This is completely off topic, but if you enjoy
I invite you to listen.
|The Bottom Line:
||First you need to understand
which contaminants are in your water. If you are on
municipal (public) water, most water companies are required
to provide an annual water quality report.
||There are three main point of
use water treatment methods - Each process has benefits and limitations:
||Distillation is the most effective, slowest, most expensive,
and requires electricity or other energy source.
||Reverse Osmosis (RO) is
effective against most inorganic contaminants but
requires activated carbon to reduce some organics.
RO requires water pressure, is fairly slow and
typically wastes more water than it treats
||Solid Block Activated Carbon
(SBAC) is the least expensive process and does not require
electricity or high water pressure. It
significantly reduces chlorine, a wide variety of organic contaminants
like disinfection byproducts and
can be designed to reduce levels of some inorganic chemicals like
lead and arsenic. Activated Carbon is ineffective against many inorganic
contaminants like salts, iron, fluoride, aluminum, calcium,
||There are no federal
regulations regarding the effectiveness or design of water
treatment products. The FTC has created "truth
in advertising" rules, but they apparently are not enforced
except in extreme circumstances. Companies are pretty
much free to make unsupported claims to promote their products.
||Careful selection of water
treatment products certified by
WQA provides assurance that water treatment claims are
The importance of independent
certification for product evaluation
There are many thousands
products on the market that claim to provide you with the purest
water available, everything from filtration systems and distillation units to
There are, for example, over 2,500 different water filters
on the market.
How do you evaluate competing, often
contradictory, statements and determine which claims are accurate and which
advertisements are nothing more than creative writing.
When purchasing health related products, creative advertising can
be expensive for the consumer, not to mention downright dangerous.
An improperly maintained water filter can actually incubate trapped
bacteria and release them into the "filtered" water.
I personally believe that a product's performance as well as the
accuracy of its advertising literature should be tested and certified by an
independent and disinterested third party. If a product is certified by a
reputable company you can be assured that a product's ads are not misleading and
the product will perform as specified.
Two organizations provide independent certification for water purification
International and the Water
Quality Association (WQA).
||The WQA has developed a Gold Seal program to help consumers choose quality water
treatment products. The WQA tests prototype water
treatment equipment, and awards the Gold Seal only to those systems
that have met or exceeded industry standards for contaminant reduction
performance, structural integrity, and materials safety.
NSF International is a group
that certifies water treatment systems, distillation units, bottled water, water
softeners, and a number of other food preparation systems. NSF
certification means that not only do the products perform as tested, the product
advertisements are also evaluated for accuracy and truthfulness. Products
are tested on an ongoing basis to make certain that companies continue to
produce products that perform as advertised.
You need to be aware
that there are a number of different NSF standards and different levels of
compliance within the standards. NSF certification does not mean
much unless you know exactly what a specific certification standard stands
for. A water filter certified to meet NSF Standard 42 Class II for taste,
odor and chlorine and Class II for particulate matter is not equivalent
to a filter certified to meet NSF Standard 42 Class I for taste,
odor and chlorine and Class I for particulate matter and
Standard No. 53 for Health Effects. The latter filter will
remove a far wider range of contaminants -- and will also
probably cost 10 times as much as the former.
You will also
find, if you research water purification devices or bottled water, that many
companies state on their literature "Tested to NSF standards".
Tested by who? How often? Who backs up that claim? I
just visited a web site that advertised their water filter as tested and
certified in accordance with NSF/ANSI standards 42 and 53 (the NSF
logo was even displayed). I then checked the NSF on-line site
and neither the company nor the filter was listed as certified.
Unfortunately, there are even a few pitfalls to interpreting the certification reports - one of the
things to be aware of is what I call "padding the list".
“play the certification game” by paying separately to have individual VOCs tested and
even though, if the VOC Reduction group is listed, all of the
individual VOCs on the NSF table below are already covered and do not
normally need to be re-listed.
Check out the NSF site below, and use them as one of your guides to selecting a reliable
product. The site has on-line comparisons of many of the products they certify.
Mission statement - Behind the NSF Mark is an
independent, not-for-profit organization called NSF International. For over 50
years NSF has been committed to public health safety and protection of the
environment by developing standards, by providing education and by providing
third-party conformity assessment services while representing the interest of
The NSF site provides an on-line comparison of water filtration
units and bottled water products that are certified by NSF:
Selecting a Household Water Treatment System &
Drinking Water Fact Kit
||You can review certified Drinking Water
The NSF Standards that apply to water filters are # 42 and # 53. To use the guide, for water
treatment units, either enter a company name you are interested in
investigating or scroll to the bottom of the page and select either the
(counter top filter, under counter filter, etc.) or the
product standard (42, 53, etc.).
||You can look up certified bottled water
products by brand
name, product type, etc. at Bottled
Water and Packaged Ice.
Drinking Water Standards
There are currently six ANSI/NSF standards relating to water
filtration and treatment devices, each one designed for a specific type
STANDARD 42: Drinking Water Treatment Devices - Aesthetic Effects
STANDARD 44: Cation Exchange Water Softeners
STANDARD 53: Drinking Water Treatment Devices - Health Effects
STANDARD 55: Ultraviolet Microbiological Water Treatment Systems
STANDARD 58: Reverse Osmosis Drinking Water Treatment Systems
STANDARD 62: Drinking Water Distillation Systems
Things to Consider when Selecting
a Water Purification Solution:
important terms related to water treatment: |
There is some confusion about the meaning of water
purification and water disinfection.
Water Purification - "The act of cleaning by getting rid of impurities." For water treatment, this
term refers to the process of removing specified contaminants
from a water source. All effective water treatment methods will
provide some amount of purification, however, only some methods will disinfect
Water Disinfection - "Killing or removal of
microorganisms outside the body by direct exposure to chemical or physical agents or processes." For water treatment,
this term refers specifically to a purification
process that kills or removes biological contaminants (cysts, bacteria,
viruses, protozoans, etc.) from a water source. Water
that has been disinfected (by UV treatment, boiling, chlorination, micro-filtration,
etc.) may still be polluted with other contaminants that are not
affected by the disinfection treatment.
some cases, additional contaminants may actually be added to the water
by the disinfection process. For instance, the process
of chlorination nearly always adds chlorine and frequently some disinfection byproducts (trihalomethanes, like chloroform). Boiling water too long will concentrate inorganic contaminants. Sterilization
refers to the process of killing or removing all microorganisms.
The descriptions of water purification solutions on this
website are designed for people who would like to have protection at home or work
from actual or potential contaminants in the water they drink.
In order to determine which of the solutions is best for your needs you might
want to consider the following:
purified water you would like to use per day for drinking and cooking (a family
of four will probably use 4 to 8 gallons per day).
||Which contaminants are actually in your water
(and which ones might occasionally show up). The only way to know this
for sure is to request a report from your water supplier or have your
contaminants you are interested in removing (the information on the other pages
of this site should help). The plan I adopted was to go with a solution that
would provide the best protection from most of the potential contaminants (for
the lowest cost and least maintenance) - even
though most of the contaminants are not currently present in my tap water.
||The cost of
the solution you decide upon, both the initial cost (which may be high
for some filtration systems, ion exchange units, distillers, etc.) and the
ongoing costs (which might be high for distillers, bottled water, etc.).
Look at the total amount you will spend over the next 10 to 40 years based
on the amount of pure water you would like to be able to use for drinking,
cooking, washing foods, etc.
||The value of
the product. Is the product certified to perform as advertised (or in the case
of bottled water, is it certified to be free of contaminants). Does the product
provide you with safe, good tasting water at a reasonable cost. Is there
minimal maintenance required.
Treatment Methods for
Most of the methods of water treatment methods discussed below
are Point Of Use (POU) devices.
POU methods treat water at the point where
is is used - frequently at the kitchen sink. Only the water that is
actually used for drinking, cooking, beverage preparation, etc. is
treated. This has the advantage of economy - only a few hundred gallons of
water need to be treated per year instead of many thousands if all of the water
entering the home were to be treated.
Most people who use water supplied by a
municipal water company only need to worry about POU treatment to reduce harmful
contaminants, because it
is your water company's responsibility to provide biologically and chemically
safe water that has most objectionable taste and odor causing substances
removed. As you have read elsewhere on my site and in the local news, this
is unfortunately not always the case. Most people using public water do not need to employ
Point of Entry treatment devices or the more expensive POU devices like distillation and reverse osmosis. It
is important, though, to obtain and read the annual Water Quality Report that the water
company is required to make available to you. The contaminants most people
using public water would be liable to experience at harmful or unacceptable
Residual disinfectants (chlorine and/or
chloramine, for example) added to keep water safe during distribution.
Disinfection byproducts, like the
Lead (as discussed elsewhere, many
homes leach lead into the water from pipes and/or fixtures).
Brief, accidental contamination by
microbes (E. coli, giardia, cryptosporidia, etc.) or other contaminants.
If you live in an agricultural region,
unacceptable levels of nitrates or organic compounds (even if they are
below regulated levels).
Point Of Entry (POE),
or whole house water treatment (where all water entering the home is treated) is
indicated when the water has problems that affect all areas of the home.
The most common example is a water softening ion exchange system that removes
calcium and magnesium ions (and some other ions) from the water. Hard
water, while quite healthy to drink, can cause scale buildup in pipes and on
fixtures, interfere with the effectiveness of soap, and shorten the life of
appliances, like dish washers and hot water heaters. Other POE water
treatment systems are designed to remove iron and manganese, adjust pH levels,
add chlorine or other disinfectant, etc.
People using water from a private
well, spring, or surface source are most likely to require POE treatment.
Check the Water Treatment Table for some POE
methods of treatment (particularly the notes toward the bottom). A high quality POU
treatment system should also be considered if you have a well or use water from
a spring or surface source, because each type of POE treatment generally removes
only one contaminant type (the one or two POE treatment methods someone might
use would only remove
the most obvious, annoying, or dangerous contaminants). Other
contaminants that might be present like lead (from the home's plumbing and
pipes) and chlorine residue (if the water is disinfected) would best be removed
by a POU device. I discuss those point of entry (whole house) systems typically
used with municipal water (filters, ion exchange softeners and no-salt
In an emergency, boiling
is the best way to disinfect water that is unsafe because of the presence
of protozoan parasites, bacteria or viruses.
If the water is cloudy, it should be
filtered before boiling. Filters designed for use when camping,
coffee filters, towels (paper or cotton), cheesecloth, or a cotton plug
in a funnel are effective ways to filter cloudy water.
Place the water in a clean container and bring it
to a full boil and continue boiling for at least 3 minutes (covering the
container will help reduce evaporation). If you are more than
5,000 feet above sea level, you must increase the boiling time to at
least 5 minutes (plus about a minute for every additional 1,000 feet).
Boiled water should be kept covered while cooling.
The advantages of Boiling Water include:
that might be lurking in your water will be killed if the water is boiled long enough.
will also drive out some of the Volatile Organic Compounds (VOCs) that might also be in the water.
This method works well to make water that is contaminated
with living organisms safe to drink, but because of the inconvenience, boiling is
not routinely used to treat drinking water except in emergencies.
The disadvantages of Boiling Water include:
should not be used when toxic metals, chemicals (lead, mercury, asbestos, pesticides, solvents,
etc.), or nitrates have contaminated the water.
||Boiling may concentrate any harmful
contaminants that do not vaporize as the relatively pure water vapor boils
||Energy is needed to boil the water,
so it may be difficult to boil water in an emergency.
To remove impurities from water by distillation, the
water is usually boiled in a chamber causing water to vaporize, and the pure (or mostly pure) steam
non volatile contaminants behind. The steam moves to a different part of the
unit and is cooled until it condenses back into liquid water. The resulting distillate drips into a
Salts, sediment, metals -
anything that won't boil or evaporate - remain in the distiller and must be
removed. Volatile organic compounds (VOCs) are a good example of a contaminant that
will evaporate and condense with the water vapor. A vapor trap, carbon filter, or other device must be used
along with a distiller to ensure
a more complete removal of contaminants.
The advantages of Distillation include:
|| A good
distillation unit produces very pure water. This is one of the few practical ways to remove heavy metals, nitrates, chloride, and other salts that carbon filtration can not remove.
|| Distillation also
removes pathogens in the water, mostly by killing and leaving them behind when the water vapor evaporates. If the water is boiled, or heated just short of boiling, pathogens would also be killed.
As long as the distiller is kept clean and is working properly the high quality of treated water will be very consistent regardless of the incoming water - no drop in quality
filter cartridges to replace, unless a carbon filter is used to remove volatile organic compounds.
The disadvantages of Distillation include:
||Distillation takes time to purify the water,
It can take two to five hours to make a gallon of distilled water.;
||Distillers requires periodic cleaning of the boiler, condensation compartment, and storage tank.
||Countertop Distillation is one of the more expensive home water treatment methods, using $0.25 to $0.35 of electrical energy per gallon of distilled water produced -
depending on local electricity costs. The
cost of ownership is high because you not only have the initial cost of the
distillation unit to consider, but you also must pay for the electrical energy
for each gallon of water produced. If it cost you $0.25 to distill each gallon,
and you purified 10 gallons per week, you would pay $130 for your 520 gallons of
distilled water each year.
||Most home distillation units require electricity, and will
not function in an emergency situation when electrical
power is not available.
You might want to check NSF
International to see if the distillation system you are interested
in purchasing is certified.
I have had a number of questions asking if
distilled water (or water with most of the ions removed by reverse
osmosis or deionization) are either bad for a person's health or
beneficial for health relative to purified water that still contains
ions (usually calcium and magnesium). Click here
to view my
response to that question.
Reverse Osmosis (RO):
pressure is used to force water molecules through a membrane that has extremely tiny
pores, leaving the larger contaminants behind. Purified water is collected from the "clean" side of the
membrane, and water containing the concentrated contaminants is flushed down the
drain from the "contaminated" side. The average RO system is a unit consisting of a
sediment/chlorine pre filter, the reverse-osmosis membrane, a water storage tank, and
an activated-carbon post filter. They cost from about $150 to over $1,500
for point of use systems.
The advantages of Reverse Osmosis include:
osmosis significantly reduces salt, most other inorganic material
present in the water, and some organic compounds.
With a quality carbon filter to remove any organic materials that get through the
filter, the purity of the treated water approaches that produced by distillation.
||Microscopic parasites (including viruses)
are usually removed by properly functioning RO units, but
any defect in the membrane would allow these organisms to flow undetected
"filtered" water - they are not recommended for use on
biologically unsafe water.
slower than a carbon or sediment water filter, RO systems can typically purify more water per day
than distillers and are less expensive to operate and maintain.
||Reverse Osmosis systems also do not use
electricity, although because they require relatively high water pressure to
operate, they may not work well in some emergency situations.
The disadvantages of Reverse Osmosis include:
of Use RO units make only 12 - 24 gallons of treated water a day for drinking or cooking
- which is ok for most homes since the treated water is stored
in a tank for use.
waste water. Two to four gallons of "waste" water are flushed down the drain for
each gallon of filtered water produced.
||Some pesticides, solvents and other volatile organic chemicals
(VOCs) are not completely removed by RO.
A good activated carbon post filter is
recommended to reduce these contaminants.
||Many conditions affect the RO membrane's efficiency in reducing the amount of contaminant in the water.
These include the contaminant concentration, chemical properties of the contaminants, the membrane type and condition, and operating conditions (like pH, water
temperature, and water pressure).
||Although RO filters do not use electricity, they depend on a relatively high water pressure to force the
water molecules through the membrane. An electric booster pump can
be used to increase water pressure if needed. In an emergency situation where water pressure has been lost, these systems
will not function.
* However, if a high quality activated carbon
filter is used for the post filter, it could be disconnected and
used to siphon water through in an emergency to reduce
||RO systems require maintenance. The pre and post
filters and the reverse osmosis membranes must be
changed according to the manufacturer's recommendation,
and the storage tank must be cleaned periodically.
membranes are not easily detected, so it is hard to tell if the system is functioning normally
You might want to check NSF
International to see if the Reverse Osmosis system you are
interested in purchasing is certified.
|| A reverse-osmosis system is a good treatment
option for people who have unacceptably high levels of dissolved inorganic
contaminants in their drinking water which can not be removed effectively or
economically by other methods. Water from shallow wells in agricultural areas
that contains high nitrate levels is a good example of a situation where RO would make sense. Most people, however, who are using municipal water water that is subject to
EPA regulations usually have acceptably low levels of nitrates. Maximum nitrate
levels should be able to be determined by requesting a water quality report from
your local water provider.
I have received a number of questions asking if
distilled water is either bad for a person's health or
beneficial for health relative to purified water that still contains
ions (usually calcium and magnesium). This question pertains
equally well to water from a RO system, because most ions have been
removed by the treatment. Click here
to view my
response to that question.
The topic of water
filters is complicated because there are so many models available (over
2,500 different models manufactured by more than 500 companies), and because
there are so many types of filtration strategies and combinations of strategies
used. The basic concept behind nearly all filters, however, is fairly simple.
The contaminants are physically prevented from moving through the filter either
by screening them out with very small pores and/or, in the case of carbon
filters, by trapping them within the filter matrix by attracting them to the
surface of carbon particles (the process of adsorption).
||There are three main types of filters:
and Activated Carbon filters are discussed below, and sometimes they are combined into a single unit.
The third type, Reverse Osmosis will be considered as
a separate topic.
You will read about micron or sub micron filtration. This is a measure of
how good the filter is at removing particles from the water - smaller is better.
A micron is a unit of measure - one micron is about 1/100 the diameter of a
human hair. A filter that removes particles down to 5 microns will produce fairly clean-looking water, but most of the water parasites, bacteria, cryptosporidia, giardia, etc. will pass through the pores. A filter must trap
particles one micron or smaller to be effective at removing cryptosporidia or
giardia cysts. Viruses can not be effectively removed by any filtration method.
In theory, reverse osmosis will remove viruses, but a
small flaw in the membranes would allow viruses to pass
undetected into the 'filtered' water. Click here
view a figure that compares the relative size of several biological contaminants with the pore size of some common filters.
||A benefit of all home filtration systems is that they are passive. That is, they do not require
electricity to filter the water, and normal home water pressure is used to
force the water though the filter. The only routine maintenance required is periodic
replacement of the filtration element. As long as the cost of the replacement
filter elements is reasonable, owning a even a high-end water filter
can be very inexpensive if you look at the long term costs
and compare it with
||Sediment Filters - Solid Particles are
Strained Out of the Water:
Fiber Filters: These filters contain cellulose, rayon or some other
material spun into a mesh with small pores. If you take a piece of cloth and
pour water containing sand through it you will get the picture. Suspended
sediment (or turbidity) is removed as water pressure forces water through
tightly wrapped fibers. Some small organic particles that cause disagreeable odors and taste
may also be removed. These filters come in a variety of sizes and meshes
from fine to coarse, with the lower micron rating being the finer. The finer the filter, the more particles are trapped and the more often the filter
must be changed.
||Fiber filters are often used as pre-filters to reduce the suspended contaminants that could clog carbon
or RO filters.
|Fiber filters will not remove contaminants that are
dissolved in the water, like chlorine, lead, mercury, trihalomethanes or other organic
Ceramic Filters: Ceramic filters are much like fiber filters and use a
process where water is forced through the pores of a ceramic filtration
media. This provides mechanical filtration only. This type of filter can
reduce asbestos fibers, cysts (if the pores are one micron or smaller), some bacteria (with pore sizes in the 0.2 - 0.8 micron range**) and other
||Ceramic filters will not remove contaminants that are dissolved in the water, like chlorine, lead, mercury, trihalomethanes or other organic
compounds, nor will they remove viruses. These filters may be used as a back-end to an activated carbon
filter to provide a more thorough removal of contaminants.
NOTE - NSF does not certify filters for bacterial removal, and I am
unaware of any independent certification process for their removal.
Activated carbon (AC) is particles of carbon that have been
treated to increase their surface area and increase their ability to adsorb a
wide range of contaminants - activated carbon is particularly good at adsorbing organic compounds. You will find two basic kinds of carbon filters Granular
Activated Carbon (GAC) and Solid Block Activated Carbon (SBAC).
Contaminant reduction in AC filters takes
place by two processes, physical removal of contaminant
particles, blocking any that are too large to pass through the
pores (obviously, filters with smaller pores are more effective),
and a process called adsorption by which a variety of
dissolved contaminants are attracted to and held
(adsorbed) on the surface of the carbon particles. The
characteristics of the carbon material (particle and pore size,
surface area, surface chemistry, density, and hardness) influence
the efficiency of adsorption.
AC is a highly porous material; therefore, it has an
extremely high surface area for contaminant adsorption. One reference mentions
" The equivalent
surface area of 1 pound of AC ranges from 60 to 150 acres (over 3
football fields)". Another article states, "Under
a scanning electron microscope the activated carbon looks like a porous
bath sponge. This high
concentration of pores within a relatively small volume produces a
material with a phenomenal surface area: one tea spoon of activated
carbon would exhibit a surface area equivalent to that of a football
field." ( estimates of surface area vary from different
sources - RJ)
AC is made of tiny clusters of carbon atoms stacked upon one another.
The carbon source is a variety of materials, such as peanut shells,
coconut husks, or
coal. The raw carbon source is slowly heated in the absence of air to
produce a high carbon material. The carbon is activated by passing
oxidizing gases through the material at extremely high temperatures. The
activation process produces the pores that result in such high
adsorptive properties. An article about Activated
Carbon states that "Activated carbon is one of the best
tools which can be used to reduce risks to human health and provide an
aesthetically pleasing product at reasonable cost."
The article also describes how AC works and has some of the best scanning electron microscope
pictures of actual AC granules I have seen.
The adsorption process depends on the following factors: 1) physical
properties of the AC, such as pore size distribution and surface area;
2) the chemical nature of the carbon source, or the amount of oxygen and
hydrogen associated with it; 3) chemical composition and concentration
of the contaminant; 4) the temperature and pH of the water; and 5) the
flow rate or time exposure of water to AC. Interesting articles:
What is Activated Carbon,
The effectiveness of carbon filters to reduce contaminants is affected by the factors affecting adsorption
listed above and three additional characteristics of the
filter, contact time between the water and the carbon material, the amount of carbon in the filter, and pore size.
The length of contact time between the water and the carbon material, governed by the rate of water
flow and the amount/volume of activated carbon, has a significant effect on adsorption of contaminants. More contact time results in greater adsorption.
amount of carbon present in a cartridge or filter affects the amount and type of contaminant removed. Less carbon is required to remove taste- and odor-producing chemicals than to remove trihalomethanes.
Pore size characteristics will be discussed in greater detail on
the GAC and SBAC pages, but GAC filters contain loose granules of
activated carbon while in SBAC filters, the activated carbon is in the
form of very small particles bound into a solid, matrix with very small
Because of the filter characteristics discussed above, the
most effective Point of Use activated carbon filters are large
SBAC filtration systems, and the least effective
are the small, pour-through pitcher filters.
||Activated carbon filter cartridges will, over time, become less
effective at reducing contaminants as the pores clog with
particles (slowing water flow) and the adsorptive surfaces in the pores become
filled with contaminants (typically not affecting flow rate). There
is often no noticeable indication that a carbon filter is no longer removing
contaminants, so it is important to replace the cartridge according to
the manufacturer's instructions.
The overall water quality (turbidity or presence of other contaminants) also affects the capacity of
activated carbon to adsorb a specific contaminant.
||It is important to note, particularly
when using counter-top and faucet-mount carbon filtration systems, that hot
water should NEVER be run through a carbon filter. I have seen warnings
about possible damage to the filter from hot water. Perhaps more importantly, hot
water will tend to release trapped contaminants into the water flow
potentially making the water coming out of the filter more contaminated than
the water going in.
Granular Activated Carbon (GAC):
In this type of filter, water flows through a bed of
loose activated carbon granules which trap some particulate matter and
chlorine, organic contaminants, and undesirable tastes and odors. The three main problems associated with GAC
filters are: channeling,
dumping, and an inherently large pore size.
Most of the disadvantages discussed below are not the fault of the
activated carbon filtration media, rather, the problem is the design of
the filters and the use of loose granules ofactivated carbon.
|| The advantages of GAC filters include:
GAC filters are primarily used for aesthetic water treatment, since they
chlorine and particulate matter as well as improve the taste and odor of the
granules of carbon do not restrict the water flow to the extent of Solid Block Activated Carbon (SBAC)
filters. This enables them to be used in situations, like whole
house filters, where maintaining a good water flow rate and
pressure is important.
||Simple, economical maintenance. Typically an inexpensive filter cartridge needs to be changed
every few months to a year, depending on water use and the
||GAC filters do not require electricity, nor do they waste water.
||Many dissolved minerals are not removed by activated carbon. In the case of calcium,
magnesium, potassium, and other beneficial minerals, the taste of the water can be
improved and some (usually small) nutrient value can be
gained from the water.
The bottom line is that GAC filters are effective and valuable water
treatment devices, but their limitations always need to be
considered. A uniform flow rate, not to exceed the manufacture's
specifications, must be maintained for optimal performance, and the
filter cartridge must be changed after treating the number of gallons
the filter is rated for.
|| The disadvantages of GAC filters include:
||Water flowing through the filter
is able to "channel" around the carbon granules
and avoid filtration. Water seeks the path of
least resistance. When it flows through a bed of loose
carbon granules, it can carve a channel
where it can flow freely with little resistance. Water
flowing through the
channel does not come in contact with the
filtration medium. The water continues to flow,
you do not realize that your filter has failed - you get water,
but it is not completely filtered.
||Pockets of contaminated water can
form in a loose bed of carbon granules.
With changes in water pressure and flow rates,
these pockets can collapse, "dumping"
the contaminated water
through the filter into the "filtered" flow.
||Since the carbon granules are
fairly large (0.1mm to 1mm in one popular
pitcher filter), the effective
pore size of the filter is relatively large
(20 - 30
microns or larger). GAC filters, by themselves, cannot
significantly reduce bacterial contamination.
water should NEVER be run through a carbon filter
||Also, if you think of a bed of
charcoal that traps an occasional bacterium, picks up a
bit of organic material, and removes the chlorine from
the water, you can see how these filters might become
for the bacteria they trap. You will see warnings about GAC filters
suggesting you run water through them for a few minutes
each morning to flush out any bacteria.
If you are considering purchasing a GAC filter be sure to ask the
representative about what they recommend you do about this potential problem
(I was told by one sales person, that if the filter was not going to be
for a few days, I should remove the filtration element, place it in a
plastic bag, and store it in the refrigerator until I
Unless the filter plugs up or
you notice an odor in the "filtered water", it may be difficult to know when the
filter has become saturated with contaminants and ineffective.
That is why it is necessary to change filter cartridges according to
the manufacturer's recommendation.
||Solid Block Activated Carbon (SBAC):
Activated carbon is the primary raw
material in solid carbon block filters; but instead of carbon
granules comprising the filtration medium, the carbon has been
specially treated, compressed, and bonded to form a uniform matrix. The effective
pore size can be very small (0.5 - 1 micron). SBAC, like all filter cartridges, eventually
become plugged or saturated by contaminants and must be
changed according to manufacturer's specifications.
Depending on the manufacturer, the filters can be designed to
better reduce specific contaminants like arsenic, MTBE, etc. (an
|| The advantages of SBAC filters include:
||Provide a larger surface area for adsorption to take
place than Granular Activated Carbon
(GAC) filters for better contaminant reduction.
||Provide a longer contact time
with the activated carbon for more complete contaminant reduction.
||Provide a small pore size to
physically trap particulates. If the pore size is small
enough, around 0.5 micron or smaller, bacteria that
become trapped in the pores do not have enough room to
multiply, eliminating a problem common to GAC
||Completely eliminate the channeling and dumping problems associated with GAC filters.
||SBAC filters are useful in
emergency situations where water pressure and
electricity might be lost. They do not require
electricity to be completely effective, and
water can even be siphoned through them.
||SBAC filters do not waste water like reverse osmosis.
||Many dissolved minerals are not
removed by activated carbon. In the case of
calcium, magnesium, potassium, and other beneficial
minerals, the taste of the water can be improved, and
some (usually small) nutrient value can be
gained from the water.
||Simple, economical maintenance.
Typically an inexpensive filter cartridge needs to
be changed every few months to a year, depending on water use and the
||This combination of features
provides the potential for greater adsorption of many
different chemicals (pesticides, herbicides, chlorine,
chlorine byproducts, etc.) and greater particulate
filtration of parasitic cysts, asbestos, etc. than many
other purification process available. By using
other specialized materials along with specially
prepared activated carbon, customized SBAC filters can
be produced for specific applications or to achieve
greater capacity ratings for certain contaminants
like lead, mercury, arsenic, etc.
|| The disadvantages of SBAC filters
filters, like all activated carbon filters, do not
naturally reduce the levels of soluble salts (including
nitrates), fluoride, and some other potentially harmful
minerals like arsenic (unless specially designed) and
cadmium. If these contaminants are present in your
water, reverse osmosis would usually be the most
economical alternative followed by distillation.
water should NEVER be run through a carbon filter
||As SBAC filters remove contaminants from the water they gradually lose effectiveness until they are no
longer able to adsorb the contaminants. There is no easy way to
determine when a filter
is nearing the end of its effective life except that the 'filtered' water eventually begins to taste
and smell like the
unfiltered water. The manufacturer's guidelines for changing filter cartridges should always be followed.
To ensure that marketing claims are accurate, check NSF
International to see if the SBAC filtration system you are
interested in purchasing is certified to significantly reduce the
contaminants you are concerned about.
An example of a certified list of
contaminants significantly reduced by a high-end SBAC filtration
system (** at 200 percent of capacity - that's after filtering
twice the rated volume of the filter**):
For Standard 042 -
Chlorine Reduction, Class I
(actual chlorine reduction 99.9%)
Particulate Reduction, Class I
(actual particulate reduction down to 0.5
(actual chloramine reduction greater than 96%)
Taste and Odor Reduction
For Standard 053 -
contaminants of health concern and measured percent reduction
Asbestos Reduction >99%
Chlordane Reduction >99.8%
Cyst Reduction 99.9%
Lead Reduction >98%
Mercury Reduction >99.3% (pH 8.5) >91.4 (pH
MTBE Reduction 96.6%
PCB Reduction >98%
Toxaphene Reduction >93%
TTHM Reduction (Trihalomethanes) >99.8%
Turbidity Reduction >99%
VOC Reduction (volatile organic chemical) Reduction -
you will see a
long list of specific VOCs (individual percent
reduction for the various
VOCs can be found on the product certification sheet
most are 98-99% or more).
A few SBAC filtration systems
have been certified for arsenic reduction:
What about the inexpensive GAC pitcher filters and faucet
mount filters? How effective are they for your water purification needs?.
The answer to that question depends on what your water treatment goals
are and the amount of filtered water you plan to use. The most
popular brands are GAC filters that will sometimes also contain granules of an ion
exchange medium (you can see and hear the granules rattling around).
||They do reduce the level of some contaminants of health concern and thus
are better than nothing.
They are very limited in the type and number of contaminants
they remove, typically chlorine and perhaps
lead, copper, and/or cysts are reduced.
|| At about $5 - $10 for a filter cartridge capable of treating about 35 -
40 gallons, your filtered water will cost about
$0.14 - $0.25 per gallon ( $58 - $90 per year if you use 35 gallons per
month). If you are using (or would like to use) much more than a gallon per day, and/or would
like to remove more than a minimum number of contaminants, you should probably
examine other options.
|| Since they contain a very small amount of very loose GAC granules,
they CAN NOT be considered effective
treatments for most biological contaminants or chemical contaminants of
health concern. The pitcher filters which contain a microfilter are typically
certified to reduce cysts. All of these filters are mostly designed to improve the aesthetics
of drinking water (taste & odor improvement) and reduce levels of a limited
number of harmful contaminants. They are subject to possible bacterial growth channeling,
and all the other problems of larger GAC filters.
How about effectiveness of the Solid Carbon Block faucet mount filters?
||The solid carbon block faucet mount filters are more effective than GAC
filters in reducing contaminants.
filters, by nature, are quite small, though, and because filter
effectiveness is dependent on contact time of the
water with the filter media, a larger, high-quality solid carbon block filter will be
more effective at reducing contaminants at the ame flow rate. The
difference is size can be striking - 4 ounces of activated carbon for a faucet mount filter
vs. 32 ounces for a high-end filter, over 7 times more filter media.
the pitcher filters, the replacement cartridges for faucet mount filters
tend to be relatively more expensive
(typically $0.14 - $0.25 per gallon) compared to a high-quality solid block activated
carbon replacement filter which will filter water for about $0.08 per gallon. Using
2 gallons of filtered water per day would cost between $100 and $180 a
year to replace
4 - 5 ounce faucet mount cartridges and about $60 to replace a 32 ounce high-end
filter solid block activated carbon filter.
Did the water
in the bottle you just purchased really come from the beautiful spring shown on
the label? How can you be sure the water in the bottle is any cleaner or safer
than your tap water? How does the cost, both short term and long term, compare
with other water purification options?
Bottled water is simply water from some source
that a company (or in the case of water vending machines, the consumer)
has placed in a bottle for resale. Bottled water can have minimal
(or no) processing - as in natural spring or mineral water, or it can be
completely filtered and demineralized to nearly pure water and then have
minerals added back to improve the taste.
||But, how can you be sure the water
in the bottle you purchased is any cleaner or safer than your tap water?
Just like any of
the other water treatment solutions, you will find reputable companies that
provide a safe, quality product, and you will find companies that fill their bottles using the local, municipal water
with marginal treatment.
There are 2 regulatory organizations, 1 trade association, and 1
independent certification organization, which contribute to ensuring the safety and quality of bottled water.
(A NRDC Discussion of Bottled Water)
Issues and Alternatives
According to the University of
Illinois at Urbana-Champaign, College of Agriculture, Cooperative Extension
Service, bottled water is regulated at the federal level, and in some cases, at
the state level. Bottled water suppliers who are members of the International
Bottled Water Association (IBWA) regulate themselves and are given unannounced
inspections by NSF International. Bottled water companies can also
have their product certified by NSF International.
Federal standards - Bottled water is
regulated by the Food and Drug Administration (FDA), which requires
manufacturers to submit samples regularly for testing. In the United States, the
concentration of contaminants found in bottled water must be less than the
"allowable levels" set by the FDA which are essentially the same as the maximum
contaminant levels that the EPA requires municipal water supplies to meet.
State standards - Individual states must enforce the federal bottled
water regulations, but they can also pass stricter standards.
International Bottled Water
Association. The bottled water industry regulates itself through the
International Bottled Water Association (IBWA).
Bottled water FAQs. The
IBWA sets manufacturing requirements, which help to ensure that bottlers meet
FDA health standards. Bottled water producers who are members of IBWA are
inspected annually by an independent laboratory, the National Sanitation
Foundation. Through unannounced inspections, members are evaluated on compliance
with the IBWA's performance requirements and FDA Quality Standards.
bottled water manufacturers are members of the IBWA. Of the 475 bottling plants
in the United States (in 1994), 250 are members. The label may indicate whether
a bottled water comes from a member company.
You might want to check NSF
International to see if the bottled water you are interested in
purchasing is certified. The NSF Bottled Water Certification Program is an annual, voluntary certification process that includes both extensive product evaluations as well as on-site audits of bottling facilities.
The NSF testing program provides for annual unannounced plant inspections covering every aspect of a bottler's operation, from the source of the water, through the disinfection and treatment process, and including the container closure process.
The company also performs extensive product testing for over 160 chemical, inorganic, radiological, and microbiological contaminants.
An interesting article from Scientific American magazine on bottled
Advantages of Bottled Water include:
The bottled water industry would like the public to believe that bottled water is
more pure and safer than tap water and
water produced by other treatment methods. The actual
quality of bottled water depends on the bottling company, and
most is usually good.
High quality home water treatment methods (filtration, reverse
osmosis, and distillation) can usually produce water of equal
or better quality more economically, however.
The disadvantages of Bottled Water include:
||Bulk Bottled: Bottled
water costs anywhere from $0.25 a gallon for water from
a vending machine machine to $0.50 for generic water jugs you purchase in a store to $1.00 -
$1.50or more for water delivered to your home.
If you purchase 10 gallons of
bottled water a week, you will spend $260 (at$.50/gal), $520 (at $1.00/gal),
$780 (at $1.50/gal), or more every year.
||Individual Bottles: Many
people are willing to
pay extraordinary prices for the availability and convenience of of certain
products. That 16 ounce bottle of "designer water" you just purchased at the gas
station for $0.69 costs $5.52 per gallon, probably more than twice as much per gallon as your gas!
Purchasing just one 16 oz bottle
per day (at $0.69 per bottle) will cost you
year - that's for a total of 45
were to take a minute to fill your own well-cleaned bottle with filtered or distilled water, however, a 16 oz bottle of water would
cost perhaps1 - 2 cents a day, or less than $7.30 per
||Inconvenience - Using bottled water
requires moving and storing jugs or bottles of water. Water weighs
about eight pounds per gallon, or about 40 pounds per five gallon bottle.
Failure of a small valve can lead to a big mess, as I discovered
after arriving home one evening after a long day at work
to find 3 gallons of water soaking into the
||Negative Environmental Impact -
Producing bottles uses resources, and unless they are reused or recycled,
they cause a waste disposal problem. Recycle or reuse the
empty bottles, if at all possible. Transporting bottles of
water from the bottler to stores or homes also uses resources.
||Keep Your Bottle Clean - According to the University of
Illinois at Urbana-Champaign, College of Agriculture, Cooperative Extension
Service, "If you choose bottled water after
careful investigation, keep in mind that all of your hard work will go to waste if you aren't careful about
keeping your bottled water clean. You have to be faithful in maintaining the
hygiene of your bottled water, or you may increase your exposure to bacteria.
Bacteria grow best in warm, moist areas. The wet, warm, threaded cap of an
unrefrigerated bottle of water is a perfect place for bacteria to grow; they
will begin to grow as soon as you break the seal. If ingested, these bacteria
can cause gastrointestinal problems and other health risks. The key is to
maintain the cleanliness of your bottles and store them properly. Follow these
Store opened bottles in a refrigerator at a temperature above freezing but
less than 50 degrees Fahrenheit.
Wipe the seal with a clean cloth after each use.
||Avoid any type of buildup in the bottle cap.
||If your bottle is
refillable, make sure it is well-cleaned and rinsed before refilling.
possible, recycle the old bottle and obtain a fresh, sterile, sealed bottle."
5 gallon water dispensers
must also be kept meticulously clean to prevent bacteria from growing in the
reservoir area and bubbling into the bottle. Safety & Health Services
recommendations. (pdf file)
|Ultra Violet Light:
through a clear chamber where it is exposed to Ultra Violet (UV) Light. UV light
effectively destroys bacteria and viruses. However, how well the
UV system works depends on the energy dose that the organism absorbs.
the energy dose is not high enough, the organism’s genetic material
may only be damaged rather than disrupted.
The advantages of using UV include:
||No known toxic or significant nontoxic byproducts introduced.
||Removes some organic contaminants,
specifics are difficult to locate.
||Leaves no smell or taste in the treated water.
||Requires very little contact time (seconds versus minutes for chemical
||Improves the taste of water because some organic contaminants and nuisance microorganisms are destroyed.
||Many pathogenic microorganisms are killed or rendered inactive.
||Does not affect minerals in water.
The disadvantages of using UV include:
||UV radiation is not suitable for water
with high levels of suspended solids, turbidity, color, or
soluble organic matter. These materials can react with UV
radiation, and reduce disinfection performance. Turbidity makes
it difficult for radiation to penetrate water and pathogens can be 'shadowed',
protecting them from the light.
||UV light is not effective against any
non-living contaminant, lead, asbestos, many organic chemicals, chlorine, etc.
||Tough cryptosporidia cysts
are fairly resistant to UV light.
||Like Ozone, UV light can degrade some
organic compounds into equally harmful byproducts.
Requires electricity to operate. In an emergency situation, when the power is out, the purification will not
||UV is typically
used as a final purification stage on some filtration systems. If you are
concerned about removing contaminants in addition to bacteria and viruses, you
would still need to use a quality carbon filter or reverse osmosis system in
addition to the UV system.
|Water Softeners and
Water softeners operate on the ion exchange
process (specifically a cation exchange process where + ions are exchanged).
In this process, water passes through a media bed, usually sulfonated polystyrene beads. The beads are supersaturated with
sodium (a positive ion). The ion exchange process takes place as hard water passes through the softening material. The hardness minerals
(positively charged Calcium and Magnesium ions) attach themselves to the resin beads while sodium on the resin beads is released simultaneously into the water.
When the resin becomes saturated with calcium and magnesium, it must be recharged. The recharging is done by passing a
concentrated salt (brine) solution through the resin. The concentrated sodium replaces the
trapped calcium and magnesium ions which are discharged in the waste water. Softened water is not recommended for watering plants, lawns, and gardens due to its
elevated sodium content.
Several factors govern the efficiency of a cationic softener:
Type & quality of resin used;
Amount of salt per cubic foot of resin for regeneration;
Brine concentration in the resin bed during regeneration;
Brine flow rate through the resin bed (contact time) during regeneration;
Raw water hardness;
Raw water temperature - softeners perform better at higher temperatures; and
Optimal flow rate of hard water through the resin bed.
Although not as commonly used, potassium chloride can be used to create the salt
brine for softeners designed to use KCl. In that case potassium rather than sodium is exchanged with calcium and magnesium. Before selecting an ion exchange water softener, test water for hardness and iron content. When selecting a water softener, the regeneration control system, the hardness removal capacity, and the iron limitations are three important elements to consider.
information on Hard Water and Softening.
The advantages of water softeners include:
||The nuisance factor of hard water is reduced.
||Some other other cations like barium, radium and iron may be reduced depending on the manufacturer's
The disadvantages of water softeners include:
process of regenerating the ion exchange bed dumps salt water into the
||The elevated sodium concentration of most softened water can affect the taste
and may not be good for
people on low sodium diets, although sodium
concentrations are typically quite low relative to sodium levels in
||Cation exchange does not reduce the level of anions (like nitrates), or biological
(bacteria, viruses, cysts) ; nor does the process reduce the levels
most organic compounds.
||Typically, approximately 50 gallons of rinse water per cubic foot of resin is
required to totally remove hardness and excess salt from the
resin after each
This page describes
Traditional Water Softeners and
Non-salt Water Conditioners
use both Cation and Anion Exchange to exchange both positive and
negative ions with H+ or OH- ions respectively, leading to completely
demineralized water. Deionizers do not remove uncharged compounds
from water, and are often used in the final purification stages of
producing completely pure water for medical, research, and industrial
A potential problem with deionizers is that colonies of microorganisms can become established and proliferate on the nutrient-rich surfaces of the resin. When not regularly sanitized or regenerated, ion-exchange resins can contaminate drinking water with bacteria.
KDF filters employ a matrix
(generally small granules) of a zinc/copper alloy, which are claimed to eliminate
contaminants from water by utilizing electrochemical oxidation reduction. Claims include
the ability KDF to:
||Remove chlorine (actually changes free chlorine to a less active form).
||Kill algae and fungi.
growth in the filter.
||Remove hydrogen sulfide, iron, lead, cadmium,
aluminum, mercury, arsenic and other inorganic compounds.
||Partially reduce hardness.
||Remove hydrogen sulfide, iron, lead, cadmium,
aluminum, mercury, arsenic and other inorganic compounds.
Zinc and copper are the preferred metals used in the KDF alloy since both are
relatively good reducing agents with respect to common inorganic contaminants
(such as chlorine), and both can be tolerated in solution in moderate
concentrations without adverse side effects.
The advantages of KDF filters include:
KDF is the only filter medium I am aware of that claims to
remove contaminants from running hot water (unlike carbon
filters where hot water can release trapped contaminants into the water stream). This makes them ideal
for use in the shower.
The filters change the free chlorine some people are allergic
to into a form (zinc chloride) that is much more easily tolerated.
The disadvantages of KDF filters
a web site
from a chemist that casts
doubt on some the contaminant reduction claims made for KDF (or at least on the
chemical processes put forward to explain the reduction). I have
searched for independent confirmation of claims, and there is remarkably little
available on the Internet for a product that is so widely used.
||KDF filters do not, by themselves, remove
organic chemicals (pesticides, disinfection byproducts, MTBE, etc.), or parasitic cysts
(giardia and cryptosporidium). If you are concerned about removing any of these contaminants, other strategies will be
needed in addition to the KDF media.
||KDF filters need to be backwashed
periodically with hot water to remove the insoluble
contaminants. This method wastes many gallons of hot water and
there is no way to prevent dislodged pollutants from coming out
later with the supposedly filtered water.
The formation of oxygen into ozone occurs with the use of energy. This process is carried out
by an electric discharge field as in the CD-type ozone generators (corona discharge simulation
of the lightning), or by ultraviolet radiation as in UV-type ozone generators (simulation of the
ultra-violet rays from the sun). In addition to these commercial methods, ozone may also be
made through electrolytic and chemical reactions.
Ozone is a naturally occurring component of fresh air. It can be produced by the ultraviolet
rays of the sun reacting with the Earth's upper atmosphere (which creates a protective ozone
layer), by lightning, or it can be created artificially with an ozone generator.
molecule contains three oxygen atoms whereas the normal oxygen molecule contains only two.
Ozone is a very reactive and unstable gas with a short half-life before it reverts back to
oxygen. Ozone is the most powerful and rapid acting oxidizer man can produce, and will
oxidize all bacteria, mold and yeast spores, organic material and viruses
given sufficient exposure.
The advantages of using Ozone include:
Ozone is primarily a disinfectant that effectively
kills biological contaminants.
Ozone also oxidizes and precipitates iron,
sulfur, and manganese so they can be filtered out of solution.
Ozone will oxidize and break down many organic chemicals including many that cause odor and taste problems.
Ozonation produces no taste or odor in the water.
Since ozone is made of oxygen and reverts to pure
oxygen, it vanishes without trace once it has been used. In the home,
this does not matter much, but when water companies use ozone to disinfect the water
there is no residual disinfectant, so chlorine or another disinfectant must be added
to minimize microbial growth during storage and distribution.
The disadvantages of using Ozone include:
undesirable byproducts that can be harmful to health
if they are not controlled (e.g., formaldehyde and bromate).
process of creating ozone in the home requires electricity. In an emergency with loss of
power, this treatment will not work.
is not effective at removing dissolved minerals and salts.
Caution - The effectiveness of the process is
dependent, on good mixing of ozone with the water, and ozone does not
dissolve particularly well, so a well designed system that exposes all
the water to the ozone is important.
In the home, ozone is often combined with activated carbon filtration to
achieve a more complete water treatment.
Activated Alumina is a granulated form of aluminum oxide. In this
process, water containing the contaminant is passed through a cartridge or
canister of activated alumina which adsorbs the contaminant. The cartridge
of activated alumina must be replaced (or regenerated) periodically. Activated alumina
devices can accumulate bacteria, so treated water may have higher bacteria
counts than raw water.
The advantages of Activated Alumina filters include:
||An effective way to reduce levels of fluoride, arsenic, and selenium
without using distillation or reverse osmosis.
The disadvantages of Activated Alumina filters
This article concludes
that the process of activated alumina filtration as safe, but states that under certain conditions, trace amounts of aluminum, "which would normally not exceed 40-60 μg/l", might be released into the filtered water - that's more than 20 times less than the EPA Maximum Secondary Contaminant levels for aluminum.
||The use of other treatment methods would be necessary to reduce
levels of other contaminants of health concern
|'Altered' Water: No discussion about water treatment would be complete
these days without mention of what I call "altered" water - water that
has been treated in some way to allegedly modify the physical, chemical,
or 'energy' properties of water to provide some benefit to the body. These treatments fall under a wide range of categories, including:
pi mag; oxygenation; hydrogenation; various 'catalytic', vortex, magnetic, & photonic
treatments; microclustering; super-ionization; homeopathic succussions;
Note - Oxygenated water, discussed below, is just one example of the hundreds
of 'altered' or 'enhanced' water products promoted on the internet and in
some health food stores. These products all have several
characteristics in common that are discussed in more detail on the
Altered Water and
Drinking Water Scams pages. It is easier to demonstrate the flaws
in Oxygenated water claims than in other products that claim to use some
exotic physical or chemical process, but just like oxygenated water, none
of the other products are able to withstand critical scientific review.
Regardless of any alleged health benefits, these products
are extremely effective at separating customers from their money - I have seen
some of this bottled water sell for more than $20 a gallon plus shipping (that's
over 3,000 times
greater than the cost of tap water)! Many of the 'altered' water products
sell for $10 to $15 per gallon. Water 'ionizers' that generate
alkaline water produce sodium hydroxide (an effective drain cleaner) and
bleach and sell for up to $5,000.
Let's look briefly at one 'altered' water example:
hiOsilver oxygenated water
- soon to be O2Cool Oxygen Water:
Why drink hiOsilver oxygen water?
According to the marketing hype,
it provides "extra energy and vitality, fresh breath, healthier gums and teeth. We do not know all of the benefits of drinking hiOsilver Oxygen Water. Many people report that they feel energized after a bottle. Studies have been done showing enhanced sports performance for athletes drinking oxygenated water. With hiOsilver, many people report that their headaches disappear, even migraine headaches. One bottle of hiOsilver Oxygen Water and you will see why we are proud of the many benefits it offers over ordinary bottled waters . . .
hiOsilver oxygenated water water sells for $44 (for twenty four, 16 oz bottles - 3
gallons) but you do get free shipping!
If my math is correct, that's over $14.50 per gallon. By comparison, tap
water costs around $0.007 per gallon (2,000 times less than the oxygenated
water). The highest quality filtered water is
about $0.07 per gallon (that
is still over 200 times less expensive than the oxygenated water). I suppose some people might be able to justify the
exorbitant cost IF the product performed as advertised --- but does it?
super oxygenating water cooler system
marketing materials make these 'exciting' claim - and a
Some facts to consider when evaluating the oxygenated water hype:
- Extra supply of oxygen to the body for overall health improvement
- Enhancement of the brain function for clearer thinking and alertness
- More oxygen to the muscle to increase energy and performance
- More oxygen to skin cells for healthier, younger looking skin
- Enhanced metabolism and waste removal
- Enhancement of the body's ability to fight bacteria and viruses
- Better absorption of vitamins, minerals and other nutrients
(A 2011 update - the Oxygenating Cooler is
apparently no longer on the market)
There is less dissolved oxygen in 1 liter of 'oxygenated
water' than in 1 breath of air. Taking an extra breath of air when exercising would be substantially less expensive
than paying $1 to $2 for a liter of these products!
The primary way to transport oxygen in the body is bound to hemoglobin in
the red blood cells. In normal healthy exercisers,
hemoglobin leaving the lungs is already 97% to 98% saturated with oxygen.
The structure of the circulatory system ensures that any
oxygen picked up in the digestive system would o through the lungs before
reaching the muscles and other tissues. In the lungs any extra oxygen in the blood will reduce the amount of oxygen transferred to the blood - the final oxygen saturation
of the hemoglobin would still be 97% to 98%.
Oxygenating water has no effect on the body's ability to absorb the oxygen
into the bloodstream or transfer it throughout the body..
The concept of obtaining significant amounts of oxygen
through the digestive system makes as much scientific and physiological sense as quenching your thirst by inhaling a
water into your lungs. Water that you drink can take up to an
hour or more to travel to the intestines where it is absorbed - the
water you inhale into your lungs will absorb into your bloodstream
almost immediately - so doesn't it make sense to quench your thirst by inhaling a glass of water?
not try this experiment!!) This is not an endorsement
for inhaling water. The point is, the respiratory system is
designed to absorb oxygen, no water! Oxygenated water makes sense for fish
specialized structures (gills) for exchanging oxygen and carbon dioxide in
an aquatic environment, but not for mammals. Similarly, the digestive system is designed to absorb water and
nutrients, not oxygen!
Council on Exercise (ACE) Study Investigates Super Oxygenated Water Claims
- Results of a study done to test health claims. Conclusion: “At
this time, there is no scientific evidence or logical rationale to suggest
that drinking super oxygenated water can in any way increase the amount of
oxygen in the blood stream,” said Porcari. “Therefore, any potential
benefits of super oxygenated water would undoubtedly be attributed to the
A single breath of air contains more oxygen than a bottle of oxygenated water. Despite advertising claims that oxygenated water can boost sports performance,
a study in the Nov. 12, 2003, Journal of the American Medical Association found that compared with tap water, it had no effect on 9 exercise-performance measures in 11 healthy men and women.
Oxygen water: Are you being ripped off? There's very little
reliable evidence to show that oxygenated (or oxygenized) water has any
significant effect on exercise performance, energy levels, or recovery. This
water isn't going to hurt you, but there's no reason to believe it's going
to help you substantially.
from Kevin Sayers'
Another reason Oxygenated water was selected as an
example is because there are actually some well-conducted experiments
available that demonstrate that the product does not perform as
advertised. With most of the 'altered' water products, scientists
do not bother spending the time or resources to refute claims which they
perceive as completely and obviously bogus and not worth examining.
Be aware of the following when evaluating these products:
None of these products is effectively regulated by the government (over and above standard rules to ensure safety of bottled water -
discussed under the Bottled
Water section above). Companies seem completely free to make any unsubstantiated claims they wish (except
claims - which would place them under the jurisdiction of the FDA
where they would be required to scientifically prove their claims).
With that in mind, read the promotions very, very carefully. You
will find that the companies describe various health conditions in
great detail. Then they attribute the condition (sometimes accurately) to a
lack of water, or polluted water, or insufficient oxygen, etc.
However, they seldom link their specific process of treating the water directly to
solving the specific health problem they discussed - except in the most general, unverifiable
way, like 'drinking enough water is critical to your health', or 'drinking
our water will reduce stress and give you more energy'.
Any claims on the site that directly link the specific water treatment to specific health benefits are typically made by
'others' in testimonial statements. There are no regulations in
place to ensure that testimonials are either truthful or accurate or even come from real
There will be much mention in the promotional materials about scientific tests proving that a particular water treatment has
some benefit to the body, to endurance, to mental function, or whatever.
There will be, however, a complete lack of substantiated scientific
evidence to back up those claims. Acceptable evidence would be experimental
results published in journal articles that have been reviewed by other scientists to make certain the
experiments were carried out (and interpreted) correctly and with
Aqua Scams - The purpose of this site is to examine the scientific validity of the
explanations given by the proponents of "alternative" water treatment
devices or, in the case of "clustered water", of a fictional
alternative form of water that is purported to be a restorer of youth and vigor.
My motivation for doing this is entirely non-vested and very simple: after
thirty-four years of teaching general, physical, and environmental Chemistry, it
disturbs me to see my favorite science presented incorrectly (and often mangled
into pseudoscience) in the promotion of processes or devices offered to the
(Stephen K. Lower, Ph. D., site
author). Two other relevant topics Dr.
Lower discusses: Cluster
Quackery, Structure-altered water nostrums and nonsense and Oxygenated
water, pseudoscientific snake-oil.
A site from
the James Randi Educational Foundation has several interesting comments on Penta Water and the Foundation's attempts to persuade the company to
participate in their million dollar challenge. http://www.randi.org/jr/08-24-01.html,
(about 3/4 of the way down), http://www.randi.org/jr/083002.html
(about 1/2 of the way down) and http://www.randi.org/jr/121903lins.html
( just over 1/2 of the way down)
of Water-Related Frauds and Quackery
response to questions asked by one of my visitors about claims
made by companies selling "altered water" and how to evaluate
In the final analysis, I would have to say that I
have seen absolutely nothing that would lead me to believe that any of these
specialized water treatment methods can do anything at all to increase the health
benefits of water that is free of harmful contaminants.
I would be extremely interested to see some results of
good scientific experiments that demonstrated any beneficial health
effects of drinking "altered" water. My belief is that good
scientific studies on this topic simply do not exist, because the claims can not be verified.
You might ask why don't scientists carry out experiments and
publish results refuting these claims if they are not true. My best guess is
that for the scientific community these are non-issues. There are far more
interesting and important topics to spend valuable research resources and effort on than
debunking strange theories and marketing tactics that result in people
eagerly spending their money on outrageously priced water
often receive questions about Masaru Emoto's books and theories that
water is able to receive human thoughts, words, and emotions and change
the way it crystallizes - forming beautiful crystals in response to
positive thoughts, words, and emotions and ugly crystals (or no
crystals) in response to negative thoughts, words, and emotions (or
pollution). There is absolutely no scientific evidence to support
his claims. I discuss my thoughts on his popularity (among
Comparison of Drinking Water
I developed a Comparison
Table listing different drinking water treatment technologies and
the contaminants they remove to make it easier for you to determine
which process, or combination of processes will be best for your
particular drinking water situation.
this table is too large for your screen, I have
broken it into two separate tables, one
covering the biological
and the other covering the
They should be
easier to read on monitors set at 800 X 600.
I also developed another
table that shows similar water treatment information in a somewhat
different format that you might want to take a look at. This
table is geared mostly to point of use water treatment methods.
Quality Association (WQA) also has a Table
of Water Contaminants, their health effects, and removal methods
The pore size of a filter determines
how well it removes harmful particulate contaminants like asbestos, parasitic cysts, and
Solid Block, Activated Carbon filters have very small carbon
particles bonded into a tightly packed matrix with uniform pores, typically
between 0.5 and 1.0 micron, and can reliably remove small particulate
Granular Activated Charcoal (GAC) filters have relatively large,
and irregular sized pores (10 microns would probably be the minimum size to
expect), so it is impossible to state with
any certainty what size particles would be removed. Channeling can also
dump unfiltered water into the output stream.
only filters should never be relied on exclusively to provide protection from
small particulate contaminants.
a full sized figure that compares the relative size of several biological contaminants
with the pore size
of some common filters.
of Long-Term Costs for Water
||Have you considered how much it will cost to obtain
pure, safe water for the next 5, 10, 20, or even 40 years?
||When you decide to protect yourself and your family
from drinking water contaminants, 40 years may seem like a very long
time to think about treatment costs.....
||If you plan to use just 10 gallons of purified
water a week (less than 1.5 gallons per day), the water treatment method you select can mean the
difference between spending about $1,500 over 40 years or spending more
than $31,000 for pure, safe water!
||Click below on the amount of purified water you use
(or would like to use) per week. This will display a table and graph
comparing the average costs of some common treatment methods (bottled
water, distillation, reverse osmosis, SBAC filtration, and pitcher
cost tables (as well as the filter performance tables) convinced me to consider seriously a top-of-the line, Solid
Block, Activated Carbon (SBAC) filtration system. Although the
initial cost was higher than many cheaper alternatives, the cost over several years was much
lower than other options - at most usage levels. The fact that SBAC
filtration was simpler to use than other methods and significantly
contaminants I was liable to experience in my municipal water, sold me
on the technology. I have provided some information
on how to request information about
my recommendation for a top-of-the-line SBAC filtration system.
advised that the information on this page and on this site is for
general educational information only and is NOT intended to make any
specific health claims or recommend any specific treatment method or
preventative advice for any health issue or problem. Consult your
physician or a health specialist for specific steps to take for your
specific health requirements!
|Copyright © 2005 Randy Johnson. All rights reserved.
Updated November 2011