CAREER: The Microbiology of Climate Change Disasters: Microbiome-Contaminant Interactions After Wildland-Urban Interface Fires

Wildfires are causing significant destruction in the United States and worldwide including damages to drinking water systems at the wildland-urban interface (WUI) where humans and their built environment meet and interact with wildland vegetation. During WUI wildfires, the plastic components of drinking water pipes and distribution networks can undergo combustion and pyrolysis with a subsequent release of toxic volatile organic chemicals (VOCs) such as benzene, toluene, styrene, and vinyl chloride that can contaminate drinking water and promote the growth of microorganisms in drinking water distribution systems (DWDS) including harmful pathogens.

This poses new concerns about drinking water quality and safety following wildfires that have not been addressed in previous studies. The overarching goal of this CAREER proposal is to investigate the impacts of VOCs released following WUI fires on the drinking water microbiome and water quality in DWDS. To advance this goal, the Principal Investigator proposes to evaluate the hypothesis that 1) the release and continued presence of high concentrations of VOCs in DWDS following wildfires will consume the residual disinfectant in these systems and 2) the remaining VOCs will be metabolized to support the growth of microorganisms present in tap water including water-borne pathogens such as Legionella spp.

The successful completion of this project will benefit society through the generation of new fundamental knowledge to support the design, development, and implementation of solutions to mitigate and minimize the impact of WUI fires on drinking water quality and safety. Additional benefits to society will be achieved through student education and training including the mentoring of one graduate student and one undergraduate student at the University of California, Irvine.

As wildfires become more frequent and severe in the United States and worldwide due to climate change, there is an urgent and critical need for new fundamental knowledge to understand and mitigate the adverse impact of wildfires on drinking water quality and distribution systems at the wildland-urban interface (WUI). Recent studies have established that the combustion, pyrolysis, and thermal degradation of plastic infrastructure during WUI wildfires release high concentrations of toxic VOCs (e.g., benzene, vinyl chloride) that will continue to contaminate drinking water distribution systems (DWDS) and tap water for several months following these fires.

In addition, the released VOCs will consume the residual disinfectant in DWDS, and the remaining VOCs can be metabolized by microorganisms present in tap water, including pathogens that have genetic potential for VOC degradation such as Legionella spp. This CAREER project will evaluate the impact of VOCs released following WUI fires on the drinking water microbiome and tap water quality in DWDS.

The specific objectives of the research are to 1) investigate the effect and impact of environmental factors (e.g., drinking water source composition and residual disinfectant/VOC concentrations) and flushing protocols (e.g., stagnation and sequential flushing) on microbial growth in DWDS and tap water following WUI fires; 2) evaluate the role of biofilms in mediating VOC sorption and microbial transformations in DWDS and tap water after WUI fires; and 3) use and leverage multi omics (genomics and metabolomics) to characterize and unravel changes in the structure and function of microbiomes in DWDS and tap water following WUI fires. The successful completion of this project has the potential for transformative impact through the generation of new fundamental knowledge to advance the design and development of solutions to mitigate and minimize the impact of WUI fires on drinking water quality and safety.

To implement the educational and outreach activities of this CAREER project, the Principal Investigator (PI) proposes to leverage existing programs and resources at the University of California, Irvine (UCI) to develop English/Spanish bilingual environmental/climate change curricula in partnership with a statewide K-12 teacher network. In addition, the PI proposes to 1) partner with local artists and researchers to co-create a community science project on tap water quality and 2) integrate the research findings from this CAREER project into existing UCI courses devoted to Bioremediation and Microorganisms and Climate Change.

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.