RAPID: Understanding the Immediate and Long-Term Impacts of Maui Wildfires on Chemical and Microbiological Quality of Nearshore Beach and Coastal Waters

On August 8, 2023, a rapid and devastating wildfire burned through the historical town of Lahaina (Maui) in the State of Hawaii. Early indications suggest that the Maui wildfire caused the release of hazardous chemicals and pollutants into the environment including 1) volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and heavy metals from the burning of vegetation, vehicles, and structures and 2) nutrients (nitrogen and phosphate) and microbial pathogens from untreated wastewater released following power outages and disruptions of the operations of local wastewater treatment plants.

This RAPID project will evaluate the impact of these hazardous chemicals and pollutants on chemical and microbiological water quality in the local coastal/beach aquifers and ecosystems following the Maui wildfire. To advance this goal, the project team will collect and analyze sediments, surface water, and groundwater samples from areas affected and unaffected by the wildfire.

In addition, the project team proposes to combine the on-site measurements with groundwater modeling to characterize and identify the extent and mechanisms of contaminant transport across the land-sea boundary in coastal areas that are affected by the wildfire. The successful completion of this project will benefit society through the generation of data and fundamental knowledge about the immediate and long-term impacts of the Maui wildfire on chemical and microbiological water quality in coastal/beach aquifers and marine ecosystems.

Such new data and knowledge would be critically needed to guide water resource managers, local communities, and other stakeholders in Maui as they design and implement solutions to mitigate the contamination of local drinking water sources and improve the resilience of coastal/beach aquifers and ecosystems to contamination following wildfires. Additional benefits to society will be achieved through student education and training, including the mentoring of two graduate students at the University of Hawaii at Manoa.

Following the Maui wildfire, a broad range of hazardous chemicals such as volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and heavy metals, as well as nutrients such as nitrogen and phosphorus, were released into the environment including the vadose zones of costal and beach aquifers. These contaminants pose both immediate and long-term threats to coastal water resources in Maui through surface runoff (rapid and acute) and submarine groundwater discharge (slow and chronic).

The overarching goal of this RAPID project is to investigate this dual mechanism of contaminant transport and its adverse impacts on local drinking water sources and coastal/beach aquifers and ecosystems in Maui. The specific objectives of this research are to 1) evaluate the immediate impact of the wildfire on chemical and microbiological water quality in local beach and coastal aquifers, 2) probe the long-term impacts on chemical and microbiological quality of groundwater within beaches in Maui and 3) characterize the extent and mechanisms of contaminant exchange and transport across the interface of the sea and beach over multiple time scales, driven by tide- and wave-induced interactions between seawater and groundwater.

The successful completion of this project has the potential to advance the fundamental understanding of the fate and transport of contaminants released following wildfires in coastal regions and their adverse impact on local water resources and marine ecosystems. To implement the educational and training goals of this RAPID project, the Principal Investigators propose to leverage the University of Hawaii at Manoa Undergraduate Research Opportunities Program to engage and recruit undergraduate students from Maui to work on the project research activities.

This RAPID project is jointly supported by the ENG/CBET Environmental Engineering and Environmental Sustainability programs.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.