still having qualms about bleach to treat water : LUSENET : TimeBomb 2000 (Y2000) Preparation Forum : One Thread

Well, I was close to the point of buying some bleach to have on hand for treating water if necessary. I know it's supposed to be just regular bleach, sodium hypochlorite (ride?) of 5.25%. I was looking at the various plain bleaches that list 5.25% soduim hypochlor. and the remainder as "inert ingredients."

Is there some reason why the manufacturers don't include instructions or information about how to use the bleach for treating water right on the bottle?

Just call me leery of drinking chlorine....

-- winter wondering (, July 20, 1999


Inert means "having no effect" or "not active" -- in effect, it means 'harmless' in this instance.

BTW, nearby town uses straight bleach out of the bottle to purify their water supply.

Anita E.

-- Anita Evangelista (, July 20, 1999.

Perhaps this info from the Canadian government will help:

Ministry of Health, Health File #49b, August, 1997

Why should I disinfect my drinking water?

Drinking water is disinfected to kill disease-causing micro-organisms (bacteria, viruses and parasites) which may be in it.

Many different diseases are spread by drinking water contaminated by micro-organisms, including Campylobacter, cholera, amoebic dysentery, beaver fever (Giardia) and Cryptosporidia. These organisms usually get into drinking water supplies when source waters (i.e.. lakes, streams) or community water supply pipes or storage reservoirs are contaminated by animal wastes or human sewage.

In general, surface waters such as streams and lakes are more likely to contain disease-causing organisms than groundwater. Deep wells are safer than shallow wells. In fact, shallow dug wells are often as contaminated as lakes or streams.

When should I disinfect my drinking water

You should disinfect your drinking water if:

your community has been issued a boil water advisory;

you are using water directly from a stream, lake or shallow well;

lab tests of your water show that it contains "fecal coliforms";

an earthquake or other disaster has disrupted your community water supply;

you are traveling in an area where water is not well treated (third world countries); or

you have a weakened immune system (in which case you should disinfect all of your drinking water).

Disinfecting small quantities of water


Boiling is the best way to kill bacteria, viruses and parasites. A full boil for at least two minutes is recommended. At elevations over 2,000 meters (6,500 feet) you should boil water for at least three minutes to disinfect it.

NOTE: This is not appropriate for water that is obviously heavily polluted, or subject to chemical contamination.

To remove the flat taste of boiled water, leave the boiled water in a clean covered container for a few hours or pour the cooled boiled water back and forth from one clean container to another.

Disinfection using chemical methods:

Unscented household bleach (5% chlorine) can sometimes be a good disinfectant - e.g. when the water is not heavily polluted, or when beaver fever or cryptosporidiosis are not a concern.

Disinfection using bleach works best with warm water. Add 1 drop (0.05 mL) of bleach to 1 Litre of water, shake and allow to stand for at least 30 minutes before drinking.

Double the amount of bleach for cloudy water, or for cooler water.

 A slight chlorine odour should still be noticeable at the end of the 30 minute waiting period if you have added enough bleach.

The disinfection action of bleach depends as much on the waiting time after mixing as to the amount used. The longer the water is left to stand after adding bleach, the more effective the disinfection process will be.

NOTE: Bleach does not work well in killing off beaver fever (Giardia) or Cryptosporidium parasites. The amount of bleach needed to kill these parasites makes the water almost impossible to drink. If beaver fever or Cryptosporidium are in your water, boiling is the best way to ensure safe drinking water.

Chlorine Tablets:

Follow the manufacturers' directions.


Whenever possible use warm water (20 0C) and let stand a minimum of 20 minutes after mixing and before drinking.

For cold water (5 - 150C) increase the waiting time after mixing to 40 minutes.

If you are using 2% tincture of iodine, use 10 drops (0.5 mL) for every one litre of water.

With iodine tablets, follow the manufacturer's directions.


Pregnant women should not use iodine drops to purify water as it may have an effect on the fetus.

Iodine should not be used to disinfect water over long periods of time as prolonged use can cause thyroid problems.

Disinfecting larger amounts of water in tanks or barrels

Always use clean containers which are designed for storage of food or water. You can use regular household bleach (usually about 5% chlorine) or commercial bleach products (usually 10% chlorine).

The table below shows how much regular household bleach to add to various size water containers to disinfect relatively clean water.

If you are treating water from a lake, stream or shallow well, use twice as much household (5%) bleach as indicated in the chart below and wait twice as long before drinking it because it is more likely to contain chlorine-resistant parasites from animal droppings. Let the water stand for at least an hour after adding the bleach before you start drinking it. If the water is colder than 100C or has a pH higher than 8, let the water stand for at least two hours before drinking.

Gallons of water to disinfect (equivalent shown in brackets)

Amount of Household bleach(5%)to add *

1 gal. (4.5 litres)

2 drops (0.18 mL)

2 1/5 gal. (10 litres)

5 drops (0.4 mL)

5 gal. (23 litres)

11 drops (0.9 mL)

10 gal. (45 litres)

22 drops (1.8 mL)

22 gal. (100 litres)

3/4 teaspoon (4 mL)

45 gal. (205 litres)

1 1/2 teaspoons (8 mL)

50 gal. (230 litres)

1 3/4 teaspoons (9 mL)

100 gal. (450 litres)

3 1/2 teaspoons (18 mL)

220 gal. (1000 litres)

8 teaspoons (40 mL)

500 gal. (2200 litres)

6 tablespoons (90 mL)

1000 gal. (4550 litres)

6 1/2 ounces or 12 tablespoons (180 mL)

*Adding household (5%) bleach at these amounts will produce water with about 2 parts per million of chlorine in it (about 0.0002 percent).

-- Old Git (, July 20, 1999.

Hi, winter,

I am a former hydrologic technician; worked for US Forest Service and US Geological Survey. Also have done lots of water for land sales/ purchases as a general contractor for the last fifteen years. I'd like to add a couple of comments to those made by Old Git:

First, chlorination of drinking water is used by most municipalities because it is relatively cheap and effective. However, it is recognized as a less than ideal method of treating water, because the chlorine can react with organic matter in the water and cause carcinogenic material to form. If you need to chlorinate your water, you probably have some organic matter in the water, so bear this in mind.

You can remove most of the chlorine (and, I suppose, but am not sure, the carcinogenic material, by filtering the chlorinated water through activated charcoal. There are many, many brands of charcoal filters on the market.

Because of the carcinogens in chlorinated water, many people avoid drinking "city" water, preferring to buy a non-chlorinated bottled water. Many of my friends and I generally bring our own well water or spring water to town when we have to go there.

Nevertheless, chlorinated water is not such a great threat that I won't ever drink it. Certainly I would drink it in an emergency. When I travel to Latin America I chlorinate the water even after filtering it.

It is highly advisable to filter any surface water source if there is any possibility of Giardia. You'd have to talk to someone at your local health department to find out if Giardia is a threat in your area. Giardia is a paramecium, and it quite large, as far as "bugs" in the water go, and can be filtered out by any good water filter. This is different than bacteria, for instance, which require a filter size much smaller than the size needed for Giardia.

Old Git mentions the necessity to treat your water if a water has been tested and has "fecal coliform". This is an "indicator" species which shows that the water has been in contact with the feces of a warm blooded animal. I recommend, and it is the law where I live, that you treat water if the lab tests show the presence of ANY coliform bacteria, not just fecal coliform. The appropriate test is called "total coliform". It is the standard test used here (Oregon) to test the sanitary condition of wells, etc.

Neither fecal coliform nor total coliform are considered hazardous; as I said, they are only "indicator species", that is, the are an indication that the water is not safe to drink because it has been exposed to some contamination. The "total coliform" test shows whether the water has been exposed to ANY organic matter. Even leaves contain the coliform bacteria which is tested for in this test. But the point is, if the water has been exposed to, for instance, leaves, then the water has had the possibility of being exposed to other disease agents which are present in the environment.

By the way, many (maybe most) waterborn pathogens attach themselves to particulate matter in the water, so if the water is very dirty looking, it certainly has a higher potential to be unsafe to drink than very clear water. Not that clear water is necessarily safe to drink! But for this reason, it is generally thought that it is safer to drink water from far out in a lake, where the sediment has had a chance to settle out, than from the stream feeding the lake itself.

Hope this helps.


-- jumpoffjoe (, July 20, 1999.

Winter wondering:

I used to do backcountry camping and "survival" camps, especially on the Cumberland Plateau in Tennessee.

I always used surface water, and always disinfected it with bleach. I've done this many times. If you follow directions, it is not harmful.

-- Jon Williamson (, July 20, 1999.

where can one find Iodine tablets?

-- I'm (, July 20, 1999.

Winter Wondering (thanks for your reassuring answer to my post a couple days ago about food storage--nice to know others have my questions, sometimes feel very isolated!) About chlorine disinfection, the information I have from local Coop Ext (NYS)is 8 drops/gal, with another 2-4 drops/qt if water is cold or cloudy. Should have a slight chlorine odor. 8 hrs wait time is preferable, but at least 30 min. This source said bleach does kill Giardia but not as well as iodine. Iodine treatment if with 2% tincture, 5 drops/qt, 10 drops cold or cloudy H2O. Again, 30 min is good but 8 hrs is better.Best is boiling for 15 minutes. In terms of chlorine in the water, I think you need to look at the big picture. Chlorine is used in our municipal water supply and since my house is relatively close (1.5 mi) to the plant, our water smells like a swiming pool! (I gather it dissipates over distance so they have to put in a lot for those 'further along' the pipe). I'm aware of the long-term carcinogenic threat, but in terms of Y2K I think your immediate concern is being able to drink, and the cancer threat needs to be shelved in one of those "least of my worries" compartment! (BTW, the kinds of differences in Old Git's info vs mine are what drive me a little nuts about prepping--there seem to be such a variety of answers--do I go with Canada or NY advice? It seems everything I "learn" has another 2 or 3 or 4 points of view.....)

-- Deb (, July 20, 1999.


You wrote: "(BTW, the kinds of differences in Old Git's info vs mine are what drive me a little nuts about prepping--there seem to be such a variety of answers--do I go with Canada or NY advice? It seems everything I "learn" has another 2 or 3 or 4 points of view.....) "

Boy do I hear you on that one! It really starts to feel like one is going 'round in circles. At least I do. I guess we each will just have to wade through the info out there. For now I've been printing out info on different things for reference. Where there are discprepancies, I guess I'll go with 'majority rules' or what seems to be the safer bet.

We have great well water. And we have a spring that used to be the absolute best water-- but not so sure of the quality these days. I hate chlorinated water and am glad I'm not on a municipal system that uses it.

Boiling-- I've heard anywhere from 2 minutes to 15 minutes. Two trusted sources give a minimum of 10 minutes. 10 minutes it is. From the time it starts to boil. (It takes more time than you might think to get a good amount of water to a rolling boil...) Lot's of fuel.

Filters & purifiers-- since we may run out of fuel for boiling water, I've been thinking along the lines of a back-up or two of a water filter or purifier. There are differences and also differing recommendations. My initial thoughts were for getting one that can filter the most # of gallons before replacement. Then some said that one was tough to pump. I also like the looks of some of the 'gravity' filters that sit on the counter and you put the questionable water in the top and it filters through into the bottom. One of my concerns with either of these types is "cold performance"-- the countertop one is gonna freeze for sure in the event of an extended power outage (which face it, is the only reason for having the filter in my case in the first place...). The other types can be drained out and hopefully that won't be a problem.

I wrote a thread a little while back (one week, two weeks?) about feeling overwhelmed. Well, sign me "Still overwhelmed"

Take care all.

-- winter wondering (, July 21, 1999.

Just to add a note I heard somewhere here: Shaking up the water prior to drinking will airiate (-10 for spelling) and make it taste better.

JOJ, I have a question please: Should folks try out these various methods well ahead of time or before investing alot of cash in a particular type of water purification tablet, method, etc? I am just wondering out loud if some folks may have a reaction/allergy to some particular type of tablet?

We had some sort of tablets for camping sometime ago. I made the family use them at home first. I have forgotten what type they where, but the water would definitely fall under the catagory of "an aquired taste"...reminded me of seriously treated city water. However had no adverse effects except the taste.

-- Lilly (, July 21, 1999.


I think it's always a good idea to test out anything you are using for emergency use, whether it is a water treatment system, solar panels, or whatever.

Someone on this thread mentioned possible side effects from using iodine. That's a new one to me, but sounds credible. I do know that iodine does have the reputation for tasting pretty bad.

I think it's pretty safe to say that chlorinting water of dubious quality is probably the most acceptable idea to most people; after all, probably over 200 million people drink chlorinated water year round--it's gotta be ok for short term, which all the y2k problems will probably be. If they aren't short term, worrying about carcinogens from chlorinated drinking water is not going to be high on our priority lists.

Again, even some very inexensive filters will increase your security by filtering out some of the larger organisms. Check your local sporting goods store, REI, etc. Or maybe do a search on the net for water filters.


-- jumpoffjoe (, July 22, 1999.

Lilly & JOJ--Iodine disinfection is not recommended for people with thyroid problems. I believe people can have allergic reactions to iodine so I would certainly test it out. I've read that using a little crushed vit C tab to the iodined water blocks the iodine taste but I haven't tried this out. I think personally I will go with chlorine. Regards,

-- Deb (, July 23, 1999.

Y2K, ` la Carte by Dancr near Monterey, California

Many of the larger pore filters (such as Britta), while not adequate against viruses and smaller bacteria, are well able to filter out the chlorine and iodine tastes. You can treat first, wait 30 minutes for the treatment to take effect, and then filter out the chemicals. Then shake to reintroduce oxygenation. (Dancr avoids above spelling problem :> )

-- H20_Dancr (addy.available@my.webpage.neener.autospammers--regrets.greenspun), July 23, 1999.

The Chlorox company's directions. Straight from the horses mouth.

-- tree (, December 14, 1999.

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