This project employs measurements of groundwater chemistry and microbial tracers in water samples from across the Hualālai and Pearl Harbor aquifers to understand the source locations and flow paths of groundwater within the aquifers. This work can be used to address the extent of groundwater flow connectivity across geologic and geographic boundaries, ultimately enabling more robust water budget estimates and providing critical information for management of contamination issues.

This project uses information about coastal submarine groundwater discharge (SGD) to improve our understanding of the Hualālai aquifer water budget. Long-term SGD monitoring platforms document changes in groundwater discharge over time to improve understanding of SGD drivers, such as precipitation and groundwater withdrawal. Measurements of the chemical composition of coastal springs also help in reconstructing groundwater flow paths and the interconnectivity between aquifers.

This project aims to develop a sensor system that monitors well water quality with high temporal and spatial resolution. Measurements of details such as water level, temperature, and salinity will better support estimates of aquifer parameters, which can be used to quantify sustainable yield more accurately. Fluorescence detection will also enable monitoring of organic water contaminants, such as oil and bacteria, providing an opportunity to inform well owners promptly.

This portion of the geophysical project involves characterizing subsurface features in the Hualālai and Pearl Harbor aquifers using an assortment of low environmental-footprint geophysical techniques. The aim is to identify and investigate important aquifer elements such as flow-controlling geological structures, the water table, fresh- and salt-water interfaces, aquifer distribution and connectivity, flow paths, no-flow depth, and other hydrological parameters. This work has included active information sharing efforts with local landowners and organizations.

The marine geophysics component of this project will use a newly developed surface-towed marine electromagnetic (EM) system and 2D/3D inversion algorithms to study the spatial distribution and interconnectivity of the Hualalai groundwater system offshore the Kona coastline, the island of Hawai‘i. The surface-towed controlled-source EM (CSEM) data will be acquired to image the electrical resistivity structure of these submarine groundwater reserves, likely embedded within complex volcanic geology that includes buried dike, fault systems, and lava tubes.  See the blog for more details on this research.