A major water main broke Friday in the city that supplies my drinking water. While we weren't without water as many were, we are under a "boil water for 5 minutes" order at this time. The most recent tests of the water came back clean, except for one area of 31 areas that was "inconclusive". Further results are expected today.

My question is: 5 minutes? What am I killing in there? They say fecal coliform - I don't think 5 minutes is required to kill that!! I've been using some bottled water we were given for drinking, and an electric teapot to boil what we need for cooking. Frankly, I'm not real worried about getting sick, but an ounce of prevention...

It's funny to hear people whine about who is going to pay for the bottled water "they need". I wonder if I can sell my recipe for boiled water to those clowns? I could make hundreds of cents doing so...wooo hooo

For someone in good health, where the worry is simple bacteria, bringing the water to a good, rolling boil is probably enough.

But the population includes the very young, the very old, and people with existing conditions or compromised immune systems. They're more vulnerable, and a gastrointestinal problem can set off a cascade of events.

A water main break can introduce various organisms -- there are too many unknowns. IIRC, some bacterial and amoebic nasties are harder to kill in the spore/dormant stage.

Given the potential legal implications, they're probably erring on the side of caution.

The length of time to boil water varies all over the map. I am sure your authorities were being overly cautious. My favorite authority, James Wilkerson, MD, in Medicine for Mountaineering, Fourth Edition, states:

"Even though water boils at a lower temperature at higher altitudes, the boiling temperature and the time required to reach that temperature are adequate to kill disease-producing microorganisms, including parasitic cysts, bacteria, and viruses....(Milk is pasteurized by heating it to 160F, or 71 C.)"
p.70-71.

The temperature for pasteurized milk is roughly the boiling point of water on the summit of Everest.

One reason for the longer recommended times for boiling may lie in the circumstance where you are sterilizing cloth for wound dressing. As I understand it, you need to that material for a longer period of time - I have no citations for that concept, however

It very well may have, Izzy. It's the same thing many of us experience when we travel to less developed countries on vacation and get a case of the runs--the locals have been living with the bugs in the water all of their lives while we haven't. The locals may still get sick from certain microbes or parasites, but many bugs don't bother them. Same thing with the boil order--some folks can get quite sick simply because they're not used to certain microbes that might be present in the suspect water.

Dougwalkabout makes an excellent point about erring on the side of caution when they suggest boiling for 5 minutes. There are just too many people with weak immune systems using municipal water to not try to be thorough. Heck, even during normal times, many of these people still need to boil the tap water.

It's an interesting topic as we enter the 21st century. Is the disinfecting/antiseptic/antibiotic/sterilize-everything approach the best way to live within a world teeming with microbes, or might strengthening our innate immunity and overall health, and living more in balance with nature, be more sustainable and effective over the long term? We already know that with antibiotics, we're "running out of bullets" as they say. And the lack of microbes appear to be harming our younger generations since humans involved to live with many microbes, particularly in our gut. The increase in asthma and allergies have been linked to this "Hygiene Hypothesis".

It may be hard to believe, but many immune functions require the presence of certain bacteria in our gut. Most of us would think that our bodies are totally self-contained and can carry out whatever functions it needs on its own, but that is turning out not to be true. We need microbes (certain ones, at least)!

Re: the 5-minute 'rule'...

They're probably erring on the side of caution because of a serious lack of common sense in a large part of the population.

The other reason is probably because a lot of people are unfamilar with boiling water. "Ah... just how should be go about that?"

Sue

Aside: Sue, I recall a "bachelor's survival" cookbook subtitled "Or, How Long do you Cook a 3-minute Egg?" Always cracks me up.

From the NOLS Wilderness Medicine book (page 250, 2008 edition):

"Incorrect information persists on how long to boil water before it is disinfected. The common diarrhea-causing microorganisms are sensitive to heat and are killed immediately by boiling water. The protozoa Giardia and Amoeba die after 2 to 3 minutes at 140 F (60 C). Viruses, diarrhea-producing bacteria, and Cryptosporidium cysts die within minutes at 150 F (65 C). By the time water boils, it is safe to drink."

Good luck!

Some bacteria are tougher than others, as Clostridium botulinum will survive boiling water for a considerable time, although the toxin is destroyed. To inactivate, it would probably be a good idea to give the water a blast with a Steripen as well, just to make sure.

This brings up an interesting side point -- Is a BIG pot a good piece of home gear?
2-10 liters? To sit on the stove for a water boil?

For one reason or another, I have usually boiled by water in order to purify it. I would obtain a large container suitable for boiling (I believe the largest I have is about 18 L - 20 quarts). I have many smaller ones as well which I often prefer for ease and safe handling. Your container should match your stove's capability - don't try to use a large container with a small heat source.

I sometimes boil a small container so that I can immerse it in a cool water bath in order to reduce the temperature. Having a big pot just gives you more options.