We know wildfires pollute the air we breathe—but a new study shows they can also pollute the water we drink.
Siyu Pan, assistant professor in NAU’s Department of Economics, Finance and Accounting, has been researching the impact of wildfires on drinking water quality since 2023. Last year, under a Joint Venture Agreement (JVA) from the U.S. Forest Service and along with her research team, she published a study about community water systems exposed to wildfires in the western United States that showed how vulnerable communities are more prone to wildfire exposure. Now, with the same JVA, she is looking at the social cost wildfires have on drinking water.
“Drinking water quality could be impacted by wildfires through various channels,” Pan said. “Some water gets polluted through sediments caused by wildfires that sink into the water. Other times, when wildfires burn a lot, they bring up old pollution from the soil, which we call legacy pollution, and that sinks into the water too. Air pollution caused by wildfires also has an impact on drinking water through the intrusion of smoke and soot into the water. Another way in which the water is impacted by fire is through changes in water and ambient temperatures during and after fires, which might overwhelm the water treatment process.”
The research also looked at how those impacts differ between communities with a higher poverty rate and those with a lower poverty rate. The results: The quality of drinking water after a wildfire is worse in areas where minorities and lower-income communities live.
“We know wildfires worsen drinking water quality, but different communities have different capacities for cleaning up their water,” Pan said. “They also have different initial environmental conditions; some are just more resilient to worsened drinking water quality. The implication is clear: the social cost of wildfire is larger than we thought—we need to consider the worsening of drinking water quality as an important part of the social cost of wildfires and how that burden is shared unequally among different communities.”
The JVA has allowed different disciplines to work together on the study. Pan said they are all trying to get a comprehensive picture of the physical and social ways in which water pollution can damage people and communities.
“This is a collaborative effort,” Pan said. “Economists are at the downstream, while at the upper stream, they had a lot of environmental engineers, chemists, statisticians and others working on understanding the physical part of this. We build on their research results by adding the human component to understand the physical impacts and the impacts on the community.”
The next step may be estimating a monetary value to wildfires’ impact on water quality. With the help of economic models and statistical tools, Pan is hopeful that her team’s work will help stakeholders gain a more comprehensive and in-depth understanding of the full costs that wildfires impose.
Mariana Laas | NAU Communications
(928) 523-5050 | mariana.laas@nau.edu