types of water treatment devices which can be used during an emergency to
provide a continuing supply of drinkable water. This water can then be
stored in one or more of the systems discussed in the preceding sections.
In times of any
disaster, always assume that any water that has not
or purchased and stored is contaminated.
If water is brackish, first strain
the debris through a paper towel, clean cloth or coffee filter. Then treat
by one of the methods below.
Unpurified drinking water may
contain four things that pose health risks:
Protozoa include the well-known
Giardia and Cryptosporidium. These have been detected in 90% of
U.S. surface waters and are very common in Canada. Protozoa are the
largest organisms of the three pathogen categories, ranging in size from
1-16 microns (one micron - 1/1000 of a meter).
They are more resistant to
disinfection by iodine or chlorine than either bacteria or virus, but can be
effectively filtered with the proper technology. Giardia are
relatively large and easy to catch, but "Crypto" is smaller, more likely to
pass through units which depend upon filtration for parasite removal.
Devices which protect against
Crypto must be proven to remove 99.9% of this organism.
Bacteria include commonly-known
organisms such as Campylobacter, E. coli, V. cholera, and
Salmonella and are intermediate-sized organisms, ranging from 0.2 to
about 10 microns. Disinfection can effectively filter by any filter that is
proven to remove 99.9999% of bacteria.
Commonly known viruses include
Rotavirus, Hepatitis A, Norwalk and Polio. Viruses are minute;
they range in size between 0.02 and 0.085 microns, making them extremely
difficult to filter. Viruses respond well to certain types of disinfection
and can be effectively inactivated using a process proven to remove or
inactivate 99.99% of virus.
chemicals may not pose an immediate health threat as do pathogenic
micro-organisms but can destroy great numbers of healthy cells, thus
reducing the body's immune capabilities and perhaps opening the door to some
type of illness or organ malfunction later.
Even simple chemicals such as
chlorine, in high levels, from swimming pool water, should be avoided
through the use of proper filtration techniques.
The vast majority of pathogens are
introduced by animals, but human beings are also carriers. Feces wash into
drainages, carrying with them the disease-causing pathogens. Water moving
through the drainages spreads pathogens downstream. Waterborne viruses are
unique in that they are species-specific; i.e. human fecal matter must be
present for there to be a viral threat to humans. This entire scenario is
worse during an emergency.
Reactions to drinking contaminated
water range from no symptoms at all, to desperate illness, or death for some
immune-compromised individuals. Your reaction will depend on the specific
pathogen and on your immune system. Immune systems vary from individual to
individual, based on genetic make-up and medical history.
If you are exposed to pathogenic
micro-organisms, you may be one of the lucky few who experiences few, mild,
or no symptoms. For the rest of us, after drinking contaminated drinking
water, there will be an incubation period of between a few hours (e.g.
Salmonella) and a couple of months (e.g. Hepatitis A or C),
during which no symptoms will be evident. During this time, the pathogen is
invading your system and multiplying. When concentrations of the pathogen
reach a certain threshold, you enter the "manifestation" period during which
you begin to feel symptoms.
Fever, cramps, fatigue, diarrhea,
nausea, dehydration, and general malaise can either sneak up on you slowly,
or slam you all at once. During the manifestation period, being more than 10
seconds away from the nearest bathroom is often a bad idea. (Functional
bathrooms may be in short supply during water or utility emergencies). It's
easy to see that the best idea is not to take risks where you might be
exposed to bad drinking or cooking water.
drinking and cooking water will be critically important during any
METHODS FOR EFFECTIVE WATER TREATMENT DURING AN
First and foremost, if you already
have a distiller, use it! It is the most effective!
Although some sources indicate shorter
times, it is recommend
bringing water to a rolling boil and maintain for a minimum of 10 minutes.
For every 1000 feet above sea level, add one minute of boiling to the
initial 10 minutes. If the water pot is covered, it will shorten the
time to reach a boil. Although this method is recognized as the safest
treatment under survival or emergency conditions, it is impractical for all
but a limited amount of water. IODINE/CHLORINE
(CHLOROX) TREATMENT - when properly performed, it is effective
against almost all pathogens, including viruses, but does affect the taste
- kills all pathogens, including
- no special equipment required
- requires fuel (electricity
assumed not available)
- time consuming
- impractical for all but a
limited amount of water
- temperature sensitive
- not recommended for long term
using ordinary 2 percent tincture of iodine from the medicine chest, 3
drops per quart of CLEAR water, or 6 drops to each quart of cloudy water,
and stir thoroughly, allow water to stand for at least 30 minutes before
using or filtering for additional protection.
The addition of iodine or chlorine
is another option for rendering contaminated water drinkable. Some experts
discuss the use of chlorine in the form of bleach, which must contain (and
be so marked) 5.25% sodium hypo chlorite without soap or phosphates.
However, in addition to its immediate poisonous effects, bleach can kill
micro-organisms that a natural and vital part of your digestive system.
Iodine is preferable to bleach when one has a choice
in the matter.
If you choose to use bleach to
recommended dosages are 8 drops(1/8 tsp or .5ml) for 1 gallon of CLEAR
water; 18 drops(1/4 tsp/1.25 ml) for CLOUDY water. When storing water in
55 gallon drums or inflatable bags, use 55 ml or a stingy, 1/4 cup per 55
gallons of capacity.
Remember, these doses above are for
treated city water which has (or should) have a chlorine demand of zero.
Water obtained from other sources (lake, stream, etc.) will need more. GET A
TEST KIT for free chlorine so guess work is gone. Target your treatment at
3-5 parts per million (ppm) free chorine for city water and 5 ppm for field
For use during an emergency, it is
recommended that for drinking and cooking, this water be further filtered
(see section below) to remove any residual bacteria as well as chlorine
prior to use. Bleach loses it strength with time: products which have been
on the shelf for one year will be only 50% as effective. In that case the
amount used will have to be doubled.
Use a magic
marker to indicate date of purchase. Use an eyedropper for dosage,
mix well and allow water to stand at least 30 minutes before filtering (for
chlorine removal) and usage. Iodine crystals or tablets are inexpensive,
lightweight, compact and effective at destroying viruses and most bacteria.
Iodine in tincture or tablet form
has difficulty in dealing with the protozoa(Cryptosporidium and
Giardia) because they have a hard, egg-shell shield around them and even
straight bleach will not affect them. Iodine thus needs to be combined with
a special filtration process (described below) in order to remove all three
types of pathogens listed.
There are limitations to iodine. It
takes time to work, its effectiveness is dependent on the pH
(acidity/alkalinity) of the water, temperature (cold water reduces its
effectiveness) as well as the amount of dirt and/or silt in the untreated
water. Taste is also objectionable, but can be removed when used in
combination with the filters described below. There are possible
health risks associated with its use.
Although iodine is considered an
essential nutrient, long term ingestion is not recommended. Limitations of a
few days to a couple of weeks is suggested, with individuals having weak
immune systems on the short side of that limit. Pregnant women and
individuals with thyroid problems should consult a physician before using
iodine in this situation.