Treating Water

For Crypto, from the CDC web site
<p class=”p1″><span class=”s1″>Methods that may remove some or all of Cryptosporidium from drinking water are:</span></p>

<ul class=”ul1″>
<li class=”li1″><span class=”s1″>Boiling (Rolling boil for 1 minute) has a very high effectiveness in killing Cryptosporidium;</span>
<li class=”li1″><span class=”s1″>Filtration has a high effectiveness in removing Cryptosporidium when using an absolute less than or equal to 1 micron filter (NSF Standard 53 or 58 rated “cyst reduction / removal” filter);</span>
<li class=”li1″><span class=”s1″>Disinfection with iodine or chlorine is not effective in killing Cryptosporidium;</span>
<li class=”li1″><span class=”s1″>Disinfection with chlorine dioxide has a low to moderate effectiveness in killing Cryptosporidium;</span>
<li class=”li1″><span class=”s1″>Combination filtration and disinfection has a very high effectiveness in removing and killing Cryptosporidium when used with chlorine dioxide and an absolute less than or equal to 1 micron filter (NSF Standard 53 or 58 rated “cyst reduction / removal” filter).</span>

http://www.cdc.gov/healthywater/drinking/travel/backcountry_water_treatment.html

I tried to find a similar statement on the Olympic National Park website without luck.

The warnings are there. For example, the Ozette Loop page says, “Cryptosporidium and giardia exist in coastal streams and rivers; therefore, always filter or boil water. Iodine is ineffective against cryptosporidium.”

Bruce & Bob,

Thanks for the confirmation.

Started to think I imagined it.

Yep, although it’s important to note that not all chemical treatments are created equal.  Iodine and free chlorine are not always effective against giardia and crypto.  Chlorine dioxide *is* effective, although it might require a long contact time and a filter might be preferable.

Well, no water treatment is absolute. Even boiling has the potential (statistical probability) that something will penetrate your natural defenses.  ALWAYS! High pressures, and longer cycling times are needed to create completely sterile items. Or, High Radiation (not particulate) will also create sterile water. .

A lot depends on your water supply. What you start with will certainly determine the outcome.  The signs are accurate but in many cases are a bit overdone. You are generally subject to all sorts of potential pathogens. Don’t worry about it. If you get sick, most diseases have cures, today. And, they will take a while to manifest…often a week or two, some much longer.  The biggest problem with most treatments today is freshness and concentration. But, even a single egg from a trichinosis worm can infect you. And, these are generally very resistant to chemical treatment. Boiling is the safest, but we find many organisms that live in boiling water,  again, not really sterile.  You would really worry if you studied microbiology. But, for the most part, they work well enough to kill most organisms to let our natural defenses (built up through evolution) work. It is not something I worry about when I am out.

Just take the best precautions you can. Boil water, treat with chemicals, filter stuff with a fine absolute filter, and/or radiate (UV) your water. It still won’t be sterile, but statistics say one in a million will get sick. I will live with those odds.

Read Cafins water treatment  series. It is old, but NOT obsolete.

Here are the articles

https://backpackinglight.com/water_treatment_methods_part1/