The most deadly and destructive wildfire in California history spread metals into North State watersheds. A new study explains how the metals were dispersed and what that means for public health.
The paper offers a comprehensive look at what went into the local watersheds after the Camp Fire, and eventually flushed out in the following rains. It also analyzes the “bioavailability” of different metals, or the ease with which they are absorbed into the bodies of humans and other life forms.
The two Chico State professors who led the project began their research five years ago in November 2018.
One of them is Jackson Webster, associate professor of civil engineering. He says while the study did find metals in the water, most weren’t in a bioavailable form. That’s a relief for the fish and the humans who came into contact with the water.
“We spent all of that time just sampling, borrowing money, getting support wherever we could just to keep the effort going,”Jackson Webster, Chico State Associate Professor of Civil Engineering
“While the environment looks very bad in this kind of disaster area … that doesn't necessarily directly translate into a highly contaminated environment with these metals,” Webster said. “In some ways this is a positive outcome.”
For months after the Camp Fire, Webster and his collaborator, Sandrine Matiasek, from Chico State’s earth and environmental sciences department, made arduous, sometimes daring, trips to the burn scar to collect samples. When they began their work, the Camp Fire was still burning, quieting into a smolder as the winter rains began. On the streets of Paradise and Magalia sat pools of melted metals that used to be cars.
Webster even stole past the National Guard to collect water samples in the burn scar.
“I really wanted to get some samples from inside of Paradise, and so [I] may have forged a badge and driven through the security checkpoint with a fake badge,” he said.
Webster says they started collecting samples without funding or any certainty that their research would be supported. They just thought it was that important to collect those samples.
“We spent all of that time just sampling, borrowing money, getting support wherever we could just to keep the effort going,” Webster said.
That’s because one of the key data gaps in studies on wildfires is the “first flush,” the ash and stormwater that flows off the burned landscape during the first rains of the season. Scientists want to study the first flush to know what minerals and metals the fire has put into the water.
Before Matiasek and Webster’s research, few scientists had been able to sample a wildfire’s first flush. And no scholars had studied such a large wildfire in the wildland-urban interface. While other papers looked at wildfires burning up the natural landscape, the Camp Fire combusted nearly 20,000 houses and likely twice as many cars.
“The data just wasn't there,” Webster said. “What would happen to these watersheds, what [metals] would be transported?”
“I don't lose sleep over the outcome of the study, I don't find [it] to be something that the public should be alarmed about.”- Jackson Webster, Chico State Associate Professor of Civil Engineering
Another exciting piece of their new study: key data that another Chico State professor, David Brown, had collected 15 years ago.
“We had access to some metal concentrations [from 15 years ago] in some of the creeks that we studied,” Matiasek said.
Matiasek said it’s “extremely rare” for studies on wildfire and water to have data from before the fire as well as after the fire.
“Who has the foresight to know where the next fire is going to occur?” she said.
Thanks to Brown’s work, the researchers were able to compare their samples to data collected in those watersheds before the Camp Fire.
According to their findings, the metal concentrations in these watersheds were comparable to a dense urban environment like downtown Sacramento or downtown San Francisco. While it’s unusual to see that level of pollution near Paradise, Webster said it could have been worse.
“I don't lose sleep over the outcome of the study,” Webster said. “I don't find [it] to be something that the public should be alarmed about.”
He said people and governmental agencies should be relieved to know local watersheds weren’t subjected to highly toxic metal concentrations after the Camp Fire. At the outset of the study, that was his worry.
The study could have implications for the endangered salmon populations that come to spawn in some of the watersheds Matiasek and Webster studied. Metals can be highly toxic to fish, and in many instances, Matiasek and Webster found metal concentrations that exceeded the United States Environmental Protection Agency’s water quality criteria for aquatic life.
“Salmon are at the top of the food chain, and so it may take a while for metals to reach this level of the food chain and affect salmon,” Matiasek said. “At the same time, there are physical impacts, changes to the physical habitat, that can impact salmon populations right away.”
Salmon, once abundant in the region during the spawning season, returned in concerningly low numbers last summer. It’s a statewide phenomenon affecting several waterways, attributed to climate change and other factors.
It’s a problem that requires further research, like the work of one Chico State master’s student using this new research to study how metals from the Camp Fire may have affected the organisms salmon eat in local watersheds.
Matiasek and Webster hope their work together will help future researchers understand the level of harm of wildfire pollution in the water. And they want to motivate governmental agencies and environmental organizations to prevent further pollution in watersheds during wildfires. Matiasek says that could mean using tools like “wattles,” ribbons made of straw or jute that keep fire debris away from water.
For Matiasek, one of the most meaningful things about publishing the paper is giving the research back to the community that survived the fire.
“We were always met by community members who were very happy to help us and to let us collect water … lots of people asking, you know, please share your results with us when you have them,” she said.
Because 125 faculty and staff at Chico State lost their homes to the fire, Matiasek said studying the fire was challenging in personal ways, as well as professionally. She said she and Webster committed to the study because they wanted to help understand the impact of the fire on the community they lived in.
Now, five years later, that research has finally been published.
It’s the end of a project that Webster says took a lot of work and a lot of help from the community, much of it during an unfolding disaster.
“So this feels like a good closing of this loop,” Matiasek said.
