Should We Ski on Poop?
Drier winters mean more ski resorts are using treated wastewater to make snow. Here are the dirty details.
Apr 01, 2025
About a decade and a half ago, a court case started a contentious debate that, in many ways, portends the future of ski resorts across the country. The Hopi Tribe sued Arizona Snowbowl in Central Arizona because the resort, which operates on a mountain sacred to the tribe in the San Francisco peaks of northern Arizona, had signed a contract to begin using treated wastewater to make snow on the mountain.
Wastewater, before treatment, contains human feces and urine, along with loads of other things you wouldn’t want to be within a few hundred feet of, much less skiing on. The tribe alleged the move would harm its cultural and ceremonial use of the mountain, as well as create a public nuisance. The mountain holds tremendous spiritual value in a number of Indigenous cultures and is a source of origin in many Native legends. The details of how the case played out are fascinating but a story for another day (ultimately, the ski resort won out). What’s perhaps even more interesting, in the big-picture sense, is how the resort’s controversial decision pointed to a future few could have foreseen decades ago. Using treated wastewater is becoming more and more common at ski resorts across the country. To the casual onlooker, it seems, well, icky. But some argue the strategy is actually part of a climate solution. Here are the dirty details.
Arizona Snowbowl was the first resort in the country to base its snowmaking operation entirely on treated wastewater. The move to use treated wastewater to make snow made sense from the resort’s perspective. By the early 2000s, they were experiencing short seasons and dry winters. They were short on both water and powder. So, where else could it look? Wastewater could help the resort extend its season and fill in gaps left by warmer weather and less snowfall.
Climate change certainly factored into the need. Studies show climate change has already reduced ski season by about a week across the country since the 1970s and cost ski resorts across the country billions of dollars cumulatively over time. The equation here is relatively easy to understand: Warmer temperatures mean a later start to the season, an earlier end, and lots of rain-on-snow events that make skiing less enjoyable—or even strip away snowpack entirely in parts of the country.
Snowbowl wasn’t alone in its desperation. To combat mild winters and low snowpacks, more and more resorts are becoming reliant on making snow. According to the National Ski Areas Association, or NSAA, about 260 resorts across the country—or 87% of the association’s members—make snow to create a reliable and consistent experience for skiers. According to the organization, about 17% of total skiable acres in the country are covered by manufactured snow.
Snowmaking itself began in the late 1950s. Fun fact: The first place to make snow was Grossinger’s Catskills Resort Hotel, the inspiration for the 1987 hit movie Dirty Dancing. In the decades since, the technology has come a long way, but the way it works remains roughly the same. Resorts pump water from a reservoir or other water storage, push air through that water to “atomize” it (break it into tiny crystals), then spray those droplets into the air with a cannon or fan, where they freeze into snow as they drift to earth.
It’s important to note that making snow requires reasonably cool outdoor temperatures. The sweet spot is around 28 degrees, although costly equipment can increase the workable temperature range (often resulting in subpar snow). Another side effect of climate change is that warmer temperatures are limiting the number of days in which snowmaking is possible at all. More snowmaking also equates to more emissions, which in turn fuels the climate crisis.
Snowmaking also relies—crucially—on an abundance of water, which was part of Arizona Snowbowl’s dilemma. The problem is easy to grasp: In a time of extended drought and development across the West, water is an increasingly limited resource. Snowmaking is one straw of many sucking at the water supply. An individual resort can use as much as 400,000 gallons a year for snowmaking. The state of Colorado is an interesting case study here. Ski resorts there use roughly 2.2 billion gallons of water annually to make snow. That’s enough water to fill about 3,300 Olympic swimming pools, but it’s still less than 1% of the state’s total water use. The NSAA also argues that snowmaking is a “nonconsumptive” water use since all that snow returns to the earth via runoff come springtime.
However, the process is still taxing on natural resources. Resorts often need to pump water from lakes, reservoirs, rivers, or streams near their operations. As water levels lower, fish, habitats, and ecosystems suffer.
Water issues don’t exist in a vacuum. As the ski industry grapples with drought, heat, and a reduced snowpack, resorts also contend with more traffic and, notably, more development. More people means more waste, and in remote mountain communities, there often isn’t an easy way to deal with it. Towns all over the country discharge treated wastewater straight back into waterways, and that water gets flushed back into the system. However, discharging that water straight back into the system can have a lot of negative impacts on water temperature, sediment in waterways, and other elements of aquatic habitat. In this sense, using wastewater to make snow can actually offer a win-win solution.
When using wastewater to make snow was proposed at Montana’s Yellowstone Club—a private ski resort for the mega-rich—and the nearby Spanish Peaks Mountain Club, both close to the west side of Yellowstone National Park, local conservation groups embraced the idea. It wasn’t just because the idea of billionaires skiing on poop is hilarious (though I contend it is). Rather, snowmaking with wastewater provides a secondary treatment to make the liquid even safer. When converted to snow, the water naturally seeps back into the water system during runoff, recharging flows in times of drought and boosting aquatic ecosystems. From this perspective, wastewater provides an artificial snow source that’s doubly sustainable. First, it means resorts don’t need to pull water (or at least not as much water) from rivers, streams, and reservoirs. It provides an independent source of water when the substance is increasingly scarce. Second, it adds water back to the system, recharging the aquifer and replenishing local waterways with cold water when those ecosystems need it most. In this case, using treated wastewater to make snow was viewed as a triumph rather than a tragedy.
To be clear, there are issues with using treated wastewater for snowmaking. The Hopi Tribe’s cultural concerns are very real, and just about all ski resorts operate on historically Indigenous land. There are also financial barriers. The Yellowstone Club devoted at least $12 million to its snowmaking technology using wastewater, and it relies on a new, $50 million wastewater treatment plant in adjacent Big Sky. Those numbers also don’t include the time and cost of permitting to make it all happen. Technology- and cash-intensive efforts like this are only replicable at the largest, most profitable resorts. Finally, as mentioned above, snowmaking itself is an energy-intensive endeavor. Increasing reliance on making artificial snow of any kind uses energy that itself goes back to fueling the climate crisis, making snowpack worse and contributing in a relatively small way to the need for more snow.
These days, Arizona Snowbowl’s not alone. At least a dozen resorts in the country use at least some wastewater to make snow. Looking ahead, more sources than ever will be slurping away at the water supply. Winters are projected to get milder and snowpack to get worse as areas around ski destinations develop more and more. Counterintuitively, using treated wastewater to bolster our fun on the slopes might be both a partial climate solution and a lifeline for the ski industry.
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