Glacial Transport of Human Waste and Survival of Fecal Bacteria on Mt. McKinley’s Kahiltna Glacier, Denali National Park, Alaska

Abstract

Each year, over 1000 climbers attempt an ascent of Mt. McKinley via the West Buttress, located on the 77-km-long Kahiltna Glacier in Denali National Park and Preserve, Alaska. Climbers generate over two metric tons of human waste annually, the majority of which is disposed of in crevasses. To assess potential health impacts of this management practice, we conducted field studies and a laboratory experiment to document the persistence of fecal bacteria in a variety of glacial microclimates. Low concentrations of fecal bacteria found in water samples collected over two melt seasons from the Kahiltna River support the argument that bacteria can survive in a glacial environment for an extended period of time. We documented Kahiltna Glacier surface velocities and used a simple flow model to predict the time and place that human waste will emerge in the ablation zone. Based on surface velocities we predict that waste buried in major camps will emerge at the glacier surface in as little as 71 years after traveling 28 km downstream. Our results show fecal microorganisms are persistent in a glacial environment, these pathogens pose a minor threat to human health, and buried human waste can be expected to emerge at the glacier surface within decades.