Bigger and More-Frequent Wildfires Threaten US Water Supplies, With Contamination Lasting Years, Studies Show
Wildfires leave behind charred trees and scorched vegetation that impact the streams and rivers providing drinking water to much of the United States, and new studies show that contamination could remain for more than a decade, the Associated Press reported on November 13. So far in 2026, there have been 68,179 blazes in the United States, burning more than 9.5 million acres.
A University of Colorado Boulder study assessed wildfire-affected water quality in hundreds of burned basins and compared them with unburned areas. Carli Brucker, the study's lead author, said forested watersheds provide water to nearly two-thirds of municipalities in the United States, and that the impacts on water quality can last up to eight years.
Amanda Hohner, an assistant professor at Montana State University who specializes in wildfires and water quality, said wildfires are a natural part of forest ecosystems, but an increase in their severity has made watersheds, the areas that capture, filter and regulate the flow of water, vulnerable.
Garrett McKay, an associate professor of civil and environmental engineering at Texas A&M University, said utilities are extremely concerned about the impacts wildfires have on water. Sediment washed from burned landscapes is a headache for water-treatment plants, which usually rely on natural filtration and are not equipped to handle the increased levels of heavy metals and organic matter after a wildfire, leading at times to temporary shutdowns and a search for alternative water sources. Reservoirs can act as sedimentation basins but become prone to nutrient-rich sediment build-up that can cause harmful algal blooms.
Las Vegas, New Mexico, is still recovering four years after a fire, the report noted.
Source: Associated Press
Published by GSM · USA (original Chinese edition)
Photo: 图：野火在山地燃烧、浓烟升起（资料图）。Region 5 Photography 摄，公共领域，经 Wikimedia Commons。 / Photo: A wildfire burning in mountain terrain (file photo). By Region 5 Photography, public domain, via Wikimedia Commons.
