I
CITIZENS GUIDE
TO
HOME TREATMENT WATER UNITS
USE PA REGION 4
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A CITIZENS GUIDE TO
HOME TREATMENT WATER UNITS
Many people feel the water coming out of their faucet at home is not
safe. This has caused a large increase in the amount of home water
treatment units being purchased in this country. There are many different
types of units on the market with a large variety of prices. Citizens
have become confused on whether they should purchase one at all. The
Environmental Protection Agency neither approves nor recommends any home
treatment unit for general usage. However, EPA does have jurisdiction
for three general categories of home treatment units. They are as follows:
1. Water filters are generally comprised of activated carbon, make no
claims for pesticidal (antimicrobial) activity, and are intended to
remove rust, sediment, color, odor, chlorine, taste, and certain
other selective contaminants. They do not, however, remove or destroy
bacteria.
2. Bacteriostatic water filters are also generally comprised of activated
carbon and remove the same undersirable contaminants as the water
filters but, additionally are impregnated with a chemical agent such
as silver ions to hinder the growth of bacteria that may become
trapped within the filter.
3. Water purifiers are designed to treat raw water of unknown quality
and render it suitable for human consumption. A purifier, by
definition, must kill or remove essentially all bacteria present.
These products are further subdivided as (a) pesticidal devices where
purification is brought about purely by physical or mechanical means
such as filtration, heating, etc., where no antimicrobial chemical
agent is involved and (b) pesticides where purification is achieved
through the use of antimicrobial agents incorporated within the
product.
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Within the breakdown of units as described above, bacteriostatic
water filters and pesticides are required to be registered with EPA
before being legally held or offered for sale. In addition Facilities
producing Bacteriostatic Water filters and pestlcldal devices, and
pesticides are required to show an EPA establishment registration number.
This establishment registration number Indicates that the facility producing
the unit deals with pesticides and that it is subject to EPA routine
investigations with respect to recordkeeping, production, storage, shipping
procedures, etc. Registration as such does not imply EPA approval or
endorsement.
The majority of water filters being purchased are of the activated carbon
type. Activated carbon is a form of carbon that is modified by a
carefully controlled oxidation process to develop a porous carbon structure
with a large surface area. Some of the raw materials are coal, wood, nut
shells, peat, lignite and residue from petroleum processes. The large
surface and high porosity give activated carbon unique adsorptive
properties. Adsorption is the process whereby a material (adsorbate)
moves from the solution phase to the surface of an adsorbent (carbon) and
held by attractive forces. Activated carbon has a preference
for most organic compounds and therefore is effective in removing
compounds which may cause taste and odor problems In water supplies. Many
engineering and other technical factors are involved in the actual
adsorptive capacity which determine how much and what chemicals can be
removed by carbon treatment. A problem exists in that certain chemicals
can be removed by carbon, but different percentages of removal can be
achieved depending on influent concentration, flow rate, contact time,
amount of carbon, and particle size of the carbon. A smaller particle
size generally allows better removal because more surface area is utilized.
Longer contact time and slower flow rates also allow higher percentage of
removal.
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The carbon filter units come In basically five types:
1) Pour ~ Through - You run water thru a filter into a collecting
vessel.
2) Faucet - Attached to the end of your faucet.
3) Stationary - These attach to the cold water pipe under the
sink.
4) Line - Bypass - These attach to the cold water pipe under
the sink. But they have a separate faucet for just drinking
water.
5) Household - Installed where water enters your home.
A carbon filter unit will not make contaminated water safe. They will not
remove bacteria. A carbon filter will improve the taste and odor if that is
your concern and possibly some organic chemicals. A filter unit should
only be used in a source of water that is known to be bacteria free.
These units work well on public water supplies in which people do not
like the taste of chlorine. Carbon units remove chlorine very effectively.
The Environmental Protection Agency tested over thirty units for their
effectiveness in removing various organic contaminants. A summary of the
results is enclosed (TABLE 1). Also a summary of a study done by consumer
reports is included (TABLE 2). Carbon filters will not remove bacteria,
calcium and magnesium (hard water), fluorides, nitrates, chlorides. They
remove a very small percentage of inorganic chemicals.
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Since the units come in all different types and prices, the most common
question is, what unit should I purchase? This is going to depend upon
your personal needs. A cheap pour through unit might be able to produce
water with no chlorine taste, but is time consuming and perhaps inconvenient.
The more expensive by-pass units have proven most effective in taking out
organic contaminants. If you have the initiative, a plan is enclosed for
building your own carbon filter.
If you do use an activated carbon filter, there are several suggestions
you should follow:
- Watch for any signs of sediment in the water.
- If the water pressure becomes noticeably reduced, its time
to change the filter.
- A change in taste could mean breakthrough of the filter has
occurred. Breakthrough is when the carbon is no longer
removing a contaminant, and it is time to change the filter.
- Flush out the filter before the first use of the day. The
faucet should be opened fully for 30 seconds.
- Always filter cold water.
- Filter at slowest possible rate.
- Always follow the manufacturers recommended times for changing
the filter cartridges.
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OTHER TYPES OF HOME
TREATMENT UNITS
REVERSE OSMOSIS
Osmosis is the transport of a solvent from a dilute solution to a concentrated
solution across a semipermeable membrane. For reverse osmosis to
work the pressure is increased on the solution side of the membrane. The
home reverse osmosis units will require a certain line pressure specified
by each manufacturer.
A membrane can be defined as a phase which acts as a barrier to the flow
of molecular or ionic species between other phases that it separates.
The most widely used membrane is the modified cellulose acetate film.
These membranes reject a variety of materials.
The following substances are removed very effectively with home reverse
osmosis units:
Magnesium
Sodium
Iron
Manganese
Aluminum
Chromium
Ammonia
Fluoride
High molecular weight Organics> 200 (although some lower molecular
weight organics are removed there is no simple way to predict
which ones). Reverse Osmosis alone does not reduce trihalomethanes*
significantly.
Calcium
Hardness
*See Appendix
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The trihalomethanes group includes the following compounds:
Compound
Molecular Weight
Chloroform
119
Bromodichloromethane
163
Dlbromochloromethane
208
Bromoform
252
ION EXCHANGE
Ion exchange units are used primarily at the home for softening water.
Calcium and magnesium are the prime constitutents of hardness. In the
cation-exchange softening process calcium and magnesium are removed and
replaced by sodium. For individuals on a sodium restricted diets, this
obviously would not be the process of choice.
Ion exchange is a process in which ions are exchanged for ions of a
similar charge in a solution in which the solid is immersed.
Some substances dissolved in water are capable of conducting electricity.
The substances are called electrolytes. When an electrolyte dissolves in
water its molecues disassociate Immediately into oppositely charged
fragments or ions. Positive Ions are cations and negative ions are
anions. An example is Salt (NaCl), which when dissolved disassociates
into Na (Cation) and CI (Anion).
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Distillation
Distillation is the process of driving gas or vapors from water by heating
and condensing the water to a new liquid product. Basically the impurities
should be left behind and uncontaminated water condenses to form a clean
end product.
A problem does exist, in that certain contaminants have a lower boiling
point than water. These chemicals could vaporize with the water and end
up in the final liquid product.
Fortunately most of the distillers for home use utilize the process called
fractional distillation. In this process the components of water are
separated from one another by taking advantage of the differences in
their voltilities. Obviously this is the type of distiller most people
would be interested in purchasing.
They do take a lot of water to utilize, energy to heat the water, and the
initial price can be expensive.
Boiling
If your major drinking water concern is trihalomethanes or any
of the volatile organics such as vinyl chloride or trichloroethylene,
boiling might be an alternative.
Although boiling is both time consuming and energy consuming it will
drive off most trihalomethanes after 5 minutes and most volatile organics
after 10 minutes. It should be noted that inorganic chemicals will be
concentrated during the boiling process. Simply warming the water will
do no good and may actually increase the amount of trihalomethanes.
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In 1974 the Safe Drinking Water Act was passed by Congress. From this
Act, regulations governing levels of many chemicals, including: Arsenic,
Barium, Cadmium, Chromium, Lead, Mercury, Nitrate, Selenium, Silver,
Fluoride, Pesticides, Radioactivity, Bacteria, Trihalomethanes,* and
Sodium have come into being. These parameters are now required to be
analyzed for every community water system. If you have any doubts about
any of these contaminants, contact your local water system. They will
have analyzes records for each chemical. The only exception is small
water systems serving less than 10,000 people are not required to analyze
the water for trihalomethanes.
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TABLE I
Information on Units Tested
Average
Reductions
Name
4-1 0)
CO M-l
4-»
< o
• 4J
4-» e
W o
(sec)
n-i
o
•u c
x: o
M XI
-r-t M
0) «
(gms)
THM
(%)
NPT0C
(%)
Faucet-Bypass
1. Aquaguard, Model
AGT-31, Cartridge T-3XL
500
3.4
51
43
12
2. Concept Bacteriostatic
Home Water Filter
40
1.6
N/A1
16
18
3. Filter Fresh Model
FF-1
1200
4.8
59
6
6
4. Hurley Town and
Country
4000
36.5
895
69
31
5. Water Washer,
Countertop Model 1000
1000
10.9
70
41
11
Pour-Through
6. Filbrook Pour-Thru
Activated Carbon
1000
43.8
97
40
14
7. Puritan Bacteriostatic
Drinking Water Treatment Unit
1000
14.1
30
21
6
Stationary
8. AMF-Cuno Housing 1M
Cartridge AP-117
3000
3.9
395
34
7
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Information on Units Tested
Average
Rerliir H nnc
Name
0)
6
•H
THM
NPTOC
Test
Life
Est. Ave.
Contact T
Weight of
Carbon
(%)
(%)
(gal)
(sec)
(gms)
9. Filtrate, Model
1 PC Cartridge 1C-9
3000
1.2
N/A
18
8
10. Fulfo Water Filter
Model WC-10
3000
2.6
208
15
11
11. Keystone Model 3121
Housing with Model 310
Cartridge
3000
2.3
N/A
21
9
Line-Bypass
12. Aquacell Bacteriostatic
Water Treatment Unit
2000
12.4
417
86
23
13. Aqualux Water
Processor, Model CB-2
2000
35.2
1150
98
23
14. Argenion Bacteriostatic
Water Treatment Unit, Model 1
2000
8.1
146
23
N/A
15. Continental Water Filter
Model 350
720
185
3402
99
87
16. Culligan Super Guard
Model SG-2
4000
39
1708
89
28
17. Everpure, Model
QC4-THM
1000
43
765
99
55
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Average
Information on Units Tested
Reductions
Name
0)
E
THM
NPT0C
n
• H
n)
U-l
O
(%)
<%)
Test
Life
Est. Avi
Contact
Weight (
Carbon
(gal)
(sec)
(gms)
18. Mariner Renaturalizer
3000
31.4
560
47
21
Water Units
19. Polarisdynamic
Water Unit
2500
26.6
527
61
18
20. Purogen Water
Detoxifier
2500
11.6
859
38
6
21. Seagull IV
1600
14.8
300
70
30
22. Ultrapure Bacteriostatic
3000
28.0
L103
40
20
23. Waterco, Model
AS-5
3000
5.0
495
25
N/A
Other
24. Wunderbar, Portable
Water Cleaner-Filter
200
0.9
N/A
4
N/A
PHASE I - Commercial
Faucet-Bypass
25. Instapure Model
Fl-C
200
1.6
27
24
11
Faucet-No Bypass
26. Mini Aqua Filter
200
0.9
16
6
2
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Information on Units Tested
Average
Reductions
Name
CO M-j
0) *H
H hJ
(gal) (sec)
Q)
B
•H
• H
0)
j> 4J
< O
cd
• 4->
¦U C
en o
W O
THM
(%)
•W c
JZ o
CxO ^
«H M
0) 03
£ u
(fims)
Pour-Through
27.
H2OK Portable
Drinking Water Treatment
Unit
Stationary
28. Sears Taste and
Odor Filter
Line-Bypass
29. Aqualux Water
Processor, Model HB
30. System 1 Water
Processor, Model
SY1-34
PHASE II
Experimental-Unique Resin
31. Rohm and Haas
Ambersorb XE-340
1 N/A - Not Applicable
2000
15
94
3420
4.5
398
2000
2500
23
46
575
1120
3500
50.6
2353
19
46
45
43
93
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CONSUMERS REPORT
Listed by types; within types, listed
in order of estimated number of
gallons of water effectively fil-
tered to reduce chloroform. Brack-
eted models are Judged similar in
ability to remove chloroform and
are listed In order of Increasing
price. Estimated filter lifetime is for
guidance; actual lifetime may
vary greatly according to loccd
water quality. All come with instal-
lation Instructions and mounting
hardware. Under-sink models may
require installation by licensed
plumber. Except as noted, sink-
mounted models fit on faucet end.
Prices are suggested retail and do
not Include cost of installation;
Chloroform
removal
prices in parentheses are for re-
placement filter cartridges; 'indi-
cates that price is approximate; +
Indicates that shipping is extra. Dis-
counts may be available.
© © O Q •
EBY TO COEftMSMTS
A- Water flow restricted by fitter's design.
B-Requires IMn. tubing (supplied).
C-Supplied with outlet faucet fixture.
D- Supplied with wrench to open housing.
E-Registered a* "purifier" with EPA.
F-Manufacturer claims that unit can filter
out particles leu than 1 micron dla. CU
believes unit may clog prematurely In
turbid water.
6-Silver Incorporated Into fBter; bacterio-
static properties claimed, but not verifi-
ed by CU (see story).
H-Transparent plastic housing; cartridge
visible in use, an odvantoge.
I-Design Incorporates cartridge change-
date reminder, an advantage.
J-Locks pressure relief button on top of ti-
ter housing, a tfisadvantage.
K-Would rate higher If used with water sup-
ples that have no sediment problem.
L-FBter unit sits on counter and is connect-
ed by hose to divert or valve on faucet.
M-Back washing to clean filter recom-
mended by manufacturer at 145°F. an
advantage If you have water that hot;
back washing can extend Ifetime of fB-
ter.
N-No replaceable cartridge avaSable; en-
tire unit must be returned to mcnufoctur-
er for refill ($50).
O-FBter contains much more cabon than
others of this type. Estimated Bfettme
may exceed 3000 gal. toted.
P-According to the company. fBter hous-
ing tested has been replaced by a differ-
ent model (not tested). Replaceable
cartridge MAS1. Judaea most affective
of Its type. Is still available.
Q-Chloroform-removal level never
reached 25 percent in CU's test.
R-Oocro cartridge also fits thb unit.
S-Cartridges sow only In packs of 2 for $15.
Price given is for comparison purposes.
T-Avalable from Universal Water Systems
Inc., 705 E. State St., Geneva, S. 60134.
U-AvaSable from Rush Hampton lnd„ P.O.
Box 3000, Longwood. Fla. 32750.
FEBRUARY 1983
Under-sink model*
CULUOAN SUPEB OARD 80-1
$175,($23* ) 5x16 In. 3000 gal.
® ©
@ G
A.B.O
SEARS MM, A BUST BUY
20 *(7.50)
5x12 1200
© @
@ G
D.P£
AMP-CUNO AP50T
67(12)
4»x14tt 1200
© ©
@ G
H
tIAOUU. IV X-W
290(40)
5x6* 1200
© o
® Pb A.B.C.E.F.K
PUIAO WCU
51(8.85)
5x13 300
o @
© G
D.H.J.R
a The following 3 models were Judged much less effective than those precedng. in oddttion.
they "unloaded." or returned, some chloroform to tap water when used for more than 300
gal. All may be satisfactory for removing some tastes and odors, however.
AQUA OUABO AOT200 37+(6.25+) 4lx12K 150 © ® ® P H.R.T
KEYSTONE 2111
44(6.75)
5x13 150
© @
© P
H.R
PILTEBITE IPC
55(9)
6»x12K 150
© @
® p
H.J
Sink-mounted models
HUBLEY TOWN fi COUNTRY
190(47 + )
611x10* 3000
9 @
© G
A.L.M.N.O
ECOLOOIZEB WAT2B
TBEATMEMT SYSTEM 900S
35+(10+)
4x6 250
O © © <5
AX.I.L.U
POUENEX PUBE WATBB 'W
35(4.95)
5*x5 150
© o
© G
A
AQUA OUABO AOT-SM
30 + (3.50 + )
4x4* 100
© O O g
H.T
D The following 2 models were fijdged much less effective than those preceding because they
never achieved cMoroform-removatlevei of 50porcent in CU's tests.
IMSTAPUBE BY WATCB PEK P-1C 34(4) 5x3% — © Q © ® —
PEEBLES* BPS5M
20(4)
3*x3 —
© © © p
F.G.K.Q
H Lifetime, as determined by CU. ts number of actions during which removal of chloroform b
expected to be greater than SO percent. Ufetlmes of 1000 gat. or more are combination of
CU and EPA test results.
B] Chlorine removal judged with tnused cartridge tor first few gal. only.
~I G. granular; Pb. powder in block: P. powder In pad.
72
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Appendix 2
HOME TREATMENT UNIT FACT SHEET
This fact sheet is intended to explain what a home treatment unit is, what it
will do and why it is registered with EPA. The fact sheet is intended for
consumers who are considering purchasing a unit and for salespeople. Before
considering any unit, a prospective salesperson or consumer should contact the
associated water utility to obtain information about the quality of water to be
treated.
WHAT IS A HOME TREATMENT UNIT
For the purposes of this fact sheet, a home treatment unit will be defined as a
unit used at the consumers tap to treat water which already meets the EPA
national drinking water standards. The benefits are usually non-health related.
Home treatment units contain one or a combination of the following processes.
1) Granular Activated Carbon
2) Ion-Exchange Softening
SOFTENERS
Most commercial softeners are sodium exchange softeners. They remove hardness
(mostly calcium, manganese, iron, and magnesium) from the water and replace it
with sodium.
ADVANTAGES OF SODIUM EXCHANGE SOFTENING
° Will reduce iron and manganese concentrations. This is advantageous
when the initial concentrations are high enough to be a nuisance
(staining fixtures, clothes, etc.).
0 Will provide cost savings on soap and detergents.
° Will reduce film on dishes, skin, etc., when washing.
° Might reduce calcium carbonate deposits in plumbing.
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DISADVANTAGES OF SODIUM EXCHANGE SOFTENING
0 Will make a corrosive water supply more corrosive, reducing the life
of plumbing.
° People on a low sodium diet might not be able to drink the water.
° Units are generally expensive ($1,000 - $2,000).
° Unit must be maintained.
0 Disposal of waste brine may be a problem.
QUESTIONS TO ASK ABOUT SOFTENERS
° How does one know when the unit needs recharging?
° How is the unit recharged and who does it?
° How much sodium will the unit put into the water? (i.e., what will be
the concentration of sodium in the water flowing out of the unit?)
° How much are the maintenance costs?
ACTIVATED CARBON FILTERS
If given sufficient time for the water to remain in contact with the carbon,
activated carbon will remove most organics to varying degrees and some inorganics
(including chlorine). Removals will generally start off high and steadily
decrease as the unit is used. Activated carbon works by a principle called
adsorption where chemicals are trapped in the large surface area of the carbon.
The chemicals should remain attached to the carbon, if it is properly maintained,
until the carbon is reactivated.
ADVANTAGES OF ACTIVATED CARBON FILTERING
° Will remove bad tastes, odor, and color.
° Might reduce some organic chemicals that could cause a health risk if
the chemicals are present in the drinking water.
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