In August 2023, communities in western Maui, Hawaii, were devastated by the deadliest U.S. wildfires in more than 100 years. The fires burned more than 6,700 acres; destroyed thousands of homes, community buildings, and historic cultural sites; and killed at least 102 people.
In the days after the fires, Maui County declared a precautionary unsafe water alert, and officials began testing municipal and residential water supplies for contamination. In partnership with community members, researchers began conducting supplementary water tests, aiming to understand how contamination varied throughout the burned area and over time and to share those findings with Maui’s residents.
The project detected some volatile organic compounds (VOCs) and disinfection by-products in a few mains, service lines, and home water samples, though the contamination was not widespread. The project demonstrated how partnerships between scientists and affected populations can reveal lingering wildfire impacts and empower communities as they rebuild.
After a disaster, “there’s sometimes a hard line between ‘us and them,’ or ‘government agencies and people needing help,’” said Liza McLatchy, a geospatial research engineer at the University of Hawai‘i at Mānoa’s Water Resources Research Center. “What we’re focusing on is where universities can fill that gap and provide that support.”
Building Trust
Wildfires can damage water infrastructure by melting plastic pipes and components, depressurizing the water distribution system, and contaminating source waters with ash, soot, or surface runoff from firefighting, explained Erica Fischer, a civil engineer at Oregon State University in Corvallis who was not involved with the Maui project.
Damaged water infrastructure can worsen water quality, introducing contaminants like volatile and semivolatile organic compounds (SVOCs), heavy metals, fire-suppressing compounds, and disinfection by-products. If a system doesn’t use plastic pipes, depressurization is usually the primary source of water contamination.
“When the fire service is putting high demands on the water distribution system at the same time that homes have burned down, communities have observed depressurization of the water distribution system,” Fischer explained. “Ash and soot that is sucked into the system contains VOCs, among other harmful contaminates. This ash and soot sticks to the interior of the pipes, gaskets, and valves and takes multiple flushing attempts to remove.”
Regulatory agencies tested water quality throughout burned areas, looking for VOCs and SVOCs like benzene, toluene, styrene, methylene chloride, and other contaminants regulated under the Clean Water Act. These chemicals can affect liver, kidney, and circulatory function and increase the risk of cancer.
The team of hydrologists and engineers, some of whom live on Maui and are members of the affected communities, tried to find the right way to contribute their expertise in the wake of the disaster. They began gathering water samples with the supplies they had on hand in their labs, hoping to enhance the water testing already being done by government agencies, said Christopher Shuler, a hydrologist also at the University of Hawai‘i at Mānoa’s Water Resources Research Center.
“It just sprung up from the community, spending time with people, seeing what was going on on Instagram,” said Shuler. “We just one day decided to go out and start taking some samples, and then we built that into a testing pipeline.”
Some homeowners distrusted government disaster response teams from U.S. EPA and the Federal Emergency Management Agency (FEMA) because of misinformation or past government mistreatment. That distrust hindered some of the agencies’ in-home sampling efforts, communication, and outreach.
The researchers felt that they themselves could respond to those needs. They hired new staff from the affected communities to conduct widespread sampling.
“Maui is a small community,” Shuler said. “We knew the importance in interacting with homeowners under stress, of having somebody that people knew and trusted going into people’s homes, a very sensitive space, especially after this trauma.”
Community members began recognizing the sampling team, inviting them into their homes or recommending them to their neighbors. Knowledge of the project spread by word of mouth and text groups.
“There’s a lot of trust [needed in] letting someone into your home,” McLatchy said. That community buy-in was invaluable in earning the trust needed to gather in-home samples.
Informing Communities
When invited by residents, the team tested for 78 VOCs from indoor faucets and outdoor spigots. Most of their sampling requests came from people who were about to or had already moved back home, so the houses’ water supplies had already been tested and cleared by regulatory agencies.
“These water samples are in no way meant to replace what needs to be collected by government agencies and are not able to tell residents if their water is safe through a qualified test,” Fischer pointed out.
The researchers found few cases in which residents’ water supply contained VOCs that agency testing had missed. Most VOCs they detected came from burned-down or unoccupied structures adjacent to livable houses, Shuler said.
“What surprised community members through our data and especially in tap water samples was the concentration of disinfectant by-products,” McLatchy said. Disinfectants are commonly used to treat drinking water, and the researchers expected to find their by-products.
“But we saw shock from homeowners because that kind of information was not easily shared,” McLatchy said. “We were able to step in and explain where that was coming from, explain that this was not fire-related…and provide some guidance of maybe investing in a home filtration system.”
As they analyzed samples from across Maui, the team put together a community information portal with an interactive map to share their results with people affected by the wildfires. The results of the project will be presented on 12 December at AGU’s Annual Meeting 2024 in Washington, D.C.
Empowering Recovery
Johanna Blake, a hydrologist and geochemist at the U.S. Geological Survey’s New Mexico Water Science Center, said, “The work being done by this group is very important. The urban-wildland interface during wildfires is becoming increasingly important to study and understand.”
“Projects like these complement government water quality testing, as the government may not be testing for VOCs or other potentially harmful analytes,” added Blake, who was not involved with this research. “Providing water quality information to communities helps them be better prepared for postfire recovery by identifying water quality issues in as many ways as possible.”
The team is continuing to analyze the results of their water quality sampling to better understand how VOCs are distributed through a burned area and how that distribution changes over time.
“The type of work that the research team has performed is critical to better understanding the mechanistic behavior of VOC and SVOC contamination within communities due to fires,” Fischer said. “Once we can fundamentally understand that, we will be able to determine where vulnerabilities are within communities and how they can mitigate against this occurring, or prepare for it for when it happens. That is ultimately how we can empower communities to mitigate against this secondary hazard.”
—Kimberly M. S. Cartier (@AstroKimCartier), Staff Writer
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Citation: Cartier, K. M. S. (2024), Water testing builds trust in science as Maui communities recover, Eos, 105, https://doi.org/10.1029/2024EO240562. Published on 12 December 2024.
Text © 2024. The authors. CC BY-NC-ND 3.0
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