It is important
to understand the difference between Solid Block Activated Carbon (SBAC)
Filtration and Reverse Osmosis or Distillation. Occasionally
people
are disappointed with their water quality after installing a
high-end SBAC filtration system and
discovering that their filtered water still has an
undesirable taste or odor.
· If
your untreated water has no unpleasant smells or tastes
besides chlorine, an activated carbon filter will most
likely
provide excellent tasting and smelling water. However, if
your untreated tap water has a metallic, bitter or salty taste,
activated carbon filtration will probably NOT be sufficient.
Other smells &/or tastes may or may not be reduced by activated
carbon – it depends on what the specific contaminants are.
· Taste
and odor problems do not necessarily have anything to do
with the safety of your drinking water – many harmful
contaminants have no taste or odor and many that cause
unpleasant tastes and odors are not particularly harmful.
However, contaminants that cause taste and odor problems
will make your water less pleasant to drink, and if you
invest in a water treatment system, you expect to be able to
drink water without disagreeable tastes or odors. So, it is
important to understand the strengths and limitations of
activated carbon filtration.
· Activated
carbon filters excel at reducing taste and odor problems
caused by chlorine (the better models also reduce chloramines),
and a wide variety of organic chemicals. Taste and odor
problems in municipal water from most cities in the U.S. and
Canada can be effectively treated by a high quality
SBAC filtration system because high levels of
salts &/or metal ions are not usually a problem.
· If,
however, the taste or odor of your water is caused by salts
(chloride or nitrates) or metal ions like iron, manganese, selenium, barium,
cadmium, copper, etc. there are no activated carbon filters
(SBAC or granular) that will effectively remove those contaminants and
eliminate those tastes/odors. In these situations
there are several options:
o
If you have really poor
tasting/smelling drinking water from a municipal water
provider, it is important to understand what is causing
the problems so you can order the most effective treatment
option and not be disappointed by a system that fails to
correct the problem. To discover what contaminants are
in your municipal water that cause the taste/odor problems
you experience, you can read the annual water quality report
from your water company or call your water provider and ask.
Some information about taste and odor problems can be found
here.
o
If you discover that the
contaminants that cause your taste/odor problems can't be
removed by a high quality activated carbon filtration
system, and they only affect your drinking water, the
most effective treatment options would be a Point of Use
distillation or reverse osmosis system. A few
municipal drinking water facilities may meet EPA
requirements for safety, but still allow enough salts and
metal ions to cause taste and odor problems.
o
If you have done some research and
are still not sure whether a high-end SBAC filtration system by itself will significantly reduce the
contaminants causing your taste and odor problems, you can
experiment with a cheap activated carbon pitcher filter.
While I do not recommend them as long term treatment solutions because
of their relative ineffectiveness, low treatment volumes and
high long-term expenses for replacement cartridges, they
might provide some useful information.
- Fill the pitcher
filter with your tap water and allow it to
go through the filter.
- After the water has
been filtered, pour it back into the top of
the pitcher and let it percolate through the
filter again (to increase effectiveness)
- you could even run the water through the
filter a third time. The activated
carbon in the pitcher filter will reduce a
similar group of contaminants as a high-end
SBAC filter cartridge and also will not
reduce the salts or metal ions. So,
any remaining contaminants in the
pitcher-filtered water that cause taste and
odor problems should be similar to those
remaining in the high-end SBAC filtered
water.
- In order that your
expectations do not get in the way of your
observations we will blind the test. This is
also a good method to determine which wine
or beer brand really tastes better
and it can solve important family disputes
like, "does day-old coffee taste worse than
freshly made coffee?"
- For the blinded
water comparison you will need to find a
friend or family member who will assist
in the experiment but not participate in
the sampling.
- The assistant
will draw as many glasses or cups of
unfiltered water and filtered water as
there will be people sampling the water
while those participating in the
experiment are out of the room - and
not watching.
- The assistant
will set the water glasses on a table or
counter, one filtered and one unfiltered
glass of water for each person participating
in the experiment. The assistant
will record (or diagram) which of the
glasses contains filtered water and
which contains unfiltered water.
It does not matter whether the order of
filtered/unfiltered water is the same or
different for each experiment
participant, only that the assistant has
a good record. The record of which
glass is which will not be shared with
the experiment participants until step
7.
- The glasses will
need to stand until all water reaches
about the same temperature.
- The assistant
will withdraw from the room, remove all
documentation about the contents of the
glasses, and notify the experiment
participants that they can go in and
sample the water. The assistant
will provide no hints about the
placement of the water, and it is best
that the assistant remain out of the
room to avoid compromising the
experiment by tossing out inadvertent
comments.
- The participants
will enter the 'experimental chamber'
with note paper and pens, take their
stations in front of the water glasses,
carefully sample the water in each glass
without commenting to other
participants, take notes about the
taste and odor of each sample, and not
change the arrangement of their glasses.
- Once everyone has
sampled water to their satisfaction and
recorded their observations, the
assistant will re-enter the room and
unblind (identify) the contents of each
glass.
- It should be
fairly obvious whether the activated
carbon has made a significant,
noticeable difference in the taste and
odor of your tap water, and you can use
the results to determine whether a
high-end SBAC filtration system will be
an optimal solution for you or whether
reverse osmosis or distillation would be the better
option.
- Good luck!
o
If your taste/odor problems affect all
home-use water (drinking, bathing, washing, etc.) a whole
house treatment solution might be required. Normally these
extreme methods are only needed for private well water, not
municipal water.
o
As I have
mentioned elsewhere, private well, spring or surface water
sources can have a wide range of potential contaminants and
may require extensive testing, specialized whole house
treatment methods, and constant monitoring.
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