Subject: home water purification systems: a guide to making the right choice, part 1

From: [email-masked] (Ian Hewitt)
Date: Mon, 30 Jan 1995 21:26:44 -0800

We thought this information, a two part guide, would be of great use for
those of you interested in purchasing a water filter, or for those simply
considering whether they need one or not.  If you have any further
questions about home water purification systems, and about how to obtain
the one that best suits you, please call Dr. Denise Downey at the Pure
Water Network (800) 869-6691, or send your e-mail to
[email-masked].  We will respond to you promptly.

   HOW TO CHOOSE A WATER FILTER

   or

WE KNOW THE WATER IS BAD -- NOW WHAT DO WE DO?

You're spending a small fortune on bottled water and you know it's just a
temporary solution.  But where do you start when it comes to water
filtration? Get the latest, up-to-date info to help guide you through the
maze of choices.  Learn what to look for, what to avoid, the hidden costs.
   There is an enormous boom today in the awareness and usage of
alternatives to drinking tap water.  There are hundreds of new bottled
waters now on the market and just as many hundreds of choices of various
filtration devices.
   Consumer protection is just starting to be put into action in the last
two years.  In this guide, we'll bring you up-to-date on what to look for,
what the ratings mean, and how to completely protect your drinking water
sources.  Included in this guide are:

I. Brief history and update on the water problems we face today
      --what the municipalities can deliver
      --what the state and federal governments can regulate and enforce
II.   Drinking water problems and their sources
      --why point-of-use systems are the most logical and efficient
      --why it is the individual's responsibility to guarantee their own
drinking water         purity
      --why over 20 million households will have one by year 2000
III.  The main technologies available to the consumer 
      --pros and cons of each technology
         --granular activated carbon
         --solid carbon block
         --distillation/reverse osmosis
         --KDF resin
         --ultraviolet/ozonation
         --bottled water
IV.   Consumer protection when purchasing a water filtration device
      --What is NSF?
      --Why is NSF the industry standard nationwide as of 1992?
      --How does NSF compare to Consumer Reports?
V. The hidden costs of water filtration

If all the earth's water, fresh and salt, were to fit in a gallon jug, the
available fresh water would only equal a little over a tablespoon.  Only a
small part of that tablespoon would be water to drink!  In your home, only
one half of 1 percent of your household water usage is for drinking water
-- yet on this small amount rests all your health functions.

Drinking Water Regulations

   In 1972, the Federal Clean Water Act targeted what is known as "point
source pollution" - contamination coming from specific industries and
industrial sites.  The act helped start massive cleanups of rivers, lakes
and streams brought to the point of biological death in many cases.
   The action resulting from this legislation helped resolve point source
pollution problems but non-point source pollution remains rampant
nationwide.  This type of pollution comes from rain drains, leaking septic
tanks, leaking gasoline storage tanks and agricultural ground water
pollution.
   The federal government mandates to the states, with EPA participation,
to set minimum acceptable contaminant levels in drinking water supplied
through the local municipal systems within each state.
   Municipal systems are regulated by state guidelines and monitored by
local districts.  They are allowed to deliver water with certain minimum
levels of sediment, organic matter and non-pathenogenic (non-disease
producing) bacteria.
   Often, they violate these standards, especially during periods of heavy
rain.  However, they don't stop delivery (except in the most extreme
cases) - they are only required to notify water users in the interim. 
Eventually they are required to fix the problem but sometimes, for example
with asbestos, the problem is impossible to fix due to economics and/or
logistics.
   If people are actually getting sick, i.e. with diarrhea or worse, then
more drastic measures are taken.  For the most part, the action taken
consists of notifying people that they need to boil their water or buy
bottled water until otherwise notified.
   In essence, the government can't solve the situation overnight.  The
problems are too massive and too complex.  For example, out of over
300,000 toxic waste sites, the EPA has targeted one thousand of them as
priority. Five years and $1.5 billion dollars later, few sites are cleaned
up and the resulting damage to the groundwater supplies will remain for
decades, even centuries.
   Local governments, municipalities and water companies do their best but
they are severely handicapped by a lack of funds, by the inability to test
for a wide range of contaminants and by antiquated distribution systems,
such as pipelines constructed of lead or asbestos.  One example is
compliance with the EPA priority list of 129 toxic chemicals found
nationwide in the drinking water -- most municipalities test for less than
thirty of these!

Drinking Water Problems

Chlorine:
   The experimental use of chlorine began in the 1890's to combat
water-borne diseases such as cholera and typhoid.  It quickly gained wide
acceptance because of low cost and high efficiency in killing just about
everything hazardous in the water.  Chlorine allowed population centers to
spring up and thrive without any epidemic outbreaks.
   The problem with chlorine is that it is a known poison and the safety
of drinking this poison over the longterm (i.e. your lifetime) is highly
uncertain.  Also, chlorine reacts with water-borne decaying organic matter
like leaves, bark, sediment, etc. to create a family of chemicals called
trihalomethanes and other highly toxic substances.  Trihalomethanes, or
THM's, include chemicals such as formaldehyde and formalin, both of which
are extremely carcinogenic even in minute amounts.

Chloramine:

   Chloramine is another substance used now in many larger municipalities
(i.e. Los Angeles).  In systems where the level of chlorine is at the
highest acceptable level but need still more disinfection, the utility
will then add a chlorine/ammonia compound.  Chloramine is represented as
totally safe but with the disclaimer to not give chloramine-treated water
to your animals or use it in your fish tanks (it kills fish)!

Bacteria:
   If you are on a municipal system with chlorination or chloramine,
theoretically you are protected against bacteria.  However, if the level
of chlorination isn't high enough from the municipal source to your tap,
bacteria can re-infect the water anywhere along the distribution system. 
The piping system -- whether it's the mains or your house plumbing -- has
bacterial growth in it happening all the time.
   If you are on a spring or a wall, with no chlorine, then you are very
vulnerable to bacterial contamination.  Even the most pure sources cannot
prevent occasional contamination from animals either dying or defecating
in the source, or from neighboring pollution (i.e. septic tanks) traveling
>from  an adjoining watershed to contaminate the source.  Also, the pipes
are again a source of bacteria.
   Many people do periodic testing on their well or spring source and rely
on this method to assure themselves that they have good water.  What they
don't realize is that there are a few problems with testing.
    First, the test is only good for the moment the sample was taken. 
Bacteria can have "blooms,² if the conditions are right, which potentially
occur hours, days or weeks after the testing and therefore remain
undetected.  Other casual contamination can occur from animal or human
sources, as mentioned above, which the test never detected because the
sample was taken before the contamination occurred.
   Second, testing can be very expensive to do, depending on what is being
tested for.  Most basic tests cover bacteria (i.e. E. coli), levels of
sediment and decaying organic matter, and amount of total dissolved solids
(mineral levels such as calcium, magnesium, iron, sulfur, 
etc.).  With any extra testing the price goes up per test.  Lead, asbestos
and specific chemical contaminants are more difficult and therefore much
more expensive to test for.

Lead:

   Lead is a cumulative toxin that stays in the tissue permanently,
especially in brain tissue.  It also affects a person in relation to their
body weight.  Therefore, an exposed adult can fend off the toxic effects
for some time but in children, brain and developmental damage occur
quickly and permanently.
   Lead pipes and lead solder in the distribution system are the main
sources of lead pollution.  Boston Globe estimates that 98% of all
households have lead in their plumbing.  Houses older than 20 years and
less than five years are most at risk.  Also, houses in areas of soft (low
mineral levels) water tend to corrode the lead from the pipes more easily.

Asbestos:

   Asbestos is another potential carcinogen that can come either from
water with naturally occurring asbestos (such as in areas that have a lot
of serpentine rock) or from asbestos-lined water pipes.  Thousands of
miles of these pipes were laid throughout the U.S. in the 1950's and have
yet to be replaced.
   Asbestos is so small that it is unfeasible to remove it at the water
treatment plant.  To build such a removal facility is prohibitively
expensive and would clog up the plant within five years of being in
operation.

Chemical Pollution:

   Chemicals are, for the most part, odorless, colorless and tasteless,
therefore undetectable.  Chlorine is the most predominant chemical in our
water.  Some of the most dangerous chemicals are present only in trace
amounts (parts per billion) but highly toxic even at these minute levels. 
Sources are usually industrial or commercial, like leaking underground
storage tanks for gasoline or industrial solvents such as TCE
(trichloroethane).  These leaking toxins end up in the groundwater or in
the municipal supply through breaks or cracks in the main water pipes.
   The biggest family of these toxics are VOC's or volatile organic
contaminants, including various plastics, gasolines and petroleum
products.
   Next is the herbicidal group such as dioxin (2-4D) and lindane, used as
a defoliant in modern logging operation and found in many wild and rural
areas.
   Along with the herbicides comes the pesticidal group such as DDT,
malathione and other toxics used in insect eradication and control.
   Also, the THM's mentioned before are a big pollutant because of the
amount of chlorination used nationwide.  They are a separate class of
chemical from chlorine itself.

Cysts:

   This last group includes microscopic worms, parasites and protozoa. 
The biggest offenders are giardia and cryptosporidia which cause major
diarrhea, dehydration, intestinal disorders and even death in people with
compromised immune systems.  Water experts estimate that over 63% of water
problems in the Unites States today are directly caused by giardia and
cryptosporidia. 
   Giardia is seven to fourteen microns in size and cryptosporidium is
>from  three to 5 microns in size.  When the environment becomes
inhospitable (like the presence of chlorine or the absence of water), both
parasites can go into the cystic form (like a hard, round impermeable
microscopic egg).  The cyst form is chlorine resistant and very hard to
kill. 
   Municipal utilities are unable to completely remove these cysts. Cysts
have been found in most major municipal water systems in the U.S. 
Milwaukee, Wisconsin had a huge outbreak of cryptosporidia in 1993 that
killed over 100 people.  San Francisco, California has repeatedly tested
positive for giardia in its chlorinated water that traveled hundreds of
miles from the Sierras.
   The human body is over 70% water.  To think that contaminants in our
drinking water have little or no bearing on our short term and long term
health picture is to ignore reality.
   Federal, state and local authorities will strive to do their best to
insure that we get the best water possible but they can't undo all of the
damage to our water sources over decades of ignorance and abuse.
   It's up to us to take personal responsibility to safeguard the water we
use to drink and prepare our food.  That responsibility starts at each
household's kitchen tap.
   Removing all contaminants at the kitchen or bathroom taps just before
consuming the water is the most logical, efficient and economical solution
to drinking water purification.  In this manner, only the drinking water
is filtered (rather than all the household water).  Also, there is no
possibility for re-contamination (i.e. in a holding tank) after purifying
the water.

Technologies Available

   There are only four to five generic forms of water purification
technologies available.

Granulated activated carbon

   Carbon is a substance that has a long history of being used to absorb
impurities and is the most powerful absorbent known to man.  One pound of
carbon contains a surface area of 125 acres and can absorb thousands of
different chemicals.  For centuries, sailing vessels used it to store
drinking water for long voyages.  Carbon is also commonly used as an
effective antidote for swallowed poisons.
   Activated carbon is carbon which has a slight electro-positive charge
added to it, making it even more attractive to chemicals and impurities. 
Loose granular activated carbon (GAC) is used extensively in most of the
commonly encountered water filters today.  Most of these filters have
ratings as simple taste and odor filters or as pre-filters designed to
remove initial dirt, rocks, sediment, etc.
   Very few of these GAC filters are effective at true purification (i.e.
removal of substances of health concern).  Below are some problems:
   
   --Channeling:  When water is forced through a substrate of GAC (which
has the consistency of sand or coffee grounds)  it takes the path of least
resistance and makes its own channels through the GAC in the filter.  What
this means is that the water being filtered is not contacting the GAC for
enough time to allow complete absorption of impurities to take place. 
Many impurities seep through along with the "purified" water.
   
   --Bacterial growth:  When the water passes through the GAC, some
bacteria are trapped in the substrate, too.  The problem is that these
trapped bacteria multiply prolifically in the warm, moist
oxygen-containing environment among the grains of GAC.  Because the GAC is
loose, there is no barrier to keep any bacteria growing inside the filter
>from  coming out with the water pushed through each time the filter is
used.  There have been extensive tests showing certain filters have
thousands more bacteria coming out of them than initially went into them! 
Some companies add silver nitrate, a known poison, to the GAC to aid in
keeping the bacterial growth down, but this method has limited
effectiveness.  There are also serious questions about adverse health
effects from the silver nitrate itself!

   --Effectiveness decreases rapidly:  Because the amount of GAC is
usually minimal in most GAC filters, they quickly become saturated and
overwhelmed with normal household usage.  The filters must be changed
quite often, which also adds to the expense of filter maintenance.

Distillation:

   Distillation is an expensive process that heats the water to the vapor
point and aids in removing some impurities from the water.  The theory is
that chemical pollution and other contaminants will be vaporized and
separated off from the vaporized water.  The treated water then passes
into a holding tank and the drinking water is drawn from this tank as
needed.  The process itself requires electricity and adequate water, since
it wastes gallons of water for every gallon produced.
   Distillation is used in rare situations where large amounts of trace
minerals (i.e. calcium, magnesium, etc.) must be removed from the water to
improve the taste.  Some people periodically drink mineral-free water for
specific health regimens such as the dissolving of kidney or gall stones.
   However, mineral-free (soft) water is detrimental to the health of the
bones, teeth and tissues if drunk over a long period.  Such soft water is
termed "aggressive" water by the EPA because of its ability to leach out
the minerals, metals or other materials of whatever it touches or passes
over.
   Other problems with distillation are:

   --Maintenance:  the units require periodic and extensive maintenance to
the piping that usually can only be done by the factory.

   --Holding tank:  all distillers require a holding tank to store the
processed water, inviting possible recontamination and bacterial growth in
the tank
   
   --Incomplete purification:  distillation is not effective at removing
the VOC's because many of them re-condense back into liquid just like the
water does.  For this reason, the distiller is usually combined with a
granular carbon filter to remove additional chemicals that slip through.

   --Environmental contamination:  in some cases, distillers have been
shown to blow vaporized contaminants out into the surrounding air of the
household.

   --Inconvenience:  with most distillers, the homeowner has to wait eight
hours to get a couple of gallons of drinking water

Reverse Osmosis

   Reverse osmosis, or RO, is another separation process that makes use of
a semi-permeable membrane.  This membrane lets particles of a certain size
or smaller through and keeps back larger particles.
   Like distillation, some contaminants can make it through the membrane
just like water molecules, so a GAC filter is added at the end of the
process to capture these materials.  RO systems also waste three to 10
gallons of water for every gallon produced.

(please see part 2)