Up to date April 2, 2026 01:42PM
As I crunched alongside the dry riverbed deep within the southern Utah backcountry, I mentally tabulated my water provide. I wasn’t out of water, however I attempt to refill each likelihood I get within the desert. So once I noticed a big puddle, I opened my filter bottle and tanked up. I briefly questioned whether or not I used to be operating a danger by consuming from such a stagnant supply, however my provide was low sufficient, and the upcoming watering holes weren’t assured. I made a decision to drink it.
I’ll by no means know if it was that puddle or the gas-station fried hen I purchased on the drive dwelling, however 4 days after the journey, I sat doubled over at pressing care feeling like my inner organs have been trapped in a vise. I examined optimistic for Campylobacter, dragged myself to the pharmacy for antibiotics, and went dwelling to thrash round by means of waves of nausea and stabbing cramps.
I’m very cautious about treating my water. However within the backcountry, there are sufficient variables that nothing is assured. Suppose: forms of pathogens, contaminated filters, mindlessly rinsing your bowl at camp with untreated water. I nonetheless received sick, and this explicit bacterial an infection is one thing I wouldn’t want on my worst enemy.
And but, some backpackers nonetheless ask: Do I actually need to filter my water? It’s shifting quick / I’m at a excessive elevation / It appears to be like clear / I can see the supply / there aren’t any animals round.
Simply because water appears to be like clear doesn’t imply it’s. In a viral 2018 story for Slate that’s nonetheless in circulation at present, author Ethan Linck claimed contaminants are uncommon in backcountry water sources within the US and Canada and that filtering is pointless, citing proof that included a collection of exams this journal did twenty years prior. In 2026, nonetheless, exceptions abound. Experiences have discovered microplastics in “pristine” Adirondack lakes, and Lonesome Lake within the Wind River Vary is closely contaminated with human fecal matter.
A 2019 paper printed within the Nationwide Library of Medication recommends treating all probably non-potable water sources, saying that “even in developed nations with low charges of diarrheal sickness, common waterborne illness outbreaks point out that the microbiologic high quality of the water, particularly floor water, just isn’t ensured.” Treating water takes additional time and vitality, however I’m a robust believer in doing every part you’ll be able to to keep away from an infection. And once we talked to the specialists, they agreed.
What sort of pathogens are in backcountry water?
“The 2 largest sources of danger within the backcountry are the presence of protozoans and micro organism,” says Dr. David Dyjack, Dr.PH, chief government officer of the Nationwide Environmental Well being Affiliation. In accordance with Dr. Dyjack, the “single largest concern” for backcountry water is tiny, chlorine-resistant parasites like Giardia and Cryptosporidium.
These parasites are present in areas frequented by wildlife and livestock, will wreak absolute havoc in your GI tract, and are particularly harmful for immunocompromised people or anybody with underlying medical circumstances.
“Pathogens continuously originate in fecal matter and get washed into water sources throughout rain occasions or melting snow,” says Dr. Kaitie Sniffen, PhD, who has spent 10 years working in water-related fields and likewise occurs to be a thru-hiker. It ought to go with out saying that she additionally treats her water.
Even when the climate is dry and also you don’t see any cows wandering round, “many pathogens can stay as much as a number of months in moist environments,” she provides. Some stay in soil and water, creating danger even within the absence of fecal matter.
Waterborne infections can happen wherever, although frequency and pressure differ by geography. The Western US’s greater elevation, colder local weather, and decrease inhabitants density usually lead to greater charges of Giardia, whereas the Midwest’s grazing and foraging livestock result in greater charges of micro organism, says Dr. Dyjack. The japanese forests alongside the Appalachian Path have denser inhabitants facilities and busier trails, and hikers can count on each protozoans and micro organism to be current.
What about shifting water?
A standard sentiment amongst thru-hikers and backpackers is that fast-moving creeks and streams are safer than stagnant water, reminiscent of ponds and cow tanks, and there may be some fact to this.
“Quick-moving water tends to dilute pathogen concentrations, which helps scale back progress and expose organisms to daylight and oxygen,” says Dr. Dyjack. Nonetheless, he stresses, protozoans can nonetheless be current, and it’s necessary to keep in mind that flowing water doesn’t take away danger.
Whereas clear, odorless, shifting water is much less more likely to be filled with pathogens than pungent, stagnant water (and sources faraway from human influence may be safer), we don’t know what lies upstream, and you’ll’t see pathogens with the bare eye.
Bearing in mind variables like rain, snowmelt, flooding, and elevation, Dr. Dyjack estimates the likelihood of a protozoan being current in an untreated wilderness water supply is “80-90% on most days, in most areas.”
Local weather change and excessive climate (suppose wild swings in drought and flood cycles) introduce extra danger. Droughts can focus microorganisms that choose heat environments, and subsequent flooding or heavy precipitation can distribute them all through the ecosystem. All of it stacks as much as some fairly excessive odds of ingesting one thing you don’t wish to.
It’s exhausting to nail down the chance of getting sick, however the Facilities for Illness Management notes that wholesome individuals have develop into ailing after consuming as few as 10 to 30 Cryptosporidium cysts. When you have been to devour water contaminated with considered one of these or related pathogens and develop into contaminated, you’ll often begin to expertise signs inside 1-14 days, says Dr. Sniffen. The commonest signs of those waterborne pathogens are diarrhea and vomiting, which may result in dehydration, in addition to abdomen cramps, nausea, and typically fever.
Water remedy choices
There are a number of methods to deal with water within the backcountry to make it safer to drink, some simpler than others for various kinds of pathogens.
In accordance with the CDC, boiling is the simplest approach to kill all germs, but it surely received’t take away particles like microplastics from the water. The precise water filters take away this particles whereas serving to forestall bacterial and parasitic infections. Nonetheless, most don’t take away viruses. To do this, you’ll want a air purifier just like the MSR Guardian or Grayl Geopress, that are heavier than many hikers wish to carry.
Chlorine dioxide remedies like Aquamira generally is a good disinfecting possibility, however they don’t work as properly when the water is cloudy, and may be much less efficient in opposition to powerful parasites like Cryptosporidium, says meals security knowledgeable Humberto Maldonado. For really contaminated water, redundancy is your finest guess.
TL;DR: Do you should deal with your water within the backcountry?
The quick reply is sure, backpackers ought to deal with water within the backcountry to guard themselves from waterborne sicknesses.
The 2 minutes saved by not treating water isn’t well worth the elevated danger of an infection, and consuming untreated water doesn’t put you “extra in contact with nature,” as somebody as soon as scoffed at me throughout a thru-hike. It simply raises the chance that you simply’ll be thrashing round within the iron grip of Giardia or Campylobacter for so long as it takes to stagger to city for antibiotics.
“The one time I might say it’s alright to not deal with water can be in case you are experiencing a better danger than getting a waterborne sickness,” says Dr. Sniffen. “If you’re stranded within the wilderness, are awaiting rescue, and haven’t any approach to deal with your water, then sure, consuming untreated water is healthier than dying of dehydration.”
Nonetheless, she continues, “When you’ve got ever lain on the chilly rest room ground feeling such as you have been going to die after having to make the last word double-dragon resolution, simply think about how a lot worse it could be in the event you have been 60 miles from the closest city. It’s simply not well worth the danger.”
