Table of Contents

                                Home water treatment facts	   pg.2

                                Advice for people with severely compromised
                                immune systems (Sidebar)	  pg.2

                                Local water quality	  pg.3

                                Cost and maintenance	  pg.4

                                At-home solutions to water
                                quality problems (Sidebar)	  pg.4

                                Performance	  pg.4

                                Point of use devices	  pg.5

                                Point of entry devices	   pg.6

                                How filters work (Sidebar)	   pg.6

                                Certification	  pg.7

                                Contact information ...
                                EPA registration of
                                water filters (Sidebar)

Advice for  people  with
severely    compromised
immune systems

Some people may wish to take
special precautions with the water
they drink In  particular; people
with immune systems that are
weakened by AIDS, chemothera-
py or transplant medications are
more vulnerable to microbial con-
taminants in  drinking water such
as Cryptosporidium.

Cryptosporidium is a microscopic
parasite that lives in the intestine of
infected  animals and humans. It
passes in the stool in its dormant
oocyst form.The oocyst is protect-
ed by an outer shell that allows it
to survive outside the body  for
long periods of time and makes it
very resistant to  chlorine-based
disinfectants.  It occurs  mainly in
surface  water  sources,  such  as
lakes, streams and rivers. In healthy
adults, Cryptosporidium can cause ill-
ness, but for people with weakened
immune  systems,  it can  cause
severe illness and even death.

Those who  wish to take extra
measures to avoid  waterbome
cryptosporidiosis can bring their
drinking water to a boil for a  full
minute.  Boiling  water  is the
most effective way of faffing
Cryptasporidium.As an alterna-
tive to boiling water, people may
take the following measures:

Use a pointrof-use filter

Consider using point-of-use (per-
Home Water Treatment Facts

Americans spend billions of dollars each year on home
water treatment units.According to the Water Quality
Association, more than four out of 10 Americans use a
home water treatment unit These units range from
simple pitchers costing less than $20 to sophisticated
reverse osmosis units costing hundreds of dollars.

Some people use a home water treatment unit to
improve the taste of their tap water. Others treat their
water because of health concerns. While EPA does not
endorse specific units, the Agency does set and
enforce national standards for the tap water provided
by public water systems.

Drinking water can reasonably be expected to contain
at least small amounts of some contaminants. As long
as those contaminants are at levels no higher than
EPA standards, the water is considered safe to drink
for healthy people.  People with severely weakened
immune systems or other specific health conditions, or
those concerned about specific contaminants present
in local drinking water, may wish to further treat their
water at home or purchase high quality bottfed water.

Before purchasing a home water treatment unit, con-
sider local water quality, cost and maintenance of the
unit, product performance, and certifications to make
sure that the unit will meet your needs.

Local water quality	

Begin by learning as much as possible about your tap
water. If you haven't already received it, contact your
local water supplier and ask for the annual water
quality report (sometimes called a consumer confi-
dence report). This  report lists the levels of contami-
nants that have been detected in the water and
sonal use, end-of-tap, under sink)
filters that remove  particles  one
micrometer or  less in diameter
Filters that use  reverse osmosis,
those labeled as "absolute  one
micron filters," or those labeled as
certified  by an American National
Standards  Institute  (ANSI)  -
accredited    organization    to
ANSI/NSF Standard 53 for "Cyst
Removal" provide  the greatest
assurance    of      removing
Cryptosporidium. As with all filters,
follow the manufacturers  instruc-
tions for filter use  and replace-

Use bottled water

Check the label or call the bottler
to find out how bottled water is
treated.  The  following bottled
water treatments protect against
Cryptosporidium: reverse osmosis,
distillation, ultraviolet light, or filtra-
tion with an absolute one micron
filter. Bottled waters derived from
protected well and  spring water
sources  are less  likely to be con-
taminated by Cryptosporidium than
those containing untreated munic-
ipal drinking water from less pro-
tected sources such as rivers and

Those who choose  to take these
precautions  should  remember
that they can  be  exposed  to
waterbome  pathogens  through
water used for brushing teeth,
making  ice  cubes,  and washing
fruits and vegetables  - not  just
through  water they drink
shows how these levels compare with EPA's drinking
water standards.

Some contaminant levels remain constant throughout
the year, while others vary according to season,
weather, or from house to house.  For example, lead
typically occurs when it leaches from the lead pipes
and solder that are in some homes. If you  are con-
cerned  about a contaminant whose level may vary,
consider getting your water tested (use a certified labo-
ratory for the most reliable results). Use this informa-
tion to help decide on  a home water treatment unit

If your water comes from a household well, EPA
recommends annual water testing for nitrates and co\-
iform bacteria. In addition, check with your heo/th depart-
ment or local water systems that use ground water for
information on contaminants of concern in your area.

Armed wifh this specific information, you can deter-
mine your purpose in  buying a home water treatment
unit to remove specific contaminants; to take extra
precautions because a household member has a
compromised immune system; to improve the taste of
the water, or some combination of these concerns.

At-home   solutions   to
water quality problems

Improve taste

If you object to the chlorine
taste  of your tap water, try
placing   the  water   in  an
uncovered  pitcher  in   the
refrigerator  overnight.  This
will reduce the chlorine taste.
Most  tap  water  is  treated
with chlorine to kill disease-
causing  microbes. Water sys-
tems  use chlorine because it
is an effective disinfectant for
viruses   and  bacteria,  and
because it continues to disin-
fect  water   as  it  travels
through pipes.

Reduce lead

If you have tested your water
and know that it has high lev-
els  of lead, or if your home
has lead pipes, flush the  cold
water tap by  running it until it
becomes  cold  if  the water
hasn't been used for several
hours. Lead accumulates  after
extended contact with  lead
pipes.  You  may  use  this
flushed water to water plants
and   do  other  household
Cost  and Maintenance	

Prices vary depending on type (pitcher, faucet filter,
etc.), where and how the unit is installed, and what
contaminants it removes. Prices can range from $20
for a simple pitcher to hundreds of dollars for a
reverse osmosis unit

All units require some maintenance, and it is impor-
tant to follow #7e manufacturer's recommendations
for replacements. For example, activated carbon filters
are designed to filter a certain amount of water; after
that, the filers become clogged and ineffective. Check
the schedule and cost for replacement filers.


The following information briefly describes how differ-
ent types of home water treatment units work For
details, read information that accompanies
the product and look for independent
certification of manufacturers' claims.

Different units remove different contaminants or classes
of contaminants from the water. Sophisticated units
may use multiple technologies to remove several types
of contaminants and to provide backup protection in
case one treatment fails.

A water treatment device can  either be free-standing
attached to a tap, plumbed in with a dedicated faucet
(also called  a point-of-use device) connected to a
refrigerator's water and ice dispensing system; or cen-
trally attached to treat all water entering a house (a
point-of-entry device).

For most contaminants, a point-of-use device is effec-
tive for treating only Jfte  water that is consumed.
However, some contaminants, such as radon, disinfection
byproducts,  and some organic chemicals, easily turn
At-home   solutions   to
water quality problems

Kill microbes

If you have  a contaminated
private  well,  have  special
health needs (see  left side of
page  2),  or in an  emergency
situation such as a flood, boil
water for one minute to kill
microbes (or three minutes
at altitudes greater than one
mile)  and  place  in  a clean,
covered  container.
into gases and may pose a risk when inhaled, such
as when showering. A point-of-entry device can
reduce concentrations of these contaminants and
others that cause aesthetic problems such as scal-
ing, staining, or odor.

Point-of-Use  Devices:	

Filter pitchers: Water filtration pitchers are an
affordable and commonly used free-standing home
water treatment device. Most water pitchers use gran-
ular-activated carbon and resins to bond with and
trap contaminants.These filters are effective at
improving the  taste of water, and many will also
reduce lead and other contaminants.

Specific contaminants removed vary by model and
depend on Jfte pore size and other factors. An acti-
vated carbon filter, by itself, is not designed to remove
all disease-causing organisms. Carbon filers have a
specified shelf life and should be replaced regularly
according to the manufacturer's instructions.

How filters work

A water filter is composed of
a screen with  many micro-
scopic holes. The smaller the
holes, the more contaminants
the filter can  remove.  Filter
holes   are   measured   in
microns. (The period at the
end  of this sentence is 500
microns.) When considering
filter  size,   look   for  an
absolute  (the largest  hole),
not  a nominal  (the average
hole),  rating.  EPA and  CDC
recommend an  absolute one
micron filter  (or one labeled
for cyst removal) to remove

Some contaminants and their
size in microns:

Giardia lamblia - 8 to  12

Cryptosporidium parvum -
4 to 6 microns

Bacteria (such  as E. coli and
salmonella) - 0.2 to 4 microns

Viruses   -   0.004   to  O.I
microns  (Generally,  only  a
few filters, such as ultrafilters
and  reverse  osmosis,  have
holes small enough  to assure
removal   of   all   viruses.
However,  viruses   can  be
killed using a disinfectant).
Filters that attach to a faucet or are installed
under the sink for a drinking water third faucet
These fifeers generally use the same technologies as their
pour-through pitcher counterparts. Some filters use fabrics,
fiber, or ceramic screening to physically remove contami-
nants. The most common types use a molded block of
activated carbonJhese filers are effective at improving the
taste of tap water, and some wil also reduce lead, proto-
zoan cysts, and many other contaminants. Like filter pitchers,
shelf lives and specific contaminants removed vary so read
the label and instructions carefully.

Distillers: Distillers heat water to the boiling point,
and then collect the water vapor as it condenses, killing
disease-causing microbes and leaving most chemical
contaminants behind. Contaminants that easily turn
into gases, such as gasoline components or radon, may
remain in the water unless the system is specifically
designed to remove them. Distilled water may taste flat
to some people because the water's natural minerals
and dissolved oxygen often have been removed.

Reverse Osmosis Units: Reverse osmosis unte force
water through a semtpermeable membrane under pres-
sure, leaving contaminants behind. Reverse osmosis
units use approximately three tones as much water as
they treat, but they are effective in eliminating all disease-
causing organisms and most chemical contaminants.

Pofnt-of-Entry Devices:	

Adsorptive media:  Liquids, so/ids, dissolved or
suspended matter adhere to the surface of, or in the pores
of, a solid material. Carbon filers use this technology.

Aerators: Aerators force water to travel over air jets.
Contaminants that eas^ turn into gases, such as gasoline
components and radon, are removed. Other contamnants
are notThe water may be additionally filtered after it passes
through this system to remove additional contaminants.
Removing specific con-

Giardia and Cryptosporidium
- distillation, reverse osmosis,
absolute  one  micron  filters,
ultraviolet  light,  and  filters
certified for cyst removal.

Bacteria and viruses - distil-
lation, reverse  osmosis, ultra-
violet light, and disinfection.

Arsenic - adsorptive media

Disinfection  byproducts  -
point-of-entry adsorptive media
systems distillation, aeration,
carbon filtration and  reverse

Lead  -  distillation,  reverse
osmosis and some carbon

Nitrates - distillation, reverse
osmosis or ion exchange.

Pesticides - some carbon

Radium  - ion  exchange, dis-
tillation or reverse osmosis.

Radon -  activated carbon
filter and aeration.
Water Softeners: Water softeners use a cation
exchange resin, regenerated wtth sodium chloride or
potassium chloride, to reduce the amount of hardness
(calcium, magnesium) in the water.Trie hardness ions in
the water are replaced wifft sodium or potassium ions.
Ion exchange water softeners simultaneously remove
radium and barium while removing water hardness.


Make sure that the unit you intend to purchase can
address your concerns.There are three different certifi-
cations to look for on the labeLThese organizations
can also assist you in selecting a device that meets your
needs. If a home water treatment unit isn't certified by
one of these organizations, contact the manufacturer
directly and ask for proof of the manufacturer's claims.

Three organizations are accredited by the American
National standards Institute (ANSI), and they each certify
units using ANSI/NSF standards. EachANSI/NSF stan-
dard requires verification of contaminant reduction per-
formance claims, an evaluation of the unit, including its
materials and structural integrity, and a review of the
product labels and sales literature. Each certifies that home
water treatment units perform to meet or exceed
ANSI/NSF and EPA dmkhg water standa/ds. ANSI/NSF
standards are issued in two different sets, one for health
concerns (such as removal of specie contamhants) and
one for aesthetic concerns (such as improving taste or
appearance of water). Certification from these organizations
wif be tied to one or both of these specific standards.

NSF International: The NSFWater treatment Device
Certification Program requires extensive product testing
and unannounced audits of production faclitiesThe goal
of this program is to provide assurance to consumers that
the water treatment devices they are purcriashg meet the
design, materiai and performance requirements of national

EPA registration of water

Some units have an EPA regis-
tration number and an EPA
establishment  number.  EPA
registration (unlike  that  of
NSF, WQA, or  UL)  is not
intended to guide consumers
in  selecting a  water  treat-
ment device, and  is not  an
endorsement of the product.
EPA registers  any product
that contains an antimicrobial
(germ-killing) or bacteriostatic
(slowing  or inhibiting growth
of germs) agent. EPA registers
these products because con-
sumers cannot independently
verify  whether the  germ-
related claims  they make are

For most units, an EPA regis-
tration  number means that
the filter uses a bacteriostatic
agent to slow the growth of
microbes within the filter, the
unit does not pose a human
health  threat, and  EPA  has
verified  all   bacteriostatic
claims   on    the    label.
Registration   is    not   an
endorsement of the filter  or
its  performance.  The  most
commonly used bacteriostatic
agent is silver.
Underwriters Laboratories: Underwriters
Laboratories, Inc., is an independent, accredited testing
and certification organization that certifies home
water treatment units which meet or exceed EPA and
ANSI/NSF drinking water standards of contaminant
reduction, aesthetic concerns, structural integrity, and
materials safety.

Water Quality Association: The Water Quality
Association is a trade organization that tests water
treatment equipment, and awards its Gold Seal to
systems that meet or exceed ANSI/NSF standards for
contaminant reduction performance, structural integrity,
and materials safety.

For more information about water
treatment units:
NSF International
P.O. Box  130140
Ann Arbor, Ml 48113-0140
877-8-NSF-HELP; (877) 867-3435

Underwriter's Laboratories, Inc.
333 Pfmgsten Road
Northbrook, IN 60062-2096
(877) 854-3577
mail to: water@us.u/.com

Water Quality Association
4151 Naperville Road
Lisle, IL 60632-3696
EPA also registers a type of
water   treatment   device
known as a purifier.A purifier
must remove, kill, or inacti-
vate all types of disease-caus-
ing organisms from the water,
including viruses. Few water
treatment devices can meet
these  criteria. These units
typically work using a disin-
fectant within the filter to kill
or inactivate microbes. Most
purifiers are used by hikers
or campers  and  are not gen-
erally  needed   in   homes
served by public water sys-
tems unless  there is a water

EPA's  Office of  Pesticide
Programs'     Antimicrobial
Division  website  provides
additional   information  on
EPA product registrations,
www.epa.govloppadOO I.
You  may  also  contact  the
Antimicrobial Hotline at 703-
308-0127  (phone); 703-308-
6467   (fax);   or   e-mail
For more information about tap water:

EPA's Safe DrinkingWater Hotline
I (800) 426-4791

www.epa.gov/sofewater - includes drinking water
standards, state certification officers for water testing
and information for household well owners.

September 2005