Canada's drinking water can remain at risk long after wildfires burn out, according to a UBC-led global review that found water-quality impacts often emerge months or years later—not just immediately after a fire. Researchers analyzed 23 studies across 28 watersheds worldwide, comparing pre- and post-fire levels of sediment, nutrients, metals, organic carbon, ions and wildfire-fighting chemicals. Across climates, contamination often intensified over time, particularly when storms or snowmelt washed stored ash and debris into rivers.
