Over 20,000 pieces of trash removed from Yellowstone’s thermal pools in 2026: Could the visitors’ waste harm the hot springs into changing color?

The US Geological Survey has said that its staff have removed more than 20,000 pieces of garbage as of late September 2026, from the hydrothermal areas, or the thermal pools in the Yellowstone National Park. The waste was removed by workers specially trained in safe hydrothermal navigation.

With this year’s tally setting a record, they have released a full list of items recovered from the hot springs and geysers in the national park. These include 280 hats, 54 camera lens caps, 47 hair bands and 17 bikinis. There were also expensive items like five AirPods removed from the hydrothermal areas.

Along with the garbage, the team has also removed nearly 10,000 rocks and sticks from these areas. This has been done to prevent any such foreign material permanently harming or changing the features of the national park’s pools and geysers.

The trash could destroy the thermal pools around Yellowstone

The trash left accidentally or deliberately could cause significant harm to the national park. It could harm sensitive environments that have taken decades to form. The thermal features in the park run on a complex plumbing system. The trash or even natural rock and sticks may clog the plumbing, resulting in the water’s flow reducing.

Apart from the plumbing, the garbage could also alter the chemistry of thermal pools at Yellowstone. The plastic in warm waters may react and leach chemical or microplastics into the pools. This would severely impact the microbes in these thermal pools. These microorganisms are behind the pools’ iconic colours.

According to National Geographic, the microplastic could harm the metabolism and the life-sustaining activity of microorganisms that live through the sulfurous compound found in the Yellowstone volcano. The Sulfurihydrogenibium yellowstonense microbes form about 98% of the microbial population in parts of the national park

A thermal pool once changed color due to trash

A similar phenomenon was previously seen when the Morning Glory Pool, which was named after a blue flower, changed color. The pool, which used to be blue, turned multicolored in the 20th century with hues of orange and yellow. This was attributed to the various kinds of trash thrown in the pool by visitors.

According to the national park, the trash thrown in the pool cooled the water’s temperature. This allowed orange and yellow coloured bacteria to grow. The pool was later drained to return its former blue colour, however it never returned completely.

Visitors using thermal pools as wishing wells

According to Margery Price, a geologist with the National Park Service several tourists are encouraged by other tourists and tour guides use the thermal pools as wishing wells and toss coins in them.

The staff removed over $18 in coins from the hot springs, as they continue to remain a problem. The metal can also alter the pools’ chemistry and microorganisms. According to National Geographic the metal might encourage some microbes to produce oxygen. This would kill certain bacteria and shift the overall balance.

Over 4.5 million people visit the national park every year to set their sights on the hot springs.