Month: September 2017

Water Treatment for Hikers, Vol. 2 – Water Treatment Methods

Water Treatment for Hikers, Vol. 2 – Water Treatment Methods

When I was a kid, I ran all over the mountains and foothills of the Mid-Atlantic drinking water out of streams and other running bodies of water. When I got in the military and got into the medical field, I REALLY learned about the importance proper hydration and water treatment. In the military, the most common method of treating water is water purification tablets (Iodine) or Aquamira.


In this episode, I am going to talk about the different popular methods of water treatment and try to hit their pros and cons. I will also try to give some examples of each where applicable.


Pump Water Filter/Purifier – A mechanical filter works by pumping water through microscopic pores in some sort of filter element. The downside to mechanical filtration is that the filter is going to get clogged up, requiring you to clean out the system and eventually replace it. Mechanical Water Purifiers work in a similar fashion to filters, but can remove Viruses.


  • You can get water from pretty much any source
  • You can get your water quickly
  • You can replace the filter element
  • You get exactly as much as you need


  • Heavier than most of the other options
  • You must clean the filter
  • You must pump the filter
  • Price

MSR Guardian – MSR’s flagship, it pumps up to 2.5 liters per minute and 10% of every pump stroke serves to backflush the filter, saving you from having to clean it like other filters. This purifier filters particles down to 0.02 microns… small enough to filter out viruses. The filter cartridge is rated for 10k liters and is replaceable.  $350

Katadyn Pocket Water Filter – Katadyn’s flagship, it is effective only against bacteria and protozoa due to it having a pore size of 0.2 microns.  Good for 1 liter per minute, the filter cartridge has a life of 13K liters . $240


Gravity Filter – Gravity filters work like pump filters. The difference is they work via…. you guessed it, gravity. You place dirty water in a dedicated dirty container and then let it flow down via gravity to a clean container.


  • Easy to replace cartridges
  • Good for a large group
  • You don’t have to do much, just let gravity do the work


  • Slow
  • Requires you to clean the filter frequently
  • Hard to get water out of shallow sources

MSR Autoflow/Platypus GravityWorks – Similar offerings from two different companies, both are easy to use to filter large quantities of water. About $100. MSR Autoflow


Squeeze Filter – Squeeze filters work similar to gravity filters but instead of waiting for gravity, you force the water through the filter cartridge by squeezing water from a dirty “source” bag/bottle to a “clean” reservoir.


  • Inexpensive
  • Easy way to quickly filter a small amount of water
  • Small and light


  • Frequent backflushing is generally required
  • Can only filter in small amounts generally due to reservoir size

Sawyer Squeeze/Sawyer Mini – both are very popular among hikers. Easy to use, pain in the butt to have to regularly backflush, they are a readily available, inexpensive option. $20-$40 Squeeze Mini

MSR Trailshot – MSR’s answer to the Sawyer Squeeze, this is a nice little filter. Weighing in at only 5 oz, it fits in a pocket and efficiently filters one liter per minute. $50

Chemical Treatment – Effective against bacteria, protozoa and viruses, chemical water treatment is a cheap and easy to use option. Mostly chlorine or Iodine based, they usually come in pill or drop form.


  • Easy to use
  • Cheap
  • Ultra-light weight


  • VERY slow. Usually you have to wait 30 minutes or longer for them to work
  • Can leave a chemical taste
  • Can be some concerns with different medical conditions
  • As we mentioned in Vol. 1, not as effective vs Cryptosporidium, you MUST use the proper amount and wait the proper time or it is useless.

Aquamira – a binary system, you mix part A and part B then add to water. No taste. Works well on Cryptosporidium. Kit treats up to 30 gallons. $15

Potable Aqua – Iodine based tablets. Awful aftertaste. Not good vs Cryptosporidium. $7, plus $5 for the taste neutralizer tablets.

MSR Sweetwater Solution – For use with the Sweetwater Pump Filter, this adds virus protection to a popular MSR filter. $15 for up to 80 gallons.

UV Treatment – Stick your little battery-operated wand in a bottle of water, press and hold the button and 60 seconds later you have drinkable(ish) water. Effective against bacteria, protozoa and viruses.


  • Ease of use
  • No cleaning required


  • Doesn’t work as well in water that is cloudy or silty
  • Batteries necessary
  • One bottle at a time
  • After treatment, cloudy water is still cloudy water, just drinkable now.

SteriPen– able to purify about 50 liters per set of 2AA alkaline batteries. Prices range from $60-$100 depending on model.


Boiling – You gather some water and bring it to a boil for at least 1 minute, longer at altitude.


  • Easy to do
  • Very cheap
  • Cloudy water still boils


  • Water needs to cool down
  • Water must boil
  • Fuel is required
  • If open flames are banned, you are screwed.



Tips :

  • Because more people and livestock live at lower elevations, water at higher elevations is generally cleaner
  • That cattle stock pond over there? Don’t drink from it unless you must, and if you do, treat for viruses
  • Avoid stagnant ponds in heavily logged area. Heavy metal run off is a real thing.
  • Use LNT principles and do not camp, use the bathroom or clean dishes within 200ft of water sources
  • Seek out clean running water over stagnant murky water
  • Follow all product directions. If you don’t you might just be wasting time and inviting disaster.
  • Source clean water activities upstream of dirt water activities
  • After a heavy rain, wait a short while before gathering water from a ground source. Water washing over surface areas stirs up mud and increase bacterial load.
  • Use a prefilter if you have one, or make one with a bandana
  • Get water from the surface, sediment and other gunk sinks
  • Wash your hands
  • Keep dirty water and clean water separate

Water Treatment for Hikers, Vol. 1 – Why we treat our water

Water Treatment for Hikers, Vol. 1 – Why we treat our water


One of the most important resources for a hiker is water. Without proper hydration, any hike you have planned is pretty much doomed. Without clean water, any efforts you make to maintain proper hydration are going to end poorly. Bacteria, viruses and parasites can be real problems and can have a real, sometimes life-threatening, impact on your hike.



What do you think was the biggest killer of soldiers during the US Civil War?

According to research done by historians for every 3 soldiers killed in battle, 5 died from disease. The diseases with the biggest death tolls were dysentery and typhoid.  According to records Dysentery was by far the biggest killer. Think about that. In a war where roughly 620,000 Americans soldiers died, approximately 65% died from disease, with dysentery being the biggest culprit. Dysentery is a type of gastroenteritis that results in diarrhea with blood. The diarrhea is so severe that your bowels are being evacuated faster than you can hydrate your body. This is a serious, life threatening situation and medical treatment is a necessity. 

                Dysentery can come from bacterial, viral or parasitic causes, so  let’s examine what lurks in our water that can affect our health. Amng the thing hikers will face, the 4 we will most likely encounter are bacteria, viruses, parasites and chemicals. Of those 4, here in the US we will be LEAST likely to encounter viruses and that will have an impact on how we treat our water as we will discuss later. The 5 most common things found in streams/ponds/lakes are Giardia, Cryptosporidium, E. Coli, Cholera, and Typhoid Fever (Salmonella Typhi).


Bacteria are single celled prokaryotic organisms. Prokaryotes are organisms without a cell nucleus, or any other membrane-bound organelles. What does this mean to you? Nothing. I am just being all sciencey. Bacteria can be beneficial or harmful. In the human body, bacteria are everywhere but since your immune system limits their growth in many systems, they are found in the largest numbers on your skin and in you GI tract. In a milliliter of fresh water, expect to find a million bacterial cells.  Common bacteria that concern hikers are E. Coli, Cholera (Vibrio cholerae), and Typhoid Fever (Salmonella Typhi).


A virus is an infectious agent that only replicates INSIDE the living cells of other organisms. Viruses found in water include but are not limited to Hepatitis, SARS, Polio, and Hand, Foot, and Mouth disease caused by Coxsackievirus or Enterovirus. Much less common in water sources in the United States (actually VERY rare), we aren’t going to really cover them.  Quick story. This past summer (summer of 2017) I was volunteering as a camp nurse for my church’s kids camp. We actually had a couple cases of Hand, foot, and mouth disease among the campers. These were the first cases of the disease I have ever seen in the US, but I suspect they came TO camp with the disease since they presented with symptoms in the first 2 days of camp. We immediately isolated them and sent them home for treatment.


Protozoa and Cysts are single-celled organisms, usually found in food and water that is contaminated by animal waste. Common protozoa encountered by hikers are Giardia Lamblia (giardiasis) and Cryptosporidium parvum (cryptosporidiosis).


Chemicals in water are extremely varied. The most common sources of chemicals in water is industrial or agricultural runoff. So many different varieties of chemicals are pumped into our water that I am not even going to get into them. Let me just say that you should exercise caution when drinking water from a source near any factory or farm, even more so from water that isn’t flowing. High concentrations of chemicals can NOT be reliably removed by either portable filters or purifiers, so again, be VERY cautious.


Below I list the 6 most common contaminants hikers might encounter. We are going to cover general signs, symptoms, and how to treat.


  • Giardiasis – Giardiasis is a parasitic infection caused by a protozoa, Giardia Lamblia. Giardia is one of the most common waterborne pathogens around the world and is transmitted via the fecal-oral route from ingested cysts. Also called Beaver Fever, it is caused by contaminated fecal matter entering a water supply. Unless you are one of the lucky who are asymptomatic, you will experience-
    • Diarrhea
    • Abdominal pain
    • Weight loss secondary to the infection blocking nutrient absorption in the small intestine
    • Less common are vomiting, blood in the stool and fever

Since Giardiasis usually resolves on its own, treatment involves treating the symptoms via hydration. Prevention is a matter of hygiene, to include hand washing and proper water treatment. All traditional water treatment methods are effective vs Giardia


  • Cryptosporidiosis – Cryptosporidiosis is caused by a cyst, Cryptosporidium parvum, that can cause respiratory and gastrointestinal illness. Cryptosporidium is also a very common pathogen. Like Giardia, transmission is generally via a fecal-oral route, but unlike Giardia it can also be transmitted via a respiratory route.
    • Watery diarrhea with or without a persistent cough

Treatment of Cryptosporidiosis is similar to Giardiasis, meaning you treat the symptoms via re-hydration and electrolyte therapy. Prevention is also similar, combining hygiene and proper filtration, but Cryptosporidium is highly resistant to chlorine disinfection, so if going that route make sure you use the proper concentration and that you treat the water for the correct length of time.


  • E. Coli infection – Most strains of Escherichia Coli are non-pathogenic to humans. As a matter of fact, I GUARANTEE you have E. Coli in your GI tract right now. While there are also virulent strains of E. Coli that can cause sever life threatening illnesses, as hikers we focus on strains that cause gastroenteritis. Symptoms include-
    • Nausea, vomiting, and diarrhea.

Treatment once again includes treating of symptoms and in since it is a bacteria, properly prescribed and administered antibiotics will effectively shorten the course of the illness. Since transmission occurs through the fecal-oral route, prevention comes down to proper hygiene, cooking of food, and effective water treatment. All the traditional forms of water treatment are effective.


  • Typhoid Fever – is NOT Typhus. Typhoid fever is cause by Salmonella Typhi, a bacteria. It is generally a 3rd world disease, transmitted via the fecal-oral route in contaminated food and water. Due to poor hygiene, it is a SERIOUS problem in India. INITIAL SYMPTOMS include
    • Fever (primarily a fever that rises in the afternoon), bradycardia (slow pulse), malaise, headache and cough.

Symptoms that occur as time goes by are progressively worse and involve more body systems with serious complications. Typhoid Fever is usually spread via a fecal-oral route, but can be spread by flying insects feeding on feces. Proper hygiene is necessary to prevent Typhoid Fever and all traditional water filtration forms are effective. Prevention is possible via vaccination and treatment includes treating of symptoms and antibiotics.


  • Cholera – cause by some strains of Vibrio cholerae, Cholera is a bacterial infection of the small intestine. Symptoms can range from none to mild, to sever, and can include-
    • Watery diarrhea that lasts a few days
    • Vomiting
    • Cramps

Transmitted via a fecal-oral route through contaminated food and water, with under-cooked seafood being a common source. Prevention includes vaccination, hygiene and water treatment, with all common water treatment forms being effective. Treatment includes treating of symptoms to include re-hydration and electrolytes therapy and antibiotics.


  • Norovirus – I am including Norovirus because of recent outbreaks on the AT. This is the outlier in the group. The general rule of thumb is that viruses aren’t an issue for hikers in the US. Every spring lately, at about the NC/TN line on the AT people are coming down with the virus. The symptoms include…you guessed it, GI issues. So now you have a bunch of people puking and crapping all over the trail, further contaminating the environment and spreading the virus to each other from the Smokies all the way up to Maine. Prevention includes good hygiene and water treatment, BUT since a virus is WAY smaller than the bacteria and cysts that filters are designed for, thus a water filter won’t do squat for a virus unless it is also a purifier or has a chemical purification component. Treatment involves treating the symptoms and giving your body time to heal itself.


In the next installment, I will discuss Water Treatment options.

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