The Grand Canyon’s Water is Supposed to be Pristine. Scientists Just Found Pharmaceuticals in It

This news story describes how scientists have detected traces of pharmaceutical drugs and so-called ‘forever chemicals’ in water emerging from springs near the Grand Canyon’s South Rim, challenging assumptions that the area’s waterways are pristine. Carried out by the U.S. Geological Survey and the National Park Service, the study found contaminants of emerging concern (CECs) in locations including Bright Angel Wash, Monument Spring, and Upper Horn Bedrock Spring. One spring feeding into the Colorado River contained measurable amounts of several medications, such as an antibiotic, antifungal, antidepressant, anticonvulsant, and a diabetes drug.

While the detected levels do not exceed current drinking-water standards, many of the substances have no regulatory limits, making it difficult to judge their safety. Researchers believe the contamination likely comes from treated wastewater seeping from the South Rim Wastewater Treatment Plant into groundwater and returning to the canyon via the Bright Angel Fault.

In addition to pharmaceuticals, the study also identified PFAS chemicals, which persist in the environment and are linked to health risks including hormone disruption, cancer, and infertility. Environmental advocates warn that even low concentrations of these substances could harm sensitive wildlife that depend on the springs, such as frogs and salamanders, and raise concerns for backcountry visitors.

To read how drug industry pollution is increasingly affecting global food chains, water supplies, and the environment, see this article on our website.