At K. V. Muniraju’s farm near Vijayapura, a city in Karnataka, India, raw sewage pumped from a cesspool flows onto crops in this image from July 2017. Photo © J. Carl Ganter/Circle of Blue

Global Rundown

  • To address global chemical pollution of water, air, and soils, the United Nations has announced the formation of a new Intergovernmental Science-Policy Panel.
  • A new study identifies naturally occurring uranium contamination as a widespread issue in the groundwater supply in Eastern Karnataka, India. 
  • Mountain communities in Venezuela, the first tropical country to lose all its glaciers, are adapting to their ice-less reality. 
  • Following wildfire, the water quality of nearby streams, rivers, and lakes in western U.S. watersheds tends to worsen for years, new research suggests.

The Lead

After wildfires burn in the western United States, the water quality of nearby streams, rivers, and lakes worsens — and often remains poor for longer than originally thought — according to a new study published last week in the journal Nature Communications Earth & Environment.

The study, led by researchers at the University of Colorado Boulder, found that “contaminants like organic carbon, phosphorus, nitrogen, and sediment can degrade water quality for up to eight years after a fire.” The scientists explain that unburned forests, lush with vegetation, serve as natural sponges and filters for rainwater when it falls. Trees, plants, and soils soak up water, limiting runoff. But fire consumes vegetation and cooks soils, making the ground hydrophilic. Rainfall after a burn moves quickly across the forest floor, collecting ash, sediment, and other contaminants and organic matter and depositing them into fresh water bodies, where they have lasting effects on water quality. 

To conduct their research, the scientists analyzed more than 100,000 water samples across 500 burned and unburned watersheds. They found that concentrations of organic carbon and phosphorus are usually elevated in the first five years following a fire, and higher levels of nitrogen and sediment appear up to eight years later. But there was also great variability. Some streams never showed significant increases in sediment, while others contained 2,000 times their usual amount. 

In last week’s Stream newsletter, Minnesota Public Radio reported that this spring’s wildfires in northern Minnesota have officials concerned about the long-term health of regional lakes, which are more likely now to be filled with sediment and have lower oxygen levels, increasing the likelihood of algal blooms.

The University of Colorado Boulder research team hopes the study will help water managers and conservation agencies make more strategic plans for water resilience after wildfires.

In context: Billions in Federal Assistance after New Mexico’s Largest Wildfire. But Little Money to Repair Streams

Recent WaterNews from Circle of Blue

This Week’s Top Water Stories, Told In Numbers

66

Percent by which global deaths from modern forms of pollution have risen over the past two decades, according to the United Nations. More than 6.5 million people die each year as a result of air pollution alone, and roughly 1 million people succumb to diarrhea as a result of unsafe drinking water, sanitation, and hand hygiene, the World Health Organization reports. These figures project negatively, as the world’s generation of solid waste is expected to rise from 2.1 billion metric tons in 2023, to 3.8 billion metric tons in 2050. To better assess the health impacts of widespread contamination, the United Nations Environmental Programme announced last week that it would be creating a new Intergovernmental Science-Policy Panel on Chemicals, Waste and Pollution, prioritizing chemical pollution of air, water, and soil. The panel joins the Intergovernmental Panel on Climate Change (IPCC) and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) to form a “global scientific trifecta” dedicated to studying and limiting harmful man-made environmental change.

In context: Costs of Water Pollution, a Global Scourge, ‘Underestimated and Underappreciated’

78

Percent of tested groundwater sites in Eastern Karnataka, India, that exceed safe limits for uranium, according to a new study published in the journal Environmental Science and Technology. Led by researchers from Columbia University, the study found that uranium becomes “dangerously mobile in specific underground environments,” and in some locations was concentrated to levels 75 times the U.S. EPA limit — a finding that drew particular attention, as more than 70 percent of the Karnataka region’s 25 million people rely on groundwater for their drinking water. The researchers say the study is also applicable to regions in the American West and Midwest, where naturally occurring uranium is also a concern. 

On the Radar

In 2023, Venezuela’s last standing glacier, La Corona, was reclassified as an icefield after shrinking “to the size of barely two football fields,” Mongabay reports. Warming temperatures and a lack of precipitation have combined to make Venezuela the first tropical nation to lose all its glaciers, a reality that the city of Mérida, once known as “the city of eternal snow,” has been forced to confront both scientifically and culturally. Replacing ice, new alpine ecosystems are taking hold. Lichen and moss, with many species undetected before in Venezuela and some completely new to science, continue to emerge. Vascular plants, hummingbirds, bees, and flies highlight a “surprisingly small biological network” of seed dispersal and pollination. In recent years, as the slopes warm, farmers have been able to successfully harvest lemons, pears, figs, and sugarcane in developing soils. Meanwhile, a tourism industry previously dominated by skiing and ice climbing expeditions has now been replaced by rock climbing. 

Fresh: From the Great Lakes Region

Oak Creek Power Plant: We Energies, the company that operates the Milwaukee-area power plant on the shores of Lake Michigan, will keep two coal-fired units operating one year longer than originally planned, Wisconsin Public Radio reports. The units, built in the 1960s, will now be retired at the end of 2026 in order to meet immediate electricity demands. Environmental advocates say the continuation slows progress to address regional climate change, and will also increase costs for energy consumers.

Ohio’s Orphan Wells: A new report from the U.S. Geological Survey highlighting where orphaned gas and oil wells are the biggest threat to groundwater indicates that Ohio — where more than 20,000 documented wells exist — is particularly high-risk. Ideastream Public Radio reports that “about half of the country’s documented orphan wells are in aquifers that supply over 90 percent of the water we consume.”

Bridge Michigan, Circle of Blue, Great Lakes Now at Detroit Public Television, Michigan Public and The Narwhal work together to report on the most pressing threats to the Great Lakes region’s water. This independent journalism is supported by the Charles Stewart Mott Foundation. Find all the work here.

  • How Ontario could have cracked down on Chemical Valley pollution — but chose not to — The Narwhal
  • New report shows PFAS contamination in 98% of waterways tested — Great Lakes Now
  • US Supreme Court to consider Line 5 lawsuit jurisdiction case — Michigan Public
  • Iconic whitefish on edge of collapse as Great Lakes biodiversity crisis deepens — Bridge Michigan

Christian Thorsberg is an environmental writer from Chicago. He is passionate about climate and cultural phenomena that often appear slow or invisible, and he examines these themes in his journalism, poetry, and fiction.