact the Ewa Coastal Zones of West Oʻahu

PI: Craig Glenn
On-site sewage disposal systems threaten groundwater quality via the release of untreated sewage effluent to the environment. This work plans to use remote sensing techniques with field studies to establish groundwater flow paths and contaminant transport around Ewa Beach, Oʻahu, to aid in future remediation strategizing.