Wildfire aftermath: Contaminated drinking water
Wildfires do not just wreak immediate havoc and destruction — they also have a toxic aftermath, especially affecting drinking water systems. In the Western United States, recent conflagrations have reaffirmed the urgent need to issue post-fire drinking water warnings and to find and remove contaminants in utility and building plumbing systems.
The grass fire that broke out in Boulder County, Colorado, in 2021 — dubbed the Marshall Fire, as it originated on Marshall Road — destroyed more than 1,300 homes and caused $2 billion in damage during a two-day rampage. This became the most destructive wildfire in Colorado’s history. More than 40,000 people were impacted, and received their drinking water from damaged public water systems and private wells.
Just days after the fire was extinguished, community leaders reached out to our team asking for assistance, suspecting that their water systems may have been contaminated and posed immediate health threats.
Like with disasters before, we traveled to the site and provided scientific support to owners of damaged public water systems, private well owners, and government officials. Our team helps guide communities on how to rapidly find contamination, communicate warnings, and inform strategies for returning damaged systems to safe use.
By considering our input, two water utilities affected found chemical contamination. These discoveries represent the first time such contamination has been found after a wildfire in Colorado — with the state joining California and Oregon in the years since 2017.
To help the local health department, we also conducted private drinking water well testing. Through our results, we discovered some wells had become contaminated with debris. Equipped with our testing results, county and state health departments were able to issue water safety guidance to well owners.
This support was made possible because municipal leaders reached out to us and, in early 2022, we were awarded a National Science Foundation Rapid Response Research (RAPID) grant. Through federal support, we have been working to understand how fire impacts infrastructure — like damaged utility pipes, gaskets, meters, and plumbing components. During our rapid response, officials were integrating our preliminary results to make recovery decisions.
As communities across the nation experience wildfires, we also are investigating whether plastic drinking-water distribution system components are partly responsible for causing and prolonging the water contamination. Thermally damaged plastics like pipes, gaskets, meters and other devices can fail mechanically, but sometimes they are heat-damaged and do not leak. In 2021, we discovered that thermal exposure can prompt the plastic water system materials to generate chemicals at levels that pose an immediate health risk to water users. Our findings were confirmed by the state of California’s 2022 follow-up study (much of this work was catalyzed by discoveries after the 2017 and 2018 wildfires in California).
Through our ongoing research, we also are exploring how the additives present in the plastics influence the contamination caused by the plastics. Ultimately, our learnings may enable product manufacturers to innovate new materials less likely to cause contamination. Code officials and utility managers also could recognize the effects of different damage scenarios, informing construction decisions to better protect those assets.
An important aspect of our Engineering experience enables students to directly investigate complex issues and share their new knowledge with those who need it most — homeowners, agencies and companies impacted. Through these opportunities, students acquire practical, firsthand knowledge, and they work as partners to support social, environmental and economic sustainability.
Wildfires have emerged as regular, destructive, and sometimes fatal forces across the United States. To address the health and economic risks posed by wildfires, we must improve building codes that lessen the damage and chance contamination that may occur. When wildfires damage water systems, contamination must be rapidly found and removed. As we continue to help communities and companies nationwide, our discoveries and guidance can be found here.
Andrew J. Whelton, PhD
Professor of Civil Engineering and Environmental and Ecological Engineering
Director of the Center for Plumbing Safety
College of Engineering